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Results for “Cognitive Reflection”

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At least 361 records · Page 20Linked to original sources

PubMed2004

Mechanism of disorientation in Alzheimer's disease.

In nondemented amnesics, disorientation mostly reflects a failure to select memories that pertain to ongoing reality (increased temporal context confusion; TCC), a failure strongly associated with orbitofrontal damage. In the present study, we used the same paradigm--2 runs of a continuous recognition task--in 23 patients with mild to moderate Alzheimer's disease (AD) (Clinical Dementia Rating Scale score of 1-2). We found that disorientation was frequent in this sample (52%). However, although it correlated moderately well with general measures of dementia severity, verbal episodic memory and executive functioning, there was no significant correlation with TCC. Thus, disorientation in AD appears to reflect general cognitive decline rather than a specific cognitive failure such as increased TCC. This finding is compatible with the different distribution of degeneration in AD and the orbitofrontal damage typically present in severely disoriented amnesics.

Aged↗

PubMed1996

Cerebral blood flow changes in limbic regions induced by unsolvable anagram tasks.

OBJECTIVE: The study addressed the question of whether unsolvable as opposed to solvable cognitive problems activate discrete neuronal systems in the human brain. METHOD: Twelve healthy humans tried to solve unsolvable anagrams. Solvable anagrams and a resting baseline after each anagram task served as control conditions in a within-subject design. Activation was measured with the equilibrium infusion method by using 15O-labeled water and positron emission tomography, with absolute quantitation of anatomically defined regional cerebral blood flow (CBF). RESULTS: Compared to rest, both anagram tasks increased activity in frontal and temporal regions. The soluble task condition increased hippocampal activation and decreased mammillary bodies activity, while unsolvable anagrams were associated with increased CBF to the mamillary bodies and amygdala and decreased hippocampal activity. CONCLUSIONS: A limbic network integrating negative emotion and cognition seems reflected in reciprocal diencephalic and limbic activation with solvable and unsolvable anagrams. Since unsolvable anagrams have been used to induce learned helplessness in humans, this finding may provide an initial step toward clarifying its neural substrate.

Adult↗

PubMed2004

Dysregulation of arousal and amygdala-prefrontal systems in paranoid schizophrenia.

OBJECTIVE: The authors investigated impaired differentiation of limbic-prefrontal systems by autonomic arousal in schizophrenia. It was predicted that paranoid patients would be distinguished by a disjunction of hyperarousal but reduced amygdala and medial prefrontal activity relative to both healthy comparison subjects and patients with nonparanoid schizophrenia. METHOD: Pictures depicting facial expressions of fear were presented to 27 schizophrenia patients (13 paranoid, 14 nonparanoid) and 22 matched healthy comparison subjects in an implicit perception task to evoke limbic activity. Simultaneous functional magnetic resonance imaging and skin conductance arousal recordings were acquired during presentation of faces expressing fear or neutral emotion. Responses to fear stimuli were further examined by contrasting those that were associated with a skin conductance response ("with arousal") and those that were not ("without arousal"). RESULTS: In the comparison subjects, arousal dissociated amygdala/medial prefrontal ("visceral") networks and hippocampus/lateral prefrontal ("context") networks for fear perception. Excessive arousal responses were elicited in the schizophrenia subjects, but there was an associated reduction in amygdala/medial prefrontal activity. This disjunction was pronounced in paranoid patients relative to both healthy subjects and nonparanoid patients. Paranoid patients also showed a relatively greater prefrontal deficit for "without-arousal" responses. CONCLUSIONS: This is the first study to reveal a functional disconnection in autonomic and central systems for processing threat-related signals in patients with paranoid schizophrenia. Paranoid cognition may reflect an internally generated cycle of misattribution regarding incoming fear signals due to a breakdown in the regulation of these systems.

Adult↗

PubMed1995

Rate of information processing in patients with Wilson's disease.

This study investigated the rate of information processing, independent of motor speed, in neurologically affected Wilson's disease (WD) patients. Two scanning tasks based on the Sternberg item-recognition paradigm were administered to 17 neurologically symptomatic WD patients and 17 normal control (NC) subjects. Although WD subjects do have longer response latencies than NC subjects, their rate of information processing is the same as the rate of the NC subjects. The longer response latencies are attributable to their motor deficits. The clear impact of motor impairment on test performance underlines the necessity for specialized assessment measures that can accurately reflect the cognitive abilities of motor-impaired patients. These findings suggest that Wilson's disease is not characterized by slowed information processing.

Adolescent↗

PubMed2005

A web-based tutorial to enhance student learning of activity analysis.

BACKGROUND: This paper describes the impact on learning of a web-based tutorial for the application of activity analysis, with occupational therapy students, at McGill University, Montreal, Quebec. This tutorial offers unique, interactive instructional strategies allowing for self-directed higher cognitive and reflective learning, which has not been possible, to date, in current web-based technology. SCOPE: Through repeated practice, students collaboratively (in dyads) apply concepts of activity analysis, and receive immediate feedback by comparing their answers to a standard. METHODS AND RESULTS: Comparisons of performance outcomes on summative exams before and after implementation of the tutorial are made, suggesting a decrease in variance scores indicating fewer students are falling below the class average. These results are attributed to opportunities to practice activity analysis and to receive immediate feedback. PRACTICE IMPLICATIONS: Web-based instruction can impact student learning if the instructional strategies ensure coherence with all other instructional components, match the learning outcomes, facilitate self-directed and collaborative learning, and allow for practice and feedback.

Canada↗

PubMed2003

Two levels of intervention in low-income women with depressive symptoms: compliance and programme assessment.

AIMS: This study reports on the evaluation of a brief group intervention for women of limited means with depressive symptoms. METHOD: A comparison design was used with pre-, post- and four-month follow-up assessments for 93 women in the group intervention condition who were given six two-hour sessions of psycho-educational intervention, and 42 women in a minimum individual condition who received a 20-minute explanation in addition to the educational material, which yielded the following results. RESULTS: Both conditions were effective in motivating participants to engage in self-help activities (making time for themselves every week, using writing as a means of sorting out problems, talking to someone about their problems and carrying out the reflection and cognitive behavioural exercises) and to seek further professional help when necessary. The intervention condition was more positively evaluated since participants regarded it as having a greater influence on their life and problems. Influence was related to better understanding and coping with problems, mood improvement, changes in the way they thought about things, knowing themselves better and being more accepting of themselves. CONCLUSIONS: The results suggest that both interventions tackle important issues related to depression in women but further data are needed for a better understanding of this relationship.

Adult↗

PubMed2003

Pharmacokinetic and pharmacodynamic interactions of oral midazolam with ketoconazole, fluoxetine, fluvoxamine, and nefazodone.

The objective of this study was to investigate pharmacokinetic and pharmacodynamic interactions between midazolam and fluoxetine, fluvoxamine, nefazodone, and ketoconazole. Forty healthy subjects were randomized to receive one of the four study drugs for 12 days in a parallel study design: fluoxetine 60 mg per day for 5 days, followed by 20 mg per day for 7 days; fluvoxamine titrated to a daily dose of 200 mg; nefazodone titrated to a daily dose of 400 mg; or ketoconazole 200 mg per day. All 40 subjects received oral midazolam solution before and after the 12-day study drug regimen. Blood samples for determination of midazolam concentrations were drawn for 24 hours after each midazolam dose and used for the calculation of pharmacokinetic parameters. The effects of the study drugs on midazolam pharmacodynamics were assessed using the symbol digit modalities test (SDMT). The mean area under the curve (AUC) for midazolam was increased 771.9% by ketoconazole and 444.0% by nefazodone administration. However, there was no significant change in midazolam AUC as a result of fluoxetine (13.4% decrease) and a statistical trend for fluvoxamine (66.1% increase) administration. Pharmacodynamic data are consistent with pharmacokinetic data indicating that nefazodone and ketoconazole resulted in significant increases in midazolam-related cognition impairment. The significant impairment in subjects' cognitive function reflects the changes in midazolam clearance after treatment with ketoconazole and nefazodone. These results suggest that caution with the use of midazolam is warranted with potent CYP3A4 inhibitors.

Administration, Oral↗

PubMed2001

Social cognitive factors predicting the health of elders.

The social cognitive model of health is primarily concerned with influences on a person's decisions to perform health behaviors. In this study, the relationships among social cognitive factors reflecting enabling skills (learned resourcefulness), internal motivation for health (health self-determinism), and help responses (coping responses) and a measure of physical and psychosocial health were examined in 137 chronically ill elders. Gender, race, and number of chronic conditions were predictors of learned resourcefulness. Learned resourcefulness was associated with the use of informal help, whereas health self-determinism was related to self-help and formal help. None of the help responses were significant predictors of health. Model testing revealed that greater resourcefulness or skill in coping with stressful situations was the most important predictor of health. Strategies are recommended to help elders achieve optimal health.

Adaptation, Psychological↗

PubMedDate not supplied

Depressive symptoms in Parkinson's disease: a comparison with disabled control subjects.

A high incidence of depressive symptoms has been observed in patients with Parkinson's disease (PD). PD involves a loss of central monoamines, and a decrease of monoamines has been implicated in depression; therefore, it is possible that depressive symptoms in PD result from the loss of endogenous neurotransmitters. However, it is equally possible that depressive symptoms represent a reaction to the chronic disabling course of PD. By comparing depressive symptoms in PD patients to those in matched patients with other chronic disabling diseases not involving a loss of central monoamines, it may be possible to decide between these alternatives. Thus, depressive symptoms were assessed in 45 patients with PD and 24 disabled controls that did not differ from the PD subjects on a measure of functional disability. Results showed that PD subjects obtained significantly higher total scores on the Beck Depression Inventory (BDI) than controls. PD subjects scored significantly higher than controls on BDI items grouped to reflect cognitive-affective and somatic depressive symptoms. The BDI scores of PD subjects were not reliably related to age, sex, duration of PD, or clinical ratings of PD symptom severity or functional disability. Self-rated disability and the number of recent medical problems were the greatest predictors of depressive symptoms. These findings supported the hypothesis that depressive symptoms in PD may not represent solely a reaction to disability.

Activities of Daily Living↗

PubMed2004

Making sense of traumatic experiences: telling your life with fragile X syndrome.

The discourse of individuals with fragile X syndrome has been described as fragmented, tangential, and associatively connected, resulting in autobiographical narratives that are incoherent and difficult to understand. In this article, the authors discuss the case of an adolescent female with moderate mental retardation due to fragile X syndrome. The analysis of her autobiographical stories, rather than being primarily reflective of cognitive impoverishment, reveals a different--narrative--mode of thought. The authors present and examine some of her narratives in terms of their specific functions: communication, coherence, exploration, distancing, and evaluation. Their findings suggest that narrative analysis can be an important complement to traditional neuropsychological assessment.

Adolescent↗

PubMed2001

Qualitative analysis of verbal fluency output: review and comparison of several scoring methods.

We compared three approaches to scoring qualitative aspects of verbal fluency performance in 88 healthy young adults. Phonemic and semantic fluency output was scored for word clustering and switching between clusters. Convergent validity analyses using other tests presumed to tap into strategy use (California Verbal Learning Test, Ruff Figural Fluency Test) support scoring of phonemic and semantic clusters on both fluency tasks. Task-discrepant clustering (e.g., semantic clustering on phonemic fluency) may index intentional strategy use on both fluency tasks, whereas task consistent clustering (e.g., phonemic clustering on phonemic fluency) appears strategic only on semantic fluency. Switching can be decomposed into subtypes that appear to reflect different cognitive processes on phonemic versus semantic fluency. Principal components analyses suggest that earlier scoring methods do not fully capture the "process" aspects of verbal fluency performance.

Adult↗

PubMed2004

Correlation between P300 and EEG rhythm in schizophrenia.

We hypothesized that cognitive deficits reflected by P300 abnormality and distorted EEG rhythm in schizophrenia, which might share the subcortical generation system, could be closely associated with each other. Our goal is to assess the relationship between P300 and EEG rhythm generation in schizophrenics. Quantitative EEG (QEEG) in resting condition and P300 during auditory oddball paradigm were recorded with 25 unmedicated patients. Additionally, lateral ventricular-brain ratio (LV-BR), which partially reflects thalamic volume, was measured using CT scan. Brief Psychotic Rating Scale (BPRS) and Scale for Assessment of Negative Symptoms (SANS) were also rated. P300 amplitudes at Pz positively correlated with theta and slow alpha power before pharmacotherapy, however, the correlation tended to be confined to fast alpha after pharmacotherapy. BPRS and SANS showed no significant correlation with QEEG. High frequency bands such as fast alpha and beta showed trends to correlate negatively to LV-BR. The lack of correlation between P300 amplitudes and fast alpha power before pharmacotherapy, which was restored after pharmacotherapy, might indicate thalamocortical dysfunction in schizophrenia.

Adolescent↗

PubMed2005

Assessing executive dysfunction in girls with fragile X or Turner syndrome using the Contingency Naming Test (CNT).

The aim of this study was to examine executive function (EF) skills in girls with fragile X or Turner syndrome, using the Contingency Naming Test (CNT). The CNT is a Stroop-like task involving a 1- or 2-attribute contingency rule. We predicted that girls with fragile X would make errors reflecting poor cognitive flexibility and working memory limitations. We predicted that girls with Turner syndrome would have sufficient cognitive flexibility to perform the CNT accurately, but would have difficulty with verbal inhibition and would thus make more self-corrections than girls in a comparison group. The hypotheses were partially supported: relative to their Full Scale IQ-matched comparison group, girls with fragile X or Turner syndrome were slower on the warm-up naming task; girls with fragile X made more errors on the 1-attribute task, and girls with Turner syndrome were less efficient on both the 1- and 2-attribute tasks, without making more self-corrections. These results support previous findings of executive dysfunction associated with fragile X or Turner syndrome. The results suggest that both low IQ and fragile X status contribute to working memory limitations in girls with fragile X and that EF inefficiency in girls with Turner syndrome is due to both working memory limitations and slower response times.

Child↗

PubMed1997

Parental representations, self-view, and interpersonal functioning of older adolescents.

This study examines the relationship between parental object representations, self-representations, and interpersonal relations in a nonclinical sample of older adolescents. It was hypothesized that individuals with parental representations that are conceptually low, hostile, and rejecting would be significantly related to a negative view of self and poor interpersonal relations. The results suggest that parental benevolence, ambitiousness, and conceptual level are significantly related to interpersonal functioning. Parental representations that are qualitatively poor were found to be associated with a negative view of self. However, a high conceptual level of mother was noted to be significantly related to a negative self-representation. The findings generally confirm the nature of the relationship between object representations and self, but also suggest that the structural component of parental representations may reflect a cognitive component of the self rather than an affective one. The difficulties of controlling for depression and method variance issues are also discussed.

Adolescent↗

PubMed2000

Frames of reference for the display of battlefield information: judgment-display dependencies.

In 2 experiments, U.S. Army soldiers viewed computer-generated displays that presented battlefield information from 3 different frames of reference: a 2D plan view display (with contour lines), a 3D exocentric perspective display, and an interactive 3D immersed display. In Experiment 1, soldiers made geographical judgments. The results suggested that both 3D displays suffered from ambiguity of distance estimates but that the 3D immersed display was most accurate for judging whether a location is directly visible from another. In Experiment 2, the 3D exocentric display was compared with a 3D immersed view, coupled with a small 2D inset map, in a more continuous battlefield scenario in which judgments of enemy activity were made. The findings of 3D ambiguity were replicated from Experiment 1. The accuracy of judgments of enemy activity suffered with the immersed display when information necessary to answer correctly did not appear in the initial forward view and required panning to acquire, reflecting the cognitive demands of integration across different views. This display also hindered soldiers' ability to report changes in enemy activity from one scene to the next. The results of this research will help to provide guidelines for the appropriate choice of computer display technology to assist in designing battlefield visualization aids. Caution should be exercised in choosing immersive viewpoints.

Computer Systems↗

PubMed2006

Toward a model of self pathology underlying personality disorders: narratives, metacognition, interpersonal cycles and decision-making processes.

If we want to explain the links between the various and heterogeneous elements--symptoms, dysfunctional forms of behavior and poor social functioning--making up personality disorders, we need model a self pathology that portrays dysfunctions, the links among them, and how their interactions maintain disorders over time. In our view, the most likely elements of self pathology are: a. problematic contents (thoughts and emotions)--experienced subjectively as states of mind and organized in the form of narratives; b. shortfalls in the ability, termed meta-cognition, to reflect on mental states, both of oneself and of others; c. pathogenic interpersonal schemas; and d. maladaptive decision-making processes. These elements get altered in the various personality disorders and interact to form typical pathological organizations. This article seeks to describe a model of self pathology in personality disorders and discuss its current scientific status based on a literature review that spans several disciplines. The model is illustrated with an example of how the pathogenic elements can interact to form personality disorder. Lastly, the limitations and advantages of the model are discussed.

Defense Mechanisms↗

PubMed2006

Mental chronometry of working memory retrieval: a combined functional magnetic resonance imaging and event-related potentials approach.

We used the combination of functional magnetic resonance imaging and event-related potentials to decompose the processing stages (mental chronometry) of working memory retrieval. Our results reveal an early transient activation of inferotemporal cortex, which was accompanied by the onset of a sustained activation of posterior parietal cortex. We furthermore observed late transient responses in ventrolateral prefrontal cortex and late sustained activity in medial frontal and premotor areas. We propose that these neural signatures reflect the cognitive stages of task processing, perceptual evaluation (inferotemporal cortex), storage buffer operations (posterior parietal cortex), active retrieval (ventrolateral prefrontal cortex), and action selection (medial frontal and premotor cortex). This is also supported by their differential temporal contribution to specific subcomponents of the P300 cognitive potential.

Adult↗

PubMed2005

High-frequency gamma-band activity in the basal temporal cortex during picture-naming and lexical-decision tasks.

Gamma-band activity (GBA) in electroencephalograms (EEGs) has been shown to reflect various cognitive processes. GBA has typically been recorded in the 30-60 Hz range in scalp EEGs. Recently, task-related "high GBA" (HGBA) with frequencies up to 100 Hz has been observed in studies with invasive electrocorticograms (ECoGs). In the present study, we recorded ECoGs from the bilateral basal temporal cortices in a patient with epilepsy and evaluated the task-related HGBA (most prominently in the 80-120 Hz range) accompanying picture-naming and lexical-decision tasks. We examined picture naming using two categories (line drawings of animals and tools). The lexical-decision task was performed using words and pseudowords of two distinct Japanese writing forms, kanji (morphograms) and kana (syllabograms). Task-related HGBA was observed bilaterally during the naming task. Recordings from some electrodes revealed significant differences in HGBA between animal and tool pictures. In contrast to the naming task, there was apparent left dominance in the lexical-decision task. Furthermore, significant differences in HGBA were observed between the Japanese kanji and kana words and between the kanji words and kanji pseudowords. A number of differences in the HGBA observed in the recordings from the basal temporal area were consistent with previous findings from neuroimaging and patient studies and suggest that HGBA is a good correlate of visual cognitive functions.

Acoustic Stimulation↗