An initial ‘snapshot’ of sensory information biases the likelihood and speed of subsequent changes of mind

Abstract

We often need to rapidly change our mind about perceptual decisions in order to account for new information and correct mistakes. One fundamental, unresolved question is whether information processed prior to a decision being made (‘pre-decisional information’) has any influence on the likelihood and speed with which that decision is reversed. We investigated this using a luminance discrimination task in which participants indicated which of two flickering greyscale squares was brightest. Following an initial decision, the stimuli briefly remained on screen, and participants could change their response. Using psychophysical reverse correlation, we examined how moment-to-moment fluctuations in stimulus luminance affected participants’ decisions. This revealed that the strength of even the very earliest (pre-decisional) evidence was associated with the likelihood and speed of later changes of mind. To account for this effect, we propose an extended diffusion model in which an initial ‘snapshot’ of sensory information biases ongoing evidence accumulation.

Neural correlates of confidence during decision formation in a perceptual judgment task

“…If the extent of evidence accumulation at the time of the first-order choice varies across confidence judgments (as specified in racing accumulator models), then the fixed decision boundary assumption of many postdecisional locus models is false. If this is the case, it is likely that (at least part of) the variance captured by postdecisional processes in these models is due to processes that occur during the first-order judgment (e.g., Turner et al, 2022). To account for this, hybrid decisional/postdecisional process models could be developed to better delineate the consequences of computations occurring over each time window.…”

“…Our results also do not challenge the idea that, in some cases, decision reversals and confidence judgments can be substantively influenced by continued evidence accumulation, even without stimuli being presented between the choice and confidence rating. For example, changes of mind can be driven by stimuli that appear during (and immediately before) motor action execution, where these stimuli do not influence the first-order decision (e.g., Resulaj et al, 2009; Turner et al, 2022). However, we note that, in our dataset and most existing work involving difficult perceptual discrimination tasks, there is no clear evidence of covariation between Pe component amplitudes and confidence as would be expected from a substantial influence of postdecisional evidence accumulation.…”