Motivational influences on response inhibition measures.
Citation: Leotti, L. A., Wager, T. D. (2010). Motivational influences on response inhibition measures. Journal of Experimental Psychology: Human Perception and Performance, 36(2): 430-47.
Psychological research has placed great emphasis on inhibitory control due to its integral role in normal
cognition and clinical disorders. The stop-signal task and associated measure--stop-signal reaction time
(SSRT)--provides a well-established paradigm for measuring response inhibition. However, motivational
influences on stop-signal performance and SSRT have not been examined. We conceptualize the
stop-signal paradigm as a decision-making task involving the trade-off between fast responding and
accurate inhibition. In 4 experiments, we demonstrate that performance trade-offs are influenced by
inherent motivational biases and explicit strategic control. As a result, SSRT was lower when participants
favored correct stopping over fast responding than when the same participants favored fast responding
over correct stopping. We present a novel variant of the stop-signal task that uses monetary incentives
to manipulate motivated speed-accuracy trade-offs. By sampling performance at multiple-trade-off
settings, we obtain a measure of inhibitory ability that is independent of trade-off bias, and thus, more
easily interpretable when comparing across participants. We present a working theoretical model to
explain the effects of motivational context on response inhibition.