Temporal dynamics of a perceptual decision

Abstract

Previous research suggests that cognitive factors acting in a top-down manner influence the perceptual interpretation of ambiguous stimuli. To examine the temporal unfolding of these influences as a perceptual decision evolves, we have implemented a modified version of the stream-bounce display. Our novel approach allows us to track responses to stream-bounce stimuli dynamically over the entire course of the motion sequence rather than collecting a subjective report after the fact. Using a trackpad, we had participants control a cursor to track a stream-bounce target actively from start to end and measured tracking speed throughout as the dependent variable. Our paradigm replicated the typical effect of visual-only displays being associated with a streaming bias and audiovisual displays with a bouncing bias. Our main finding is a significant behavioral change preceding a perceptual decision that then predicts that decision. Specifically, for trials in which the sound was presented, tracking speeds were significantly slower starting 500 ms before the point of coincidence and presentation of the sound for bounce compared to stream responses. We suggest that behavioral response may reflect a cognitive expectation of a perceptual outcome that then biases action and the interpretation of sensory input to favor that forthcoming percept in a manner consistent with both the predictivecoding and common-coding theoretical frameworks. Our approach provides a novel behavioral corroboration of recent imaging studies that are suggestive of early brain activity in perception and action. DataOnly data from test blocks (both objective and subjective motion) were recorded for analysis.

Introduction to special issue on “Prediction in Perception and Action”

“…Fooken and Spering (2019) used a go/no-go manual interception paradigm to show that predictive eye and hand movements jointly signal the upcoming decision about a future target. Similar predictive behavioral responses are shown in a manual tracking task, where different cursor speeds were related to different perceptual decisions (Zeljko et al, 2019). Mann et al (in press) used a virtual tennis environment to show how a combination of tracking and predictive eye and head movements helps keep gaze close to the ball despite the ball bouncing as it approaches.…”

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

“…All participants reported normal hearing and normal or corrected to normal vision, all were naïve as to the purpose of the experiment, and all reported being unfamiliar with the stream-bounce stimulus. We have selected a sample size of 25 participants per experimental group throughout this study based on a conservative approach to previous findings that stream-bounce effects are typically large ( d > .8), but serial dependency effects and temporal context effects are typically medium (e.g., Zeljko et al, 2019, found a medium effect size of d = .56 for serial dependency in a modified stream-bounce design; Parise & Ernst, 2017, found a medium effect size of φ ∼ .3 for serial dependence of response in a stream-bounce task; and Intaitė et al, 2013, found a medium effect size of d ∼ .5 for temporal context effects on Necker cube perception). We conducted a sensitivity analysis using G*Power to validate this assumption and found that two-tailed dependent means t -tests with 25 participants and an alpha of .05 could detect a medium effect size of .59 with 80% power (Faul et al, 2007).…”

Implicit expectation modulates multisensory perception

“…Sensory input provides the brain with information that reflects the current state of the world, and prior knowledge, gained through experience, provides the brain with information about how the world works (e.g., Gekas et al, 2015 ; Gilbert & Sigman, 2007 ; Kersten et al, 2004 ; Kornmeier et al, 2009 ; Maloney et al, 2005 ; Summerfield & Egner, 2009 ; Wang et al, 2013 ). While the sensory input reflects the state of the world, it always underspecifies it; sensory information is varyingly noisy, incomplete, and weak, and so in general, it is ambiguous (Parise & Ernst, 2018 ; Urgen & Boyaci, 2021 ; Zeljko et al, 2019 ). However, perceptual decisions are reached without the impression of ambiguity as the incoming sensory information is interpreted within a framework of prior knowledge (e.g., Ernst & Bülthoff, 2004 ; Gilbert & Sigman, 2007 ).…”

“…Next, Zeljko et al ( 2019 ) implemented a modified version of the stream-bounce display that tracked responses to stream-bounce stimuli dynamically over the entire course of the motion sequence rather than collecting a subjective report after the fact. Participants used a trackpad to control a cursor to track a stream-bounce target actively from the beginning to the end of its trajectory.…”