OBJECTIVE Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also... more OBJECTIVE Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also be sensitive to chronic effects of mild traumatic brain injury (mTBI) in mid-life. In addition to mTBI history, other clinical factors may also influence ERP measures of brain function. This study's objective was to evaluate the relationship between mTBI history, auditory ERP metrics, and common comorbidities. METHODS ERPs elicited during an auditory target detection task, psychological symptoms, and hearing sensitivity were collected in 152 combat-exposed veterans and service members, as part of a prospective observational cohort study. Participants, with an average age of 43.6 years, were grouped according to positive (n = 110) or negative (n = 42) mTBI history. Positive histories were subcategorized into repetitive mTBI (3 + ) (n = 40) or non-repetitive (1-2) (n = 70). RESULTS Positive history of mTBI was associated with reduced N200 amplitude to targets and novel distractors. In participants with repetitive mTBI compared to non-repetitive and no mTBI, P50 was larger in response to nontargets and N100 was smaller in response to nontargets and targets. Changes in N200 were mediated by depression and anxiety symptoms and hearing loss, with no evidence of a supplementary direct mTBI pathway. CONCLUSIONS Auditory brain function differed between the positive and negative mTBI groups, especially for repetitive injury, which implicated more basic, early auditory processing than did any mTBI exposure. Symptoms of internalizing psychopathology (depression and anxiety) and hearing loss are implicated in mTBI's diminished brain responses to behaviorally relevant and novel stimuli. SIGNIFICANCE A mid-life neurologic vulnerability conferred by mTBI, particularly repetitive mTBI, may be detectable using auditory brain potentials, and so auditory ERPs are a target for study of dementia risk in this population.
... The relationship between phasic decelera-tion and RT, reported by a number of investi-gators ... more ... The relationship between phasic decelera-tion and RT, reported by a number of investi-gators (eg, Connor & Lang, 1969; Coquery & Lacey, 1966; Lacey, 1967; Lacey & Lacey, 1964; Obrist et al., 1969; Obrist, Webb, Sut-terer, & Howard, 1970), failed to receive sup-port from ...
The application of the P300 component of the event-related brain potential to the study of attent... more The application of the P300 component of the event-related brain potential to the study of attentional impairment in schizophrenia is discussed, and two recent studies are described. In one, the relative effects on P300 of stimulus modality and probability were evaluated. The data showed that the P300 is smaller in schizophrenic patients relative to normal controls for low-probability auditory stimuli. Next is described a preliminary report that evaluated whether this P300 reduction reflects a core deficit (trait marker) or clinical symptomatology (state marker). To pursue this question, a group of schizophrenic patients was studied on and off neuroleptic medication. The data showed that improvement in clinical state was highly correlated with increased visual P300 but was uncorrelated with auditory P300. These findings suggest that P300 elicited in the visual modality has the characteristics of a state marker of schizophrenia. In contrast, auditory P300 remains a candidate for a vulnerability trait marker of schizophrenia. The core deficit in schizophrenia thus appears to involve the auditory informationprocessing system, whereas fluctuations in clinical state may be reflected in the visual processing system.
The latency of the P300 component of the event-related brain potential plays a unique role in men... more The latency of the P300 component of the event-related brain potential plays a unique role in mental chronometry. This is illustrated by presenting data from two experiments that addressed the following issues in infonnation processing: a) the locus ofthe effect of stimulus probability on choice reaction time, mid b) the locus of interference in performance on the Stroop color-word test. Using P300 latency to index stimulusevaluation time, it is shown in the first experiment that both stimulus and response processing are affected by stimulus probability. The results suggest that more probable. ev.entsareJdentifiedJ_r-an effect which is reflected in decreases in both P300 and response latency-and that the responses to them are emitted more rapidly-an effect which is reflected in reaction time only. In a second experiment. using the Stroop task, response time was found to vary with the congruence between the stimulus word and the color in which it was printed. However, the duration of stimulus processing, as indexed by P300 latency, remained constant. These results indicate that response competition is the primary source of Stroop interference. It is concluded that P300 latency can be viewed as an important addition to the set of dependent variables available to study human information processing.
Light therapy in patients with seasonal affective disorder has been reported to enhance visual P3... more Light therapy in patients with seasonal affective disorder has been reported to enhance visual P300 amplitude. This findings raises the possibility that variations in P300 occur naturally in nonpatients as a function of seasonal variation in sunlight. In the present investigation, P300 was studied in a sample of psychiatrically screened normal subjects who were tested at different times of the year. P300 was larger in women than men and varied in relation to season. This pattern is relevant to studies in which subjects are tested under varying sunlight conditions, such as different seasons. In addition, variations in P300 in normal subjects may be relevant to an understanding of the effectiveness of light therapy for patients with seasonal affective disorder.
Event-related brain potentials (ERPs) were recorded from a group of 13 men with severe developmen... more Event-related brain potentials (ERPs) were recorded from a group of 13 men with severe developmental dyslexia and 15 matched normal controls. Auditory and visual stimuli, presented in separate reaction time tasks of graded difficulty, were used to elicit ERPs. No group differences in P300 were seen under relatively undemanding task conditions. However, as task demands increased, visual P300 was reduced in the dyslexic men as compared with the normal readers. An Abbreviated Conners Parent Rating Scale was used to assess retrospectively childhood symptoms of attention-deficit hyperactivity disorder (ADHD). Additional analyses revealed that the dyslexics with a history of many symptoms of ADHD in childhood (high ADHD) accounted for the group differences in P300; the dyslexics with a history of few or no such symptoms (low ADHD) were indistinguishable from the controls at all electrode sites. Furthermore, whereas the low-ADHD dyslexics showed the same hemispheric asymmetry in auditory P300 as did the controls (right > left), auditory P300 was more symmetrically distributed in the high-ADHD dyslexics. The results are interpreted as suggesting that a distinct brain organization may characterize dyslexic men with a history of concomitant deficits in attention.
Perhaps the earliest formal description of the deficit in attention in schizophrenic symptomatolo... more Perhaps the earliest formal description of the deficit in attention in schizophrenic symptomatology was provided by Kraepelin: “It is quite common for them to lose both inclination and ability on their own initiative to keep their attention fixed for any length of time. It is often difficult enough to make them attend at all” (Kraepelin, 1919/1971, p. 6). Matthysse (1978) noted more recently that deficits in attention and information processing are still more consistent than neurochemical findings in schizophrenia. Such results have led many theorists to view impaired attention as the fundamental or core cognitive deficit in the disorder and have led to the suggestion that study of the neurobiological mechanisms of attention may provide’ keys to understanding schizophrenia (Mirsky & Duncan, 1986).
... HC Professor Emeritus Center for Rehabilitation of Brain Injury (CRBI) University of Copenhag... more ... HC Professor Emeritus Center for Rehabilitation of Brain Injury (CRBI) University of Copenhagen Denmark Connie C. Duncan, PhD ... LIST OF CONTRIBUTORS xi George P. Prigatano, PhDNewsome Chair of Clinical Neuropsychology Department of Clinical Neuropsychology ...
Annals of the New York Academy of Sciences, Jan 25, 2006
: The trailblazing research on sleep mechanisms and petit mal epilepsy, conducted during the peri... more : The trailblazing research on sleep mechanisms and petit mal epilepsy, conducted during the period from 1940 through 1970, illuminated the brain substrate for normal consciousness and attention, as well as their disorders. This research helped inform and structure our neuropsychologically based model of the “elements” of attention. The model has been used to assess attention in the research laboratory and clinic, and has led to a “nosology of disorders of attention,” which is presented here in preliminary form. The nosology reviews the possible causes of the symptom(s) of impaired attention, as well as suggesting a blueprint for future research in this area.
The history of attention studies in neuropsychology is in many ways a history of all of neuropsyc... more The history of attention studies in neuropsychology is in many ways a history of all of neuropsychology. Many clinical groups have been studied, and there has been extensive research aimed at relating aspects of attentive behavior to underlying brain structures. In addition, models of the different components of attention have been proposed, dating back nearly 40 years. This review, by nature and necessity selective, begins with early descriptions of symptoms seen in clinical groups and discusses more recent findings, including impaired attention in various disorders, the possible etiology(ies) of impaired attention, and behavioral and psychophysiological studies of attention. Also reviewed are animal models of attention and attention disturbance, the neuroanatomical bases of attention, and speculations on the relation between our concepts of attention and consciousness.
Systematic study of the altered behavioral state seen in absence epilepsy began 50 years ago with... more Systematic study of the altered behavioral state seen in absence epilepsy began 50 years ago with the investigations of reaction time performance, conducted by Schwab (1939). He found, in patients suffering from absence attacks, that prolonged delays in responding to auditory or visual stimuli occurred during the time of their characteristic paroxysmal wave-spike (WS) discharges. In some instances, patients failed to respond during WS paroxysms. In their theoretical exposition of centren-cephalic epilepsy, Penfield and Jasper (1954) accounted for observations such as Schwab’s as reflections of perturbations in the functioning of a widespread system, headquartered in the brain stem, responsible for the maintenance of consciousness. According to this concept, which stemmed in part from the writings of Hughlings Jackson, there exists within the brain a region that forms the “neural substratum of consciousness,” i.e., the highest level of functional integration of sensory and motor processes. Furthermore, seizures in this region are accompanied by unconsciousness (Penfield and Jasper, 1954). This view was certainly compatible with that of Moruzzi and Magoun (1949), who described the functions of the brain-stem reticular formation. The grand Jacksonian concept of Penfield and Jasper has influenced the research and thinking of many neuroscientists, not only about the pathogenesis of the absence disorder but also about the nature of the behavioral disturbance itself.
Journal of Experimental Psychology: Human Perception and Performance, 1975
In two experiments, measures of heart rate and electromyographic activity were obtained from 40 m... more In two experiments, measures of heart rate and electromyographic activity were obtained from 40 male undergraduates while they performed two series of trials involving a sequential information processing task. Each trial consisted of a warning light, three successive tones, and a responded light, separated by 6-sec intervals. In Experiment 1, subjects responded only if the three tones were of different frequencies. Acclerative heart-rate responses to the last tone increased as a function of the significance of that tone. Subsequent cardiac decelerations were only observed if the subject was preparing to make a response. These results were replicated in Experiment 2, in which subjects responded only if two of the preceding tones were of the same frequency. Electromyographic activity was not significantly affected by stimulus significance or response anticipation. The data indicate that cardiac acceleration and deceleration reflect two independent psychological processes, associated with information-processing and decision-making activity on the one hand, and preparatory activity on the other.
OBJECTIVE Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also... more OBJECTIVE Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also be sensitive to chronic effects of mild traumatic brain injury (mTBI) in mid-life. In addition to mTBI history, other clinical factors may also influence ERP measures of brain function. This study's objective was to evaluate the relationship between mTBI history, auditory ERP metrics, and common comorbidities. METHODS ERPs elicited during an auditory target detection task, psychological symptoms, and hearing sensitivity were collected in 152 combat-exposed veterans and service members, as part of a prospective observational cohort study. Participants, with an average age of 43.6 years, were grouped according to positive (n = 110) or negative (n = 42) mTBI history. Positive histories were subcategorized into repetitive mTBI (3 + ) (n = 40) or non-repetitive (1-2) (n = 70). RESULTS Positive history of mTBI was associated with reduced N200 amplitude to targets and novel distractors. In participants with repetitive mTBI compared to non-repetitive and no mTBI, P50 was larger in response to nontargets and N100 was smaller in response to nontargets and targets. Changes in N200 were mediated by depression and anxiety symptoms and hearing loss, with no evidence of a supplementary direct mTBI pathway. CONCLUSIONS Auditory brain function differed between the positive and negative mTBI groups, especially for repetitive injury, which implicated more basic, early auditory processing than did any mTBI exposure. Symptoms of internalizing psychopathology (depression and anxiety) and hearing loss are implicated in mTBI's diminished brain responses to behaviorally relevant and novel stimuli. SIGNIFICANCE A mid-life neurologic vulnerability conferred by mTBI, particularly repetitive mTBI, may be detectable using auditory brain potentials, and so auditory ERPs are a target for study of dementia risk in this population.
... The relationship between phasic decelera-tion and RT, reported by a number of investi-gators ... more ... The relationship between phasic decelera-tion and RT, reported by a number of investi-gators (eg, Connor & Lang, 1969; Coquery & Lacey, 1966; Lacey, 1967; Lacey & Lacey, 1964; Obrist et al., 1969; Obrist, Webb, Sut-terer, & Howard, 1970), failed to receive sup-port from ...
The application of the P300 component of the event-related brain potential to the study of attent... more The application of the P300 component of the event-related brain potential to the study of attentional impairment in schizophrenia is discussed, and two recent studies are described. In one, the relative effects on P300 of stimulus modality and probability were evaluated. The data showed that the P300 is smaller in schizophrenic patients relative to normal controls for low-probability auditory stimuli. Next is described a preliminary report that evaluated whether this P300 reduction reflects a core deficit (trait marker) or clinical symptomatology (state marker). To pursue this question, a group of schizophrenic patients was studied on and off neuroleptic medication. The data showed that improvement in clinical state was highly correlated with increased visual P300 but was uncorrelated with auditory P300. These findings suggest that P300 elicited in the visual modality has the characteristics of a state marker of schizophrenia. In contrast, auditory P300 remains a candidate for a vulnerability trait marker of schizophrenia. The core deficit in schizophrenia thus appears to involve the auditory informationprocessing system, whereas fluctuations in clinical state may be reflected in the visual processing system.
The latency of the P300 component of the event-related brain potential plays a unique role in men... more The latency of the P300 component of the event-related brain potential plays a unique role in mental chronometry. This is illustrated by presenting data from two experiments that addressed the following issues in infonnation processing: a) the locus ofthe effect of stimulus probability on choice reaction time, mid b) the locus of interference in performance on the Stroop color-word test. Using P300 latency to index stimulusevaluation time, it is shown in the first experiment that both stimulus and response processing are affected by stimulus probability. The results suggest that more probable. ev.entsareJdentifiedJ_r-an effect which is reflected in decreases in both P300 and response latency-and that the responses to them are emitted more rapidly-an effect which is reflected in reaction time only. In a second experiment. using the Stroop task, response time was found to vary with the congruence between the stimulus word and the color in which it was printed. However, the duration of stimulus processing, as indexed by P300 latency, remained constant. These results indicate that response competition is the primary source of Stroop interference. It is concluded that P300 latency can be viewed as an important addition to the set of dependent variables available to study human information processing.
Light therapy in patients with seasonal affective disorder has been reported to enhance visual P3... more Light therapy in patients with seasonal affective disorder has been reported to enhance visual P300 amplitude. This findings raises the possibility that variations in P300 occur naturally in nonpatients as a function of seasonal variation in sunlight. In the present investigation, P300 was studied in a sample of psychiatrically screened normal subjects who were tested at different times of the year. P300 was larger in women than men and varied in relation to season. This pattern is relevant to studies in which subjects are tested under varying sunlight conditions, such as different seasons. In addition, variations in P300 in normal subjects may be relevant to an understanding of the effectiveness of light therapy for patients with seasonal affective disorder.
Event-related brain potentials (ERPs) were recorded from a group of 13 men with severe developmen... more Event-related brain potentials (ERPs) were recorded from a group of 13 men with severe developmental dyslexia and 15 matched normal controls. Auditory and visual stimuli, presented in separate reaction time tasks of graded difficulty, were used to elicit ERPs. No group differences in P300 were seen under relatively undemanding task conditions. However, as task demands increased, visual P300 was reduced in the dyslexic men as compared with the normal readers. An Abbreviated Conners Parent Rating Scale was used to assess retrospectively childhood symptoms of attention-deficit hyperactivity disorder (ADHD). Additional analyses revealed that the dyslexics with a history of many symptoms of ADHD in childhood (high ADHD) accounted for the group differences in P300; the dyslexics with a history of few or no such symptoms (low ADHD) were indistinguishable from the controls at all electrode sites. Furthermore, whereas the low-ADHD dyslexics showed the same hemispheric asymmetry in auditory P300 as did the controls (right > left), auditory P300 was more symmetrically distributed in the high-ADHD dyslexics. The results are interpreted as suggesting that a distinct brain organization may characterize dyslexic men with a history of concomitant deficits in attention.
Perhaps the earliest formal description of the deficit in attention in schizophrenic symptomatolo... more Perhaps the earliest formal description of the deficit in attention in schizophrenic symptomatology was provided by Kraepelin: “It is quite common for them to lose both inclination and ability on their own initiative to keep their attention fixed for any length of time. It is often difficult enough to make them attend at all” (Kraepelin, 1919/1971, p. 6). Matthysse (1978) noted more recently that deficits in attention and information processing are still more consistent than neurochemical findings in schizophrenia. Such results have led many theorists to view impaired attention as the fundamental or core cognitive deficit in the disorder and have led to the suggestion that study of the neurobiological mechanisms of attention may provide’ keys to understanding schizophrenia (Mirsky & Duncan, 1986).
... HC Professor Emeritus Center for Rehabilitation of Brain Injury (CRBI) University of Copenhag... more ... HC Professor Emeritus Center for Rehabilitation of Brain Injury (CRBI) University of Copenhagen Denmark Connie C. Duncan, PhD ... LIST OF CONTRIBUTORS xi George P. Prigatano, PhDNewsome Chair of Clinical Neuropsychology Department of Clinical Neuropsychology ...
Annals of the New York Academy of Sciences, Jan 25, 2006
: The trailblazing research on sleep mechanisms and petit mal epilepsy, conducted during the peri... more : The trailblazing research on sleep mechanisms and petit mal epilepsy, conducted during the period from 1940 through 1970, illuminated the brain substrate for normal consciousness and attention, as well as their disorders. This research helped inform and structure our neuropsychologically based model of the “elements” of attention. The model has been used to assess attention in the research laboratory and clinic, and has led to a “nosology of disorders of attention,” which is presented here in preliminary form. The nosology reviews the possible causes of the symptom(s) of impaired attention, as well as suggesting a blueprint for future research in this area.
The history of attention studies in neuropsychology is in many ways a history of all of neuropsyc... more The history of attention studies in neuropsychology is in many ways a history of all of neuropsychology. Many clinical groups have been studied, and there has been extensive research aimed at relating aspects of attentive behavior to underlying brain structures. In addition, models of the different components of attention have been proposed, dating back nearly 40 years. This review, by nature and necessity selective, begins with early descriptions of symptoms seen in clinical groups and discusses more recent findings, including impaired attention in various disorders, the possible etiology(ies) of impaired attention, and behavioral and psychophysiological studies of attention. Also reviewed are animal models of attention and attention disturbance, the neuroanatomical bases of attention, and speculations on the relation between our concepts of attention and consciousness.
Systematic study of the altered behavioral state seen in absence epilepsy began 50 years ago with... more Systematic study of the altered behavioral state seen in absence epilepsy began 50 years ago with the investigations of reaction time performance, conducted by Schwab (1939). He found, in patients suffering from absence attacks, that prolonged delays in responding to auditory or visual stimuli occurred during the time of their characteristic paroxysmal wave-spike (WS) discharges. In some instances, patients failed to respond during WS paroxysms. In their theoretical exposition of centren-cephalic epilepsy, Penfield and Jasper (1954) accounted for observations such as Schwab’s as reflections of perturbations in the functioning of a widespread system, headquartered in the brain stem, responsible for the maintenance of consciousness. According to this concept, which stemmed in part from the writings of Hughlings Jackson, there exists within the brain a region that forms the “neural substratum of consciousness,” i.e., the highest level of functional integration of sensory and motor processes. Furthermore, seizures in this region are accompanied by unconsciousness (Penfield and Jasper, 1954). This view was certainly compatible with that of Moruzzi and Magoun (1949), who described the functions of the brain-stem reticular formation. The grand Jacksonian concept of Penfield and Jasper has influenced the research and thinking of many neuroscientists, not only about the pathogenesis of the absence disorder but also about the nature of the behavioral disturbance itself.
Journal of Experimental Psychology: Human Perception and Performance, 1975
In two experiments, measures of heart rate and electromyographic activity were obtained from 40 m... more In two experiments, measures of heart rate and electromyographic activity were obtained from 40 male undergraduates while they performed two series of trials involving a sequential information processing task. Each trial consisted of a warning light, three successive tones, and a responded light, separated by 6-sec intervals. In Experiment 1, subjects responded only if the three tones were of different frequencies. Acclerative heart-rate responses to the last tone increased as a function of the significance of that tone. Subsequent cardiac decelerations were only observed if the subject was preparing to make a response. These results were replicated in Experiment 2, in which subjects responded only if two of the preceding tones were of the same frequency. Electromyographic activity was not significantly affected by stimulus significance or response anticipation. The data indicate that cardiac acceleration and deceleration reflect two independent psychological processes, associated with information-processing and decision-making activity on the one hand, and preparatory activity on the other.
Uploads
Papers by Connie Duncan