Right temporoparietal junction encodes inferred visual knowledge of others.

When people make inferences about other people's minds, called theory of mind (ToM), a cortical network becomes active. The right temporoparietal junction (TPJ) is one of the most consistently responsive nodes in that network. Here we used a pictorial, reaction-time, ToM task to study brain activity in the TPJ and other cortical areas. Subjects were asked to take the perspective of a cartoon character and judge its knowledge of a visual display in front of it. The right TPJ showed evidence of encoding information about the implied visual knowledge of the cartoon head. When the subject was led to believe that the head could see a visual change take place, activity in the right TPJ significantly reflected that change. When the head could apparently not see the same visual change take place, activity in the right TPJ no longer significantly reflected that change. The subject could see the change in all cases; the critical factor that affected TPJ activity was whether the subject was led to think the cartoon character could see the change. We also found that whether the beliefs attributed to the cartoon head were true or false did not significantly affect activity in the present paradigm. These results suggest that the right TPJ may play a role in modeling the contents of the minds of others, perhaps more than it participates in evaluating the truth or falsity of that content.

The attention schema theory in a neural network agent: Controlling visuospatial attention using a descriptive model of attention.

In the attention schema theory (AST), the brain constructs a model of attention, the attention schema, to aid in the endogenous control of attention. Growing behavioral evidence appears to support the presence of a model of attention. However, a central question remains: does a controller of attention actually benefit by having access to an attention schema? We constructed an artificial deep Q-learning neural network agent that was trained to control a simple form of visuospatial attention, tracking a stimulus with an attention spotlight in order to solve a catch task. The agent was tested with and without access to an attention schema. In both conditions, the agent received sufficient information such that it should, theoretically, be able to learn the task. We found that with an attention schema present, the agent learned to control its attention spotlight and learned the catch task. Once the agent learned, if the attention schema was then disabled, the agent's performance was greatly reduced. If the attention schema was removed before learning began, the agent was impaired at learning. The results show how the presence of even a simple attention schema can provide a profound benefit to a controller of attention. We interpret these results as supporting the central argument of AST: the brain contains an attention schema because of its practical benefit in the endogenous control of attention.

Attention, awareness, and the right temporoparietal junction.

The attention schema theory posits a specific relationship between subjective awareness and attention, in which awareness is the control model that the brain uses to aid in the endogenous control of attention. In previous experiments, we developed a behavioral paradigm in human subjects to manipulate awareness and attention. The paradigm involved a visual cue that could be used to guide attention to a target stimulus. In task 1, subjects were aware of the cue, but not aware that it provided information about the target. The cue measurably drew exogenous attention to itself. In addition, implicitly, the subjects' endogenous attention mechanism used the cue to help shift attention to the target. In task 2, subjects were no longer aware of the cue. The cue still measurably drew exogenous attention to itself, yet without awareness of the cue, the subjects' endogenous control mechanism was no longer able to use the cue to control attention. Thus, the control of attention depended on awareness. Here, we tested the two tasks while scanning brain activity in human volunteers. We predicted that the right temporoparietal junction (TPJ) would be active in relation to the process in which awareness helps control attention. This prediction was confirmed. The right TPJ was active in relation to the effect of the cue on attention in task 1; it was not measurably active in task 2. The difference was significant. In our interpretation, the right TPJ is involved in an interaction in which awareness permits the control of attention.

Temporo-parietal cortex involved in modeling one's own and others' attention.

In a traditional view, in social cognition, attention is equated with gaze and people track other people's attention by tracking their gaze. Here, we used fMRI to test whether the brain represents attention in a richer manner. People read stories describing an agent (either oneself or someone else) directing attention to an object in one of two ways: either internally directed (endogenous) or externally induced (exogenous). We used multivoxel pattern analysis to examine how brain areas within the theory-of-mind network encoded attention type and agent type. Brain activity patterns in the left temporo-parietal junction (TPJ) showed significant decoding of information about endogenous versus exogenous attention. The left TPJ, left superior temporal sulcus (STS), precuneus, and medial prefrontal cortex (MPFC) significantly decoded agent type (self versus other). These findings show that the brain constructs a rich model of one's own and others' attentional state, possibly aiding theory of mind.

Attention control and the attention schema theory of consciousness.

In the attention schema theory (AST), the brain constructs a schematic, simplified model of attention. The model is associated with three cognitive processes: a model of one's own attention contributes to the endogenous control of attention, a model of the attention of others contributes to theory of mind, and the contents of these models leads to the common human claim that we contain a non-physical consciousness or awareness inside us. Because AST is a control-engineering style theory, it can make specific predictions in complex situations. Here, over six experiments, we examined interactions between attention and awareness to test predictions of AST. Participants performed a visual task in which a cue stimulus affected their attention, as measured by their reactions to a subsequent target stimulus. The task measured both exogenous attention drawn to the cue and endogenous attention directed to a target location predicted by the cue. When participants were not aware that the cue predicted the target, both exogenous and endogenous attention effects remained. In contrast, when participants were not visually aware of the cue itself, the exogenous attention effect remained and the endogenous effect was impaired. In an additional two experiments, when participants learned an implicit shift of attention, the learning generalized from trained spatial locations to adjacent, untrained locations. Each of these findings matched predictions of AST. The results support the interpretation that attention control relies partly on an internal model that is responsible for claims of awareness.

Other people's gaze encoded as implied motion in the human brain.

Keeping track of other people's gaze is an essential task in social cognition and key for successfully reading other people's intentions and beliefs (theory of mind). Recent behavioral evidence suggests that we construct an implicit model of other people's gaze, which may incorporate physically incoherent attributes such as a construct of force-carrying beams that emanate from the eyes. Here, we used functional magnetic resonance imaging and multivoxel pattern analysis to test the prediction that the brain encodes gaze as implied motion streaming from an agent toward a gazed-upon object. We found that a classifier, trained to discriminate the direction of visual motion, significantly decoded the gaze direction in static images depicting a sighted face, but not a blindfolded one, from brain activity patterns in the human motion-sensitive middle temporal complex (MT+) and temporo-parietal junction (TPJ). Our results demonstrate a link between the visual motion system and social brain mechanisms, in which the TPJ, a key node in theory of mind, works in concert with MT+ to encode gaze as implied motion. This model may be a fundamental aspect of social cognition that allows us to efficiently connect agents with the objects of their attention. It is as if the brain draws a quick visual sketch with moving arrows to help keep track of who is attending to what. This implicit, fluid-flow model of other people's gaze may help explain culturally universal myths about the mind as an energy-like, flowing essence.

Toward a standard model of consciousness: Reconciling the attention schema, global workspace, higher-order thought, and illusionist theories.

Here we examine how people's understanding of consciousness may have been shaped by an implicit theory of mind. This social cognition approach may help to make sense of an apparent divide between the physically incoherent consciousness we think we have and the complex, rich, but mechanistic consciousness we may actually have. We suggest this approach helps reconcile some of the current cognitive neuroscience theories of consciousness. We argue that a single, coherent explanation of consciousness is available and has been for some time, encompassing the views of many researchers, but is not yet recognized. It is obscured partly by terminological differences, and partly because researchers view isolated pieces of it as rival theories. It may be time to recognize that a deeper, coherent pool of ideas, a kind of standard model, is available to explain multiple layers of consciousness and how they relate to specific networks within the brain.