REINFORCEMENT OF APPROACHING CONSPECIFICS IN ZEBRAFISH (DANIO RERIO) USING A REAL-TIME 3D TRACKING SYSTEM.

Zebrafish offer a promising animal model for examining relations between biological and behavioral processes. In addition to their fully sequenced genome, general principles of behavior observed in other species appear also in zebrafish. The fish also exhibit social behavior when placed together with conspecifics. The present research investigated whether reinforcement contingencies increase the approach to conspecifics with four pairs of zebrafish. For each pair, a male and a female fish were placed in different compartments of an aquarium separated by a thin glass partition. Their movement was tracked in 3D and in real time. Food reinforcers were delivered on their approach toward each other. For two of the four pairs, the approach response was higher in the presence of the reinforcement contingency than when food was absent or presented independently of approach responses. The other two pairs initially showed an increase in the approach response upon the introduction of the reinforcement contingency but the response was not maintained. Despite unreliability in the acquisition of the approach response, improvements in the experimental setup discussed herein could provide more reliable tests of how reinforcement contingencies influence the approach response. Relations of approaching conspecifics to social behavior are discussed.

Influence of Identity versus Oddity Pretraining on Symmetric Matching to Sample

Identity and oddity matching tasks were designed for different groups of 5-yr.-old children. The presentation of tasks continued until all children had shown evidence of appropriate generalization to new stimuli (i.e., generalized identity matching or generalized oddity from sample). All children then received training on an arbitrary matching-to-sample task. Finally, tests of reflexivity and symmetry in responding were carried out in three consecutive sessions. The children in the Identity group showed reflexivity and symmetry in responses on all three tests; the children in the Oddity group showed oddity in responses on all tests, and a gradual increase in symmetry of responses across tests. These results provide evidence against special versions of multiple-exemplar and reinforcement contingency accounts of stimulus equivalence. Versions of the accounts to explain the findings are discussed.