Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Perceptual Disorders”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 613 records · Page 34Linked to original sources
PubMedDate not supplied

Inflated perception of responsibility for harm in obsessive-compulsive disorder.

The present study examined the proposition that inflated responsibility is implicated in obsessive compulsive disorder (OCD). Compared to non-anxious control participants (NACs), and an anxious control group with generalized social phobia (GSPs), we predicted that individuals with OCD (OCs) would exhibit a greater urge to rectify situations involving potential risk, would report more distress upon leaving such situations unrectified, and would feel more personal responsibility if the unrectified situations resulted in harm. Fifteen OCs, 15 NACs, and 15 GSPs completed the Obsessive Compulsive Responsibility Scale (OCRS), which included low-risk, OC-relevant, and high-risk situations. Compared to NACs and GSPs, OCs reported more urges, distress, and responsibility in low-risk and OC-relevant situations; no group differences were detected on high-risk situations. GSPs and NACs differed only in their responsibility in OC-relevant situations, with GSPs reporting higher responsibility than controls. Our results suggest that compared to OCs, NACs, and GSPs can better differentiate between situations that merit concern and ones that do not.

Adult↗
PubMed2001

Visual and visuospatial development in young children with Williams syndrome.

This study investigated the relation between sensory visual problems and the severity of visuospatial difficulties in a large group of young children with Williams' syndrome (WS). A questionnaire describing visual and associated problems was completed by the families of 108 children with WS and detailed follow-up assessments were conducted, including visual, spatial, motor, visuocognitive, and linguistic tests of 73 of these children (mean age 7 years 3 months; 40 males, 73 females). Children with WS showed a much higher incidence of common paediatric sensory vision problems (strabismus, visual acuity loss, amblyopia, reduced stereopsis) than normally developing children. It was found that delays with respect to age normative values increased with age on all tests. No significant correlation was found between the presence of a visual deficit and the severity of the visuospatial problems, suggesting that the difficulties children with WS have in understanding spatial arrangements are not simply a result of their earlier sensory visual problems. Results confirm the dissociation between visuospatial and language abilities in children with WS, and support the neurobiological model of a split between ventral and dorsal stream processing of visual information with a generalized deficit in dorsal stream processing in young children with WS.

Amblyopia↗
PubMed1999

Relation between clinical measures and fine manipulative control in children with hemiplegic cerebral palsy.

The present investigation examines the relation between various clinical measures and the performance of a functional precision grip-lift task. Fifteen children with hemiplegic cerebral palsy (CP), aged 8 to 14 years, and 15 age-matched control children grasped and lifted an object whose surface texture was varied while their fingertip forces were recorded. The force coordination was compared with tactile sensibility, grip strength, manual dexterity, and spasticity using correlational and regression analyses. The findings highlight the importance of tactile sensibility in this task. However, the manner in which sensibility was related varied for the sensory adaptation of fingertip forces, the anticipatory scaling of the force increase, and the smooth transitions between the temporal phases comprising the grip-lift task. The findings also indicate that spasticity affects some measures of the task, but not others, suggesting that the relation between spasticity and motor performance may not be absolute. The results further suggest that the impairments in grasping in children with hemiplegic CP are largely but not exclusively due to disturbed sensory mechanisms which may have direct implications for therapeutic intervention.

Adolescent↗
PubMed2000

The frontal aging hypothesis evaluated.

That the human frontal lobes are particularly vulnerable to age-related deterioration has been frequently invoked as an explanation of functional decline in aging. This "frontal aging hypothesis" is evaluated in this review by examining evidence of selectively reduced frontal lobe function in aging. The frontal aging hypothesis predicts that functions largely dependent on frontal regions would decline in aging, while functions largely independent of frontal lobes would remain relatively spared. The hypothesis further predicts that age-related brain change would selectively impact frontal regions. The literatures on working memory, visuospatial attention, face recognition, and implicit memory were reviewed as exemplars of functions dependent on prefrontal, parietal, temporal and occipitotemporal cortices, respectively, with a view to establishing mediating structures and effects of aging. Age sensitivity was seen both in functions dependent on frontal integrity as well as in functions apparently independent of frontal integrity. Further, although prefrontal areas exhibit age-related decreases in regional volume, blood flow and metabolism, nonfrontal cortical regions undergo similar declines. It is concluded that while the frontal lobes are subject to age-related changes reflected in both behavior and pathology, there is only weak and conflicting evidence that frontal regions are selectively and differentially affected by aging. It is argued that a network-based theory of cognitive aging has advantages over the localizationist approach inherent in the frontal aging hypothesis.

Aged↗
PubMed2003

Left hippocampal volume loss in Alzheimer's disease is reflected in performance on odor identification: a structural MRI study.

The very high sensitivity and specificity of odor identification tasks in discriminating between Alzheimer's patients and normals suggests that they reflect the presence of underlying neuropathology. Significant neuropathological changes are seen in areas critical to processing olfactory information, even in the early stages of Alzheimer's disease (AD). The current study was designed to investigate whether performance on olfactory tasks (odor threshold and odor identification) was related to volumetric MRI measures of mesial temporal areas central to olfactory information processing and important in the neuropathology of AD. Participants were 8 male and 5 female patients with probable AD, and 10 male and 12 female normal age-matched controls, diagnosed at the UCSD Alzheimer's Disease Research Center. The study investigated correlations between volumetric measures of hippocampus, the parahippocampal gyrus and the amygdala, and the psychophysical measures of olfactory function. Robust relationships were observed between mesial temporal lobe volumes and olfactory functional measures. The finding of a strong relationship between left hippocampal volume and performance on the odor identification task (r = .85) is compatible with a left-hemisphere superiority for verbally mediated olfactory tasks. The findings suggest a neural substrate for the breakdown in functional performance on verbally mediated odor identification tasks in Alzheimer's disease and suggest the utility of quantitative MRI measures and psychophysical performance in the assessment of AD. These results support the potential clinical utility of inclusion of odor identification tests in diagnostic batteries for detecting AD.

Aged↗
PubMedDate not supplied

The unilateral spatial neglect phenomenon in patients with arteriovenous malformations of deep brain structures.

Clinical-neuropsychological investigations were performed in 187 patients with arteriovenous malformations (AVM) of deep brain structures; 28 had AVM of the caudate nucleus, 35 of the thalamus, 45 of the cingulate gyrus, 43 of the hippocampus, and 36 of the corpus callosum. A total of 47 patients displayed neglect phenomena of different modalities, while unfixed neglect was demonstrated in 40 cases using special tests. The vast majority of patients showed neglect of left-sided space and the left side of the body, while only three patients showed right-sided neglect. These three patients had signs of left-handedness. In the development of neglect in all patients was associated with post-hemorrhagic or post-operative damage to the white matter (the projections of sensory bundles of the parietal and occipital lobes, the periventricular white matter) or the thalamus and corpus callosum. In hemispheric lesions, neglect developed on the background of the corresponding derangements (hemihypesthesia hemianopsia) and were of the same modality. In cases of damage to the corpus callosum, neglect could develop without accompanying sensory disturbances or the phenomenon could occur on different sides (in cases of simultaneous left hemisphere damage). This supports the independent nature of the neglect phenomenon.

Brain↗
PubMed1998

Olfaction in persons with Alzheimer's disease.

The need for low cost, noninvasive procedures for aiding in the diagnosis and understanding of Alzheimer's Disease (AD) has led to theories and procedures examining the role of olfactory disorders because of the finding that the brains of AD patients invariably exhibit neuropathology in the hippocampus and entorhinal cortex. This loss correlates with the increase in the number of plaques and tangles and with the severity of dementia. Considered together, these findings suggest that brain structures closely related to the olfactory system demonstrate significant histopathology in AD. A comprehensive review of the literature pertaining to olfaction in persons with AD revealed that the olfactory identification ability of patients with memory disorders is impaired relative to controls. Consistency is lacking, however, when olfactory detection thresholds are investigated. Also, there is inconsistency in regards to severity of illness and olfactory function. In addition to differentiating AD patients from normals, the olfactory paradigm has shown some limited usefulness in differentiating AD patients from some other demented patients.

Aged↗
PubMed2004

An exploration of causes of non-literal language problems in individuals with Asperger Syndrome.

Individuals with Asperger Syndrome (AS), a high functioning variant of Autism, are often noted to possess intact language ability, yet fail to use this language capacity to engage in interactive communication. This difficulty using language in a social context has been referred to as a deficit in pragmatic language. In particular, difficulty understanding nonliteral language devices, such as irony has been observed. This paper examines the veracity of two theories that have attempted to explain the causes of pragmatic language difficulties in individuals with Asperger Syndrome; the theory of Weak Central Coherence (WCC) and Social Inference theory. Fourteen young adults with AS and 24 age-matched controls were assessed on cognitive tasks measuring WCC processes, social inference or Theory of Mind ability, and the ability to interpret ironic remarks. Results indicated that the ability to understand the belief states of others is critical to understanding ironic language in AS.

Adolescent↗
PubMed2001

Neuropsychological functioning in chronic fatigue syndrome: a review.

OBJECTIVE: In this paper we review critically the current status of neurocognitive studies in patients with chronic fatigue syndrome (CFS). METHOD: CFS literature was monitored as part of a large research project which involved several neuropsychological and psychopathological studies. The literature survey was the result of several consecutive searches on Medline and PsycInfo databases. RESULTS: The neurocognitive studies are reviewed in terms of scientificaly accepted aspects of attention and memory. In addition, we review possible explanations for cognitive dysfunction in CFS. This is preceded with a discussion of the methodological limitations that are considered to explain inconcistencies across neuropsychological studies in CFS. CONCLUSION: The current research shows that slowed processing speed, impaired working memory and poor learning of information are the most prominent features of cognitive dysfunctioning in patients with CFS. Furthermore, to this date no specific pattern of cerebral abnormalities has been found that uniquely characterizes CFS patients. There is no overwhelming evidence that fatigue is related to cognitive performance in CFS, and researchers agree that their performance on neuropsychological tasks is unlikely to be accounted solely by the severity of the depression and anxiety.

Attention↗
PubMed1993

Cognitive therapy of anxiety disorders.

A review of studies of cognitive-behavioral therapy (CBT) for generalized anxiety disorder, panic disorder with and without agoraphobia, and social phobia indicates that CBT is consistently more effective than waiting-list and placebo control groups. In general, CBT has proved more beneficial than supportive therapy as well. Comparisons with active behavioral treatments provide more variable results. Converging evidence suggests that cognitive change may be a strong predictor of treatment outcome, but that such change may be produced by a number of therapeutic approaches. Pretest-posttest change with CBT is depicted in meta-analytic summary form for each disorder.

Agoraphobia↗
PubMed2000

Partial hippocampal inactivation: effects on spatial memory performance in aged and young rats.

Changes in anatomical or functional connectivity during normal aging are thought to contribute to cognitive alterations over the lifespan. Neural network theories predict that synaptic loss in an aging brain could place the organism near the point of dysfunction in the nonlinear curve defining neural compromise versus performance. The present experiments examined whether aged rats are closer to this point of behavioral dysfunction by reversibly inactivating one or both hippocampal hemispheres. As expected, bilateral tetracaine inactivation of the hippocampus disrupted spatial memory in both age groups. Unilateral left hippocampal inactivation significantly increased errors only in aged rats; however, unilateral inactivation of the right hippocampus had no effect. The present outcome could reflect more extensive synaptic dysfunction in the aged right hippocampus or a greater involvement of the left hippocampus in spatial working memory problems.

Age Factors↗
PubMed1998

Neurocognitive deficit in schizophrenia: a quantitative review of the evidence.

The neurocognitive literature on test performance in schizophrenia is reviewed quantitatively. The authors report 22 mean effect sizes from 204 studies to index schizophrenia versus control differences in global and selective verbal memory, nonverbal memory, bilateral and unilateral motor performance, visual and auditory attention, general intelligence, spatial ability, executive function, language, and interhemispheric tactile-transfer test performance. Moderate to large raw effect sizes (d > .60) were obtained for all 22 neurocognitive test variables, and none of the associated confidence intervals included zero. The results indicate that schizophrenia is characterized by a broadly based cognitive impairment, with varying degrees of deficit in all ability domains measured by standard clinical tests.

Attention↗
PubMed1998

Outcome of closed head injury in Malaysian children: neurocognitive and behavioural sequelae.

OBJECTIVES: To compare the neurobehavioural outcome of children aged 6-12 years with severe closed head injury [sCHI] (coma > 24 h), mild-to-moderate head injury [mCHI] (coma < 6 h) and orthopaedic controls. METHODS: Twenty-nine children in each group, matched for age, sex and ethnicity, were assessed using the Glasgow outcome Scale (GOS), Weschler Intelligence Scale for Children (WISC-III), Movement Assessment Battery for Children (Movement ABC), Wide Range Assessment of Learning and Memory (WRAML) and a standardised neurological examination 6 months post-injury. Parental reporting of pre- and post-injury behaviour was documented using the Child Behaviour Checklist (CBCL). RESULTS: Seven (24.1%) children with sCHI and three (10.3%) orthopaedic controls had residual motor deficits. Three (10.3%) children with sCHI and none in the other groups faced problems with independent ambulation. Twenty-seven (93.1%) of those with sCHI and all children in the other groups had GOS scores of good recovery or moderate disability. Twenty-two (81.5%) sCHI, five (18.5%) mCHI and one (3.7%) orthopaedic control reported a deterioration in school performance. MANOVAS identified a significant injury group effect for performance skills (P = 0.007), verbal skills (P = 0.002), memory and learning (P = 0.001) and motor skills (P = 0.001). Repeated measures ANOVA for pre- and post-injury CBCL scores showed significant differences related to somatic complaints (P = 0.004), problems of socialising (P = 0.003), delinquency (P = 0.004), aggressiveness (P = 0.010), thought (P < 0.001) and attention (P < 0.001). Post-hoc univariate analysis showed the significant differences were between that of the sCHI children and the other two groups. CONCLUSION: Although most sCHI children seemed to have made good physical recovery, there were cognitive, motor, memory and learning difficulties and behavioural problems concomitant with a deterioration in school performance compared with those with lesser or no head injury. This highlights the need for better integrated rehabilitation services to enable a gradual return into mainstream school.

Achievement↗
PubMed2003

The impact of right subcortical lesions on executive functions and spatio-cognitive abilities: a case study.

Deep-seated cerebral lesions have been known to cause various cognitive impairments. In order to study the impact of these lesions on cognitive functioning, in particular on executive functions and spatial abilities, an investigation was carried out on a right-handed patient with lesions in the subcortical structures of the right hemisphere. Findings revealed a complex pattern of neuropsychological impairments that included a memory deficit, neglect and anosognosia. In addition, there was a severe executive function syndrome. Finally, observations show impairments in spatial abilities, usually attributed to right parietal damage. There was no obvious language deficit. The pattern of deficits was interpreted as a disconnection syndrome.

Adult↗
PubMed2006

Amygdalohippocampal involvement in tinnitus and auditory memory.

CONCLUSION: The preliminary results suggest that in chronic unilateral tinnitus the contralateral amygdalohippocampal complex does seem to be involved in tinnitus perception of pure tones. OBJECTIVES: Functional neuroimaging studies have revealed that the hippocampus and amygdala are involved in tinnitus perception. The amygdala and hippocampus are supplied by the anterior choroidal artery. Selective amobarbital injections in the anterior choroidal artery result in a non-functional amygdalohippocampal area for 10 min. The aim of this study was to assess the influence of this procedure on tinnitus perception. PATIENTS AND METHODS: Amobarbital (80 mg in total) was injected selectively in two sessions in the left and right anterior choroidal artery in six male patients with tinnitus: four with unilateral tinnitus, two with bilateral tinnitus. Of the patients with unilateral tinnitus, three had right-sided tinnitus and one had left-sided tinnitus. The average age was 57.3 years (range 43-69). Average tinnitus duration was 5.3 years (range 1-10). The differences in visual analogue scale (VAS) scores before and after the amytal tests were analysed. RESULTS: Amytal injection ipsilateral to the side where the tinnitus was perceived resulted in a maximum of 30% tinnitus suppression, whereas amytal injection contralateral to the tinnitus side yielded a 60-70% tinnitus suppression in three patients with unilateral chronic tinnitus (>4 years). Only pure tone tinnitus was suppressed, white noise was not. Two patients with bilateral tinnitus had no suppression, irrespective of the tinnitus type. A third patient without clinical tinnitus suppression had tinnitus of more recent origin (1.5 years).

Adult↗