Serial dependence in numerosity perception

Abstract

Our conscious experience of the external world is remarkably stable and seamless, despite the intrinsically discontinuous and noisy nature of sensory information. Serial dependencies in visual perception—reflecting attractive biases making a current stimulus to appear more similar to previous ones—have been recently hypothesized to be involved in perceptual continuity. However, while these effects have been observed across a variety of visual features and at the neural level, several aspects of serial dependence and how it generalizes across visual dimensions is still unknown. Here we explore the behavioral signature of serial dependence in numerosity perception by assessing how the perceived numerosity of dot-array stimuli is biased by a task-irrelevant “inducer” stimulus presented before task-relevant stimuli. First, although prior work suggests that numerosity perception starts in the subcortex, the current study rules out a possible involvement of subcortical processing in serial dependence, confirming that the effect likely starts in the visual cortex. Second, we show that the effect is coarsely spatially localized to the position of the inducer stimulus. Third, we demonstrate that the effect is present even with a stimulus presentation procedure minimizing the involvement of post-perceptual processes, but only when participants actively pay attention to the inducer stimulus. Overall, these results provide a comprehensive characterization of serial dependencies in numerosity perception, demonstrating that attractive biases occur by means of spatially localized attentional modulations of early sensory activity.

The role of feature-based attention in visual serial dependence

“…Moreover, it has been previously shown that feature-based attention itself can be serially dependent (White, Rolfs, & Carrasco, 2013), and thus the orientation reproduction of the test stimulus on each trial might have facilitated the allocation of attentional resources to orientation information of the next trial's inducer even when that orientation was task irrelevant. In a similar vein, previous findings of serial dependence to task-irrelevant stimulus features could be explained by residual attention to the feature dimension for which serial dependence was assessed (Fornaciai & Park, 2018a, 2018b.…”

“…order to exert a serial-dependence bias in subsequent perceptual decisions. While serial dependence has been shown to depend on spatial attention toward the previous stimulus location , it has also been reported to occur when previous stimuli were task irrelevant (Fornaciai & Park, 2018a, 2018b), suggesting that attention to a particular stimulus feature is not necessary for serial dependence to occur. In a similar vein, serial dependence is often thought to arise on the level of objects (Liberman et al, 2014;Liberman et al, 2018), suggesting that attention to a particular stimulus feature might not be necessary as long as the object is spatially attended.…”

Laws of concatenated perception: Vision goes for novelty, decisions for perseverance

“…Although this is an intriguing possibility that deserves future investigation, the similarity between the repulsive bias in Experiment 3 and the one in Experiment 5 (in which adaptation was facilitated in the absence of backward masking and with short interstimulus intervals) justifies our interpretation of repulsive biases as emerging from low-level adaptation effects. A further intriguing alternative might be that positive and negative history biases result from attentional selection [26,94], which acts as a gating mechanism that enables or blocks the persistence of perceptual traces based on the relevance of sensory events [95]. This seems quite plausible if one assumes that negative biases are the consequence of inhibitory (e.g., below baseline) modulations of early sensory activity induced by the top-down attentional suppression of irrelevant stimuli.…”

Context information supports serial dependence of multiple visual objects across memory episodes

“…This bias was enhanced by spatial and temporal item proximity as well as by attentional selection and was termed 'serial dependence'. It has since been observed for other modalities, including facial identity and expression 4,5 , spatial positions 6,7 , numerosity [8][9][10] or ensemble representations 11 . As serial dependence reduces differences in the appearance of similar consecutive objects, it has been interpreted as promoting perceptual stability and continuity of a visual object over time 3 .…”