PubMed HealthSearch

Biomedical subjects

J A Hogan

Publications and source records attributed to J A Hogan.

4 recordsLinked to original sources

Ontogeny of chick responses to maternal food calls in the Burmese red junglefowl (Gallus gallus spadiceus).

Burmese red junglefowl (Gallus gallus spadiceus) chicks were reinforced at 5 days old with a mealworm at the end of a runaway in the presence of a maternal food call. Two food calls were used, one made to a highly preferred food item (a mealworm) and one made to a less preferred food item (chick crumbs). Chicks initially approached the food call made to the mealworm faster regardless of reinforcement contingencies, but by the 3rd day of training chicks responded faster to the call that was reinforced. These results indicate that functional experience can modify preexisting response tendencies to food-calling stimuli. We discuss the implications of these results for the interpretation of published accounts that chickens use food calls deceptively.

Aging

Learning to find the opponent: an ethological analysis of the behavior of paradise fish (Macropodus opercularis) in intra- and interspecific encounters.

In Experiment 1, 15 behavior patterns of male paradise fish (Macropodus opercularis; n = 72) toward a male conspecific, a male of another species, or no stimulus were recorded, both in home and novel situations. In Experiment 2, the same behaviors were recorded in a runway, and the same stimuli were used as reinforcers in the goal box (n = 18). A typical learning curve was seen when the subject found a male paradise fish in the goal box, learning was followed by apparent extinction when another species was found in the goal box, and few signs of learning were seen when the goal box was empty. Performance of the fish in both experiments can be accounted for by a strong aggressive motivation, a less strong but clear general curiosity, and habituation to the experimental procedure. In contrast to recent assertions in the literature, we conclude that aggressive behavior clearly can serve as a reinforcer in an instrumental learning situation.

Aggression

"Supernormality" in a learning situation.

Four pigeons were trained to peck at a 37-spot stimulus for food. While this training continued, two of the pigeons received extinction training to a 21-spot stimulus and the other two received extinction training to a plain white stimulus. In a subsequent generalization test of stimuli which varied in number of spots, pigeons extinguished on the 21-spot stimulus responded most to the 52- and 69-spot stimuli. This "peak shift" in responding is functionally similar to "supernormality" seen in the egg-retrieval responses of gulls. Possible causes of these two phenomena are discussed and compared.

Animals