Separable Forms of Reality Monitoring Supported by Anterior Prefrontal Cortex

Abstract

Reality monitoring refers to the process of discriminating between internally-and externallygenerated information. Two different tasks have often been used to assess this ability: memory for perceived vs. imagined stimuli; and memory for participant-vs. experimenter-performed operations, but it is not known whether these two reality monitoring tasks share neural substrates. The present study involved use of a within-subjects fMRI design to examine common and distinct brain mechanisms associated with the two reality monitoring conditions. The sole difference between the two lay in greater activation in medial anterior prefrontal cortex when recollecting whether the participant or the experimenter had carried out an operation during prior encoding as compared to recollecting whether an item had been perceived or imagined. This region has previously been linked with attending to mental states. Task differences were also reflected in the nature of functional connectivity relationships between medial anterior and right lateral prefrontal cortex: there was a stronger correlation in activity between the two regions during recollection of self/experimenter context. This indicates a role for medial anterior prefrontal cortex in the monitoring of retrieved information relating to internal or external aspects of context. Finally, given the importance of reality monitoring to understanding psychotic symptoms, brain activity was related to measures of proneness to psychosis and schizotypal traits. The observation of significant correlations between reduced medial anterior prefrontal signal and scores on such measures corroborates these theoretical links.

Aging and the neural correlates of source memory: over-recruitment and functional reorganization

“…Anterior PFC activation (or reduced deactivation) is frequently seen during context retrieval (e.g., Dobbins & Wagner, 2005;Simons et al, 2005aSimons et al, , 2005b; see also Mitchell & Johnson, 2009). The precise functional significance of anterior PFC for source memory is still under debate, but our results are consistent with the idea that medial anterior PFC mediates the retrieval of internally generated contextual details, such as the thoughts and associations produced during semantic encoding (e.g., Dobbins & Wagner, 2005;Simons et al, 2005aSimons et al, , 2005bSimons et al, , 2008. This hypothesis would explain why the source memory task was associated with less deactivation of anterior PFC than the item memory task, which would require retrieval of fewer details.…”

The Neural Basis of Metacognitive Ability

“…Further, compared with non-human primates, rlPFC has a sparser spatial organization that may support greater interconnectivity [100]. The contribution of rlPFC to metacognitive commentary may be to represent task uncertainty in a format suitable for communication to others, consistent with activation here being associated with evaluating self-generated information [101,102], and attention to internal representations [103]. Such a conclusion is supported by recent evidence from structural brain imaging that 'reality monitoring' and metacognitive accuracy share a common neural substrate in anterior PFC [104].…”

The Neural Basis of the Dynamic Unconscious

“…If so, it can be presumed that the neural processes regulating the emotional and behavioral responses to the stimuli-that is, the unconscious dynamic processes trigged by the stimuli-should be similar. Neuroscientific studies have in fact shown that while certain brain areas like the medial anterior (PFC) monitor whether a stimulus is internally or externally generated (Simons, Henson, Gilbert, & Fletcher, 2008), there is significant overlap between cortical areas that are activated regardless of whether a stimulus is generated internally or presented externally (Helmchen, Mohr, Erdmann, Binkofski, & Büchel, 2006;Stawarczyk, Majerus, Maquet, & D'Argembeau, 2011). For example, in the visual domain, imagery activates similar regions of visual cortex as retinal input does (Reddy, Tsuchiya, & Serre, 2010), and this has also been shown at the single-neuron level (Kreiman, Koch, & Fried, 2000).…”