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Full-Text Articles in Life Sciences
Mirror Use By African Grey Parrots (Psittacus Erithacus), Irene M. Pepperberg, Sean E. Garcia, Eric C. Jackson, Sharon Marconi
Mirror Use By African Grey Parrots (Psittacus Erithacus), Irene M. Pepperberg, Sean E. Garcia, Eric C. Jackson, Sharon Marconi
Sentience Collection
No abstract provided.
Indicating Acts During Counting By A Chimpanzee (Pan Troglodytes), Sarah T. Boysen, Gary G. Berntson, Traci A. Shreyer, Michelle B. Hannan
Indicating Acts During Counting By A Chimpanzee (Pan Troglodytes), Sarah T. Boysen, Gary G. Berntson, Traci A. Shreyer, Michelle B. Hannan
Sentience Collection
A chimpanzee (Pan troglodytes) experienced in counting arrays of 0-7 items and trained for comprehension of number symbols, spontaneously displayed a variety of indicating acts (e.g., pointing, touching, and rearranging items) during counting. Twenty-five sessions were videotaped, and all trials were evaluated for the relations among number of items presented, number of indicating acts displayed, and the Arabic number selected to represent the array. Significant correlations included the relations between number of items and the cardinal number selected by the animal, between the number of items and indicating acts displayed by the chimpanzee, and between the number of indicating acts …
Responses To Quantity: Perceptual Versus Cognitive Mechanisms In Chimpanzees (Pan Troglodytes), Sarah T. Boysen, Gary G. Berntson
Responses To Quantity: Perceptual Versus Cognitive Mechanisms In Chimpanzees (Pan Troglodytes), Sarah T. Boysen, Gary G. Berntson
Sentience Collection
Two chimpanzees were trained to select among 2 different amounts of candy (1-6 items). The task was designed so that selection of either array by the active (selector) chimpanzee resulted in that array being given to the passive (observer) animal, with the remaining (nonselected) array going to the selector. Neither animal was able to select consistently the smaller array, which would reap the larger reward. Rather, both animals preferentially selected the larger array, thereby receiving the smaller number of reinforcers. When Arabic numerals were substituted for the food arrays, however, the selector animal evidenced more optimal performance, immediately selecting the …
Comprehension Of Cause-Effect Relations In A Tool-Using Task By Chimpanzees (Pan Troglodytes), Luca Limongelli, Sarah T. Boysen, Elisabetta Visalberghi
Comprehension Of Cause-Effect Relations In A Tool-Using Task By Chimpanzees (Pan Troglodytes), Luca Limongelli, Sarah T. Boysen, Elisabetta Visalberghi
Sentience Collection
Five chimpanzees (Pan troglodytes) were tested to assess their understanding of causality in a tool task. The task consisted of a transparent tube with a trap-hole drilled in its middle. A reward was randomly placed on either side of the hole. Depending on which side the chimpanzee inserted the stick into, the candy was either pushed out of the tube or into the trap. In Experiment 1, the success rate of 2 chimpanzees rose highly above chance, but that of the other subjects did not. Results show that the 2 successful chimpanzees selected the correct side for insertion beforehand. Experiment …