The work on episodic simulation examines the core brain network involved in recollecting the past and imagining the future (Benoit & Schacter, 2015), with an emphasis on medial prefrontal cortex and the hippocampus (Benoit, Szpunar, & Schacter, 2014). It seeks to elucidate the mechanisms by which imagining the future can bias decisions towards more farsighted outcomes (Benoit, Gilbert, & Burgess, 2011). In recent work, we have also provided evidence that mere simulations can induce learning much in the same way as actual experiences, thus shaping our real-life attitudes and models of the world (Benoit, Paulus, & Schacter, in press). However, despite the clear adaptive value of envisaging the future, dwelling too much on the future may also have aversive consequences. I examine how, in such situations, the mechanisms involved in memory suppression get also engaged to effectively stop imagining (Benoit, Davies, & Anderson, 2016; see above).
(i) Memory suppression
The work on voluntary forgetting seeks to understand the different neurocognitive mechanisms underlying the ability to suppress unwanted memories. We have reported evidence for two opposing mechanisms that can achieve memory suppression (Benoit & Anderson, 2012): one by effectively shutting down hippocampal retrieval processes (i.e., direct suppression) and the other by guiding hippocampal retrieval towards the recollection of alternative memories that then keep the unwanted memory out of awareness (i.e., thought substitution). I examine how these mechanisms can be adaptively recruited to purge intrusive memories from consciousness (Benoit et al., 2015), and whether they may be compromised in people who suffer deficits in controlling unwanted thoughts (e.g., Kupper, Benoit, et al., 2014). In recent work, we have established that a mechanism akin to direct suppression can also be engaged to control persistent imaginings of future fears (Benoit, Davies, & Anderson, in 2016) (see also ii).
(iii) Prefrontal cortex functioning
This work focuses on the memory functions of the medial prefrontal cortex (PFC). We have provided evidence that this region codes for affective representations of our environment (e.g., of familiar people and places) that can be flexibly engaged for the simulation of possible future events (Benoit et al., 2011; 2014; in press). We currently seek to understand the interactions of this region with the medial temporal lobes, both in the service of retrieving individual episodic memories and for the formation of affective memory schemas. In addition, our research on suppression adds to our understanding of the lateral PFC by showing how its subregions influence processing in other parts of the brain, notably the hippocampus (Benoit & Anderson, 2012; Benoit et al., 2015). Further research is targeted at determining the functional organization of rostral prefrontal cortex, i.e., the most anterior part of the brain (e.g., Benoit, et al., 2010; 2012).
Key publications (in addition to those listed above):
Gilbert, S.J., Frith, C.D., Burgess, P.W. (2012). Rostral prefrontal cortex and the focus of attention in prospective memory. Cerebral Cortex
22(8), 1876-1886. pdf
Benoit, R.G., Gilbert, S.J., Volle E., Burgess, P.W. (2010). When I think about me and simulate you: Medial rostral prefrontal cortex and self-referential processes. NeuroImage 50(3), 1340-1349. pdf