Hysteresis as an Implicit Prior in Tactile Spatial Decision Making

Abstract

Perceptual decisions not only depend on the incoming information from sensory systems but constitute a combination of current sensory evidence and internally accumulated information from past encounters. Although recent evidence emphasizes the fundamental role of prior knowledge for perceptual decision making, only few studies have quantified the relevance of such priors on perceptual decisions and examined their interplay with other decision-relevant factors, such as the stimulus properties. In the present study we asked whether hysteresis, describing the stability of a percept despite a change in stimulus property and known to occur at perceptual thresholds, also acts as a form of an implicit prior in tactile spatial decision making, supporting the stability of a decision across successively presented random stimuli (i.e., decision hysteresis). We applied a variant of the classical 2-point discrimination task and found that hysteresis influenced perceptual decision making: Participants were more likely to decide ‘same’ rather than ‘different’ on successively presented pin distances. In a direct comparison between the influence of applied pin distances (explicit stimulus property) and hysteresis, we found that on average, stimulus property explained significantly more variance of participants’ decisions than hysteresis. However, when focusing on pin distances at threshold, we found a trend for hysteresis to explain more variance. Furthermore, the less variance was explained by the pin distance on a given decision, the more variance was explained by hysteresis, and vice versa. Our findings suggest that hysteresis acts as an implicit prior in tactile spatial decision making that becomes increasingly important when explicit stimulus properties provide decreasing evidence.

Imperceptible Somatosensory Single Pulse and Pulse Train Stimulation Oppositely Modulate Mu Rhythm Activity and Perceptual Performance

“…However, the absence of a similar spectral alteration in the present EEG data ( Fig. 3A ) as well as previous findings concerning the impact of past trial history for behavioral data ( Thiel et al. 2014 ) enforced the assumption that processing in cS1 associated with the preceding trial (i.e., subthreshold single pulse or pulse train stimulation) might still interfere with the cortical response to the very succeeding stimulation event.…”

State-dependencies of learning across brain scales

“…There are peripheral, specific adaptations and more general, strategic ones. There are mechanisms driven by feedback and reward (Pleger et al, 2008 , 2009 ) and those that operate on the statistical structure of the stimuli (Preuschhof et al, 2010 ; Karim et al, 2012 ; Thiel et al, 2014 ). It has been shown that tactile PL is associated with selective changes in primary somatosensory cortex (S1; Recanzone et al, 1992 ).…”

How previous experience shapes perception in different sensory modalities

“…TCEs also occur in senses other than vision (Riskey et al, 1979 ; Hulshoff Pol et al, 1998 ; Carter et al, 2008 ; Thiel et al, 2014 ). In audition, frequency glides cause similar aftereffects as those observed for visual motion, aftereffects, whereby a test stimulus—an illusory frequency modulation in a constant-frequency stimulus—is perceived as having the opposite direction as a context stimulus with periodic frequency modulation (Shu et al, 1993 ).…”