My main focus, evident in my websites, blog and articles, is to develop theories that help to integrate cognitive psychology, clinical neuroscience and integrative biology.
The present article examines several lines of converging evidence suggesting that the slow and in... more The present article examines several lines of converging evidence suggesting that the slow and insidious brain changes that accumulate over the lifespan, resulting in both natural cognitive aging and Alzheimer's disease (AD), represent a metabolism reduction program. A number of such adaptive programs are known to accompany aging and are thought to have decreased energy requirements for ancestral hunter-gatherers in their 30s, 40s and 50s. Foraging ability in modern hunter-gatherers declines rapidly, more than a decade before the average terminal age of 55 years. Given this, the human brain would have been a tremendous metabolic liability that must have been advantageously tempered by the early cellular and molecular changes of AD which begin to accumulate in all humans during early adulthood. Before the recent lengthening of life span, individuals in the ancestral environment died well before this metabolism reduction program resulted in clinical AD, thus there was never any selective pressure to keep adaptive changes from progressing to a maladaptive extent.
Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce ... more Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce hypometabolism and decreasing synaptic density in the hippocampus and the prefrontal cortex (PFC). This article evaluates and explores evidence supporting the hypothesis that these, and other, selective effects of prolonged stress constitute a neuroecological program that adaptively modifies behavior in mammals experiencing adverse conditions. Three complementary hypotheses are proposed: (1) chronic stress signifies that the prevailing environment is life-threatening, indicating that the animal should decrease activity in brain areas capable of inhibiting the stress axis; (2) stress signifies that the environment is unpredictable, that high-level cognition may be less effective, and that the animal should increase its reliance on defensive, procedural and instinctual behaviors mediated by lower brain centers; and (3) stress indicates that environmental events are proving difficult to systemize based on delayed associations, and thus the maintenance of contextual, task-relevant information in the PFC need not be maintained for temporally-extended periods. Humans, along with countless other species of vertebrates, have been shown to make predictive, adaptive responses to chronic stress in many systems including metabolic, cardiovascular, neuroendocrine, and even amygdalar and striatal systems. It is proposed in this article that humans and other mammals may also have an inducible, cerebrocortical response to pronounced stress that mediates a transition from time-intensive, explicit (controlled/attentional/top-down) processing of information to quick, implicit (automatic/preattentive/bottom-up) processing.
This article provides an analytical framework for how to simulate human-like thought processes wi... more This article provides an analytical framework for how to simulate human-like thought processes within a computer. It describes how attention and memory should be structured, updated, and utilized to search for associative additions to the stream of thought. The focus is on replicating the mammalian working memory system, which features two forms of persistent activity: sustained firing (preserving information on the order of seconds) and synaptic potentiation (preserving information from minutes to hours). The article uses a series of over 40 original figures to systematically demonstrate how the iterative updating of these working memory stores provides functional structure to thought and consciousness.
In an AI implementation, these two stores should be updated continuously and in an iterative fashion, meaning each state should preserve a proportion of the coactive representations from the state before it. Thus, the set of concepts in working memory will evolve gradually and incrementally over time. This makes each state a revised iteration of the preceding state and causes successive states to overlap and blend with respect to the information they contain. Transitions between states happen as persistent activity spreads activation energy throughout the hierarchical network searching long-term memory for the most appropriate representation to be added to the global workspace. The result is a chain of associatively linked intermediate states capable of advancing toward a solution or goal. Iterative updating is conceptualized here as an information processing strategy, a model of working memory, a theory of consciousness, and an algorithm for designing and programming artificial general intelligence.
It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and a... more It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and associated comorbidities is largely a product of our modern environment. Artificially high levels of sugars, fats, and processed foods, along with sedentary behavior constitute an “obesogenic” environment which makes us more susceptible to the metabolic syndrome today than our foraging ancestors were millennia ago. A number of comparative analyses relevant to the influence of behavior, diet, and nutrition on the metabolic syndrome are reviewed here, especially with regard to the developmental origins of the syndrome. It has become clear that early environmental conditions, particularly poor nutrition, have the ability to act as cues that program the phenotype in utero. It is thought that the fetus has an adaptive ability to perceive nutritional deprivation, and reprogram its metabolic systems for energy efficiency, as a predictive response to expected environmental scarcity. These metabolic alterations are thought to be beneficial in times of poor nutritional quality, but unfortunately have consistently been shown to result in adverse health outcomes and metabolic disease, when food is calorie dense and readily available. These early life changes are brought about by alterations in cellular proliferation and differentiation that are ultimately driven by neuroendocrine, cellular, and epigenetic adaptations to undernutrition. Besides the various metabolic changes, animals programmed for thrift have been shown to exhibit neurological changes resulting in hyperphagia, increased sedentariness, and volume reductions in the cerebral cortex. A great deal of evidence, including countless animal studies and a worldwide series of epidemiological investigations, has supported the close relationship between early nutritional status and susceptibility to the major risk factors (increased adiposity, hypertension, and insulin resistance) for the metabolic syndrome in later life. The perspectives originated by James Neel (the thrifty genotype hypothesis), and David Barker (the thrifty phenotype hypothesis) have remained important interpretations through which to view the nature of the genetic, structural, and adaptive facets of the programming of metabolic function. Moreover, these perspectives, and the integrative conceptualizations that they promote, have begun to provide valuable direction for research and health care.
Tourette syndrome, and the closely related spectrum of tic disorders, are inherited neuropsychiat... more Tourette syndrome, and the closely related spectrum of tic disorders, are inherited neuropsychiatric conditions characterized by the presence of repetitive and stereotyped movements. Tics are elicited by either environmental experiences or internal signals that instruct the basal ganglia to initiate automatic or procedural movements. In most vertebrates the basal ganglia encode instructions for habitually used sequences of motor movements that are essential to survival. Tic disorders may represent evolved phenotypes with a lower threshold for basal ganglia-directed actions. This may have produced a susceptibility to extraneous tics, but also produced fast-acting tactical solutions to immediate physical problems. During periods of nonstop movement, continual foraging, and sustained vigilance, it may have been advantageous to allow subcortical motor commands to intrude into ongoing motor activities. It is clear that the engrams for individual motor responses held in the basal ganglia are selected by converging cortical and subcortical inputs. This form of convergent action selection results in the selection of the most contextually reinforced actions. Today people with Tourette's have tics that seem arbitrary and inappropriate; however, this may be due to the vast discrepancies in reinforcement between the ancestral environment and the modern one. In prehistoric environments, the motor behaviors of individuals with tic disorders may have been appropriate in environmental context, and had ecological relevance in survival and self-promotion.
It is well recognized that investigation into the relationship between early life programming and... more It is well recognized that investigation into the relationship between early life programming and subsequent neurological disorders may have powerful implications for understanding the human vulnerability to psychopathology. The present article will propose that schizophrenia may be adaptively programmed by early environmental adversity permitting physiological and behavioral characteristics that would have created a fitness advantage in the ancestral environment under conditions of nutritional scarcity and severe environmental stress. This proposition will be analyzed in terms of phenotypic plasticity theory which explains how and why specific environmental stressors can alter normal gene expression resulting in an alternative phenotype that is better suited for an adverse environment. The primary neurophysiological symptoms of schizophrenia can be induced in animals through exposure to prenatal and postnatal stressors, and that schizophrenia itself is known to be associated with exposure to stress during development, supports the view that the "disorder" may represent a predictive, adaptive response to adversity. In fact, maternal malnutrition, maternal stress, multiparity, short birth interval and stress provoking postnatal events are well recognized epidemiological risk factors for schizophrenia that may represent cues for the initiation of epigenetic programming. Behavioral and physiological characteristics of schizophrenia will be analyzed and interpreted as protective in the context of environmental hardship. For instance, the hypometabolic areas of the schizophrenic brain--the hippocampus and the frontal lobes--are the same areas that are known to become adaptively hypometabolic in response to starvation, stress and variations in ecological rigor in birds and mammals. Individuals with schizophrenia are also highly genetically inclined to develop the metabolic syndrome, which is widely thought to allow developmentally deprived mammals to conserve energy under poor circumstances. It is well known that schizophrenia features an up-regulated hypothalamic-pituitary-adrenal axis and an exaggerated stress response--both alterations thought to represent predictive, adaptive responses to stress in mammals--which may have increased attentiveness to the environment and created a defensive, vigilance-based behavioral strategy. The habituation deficits characteristic of schizophrenia--which can be induced in other mammals through stress--may represent a cognitive strategy that alerts the organism to salient, potentially informative stimuli and that permits it to be more impulsive and vigilant. Inability to calm instinctual drives, ignore arousing stimuli, and inhibit transient desires are all core characteristics of the disorder, which predict social and vocational disabilities in modern times, but may have amounted to a robust, selfish strategy in prehistoric times.
This article will suggest that moderate sleep apnea may have an adaptive benefit, the reduction o... more This article will suggest that moderate sleep apnea may have an adaptive benefit, the reduction of nocturnal, respiratory heat loss, that may have caused it to be selected for despite the associated disadvantages. Sleep apnea is caused by the collapse of the throat, specifically the pharyngeal airway, during sleep and can result in discomfort and hypoxia. The large size of the fleshy structures in the pharynx and hypotonicity of the pharyngeal musculature are what cause humans, and many other species of mammals, to be susceptible to apnea. There are many functional and anatomical parallels between sleep apnea and a well known, thermoregulatory response that minimizes respiratory cooling in the lower airways known as reflex bronchoconstriction. Bronchoconstriction involves the constriction of the inner airways, the bronchioles, in response to cold air, a reaction that acts to warm inspired air before it makes contact with the more sensitive lower airways and alveoli. Because air is colder at night and body temperature drops severely during sleep, sleep apnea may represent a similar protective, thermoregulatory adaptation. When the pharynx is collapsed, the diameter of the pharyngeal airway decreases, allowing increased intermolecular collisions between inspired air and the epithelial walls of the upper airway. An increase in the number of collisions facilitates the transference of both warmth and humidity to inspired air before it reaches the more sensitive lower airway resulting in the maintenance of internal, core temperature and alveolar heat retention. In fact, sleep apnea can be conceptualized as a functional reversal of the thermoregulatory process of panting, where the pharynx is highly dilated instead of collapsed. Given the disorder associated with sleep apnea, the absence of a disease state secondary to surgical correction, the fact that the disorder is exclusive to warm-blooded animals, the high proclivity for collapse documented in pregnant mothers, and the functional similarities between collapse and reflex bronchoconstriction, it appears that the phenomenon may represent an evolutionary trade-off that helped to minimize respiratory cooling.
This paper will suggest that the Down syndrome phenotype would have been well suited, physiologic... more This paper will suggest that the Down syndrome phenotype would have been well suited, physiologically, for a deprived environment and that it may represent a predictive, adaptive response to severe maternal deprivation. A trisomy of the 21st chromosome, prior to, or at conception is responsible for Down syndrome and is known to increase in incidence with advanced maternal age. One out of 11 mothers over the age of 50 conceives a Down syndrome baby, compared to one in one thousand at age 30. This article emphasizes that an older mother is more likely to die before she is able to provide the parental investment necessary to produce an ecologically selfsufficient offspring. Prolonged maternal investment is known to be essential for hunter-gatherers to master the skill intensive food procurement techniques that they will need in order to become independent of their mothers. Because Down syndrome individuals are much more likely to be born to older mothers, they must have been routinely deprived of maternal investment in the human environment of evolutionary adaptedness. This consistent paring of maternal deprivation to trisomy 21 conceptions, over time, may have caused natural selection to favor genes responsible for the energy conserving traits seen in modern day Down syndrome. These traits include muscle hypotonia, decreased cerebral metabolism, decreased hippocampal volume, a strong propensity for obesity and growth hormone and thyroid hormone paucity. Such a "thrifty phenotype" may have allowed Down syndrome individuals to become independent of their mothers at a far earlier age and allowed them to forgo the skill intensive ecological niche that non-trisomic humans are phenotypically suited for in order to take up a less cognitively and physically rigorous one.
This article will propose that humans have an adaptive vulnerability to certain forms of mental r... more This article will propose that humans have an adaptive vulnerability to certain forms of mental retardation, specifically, neuropathological disorders that cause decreased energy expenditure in the hippocampus and the cerebral cortex. This hypothesis will be analyzed in terms of the thrifty phenotype paradigm according to which adverse prenatal events can cause differential gene expression resulting in a phenotype that is better suited, metabolically, for a deprived environment. For example, a malnourished mother has an increased propensity to give birth to offspring that feature a ''thrifty phenotype'' which permits highly efficient calorie utilization, increased fat deposition and a sedentary nature. This article interprets several prenatal occurrences, including maternal malnourishment, low birth weight, multiparity, short birth interval, advanced maternal age and maternal stresswhich are currently identified by the epidemiological literature as risk factors for neuropathology-to be environmental cues that communicate to the fetus that, because it will be neglected of maternal investment, developing a metabolically conservative brain will be the most effective ecological strategy. Success in hunting and foraging in mammals, primates and especially humans is known to be dependent on prolonged maternal investment. Low levels of maternal care are known to result in low survivorship of offspring, largely because the offspring are forced to subsist using simple, low-yield foraging strategies. A predictive, adaptive response, marked by cerebral hypometabolism, may produce a level of metabolic conservancy that mitigates the risks associated with low levels of maternal care. This article will suggest that certain, human neuropathological phenotypes would have been well suited for an ecological niche that closely resembled the less skill-intensive niche of our less encephalized, primate ancestors. The forms of congenital neuropathology discussed in this article do not cause damage to vital homeostatic systems; most simply decrease the size and energy expenditure of the cerebral cortex and the hippocampus, the two structures known to show plasticity during changes in ecological rigor in vertebrates. Also, many disorders that present comorbidly with neuropathology, such as tendency toward obesity, decrement in anabolic hormones, hypotonic musculature, up-regulation of the hypothalamic-pituitary-adrenal axis, and decreased thyroid output are associated with energy conservancy and the thrifty phenotype, further implicating neuropathology in an ecological strategy.
This article presents an artificial intelligence (AI) architecture intended to simulate the human... more This article presents an artificial intelligence (AI) architecture intended to simulate the human working memory system as well as the manner in which it is updated iteratively. It features several interconnected neural networks designed to emulate the specialized modules of the cerebral cortex. These are structured hierarchically and integrated into a global workspace. They are capable of temporarily maintaining high-level patterns akin to the psychological items maintained in working memory. This maintenance is made possible by persistent neural activity in the form of two modalities: sustained neural firing (resulting in a focus of attention) and synaptic potentiation (resulting in a short-term store). This persistent activity is updated iteratively resulting in incremental changes to the content of the working memory system. As the content stored in working memory gradually evolves, successive states overlap and are continuous with one another. The present article will explore how this architecture can lead to gradual shift in the distribution of coactive representations, ultimately leading to mental continuity between processing states, and thus to human-like cognition.
The term state-spanning coactivity (SSC) is introduced to refer to shared content between success... more The term state-spanning coactivity (SSC) is introduced to refer to shared content between successive brain states. • SSC is made possible by sustained firing, binding, and recurrent processing. • Sustained activity ensures that consecutive topographic maps are interrelated. • SSC also permits continuous, algorithmic, and progressive alterations to mental imagery. • Incremental change in SSC (icSSC) allows the continuity necessary for updating, modeling, and systemization.
This book examines the foundations of personal belief by conducting a review of classical and con... more This book examines the foundations of personal belief by conducting a review of classical and contemporary thought about beliefs, by experimenting with new and innovative ways to conceptualize beliefs and by presenting new evidence about beliefs from empirical studies. Beliefs, although often vaguely defined in discourse, can be conceptualized in many different ways: as associative memories; as coactivations between multiple neural assemblies; as functional cognitive instruments; as self- propagating entities that parasitize minds; as the firings of a certainty module in the brain; as placeholders for self-identity; or as means by which to make sense out of the world. This book explores each of these very different facets of belief in an endeavor to explicate the origins and dynamics of believing. Concepts that are considered include personal epistemology, delusional thinking, unconscious processes, the neurobiology of belief, the ontology of belief, and the evolutionary pressures on belief accuracy. The viewpoints garnered, although they come from disparate fields, interface in provocative ways and taken together, paint a rich portrait of the mechanics of belief.
This article reviews etiological and comparative evidence supporting the hypothesis that some gen... more This article reviews etiological and comparative evidence supporting the hypothesis that some genes associated with the autism spectrum were naturally selected and represent the adaptive benefits of being cognitively suited for solitary foraging. People on the autism spectrum are conceptualized here as ecologically competent individuals that could have been adept at learning and implementing hunting and gathering skills in the ancestral environment. Upon independence from their mothers, individuals on the autism spectrum may have been psychologically predisposed toward a different life-history strategy, common among mammals and even some primates, to hunt and gather primarily on their own. Many of the behavioral and cognitive tendencies that autistic individuals exhibit are viewed here as adaptations that would have complemented a solitary lifestyle. For example, the obsessive, repetitive and systemizing tendencies in autism, which can be mistakenly applied toward activities such as block stacking today, may have been focused by hunger and thirst toward successful food procurement in the ancestral past. Both solitary mammals and autistic individuals are low on measures of gregariousness, socialization, direct gazing, eye contact, facial expression, facial recognition, emotional engagement, affiliative need and other social behaviors. The evolution of the neurological tendencies in solitary species that predispose them toward being introverted and reclusive may hold important clues for the evolution of the autism spectrum and the natural selection of autism genes. Solitary animals are thought to eschew unnecessary social contact as part of a foraging strategy often due to scarcity and wide dispersal of food in their native environments. It is thought that the human ancestral environment was often nutritionally sparse as well, and this may have driven human parties to periodically disband. Inconsistencies in group size must have led to inconsistencies in the manner in which natural selection fashioned the social minds of humans, which in turn may well be responsible for the large variation in social abilities seen in human populations. This article emphasizes that individuals on the autism spectrum may have only been partially solitary, that natural selection may have only favored subclinical autistic traits and that the most severe cases of autism may be due to assortative mating.
This article presents an artificial intelligence (AI) architecture intended to simulate the human... more This article presents an artificial intelligence (AI) architecture intended to simulate the human working memory system as well as the manner in which it is updated iteratively. It features several interconnected neural networks designed to emulate the specialized modules of the cerebral cortex. These are structured hierarchically and integrated into a global workspace. They are capable of temporarily maintaining high-level patterns akin to the psychological items maintained in working memory. This maintenance is made possible by persistent neural activity in the form of two modalities: sustained neural firing (resulting in a focus of attention) and synaptic potentiation (resulting in a short-term store). This persistent activity is updated iteratively resulting in incremental changes to the content of the working memory system. As the content stored in working memory gradually evolves, successive states overlap and are continuous with one another. The present article will explore how this architecture can lead to gradual shift in the distribution of coactive representations, ultimately leading to mental continuity between processing states, and thus to human-like cognition.
This opinion article explores how sustained neural firing in association areas allows high-order ... more This opinion article explores how sustained neural firing in association areas allows high-order mental representations to be coactivated over multiple perception-action cycles, permitting sequential mental states to share overlapping content and thus be recursively interrelated. The term "state-spanning coactivity" (SSC) is introduced to refer to neural nodes that remain coactive as a group over a given period of time. SSC ensures that contextual groupings of goal or motor-relevant representations will demonstrate continuous activity over a delay period. It also allows potentially related representations to accumulate and coactivate despite delays between their initial appearances. The nodes that demonstrate SSC are a subset of the active representations from the previous state, and can act as referents to which newly introduced representations of succeeding states relate. Coactive nodes pool their spreading activity, converging on and activating new nodes, adding these t...
Individuals with schizophrenia are at a high risk of developing life-shortening illnesses and are... more Individuals with schizophrenia are at a high risk of developing life-shortening illnesses and are especially prone to developing metabolic diseases. Epidemiological evidence has demonstrated that schizophrenia is closely associated with the metabolic syndrome and its associated disorders, including type 2 diabetes mellitus, cardiovascular disease, dyslipidemia, visceral fat distribution, and hypertension. This association has been attributed to behavioral factors seen in patients with schizophrenia like poor diet, increased food intake, increased dietary fat content, lack of exercise, and reduced physical activity but there are clearly other mediating factors. Specific features of the metabolic syndrome are known to be exacerbated by severe stress and elevated levels of cortisol, elements common in schizophrenia. The antipsychotic medications widely prescribed in schizophrenia, especially the atypical antipsychotics, have been implicated in the onset and worsening of metabolic symptoms. There is also evidence pointing towards the fact that schizophrenia and the metabolic syndrome present comorbidly because of a shared genetic basis. The public health significance of these associations is clear and provides impetus for mental health professionals to become more responsible for identifying, treating, and monitoring the physical symptoms of schizophrenia in addition to the psychiatric ones. Unfortunately, health care practitioners may not place enough emphasis on the treatment of metabolic disorders in this population because of low awareness and past ambiguity of findings.
It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and a... more It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and associated comorbidities is largely a product of our modern environment. Artificially high levels of sugars, fats, and processed foods, along with sedentary behavior constitute an “obesogenic” environment which makes us more susceptible to the metabolic syndrome today than our foraging ancestors were millennia ago. A number of comparative analyses relevant to the influence of behavior, diet, and nutrition on the metabolic syndrome are reviewed here, especially with regard to the developmental origins of the syndrome. It has become clear that early environmental conditions, particularly poor nutrition, have the ability to act as cues that program the phenotype in utero. It is thought that the fetus has an adaptive ability to perceive nutritional deprivation, and reprogram its metabolic systems for energy efficiency, as a predictive response to expected environmental scarcity. These metabolic alterations are thought to be beneficial in times of poor nutritional quality, but unfortunately have consistently been shown to result in adverse health outcomes and metabolic disease, when food is calorie dense and readily available. These early life changes are brought about by alterations in cellular proliferation and differentiation that are ultimately driven by neuroendocrine, cellular, and epigenetic adaptations to undernutrition. Besides the various metabolic changes, animals programmed for thrift have been shown to exhibit neurological changes resulting in hyperphagia, increased sedentariness, and volume reductions in the cerebral cortex. A great deal of evidence, including countless animal studies and a worldwide series of epidemiological investigations, has supported the close relationship between early nutritional status and susceptibility to the major risk factors (increased adiposity, hypertension, and insulin resistance) for the metabolic syndrome in later life. The perspectives originated by James Neel (the thrifty genotype hypothesis), and David Barker (the thrifty phenotype hypothesis) have remained important interpretations through which to view the nature of the genetic, structural, and adaptive facets of the programming of metabolic function. Moreover, these perspectives, and the integrative conceptualizations that they promote, have begun to provide valuable direction for research and health care.
This article will propose that humans have an adaptive vulnerability to certain forms of mental r... more This article will propose that humans have an adaptive vulnerability to certain forms of mental retardation, specifically, neuropathological disorders that cause decreased energy expenditure in the hippocampus and the cerebral cortex. This hypothesis will be analyzed in terms of the thrifty phenotype paradigm according to which adverse prenatal events can cause differential gene expression resulting in a phenotype that is better suited, metabolically, for a deprived environment. For example, a malnourished mother has an increased propensity to give birth to offspring that feature a ''thrifty phenotype'' which permits highly efficient calorie utilization, increased fat deposition and a sedentary nature. This article interprets several prenatal occurrences, including maternal malnourishment, low birth weight, multiparity, short birth interval, advanced maternal age and maternal stresswhich are currently identified by the epidemiological literature as risk factors for neuropathology-to be environmental cues that communicate to the fetus that, because it will be neglected of maternal investment, developing a metabolically conservative brain will be the most effective ecological strategy. Success in hunting and foraging in mammals, primates and especially humans is known to be dependent on prolonged maternal investment. Low levels of maternal care are known to result in low survivorship of offspring, largely because the offspring are forced to subsist using simple, low-yield foraging strategies. A predictive, adaptive response, marked by cerebral hypometabolism, may produce a level of metabolic conservancy that mitigates the risks associated with low levels of maternal care. This article will suggest that certain, human neuropathological phenotypes would have been well suited for an ecological niche that closely resembled the less skill-intensive niche of our less encephalized, primate ancestors. The forms of congenital neuropathology discussed in this article do not cause damage to vital homeostatic systems; most simply decrease the size and energy expenditure of the cerebral cortex and the hippocampus, the two structures known to show plasticity during changes in ecological rigor in vertebrates. Also, many disorders that present comorbidly with neuropathology, such as tendency toward obesity, decrement in anabolic hormones, hypotonic musculature, up-regulation of the hypothalamic-pituitary-adrenal axis, and decreased thyroid output are associated with energy conservancy and the thrifty phenotype, further implicating neuropathology in an ecological strategy.
Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce ... more Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce hypometabolism and decreasing synaptic density in the hippocampus and the prefrontal cortex (PFC). This article evaluates and explores evidence supporting the hypothesis that these, and other, selective effects of prolonged stress constitute a neuroecological program that adaptively modifies behavior in mammals experiencing adverse conditions. Three complementary hypotheses are proposed: (1) chronic stress signifies that the prevailing environment is life-threatening, indicating that the animal should decrease activity in brain areas capable of inhibiting the stress axis; (2) stress signifies that the environment is unpredictable, that high-level cognition may be less effective, and that the animal should increase its reliance on defensive, procedural and instinctual behaviors mediated by lower brain centers; and (3) stress indicates that environmental events are proving difficult to sys...
This opinion article explores how sustained neural firing in association areas allows high-order ... more This opinion article explores how sustained neural firing in association areas allows high-order mental representations to be coactivated over multiple perception-action cycles, permitting sequential mental states to share overlapping content and thus be recursively interrelated. The term "state-spanning coactivity" (SSC) is introduced to refer to neural nodes that remain coactive as a group over a given period of time. SSC ensures that contextual groupings of goal or motor-relevant representations will demonstrate continuous activity over a delay period. It also allows potentially related representations to accumulate and coactivate despite delays between their initial appearances. The nodes that demonstrate SSC are a subset of the active representations from the previous state, and can act as referents to which newly introduced representations of succeeding states relate. Coactive nodes pool their spreading activity, converging on and activating new nodes, adding these t...
The present article examines several lines of converging evidence suggesting that the slow and in... more The present article examines several lines of converging evidence suggesting that the slow and insidious brain changes that accumulate over the lifespan, resulting in both natural cognitive aging and Alzheimer's disease (AD), represent a metabolism reduction program. A number of such adaptive programs are known to accompany aging and are thought to have decreased energy requirements for ancestral hunter-gatherers in their 30s, 40s and 50s. Foraging ability in modern hunter-gatherers declines rapidly, more than a decade before the average terminal age of 55 years. Given this, the human brain would have been a tremendous metabolic liability that must have been advantageously tempered by the early cellular and molecular changes of AD which begin to accumulate in all humans during early adulthood. Before the recent lengthening of life span, individuals in the ancestral environment died well before this metabolism reduction program resulted in clinical AD, thus there was never any selective pressure to keep adaptive changes from progressing to a maladaptive extent.
Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce ... more Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce hypometabolism and decreasing synaptic density in the hippocampus and the prefrontal cortex (PFC). This article evaluates and explores evidence supporting the hypothesis that these, and other, selective effects of prolonged stress constitute a neuroecological program that adaptively modifies behavior in mammals experiencing adverse conditions. Three complementary hypotheses are proposed: (1) chronic stress signifies that the prevailing environment is life-threatening, indicating that the animal should decrease activity in brain areas capable of inhibiting the stress axis; (2) stress signifies that the environment is unpredictable, that high-level cognition may be less effective, and that the animal should increase its reliance on defensive, procedural and instinctual behaviors mediated by lower brain centers; and (3) stress indicates that environmental events are proving difficult to systemize based on delayed associations, and thus the maintenance of contextual, task-relevant information in the PFC need not be maintained for temporally-extended periods. Humans, along with countless other species of vertebrates, have been shown to make predictive, adaptive responses to chronic stress in many systems including metabolic, cardiovascular, neuroendocrine, and even amygdalar and striatal systems. It is proposed in this article that humans and other mammals may also have an inducible, cerebrocortical response to pronounced stress that mediates a transition from time-intensive, explicit (controlled/attentional/top-down) processing of information to quick, implicit (automatic/preattentive/bottom-up) processing.
This article provides an analytical framework for how to simulate human-like thought processes wi... more This article provides an analytical framework for how to simulate human-like thought processes within a computer. It describes how attention and memory should be structured, updated, and utilized to search for associative additions to the stream of thought. The focus is on replicating the mammalian working memory system, which features two forms of persistent activity: sustained firing (preserving information on the order of seconds) and synaptic potentiation (preserving information from minutes to hours). The article uses a series of over 40 original figures to systematically demonstrate how the iterative updating of these working memory stores provides functional structure to thought and consciousness.
In an AI implementation, these two stores should be updated continuously and in an iterative fashion, meaning each state should preserve a proportion of the coactive representations from the state before it. Thus, the set of concepts in working memory will evolve gradually and incrementally over time. This makes each state a revised iteration of the preceding state and causes successive states to overlap and blend with respect to the information they contain. Transitions between states happen as persistent activity spreads activation energy throughout the hierarchical network searching long-term memory for the most appropriate representation to be added to the global workspace. The result is a chain of associatively linked intermediate states capable of advancing toward a solution or goal. Iterative updating is conceptualized here as an information processing strategy, a model of working memory, a theory of consciousness, and an algorithm for designing and programming artificial general intelligence.
It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and a... more It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and associated comorbidities is largely a product of our modern environment. Artificially high levels of sugars, fats, and processed foods, along with sedentary behavior constitute an “obesogenic” environment which makes us more susceptible to the metabolic syndrome today than our foraging ancestors were millennia ago. A number of comparative analyses relevant to the influence of behavior, diet, and nutrition on the metabolic syndrome are reviewed here, especially with regard to the developmental origins of the syndrome. It has become clear that early environmental conditions, particularly poor nutrition, have the ability to act as cues that program the phenotype in utero. It is thought that the fetus has an adaptive ability to perceive nutritional deprivation, and reprogram its metabolic systems for energy efficiency, as a predictive response to expected environmental scarcity. These metabolic alterations are thought to be beneficial in times of poor nutritional quality, but unfortunately have consistently been shown to result in adverse health outcomes and metabolic disease, when food is calorie dense and readily available. These early life changes are brought about by alterations in cellular proliferation and differentiation that are ultimately driven by neuroendocrine, cellular, and epigenetic adaptations to undernutrition. Besides the various metabolic changes, animals programmed for thrift have been shown to exhibit neurological changes resulting in hyperphagia, increased sedentariness, and volume reductions in the cerebral cortex. A great deal of evidence, including countless animal studies and a worldwide series of epidemiological investigations, has supported the close relationship between early nutritional status and susceptibility to the major risk factors (increased adiposity, hypertension, and insulin resistance) for the metabolic syndrome in later life. The perspectives originated by James Neel (the thrifty genotype hypothesis), and David Barker (the thrifty phenotype hypothesis) have remained important interpretations through which to view the nature of the genetic, structural, and adaptive facets of the programming of metabolic function. Moreover, these perspectives, and the integrative conceptualizations that they promote, have begun to provide valuable direction for research and health care.
Tourette syndrome, and the closely related spectrum of tic disorders, are inherited neuropsychiat... more Tourette syndrome, and the closely related spectrum of tic disorders, are inherited neuropsychiatric conditions characterized by the presence of repetitive and stereotyped movements. Tics are elicited by either environmental experiences or internal signals that instruct the basal ganglia to initiate automatic or procedural movements. In most vertebrates the basal ganglia encode instructions for habitually used sequences of motor movements that are essential to survival. Tic disorders may represent evolved phenotypes with a lower threshold for basal ganglia-directed actions. This may have produced a susceptibility to extraneous tics, but also produced fast-acting tactical solutions to immediate physical problems. During periods of nonstop movement, continual foraging, and sustained vigilance, it may have been advantageous to allow subcortical motor commands to intrude into ongoing motor activities. It is clear that the engrams for individual motor responses held in the basal ganglia are selected by converging cortical and subcortical inputs. This form of convergent action selection results in the selection of the most contextually reinforced actions. Today people with Tourette's have tics that seem arbitrary and inappropriate; however, this may be due to the vast discrepancies in reinforcement between the ancestral environment and the modern one. In prehistoric environments, the motor behaviors of individuals with tic disorders may have been appropriate in environmental context, and had ecological relevance in survival and self-promotion.
It is well recognized that investigation into the relationship between early life programming and... more It is well recognized that investigation into the relationship between early life programming and subsequent neurological disorders may have powerful implications for understanding the human vulnerability to psychopathology. The present article will propose that schizophrenia may be adaptively programmed by early environmental adversity permitting physiological and behavioral characteristics that would have created a fitness advantage in the ancestral environment under conditions of nutritional scarcity and severe environmental stress. This proposition will be analyzed in terms of phenotypic plasticity theory which explains how and why specific environmental stressors can alter normal gene expression resulting in an alternative phenotype that is better suited for an adverse environment. The primary neurophysiological symptoms of schizophrenia can be induced in animals through exposure to prenatal and postnatal stressors, and that schizophrenia itself is known to be associated with exposure to stress during development, supports the view that the "disorder" may represent a predictive, adaptive response to adversity. In fact, maternal malnutrition, maternal stress, multiparity, short birth interval and stress provoking postnatal events are well recognized epidemiological risk factors for schizophrenia that may represent cues for the initiation of epigenetic programming. Behavioral and physiological characteristics of schizophrenia will be analyzed and interpreted as protective in the context of environmental hardship. For instance, the hypometabolic areas of the schizophrenic brain--the hippocampus and the frontal lobes--are the same areas that are known to become adaptively hypometabolic in response to starvation, stress and variations in ecological rigor in birds and mammals. Individuals with schizophrenia are also highly genetically inclined to develop the metabolic syndrome, which is widely thought to allow developmentally deprived mammals to conserve energy under poor circumstances. It is well known that schizophrenia features an up-regulated hypothalamic-pituitary-adrenal axis and an exaggerated stress response--both alterations thought to represent predictive, adaptive responses to stress in mammals--which may have increased attentiveness to the environment and created a defensive, vigilance-based behavioral strategy. The habituation deficits characteristic of schizophrenia--which can be induced in other mammals through stress--may represent a cognitive strategy that alerts the organism to salient, potentially informative stimuli and that permits it to be more impulsive and vigilant. Inability to calm instinctual drives, ignore arousing stimuli, and inhibit transient desires are all core characteristics of the disorder, which predict social and vocational disabilities in modern times, but may have amounted to a robust, selfish strategy in prehistoric times.
This article will suggest that moderate sleep apnea may have an adaptive benefit, the reduction o... more This article will suggest that moderate sleep apnea may have an adaptive benefit, the reduction of nocturnal, respiratory heat loss, that may have caused it to be selected for despite the associated disadvantages. Sleep apnea is caused by the collapse of the throat, specifically the pharyngeal airway, during sleep and can result in discomfort and hypoxia. The large size of the fleshy structures in the pharynx and hypotonicity of the pharyngeal musculature are what cause humans, and many other species of mammals, to be susceptible to apnea. There are many functional and anatomical parallels between sleep apnea and a well known, thermoregulatory response that minimizes respiratory cooling in the lower airways known as reflex bronchoconstriction. Bronchoconstriction involves the constriction of the inner airways, the bronchioles, in response to cold air, a reaction that acts to warm inspired air before it makes contact with the more sensitive lower airways and alveoli. Because air is colder at night and body temperature drops severely during sleep, sleep apnea may represent a similar protective, thermoregulatory adaptation. When the pharynx is collapsed, the diameter of the pharyngeal airway decreases, allowing increased intermolecular collisions between inspired air and the epithelial walls of the upper airway. An increase in the number of collisions facilitates the transference of both warmth and humidity to inspired air before it reaches the more sensitive lower airway resulting in the maintenance of internal, core temperature and alveolar heat retention. In fact, sleep apnea can be conceptualized as a functional reversal of the thermoregulatory process of panting, where the pharynx is highly dilated instead of collapsed. Given the disorder associated with sleep apnea, the absence of a disease state secondary to surgical correction, the fact that the disorder is exclusive to warm-blooded animals, the high proclivity for collapse documented in pregnant mothers, and the functional similarities between collapse and reflex bronchoconstriction, it appears that the phenomenon may represent an evolutionary trade-off that helped to minimize respiratory cooling.
This paper will suggest that the Down syndrome phenotype would have been well suited, physiologic... more This paper will suggest that the Down syndrome phenotype would have been well suited, physiologically, for a deprived environment and that it may represent a predictive, adaptive response to severe maternal deprivation. A trisomy of the 21st chromosome, prior to, or at conception is responsible for Down syndrome and is known to increase in incidence with advanced maternal age. One out of 11 mothers over the age of 50 conceives a Down syndrome baby, compared to one in one thousand at age 30. This article emphasizes that an older mother is more likely to die before she is able to provide the parental investment necessary to produce an ecologically selfsufficient offspring. Prolonged maternal investment is known to be essential for hunter-gatherers to master the skill intensive food procurement techniques that they will need in order to become independent of their mothers. Because Down syndrome individuals are much more likely to be born to older mothers, they must have been routinely deprived of maternal investment in the human environment of evolutionary adaptedness. This consistent paring of maternal deprivation to trisomy 21 conceptions, over time, may have caused natural selection to favor genes responsible for the energy conserving traits seen in modern day Down syndrome. These traits include muscle hypotonia, decreased cerebral metabolism, decreased hippocampal volume, a strong propensity for obesity and growth hormone and thyroid hormone paucity. Such a "thrifty phenotype" may have allowed Down syndrome individuals to become independent of their mothers at a far earlier age and allowed them to forgo the skill intensive ecological niche that non-trisomic humans are phenotypically suited for in order to take up a less cognitively and physically rigorous one.
This article will propose that humans have an adaptive vulnerability to certain forms of mental r... more This article will propose that humans have an adaptive vulnerability to certain forms of mental retardation, specifically, neuropathological disorders that cause decreased energy expenditure in the hippocampus and the cerebral cortex. This hypothesis will be analyzed in terms of the thrifty phenotype paradigm according to which adverse prenatal events can cause differential gene expression resulting in a phenotype that is better suited, metabolically, for a deprived environment. For example, a malnourished mother has an increased propensity to give birth to offspring that feature a ''thrifty phenotype'' which permits highly efficient calorie utilization, increased fat deposition and a sedentary nature. This article interprets several prenatal occurrences, including maternal malnourishment, low birth weight, multiparity, short birth interval, advanced maternal age and maternal stresswhich are currently identified by the epidemiological literature as risk factors for neuropathology-to be environmental cues that communicate to the fetus that, because it will be neglected of maternal investment, developing a metabolically conservative brain will be the most effective ecological strategy. Success in hunting and foraging in mammals, primates and especially humans is known to be dependent on prolonged maternal investment. Low levels of maternal care are known to result in low survivorship of offspring, largely because the offspring are forced to subsist using simple, low-yield foraging strategies. A predictive, adaptive response, marked by cerebral hypometabolism, may produce a level of metabolic conservancy that mitigates the risks associated with low levels of maternal care. This article will suggest that certain, human neuropathological phenotypes would have been well suited for an ecological niche that closely resembled the less skill-intensive niche of our less encephalized, primate ancestors. The forms of congenital neuropathology discussed in this article do not cause damage to vital homeostatic systems; most simply decrease the size and energy expenditure of the cerebral cortex and the hippocampus, the two structures known to show plasticity during changes in ecological rigor in vertebrates. Also, many disorders that present comorbidly with neuropathology, such as tendency toward obesity, decrement in anabolic hormones, hypotonic musculature, up-regulation of the hypothalamic-pituitary-adrenal axis, and decreased thyroid output are associated with energy conservancy and the thrifty phenotype, further implicating neuropathology in an ecological strategy.
This article presents an artificial intelligence (AI) architecture intended to simulate the human... more This article presents an artificial intelligence (AI) architecture intended to simulate the human working memory system as well as the manner in which it is updated iteratively. It features several interconnected neural networks designed to emulate the specialized modules of the cerebral cortex. These are structured hierarchically and integrated into a global workspace. They are capable of temporarily maintaining high-level patterns akin to the psychological items maintained in working memory. This maintenance is made possible by persistent neural activity in the form of two modalities: sustained neural firing (resulting in a focus of attention) and synaptic potentiation (resulting in a short-term store). This persistent activity is updated iteratively resulting in incremental changes to the content of the working memory system. As the content stored in working memory gradually evolves, successive states overlap and are continuous with one another. The present article will explore how this architecture can lead to gradual shift in the distribution of coactive representations, ultimately leading to mental continuity between processing states, and thus to human-like cognition.
The term state-spanning coactivity (SSC) is introduced to refer to shared content between success... more The term state-spanning coactivity (SSC) is introduced to refer to shared content between successive brain states. • SSC is made possible by sustained firing, binding, and recurrent processing. • Sustained activity ensures that consecutive topographic maps are interrelated. • SSC also permits continuous, algorithmic, and progressive alterations to mental imagery. • Incremental change in SSC (icSSC) allows the continuity necessary for updating, modeling, and systemization.
This book examines the foundations of personal belief by conducting a review of classical and con... more This book examines the foundations of personal belief by conducting a review of classical and contemporary thought about beliefs, by experimenting with new and innovative ways to conceptualize beliefs and by presenting new evidence about beliefs from empirical studies. Beliefs, although often vaguely defined in discourse, can be conceptualized in many different ways: as associative memories; as coactivations between multiple neural assemblies; as functional cognitive instruments; as self- propagating entities that parasitize minds; as the firings of a certainty module in the brain; as placeholders for self-identity; or as means by which to make sense out of the world. This book explores each of these very different facets of belief in an endeavor to explicate the origins and dynamics of believing. Concepts that are considered include personal epistemology, delusional thinking, unconscious processes, the neurobiology of belief, the ontology of belief, and the evolutionary pressures on belief accuracy. The viewpoints garnered, although they come from disparate fields, interface in provocative ways and taken together, paint a rich portrait of the mechanics of belief.
This article reviews etiological and comparative evidence supporting the hypothesis that some gen... more This article reviews etiological and comparative evidence supporting the hypothesis that some genes associated with the autism spectrum were naturally selected and represent the adaptive benefits of being cognitively suited for solitary foraging. People on the autism spectrum are conceptualized here as ecologically competent individuals that could have been adept at learning and implementing hunting and gathering skills in the ancestral environment. Upon independence from their mothers, individuals on the autism spectrum may have been psychologically predisposed toward a different life-history strategy, common among mammals and even some primates, to hunt and gather primarily on their own. Many of the behavioral and cognitive tendencies that autistic individuals exhibit are viewed here as adaptations that would have complemented a solitary lifestyle. For example, the obsessive, repetitive and systemizing tendencies in autism, which can be mistakenly applied toward activities such as block stacking today, may have been focused by hunger and thirst toward successful food procurement in the ancestral past. Both solitary mammals and autistic individuals are low on measures of gregariousness, socialization, direct gazing, eye contact, facial expression, facial recognition, emotional engagement, affiliative need and other social behaviors. The evolution of the neurological tendencies in solitary species that predispose them toward being introverted and reclusive may hold important clues for the evolution of the autism spectrum and the natural selection of autism genes. Solitary animals are thought to eschew unnecessary social contact as part of a foraging strategy often due to scarcity and wide dispersal of food in their native environments. It is thought that the human ancestral environment was often nutritionally sparse as well, and this may have driven human parties to periodically disband. Inconsistencies in group size must have led to inconsistencies in the manner in which natural selection fashioned the social minds of humans, which in turn may well be responsible for the large variation in social abilities seen in human populations. This article emphasizes that individuals on the autism spectrum may have only been partially solitary, that natural selection may have only favored subclinical autistic traits and that the most severe cases of autism may be due to assortative mating.
This article presents an artificial intelligence (AI) architecture intended to simulate the human... more This article presents an artificial intelligence (AI) architecture intended to simulate the human working memory system as well as the manner in which it is updated iteratively. It features several interconnected neural networks designed to emulate the specialized modules of the cerebral cortex. These are structured hierarchically and integrated into a global workspace. They are capable of temporarily maintaining high-level patterns akin to the psychological items maintained in working memory. This maintenance is made possible by persistent neural activity in the form of two modalities: sustained neural firing (resulting in a focus of attention) and synaptic potentiation (resulting in a short-term store). This persistent activity is updated iteratively resulting in incremental changes to the content of the working memory system. As the content stored in working memory gradually evolves, successive states overlap and are continuous with one another. The present article will explore how this architecture can lead to gradual shift in the distribution of coactive representations, ultimately leading to mental continuity between processing states, and thus to human-like cognition.
This opinion article explores how sustained neural firing in association areas allows high-order ... more This opinion article explores how sustained neural firing in association areas allows high-order mental representations to be coactivated over multiple perception-action cycles, permitting sequential mental states to share overlapping content and thus be recursively interrelated. The term "state-spanning coactivity" (SSC) is introduced to refer to neural nodes that remain coactive as a group over a given period of time. SSC ensures that contextual groupings of goal or motor-relevant representations will demonstrate continuous activity over a delay period. It also allows potentially related representations to accumulate and coactivate despite delays between their initial appearances. The nodes that demonstrate SSC are a subset of the active representations from the previous state, and can act as referents to which newly introduced representations of succeeding states relate. Coactive nodes pool their spreading activity, converging on and activating new nodes, adding these t...
Individuals with schizophrenia are at a high risk of developing life-shortening illnesses and are... more Individuals with schizophrenia are at a high risk of developing life-shortening illnesses and are especially prone to developing metabolic diseases. Epidemiological evidence has demonstrated that schizophrenia is closely associated with the metabolic syndrome and its associated disorders, including type 2 diabetes mellitus, cardiovascular disease, dyslipidemia, visceral fat distribution, and hypertension. This association has been attributed to behavioral factors seen in patients with schizophrenia like poor diet, increased food intake, increased dietary fat content, lack of exercise, and reduced physical activity but there are clearly other mediating factors. Specific features of the metabolic syndrome are known to be exacerbated by severe stress and elevated levels of cortisol, elements common in schizophrenia. The antipsychotic medications widely prescribed in schizophrenia, especially the atypical antipsychotics, have been implicated in the onset and worsening of metabolic symptoms. There is also evidence pointing towards the fact that schizophrenia and the metabolic syndrome present comorbidly because of a shared genetic basis. The public health significance of these associations is clear and provides impetus for mental health professionals to become more responsible for identifying, treating, and monitoring the physical symptoms of schizophrenia in addition to the psychiatric ones. Unfortunately, health care practitioners may not place enough emphasis on the treatment of metabolic disorders in this population because of low awareness and past ambiguity of findings.
It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and a... more It is clear that the modern epidemic of obesity, cardiovascular disease, diabetes mellitus, and associated comorbidities is largely a product of our modern environment. Artificially high levels of sugars, fats, and processed foods, along with sedentary behavior constitute an “obesogenic” environment which makes us more susceptible to the metabolic syndrome today than our foraging ancestors were millennia ago. A number of comparative analyses relevant to the influence of behavior, diet, and nutrition on the metabolic syndrome are reviewed here, especially with regard to the developmental origins of the syndrome. It has become clear that early environmental conditions, particularly poor nutrition, have the ability to act as cues that program the phenotype in utero. It is thought that the fetus has an adaptive ability to perceive nutritional deprivation, and reprogram its metabolic systems for energy efficiency, as a predictive response to expected environmental scarcity. These metabolic alterations are thought to be beneficial in times of poor nutritional quality, but unfortunately have consistently been shown to result in adverse health outcomes and metabolic disease, when food is calorie dense and readily available. These early life changes are brought about by alterations in cellular proliferation and differentiation that are ultimately driven by neuroendocrine, cellular, and epigenetic adaptations to undernutrition. Besides the various metabolic changes, animals programmed for thrift have been shown to exhibit neurological changes resulting in hyperphagia, increased sedentariness, and volume reductions in the cerebral cortex. A great deal of evidence, including countless animal studies and a worldwide series of epidemiological investigations, has supported the close relationship between early nutritional status and susceptibility to the major risk factors (increased adiposity, hypertension, and insulin resistance) for the metabolic syndrome in later life. The perspectives originated by James Neel (the thrifty genotype hypothesis), and David Barker (the thrifty phenotype hypothesis) have remained important interpretations through which to view the nature of the genetic, structural, and adaptive facets of the programming of metabolic function. Moreover, these perspectives, and the integrative conceptualizations that they promote, have begun to provide valuable direction for research and health care.
This article will propose that humans have an adaptive vulnerability to certain forms of mental r... more This article will propose that humans have an adaptive vulnerability to certain forms of mental retardation, specifically, neuropathological disorders that cause decreased energy expenditure in the hippocampus and the cerebral cortex. This hypothesis will be analyzed in terms of the thrifty phenotype paradigm according to which adverse prenatal events can cause differential gene expression resulting in a phenotype that is better suited, metabolically, for a deprived environment. For example, a malnourished mother has an increased propensity to give birth to offspring that feature a ''thrifty phenotype'' which permits highly efficient calorie utilization, increased fat deposition and a sedentary nature. This article interprets several prenatal occurrences, including maternal malnourishment, low birth weight, multiparity, short birth interval, advanced maternal age and maternal stresswhich are currently identified by the epidemiological literature as risk factors for neuropathology-to be environmental cues that communicate to the fetus that, because it will be neglected of maternal investment, developing a metabolically conservative brain will be the most effective ecological strategy. Success in hunting and foraging in mammals, primates and especially humans is known to be dependent on prolonged maternal investment. Low levels of maternal care are known to result in low survivorship of offspring, largely because the offspring are forced to subsist using simple, low-yield foraging strategies. A predictive, adaptive response, marked by cerebral hypometabolism, may produce a level of metabolic conservancy that mitigates the risks associated with low levels of maternal care. This article will suggest that certain, human neuropathological phenotypes would have been well suited for an ecological niche that closely resembled the less skill-intensive niche of our less encephalized, primate ancestors. The forms of congenital neuropathology discussed in this article do not cause damage to vital homeostatic systems; most simply decrease the size and energy expenditure of the cerebral cortex and the hippocampus, the two structures known to show plasticity during changes in ecological rigor in vertebrates. Also, many disorders that present comorbidly with neuropathology, such as tendency toward obesity, decrement in anabolic hormones, hypotonic musculature, up-regulation of the hypothalamic-pituitary-adrenal axis, and decreased thyroid output are associated with energy conservancy and the thrifty phenotype, further implicating neuropathology in an ecological strategy.
Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce ... more Prolonged psychological stress and accompanying elevations in blood cortisol are known to induce hypometabolism and decreasing synaptic density in the hippocampus and the prefrontal cortex (PFC). This article evaluates and explores evidence supporting the hypothesis that these, and other, selective effects of prolonged stress constitute a neuroecological program that adaptively modifies behavior in mammals experiencing adverse conditions. Three complementary hypotheses are proposed: (1) chronic stress signifies that the prevailing environment is life-threatening, indicating that the animal should decrease activity in brain areas capable of inhibiting the stress axis; (2) stress signifies that the environment is unpredictable, that high-level cognition may be less effective, and that the animal should increase its reliance on defensive, procedural and instinctual behaviors mediated by lower brain centers; and (3) stress indicates that environmental events are proving difficult to sys...
This opinion article explores how sustained neural firing in association areas allows high-order ... more This opinion article explores how sustained neural firing in association areas allows high-order mental representations to be coactivated over multiple perception-action cycles, permitting sequential mental states to share overlapping content and thus be recursively interrelated. The term "state-spanning coactivity" (SSC) is introduced to refer to neural nodes that remain coactive as a group over a given period of time. SSC ensures that contextual groupings of goal or motor-relevant representations will demonstrate continuous activity over a delay period. It also allows potentially related representations to accumulate and coactivate despite delays between their initial appearances. The nodes that demonstrate SSC are a subset of the active representations from the previous state, and can act as referents to which newly introduced representations of succeeding states relate. Coactive nodes pool their spreading activity, converging on and activating new nodes, adding these t...
Did you know the most dominant apes and monkeys are usually the kindest? They share the most food... more Did you know the most dominant apes and monkeys are usually the kindest? They share the most food, groom others more often, break up fights, are slow to anger, and breathe in a relaxed manner. Those on the bottom of the social hierarchy are the opposite. They are stingy, combative, irritable, anxious, depressed, and they breathe shallowly. It is not easy for a submissive primate to become dominant. They have mindsets, mannerisms, and muscle tension that keep them from escaping their subordinate social strategy and the chronic stress it produces.
All of this generalizes to people. If you want to be free of negative emotion, you need to rehabilitate physical trauma in your breath, eyes, face, voice, heart, gut, spine, and brain. Program Peace will coach you to do precisely this by first retraining your breathing pattern, and then walking you through dozens of innovative and effective self-care exercises. After creating new mindsets and mannerisms, and learning to reinvigorate muscles you never knew you had, you will find yourself more confident, healthier, kinder, and reprogrammed for peace.
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Papers by Jared Reser
In an AI implementation, these two stores should be updated continuously and in an iterative fashion, meaning each state should preserve a proportion of the coactive representations from the state before it. Thus, the set of concepts in working memory will evolve gradually and incrementally over time. This makes each state a revised iteration of the preceding state and causes successive states to overlap and blend with respect to the information they contain. Transitions between states happen as persistent activity spreads activation energy throughout the hierarchical network searching long-term memory for the most appropriate representation to be added to the global workspace. The result is a chain of associatively linked intermediate states capable of advancing toward a solution or goal. Iterative updating is conceptualized here as an information processing strategy, a model of working memory, a theory of consciousness, and an algorithm for designing and programming artificial general intelligence.
In an AI implementation, these two stores should be updated continuously and in an iterative fashion, meaning each state should preserve a proportion of the coactive representations from the state before it. Thus, the set of concepts in working memory will evolve gradually and incrementally over time. This makes each state a revised iteration of the preceding state and causes successive states to overlap and blend with respect to the information they contain. Transitions between states happen as persistent activity spreads activation energy throughout the hierarchical network searching long-term memory for the most appropriate representation to be added to the global workspace. The result is a chain of associatively linked intermediate states capable of advancing toward a solution or goal. Iterative updating is conceptualized here as an information processing strategy, a model of working memory, a theory of consciousness, and an algorithm for designing and programming artificial general intelligence.
All of this generalizes to people. If you want to be free of negative emotion, you need to rehabilitate physical trauma in your breath, eyes, face, voice, heart, gut, spine, and brain. Program Peace will coach you to do precisely this by first retraining your breathing pattern, and then walking you through dozens of innovative and effective self-care exercises. After creating new mindsets and mannerisms, and learning to reinvigorate muscles you never knew you had, you will find yourself more confident, healthier, kinder, and reprogrammed for peace.