PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cognitive Reflection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

Motion sickness susceptibility and solution choice in a pragmatic paradox.

This paper reports on an experiment which employed a classic paradox, known as the 'prisoner's dilemma', to explore possible differences in problem solving preference across a spectrum of motion sickness susceptibility. A mathematical form of the problem was used in which the subject was asked to imagine playing a game without communicating with his hypothetical partner. There were three possible solutions to the problem, a win-win, a lose-lose, and a win-lose solution. The results support the contention that a cognitive bias exists across a spectrum of motion sickness susceptibility, highly motion sick individuals having a greater tendency to pick the solution which allows both participants to win. This bias runs counter to that which might be expected on the basis of personality traits (non-motion sick individuals are more socially involved), and suggests that the cognitive tendency may reflect basic problem-solving strategies rooted in orientation process. The potential implications of these findings are discussed.

Dominance, Cerebral↗

P3-specific amplitude reductions to respiratory and auditory stimuli in subjects with asthma.

The respiratory-related evoked potential (RREP) is the electroencephalographic response to brief inspiratory occlusion. The P3 component of the response reflects the active cognitive processing of stimulus information. This study investigated the RREP in 16 subjects with asthma and 16 control subjects. In addition, auditory-evoked potentials were recorded using an oddball paradigm in both groups and were compared with the RREP results. Perceptual sensitivity was assessed using a load magnitude estimation task, whereby subjects estimated the magnitude of four added resistive loads using a modified Borg scale. For RREP assessment, inspiratory occlusions were presented for 200 milliseconds. For auditory-evoked potential assessment, 1,000- and 2,000-Hz pure tones were presented at 60 dB for 100 milliseconds, with the 2,000-Hz tone presented with 20% probability and identified as a target stimulus. Scalp electroencephalographic activity was measured from 29 channels. Resistive load intensity was linearly related to magnitude estimation in both subjects with asthma (r2 = 0.96) and control (r2 = 0.99) subjects. Results showed that both the respiratory and auditory P3 components were markedly reduced in the group with asthma compared with the control group. Other components were similar between the groups. These results suggest an intrinsic reduction in P3 amplitude for patients with asthma, which may relate to differences in processing perceptual information.

Adolescent↗

Learning and memory in combat veterans with posttraumatic stress disorder.

OBJECTIVE: The authors investigated a broad range of memory functions for stimuli unrelated to trauma to determine whether symptoms such as intrusive memories might reflect an underlying cognitive deficit unrelated to the psychological content of the traumatic memory in patients with posttraumatic stress disorder (PTSD). METHOD: The authors measured the intellectual functioning of 20 male combat veterans with PTSD and 12 normal comparison subjects using the WAIS and evaluated them for performance on memory using the California Verbal Learning Test. RESULTS: Veterans with PTSD showed normal abilities in the functions of initial attention, immediate memory, cumulative learning, and active interference from previous learning. However, these veterans showed a circumscribed cognitive deficit, manifested by the presence of substantial retroactive interference and revealed by a significant decrement in retention following exposure to an intervening word list. CONCLUSIONS: The data suggest that patients with PTSD may have fairly specific deficits in the monitoring and regulation of memory information.

Adult↗

The effects of methylphenidate on neural systems of attention in attention deficit hyperactivity disorder.

OBJECTIVE: Recent studies have suggested that attention deficit hyperactivity disorder (ADHD) is associated with abnormalities in basal ganglia and prefrontal cortical functioning. However, these studies have primarily relied upon cognitive tasks that reflect impulse control rather than attentional mechanisms. METHOD: The authors used functional magnetic resonance imaging to investigate the neural correlates of selective and divided attention in a randomized, double-blind, placebo-controlled pharmacological challenge with methylphenidate in 15 adolescents with ADHD (ages 14-17), eight adolescents with reading disorder (ages 12-17), and four adolescents with both reading disorder and ADHD (ages 14-18) who were scanned during both a methylphenidate and a placebo session. Fourteen healthy comparison subjects (ages 12-20) who were not given methylphenidate served as the primary comparison group. RESULTS: During the divided attention task, unmedicated subjects with ADHD or reading disorder recruited the left ventral basal ganglia significantly less than the healthy comparison subjects. Methylphenidate led to an increase in activation in this region but had no effect on task performance. Subjects with ADHD also recruited the middle temporal gyrus significantly less than the comparison subjects, but methylphenidate did not have a direct effect on activation in this region. CONCLUSIONS: These results suggest that ADHD is associated with abnormal processing in attentional networks, with specific dysfunction in striatal circuitry. Methylphenidate may act to normalize activity within this network.

Adolescent↗

Narrative incoherence in schizophrenia: the absent agent-protagonist and the collapse of internal dialogue.

It is widely known that people with schizophrenia have difficulty telling a coherent story of their lives and that this is linked to impoverished function. But what specifically has gone wrong in the narratives in schizophrenia? Is it the case that some elements of narrative remain intact in schizophrenia while others are uniquely affected? To address these questions, we qualitatively analyze the personal narratives of three persons with schizophrenia, which have emerged in psychotherapy. Based on this analysis we suggest that narratives in schizophrenia uniquely fail to situate agency within the narrator resulting in a story that is missing an agent-protagonist. While the narratives we present contain coherent accounts of how others are connected to one another, they fail to evolve into a story about the self as an agent that others could associate with the narrator. We speculate that this may reflect neuro-cognitively based difficulties maintaining the internal dialogue that propels agency as well as fears that any emergent subjectivity may be appropriated or objectified by others. Implications for psychotherapy are discussed.

Adult↗

Self-reports are not related to objective assessments of cognitive function and sedation in patients with cancer pain admitted to a palliative care unit.

Cancer patients often report complaints of cognitive impairment and sedation. It is not well known if subjective complaints reflect objective assessments of cognitive function (CF) and sedation. We obtained self-reports of sedation and CF from 29 patients admitted to a palliative care unit and receiving morphine treatment. Sedation was reported on a verbal rating scale (VRS) and CF was reported using the EORTC QLQ-C30 health-related quality-of-life questionnaire CF scale. The self-reports were compared with objective assessments of sedation and CF by applying the Observer's Assessment of Alertness/Sedation (OAA/S) scale and Mini Mental State Examination (MMS), respectively. The assessments were repeated for seven patients who were readmitted to the palliative care unit. The patient self-reports of memory, concentration and sedation were dichotomized into noncomplainers and complainers. The percentages of complainers were 54%, 46% and 37% for memory, concentration and sedation, respectively. Patients who complained from difficulties with concentration or memory did not score differently from noncomplainers on objective assessments of CF (MMS score), but had a significantly higher level of fatigue. Patients complaining from sedation did not score differently from noncomplainers on objective assessments of sedation (OAA/S score). We observed no significant correlations between EORTC QLQ-C30 CF scale scores and MMS scores, or between VRS sedation scores and OAA/S scores. The study demonstrates a lack of relationship between patient self-reports and objective methods for assessing sedation and cognitive failure. This finding illustrates the importance of differentiating between observations and patient self-reports. The results also question the validity of patient self-reports for measurements of cognitive failure and sedation.

Adult↗

Out of contact, out of mind: the distributed nature of the self.

A truly remarkable aspect of human existence is the unitary sense of self that exists across time and place. Understanding the nature of self-what it is and what it does-has challenged scholars since antiquity. How can empirical research measure what it is to have a sense of self? We propose that the sense of self may emerge from the functions of a left hemisphere "interpreter". First, we examine evidence for the existence of self-processing mechanisms in the intact brain, from behavioral and functional neuroimaging research. The available evidence suggests that the sense of self is widely distributed throughout the brain. Second, we discuss these findings in relation to what is known about higher cognitive functions in humans who have undergone a surgical procedure to sever the connection between the two cerebral hemispheres. Split-brain research has facilitated an understanding of the way in which each cerebral hemisphere independently processes information. Research in this area has shown that each cerebral hemisphere features distinct information-processing capabilities. This cognitive asymmetry is reflected in the notion of a left hemisphere interpreter module which, we have argued, generates a unitary sense of consciousness even in the disconnected brain. This chapter describes how this interpreter may also give rise to a unified sense of self.

Brain↗

Tolerance for ambiguity and self-actualization.

This study was designed to test the hypothesis, implicit in several areas of previous research, that high tolerance for ambiguity is a cognitive style which reflects high levels of underlying psychological health. Using Self-Actualization scores on the Tennessee Self Concept Scale, 36 adult subjects were defined as relatively high or low in self-actualization with equal numbers of males and females in each group. All subjects then performed individually on the Rorschach test and the Rorschach protocols were rated reliably for degree of tolerance for ambiguity. It was found that regardless of sex the high self-actualization group exhibited a significantly higher level of tolerance for ambiguity than the low self-actualization group. The finding was interpreted as confirmation of the study's hypothesis.

Journal Article↗

Effects of Abeta immunization (AN1792) on MRI measures of cerebral volume in Alzheimer disease.

BACKGROUND: Alzheimer disease (AD) is characterized by progressive cerebral atrophy that may be measured using MRI. Reported are MRI findings of a Phase IIa immunotherapy trial in AD prematurely terminated owing to meningoencephalitis in a subset of patients. OBJECTIVE: To assess cerebral volume changes in patients immunized with AN1792 (beta-amyloid [Abeta] 1 to 42) who were antibody responders (anti-AN1792 IgG titer of > or =1:2,200) compared with placebo patients. METHODS: This randomized, multicenter, placebo-controlled, double-blind trial of AN1792 225 mug plus QS-21 50 mug included 372 patients with probable AD. Patients received one to three injections of AN1792/QS-21 or saline and were assessed for 12 months. Volumetric MRI was performed pre dose and at month 12 or early termination. Brain, ventricular, and hippocampal volume changes were measured from registered scan pairs. RESULTS: Two hundred eighty-eight patients had paired scans (mean interval 10.9 months). Antibody responders (n = 45) had greater brain volume decrease (3.12 +/- 1.98 vs 2.04 +/- 1.74%; p = 0.007), greater ventricular enlargement as a percentage of baseline brain volume (1.10 +/- 0.75 vs 0.48 +/- 0.40%; p < 0.001), and a nonsignificant greater hippocampal volume decrease (3.78 +/- 2.63 vs 2.86 +/- 3.19%; p = 0.124) than placebo patients (n = 57). Increased losses in brain volume were not reflected in worsening cognitive performance; a composite z score across a Neuropsychological Test Battery showed differences favoring antibody responders over placebo (0.03 +/- 0.39 vs -0.24 +/- 0.45; p = 0.008). CONCLUSIONS: A dissociation between brain volume loss and cognitive function was observed in AN1792/QS-21 antibody responders. The reasons for this remain unclear but include the possibility that volume changes were due to amyloid removal and associated cerebral fluid shifts.

Aged↗

Iowa cochlear implant clinical project: results with two single-channel cochlear implants and one multi-channel cochlear implant.

Cochlear implants have become a realistic alternative for the management of profoundly deaf patients. A variety of implants with differing electrode designs and coding strategies have been developed by nine major implant centers around the world. Each center has their "star" patient, but objective comparisons between these different implant designs are unavailable. In order to determine the performance characteristics of the present generation of cochlear implants, comparison data are vital. We have developed an independent center where uniform objective comparisons of different cochlear implants can be performed longitudinally. This report will present results of nine patients implanted with three different cochlear implant prostheses. Four patients have been implanted with the Los Angeles (House) single-channel implant, three patients have received the Vienna (Hochmair) single-channel intracochlear device, and two patients have been implanted with the Melbourne (Clark) 21-channel unit. All patients have had 11 months or more of experience with their cochlear prostheses. The results of a comprehensive audiologic battery which includes audiovisual and environmental tasks are presented. All implants provide significant improvement in speechreading and sound awareness. The findings to date suggest that there is strong correlation between top-down cognitive processing (as reflected by lip reading skills) and performance with cochlear implants.

Adult↗

Research on the clinical usefulness of the Rorschach: 2. The assessment of cerebral dysfunction.

A review of research on the use of the Rorschach in the assessment of cerebral dysfunction indicated that the Rorschachs of patients with cerebral dysfunction do not manifest any characteristic response in terms of percentages, ratios, or any unique response to any one of the stimulus determinants of the blots (color, shading, the stimulus for movement). The patient with cerebral dysfunction does manifest a unique style of thinking; responses tend to be concrete, perseverative, and stereotypic. This finding is similar to that found with schizophrenics where research, summarized by Frank in 1990, also indicated no uniquely 'objective' response style but reflected a unique cognitive style. These two reviews taken together suggest that the better way to use Rorschach data in clinical work is as an opportunity to assess patients' thinking as opposed to the Rorschach being used as a psychometric device, yielding 'numbers.'

Brain Damage, Chronic↗

Visuomotor performance in children with infantile nephropathic cystinosis.

Infantile nephropathic cystinosis is a genetic metabolic disorder in which the amino acid cystine accumulates in various organs, including the kidney, cornea, thyroid, and brain. Despite normal intellect, individuals with cystinosis may have specific impairments in the processing of visual information. To examine further the specific types of deficits in visual processing found in individuals with cystinosis, we administered the Development Test of Visual-motor Integration to 26 children with cystinosis (4 to 16 yr. old) and 26 matched controls. The cystinosis group achieved a significantly lower standard score, raw score, and mean ceiling than did the control group. Qualitative analyses showed that in the cystinosis group, size within errors and rotation errors were more prevalent than in the control group. Correlational analyses showed that with advancing age, the cystinosis subjects tended to fall further behind their chronological age. Our data, together with the findings of previous studies, suggest that the visuospatial difficulties in children with cystinosis may be due to inadequate perception or processing of visually presented information. Furthermore, the increasing discrepancy with age may reflect a progressive cognitive impairment, possibly as a result of cystine accumulation in the brain over time.

Adolescent↗

Cognitive functioning, family history of alcoholism, and antisocial behavior in female polydrug abusers.

Family history of alcoholism and antisocial behaviour had both independent and synergic negative relationships with abstract verbal reasoning for a group of 42 female polydrug abusers whose main drug was heroin. This finding suggests that the observed lower cognitive performance may reflect the family history of alcoholism or antisocial behaviour rather than just drug abuse and is consistent with theories predicting a relative deficiency in high language skill by persons with antisocial personality disorders.

Adult↗

Medical and psychology students' disbelief in the inheritance of risk factors for suicide.

Despite convergent evidence for a role of genetic risk factors for suicide stemming from quantitative genetic (family, twin, and adoption designs), molecular genetic, and geographical studies, professionals, likely to be exposed to suicide, appear to disbelieve strongly in the inheritance of risk factors for suicide. In a sample of 1,093 Austrian medical and psychology students, about 80% of respondents did not endorse genetic risk factors for suicide, regardless of their sex, age bracket, field and year of study, and overall knowledge on suicide facts. This may reflect educational gaps, cognitive biases against genetic bases and explanations, or both. One single implication is that this information needs to be incorporated and covered more visibly in medical and psychology textbooks and curricula.

Adult↗

Contributions of hippocampal cellular damage and NMDA receptor dysfunction to behavioral markers of schizophrenia.

Pathological changes in the hippocampal formation have been noted in schizophrenic patients and manipulation of neurochemical functions within the limbic system has been shown to yield behavioral changes consistent with schizophrenia. The present study evaluated the impact of kainic acid induced hippocampal cellular damage and manipulation of NMDA receptor function (agonism and antagonism) on common behavioral markers of schizophrenia (habituation and prepulse inhibition of the acoustic startle response in rats). Cellular damage significantly impaired habituation and NMDA antagonism disrupted prepulse inhibition. Damage induced impairment of habituation is consistent with effects on latent inhibition (which is also unaffected by NMDA antagonism) while the antagonist disruption of prepulse inhibition is consistent with effects on associative plasticity. The current findings provide further support for a diverse neurobiological substrate of schizophrenic symptoms suggesting that pharmacologic intervention may need to be multifaceted and could involve competing mechanisms. Cognitive impairments may reflect diminished NMDA receptor function whereas positive symptoms may reflect heightened engagement of anatomically disturbed cellular elements.

Animals↗

Optical and neural factors limiting acuity development: evidence obtained from a monkey model.

Infants have much poorer acuity than adults. Recent experiments with infant monkeys indicate that this poor acuity cannot be explained on the basis of optics (quality of the retinal image) or sampling frequency (inter-receptor spacing). On the other hand, the poor acuity is not just a reflection of immature cognitive or motor development. Rather, the development of adult acuity levels appears to depend on maturation of neural elements in the early stages of the visual system.

Adult↗

Psychopathology in Dutch and American heroin addicts.

The Beck Depression Inventory (BDI) and the Symptom Check List-90 (SCL-90) were administered to 47 Dutch and 121 American White male heroin addicts receiving methadone. A one-way MANOVA indicated that the Dutch and American samples displayed comparable SCL-90 profiles, but that the Dutch had more symptom complaints than the Americans. The mean BDI total score of the Dutch was higher than that of the Americans, and this mean difference reflected more severe cognitive and affective symptoms in the Dutch than in the Americans. There was no difference between the samples with respect to somatic and performance symptoms. Furthermore, the mean levels of symptoms distress for the nine SCL-90 subscales reported by both the Dutch and the American heroin addicts were comparable to those of American psychiatric outpatients.

Adult↗

Semantic-pragmatic disorder: a right hemisphere syndrome?

Following right hemisphere lesions, adults' speech can become copious and inappropriate, with abnormal prosody, and they may be unable to comprehend metaphor or humour. Their symptoms resemble those of children with semantic-pragmatic language disorder, who use fluent, grammatically complex language, but with poor sensitivity to the communicative situation. The hyperlexia found in some of these children reflects an underlying cognitive problem in integrating semantic information with knowledge of the world. Both groups of patients fail comprehend inferential meaning or to make use of paralinguistic features. It is hypothesised that the disorders of communication and cognition found in semantic-pragmatic language disorder may be linked to right hemisphere dysfunction, but this has yet to be confirmed by research.

Autistic Disorder↗