Theory of Consciousness

174 Over the past several years, my colleagues and I outlined a novel approach to understanding the brain basis of consciousness. That approach was eventually called the Attention Schema Theory (AST) (Graziano 2010; Graziano and Kastner 2011; Graziano 2013; Graziano 2014; Kelly at al. 2014; Webb and Graziano 2015; Webb, Kean, and Graziano 2016; Webb et al. 2016). The core concept is extremely simple. The brain not only uses the process of attention to focus its resources onto select signals, but it also constructs a description, or representation, of attention. The brain is a model builder – it builds models of items in the world that are useful to monitor and predict. Attention, being an important aspect of the self, is modeled by an attention schema. The hypothesized attention schema is similar to the body schema. The brain constructs a rough internal model or simulation of the body, useful for monitoring, predicting, and controlling movement (Graziano and Botvinick 2002; Holmes and Spence 2004; Macaluso and Maravita 2010; Wolpert et al. 1995). Just so, the brain constructs a rough model of the process of attention – what it does, what its most basic properties are, and what its consequences are. In the theory, the internal model of attention is a high-level, general description of attention. It lacks a description of the physical nuts and bolts that undergird attention, such as synapses, neurons, and competing electrochemical signals. The model incompletely and incorrectly describes the act of attending to X as, instead, an ethereal, subjective awareness of X. Because of the information in that internal model, and because the brain knows only the information available to it, people describe themselves as possessing awareness and have no way of knowing that this description is not literally accurate. Although AST may seem quite different from other theories of consciousness, it is not necessarily a rival. Instead, I suggest it is compatible with many of the common, existing theories, and can add a crucial piece that fills a logical gap. Most theories of consciousness suffer from what might be called the metaphysical gap. The typical theory offers a physical mechanism, and then makes the assertion, “and then subjective awareness happens.” The bridge between a physical mechanism and a metaphysical experience is left unexplained. In contrast, AST has no metaphysical gap, because it contains nothing metaphysical. Instead its explanation arrives at the step, “And then the machine claims that it has subjective awareness; and its internal computations consistently and incorrectly loop to the conclusion that this self-description is literally accurate.” Explaining how a machine computes information is a matter of engineering, not a matter of 13 THE ATTENTION SCHEMA THEORY OF CONSCIOUSNESS