Learned valuation during forage decision-making in cuttlefish

Abstract

Decision-making, when humans and other animals choose between two options, is not always based on the absolute values of the options but can also depend on their relative values. The present study examines whether decision-making by cuttlefish is dependent on relative values learned from previous experience. Cuttlefish preferred a larger quantity when making a choice between one or two shrimps (1 versus 2) during a two-alternative forced choice. However, after cuttlefish were primed under conditions where they were given a small reward for choosing one shrimp in a no shrimp versus one shrimp test (0 versus 1) six times in a row, they chose one shrimp significantly more frequently in the 1 versus 2 test. This reversed preference for a smaller quantity was not due to satiation at the time of decision-making, as cuttlefish fed a small shrimp six times without any choice test prior to the experiment still preferred two shrimps significantly more often in a subsequent 1 versus 2 test. This suggests that the preference of one shrimp in the quantity comparison test occurs via a process of learned valuation. Foraging preference in cuttlefish thus depends on the relative value of previous prey choices.

The effect of unexpected rewards on decision making in cuttlefish

“…In cuttlefish, we have shown that when animals make a decision between one large shrimp and two small shrimps, this depends on their appetite state; that is, they prefer a single larger shrimp when they are starving, but two smaller shrimps when they are satiated 43 . In a separate study, we have also shown that foraging decision-making by cuttlefish is dependent on the relative values learned from previous experience 44 . Cuttlefish typically preferred the larger quantity in the one vs. two shrimp test.…”

“…This suggests that cuttlefish are making foraging decisions based on a state-dependent valuation 43 . Yet in another study, it has also been shown that forage decision making by cuttlefish is dependent on relative values learned during previous experiences 44 . In the present study, we demonstrate that the unexpected reward was able to affect risk assessment by cuttlefish and this consequently changes their foraging strategy.…”

Cuttlefish exert self-control in a delay of gratification task

“…In cuttlefish, the capacity to delay gratification might have evolved in response to different ecological pressures, such as the need to optimize foraging behaviour [47]. In the wild, cuttlefish have long rest periods where they remain stationary and camouflaged for the majority of the time [71].…”

“…predators learning to stalk prey) [78]. Furthermore, diverse taxa such as great tits (Parus major) [79], bluegill sunfish (Lepomis macrochirus) [80], shore crabs (Carcinus maenas) [81] and pharaoh cuttlefish (Sepia pharaonis) [47], can learn to reject low-value prey when high-value prey are abundant. Such patterns have been argued to reflect associative learning because theoretically behavioural patterns of self-control can develop through conditioned reinforcement learning [82].…”

“…Indeed, several studies have demonstrated that cuttlefish are able to optimize their foraging behaviour through learned valuation (i.e. relative values of different prey items) [47] and by using sophisticated memory and future-oriented feeding strategies. For example, cuttlefish can remember what, where and when components of previous foraging encounters [48] and can quickly adjust their foraging behaviour in response to changing prey conditions by learning and remembering patterns of food availability [49,50].…”