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PubMed1985

Motor and cognitive interference effects on unimanual tapping rates.

Experiments conducted on both normal and disordered populations have led to the hypothesis that the left hemisphere's specialization for language results from its control over motor activities. This control is reflected in the lateralized disruption of manual activity during cerebral time-sharing tasks. Recent studies have challenged this hypothesis, stating that the interference effects reflect both cognitive and motor mechanisms in the left hemisphere. This experiment investigates whether the left hemisphere's control over speech involves both of these components or is purely motor. The question was examined by measuring the effect of concurrent hemispheric activity on single-finger tapping rates. Forty subjects tapped under two conditions: speaking and listening. The data show there may be both motor and cognitive mechanisms involved in left-hemisphere control.

Adult↗

PubMed2006

Cognitive function and symptoms in adolescents with schizotypal personality disorder.

Cognitive deficits have been documented in schizophrenia and spectrum disorders. This study examines cognitive functioning and its relation to symptoms in adolescents with schizotypal personality disorder (SPD). Participants are 89 adolescents recruited for a study of youth at risk for Axis I disorders, especially psychosis. At intake, 34 met criteria for SPD, 38 for another Axis II disorder and/or conduct disorder (Other disorder-OD), and 17 did not currently meet criteria for any DSM-IV disorder (normal control-NC). At initial assessment, cognitive functioning was measured using subtests from the Wechsler Intelligence Scales and Wechsler Memory Scales (WMS), and symptoms were measured using the Structured Interview for Prodromal Symptoms (SIPS). At the time of this report, 50 were readministered the SIPS at 1-year follow-up (T2). The SPD group scored significantly below the NC group on the Arithmetic subtest of the Wechsler Intelligence Scales, but there was only limited evidence of group differences on the WMS. Poorer performance on the Wechsler Intelligence Scales was associated with greater severity of negative and disorganized symptoms. Deficits on the WMS were linked with more severe disorganized symptoms. The findings reported here are consistent with previous reports of limited cognitive deficits in adolescents with SPD, with the most marked deficits in mental arithmetic. The associations between symptoms and cognitive scores parallel those observed in adults with schizophrenia and spectrum disorder, and they are consistent with the notion that negative symptoms are more stable and partially reflect premorbid cognitive functions.

Adolescent↗

PubMed2004

Cognitive change in patients undergoing hypnotherapy for irritable bowel syndrome.

OBJECTIVE: Impaired quality of life and psychological distress are common in irritable bowel syndrome (IBS) and may be associated with unhelpful cognitions. Hypnotherapy (HT) is effective in improving both symptoms and quality of life in patients with IBS, and this study was designed to determine whether this improvement is reflected in cognitive change using a validated scale recently developed for use in such patients. METHOD: A total of 78 IBS patients completed a validated symptom-scoring questionnaire, the Hospital Anxiety and Depression (HAD) Scale and the Cognitive Scale for Functional Bowel Disorders (FBDs), before and after 12 sessions of gut-focused HT. RESULTS: HT resulted in improvement of symptoms, quality of life and scores for anxiety and depression (all P's<.001). IBS-related cognitions also improved, with reduction in the total cognitive score (TCS; P<.001) and all component themes related to bowel function (all P<.001). Cognitions were related to symptom severity because the most abnormal cognitive scores were observed in patients with the highest symptom scores (P<.001). Furthermore, a reduction in symptom score following treatment correlated with an improvement in the cognitive score (P<.001). Regression analysis confirmed that the cognitive score had independence from the other scores and did not serve solely as a proxy for symptom improvement. CONCLUSION: This study shows that symptom improvement in IBS with HT is associated with cognitive change. It also represents an initial step in unravelling the many possible mechanisms by which treatments such as HT might bring about improvement.

Adolescent↗

PubMed2002

Serum concentration of S-100 protein in assessment of cognitive dysfunction after general anesthesia in different types of surgery.

BACKGROUND: S-100 protein serum concentration (S-100) serves as a marker of cerebral ischemia in cardiac surgery, head injury and stroke. In these circumstances S-100 corresponds well with the results of neuropsychological tests. The aim of the present study was to investigate the value of S-100 and neuron specific enolase (NSE) in reflecting postoperative cognitive deficit (POCD) after general surgical procedures. METHODS: One hundred and twenty patients undergoing vascular, trauma, urological or abdominal surgery were investigated. Serum values of S-100 and NSE were determined preoperatively and 0.5, 4, 18 and 36 h postoperatively. Neuropsychological tests for detecting POCD were performed preoperatively and on day 1, 3, and 6 after the operation. A decline of more than 10% in neuropsychological test results was regarded as POCD. Furthermore, we retrospectively compared the S-100 in patients with and without POCD in different types of surgery. RESULTS: According to our definition, forty-eight patients had POCD (95% confidence interval: 37.5-58.5). These patients showed higher serum concentrations of S-100 (median 024 ng/ml; range 0.01-3.3 ng/ml) compared with those without POCD (n=69; median 0.14 ng/ml; range 0-1.34 ng/ml) 30 min postoperatively (P=0.01). Neuron specific enolase was unchanged during the course of the study. Differences of S-100 in patients with and without POCD were found in abdominal and vascular surgery but not in urological surgery. CONCLUSION: When all patients are pooled, S-100 appears to be suitable in the assessment of incidence, course and outcome of cognitive deficits. We suspect that in some surgical procedures, such as urological surgery, S-100 appears to be of limited value in detecting POCD. Neuron specific enolase did not reflect neuropsychological dysfunction after noncardiac surgery.

Adolescent↗

PubMed2005

Transient gamma-band response is dissociated from sensory memory as reflected by MMN.

The auditory gamma-band transient oscillatory response has been considered to reflect early cognitive processing and attention triggering, as has been suggested of the mismatch negativity (MMN). We examined whether the auditory gamma-band response was related to sensory memory as reflected by MMN. During the electroencephalogram (EEG) recordings, approximately 2000 click sounds were presented to nine healthy adult subjects with constant SOA of 120 or 170 ms in an ignored condition. At a probability of 10%, a click sound was randomly omitted from the stimulus sequence. EEG epochs responding to omitted clicks and to click sounds were averaged for analysis, respectively, and then those were convoluted by Gabor wavelet for the gamma-band response calculation. The MMN to a deviant omission in a sequence of click sounds was elicited with SOA of 120 ms which was shorter than the duration of temporal window of integration, whereas no MMN was elicited with SOA of 170 ms. In contrast with the MMN, the transient gamma-band response clearly commenced after the stimuli but not after the omissions, regardless whether SOA was short or long. The findings indicate that the brain process underlying the transient gamma-band response should be dissociated from the sensory memory function.

Adult↗

PubMed1996

Revealing the distinction between perception and cognition through intra-individual variability of visual evoked responses.

Searching for a method to objectively detect the cognitive activity of the brain, the variability of visual evoked responses (ER) was analysed in 75 human subjects and 10 animals. The individual ERs of a normal subject were found typically very scattered in the first approx. 120 ms after stimulation, converging at 160-220 ms and then diverging again progressively. This variability pattern (VP) is event-related and is not attributable to background noise. On the other hand, statistically significant correlation showed that in most patients, with anatomically intact visual structures but with pronounced mental troubles, the VP is absent and the ERs are randomly scattered. Based on these results we consider that the event-related variability reflects the cognition function of the subjects and that it is instrumental in evidencing the distinction between cognitive and perceptive processes. The results are further consistent with the idea that cognition implies the chaotic activity of certain neural populations and that the VP reflects this chaotic, non-repetitive, non-linear and impredictable but effective neural activity.

Aged↗

PubMed2000

Measuring cognitive processes underlying picture naming in Alzheimer's and cerebrovascular dementia: a general processing tree approach.

Existing data from the Boston Naming Test were analyzed using standard statistical methods and with a General Processing Tree (GPT) model in an attempt to differentiate between patients with Alzheimer's Disease (AD) and Cerebrovascular dementia (CVD), matched for severity, and age-matched healthy controls. The GPT approach enables the estimation of parameters reflecting underlying cognitive processes (e.g., perceptual analysis, lexical access) based on categorical data. Compared to traditional analyses of proportion correct and of errors, the analysis with the GPT model was more sensitive in detecting differences between patient groups, as well as the source of these differences. Among the differences were two, evident in a comparison between very mild AD and very mild CVD patients: standard analyses did not reveal a significant difference between these groups; but the GPT analysis revealed that the CVD patients had significantly higher estimates than the AD patients on parameters reflecting lexical access and phonological realization.

Aged↗

PubMed1997

Association of premorbid intellectual function with cerebral metabolism in Alzheimer's disease: implications for the cognitive reserve hypothesis.

OBJECTIVE: Clinical heterogeneity in Alzheimer's disease has been widely observed. One factor that may influence the expression of dementia in Alzheimer's disease is premorbid intellectual ability. It has been hypothesized that premorbid ability, as measured by educational experience, reflects a cognitive reserve that can affect the clinical expression of Alzheimer's disease. The authors investigated the relation between estimates of premorbid intellectual function and cerebral glucose metabolism in patients with Alzheimer's disease to test the effect of differing levels of premorbid ability on neurophysiological dysfunction. METHOD: In a resting state with eyes closed and ears occluded, 46 patients with Alzheimer's disease were evaluated with positron emission tomography and [18F]-2-fluoro-2-deoxy-D-glucose to determine cerebral metabolism. Premorbid intellectual ability was assessed by a demographics-based IQ estimate and performance on a measure of word-reading ability. RESULTS: After the authors controlled for demographic characteristics and dementia severity, both estimates of premorbid intellectual ability were inversely correlated with cerebral metabolism in the prefrontal, pre-motor, and left superior parietal association regions. In addition, the performance-based estimate (i.e., reading ability) was inversely correlated with metabolism in the anterior cingulate, paracentral, right orbitofrontal, and left thalamic regions, after demographic and clinical variables were controlled for. CONCLUSIONS: The results suggest that higher levels of premorbid ability are associated with greater pathophysiological effects of Alzheimer's disease among patients of similar dementia severity levels. These findings provide support for a cognitive reserve that can alter the clinical expression of dementia and influence the neurophysiological heterogeneity observed in Alzheimer's disease.

Aged↗

PubMed1997

Memory activation and expectancy as prospective predictors of alcohol and marijuana use.

This study examined whether indicators of drug-related memory associations predicted drug use prospectively. The predictive effects of outcome expectancies, sensation seeking, and other variables also were investigated. The results revealed that the memory association measures significantly predicted subsequent drug use. Outcome expectancies and sensation seeking predicted alcohol use, but not marijuana use. The findings suggest 2 possibly different aspects of cognition involved in drug use motivation: (a) a memory activation or implicit cognition component, representing the effects of memory associations that are prompted relatively spontaneously by the prevailing motivational and situational circumstances and (b) an outcome expectancy component, which is more likely to reflect explicit cognitions involved in introspection and deliberate decision-making processes.

Adult↗

PubMed1993

Introduction to special section: theoretical developments in the cognitive psychotherapies.

The cognitive psychotherapies have developed and substantially differentiated since their inception in the 1950s. Six major themes in their theoretical development are discussed: (a) the differentiation of rationalist and constructivist therapies and metatheories of knowing; (b) the acknowledgement of social, biological, and embodiment processes in therapy; (c) the recognition of unconscious processes; (d) an increasing focus on self-organizing and self-protective processes in life span personality development, with such processes being embedded in interpersonal and social system dynamics; (e) a shift toward different views of emotionality and the incorporation of experiential techniques; and (f) a synergistic involvement in the psychotherapy integration movement. The cognitive psychotherapies reflect remarkable activity, a point illustrated and elaborated in the articles that constitute this special section.

Adaptation, Psychological↗

PubMed1986

An examination of the relation of individual difference variables to loneliness.

This study investigated the relation of five individual difference variables (extroversion, depression, self-esteem, neuroticism, and attitude toward others) to loneliness. The relative contributions of two different models that might explain these relations were examined. One model suggests that individual difference variables are related to loneliness through the mediation of social network variables; that is, individual difference variables may reduce people's motivation and/or ability to build and maintain social relationships, which in turn leads to loneliness. The second model, the cognitive bias model, states that both the individual difference variables and loneliness are influenced by the same intrapersonal, cognitive processes. Some people are prone to negative affect and tend to evaluate themselves and their relationships negatively. The relations of self-esteem, neuroticism, and depression to loneliness were hypothesized to reflect the cognitive bias model, while extroversion and attitudes toward others were hypothesized to be related to loneliness through the mediation of social network variables. Eighty-two female and 42 male adults completed measures of loneliness and the five individual difference variables, as well as an instrument assessing their social networks. The results indicated partial support for both models for each of the individual difference variables. Together, the two models did a good job of explaining the correlations of the individual difference variables and loneliness. The implications of these findings, as well as their relation to previous research, are discussed.

Adult↗

PubMed1985

Some cognitive correlates of schizophrenic illnesses.

A battery of tests was developed to assess verbal, non-verbal and mixed cognitive functions. Interest was based on pattern of response rather than absolute scores. The subjects were 167 men held in prison on criminal charges or in a maximum security hospital after conviction. The present paper deals exclusively with two subgroups: the 61 schizophrenic men and the 41 men with no psychiatric disorder. The schizophrenic group as a whole presented a very different cognitive pattern from the 'normal' men. First, with the exception of the vocabulary subtest of the WAIS, the schizophrenics were inferior on all tests, whether verbal, non-verbal or mixed function. Secondly, they showed considerably more variation within subtests. The schizophrenic sample was therefore subdivided into four clinical groups. Each showed a distinctive cognitive profile. It is argued that these cognitive differences reflect real differences in the disorder and type of illness being experienced by members of these subgroups.

Cognition Disorders↗

PubMed1976

Reflection-impulsivity and need for achievement in emotionally disturbed children.

Reflection-impulsivity is the cognitive dimension proposed by Kagan and his colleagues to describe the differences in children's resolution to response uncertainty. Impulsive children tend to respond quickly without considering all of the available alternatives and consequently make many mistakes. Reflecttive children consider all of the available alternatives, withhold responding until they have a high probability of being correct, and consequently make few mistakes. The primary dynamic underlying a reflective cognitive style is hypothesized to be a fear of making a mistake: the greater the fear, the more reflective the child is and the more cautiously he performs. On the other hand, minimal anxiety over a potentially inaccurate answer is likely to result in an impulsive performance.

Achievement↗

PubMed2006

Psychophysiological differences in identical twins discordant for schizophrenia: a critical index for the onset of schizophrenia.

It has been hypothesized that not only genetic but also environmental factors contribute to the onset of schizophrenia. We therefore conducted psychophysiological studies on a pair of identical twins discordant for schizophrenia, to differentiate non-genetic from genetic indexes possibly associated with this disease. The affected and unaffected twins were 28 year-old females. The affected twin was diagnosed as having schizophrenia based on the Diagnosis and Statistical Manual of Mental Disorders, third edition revised (DMS-III-R), whereas the unaffected twin had no psychiatric disorders. The brain potentials evoked by visual stimulation (visual event-related potential [visual ERP]) were recorded. The components of the visual ERP, which are believed to reflect pattern cognition, semantic processing and the failure to use preceding word information, were compared with normal subjects. Both twins showed abnormal semantic processing and similar failure to use preceding word information. Abnormality of semantic processing was marked in the affected twin. These results indicate that failure to use preceding word information might reflect only genetic factors, whereas abnormal semantic processing might reflect both genetic and non-genetic factors because the affected twin was considered to show accelerated deterioration after the disease onset. However, only the affected twin showed abnormal pattern cognition, which might be attributable to non-genetic factors such as an acquired vulnerability to schizophrenia. We suggest that the impairment of pattern cognition evaluated by visual ERP may be a critical index for the onset of schizophrenia.

Adult↗

PubMed1999

The nonlinear, complex sequential organization of behavior in schizophrenic patients: neurocognitive strategies and clinical correlations.

BACKGROUND: Thought disorder is a hallmark of schizophrenia and can be inferred from disorganized behavior. Measures of the sequential organization of behavior are important because they reflect the cognitive processes of the selection and sequencing of behavioral elements, which generate observable and analyzable behavioral patterns. In this context, sequences of choices generated by schizophrenic patients in a two-choice guessing task fluctuate significantly, which reflects an "oscillating dysregulation" between highly predictable and highly unpredictable subsequences within a single test session. In this study, we aimed to clarify the significance of dysregulation by seeing whether demographic, clinical, neuropsychological, and psychological measures predict the degree of dysregulation observed on this two-choice task. METHODS: Thirty schizophrenic patients repeatedly performed a LEFT or RIGHT key press that was followed by a stimulus, which occurred randomly on the left or right side of the computer screen. Thus, the stimulus location had nothing to do with the key press behavior. The range of key press sequence predictabilities as measured by the dynamical entropy was used to quantify the dysregulation of response sequences and reflects the range of fixity and randomness of the responses. A factor analysis was performed and step-wise multiple regression analyses were used to relate the factor scores to demographic, clinical, symptomatic, Wisconsin Card Sorting Test (WCST), and Rorschach variables. RESULTS: The LEFT/RIGHT key press sequences were determined by three factors: 1) the degree of win-stay/lose-shift strategy; 2) the degree of contextual influence on the current choice; and 3) the degree of dysregulation on the choice task. Demographic and clinical variables did not predict any of the three response patterns on the choice task. In contrast, the WCST and Rorschach test predicted performance on various factors of choice task response patterns. CONCLUSIONS: Schizophrenic patients employ several rules, i.e., "win-stay/lose-shift" and "decide according to the previous choice," that fluctuate significantly when generating sequences on this task, confirming that a basic behavioral dysregulation occurs in a single schizophrenic subject across a single test session. The organization or the "temporal architecture" of the behavioral sequences is not related to symptoms per se, but is related to deficits in executive functioning, problem solving, and perceptual organizational abilities.

Adult↗

PubMed2001

Emotion-induced changes in human medial prefrontal cortex: II. During anticipatory anxiety.

Regional cerebral blood flow (BF) was examined in the human medial prefrontal cortex (MPFC) with positron emission tomography during anticipatory anxiety. Transient anxiety was induced in normal subjects by having them anticipate a painful shock to the fingers of one hand. BF was decreased during anticipatory anxiety, relative to an eyes-closed resting condition, in two regions of the MPFC (Brodmann Areas 10/32 and 24/25). BF decreases in these areas were inversely correlated with anxiety self rating, such that the least anxious subjects exhibited the largest BF reductions, whereas the most anxious subjects showed no significant BF reduction or a slight increase. BF changes in MPFC and in the midbrain were correlated with each other and with anxiety self rating. These results are consistent with the hypothesis that BF reductions in MPFC, previously observed in cognitive tasks, reflect a dynamic balance between focused attention and subject anxiety and may occur from a functionally active baseline or default state. The characterization of such relationships within the human brain enables new insights into the integration of cognition and emotion.

Adult↗

PubMed2002

Reducing diagnostic errors in medicine: what's the goal?

This review considers the feasibility of reducing or eliminating the three major categories of diagnostic errors in medicine: "No-fault errors" occur when the disease is silent, presents atypically, or mimics something more common. These errors will inevitably decline as medical science advances, new syndromes are identified, and diseases can be detected more accurately or at earlier stages. These errors can never be eradicated, unfortunately, because new diseases emerge, tests are never perfect, patients are sometimes noncompliant, and physicians will inevitably, at times, choose the most likely diagnosis over the correct one, illustrating the concept of necessary fallibility and the probabilistic nature of choosing a diagnosis. "System errors" play a role when diagnosis is delayed or missed because of latent imperfections in the health care system. These errors can be reduced by system improvements, but can never be eliminated because these improvements lag behind and degrade over time, and each new fix creates the opportunity for novel errors. Tradeoffs also guarantee system errors will persist, when resources are just shifted. "Cognitive errors" reflect misdiagnosis from faulty data collection or interpretation, flawed reasoning, or incomplete knowledge. The limitations of human processing and the inherent biases in using heuristics guarantee that these errors will persist. Opportunities exist, however, for improving the cognitive aspect of diagnosis by adopting system-level changes (e.g., second opinions, decision-support systems, enhanced access to specialists) and by training designed to improve cognition or cognitive awareness. Diagnostic error can be substantially reduced, but never eradicated.

Cognition↗

PubMed2005

Performance on neurocognitive tests by co-twins to dementia cases compared to normal control twins.

Nondemented co-twins of twins who were diagnosed as demented were compared to randomly selected members of normal control twin pairs in which both members of the pair were nondemented. Nondemented co-twins included 23 monozygotic and 62 dizygotic twins; there were 27 normal control twins. Both monozygotic and dizygotic nondemented co-twins of dementia cases scored significantly lower than normal control twins on 5 of 10 cognitive tests. Moreover, monozygotic co-twins of dementia cases had a generally lower score profile than dizygotic co-twins of dementia cases did. These findings show that being at greater genetic risk for dementia is reflected in cognitive performance even in the absence of a diagnosis of dementia.

Aged↗