Serial Dependence in Position Perception Occurs at the Time of Perception

Abstract

Abstract:Observers perceive objects in the world as stable over space and time, even though the visual experience of those objects is often discontinuous and distorted due to masking, occlusion, camouflage, noise, etc. How are we able to easily and quickly achieve stable perception in spite of this constantly changing visual input? It was previously shown that observers experience serial dependence in the perception of features and objects, an effect that extends up to 15 seconds back in time. Here, we asked whether the visual system utilizes an object's prior physical location to inform future position assignments in order to maximize location stability of an object over time. To test this, we presented subjects with small targets at random angular locations relative to central fixation in the peripheral visual field. Subjects reported the perceived location of the target on each trial by adjusting a cursor's position to match its location. Subjects made consistent errors when reporting the perceived position of the target on the current trial, mislocalizing it toward the position of the target in the preceding two trials (Experiment 1). This pull in position perception occurred even when a response was not required on the previous trial (Experiment 2). In addition, we show that serial dependence in perceived position occurs immediately after stimulus presentation, and is a fast stabilization mechanism that does not require a delay (Experiment 3). This indicates that serial dependence occurs for position representations and facilitates the stable perception of objects in space. Taken together with previous work, our results show that serial dependence occurs at many stages of visual processing, from initial position assignment to object categorization. Introduction:

Perceptual decisions are biased toward relevant prior choices

“…In this condition, location of prior stimuli was not reported, but still had to be discriminated (otherwise the task could not be accomplished). This result is in line with previous experiments that also demonstrate serial dependence in the absence of motor actions 6,43,44 . Notably, the effect for Condition #4 (Response Inhibition) was in the same direction (positive/ attraction, as opposed to a negative/ adaptation effect) and of similar magnitude as the other relevant conditions.…”

Serial Dependence in Temporal Perception Reveals the Dynamics of Constructing an Internal Reference Frame

“…However, previous studies on serial dependence showed inconsistent results when testing serial dependence in perception without motor response in visual perceptions 32,33 . It is even more difficult to predict this result under the context of the temporal perception since previous results on duration judgment implied opposite sequential effects.…”

Sensory readout accounts for adaptation

“…Thus, behavioral adaptation may arise when adaptation outweighs awareness (an ‘ under-aware’ decoder) which could arise in paradigms where inducing stimuli are task irrelevant and presented for long periods of time 19,54 . By contrast, over-aware decoders may arise in laboratory paradigms that involve attending to and holding in memory a weak stimulus 26,27 .…”

“…In contrast to the repulsive biases associated with neural adaptation, perception is sometimes attracted to recently attended items in conditions where weak stimuli are attended – a phenomenon termed “serial dependence”. As serial dependence can impact immediate perceptual reports and the relative perception of simultaneously presented items, some have suggested that it reflects modulations in early stages of sensory processing 25–27 . In line with this idea, one fMRI study demonstrated that early sensory biases match ‘attractive’ behavioral reports 28 .…”