Why do we leak lubricant from the eyes to solicit comfort from others? Why do we bare our teeth and crinkle our faces to express nonaggression? The defensive mimic theory proposes that a broad range of human emotional expressions evolved originally as exaggerated, temporally extended mimics of the fast, defensive reflexes that normally protect the body surface. Defensive reflexes are so important to survival that they cannot be safely suppressed; yet they also broadcast information about an animal’s internal state, information that can potentially be exploited by other animals. Once others can observe and exploit an animal’s defensive reflexes, it may be advantageous to the animal to run interference by creating mimic defensive actions, thereby manipulating the behavior of others. Through this interaction over millions of years, many human emotional expressions may have evolved. Here, human social signals including smiling, laughing, and crying, are compared component-by-component to the known, well-studied features of primate defensive reflexes. It is suggested that the defensive mimic theory can adequately account for the physical form of not all, but a large range of human emotional expression.

Surprisingly little is known about how the general public understands consciousness, yet information on common intuitions is crucial to discussions and theories of consciousness. We asked 202 members of the general public, “In your own words, what is consciousness?” and analyzed the frequencies with which different perspectives on consciousness were represented. Almost all people (89%) described consciousness as fundamentally receptive – possessing, knowing, perceiving, being aware, or experiencing. In contrast, the perspective that consciousness is agentic (actively making decisions, driving output, or controlling behavior) appeared in only 33% of responses. Consciousness as a social phenomenon was represented by 24% of people. Consciousness as being awake or alert was mentioned by 19%. Consciousness as mystical, transcending the physical world, was mentioned by only 10%. Consciousness in relation to memory was mentioned by 6%. Consciousness as an inner voice or inner being – the homunculus view – was represented by 5%. Finally, only three people (1.5%) mentioned a specific, scholarly theory about consciousness, suggesting that we successfully sampled the opinions of the general public rather than capturing an academic construct. We found little difference between men and women, young and old, or US and non-US participants, except for one possible generation shift. Young, non-US participants were more likely to associate consciousness with moral decision-making. These findings show a snapshot of the public understanding of consciousness – a network of associated concepts, represented at varying strengths, such that some are more likely to emerge when people are asked an open-ended question about it.

How do we decide to act, and how do those decisions relate to conscious choice? A new study helps dissociate the neuronal mechanisms that choose, prepare, and trigger movement from our explicit reports of conscious intention.

In the attention schema theory, awareness is an impossible, physically incoherent property that is described by a packet of information in the brain. That packet of information is an internal model and its function is to provide a continuously updated account of attention. It describes attention in a manner that is accurate enough to be useful but not so accurate or detailed as to waste time or resources. In effect, subjective awareness is a caricature of attention. One advantage of this theory of awareness is that it is buildable. No part of it requires a metaphysical leap from chemistry to qualia. In this article we consider how to build a conscious machine as a way to introduce the attention schema theory.

The purpose of the attention schema theory is to explain how an information-processing device, the brain, arrives at the claim that it possesses a non-physical, subjective awareness, and assigns a high degree of certainty to that extraordinary claim. The theory does not address how the brain might actually possess a non-physical essence. It is not a theory that deals in the non-physical. It is about the computations that cause a machine to make a claim and to assign a high degree of certainty to the claim. The theory is offered as a possible starting point for building artificial consciousness. Given current technology, it should be possible to build a machine that contains a rich internal model of what consciousness is, attributes that property of consciousness to itself and to the people it interacts with, and uses that attribution to make predictions about human behavior. Such a machine would “believe” it is conscious and act like it is conscious, in the same sense that the human machine believes and acts.

The attention schema theory is a proposed explanation for the brain basis of conscious experience. The theory is mechanistic, testable, and supported by at least some preliminary experiments. In the theory, subjective awareness is an internal model of attention that serves several adaptive functions. This chapter discusses the evolution of consciousness in the context of the attention schema theory, beginning with the evolution of attentional mechanisms that emerged more than half a billion years ago and extending to human consciousness and the social attribution of conscious states to others.

The attention schema theory offers one possible account for how we claim to have consciousness. The theory begins with attention, a mechanistic method of handling data in which some signals are enhanced at the expense of other signals and are more deeply processed. In the theory, the brain does more than just use attention. It also constructs an internal model, or representation, of attention. That internal model contains incomplete, schematic information about what attention is, what the consequences of attention are, and what its own attention is doing at any moment. This “attention schema” is used to help control attention, much like the “body schema,” the brain’s internal simulation of the body, is used to help control the body. Subjective awareness – consciousness – is the caricature of attention depicted by that internal model. This article summarizes the theory and discusses its relationship to the approach to consciousness that is called “illusionism.”

Three main views of the primate motor cortex have been proposed over the 140 years of its study. These views are not necessarily incompatible. In the homunculus view, the motor cortex functions as a rough map of the body’s musculature. In the population-code view, populations of broadly tuned neurons combine to specify hand direction or some other parameter of movement. In the recently proposed action map view, common actions in the movement repertoire are emphasized in different regions of cortex. In the action map view, to fully understand the organization of the motor cortex, it is necessary to study the structure and complexity of the movement repertoire and understand how that statistical structure is mapped onto the cortical surface. This chapter discusses the action map in the primate brain and how some of the complex actions represented there may play a role in social behavior.

The organization of the motor cortex has been studied and debated for more than 130 years. Although it contains a map of the body, the map is overlapping and fractured and therefore additional principles of organization may be needed to explain the topography. Recently, a growing body of evidence suggests one such principle. The motor cortex appears to be partly organized as a map of complex, behaviorally useful actions that compose the animal’s movement repertoire. In the action-map perspective, the statistical complexity of the movement repertoire leads to the complexity of the cortical map.

Recently we proposed a theory of consciousness, the attention schema theory, based on findings in cognitive psychology and systems neuroscience. In that theory, consciousness is an internal model of attention or an ‘attention schema.’ Consciousness relates to attention the same way that the internal model of the body, the ‘body schema,’ relates to the physical body. The body schema is used to model and help control the body. The attention schema is used to model and help regulate attention, a data-handling process in the brain in which some signals are enhanced at the expense of other signals. We proposed that attention and the attention schema co-evolved over the past half billion years. Over that time span, the attention schema may have taken on additional functions such as promoting the integration of information across diverse domains and promoting social cognition. This article summarizes some of the main points of the attention schema theory, suggests how a brain with an attention schema might conclude that it has a subjective awareness, and speculates that the same basic properties can be engineered into machines.

My son and I have a pet orangutan named Kevin. He talks to us almost every day and usually asks for a banana. All right, he’s not a pet, he’s a large hairy puppet, and I make him talk using the trick of ventriloquism. But it’s pretty fun anyway. When the puppet moves his mouth, a squeaky voice seems to come out of him, not me.