Multistable Perception and the Role of the Frontoparietal Cortex in Perceptual Inference

Abstract

A given pattern of optical stimulation can arise from countless possible real-world sources, creating a dilemma for vision: What in the world actually gives rise to the current pattern? This dilemma was pointed out centuries ago by the astronomer and mathematician Ibn Al-Haytham and was forcefully restated 150 years ago when von Helmholtz characterized perception as unconscious inference. To buttress his contention, von Helmholtz cited multistable perception: recurring changes in perception despite unchanging sensory input. Recent neuroscientific studies have exploited multistable perception to identify brain areas uniquely activated in association with these perceptual changes, but the specific roles of those activations remain controversial. This article provides an overview of theoretical models of multistable perception, a review of recent neuroimaging and brain stimulation studies focused on mechanisms associated with these perceptual changes, and a synthesis of available evidence within the context of current notions about Bayesian inference that find their historical roots in von Helmholtz's work.

Decoding the contents of consciousness from prefrontal ensembles

“…These results suggest that feature selective units in the primate PFC reliably reflect the dynamics of internally generated changes in the content of subjective perception even without voluntary perceptual reports. While addressing an ongoing debate between GNW and IIT about the neural correlates of conscious perception in the PFC (13,25,26,32,56), we demonstrate that the contents of subjective experience can be reliably decoded from the activity of prefrontal ensembles during single instances of internally driven transitions in conscious perception.…”

“…Additionally, reduced frontal activation accompanied inconspicuous and unreportable switches in perception, when contrasted against a condition, where perceptual changes were easily discernible (29). Together, these reports could suggest that frontal activity is related to consequences of perception, thus casting doubt on its role in conscious content representations (13,25,26,32). However, the univariate fMRI analysis comparing report vs no-report conditions (27) as well as the indirect nature and limited spatial resolution of BOLD fMRI signal compared to neuronal recordings leaves open the possibility that prefrontal ensembles do reflect the content of consciousness even without report requirements.…”

Ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy

“…Perceptual bistability-the spontaneous fluctuation of perception between two interpretations of a stimulus-can occur while observing ambiguous stimulus configurations [1][2][3][4][5][6][7]. A classic example is the Necker cube [1].…”

“…These include not just abstract, laboratory stimuli, but also complex stimuli such as speech [6] and faces [3]. Third, the proposed mechanisms of multistability are also candidate mechanisms for decision making [18,[30][31][32] and perceptual inference [5,7,18]. Fourth, bistability provides a case in which perception varies while the observed stimulus remains constant, a valuable control when testing theories of attention, awareness and consciousness [33][34][35][36].…”

Pre-stimulus feedback connectivity biases the content of visual experiences

“…Recent evidence from fMRI studies has shown that rivalry between two competing percepts is resolved relatively early in the visual hierarchy (e.g. (30,31)), such as in category-sensitive inferior temporal lobe regions ((32); but see (33) and (34) for fMRI and electrophysiological evidence showing an influence of parietal and frontal cortices; and see (35) for a recent review). In particular for the Rubin's face/vase illusion, greater BOLD activity has been observed in the fusiform face area (FFA) when participants reported seeing a face rather than a vase (36).…”