Prefrontal Regions Orchestrate Suppression of Emotional Memories via a Two-Phase Process

Abstract

Whether memories can be suppressed has been a controversial issue in psychology and cognitive neuroscience for decades. We found evidence that emotional memories are suppressed via two time-differentiated neural mechanisms: (i) an initial suppression by the right inferior frontal gyrus over regions supporting sensory components of the memory representation (visual cortex, thalamus), followed by (ii) right medial frontal gyrus control over regions supporting multimodal and emotional components of the memory representation (hippocampus, amygdala), both of which are influenced by fronto-polar regions. These results indicate that memory suppression does occur and, at least in nonpsychiatric populations, is under the control of prefrontal regions.

Towards a Cognitive and Neurobiological Model of Motivated Forgetting

“…Forty-three participants from three age groups (fi fteen 8-9 year olds, fourteen 11-12 year olds, and 14 young adults) were scanned as they performed the Think/No-Think task. Aggregating across all 43 participants showed robust engagement of right DLPFC and VLPFC during retrieval suppression, and a clear reduction in hippocampal activity during Suppress trials, consistent with the foregoing imaging studies by Anderson et al ( 2004 ) and Depue et al ( 2007 ) . Moreover, activity in DLPFC was functionally related to activity in the hippocampus during retrieval suppression, indicating an interaction between these regions that helps to implement the process of retrieval suppression.…”

“…A particularly nice illustration comes from the study by Depue et al ( 2007 ) discussed earlier, in which participants showed a 9% negative control effect in their ability to recall scenes in response to faces (Fig. 7 ).…”

“…A number of studies have found negative control effects in which the trace to be suppressed was negative, including negative words (Depue et al, 2006 ;Hertel & McDaniel, 2010 ;Joormann et al, 2005 ;Joormann et al, 2009 ;LeMoult et al, 2010 ;Kim et al, 2007 ;Lambert et al, 2010. Murray, Muscatel, & Kensinger, 2011 and negative pictures ( Depue et al, 2007 ) .…”

“…Would the brain systems identifi ed in that study be engaged by non-verbal materials that are aversive in character? Depue et al ( 2007 ) studied this issue using the face-scene associations described earlier. Importantly, during the Think/No-Think task, when participants viewed a face and tried to suppress retrieval of the associated aversive image, they showed signifi cantly more activation in right dorsolateral prefrontal cortex than during the Respond condition.…”

“…Studies have used face-word pairs (Depue, Banich, & Curran, 2006 ;Hanslmayr et al, 2010 ;Hanslmayr et al, 2009 ) , word-face and word-place pairs (Detre, Natarajan, & Norman 2010 ;Huddleston & Anderson, in preparation ) , word-line-drawing pairs (Kim & Yi, 2008 ) , and face-scene pairs (Depue et al, 2006 ;Depue, Curran, & Banich, 2007 ;Depue, Banich, Burgess, Willcut, & Ruzic, 2010 ). For example, in a study by Depue et al ( 2007 ) , participants studied pairs composed of faces and complex scenes varying widely in content, and were trained on these pairs until they could recognize the scene that went with each face. During the Think/No-Think phase, participants were presented with the Faces as cues, and asked to either retrieve the associated scene or to suppress it.…”