Abstract
It is well known that response inhibition (withholding a planned or initiated response) slows subsequent responses, but the exact mechanisms of this effect are not clear. Post-inhibition slowing can have real impacts on performance, so it is important to understand the cause(s). Currently, there are two hypothesized mechanisms: adjustments in general control settings and memory associations made between the inhibition and the stimulus. To examine these possibilities, we tested the time course of inhibition effects on visual search as the two mechanisms predict different patterns; a control adjustment predicts a short-lived, general effect while a memory association predicts a lasting, stimulus-specific effect. Data were obtained from the mobile app Airport Scanner (Kedlin Co., www.airportscannergame.com), a game in which players search simulated x-ray bags for prohibited items. On < 3% of trials, the passenger is an "Air Marshal" and therefore allowed to have a prohibited item, and players must withhold their response. This app offers a massive dataset (currently >2.8 billion trials), providing sufficient data to examine rare inhibition events and their aftereffects as far as 20 trials later. We assessed performance on search trials following either an Air Marshal trial (i.e., inhibition anchor) or a search trial (i.e., search anchor). To differentiate between control setting and memory association accounts of inhibition, we compared stimulus switches, wherein the inhibition anchor and the trial of interest (lags 1-20) had different targets, and stimulus repetitions, wherein the inhibition anchor and the trial of interest had the same target. A brief negative effect was of inhibition on performance was observed during stimulus switches, consistent with adjustments in control settings. A prolonged negative effect was observed during stimulus repetitions, consistent with a memory association account. The results suggest that both memory associations and control settings influence behavior following response inhibition, but on distinct time scales.
Meeting abstract presented at VSS 2017