Choice History Biases Subsequent Evidence Accumulation

Abstract

Perceptual choices depend not only on the current sensory input, but also on the behavioral context. An important contextual factor is the history of one's own choices. Choice history often strongly biases perceptual decisions, and leaves traces in the activity of brain regions involved in decision processing. Yet, it remains unknown how such history signals shape the dynamics of later decision formation. Models of perceptual choice construe decision formation as the accumulation of sensory evidence towards decision bounds. In this framework, it is commonly assumed that choice history signals shift the starting point of accumulation towards the bound reflecting the previous choice. We here present results that challenge this idea. We fit a bounded accumulation ('drift diffusion') decision model to behavioral data from multiple perceptual choice tasks and sensory modalities, and estimated bias terms that dependent on observers' previous choices. Individual history biases in behavior were consistently explained by a history-dependent change in the evidence accumulation, rather than in its starting point. Choice history signals thus seem to affect the interpretation of current sensory input, akin to shifting endogenous attention towards (or away from) the previously selected interpretation.

Boosting Brain Signal Variability Underlies Liberal Shifts in Decision Bias

“…We note, however, that quenching and rising of neural variability should not be mutually exclusive concepts, but can in principle occur simultaneously if one considers the different timescales in which these phenomena seem to occur: shorter scales (< 40 ms) for quenching and longer scales (> 40 ms) for rising variability. Future studies could further explore how neural variability quenching and rising in different timescales are related to various aspects of decision making, such as perceptual sensitivity, different kinds of bias (29)(30)(31), but also confidence and metacognitive processes (32,33). Finally, individual decision bias has also been linked to the magnitude of transient dilations of the eye's pupil (34,35), suggesting a link between pupil-linked neuromodulation (36) and neural variability (5).…”

Response outcomes gate the impact of expectations on perceptual decisions

“…The probability of a subject to repeat the previous response (Fig. 7a) is a common measure to characterize history effects (Abrahamyan et al, 2016;Urai et al, 2018) . By dissecting the distinct contribution of both first-and second-order serial biases (Gokaydin et al, 2011;Jones et al, 2013;Meyniel et al, 2016;Wilder et al, 2009) , i.e.…”

Action enhances predicted touch

“…These different kinds of bias can be dissociated in computational models that conceptualise perceptual decisions as a process of evidence accumulation. Perceptual biases are thought to grow across timeevery time response units sample from perceptual units they will be sampling from a biased representation, therefore increasing the magnitude of biasing effects across a larger number of samples (Urai et al, 2019;Yon et al, 2019). In contrast, response biases are thought to operate regardless of current incoming evidence and to be present from the outset of a trialanalogous to setting a threshold criterion for responses (Leite & Ratcliff, 2011).…”