Latent inhibition and stimulus generalization of the classically conditioned nictitating membrane response in rabbits (Oryctolagus cuniculus) following dorsal hippocampal ablation.

Rabbits received 0 to 450 exposures of a tone conditioned stimulus (CS) prior to classical defensive conditioning of the nicitating membrane response based on an infraorbital eye shock unconditioned stimulus. Tone preexposure resulted in retarded conditioning in normal rabbits. This latent inhibition effect was not present in animals with bilateral dorsal hippocampectomy produced by aspiration. Control animals with bilateral neocortical and callosal aspiration lesions demonstrated a latent inhibition effect similar to that shown by normal nonoperated animals. The failure of CS preexposure to retard conditioning in hippocampal rabbits was not due to differences in threshold of the conditioned response to the CS or to differences in response mechanisms as determined by tests of habituation and dishabituation of the unconditioned response. A subsequent experiment employed combined-cue summation tests to confirm the fact that preexposure did not endow the tone with conditioned as well as latent inhibitiory properties. Finally, tests of stimulus generalization along the auditory frequency dimension indicated flatter relative gradients for hippocampals than for nonoperated controls, with cortical controls in between. These findings were discussed in terms of Douglas' model of hippocampal function.     

Some experiments relating to the perception of complex tones

Pattern recognition models for the perception of complex tones assume that the pitch of a complex tone is derived from more primary sensations, such as the pitches of the individual partials. Thus a complex tone will only have a well-defined pitch when at least one partial in the complex is separately perceptible. Models based on time-interval measurements, on the other hand, require an interaction of the original components, so that the periodicity of the input waveform is preserved. In Experiment I the relative intensity of a “target” tone, necessary for its identification in the presence of either one or two “masking” tones, was determined, over a range of frequencies. This intensity changes abruptly at around 5 kHz, a result consistent with the idea that the pitches of pure tones are determined by temporal mechanisms for frequencies up to 5 kHz, and by place mechanisms for frequencies above this. In Experiments II and III the audibility of the partials in a multi-tone complex was measured as a function of their frequency separation and compared with the range of conditions over which a complex stimulus produced a clear pitch sensation, using the same set of subjects in each experiment. It was found that under some conditions the complex had a well-defined pitch when none of the individual partials was separately audible. This is contrary to the predictions from the pattern recognition models. The effects of masking noise in the frequency region below the complex, and the results of individual subjects, also did not conform with the predictions from these models. Such models are not ruled out, however, for low harmonic numbers, or for stimuli containing only a small number of partials.     

External validity of role play assessment of assertive behavior

Forty female subjects, equally divided into high- and low-assertive groups on the basis of self-report data, participated in an assertion-eliciting situation. Half of the subjects were advised that the situation was not real and asked to role play their responses. Half of the subjects were uninformed that the situation was staged (natural behavior condition). High-assertive and low-assertive subjects were significantly different in both their self-report and their behavioral performance. Role play and natural behavior conditions did not differ, nor was the overall multivariate test of interactions significant. The findings indicate that role play assessment was comparable to naturally occurring behavior and provide support for the continued use of role play assessment in social skills research.     

Hemispheric alpha asymmetries of words with positive, negative, and neutral arousal values preceding tasks of recall and recognition: Electrophysiological and behavioral results from stuttering males and nonstuttering males and females

Hemispheric alpha asymmetries were obtained for stuttering males and nonstuttering males and females for words of positive, negative, and neutral arousal values. Electroencephalographic data were gathered during the presentations of stimulus words and during the actual nonoral recall and recognition of the stimulus items. Stuttering males demonstrated right-hemispheric alpha suppression across stimulus words and tasks as contrasted with left-hemispheric alpha suppression for the nonstuttering males and females. Stuttering males were also shown to recall and recognize fewer words than the nonstuttering subjects across arousal categories. Subjects were also administered a modified version of A. Paivio's (1971, In B. Randhawa & W. Coffman, Eds., Visual thinking, learning, and communication, New York: Academic Press) Individual Differences Questionnaire (IDQ). Results showed our stuttering males to have obtained lower scores on the verbal and imagery questions of the IDQ as compared to the nonstuttering groups. Hemispheric alpha asymmetry results and memory performance from the stuttering males are discussed relative to nonsegmental, right-hemispheric processing strategies.     

Classroom behavior of reflective and impulsive children

Seventy-nine children, nine or eleven years old, classified as reflective or impulsive by the Matching Familiar Figures (MFF) test, were observed in public school classrooms. A total of 15 behavioral categories were selected to capture activities often labeled “reflective” or “impulsive” in the literature. Children were observed in each of three classroom settings—Individual Work, Large Group instruction, and Small Group instruction. Thirty minutes of observational data on each child revealed substantial differences in the behavior of older and younger children and across the three settings. By contrast, there was only a minor difference in the behavior of reflective and impulsive children. These results suggest that the concept of reflection-impulsivity, as operationalized by the MFF, should be limited to tasks that involve response uncertainty, and should not be used to imply differences in the typical classroom behavior of children classified as reflective or impulsive by the MFF.     

Clothing: Communication, Compliance, and Choice

This study looks at some effects of five different styles of women's clothing: Formal Skirt, Formal Pants, Casual Skirt, Casual Pants, and Jeans. There were no significant differences in compliance to a request to fill out a questionnaire made by experimenters dressed in the five clothing styles, although experimenter age and sex effects were found. Ratings of photographs of the five dress styles indicate that a model was viewed by both male and female subjects as most happy, successful, feminine, interesting, attractive, intelligent, and wanted as a friend when wearing a Formal Skirt outfit and as least so when wearing Jeans. She was also seen as more active when wearing pants as compared with a skirt. Subjects' reasons for choosing what clothing to wear did not indicate that how one will appear to others is the major factor in clothing selection. It appears that clothing does communicate something about the wearer but may influence behavior toward her primarily in the absence of other information about her status.