The effects of recent perceptual history on stream-bounce perception.

Abstract

We examine perceptual disambiguation and crossmodal interactions by considering the effect of recent perceptual history on stream-bounce perception. First, we tested the assumption that the audio-visual stream-bounce effect (visual-only trials mostly stream, whereas audio-visual trials mostly bounce) reflects some intrinsic preference for streaming that is broken by sound. Instead, we found that for naïve observers, visual-only stimuli are bistable and bias free. In intermixed trials, sound acts as a polarizing factor (rather than a bounce-inducing factor) and has as much effect on visual-only trials as it does on audio-visual trials. Second, temporal context exerts a comparative influence and exposure to audio-visual stimuli influences responses to visual-only stimuli and vice-versa. Finally, there is a serial dependence in responses and the current stimulus (unisensory or multisensory) is interpreted with a bias to recent interpretations. Recent perceptual history exerts a substantial influence on the perception of stream-bounce stimuli. This influence occurs in the unisensory case and is in line with an extensive literature on visual bistability; it extends to the multisensory case, and there are interactions between the 2 cases. Our combined findings support a role for top-down interpretational influences in the streambounce effect and stream-bounce perception more generally. Public Significance StatementAlthough sensory information is typically ambiguous, our perception is not. This study supports the idea that in dealing with ambiguity, the perceptual system analyses recent perceptual history across the sensory modalities to predict the immediate sensory future and these predictions alter what is perceived. Given the requirement on the brain to provide an informative, clear, and stable representation of a complex and ever-changing outside world, and the computational burden this involves, making heavy use of experience is efficient and adaptive.

Implicit expectation modulates multisensory perception

“…Imagined and perceived tones were associated with equivalent bouncing biases, while missed and perceived no-tones were associated with identical streaming biases, suggesting an importance of perception over the actual stimulus. Later, Zeljko and Grove ( 2021 ) examined the influence of previous trials on stream-bounce responses and found a strong serial dependence of the previous response but no effect of the previous stimulus and concluded that current perceptual interpretations depend on previous perceptual decisions and not previous stimuli.…”

“…There is some uncertainty regarding the origin of auditory induced bouncing in terms of bottom-up versus top-down processing and sensory versus cognitive processes (for a review, see Grove et al, 2016 ). While there is no definitive explanation, there is compelling evidence that cognitive inference plays a substantial role (Zeljko & Grove, 2021 ), although Maniglia et al ( 2012 ) found evidence supporting a multisensory integration account involving posterior parietal cortex. We suggest two possible explanations.…”

“…For example, Biederman et al ( 1982 ) found that object detection in a scene was impaired when the object was unlikely in that particular scene, located in an inappropriate position in the scene, or was too large or too small relative to the other objects in the scene. Additionally, prior knowledge in the form of learned associations have been shown to bias perceptual decisions regarding ambiguous stimuli (Einhäuser et al, 2017 ), priming (e.g., Bugelski & Alampay, 1961 ; Intaitė et al, 2013 ; Ouhnana & Kingdom, 2016 ), and serial dependence (e.g., Brascamp et al, 2010 ; Pearson & Brascamp, 2008 ; Zeljko & Grove, 2021 ).…”

“…Finally, Zeljko and Grove ( 2021 ) examined perceptual disambiguation and crossmodal interactions by considering the effect of recent perceptual history on stream-bounce perception. The authors compared groups of naïve stream-bounce observers first exposed to either only audio-visual or only visual-only stream-bounce stimuli, and then to mixed audio-visual and visual-only stimuli.…”

The influence of tDCS on perceived bouncing/streaming

“…This may have implications for theories addressing the origin of the bouncing-streaming illusion. Some recent findings suggest that the bouncing impression arise at a perceptual level (Meyerhoff and Scholl 2018 ; Meyerhoff and Suzuki 2018 ; for different views see Grassi and Casco 2009 , 2010 ; Grove et al 2012 ; Zeljko and Grove 2021 ). Another possibility is that the area already had reached its processing peak and thus increasing neural processing via anodal tDCS could not have an up-regulatory effect.…”