Human foraging behavior in a virtual environment

We have developed an experimental platform that allows a large number of human participants to interact in real time within a common virtual world. Within this environment, human participants foraged for resources distributed in two spatially separated pools. In addition to varying the relative replenishment rate for the two pools (50-50, 65-35, or 80-20), we manipulated whether the participants could see each other and the entire resource distribution or had their vision restricted to resources at their own location. Two empirical deviations from an optimal distribution of the participants were found. First, the participants were more scattered within a resource pool than the resources were themselves. Second, there was systematic underutilization of the richer pool. For example, the participants distributed themselves 73% and 27% to resource pools that had replenishment rates of 80% and 20%, respectively. In addition, there were oscillations in the harvesting rate of the pools across time, revealed by a Fourier analysis with prominent power near 50 sec per cycle. The suboptimalities and oscillations were more apparent when the locations of the participants and the food were not visible. Individual participant knowledge thus affects the efficiency with which a population of participants harvests resources.

[1]  A. J. Lotka,et al.  Elements of Physical Biology. , 1925, Nature.

[2]  W M Baum,et al.  Group choice: the ideal free distribution of human social behavior. , 2001, Journal of the experimental analysis of behavior.

[3]  Gregory J Madden,et al.  Human group choice: discrete-trial and free-operant tests of the ideal free distribution. , 2002, Journal of the experimental analysis of behavior.

[4]  R. Gray,et al.  Can ecological theory predict the distribution of foraging animals? A critical analysis of experiments on the ideal free distribution , 1993 .

[5]  F. Tonneau,et al.  The ideal free distribution in humans: An experimental test , 1999, Psychonomic bulletin & review.

[6]  William M Baum,et al.  Group foraging sensitivity to predictable and unpredictable changes in food distribution: past experience or present circumstances? , 2002, Journal of the experimental analysis of behavior.

[7]  W M Baum,et al.  On two types of deviation from the matching law: bias and undermatching. , 1974, Journal of the experimental analysis of behavior.

[8]  Alasdair I. Houston,et al.  The ideal free distribution when competitive abilities differ: an approach based on statistical mechanics , 1988, Animal Behaviour.

[9]  Anil K. Seth,et al.  Modeling Group Foraging: Individual Suboptimality, Interference, and a Kind of Matching , 2001, Adapt. Behav..

[10]  S. Fretwell,et al.  On territorial behavior and other factors influencing habitat distribution in birds , 1969 .

[11]  永福 智志 The Organization of Learning , 2005, Journal of Cognitive Neuroscience.

[12]  A. J. Lotka Elements of Physical Biology. , 1925, Nature.

[13]  J. Godin,et al.  Foraging on patchily distributed prey by a cichlid fish (Teleostei, Cichlidae): A test of the ideal free distribution theory , 1984, Animal Behaviour.

[14]  Luc-Alain Giraldeau,et al.  Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment , 1996, Behavioral Ecology and Sociobiology.

[15]  D. Harper Competitive foraging in mallards: “Ideal free’ ducks , 1982, Animal Behaviour.