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Visual Condition (visual + condition)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Attention and Vigilance in Children with Down Syndrome

JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 6 2008
Kim L. Trezise
Background, Down syndrome (DS) has been the focus of much cognitive and developmental research; however, there is a gap in knowledge regarding sustained attention, particularly across different sensory domains. This research examined the hypothesis that children with DS would demonstrate superior visual rather than auditory performance on a sustained attention task and that this modality difference would not be seen in children with non-specific intellectual disability (NSID). Materials and Methods, Eleven children with DS and 16 children with NSID were compared on two versions of the sustained attention to response test (SART), varying only in presentation modality (visual or auditory). Errors of commission (failure to withhold response to target) and errors of omission (failure to respond to non-target distractors) were recorded. Results, Significant group differences were found in the visual modality and mental age was also found to effect error rates in the visual condition. No effect of group or mental age was observed in the auditory SART. Conclusions, Results suggest that, for individuals with DS, presentation of education material in a visual medium may facilitate sustained attention and thus learning. Further research using tools such as the SART to explore modality differences in sustained attention and additional cognitive domains is recommended. [source]

See no lies, hear no lies: differences in discrimination accuracy and response bias when watching or listening to police suspect interviews

APPLIED COGNITIVE PSYCHOLOGY, Issue 8 2008
Samantha Ann Mann
In the present experiment, police officers attempted to detect truths and lies told by suspects in their police interviews in three different ways: They either saw the suspects (visual condition), only heard the suspects (audio condition) or both saw and heard the suspects (control condition). Research has demonstrated that vocal and speech-related cues are better diagnostic cues to deceit than visual cues. Therefore, we predicted that participants in the visual condition would perform worst in the lie detection task. Having access only to visual cues may encourage observers to be more reliant on stereotypical beliefs when attempting to detect truths and lies. Since these stereotypes are related to the behaviour of liars, rather than to the behaviour of truth tellers, we further predicted that being exposed only to visual cues may result in a lie bias. The findings supported these hypotheses, and the implications are discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Rapid categorization of achromatic natural scenes: how robust at very low contrasts?

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2005
Marc J.-M.
Abstract The human visual system is remarkably good at categorizing objects even in challenging visual conditions. Here we specifically assessed the robustness of the visual system in the face of large contrast variations in a high-level categorization task using natural images. Human subjects performed a go/no-go animal/nonanimal categorization task with briefly flashed grey level images. Performance was analysed for a large range of contrast conditions randomly presented to the subjects and varying from normal to 3% of initial contrast. Accuracy was very robust and subjects were performing well above chance level (, 70% correct) with only 10,12% of initial contrast. Accuracy decreased with contrast reduction but reached chance level only in the most extreme condition (3% of initial contrast). Conversely, the maximal increase in mean reaction time was ,,60 ms (at 8% of initial contrast); it then remained stable with further contrast reductions. Associated ERPs recorded on correct target and distractor trials showed a clear differential effect whose amplitude and peak latency were correlated respectively with task accuracy and mean reaction times. These data show the strong robustness of the visual system in object categorization at very low contrast. They suggest that magnocellular information could play a role in ventral stream visual functions such as object recognition. Performance may rely on early object representations which lack the details provided subsequently by the parvocellular system but contain enough information to reach decision in the categorization task. [source]

Impaired modulation of the vestibulo-ocular reflex in Huntington's disease

MOVEMENT DISORDERS, Issue 1 2004
BSc(Hons), Joanne Fielding BA
Abstract The vestibulo-ocular reflex (VOR) stabilizes gaze during movement, in conjunction with other afferent information: visual, proprioceptive, and somaesthetic. The reflex can either be augmented or suppressed, depending on visual requirements, and undergoes long-term adaptation to compensate for physical changes in the subject. Importantly, over relatively short periods of time, the VOR should function consistently under the same circumstances. This study examines VOR function in patients with Huntington's disease (HD), with a view to investigating cortical influences on the reflex. Horizontal eye movements were recorded in 9 patients with HD and 7 normal subjects, using the scleral search coil technique, in response to high frequency, unpredictable head rotations imposed manually. To establish base VOR function, recordings were made in darkness, without instruction, before and after wearing ×2 magnifying lenses for a period of 2 hours to adapt the reflex. Recordings were also made before adaptation, while fixating a stationary visual target (VOR augmentation), and while fixating a target moving with the head (VOR suppression). Although results suggest that the VOR is preserved in HD, with relatively normal gain values and appropriate augmentation and suppression of the reflex with visual input, patients were unable to adapt the VOR to altered visual conditions. This represents a novel finding in HD and suggests that cortical structures compromised in HD exert influences on the long-term adaptation of the VOR. © 2003 Movement Disorder Society [source]