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Full-Text Articles in Life Sciences
Quantity-Based Interference And Symbolic Representations In Chimpanzees (Pan Troglodytes), S. T. Boysen, G. G. Berntson, M. B. Hannan, J. T. Cacioppo
Quantity-Based Interference And Symbolic Representations In Chimpanzees (Pan Troglodytes), S. T. Boysen, G. G. Berntson, M. B. Hannan, J. T. Cacioppo
Sentience Collection
Five chimpanzees with training in counting and numerical skills selected between 2 arrays of different amounts of candy or 2 Arabic numerals. A reversed reinforcement contingency was in effect, in which the selected array was removed and the subject received the nonselected candies (or the number of candies represented by the nonselected Arabic numeral). Animals were unable to maximize reward by selecting the smaller array when candies were used as array elements. When Arabic numerals were substituted for the candy arrays, all animals showed an immediate shift to a more optimal response strategy of selecting the smaller numeral, thereby receiving …
Mechanisms Of American English Vowel Production In A Grey Parrot (Psittacus Erithacus), Denice K. Warren, Dianne K. Patterson, Irene M. Pepperberg
Mechanisms Of American English Vowel Production In A Grey Parrot (Psittacus Erithacus), Denice K. Warren, Dianne K. Patterson, Irene M. Pepperberg
Sentience Collection
Parrots are known for their capacity to reproduce the sounds of human speech, but few studies have investigated their mechanisms for producing such vocalizations. Using three methods of noninvasive video imaging (Super VHS video, infrared, X-ray radiography), we examined correlations between several elements of a Grey Parrot's (Psittacus erithacus) vocal-tract configuration and the bird's production of two vowels, /i/ ("eat") and /a/ ("rock"). This parrot uses mechanisms that both resemble and differ from those used by: (a) humans to produce English speech; and (b) some avian species to produce conspecific vocalizations. This Grey Parrot, for example, uses its vocal apparatus …