Been around the block: The sustained influence of efficacy on cognitive effort allocation over time

Vollständiger Abstract

Worum geht es in dieser Arbeit?

Abstract Background Modern accounts of cognitive effort posit that it is actively controlled based on a cost-benefit analysis, integrating (subjective) costs and possible rewards, which is furthermore moderated by efficacy (i.e., whether there is a clear relationship between successful task performance and reward). Although there is evidence that reward and efficacy interact, this relationship may not be stable over time, given that reward attenuates time-on-task effects while efficacy’s relationship with time-on-task is still unclear. Methods Thirty participants performed a Stroop task with a block design, with block-wise manipulation of efficacy (possible rewards were either contingent upon correct task performance or determined without regard to task performance) and reward (high or low). Behavioral measures (response time and accuracy), pupil data (tonic and phasic pupil size), and blink measures (rate and duration) were recorded and analyzed using a mixed-effects modelling approach, with each block split into two halves to assess time-on-task effects. Results The behavioral data showed clear effects for efficacy, a pattern that was also largely mirrored in phasic pupil size, suggesting substantial effort allocation. In contrast, we found no clear impact of time-on-task or reward on behavioral data or phasic pupil size. Tonic pupil size and blink metrics (rate and duration) did suggest time-on-task effects, with reward and efficacy attenuating these in some cases. However, because these time-on-task effects diverged from behavioral outcomes and yielded theoretically ambiguous interaction patterns, they warrant cautious interpretation. Conclusions These findings support the role of efficacy in effort-related cost-benefit calculations, even when efficacy information is sustained across relatively long task blocks. More broadly, the present study highlights the interpretive complexity of ocular measures for studying cognitive effort over time.