Rapid but incomplete degradation of residual visual representations over time.

Abstract

While visual working memory has a short lifetime, residual representations can persist and disrupt currently maintained information. This phenomenon is known as proactive interference (PI), and the present study investigated whether the representations underpinning item-specific PI lose details over time. This would be expected if the memories underlying PI are susceptible to temporal processes such as decay, which is strongly disputed. In four experiments, a modified version of the recent probes task was used, requiring participants to determine whether a probe matched one of two recently presented targets. The probe sometimes matched an untested target from a previous trial, or varied in its resemblance to it, and the amount of time separating trials varied. Results revealed that PI was specific and highly disruptive at very short intervals, but its effect diminished over time. At longer intervals, a milder form of PI was present and produced by probes that were only similar to a recently encountered target. In summary, residual visual representations may remain accurate for a few seconds after encoding, before losing precise details and continuing to endure in an inexact state.