Individual differences in social reward and threat expectancies linked to grey matter volumes in key regions of the social brain

Prospection (mentally simulating future events) generates emotionally charged mental images that guide social decision-making. Positive and negative social expectancies - imagining new social interactions to be rewarding vs. threatening - are core components of social approach and avoidance motivation, respectively. Stable individual differences in such positive and negative future-related cognitions may be underpinned by distinct neuroanatomical substrates. Here, we asked 100 healthy adults to vividly imagine themselves in a novel self-relevant social scenario that was ambiguous with regards to possible social acceptance or rejection. During this task we measured their expectancies for social reward (e.g. anticipated feelings of social connection) or threat (e.g. anticipated feelings of rejection). On a separate day they underwent structural MRI; voxel-based morphometry (VBM) was used to explore the relation between their social reward and threat expectancies and regional grey matter volumes (rGMV). Increased rGMV in key regions involved in prospection, subjective valuation and emotion regulation (including ventromedial prefrontal cortex), correlated with both higher social reward and lower social threat expectancies. In contrast, social threat expectancies were uniquely linked with rGMV of regions involved in social attention (posterior superior temporal sulcus) and interoception (somatosensory cortex). These findings provide novel insight into the neurobiology of future-oriented cognitive-affective processes critical to adaptive social functioning

Normal Alert Consciousness: A Central Executive Model of Hippocampal Function

The relationship between brain and consciousness has been debated since Descartes in the 1500s, new theories arising in the twentieth century with the development of modern neuroscience. All are controversial due to the lack of consensus on the definition of consciousness, what cognitive properties must be explained, and how to evaluate sentience. Most theoretical explanations bear little relationship to our inner conscious experiences. In the current monograph, the normal alert state of consciousness is defined, and components to be explained are delineated. Debunking misconceptions from previous theories and presenting new evidence, a model is proposed whereby the hippocampus plays a central role in executing and coordinating cognitive functions associated with normal alert consciousness. Key elements of the model reflect recent findings that the combined effect from the left and right hippocampus influences other regions involved in performing many or all cognitive tasks while filtering out irrelevant information. Methods are described for testing the model. Finally, implications are discussed for a variety of neurological disorders and philosophophical issues, including free will and the possibility of sentience in artificial intelligence