The dynamics of perceptual rivalry in bistable and tristable perception

Abstract

Human observers are extremely adept at correctly interpreting the visual input that they receive despite its inherent ambiguity. There are, however, situations in which no single, valid interpretation exists and perception oscillates. Such situations offer insight into the processes underlying perception, as they reveal the conditions under which our percept can alter in the presence of an unchanging physical stimulus. Many studies have focused on perceptual switching during binocular and monocular rivalry, or when viewing ambiguous figures. The majority of these studies have focused on bistable phenomena. In this paper we report the study of a range of ambiguous stimuli that provoke tristable perception, thereby providing a more exacting test bed for current models. We find that subjects spontaneously move from periods of bistable to tristable perception and that this results in a characteristic change in the rate of perceptual switching. In contrast to reports for bistable stimuli, we find only weak evidence for consistency in the relative switch rates of individuals across our test stimuli and explain why our results are inconsistent with the theory of interhemispheric switching. We go on to describe how the results are, instead, largely consistent with models of rivalry based on mutual inhibition and adaptation.

Noise and adaptation in multistable perception: Noise drives when to switch, adaptation determines percept choice

“…For other tristable stimuli, several observations made by Naber and colleagues (2010) and Wallis and Ringelhan (2013) after pooling data over several parameters showed some commonalities with our behavioral data and could be accounted for by our model with the aforementioned roles for noise and adaptation. For instance, Naber and colleagues (2010) reported that switch-back triplets typically have longer durations than average for the intermediate percept (in our case, C) and shorter durations than average for the first percept in the triplet (in our case, T 1 ).…”

“…Although percept choice and percept switching may involve different processes (Noest, van Ee, Nijs, & van Wezel, 2007), these results suggest that a form of adaptation must be present in ambiguous visual perception. Moreover, recent results for other types of tristable visual stimuli also point in favor of an adaptation model to account for certain aspects of transitions and durations (Naber et al, 2010;Wallis & Ringelhan, 2013).…”

“…Though the dynamics of bistable rivalry have been extensively studied, attempts to generalize these models to stimuli with more than two competing percepts are scarce in the literature. However, unlike in bistable rivalry, where only temporal patterns are informative, in multistable rivalry with more than two percepts, differential transition patterns provide more insight into the plausible mechanisms that generate perceptual multistability (Burton, 2002;Suzuki & Grabowecky, 2002;Naber, Gruenhage, & Einhauser, 2010;Wallis & Ringelhan, 2013). Moreover, given that sensory information can have multiple interpretations, moving from bistability to multistability is a necessary step in achieving understanding about how the brain deals with ambiguity.…”

Time for a change: What dominance durations reveal about adaptation effects in the perception of a bi-stable reversible figure

“…Early versions of this hypothesis related perceptual reversals to neural fatigue or "satiation", and were formulated in the context of now-discredited Gestalt assumptions about the underlying physiology (Kohler & Wallach, 1944). Subsequent versions of the hypothesis have proposed that exposure to a reversible figure activates two or more mutually exclusive sets of neural structures that compete for dominance (e.g., Blake, Sobel, & Gilroy, 2003;Nawrot & Blake, 1989;Toppino & Long, 1987;Wallis & Ringelhan, 2013). Some aspect of the neural structures supporting the currently dominant percept is thought to adapt or weaken over time, until the structures underlying an alternate interpretation of the reversible stimulus gain ascendancy, producing a phenomenal reversal.…”

“…However, considerable caution should be exercised in generalizing the results and conclusions from one empirical domain to the other. Despite many similarities between the two sets of phenomena, there also are important differences (e.g., Meng & Tong, 2004;Wallis & Ringelhan, 2013). For example, many binocular rivalry effects can be traced to interocular competition, which clearly is not a factor in the perception of ambiguous stimuli (e.g., Lee & Blake, 1999;Tong, 2001;Tong & Engle, 2001).…”