Figure 1.

Experiment 1 task paradigm, stimulus configurations, and behavioral results. A) Participants viewed a fixation cross (300 ms) and then were given an arrow cue (200 ms) indicating the side of the screen to which they should covertly attend during the trial. A variable interval (300–400 ms) preceded the memory array (100 ms) containing one of the four conditions displayed above. The experimental conditions included stimulus displays including either two items (2-UG), three items (3-UG), three items grouped by similarity and weak proximity (3-SWP), or three items grouped by similarity and strong proximity (3-SSP). After a delay-period (900 ms), a probed item appeared that was either the same color (“old” trials) that was originally presented or is a different color (“new” trials). Participants were given 3 seconds to respond. Note that stimuli are depicted for illustrative purposes only and do not reflect the exact dimensions and visual angles of the stimuli displayed during the actual experiment. B–C) The abscissa depicts the conditions being compared while accuracy (proportion correct) is plotted along the ordinate. B) Overall VWM performance in Experiment 1. C) VWM performance based on the two probe types for trials from both the three object similarity + weak proximity condition and the three object similarity + strong proximity, which could have been a colored square that was grouped or ungrouped during stimulus presentation. In panels B and C, asterisks symbolize an observed significant difference between various conditions; α = p < 0.05. Error bars represent the standard error of the mean in each condition.