Abstract
A visual change in VWM-based change detection was reported to resemble a salient pop-out in visual search (Hyun et al, 2009). To explore the nature of such efficient detection of a visual change, we compared the detection of a VWM-perception mismatch against a sensory mismatch driven by two concurrent binocular inputs. In the present study, participants wore a pair of shutter-glass goggles and viewed two identical sets of colored boxes (setsize 2, 4, 6) displayed respectively to each individual eye. The binocular sets of boxes were perceived as a single coherent array of colored boxes, and their colors were asked to be remembered. The memory array was then followed by a test array consisting of another set of binocularly-displayed colored boxes. In half of trials, the test array was exactly the same as the memory array (i.e., change-absent trials) whereas potentially evoked two types of a change in the remaining half (i.e., change-present trials): Half of change-present trials had an identical color change across corresponding boxes in both binocular test items (i.e., both-change trials) while the remaining half had a color change in either of the binocular test items (i.e., either-change trials). The results showed the proportion of "change" responses in both- and either-change conditions was fairly large and comparable to each other when the setsize was 2 and 4. However, when the setsize was 6, the proportion in both-change condition decreased substantially compared to either-change condition, leading to an apparent lack of sensitivity to the change only in both-change condition. These results indicate a VWM-perception mismatch can pop-out as strongly as a binocular sensory mismatch unless VWM-capacity is challenged, and further suggest the phenomenological experience of detecting a supra-threshold visual change presumably resembles the sensation of automatic detection of a sensory conflict across two simultaneous perceptual inputs.
Meeting abstract presented at VSS 2013