Knowledge of and planning for the future is a complex skill that is considered by many to be uniquely human. We are not born with it; children develop a sense of the future at around the age of two and some planning ability by only the age of four to five. According to the Bischof-Köhler hypothesis, only humans can dissociate themselves from their current motivation and take action for future needs: other animals are incapable of anticipating future needs, and any future-oriented behaviours they exhibit are either fixed action patterns or cued by their current motivational state. The experiments described here test whether a member of the corvid family, the western scrub-jay (Aphelocoma californica), plans for the future. We show that the jays make provision for a future need, both by preferentially caching food in a place in which they have learned that they will be hungry the following morning and by differentially storing a particular food in a place in which that type of food will not be available the next morning. Previous studies have shown that, in accord with the Bischof-Köhler hypothesis, rats and pigeons may solve tasks by encoding the future but only over very short time scales. Although some primates and corvids take actions now that are based on their future consequences, these have not been shown to be selected with reference to future motivational states, or without extensive reinforcement of the anticipatory act. The results described here suggest that the jays can spontaneously plan for tomorrow without reference to their current motivational state, thereby challenging the idea that this is a uniquely human ability.

No abstract

No abstract

Gaze direction is an important social signal in both human and nonhuman primates, providing information about conspecifics' attention, interests, and intentions. Single-unit recordings in macaques have revealed neurons selective for others' specific gaze direction. A parallel functional organization in the human brain is indicated by gaze-adaptation experiments, in which systematic distortions in gaze perception following prolonged exposure to static face images reveal dynamic interactions in local cortical circuitry. However, our understanding of the influence of high-level social cognition on these processes in monkeys and humans is still rudimentary. Here we show that the attribution of a mental state to another person determines the way in which the human brain codes observed gaze direction. Specifically, we convinced observers that prerecorded video sequences of an experimenter gazing left or right were a live video link to an adjacent room. The experimenter wore mirrored goggles that observers believed were either transparent such that the person could see, or opaque such that the person could not see. The effects of adaptation were enhanced under the former condition relative to the latter, indicating that high-level sociocognitive processes shape and modulate sensory coding of observed gaze direction.

Western scrub-jays (Aphelocoma californica) did not show extinction when caching behavior was never rewarded and they had no choice of where to cache the food. However, when the jays had the choice of caching items in 2 different locations or during 2 successive episodes, and only 1 of each was always rewarded at recovery, they rapidly learned to cache in the rewarded location or episode. When the jays had learned during training trials that their caches were always moved to 1 of 2 locations they did not cache in, then on the test trial they cached in the location that had been previously rewarded. To test whether these jays avoided the location in which their caches had been pilfered or chose the rewarded location, the procedure was repeated to include a 3rd location that was never rewarded. The jays avoided the pilfered location but cached equally in the rewarded and nonrewarded locations.