Subjective costs drive overly patient foraging strategies in rats on an intertemporal foraging task

Abstract

Laboratory studies of decision making often take the form of twoalternative, forced-choice paradigms. In natural settings, however, many decision problems arise as stay/go choices. We designed a foraging task to test intertemporal decision making in rats via stay/go decisions. Subjects did not follow the rate-maximizing strategy of choosing only food items associated with short delays. Instead, rats were often willing to wait for surprisingly long periods, and consequently earned a lower rate of food intake than they might have by ignoring long-delay options. We tested whether foraging theory or delay discounting models predicted the behavior we observed but found that these models could not account for the strategies subjects selected. Subjects' behavior was well accounted for by a model that incorporated a cost for rejecting potential food items. Interestingly, subjects' cost sensitivity was proportional to environmental richness. These findings are at odds with traditional normative accounts of decision making but are consistent with retrospective considerations having a deleterious influence on decisions (as in the "sunk-cost" effect). More broadly, these findings highlight the utility of complementing existing assays of decision making with tasks that mimic more natural decision topologies.

Emotion and relative reward processing: An investigation on instrumental successive negative contrast and ultrasonic vocalizations in the rat

“…Comparative work using animals to study reward processing has been valuable in the search for factors that mediate decision-making and choice behavior (Watanabe et al, 2001; Wikenheiser et al, 2013). Relative reward effects are pervasive in the animal kingdom (Bentosela et al, 2009; Wiegmann and Smith, 2009; Cromwell et al, 2005; Flaherty, 1996) and can be thought of as fundamental mechanisms that guide action in choice situations.…”

Characterization of exploratory activity and learning ability of healthy and “schizophrenia-like” rats in a square corridor system (AMBITUS)

“…Searching for food is also a naturally motivated behavior; thus, rodents are able to learn to retrieve food rewards located in different setups (Post et al, 2011;Vorhees & Williams, 2014). Some researchers have used a circular corridor with a few (3) side boxes (only in the outer side) with food rewards to investigate the learning capability of rodents (Wikenheiser et al, 2013;Wikenheiser & Redish, 2015;Wikenheiser & Redish, 2011). The AMBITUS system is a combination of the hole-board and the corridor tests; since similarly to the hole-board, it offers the animals the opportunity of exploring a new environment and finding several food rewards, but no open field is available.…”

“…It is well-known that in contrast to a hole-board with an open field, where the rats can show significant anxiety, rats prefer the narrow tunnels (Kimchi & Terkel, 2004). Based on this assumption, some laboratories have applied a circular corridor with or without a few side-boxes containing food rewards to evaluate the exploratory activity and/or learning abilities with a video-tracking system (Nadal, Rotllaant, Marquez, & Armario, 2005;Wikenheiser, Stephens, & Redish, 2013;Wikenheiser & Redish, 2015;Wikenheiser & Redish, 2011;Monaco, Rao, Roth, & Knierim, 2014;Newman, Climer, & Hasselmo, 2014). Unfortunately, both methods may require time-consuming data collection and/or they need long training sessions, or the commercial video-tracking systems (e.g., EthoVision XT) require special softwares which can analyze precisely the behavior of the animals.…”

Hippocampal Mechanisms for the Segmentation of Space by Goals and Boundaries

“…To dissociate these two possibilities, rats were trained to traverse around a circular track, collecting rewards by waiting a variable amount of time at each of three locations (Wikenheiser and Redish 2015). Rats had a choice to stay and wait for a reward or run to the next location, which was the optimal strategy if the wait time for reward at the more distant site was shorter (Wikenheiser et al 2013). When activity on the late phases of theta was analyzed, there was a strong correlation between the distance the rat was about to run and the places represented by the active cells.…”