Papers by Aaron Blaisdell
In our daily life, we visually perceive an external space and effortlessly navigate through it. A... more In our daily life, we visually perceive an external space and effortlessly navigate through it. Although visual stimulation reaches the 2D retinas in the egocentric frame, our brains appear to reconstruct and maintain external allocentric 3D space regardless of constantly moving eyes, head, and body. How can the 2D egocentric retinotopy be converted to the meaningful allocentric 3D space so promptly and reliably? By applying the new concept of Neural Holographic Tomography (NHT) with Holographic Ring Attractor Lattice (HAL) developed in Part II, this Part III directly solves the above mysteries, especially the following three essential questions: 1) How are saccades compensated to establish stable vision? 2) How is 3D allocentric space visually perceived with depth? 3) How are semantic shapes recognized in a scale-invariant and rotation-invariant manner? Fundamentally, our vision acts on the frequency-time domain by using alpha brainwaves that holographically project a predicted 3D image in front of us, very much like a 3D projection mapping onto an empty space. This procedure satisfies the basic principle of MePMoS in Part I, which is supported both causally and locally.
Human vision has a remarkable ability to recognize complex 3D objects such as faces that appear a... more Human vision has a remarkable ability to recognize complex 3D objects such as faces that appear at any size and 3D orientations at any 3D location. If we initially memorize a face only with a normalized size upfront at the object center, the direct comparison between the one-sized memory and an incoming new image would demand tremendous mental frame translations in 7D. How can we perform such a demanding task so promptly as we experience it in our daily lives?This paper specifically addresses the recognition of human faces with arbitrary 3D orientation in the [Roll, Yaw, Pitch] axes. According to our new model ofNHT(Neural Holography Tomography), space is represented by time utilizing the phase of the alpha brainwave. This principle should be applicable to any mental rotation in 3D; thus, it predicts that extra time is required to perceive a rotated face to revolve it back to upright by the constant-speed alpha wave.To assess this hypothesis, we designed a reaction time (RT) experim...
International Journal of Comparative Psychology, 2019
Deeply rooted within the history of experimental psychology is the search for general laws of lea... more Deeply rooted within the history of experimental psychology is the search for general laws of learning that hold across tasks and species. Central to this enterprise has been the notion of equipotentiality; that any two events have the same likelihood of being associated with one another as any other pair of events. Much work, generally summarized as ‘biological constraints on learning,’ has challenged this view, and demonstrates pre-existing relations between cues and outcomes, based on genes and prior experience, that influence potential associability. Learning theorists and comparative psychologists have thus recognized the need to consider how the evolutionary history as well as prior experience of the organism being studied influences its ability to learn about and navigate its environment. We suggest that current models of human memory, and human memory research in general, lack sufficient consideration of how human evolution has shaped human memory systems. We review several ...
Biological Reviews, 2020
ABSTRACTThe cognitive map has been taken as the standard model for how agents infer the most effi... more ABSTRACTThe cognitive map has been taken as the standard model for how agents infer the most efficient route to a goal location. Alternatively, path integration – maintaining a homing vector during navigation – constitutes a primitive and presumably less‐flexible strategy than cognitive mapping because path integration relies primarily on vestibular stimuli and pace counting. The historical debate as to whether complex spatial navigation is ruled by associative learning or cognitive map mechanisms has been challenged by experimental difficulties in successfully neutralizing path integration. To our knowledge, there are only three studies that have succeeded in resolving this issue, all showing clear evidence of novel route taking, a behaviour outside the scope of traditional associative learning accounts. Nevertheless, there is no mechanistic explanation as to how animals perform novel route taking. We propose here a new model of spatial learning that combines path integration with ...
Diets consisting of refined foods (REF) are associated with poor physical (e.g., obesity and diab... more Diets consisting of refined foods (REF) are associated with poor physical (e.g., obesity and diabetes) and mental (e.g., depression) health and impaired cognition. Few animal studies have explored the causal links between diet processing and health. Instead, most studies focus on the role of macronutrients, especially carbohydrate and fat concurrently with how processed are the ingredients. We previously showed that a REF low fat diet (LFD) caused greater adiposity and impaired motivation compared to an unrefined control (CON) diet consisting of similar macronutrient ratios (Blaisdell et al., 2014). Here we test the hypothesis that the same REF LFD adversely affects attentional processes and behavioral control relative to the CON diet. Rats with ad libitum access to the REF diet for two months gained greater adiposity than rats consuming the CON diet. Rats then completed training on a vigilance task involving pressing the correct lever signaled by a brief visual cue whose onset varied across trials. A REF diet reduced accuracy when there was a delay between the start of the trial and cue onset. Poorer accuracy was due to increased premature responses, reflecting impulsivity, and omissions, indicating an inability to sustain attention. These results corroborate the links between consumption of refined foods, obesity, and poor cognition in humans. We discuss the possible causal models that underlie this link.
Acta Psychologica, 2013
Prior research, using two-and three-dimensional environments, has found that when both human and ... more Prior research, using two-and three-dimensional environments, has found that when both human and nonhuman animals independently acquire two associations between landmarks with a common landmark (e.g., LM1-LM2 and LM2-LM3), each with its own spatial relationship, they behave as if the two unique LMs have a known spatial relationship despite their never having been paired. Seemingly, they have integrated the two associations to create a third association with its own spatial relationship (LM1-LM3). Using sensory preconditioning (Experiment 1) and second-order conditioning (Experiment 2) procedures, we found that human participants integrated information about the boundaries of pathways to locate a goal within a three-dimensional virtual environment in the absence of any relevant landmarks. Spatial integration depended on the participant experiencing a common boundary feature with which to link the pathways. These results suggest that the principles of associative learning also apply to the boundaries of an environment.
A predominant trend throughout the evolution of animals has been an increase in neural complexity... more A predominant trend throughout the evolution of animals has been an increase in neural complexity. Comparative cognition research investigates cognition in diverse species to better understand the evolution of cognition. I present research from my own lab involving rats, pigeons, and hermit crabs, that illustrates some basic cognitive processes found in the Animal Kingdom. I discuss some of my work on perception, attention, and simple learning in the terrestrial Caribbean hermit crab; associative learning, memory, and spatial cognition in the pigeon; and temporal cognition, causal reasoning, and rational inferences in the rat. An overarching theme emerges that more complex processes build upon simpler ones, such as learning and memory building on perception, and rational inference building on associative learning and memory. I close with a discussion of the future of research in comparative cognition.
Journal of Experimental Psychology: Animal Behavior Processes, 1998
Behavioural Processes, 2012
There is much interest in studying animal personalities but considerable debate as to how to defi... more There is much interest in studying animal personalities but considerable debate as to how to define and evaluate them. We assessed the utility of one proposed framework while studying personality in terrestrial hermit crabs (Coenobita clypeatus). We recorded the latency of individuals to emerge from their shells over multiple trials in four unique manipulations. We used the specific testing situations within these manipulations to define two temperament categories (shyness-boldness and exploration-avoidance). Our results identified individual behavioral consistency (i.e., personality) across repeated trials of the same situations, within both categories. Additionally, we found correlations between behaviors across contexts (traits) that suggested that the crabs had behavioral syndromes. While we found some correlations between behaviors that are supposed to measure the same temperament trait, these correlations were not inevitable. Furthermore, a principal component analysis (PCA) of our data revealed new relationships between behaviors and provided the foundation for an alternate interpretation: measured behaviors may be situation-specific, and may not reflect general personality traits at all. These results suggest that more attention must be placed on how we infer personalities from standardized methods, and that we must be careful to not force our data to fit our frameworks.
Science, 2006
Empirical research with nonhuman primates appears to support the view that causal reasoning is a ... more Empirical research with nonhuman primates appears to support the view that causal reasoning is a key cognitive faculty that divides humans from animals. The claim is that animals approximate causal learning using associative processes. The present results cast doubt on that conclusion. Rats made causal inferences in a basic task that taps into core features of causal reasoning without requiring complex physical knowledge. They derived predictions of the outcomes of interventions after passive observational learning of different kinds of causal models. These competencies cannot be explained by current associative theories but are consistent with causal Bayes net theories.
Journal of experimental psychology. General, 2008
A. P. Blaisdell, K. Sawa, K. J. Leising, and M. R. Waldmann (2006) reported evidence for causal r... more A. P. Blaisdell, K. Sawa, K. J. Leising, and M. R. Waldmann (2006) reported evidence for causal reasoning in rats. After learning through Pavlovian observation that Event A (a light) was a common cause of Events X (an auditory stimulus) and F (food), rats predicted F in the test phase when they observed Event X as a cue but not when they generated X by a lever press. Whereas associative accounts predict associations between X and F regardless of whether X is observed or generated by an action, causal-model theory predicts that the intervention at test should lead to discounting of A, the regular cause of X. The authors report further tests of causal-model theory. One key prediction is that full discounting should be observed only when the alternative cause is viewed as deterministic and independent of other events, 2 hallmark features of actions but not necessarily of arbitrary events. Consequently, the authors observed discounting with only interventions but not other observable ev...
The probabilistic mind. Prospects for Bayesian cognitive science, Jun 2, 2008
We investigated extinction and spontaneous recovery of spatial associations using a landmark-base... more We investigated extinction and spontaneous recovery of spatial associations using a landmark-based appetitive search task in a touchscreen preparation with pigeons. Four visual landmarks (A, B, C, and D) were separately established as signals of a hidden reinforced target among an 8 X 7 array of potential
target locations. The target was located above landmarks (LM) A and C and below B and D. After conditioning, A and B were extinguished. Responding to A and C was assessed on probe tests 2 days following extinction, whereas, B and D were tested 14 days after extinction. We observed spontaneous recovery from spatial extinction following a 14-day, but not a 2-day, postextinction retention interval. Furthermore, by plotting the spatial distribution of responding across the X and Y axes during testing, we found that spontaneous recovery of responding to the target in our task was due to enhanced spatial control (i.e., a change in the overall distribution of responses) following the long delay to testing. These results add spatial extinction and spontaneous recovery to the list of findings supporting the assertion that extinction involves new learning that attenuates the originally acquired response, and that original learning of the spatial relationship between paired events survives extinction.
Hermit crabs hide into shells when confronted with potential dangers, including images presented ... more Hermit crabs hide into shells when confronted with potential dangers, including images presented on a monitor. We do not know, however, what hermit crabs can see and how they perceive different objects.We examined the hiding response of the Caribbean hermit crab (Coenobita clypeatus) to various stimuli presented on a monitor in seven experiments to explore whether crabs could discriminate different properties of a threatening digital image, including color, brightness, contrast, shape and orientation. We found crabs responded differently to expanding circles presented in wavelengths of light corresponding to what humans see as red, blue, and green. “Blue” stimuli elicited the strongest hiding response (Experiments 1, 2, & 7). “Blue” was also more effective than a gray stimulus of similar brightness (Experiment 3). Hermit crabs were sensitive to the amount of contrast between a stimulus and its background rather than absolute brightness of the stimulus (Experiment 4). Moreover, we did not find evidence that crabs could discriminate orientation (Experiment 6), and mixed evidence that they could discriminate stimulus shape(Experiments 5 & 7). These results suggest that the Caribbean hermit crab is sensitive to color features,but not spatial features, of a threatening object presented on a computer screen. This is the first study to use the hiding response of the hermit crab to examine its visual ability, and demonstrates that the hiding response provides a useful behavioral approach with which to study learning and discrimination in the hermit crab.
Children love to play. Why do they find such a frivolous activity so pleasurable and desirable? P... more Children love to play. Why do they find such a frivolous activity so pleasurable and desirable? Perhaps it is not frivolous, but instead is an adaptation designed to guide proper cognitive development in human children. To understand why, I marshal evidence from different fields to build a case for play as a central behavioral mechanism of human brain and cognitive development. I start with a discussion of human evolution, focusing on the evolution of human physiology, tool-use, the human brain, and life-history strategy, and development, and how these are all connected as an adaptive suite. The anthropological and developmental evidence suggests the existence of an extended childhood adapted to establish the skills, knowledge, and understanding necessary to become a successful hunter-gatherer. I also compare human and chimpanzee brain development, and how brain-specific genes evolved uniquely in humans to foster human brain development. I conclude with the evidence from developmental psychology that even contemporary, first-world children are born with the drive to learn and develop intellectually through play. In this framework, human play can be viewed as an adaptation that guides human brain development to produce curious, intelligent and well-adjusted adults. I close by speculating on the possibility that barriers to or constraints on play may hamper intellectual and cognitive development. I focus on the important concept of developmental decanlization as a mechanism of evolutionary mismatch. I argue that more empirical study is needed to better understand the importance of play compared to other forms of education for optimal intellectual and cognitive development.
Abstract The goal of three experiments was to study whether rats are aware of the difference betw... more Abstract The goal of three experiments was to study whether rats are aware of the difference between absence of events and lack of evidence. We used a Pavlovian extinction paradigm in which lights consistently signaling sucrose were suddenly paired with the absence of sucrose. The crucial manipulation involved the absent outcomes in the extinction phase. Whereas in the Cover conditions, access to the drinking receptacle was blocked by a metal plate, in the No Cover conditions, the drinking receptacle was accessible.
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Papers by Aaron Blaisdell
target locations. The target was located above landmarks (LM) A and C and below B and D. After conditioning, A and B were extinguished. Responding to A and C was assessed on probe tests 2 days following extinction, whereas, B and D were tested 14 days after extinction. We observed spontaneous recovery from spatial extinction following a 14-day, but not a 2-day, postextinction retention interval. Furthermore, by plotting the spatial distribution of responding across the X and Y axes during testing, we found that spontaneous recovery of responding to the target in our task was due to enhanced spatial control (i.e., a change in the overall distribution of responses) following the long delay to testing. These results add spatial extinction and spontaneous recovery to the list of findings supporting the assertion that extinction involves new learning that attenuates the originally acquired response, and that original learning of the spatial relationship between paired events survives extinction.
target locations. The target was located above landmarks (LM) A and C and below B and D. After conditioning, A and B were extinguished. Responding to A and C was assessed on probe tests 2 days following extinction, whereas, B and D were tested 14 days after extinction. We observed spontaneous recovery from spatial extinction following a 14-day, but not a 2-day, postextinction retention interval. Furthermore, by plotting the spatial distribution of responding across the X and Y axes during testing, we found that spontaneous recovery of responding to the target in our task was due to enhanced spatial control (i.e., a change in the overall distribution of responses) following the long delay to testing. These results add spatial extinction and spontaneous recovery to the list of findings supporting the assertion that extinction involves new learning that attenuates the originally acquired response, and that original learning of the spatial relationship between paired events survives extinction.