Flexible coding schemes in dorsomedial prefrontal cortex underlie decision-making during delay discounting

Abstract

Determining how an agent decides between a small, immediate versus a larger, delayed reward has provided insight into the psychological and neural basis of decision-making. The tendency to excessively discount the value of delayed rewards is thought to reflect deficits in brain regions critical for impulse control such as the prefrontal cortex (PFC). This study tested the hypothesis that dorsomedial PFC (dmPFC) is critically involved in flexibly managing neural representations of strategies that limit impulsive choices. Optogenetic silencing of neurons in the rat dmPFC increased impulsive choices at an 8 sec, but not 4 sec, delay. Neural recordings from dmPFC ensembles revealed that, at the 8-sec delay, the encoding landscape transitions to reflect a deliberative-like process rather than the schema-like processes observed at the 4-sec delay. These findings show that changes in the encoding landscape reflect changes in task demands and that dmPFC is uniquely involved in decisions requiring deliberation.

Empathy incites a stable prosocial decision bias

“…Supporting this interpretation, the dmPFC has been characterized as a part of the social brain network (Adolphs, 1999;Eres, Decety, Louis, & Molenberghs, 2015;Frith & Frith, 2006;Park et al, 2017;Powers, Chavez, & Heatherton, 2015;Rilling, Sanfey, Aronson, Nystrom, & Cohen, 2004;Saxe & Kanwisher, 2003). Moreover, in the context of non-social motivated decision-making, the dmPFC has been implicated in adaptive decision processes such as encoding changes in time delay in a delay discounting task (S. M. White et al, 2023), changes in the level of effort that needs to be exerted to gain a certain reward (Soutschek, Nadporozhskaia, & Christian, 2022), or the extent of decision conflicts that arise due to changes in decision value (Mitchell et al, 2009). Such a view is further supported by recent findings that highlight the dmPFC's role in the detection and possible reduction of uncertainty when evaluating a situation (Berkay & Jenkins, 2023).…”