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PubMed1999

Poor perception of nonverbal social-emotional cues in relatives of schizophrenic patients.

The present study compared nonverbal social perception in relatives of schizophrenic patients (n = 21) with that of normal controls (n= 19). We hypothesized that relatives would display deficits in social perception and we sought to determine the skills that are associated with this deficit. Relatives performed significantly worse than controls on the Profile of Nonverbal Sensitivity Test (PONS), despite comparable performance on skills hypothesized to be related to nonverbal social perception: visual perception, nonverbal problem solving, facial recognition, facial affect recognition, naming, social judgment, and vigilance. To further explore the relationships among these skills, we calculated correlations between the PONS score and associated skills separately within both the relative and control groups and assessed whether the values of these correlations differed between groups. Correlations that differed significantly indicated a greater association, within relatives, between slower reaction times on vigilance tasks and poor PONS performance. Further research is needed to clarify the nature of this relationship, to better characterize social perception deficits in relatives, and to determine whether these perceptual deficits are part of the genetic diathesis to schizophrenia.

Adult↗
PubMed1996

Neuropsychological functioning in a patient with paraneoplastic limbic encephalitis.

A 54-year-old woman with clinically diagnosed paraneoplastic limbic encephalitis secondary to adenocarcinoma of the lung is described. Neuropsychological evaluation revealed intact visual perception, visual construction, language, speeded processing, and verbal abstract reasoning in the presence of a severe anterograde amnesia for both verbal and visual information. A profound consolidation problem is discussed in view of other diseases of the mesial temporal lobes resulting in impaired consolidation of new material.

Adenocarcinoma↗
PubMed1998

Hearing impairment, emotions and audiological rehabilitation: a sociological perspective.

Encounters are one of the basic dynamics of society, although this does not imply that macro-phenomena do not have ontological status. Encounters involve interaction and hence communication, and interaction and communication generate emotions. Emotions are of great significance to our well-being. Disturbed communication is by far the most commonly reported effect of hearing loss and many handicaps resulting from hearing impairment are of an emotional character. Following Goffman and Scheff I argue that fear of losing face is crucial in interaction, and that shame is an important emotion. Shame is often hidden, misnamed or avoided. But if shame is acknowledged, it is discharged. In traditional audiological rehabilitation, the focus is aural perception, visual perception and speech. I contend that emotional problems, like shame and embarrassment, have to be brought to the fore, the focus less on the compensatory side of rehabilitation and more on the acceptance and coping sides.

Affect↗
PubMed1991

Chronic occupational exposure to manganese and neurobehavioral function.

Comprehensive examinations of neurobehavioral function were performed in two groups of workers with chronic exposure to industrial manganese, and two control groups. Group 1 included 17 exposed workers without parkinsonism while Group 2 consisted of four exposed workers with parkinsonian syndrome resulting from chronic manganese poisoning. Group 3 was composed of eight idiopathic parkinsonian patients while Group 4 included 19 control subjects. Age, sex, and educational level of these four groups were matched. The neuropsychological battery consisted of tests of orientation, intelligence, learning and memory, language and communication, visuospatial and visual perception, visual attention, manual dexterity, and information processing speed. There was no evidence of neurobehavioral impairment in the non-parkinsonian workers whereas impaired general intelligence, visuoperceptive impairment and defective manual dexterity, as well as slowdown in response speed were manifested in the parkinsonian workers.

Adult↗
PubMedDate not supplied

Neuropsychological assessment of an 8-year-old child following excision of a right temporal lobe oligodendroglioma.

A case of right temporal lobe oligodendroglioma in an 8-year-old female is reported. This case is unusual, because of the rarity of this type of tumour in children, because it was accompanied by seizure activity which is atypical, and because it highlights the difficulties in diagnosis. Prior to diagnosis, the background had included normal early development, followed by gradual development of partial complex seizures with poor response to medication in the absence of clear findings on EEG or CT. Considered to have been present prior to 1 year of age, the tumour was purported to be the aetiological base for seizure activity, which ceased after surgical excision. Post-surgical difficulties with academic progress and behaviour resulted in referral for neuropsychological evaluation, which revealed lowered overall cognitive functioning with deficits in processing speed, abstract verbal reasoning, concept formation, visual perception, visual reasoning, scanning, attention, memory, academic attainment and learning, and clerical motor speed. Behavioural functioning revealed impairment in social skills, irritability, impulsivity, and mood changes. The relative contributions of medication (adverse reaction and toxicity), long term seizure activity, early age of onset, and presence/excision of tumour are difficult to ascertain specifically. Findings appear consistent with those of right temporal lobe brain injury.

Brain Neoplasms↗
PubMed1996

A motor signal and "visual" size perception.

Recent models of the visual system in primates suggest that the mechanisms underlying visual perception and visuomotor control are implemented in separate functional streams in the cerebral cortex. However, a little-studied perceptual illusion demonstrates that a motor-related signal representing arm position can contribute to the visual perception of size. The illusion consists of an illusory size change in an afterimage of the hand when the hand is moved towards or away from the subject. The motor signal necessary for the illusion could be specified by feedforward and/or feedback sources (i.e. efference copy and/or proprioception/kinesthesis). We investigated the nature of this signal by measuring the illusion's magnitude when subjects moved their own arm (active condition, feedforward and feedback information available), and when arm movement was under the control of the experimenter (passive condition, feedback information available). Active and passive movements produced equivalent illusory size changes in the afterimages. However, the illusion was not obtained when an after-image of subject's hand was obtained prior to movement of the other hand from a very similar location in space. This evidence shows that proprioceptive/kinesthetic feedback was sufficient to drive the illusion and suggests that a specific three-dimensional registration of proprioceptive input and the initial afterimage is necessary for the illusion to occur.

Afterimage↗
PubMed2000

Touch can change visual slant perception.

The visual system uses several signals to deduce the three-dimensional structure of the environment, including binocular disparity, texture gradients, shading and motion parallax. Although each of these sources of information is independently insufficient to yield reliable three-dimensional structure from everyday scenes, the visual system combines them by weighting the available information; altering the weights would therefore change the perceived structure. We report that haptic feedback (active touch) increases the weight of a consistent surface-slant signal relative to inconsistent signals. Thus, appearance of a subsequently viewed surface is changed: the surface appears slanted in the direction specified by the haptically reinforced signal.

Biofeedback, Psychology↗
PubMed2002

Dynamic visual speech perception in a patient with visual form agnosia.

To examine the role of dynamic cues in visual speech perception, a patient with visual form agnosia (DF) was tested with a set of static and dynamic visual displays of three vowels. Five conditions were tested: (1) auditory only which provided only vocal pitch information, (2) dynamic visual only, (3) dynamic audiovisual with vocal pitch information, (4) dynamic audiovisual with full voice information and (5) static visual only images of postures during vowel production. DF showed normal performance in all conditions except the static visual only condition in which she scored at chance. Control subjects scored close to ceiling in this condition. The results suggest that spatiotemporal signatures for objects and events are processed separately from static form cues.

Adult↗
PubMedDate not supplied

Handwriting difficulties in primary school children: a search for underlying mechanisms.

OBJECTIVE: This study investigated the contribution of perceptual-motor dysfunction and cognitive planning problems to the quality or speed of handwriting in children with handwriting problems (HWP). METHOD: Twenty-nine children with HWP and 20 classroom peers attending regular schools (grade 2 and grade 3) were tested with regard to visual perception, visual-motor integration, fine motor coordination, and cognitive planning abilities. RESULTS: The HWP group scored significantly lower on visual perception, visual-motor integration, fine motor coordination, and cognitive planning in comparison with classroom controls. Regression analyses showed that visual-motor integration was the only significant predictor for quality of handwriting in the HWP group, whereas fine motor coordination (i.e., unimanual dexterity) was the only significant predictor of quality of handwriting in the control group. CONCLUSIONS: Results suggest that two different mechanisms underlie the quality of handwriting in children with and without handwriting problems. Poor quality of handwriting of children with HWP seems particularly related to a deficiency in visual-motor integration.

Child↗
PubMedDate not supplied

Vision, visual-information processing, and academic performance among seventh-grade schoolchildren: a more significant relationship than we thought?

OBJECTIVE: To compare visual and visual-information processing skills between children with and without mild reading and academic problems and examine the incidence of visual deficits among them. METHOD: Seventy-one seventh graders classified as proficient (n = 46) and nonproficient (n = 25) readers were compared with respect to scores on an accepted vision screening, on tests of visual-perception, visual-motor integration, and academic performance. Further, academic performance and visual-information processing were compared between children who failed and passed the vision screening. RESULTS: Visual deficits were found in 68% of the participants, and among significantly more boys than girls. Nonproficient readers had significantly poorer academic performance and vision-screening scores than the proficient readers. Participants who passed the visual screening performed significantly better in visual perception than those who failed. CONCLUSION: Visual function significantly distinguishes between children with and without mild academic problems, as well as on visual-perception scores. The high occurrence of visual deficits among participants warrants consideration of vision deficits among schoolchildren with academic performance difficulties.

Achievement↗
PubMed2005

Auditory-visual speech perception and auditory-visual enhancement in normal-hearing younger and older adults.

OBJECTIVE: The purpose of the present study was to examine the effects of age on the ability to benefit from combining auditory and visual speech information, relative to listening or speechreading alone. In addition, the study was designed to compare visual enhancement (VE) and auditory enhancement (AE) for consonants, words, and sentences in older and younger adults. DESIGN: Forty-four older adults and 38 younger adults with clinically normal thresholds for frequencies of 4 kHz and below were asked to identify vowel-consonant-vowels (VCVs), words in a carrier phrase, and semantically meaningful sentences in auditory-only (A), visual-only (V), and auditory-visual (AV) conditions. All stimuli were presented in a background of 20-talker babble, and signal-to-babble ratios were set individually for each participant and each stimulus type to produce approximately 50% correct in the A condition. RESULTS: For all three types of stimuli, older and younger adults obtained similar scores for the A condition, indicating that the procedure for individually adjusting signal-to-babble ratios was successful at equating A scores for the two age groups. Older adults, however, had significantly poorer performance than younger adults in the AV and V modalities. Analyses of both AE and VE indicated no age differences in the ability to benefit from combining auditory and visual speech signals after controlling for age differences in the V condition. Correlations between scores for the three types of stimuli (consonants, words, and sentences) indicated moderate correlations in the V condition but small correlations for AV, AE, and VE. CONCLUSIONS: Overall, the findings suggest that the poorer performance of older adults in the AV condition was a result of reduced speechreading abilities rather than a consequence of impaired integration capacities. The pattern of correlations across the three stimulus types indicates some overlap in the mechanisms mediating AV perception of words and sentences and that these mechanisms are largely independent from those used for AV perception of consonants.

Acoustic Stimulation↗
PubMed1993

Counterexample to the hypothesis of functional similarity between tactile and visual pattern perception.

In earlier work, the author has demonstrated that tactile pattern perception and visual pattern perception exhibit many parallels when the effective spatial resolution of vision is reduced to that of touch, thus supporting the hypothesis that the two pattern senses are functionally similar when matched in spatial bandwidth. The present experiments demonstrate a clear counterexample to this hypothesis of functional similarity. Specifically, it was found that the lateral masking effect of a surround on tactile character recognition increases when the surround changes in composition from solid lines to dots, whereas for vision, recognition performance goes in the opposite direction. This finding necessitates some modification of the model of character recognition proposed by the author (Loomis, 1990) as it applies to the sensing of raised tactile patterns. One possible modification would be to incorporate, as the initial stage of pattern transformation, the continuum mechanics model for the skin that was developed by Phillips and Johnson (1981b).

Adult↗
PubMed2005

Audio-visual speech perception off the top of the head.

The study examined whether people can extract speech related information from the talker's upper face that was presented using either normally textured videos (Experiments 1 and 3) or videos showing only the outlined of the head (Experiments 2 and 4). Experiments 1 and 2 used within- and cross-modal matching tasks. In the within-modal task, observers were presented two pairs of short silent video clips that showed the top part of a talker's head. In the cross-modal task, pairs of audio and silent video clips were presented. The task was to determine the pair in which the talker said the same sentence. Performance on both tasks was better than chance for the outline as well as textured presentation suggesting that judgments were primarily based on head movements. Experiments 3 and 4 tested if observing the talker's upper face would help identify speech in noise. The results showed the viewing the talker's moving upper head produced a small but reliable improvement in speech intelligibility, however, this effect was only secure for the expressive sentences that involved greater head movements. The results suggest that people are sensitive to speech related head movements that extend beyond the mouth area and can use these to assist in language processing.

Auditory Perception↗