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Full-Text Articles in Psychology
Vocalizations By Isolated Piglets: A Reliable Indicator Of Piglet Need Directed Towards The Sow, Daniel M. Weary, Stephen Ross, David Fraser
Vocalizations By Isolated Piglets: A Reliable Indicator Of Piglet Need Directed Towards The Sow, Daniel M. Weary, Stephen Ross, David Fraser
Communication Skills Collection
When suckling piglets are isolated from the sow and litter-mates they vocalize a great deal. Sows also call when isolated from their piglets. In one experiment, we found that isolated piglets doubled their call rate in response to playback of sow calls, indicating that piglets are directing calls towards the sow. In a second experiment, we found that variation in the piglet isolation calls related to aspects of the piglet's condition: piglets isolated for 13 min in an enclosure kept at approximately 14°C called more, used higher frequency calls and longer calls, than litter-mates isolated in an enclosure kept at …
Development Of Piagetian Object Permanence In A Grey Parrot (Psittacus Erithacus), Irene M. Pepperberg, Mark R. Willner, Lauren B. Gravitz
Development Of Piagetian Object Permanence In A Grey Parrot (Psittacus Erithacus), Irene M. Pepperberg, Mark R. Willner, Lauren B. Gravitz
Sentience Collection
The authors evaluated the ontogenetic performance of a grey parrot (Psittacus erithacus) on object permanence tasks designed for human infants. Testing began when the bird was 8 weeks old, prior to fledging and weaning. Because adult grey parrots understand complex invisible displacements (I. M. Pepperberg & F. A. Kozak, 1986), the authors continued weekly testing until the current subject completed all of I. C. Uzgiris and J. Hunt's (1975) Scale 1 tasks. Stage 6 object permanence with respect to these tasks emerged at 22 weeks, after the bird had fledged but before it was completely weaned. Although the parrot progressed …
Language-Naive Chimpanzees (Pan Troglodytes) Judge Relations Between Relations In A Conceptual Matching-To-Sample Task, Roger K.R. Thompson, David L. Oden, Sarah T. Boysen
Language-Naive Chimpanzees (Pan Troglodytes) Judge Relations Between Relations In A Conceptual Matching-To-Sample Task, Roger K.R. Thompson, David L. Oden, Sarah T. Boysen
Sentience Collection
Three chimpanzees with a history of conditional and numeric token training spontaneously matched relations between relations under conditions of nondifferential reinforcement. Heretofore, this conceptual ability was demonstrated only in language-trained chimpanzees. The performance levels of the language-naive animals in this study, however, were equivalent to those of a 4th animal—Sarah—whose history included language training and analogical problem solving. There was no evidence that associative factors mediated successful performance in any of the animals. Prior claims of a profound disparity between language-trained and language-naive chimpanzees apparently can be attributed to prior experience with arbitrary tokens consistently associated with abstract relations and …