Memorable first impressions

Abstract

Our ability to recall details from a remembered image depends on a single mechanism that is engaged from the very moment the image disappears from view.

Keywords: delay encoding; human; iconic memory; neuroscience; population coding; short-term memory; temporal dynamics.

Figure 1.. Timeline of events during stimulus presentation and storage.

A visual stimulus (grey box containing pattern) with N items is presented for a period of time (pale blue region). Sensory activity increases to a maximum value during this period, and then decays when the stimulus disappears. For each item, VWM activity also increases towards an effective saturation limit, which is the maximum possible value divided by the number of items presented: here N=2, so the effective saturation limit is half the maximum possible value. When the target item is cued (black arrow; top) at a later time (yellow region), the non-target item(s) are removed from memory (grey trace), and activity associated with the target item (green trace) increases towards the maximum possible value. The level of activity (and hence the accuracy of memory recall) will vary more and more over time due to noise. VWM: visual working memory.