Abstract
Iconic memory is a quickly decaying, fragile memory trace with a larger capacity than standard working memory (Sperling 1961). This transient visual memory buffer plays a key role in temporal integration (Nikolic et al 2009) and change detection (Urakawak et al 2010) and more generally in the consolidation of information into more durable forms. In addition, several recent studies have identified alpha-band (8-12 Hz) rhythmicity in behavioral performance when subjects are asked to detect a near-threshold visual stimulus (Fiebelkorn et al 2013, Laundau & Fries 2013). Here we asked if these rhythmic modulations in detection performance are due primarily to failures in initial sensory encoding or failures in iconic memory storage (and further consolidation). On each trial, we used a white full-field flash to reset the phase of alpha oscillations. We then briefly (25 ms) presented a circular target array of 8 letters at pseudo-randomly chosen timepoints ranging from 225 to 1400 ms after the reset flash. Finally, subjects were asked to report the 3 letters indicated by a post-cue occuring at delays of either 100, 400 or 1000 ms after target array presentation. Subjects recalled a significantly higher proportion of letters at short vs. long target-to-cue delays, replicating previous results in the iconic memory literature (Sperling, 1961). Furthermore, observed 10-14 Hz oscillations in behavioral performance were most prominent at the shortest target-to-cue delay interval. This is consistent with an influence of intrinsic alpha oscillations on information stored in high-capacity, but fragile, iconic memory.
Meeting abstract presented at VSS 2016