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Volume 55 (2005)
- Issue 2 Pages 49-
- Issue 1 Pages 1-
Predecessor
Volume 55, Issue 2
December
Displaying 1-4 of 4 articles from this issue
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Original Article
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IKUMA ADACHI, KAZUO FUJITAArticle type: Others
Subject area: Others
2005 Volume 55 Issue 2 Pages 49-57
Published: 2005
Released on J-STAGE: April 14, 2006
JOURNAL FREE ACCESSWe trained pigeons to discriminate photographs of human faces from those of other body parts, using a yes/no procedure. The birds were trained on the discrimination until they showed good transfer to novel stimuli. They were then tested on all-reinforced probe trials with a variety of modified “face” stimuli. The test stimuli lacked some or all of the inner features (eyes, nose, and mouth) in Experiment 1, or had some other feature of faces (color, hair, contour, and orientation) modified in Experiment 2. We found that the pigeons chose the key corresponding to “face” significantly less often for the test stimuli lacking color or hair than for intact faces. The results suggested that it was color and hair that controlled the birds' response. The weight each bird placed on any given feature for solving the task varied among subjects. In Experiment 3, the test stimuli lacked both color and hair. All birds chose the key corresponding to “non-face” in trials with the test stimuli. These results suggest that the pigeons used the two features to discriminate “face” and “non-face” stimuli in an additive way.View full abstractDownload PDF (1593K)
Short Report
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ATSUKO KON-NO, KIYOSHI ASAHINA, CHIHIRO YUMIOKA, HIROSHI KOBAYASHI, TS ...2005 Volume 55 Issue 2 Pages 59-64
Published: 2005
Released on J-STAGE: April 14, 2006
JOURNAL FREE ACCESSDolphins live in water and their vision plays an important role in their lives. However, there is only limited information available on the visual ability of dolphins. We examined achromatic color perception in a female bottlenose dolphin (Tursiops truncatus) using a conditional position discrimination procedure. The dolphin was first trained to choose one of the two pouched cardboards placed left or right corresponding to the sample painted either black or white. Then the subject was tested with achromatic color (gray) samples of varying brightness. The proportion of the dolphin's choice of the two locations gradually shifted according to the brightness of the sample, suggesting that the bottlenose dolphin has achromatic color perception similar to that of the human.View full abstractDownload PDF (1046K) -
RYOUSEI UENO, TOHRU TANIUCHI2005 Volume 55 Issue 2 Pages 65-69
Published: 2005
Released on J-STAGE: April 14, 2006
JOURNAL FREE ACCESSThe present study examined within-session decreases in lever pressing responses in domestic pigs bred under the ordinary feeding scheme of the livestock industry. Two castrated male pigs were trained to obtain 3.4-g food pellets by lever pressing responses. Under the continuous reinforcement schedule in 90-min sessions, pigs' response rates were completely steady for the first 30 min (about 500 pellets) and then gradually decreased. The decrease of response rates was equally well described as a linear function of cumulative food intake and that of passed time.View full abstractDownload PDF (452K) -
NARITOSHI IIDA, HIROSHI KIMURA2005 Volume 55 Issue 2 Pages 71-75
Published: 2005
Released on J-STAGE: April 14, 2006
JOURNAL FREE ACCESSThe effects of reinforcement and punishment on response suppression under variable-interval reinforcement and variable-ratio punishment schedules were investigated. At baseline, lever pressing in rats was maintained by a variable-interval food reinforcement schedule. In the punishment condition, responding was punished by a grid shock under a variable-ratio schedule in which three rats experienced four or five punishment rates and a fixed reinforcement rate. Results indicated that there was a negative linear correlation between the variable-ratio punishment rate and the response rate. Results of three rats that experienced five or six reinforcement rates with a fixed punishment rate indicated that punishment suppressed responding at all reinforcement rates. These findings suggest that the punishment rate was strongly related to response suppression under both variable-interval reinforcement and variable-ratio punishment schedules.View full abstractDownload PDF (426K)
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