Medial prefrontal cortex dissociation between self and others in a referential task:
An fMRI study based on word traits.
Journal of Physiology,107 (2013) 517-525
A number of recent neuroimaging studies using self referential tasks have investigated
whether self referential processing depends on a unique neural basis that operates
specifically in the medial prefrontal cortex. However, these studies have provided
contradictory results despite the use of similar methodologies. We hypothesized that
these discrepancies are partially related to the task-difficulty that presents dissociations
reaction times in the self- and other-referential tasks. We therefore measured brain
activity during self and other referential tasks to determine if such activity can be
dissociated according to the reaction times (fast versus slow) for the trait words.
Activation differed across self and other only in the slow word condition. The self
referential condition with slow reaction time produced greater activation
in the ventromedial prefrontal cortex, whereas the other referential condition with slow
reaction time produced activation of the middle temporal gyrus. Results suggested
that the task-difficulty might affect whether or not brain activities within MPFC would
be dissociated between self- and other-referential processing.