Response latency,confidence, and ROCs in auditory signal detection

Response latencies were obtained from 10 Ss in auditory signal-detection experiments. The response latencies were inversely related to certainty that a signal was (or was not) presented. The S’s decision criterion was found to have an influence on response latency, which was consistent with the hypothesis that stimuli close to the current criterion elicit longer response latencies than stimuli more distant from the criterion. Comparisons among receiver operating characteristics derived from binary decisions, from the latencies of binary decisions, and from confidence ratings show that response latencies and binary decisions together yield more information about the stimulus than does the binary decision alone. However, the increment in information gained from the measurement of response latencies is in general (though not for every S) smaller than that gained by shifting from yes-no responses to a confidence-rating procedure.     

Transfer of responses to open and closed shapes in discrimination learning by cats

Two sets of 32 cats each were matched for performance in learning to discriminate an open and a closed shape and were then trained on a transfer task. The consistent groups were rewarded for choosing the same class of shape (open or closed) in learning and transfer. The inconsistent groups were rewarded for choosing the open figure in one task and the closed figure in the second, or vice versa. After learning the transfer task, all of the Ss relearned the original discrimination task under the same conditions that prevailed in initial training. The inconsistent groups made more errors on both the transfer and retention problems; both these differences were significant at the 0.1% level of confidence. These results and those obtained on preference tests support the hypothesis that cats classify shapes as open or closed in terms of perimeter and number of sides.     

Stimulus factors in aversive controls: conditioned suppression after equal training to two stimuli

Pigeons trained to peck a key for food were periodically presented with tones ending with electrical shock until tone presentation consistently suppressed ongoing pecks. Shock was then discontinued and gradients of stimulus generalization were assessed by presenting tones with frequencies above, below, and at the frequencies of those used to develop conditioned suppression. When the training tones had frequencies at 670 and 1500 cps, resulting gradients were bi-modal with peak suppression at 670 and 1500 cps. Of the other test tones, 1000 cps produced the most suppression. When the training tones had frequencies at 450 and 2250 cps, bi-modal gradients were again obtained with peak suppression to the 450 and 2250 cps tones. Of the other test tones, 1000 cps produced the least suppression. These results support the hypothesis that generalized response tendencies summate.     

Children's judgments of body size and distortion

Body size estimates of 69 children aged 5–13 years were obtained using a TV video methodology. Tasks included an adjustment procedure where children manipulated the width of their body image on a TV, and a discrete task, where they judged the accuracy of their TV image which was presented as either normal or distorted, that is, too wide or too thin. On the continuous task, judgments were more accurate on ascending trials where children had to increase the width of the image. On the discrete task, a signal detection analysis revealed older children were better in detecting size distortion in their images and that the differences were due to differences in the biological sensory system and not due to a bias to report that they were too fat or too thin. However, there were response bias differences between genders. Females were more likely to report size distortion with increasing age while males were less likely.