Comparing imagery and perception: Using eye movements to dissociate mechanisms in search

It has been demonstrated that color imagery can have a profound impact when generated prior to search, while at the same time, perceptual cues have a somewhat limited influence. Given this discrepancy, the present study evaluated the processes impacted by imagery and perception using a singleton search task where participants had to find an oddball colored target among homogenously colored distractors. Prior to each trial, a perceptual color was displayed or imagery was generated that could match the target, distractors, or neither item in the search array. It was revealed that color imagery led to both a larger benefit when it matched the target and a larger cost when it matched the distractors relative to perceptual cues. By parsing response times into pre-search, search, and response phases based on eye movements, it was revealed that, while imagery and perceptual cues both influenced the search phase, imagery had a significantly greater influence than perceptual cues. Further, imagery influenced pre-search and response phases as well. Overall, the present findings reveal that the influence of imagery is profound as it affects multiple processes in the vision-perception pipeline, while perception only appeared to impact search.