Human consciousness and its relationship to social neuroscience: A novel hypothesis

Abstract

A common modern view of consciousness is that it is an emergent property of the brain, perhaps caused by neuronal complexity, and perhaps with no adaptive value. Exactly what emerges, how it emerges, and from what specific neuronal process, is in debate. One possible explanation of consciousness, proposed here, is that it is a construct of the social perceptual machinery. Humans have specialized neuronal machinery that allows us to be socially intelligent. The primary role for this machinery is to construct models of other people's minds thereby gaining some ability to predict the behavior of other individuals. In the present hypothesis, awareness is a perceptual reconstruction of attentional state; and the machinery that computes information about other people's awareness is the same machinery that computes information about our own awareness. The present article brings together a variety of lines of evidence including experiments on the neural basis of social perception, on hemispatial neglect, on the out-of-body experience, on mirror neurons, and on the mechanisms of decision-making, to explore the possibility that awareness is a construct of the social machinery in the brain.

Figure 1

Awareness as a social perceptual model of attention. Bill has his visual attention on the cup. Abel, observing Bill, constructs a model of Bill’s mental state using specialized neuronal machinery for social perception. Part of that model is the proposition that Bill is aware of the cup. In this formulation, awareness is a perceptual property that is constructed to represent the attentional state of a brain. We perceive awareness in other people. We can use the same neuronal machinery of social perception to perceive awareness in ourselves.

Figure 2

The perceptual illusion that somebody behind you is staring at you.

Figure 3

A proposed scheme that integrates simulation theory with the theory of dedicated cortical areas for social cognition. The box labeled “TPJ, STS” represents a cluster of cortical areas that contributes to building perceptual models of minds, including a self-model and models of other minds. The box labeled “MPFC” represents a prefrontal area that contributes to decisions in the social domain. The box labeled “Mirror-Neuron Systems” represents brain-wide networks that simulate and thereby refine the models of minds generated in TPJ and STS.

Figure 4

A traditional view in which consciousness emerges from the information processed in the brain. Consideration of Arrow A, how the brain creates consciousness, leads to much controversy and little insight. Consideration of Arrow B, how consciousness affects the brain, leads to the inference that consciousness must be information, because only information can act as grist for decision machinery, and we can decide that we have consciousness.