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At least 1,423 records · Page 79Linked to original sources
PubMed1989

School achievement in treated PKU children.

Phenylketonuric children who were treated early and maintained a pherestricted diet through age 10 were compared with those who discontinued the diet after age 6 on a standardized test of intelligence, school achievement, language and perceptual skills. Mean IQ, reading and spelling test scores improved between ages 6 and 10 for the on-diet children in comparison to those who were off-diet. However, mean scores on arithmetic, language and perceptual skills declined at a uniform rate for both groups. Children with PKU scored significantly lower than did their non-PKU siblings on tests of visual perception and visual-motor skills. Because the school years, particularly, the early teens, pose increased stress in affected PKU individuals, it is recommended that dietary restriction at least through the high school years is prudent for their optimal physical, mental, emotional and educational growth.

Achievement↗
PubMed1989

Effects of chronic alcoholism on perception of hierarchical visual stimuli.

Visuospatial processing in chronic alcoholism was investigated by asking subjects to make similarity judgements of hierarchically constructed visual stimuli. Comparison figures were similar to a standard figure at the global or local level. Alcoholics were less influenced by the global patterns in their similarity judgements than were controls. On the WAIS-R Block Design subtest, alcoholics were also more likely than controls to distort the outer configuration of the design. Results indicate that alcoholism affects global processing on both experimental visuoperception tasks and on clinical measures of visuospatial ability. Implications for models of alcoholic dysfunction are discussed.

Adult↗
PubMed2003

Effect of semicircular canal stimulation on the perception of the visual vertical.

UNLABELLED: The subjective visual vertical (SVV) is usually considered a measure of otolith function. Herewith we investigate the influence of semicircular canal (SCC) stimulation on the SVV by rotating normal subjects in yaw about an earth-vertical axis, with velocity steps of +/- 90 degrees /s, for 60 s. SVV was assessed by setting an illuminated line to perceived earth vertical in darkness, during a per- and postrotary period. Four head positions were tested: upright, 30 degrees backward (chin up) or forward, and approximately 40 degrees forward from upright. During head upright/backward conditions, a significant SVV tilt (P < 0.01) in the direction opposite to rotation was found that reversed during postrotary responses. The rotationally induced SVV tilt had a time constant of decay of approximately 30 s. Rotation with the head 30 degrees forward did not affect SVV, whereas the 40 degrees forward tilt caused a direction reversal of SVV responses compared with head upright/backward. Spearman correlation values (Rho) between individual SCC efficiencies in different head positions and mean SVV tilts were 0.79 for posterior, 0.34 for anterior, and - 0.80 for horizontal SCCs. Three-dimensional video-oculography showed that SVV and torsional eye position measurements were highly correlated (0.83) and in the direction opposite to the slow phase torsional vestibuloocular reflex. IN CONCLUSION: 1) during yaw axis rotation without reorientation of the head with respect to gravity, the SVV is influenced by SCC stimulation; 2) this effect is mediated by the vertical SCCs, particularly the posterior SCCs; 3) rotationally induced SVV changes are due to torsional ocular tilt; 4) SVV and ocular tilts occur in the "anticompensatory," fast phase direction of the torsional nystagmus; and 5) clinically, abnormal SVV tilts cannot be considered a specific indication of otolith system dysfunction.

Acceleration↗
PubMed2006

[Visually impaired teenagers: perceptions on sexuality].

This exploratory-descriptive study aimed to reveal perceptions of visually impaired teenagers on their sexuality. Data was collected from May to June 2004 by means of semistructured interviews, carried out with eight visually impaired teenagers studying at an institution in Porto Alegre, Brazil. The collected information was analyzed through content analysis according to Bardin. Two main categories emerged: Sexuality and Socio-behavioral changes. The research participants lack information on various sexuality-related issues, such as: knowledge on physiology, anatomy, affection and preventive care. Health professionals, especially nurses, need to be prepared to deal with these issues and to contribute to the development of a healthy sexuality of these individuals.

Adolescent↗
PubMed2000

The role of the saccade target object in the perception of a visually stable world.

Although the proximal stimulus shifts position on our retinae with each saccade, we perceive our world as stable and continuous. Most theories of visual stability implicitly assume a mechanism that spatially adjusts perceived locations associated with the retinal array by using, as a parameter, extra-retinal eye position information, a signal that encodes the size and direction of the saccade. The results from the experiment reported in this article challenge this idea. During a participant's saccade to a target object, one of the following was displaced: the entire scene, the target object, or the background behind the target object. Participants detected the displacement of the target object twice as frequently as the displacement of the entire background. The direction of displacement relative to the saccade also affected detectability. We use a new theory, the saccade target theory (McConkie & Currie, 1996), to interpret these results. This theory proposes that retinal (as opposed to extra-retinal) factors, primarily those concerning the saccade target object, are critical for the detection of intrasaccadic stimulus shifts.

Fixation, Ocular↗
PubMed1996

The influence of LCD shutter glasses on spatial perception in stereoscopic visualization.

For a general establishment of stereoscopic visualisation systems in clinical routine a fundamental analysis of the influence of technical, optical and physiological parameters onto visual spatial perception seems to be necessary to achieve an optimisation of the existing devices. As one important component of these systems we perform studies on the influence of LCD Shutter glasses on the individual binocular perception. The developed shutter system, the initial experiments and their results are presented.

Computer Simulation↗
PubMedDate not supplied

[Neuropsychological deficits in hydrocephalus associated spina bifida].

INTRODUCTION. The term spina bifida is used to describe a large number of abnormalities in which the common denominator is incomplete posterior fusion of the vertebral arches. DEVELOPMENT. Spina bifida, as a congenital alteration affecting closure of the neural tube frequently appears in relation to hydrocephaly. The object of this article is to review the neuropsychological alterations which occur in hydrocephaly, with special reference to hydrocephaly linked to spina bifida. The authors suggest consideration of these alterations in view of the new models of cognitive neuropsychology. The commonest alterations are those affecting visual-perceptive and visual-constructive function, working memory, pragmatic use of language and executive functions.

Humans↗
PubMed1976

Neuropsychological testing following head injuries: prosopagnosia without visual field defect.

Assessment of residual cerebral dysfunction in the post-traumatic patient poses considerable problems particularly when the neurological examination yields minimal or equivocal findings. The clinical picture is frequently complicated by emotional disturbance not easily differentiated from "post-traumatic neurosis." This report describes such a patient whose disorder was elicidated by neuropsychological testing. Numerous studies have established the validity of neuropsychological tests particularly when they are interpreted by psychologists specifically trained in their use. These procedures are also useful in differentiating patients with neurologic complaints of a nonorganic etiology from patients with similar complaints secondary to confirmed brain lesions. Although the findings reported here pertain to a patient exhibiting a rare neurologic consequence of closed head injury, the methods employed are applicable to subtle behavioral manifestations of diverse etiologies. Neurophyshological findings in a patient unable to recognize faces of familiar persons (prosopagnosia) disclosed a severe impairment of visual perception despite intact visual acuity and fields. The prosopagnosia was also associated with a pervasive memory deficit without dementia. Our results challenge current concepts of prosopagnosia and support the need for neuropsychological evaluation of post-traumatic patients.

Black or African American↗
PubMed1987

Psychoeducational findings among children treated for phenylketonuria.

Early treated phenylketonuric children who maintained a phe-restricted diet through age 10 were compared with those who discontinued the diet after age 6 on standardized tests of intelligence, school achievement, language, and perceptual skills. Mean IQ, reading, and spelling test scores improved between ages 6 and 10 for the on-diet children in comparison to those who were off diet. Mean scores on arithmetic, language, and perceptual skills, however, declined at a uniform rate for both groups. Children with PKU scored significantly lower than did their non-PKU siblings on tests of visual perception and visual-motor skills. We conclude that children with PKU should be maintained on a phe-restricted diet.

Achievement↗
PubMed2006

Visual neglect after right posterior cerebral artery infarction.

OBJECTIVES: To investigate the characteristics and neuroanatomical correlates of visual neglect after right-sided posterior cerebral artery (PCA) infarction. METHODS: 15 patients with acute PCA strokes were screened for the presence of neglect on a comprehensive battery of cognitive tests. Extra tests of visual perception were also carried out on six patients. To establish which areas were critically associated with neglect, the lesions of patients with and without neglect were compared. RESULTS: Neglect of varying severity was documented in 8 patients. In addition, higher-order visual perception was impaired in 5 of the 6 patients. Neglect was critically associated with damage to an area of white matter in the occipital lobe corresponding to a white matter tract connecting the parahippocampal gyrus with the angular gyrus of the parietal lobe. Lesions of the thalamus or splenium of the corpus callosum did not appear necessary or sufficient to cause neglect, but may mediate its severity in these patients. CONCLUSIONS: PCA stroke can result in visual neglect. Interruption of the white matter fibres connecting the parahippocampal gyrus to the angular gyrus may be important in determining whether a patient will manifest neglect.

Aged↗
PubMed2004

Evidence against a central bottleneck during the attentional blink: multiple channels for configural and featural processing.

When a visual target is identified, there is a period of several hundred milliseconds when the processing of subsequent targets is impaired, a phenomenon labeled the attentional blink (AB). The emerging consensus is that the identification of a visual target temporarily occupies a limited attentional resource that is essential for all visual perception. The present results challenge this view. With the same digit discrimination task that impaired subsequent letter discrimination for several hundred milliseconds, we found no disruption of subsequent face discrimination. These results suggest that all stimuli do not compete for access to a single resource for visual perception. We propose a multi-channel account of interference in the AB paradigm.

Attention↗
PubMedDate not supplied

[Visuo-perceptual processing in patients with schizophrenia treated with typical or atypical antipsychotics].

OBJECTIVE: This is a pilot study exploring the possible association between a particular antipsychotic (AP) medication regime and both clinical and visuo-perceptual features. SUBJECTS AND METHOD: A series of 32 patients (25 males; mean age+/- SD = 28.1+/- 5.1 years, range 20-39) suffering from schizophrenia for at least two years (mean+/- SD duration of illness = 6.0+/- 3.6 years), and maintained on the same antipsychotic medication for at least one year, were divided into four groups according to their maintenance medication. Their assessment included the Positive and Negative Syndrome Scale (PANSS), the Rey's Complex Figure test (visual perception and memory), and Leff's BELS scale (skills of daily living). RESULTS: There were not significant differences in demographic features or daily living skills. The patients on oral classical APs scored significantly higher on the disorganization factor than those on clozapine. In general, patients on atypical APs did better on the visual perception and memory tasks, with those on fluphenazine decanoate being the poorest. In the whole series of the 32 patients, the copy time increased with age, with higher scores on the negative and the depressive factors, and with lower scores in visual memory. On multiple linear regression, only visual memory score and age remained significant. CONCLUSIONS: In spite of the small sample size, patients on atypical APs seem to be in a better condition, both in symptoms and in visuo-spatial abilities. Visual reproduction is influenced by both visual memory and age.

Activities of Daily Living↗