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Open Access Publications from the University of California


The International Journal of Comparative Psychology is sponsored by the International Society for Comparative Psychology. It is a peer-reviewed open-access digital journal that publishes studies on the evolution and development of behavior in all animal species. It accepts research articles and reviews, letters and audiovisual submissions.

Volume 7, Issue 3, 1994


Assessing the Rewarding Aspects of a Stimulus Associated with Extinction Through the Observing Response Paradigm


experiments determined the role that a stimulus associated with extinction plays in the maintenance of the observing response in goldfish. In Experiment,goldfish were trained to respond on either a mixed or a mukiple schedule of reinforcement. By swimming through a light beam at the opposite end of the tank, one group of fish could produce stimuli associated with food (S+) and  extinction (S-).In a second group, fish could terminate presentations of S+ and S-. For both groups, reward was response independent. S+ appeared to maintain the observing response, whereas S played an aversive role. In Experiment 2, goldfish were trained to respond on a multiple schedule of reinforcement. Reward was response dependent. Goldfish terminated S+ at significantly lower rate than S-. The two experiments together show that S- will not support observing even under conditions where response efficiency could be improved by observing. Results are discussed in light of theories of the observing response based on secondary reinforcement, information, and energy savings.  

Affilation as an Intervening Variable: Covariation in Measures of Affiliation in a Reproductive and a Nonreporductive Group of Rhesus Macaques (Macaca mulatta)

Affiliation is often used as an intervening variable in behavioral studies of nonhuman primates. Variables used to measure affiliation should be strongly correlated if it is a valid intervening variable. Social context also should not strongly influence relationships between variables used to measure affiliation. Few studies have, however, reported either the correlations between variables used to assess affiliation or the influence of social context on relationships between the variables. Correlations between affiliative variables were therefore calculated on data from two groups of rhesus {Macaca mulatta)and influences of social context on these correlations were assessed. Affiliation was measured with 7 variables. Two methods were used to investigate the influence of social context: Analyses were made of interactions between several age/sex categories of individuals. Comparisons were made between an experimental group and a matched control group. There were higher rates of sexual behavior in the experimental group. The mature males in the experimental group were vasectomized so females did not conceive. In this group females had repeated nonpregnant estrous cycles. Males were intact in the control group. In this group the mature females conceived and were pregnant during data collection. The variables were significantly correlated across all social contexts. Affiliation may therefore be a useful intervening variable. The magnitude of the correlations between variables did vary considerably across social contexts. Sometimes the sign of the correlations between measures changed as a function of social context. Analyses of individual variables and their interrelationships may therefore be necessary for detailed understanding of the meaning of affiliative interactions in nonhuman primates.

Use of an Egocentric Frame of Reference by Gouped Fish (Aphyocharax erithrurus) in a Spatial Discrmination

Small groups of

fish of a schooling species (Aphyocharax erithrurus) were trained to turn right or left in order to avoid being temporarily swept out of the water.This was achieved by a rotating avoidance paddle approaching them with one door (right or left) open. Once a learning criterion was attained, the direction of the paddle was reversed and both doors were opened. During these inversion trials, fish chose the door which was at the same side in relation to their body, showing that egocentric clues were used when facing the problem from an opposite viewpoint. When rtical black and white stripes were present at one side of the tank, a different response appeared during the inversion trials: fish passed through the door nearest to the stripes regardless of which door was open during training. It is concluded that these fish use  egocentric references when the spatial problem is reversed by 180°, and that this response is overridden by a tendency to swim near a vertically striped background.