Abstract
Change blindness occurs when there are not enough attentional resources to detect a change on an unattended object. A series of experiments were conducted using a dual-task design to examine the time course of change detection process and consequent attentional demands for VWM. Subjects remembered colors of four squares. After a memory delay, another four colored squares were displayed as a test array. Subjects reported if there was any color change in the test array compared to the memory array. While performing the central VWM task, subjects also monitored a sudden abrupt color change among a number of squares displayed at periphery. As the squares at periphery were being displayed without any offset, the abrupt color change was supposed to be perceptually salient. We varied the onset of peripheral change i) at 200ms after the memory array of the central task showed up ii) at the same time as the offset of the memory array, iii) at 500ms after memory array onset, iv) at the same time as the onset of the test array, v) at 48ms after the test array showed up. When subjects only performed the peripheral change detection task alone, the change detection accuracy was above 90%. However, the peripheral change detection became relatively inaccurate when performed together with the central task. The pattern of impairment was only evident if the peripheral change occurred around the onset of memory items for the central task. The performance however was gradually improved through memory delay interval, and was fully recovered around the onset of test items. These results indicate that the early phase of change for consolidating and maintaining memory items into VWM needs more attentional resources than the late phase of change detection in which the memory items are compared against test items.
Meeting abstract presented at VSS 2012