Episodic memory retrieval affects the onset and dynamics of evidence accumulation during value-based decisions
AO_SCPLOWBSTRACTC_SCPLOWIn neuroeconomics, there is much interest in understanding simple value-based choices where agents choose between visually presented goods, comparable to a shopping scenario in a supermarket. However, many everyday decisions are made in the physical absence of the considered goods, requiring agents to recall information about the goods from memory. Here, we asked whether and how this reliance on an internal memory representation affects the temporal dynamics of decision making on a cognitive and neural level. Participants performed a remember-and-decide task, in which they made simple purchasing decisions between money offers and snack items while undergoing EEG. Snack identity was presented either visually (value trials) or had to be recalled from memory (memory trials). Behavioral data indicated comparable choice consistency across both trial types, but considerably longer response times (RT) in memory trials. Drift-diffusion modeling suggested that this RT difference was due to longer non-decision time of decision processes as well as altered evidence accumulation dynamics (lower accumulation rate and higher decision threshold). The non-decision time effect was supported by a delayed onset of the lateralized readiness potential. These results show that both, decision and non-decision processes are prolonged when participants need to resort to internal memory representations during value-based decisions.