According to the authors of a study from Manchester, United Kingdom, 'Previous studies have demonstrated that the retention of information in short-term visual perceptual memory can be disrupted by the presentation of masking stimuli during interstimulus intervals (ISIs) in delayed discrimination tasks (S. Magnussen & W. W. Greenlee, 1999). We have exploited this effect in order to determine to what extent short-term perceptual memory is selective for stimulus color.'
'We employed a delayed hue discrimination paradigm to measure the fidelity with which color information was retained in short-term memory. The task required 5 color normal observers to discriminate between spatially non-overlapping colored reference and test stimuli that were temporally separated by an ISI of 5 s. The points of subjective equality (PSEs) on the resultant psychometric matching functions provided an index of performance. Measurements were made in the presence and absence of mask stimuli presented during the ISI, which varied in hue around the equiluminant plane in DKL color space. For all reference stimuli, we found a consistent mask-induced, hue-dependent shift in PSE compared to the 'no mask' conditions. These shifts were found to be tuned in color space, only occurring for a range of mask hues that fell within bandwidths of 29-37 deg. Outside this range, masking stimuli had little or no effect on measured PSEs. The results demonstrate that memory masking for color exhibits selectivity similar to that which has already been demonstrated for other visual attributes,' wrote V.A. Nemes and colleagues, Manchester Royal Eye Hospital (see also Vision Research).
The researchers concluded: 'The relatively narrow tuning of these interference effects suggests that short-term perceptual memory for color is based on higher order, non-linear color coding.'
Nemes and colleagues published their study in the Journal of Vision (The retention and disruption of color information in human short-term visual memory. Journal of Vision, 2012;12(1):400-413).
For more information, contact V.A. Nemes, Manchester Royal Eye Hospital, Vis Sci Center, Manchester M13 9WH, Lancs, United Kingdom.
Publisher contact information for the Journal of Vision is: Assoc Research Vision Ophthalmology Inc, 12300 Twinbrook Parkway, Rockville, MD 20852-1606, USA.
Keywords: City:Manchester, Country:United Kingdom, Region:Europe, Vision Research
This article was prepared by Health & Medicine Week editors from staff and other reports. Copyright 2012, Health & Medicine Week via NewsRx.com.
