Background. The pathophysiology of auditory hallucinations and delusions of control has been
elucidated using functional imaging. Despite their clinical importance, there have been few similar
attempts to investigate paranoid delusions. We have examined two components of social cognition
(attentional and attributional biases) that contribute to the formation and maintenance of paranoid
delusions, using functional magnetic resonance imaging (fMRI).
Method. Normal subjects performed tasks requiring attentional and attributional judgements. We
investigated the neural response particularly associated with attention to threatening material
relevant to self and with the ‘self-serving’ attributional bias.
Results. The determination of relevance to self of verbal statements of differing emotional valence
involved left ventrolateral prefrontal cortex (left inferior frontal gyrus, BA 47), right caudate and
right cingulate gyrus (BA 24). Attention to threatening material relevant to self differentially
activated a more dorsal region of the left inferior frontal gyrus (BA 44). Internal attributions of
events, where the self was viewed as an active intentional agent, involved left precentral gyrus (BA 6)
and left middle temporal gyrus (BA 39). Attribution of events in a non ‘self-serving’ manner
required activation of the left precentral gyrus (BA 6).
Conclusions. Anomalous activity or connectivity within these defined regions may account for the
attentional or attributional biases subserving paranoid delusion formation. This provides a simple
model for paranoid delusion formation that can be tested in patients.