Examining Overt and Covert Attentional Capture by Task Irrelevant Stimuli during a Novel Continuous Performance Task

Abstract

Paradigms used to examine attentional capture are limited by the presentation of stimuli that are not entirely task irrelevant. Moreover, attentional capture has rarely been studied in the context of continuous task performance. Consequently, it is not possible to measure the duration of the distractor interference effect while participants are continuously engaging in a task. These limitations represent important obstacles to existing paradigms as they do not reflect the type of entirely irrelevant, spontaneous distraction that occurs when individuals are continuously engaging in daily life tasks. To address these limitations, we implemented a new methodology based on a paradigm designed by Forster and Lavie (2011). Participants worked through a 12-item circular array making consecutive forced choice responses as to whether the identity of an item was a letter or a digit. On thirty percent of the trials, a distracting colorful cartoon character image was presented in the center of the circular display. Participants were instructed to respond as quickly and accurately as possible to the identity of the items until they had responded to the last item in the array. Moreover, we tracked the participants’ eye movements throughout the entirety of the task. Response times (RTs) to the items immediately following the presentation of a distractor were significantly slower than RTs to items when no distractor was presented. Importantly, the distractor’s effect on RTs was maintained over three responses following distractor presentation, providing evidence for lasting attentional capture by entirely irrelevant distractors. Despite this prolonged interference effect, there was no evidence of overt oculomotor capture over these three responses, suggesting that distraction by entirely irrelevant distractors is covert. These findings are important as they provide further evidence for the ability of distractors presented with abrupt onsets to capture attention despite participants having no attentional set for these distractor stimuli.