Channel-capacity, intelligibility and immediate memory

When subjects try to remember lists of digits played to them through pulse-modulated white noise the number of errors they make is greater than would be expected if digitrecognition errors and immediate memory errors were independent (Exp. 1).

A second experiment compared recall of digits in early list positions, when digits in subsequent list positions were presented through noise, and in clear. Digits in early positions were less well remembered when digits in later list positions had to be discriminated through noise.

In a third experiment prose passages were played to subjects who subsequently answered questions about their factual content. Judged by this technique recall of the first half of a prose passage is less accurate if the second half must be heard through noise than if the entire passage is heard through a good fidelity system. These results together are interpreted as demonstrations that increased difficulty of recognition of speech through noise may interfere with other activities, (conveniently termed “rehearsal”) which may be necessary to efficiently retain data in memory.     

A simple tachistoscope for student labs

An inexpensive tachistoscope for student labs is described that utilizes a camera shutter to control exposure duration and a potentiometer to vary light intensity. Stimuli can be drawn or typed on 3 x 5 index cards.     

Categories,subcategories, and the attenuation of proactive inhibition in free recall

In two experiments, “proactive inhibition” was observed in the free recall of a succession of 15-word lists. Recall performancc declined across lists when all lists were drawn from the same taxonomic category (e.g., occupations). But this decline did not appear when the successive lists were drawn from discrete subcategories (such as “professional” and “skilled manual” occupations). The findings clarify the conditions in which proactive inhibition effects in free recall are likely to occur. Specifically, when the set of items on any one list is more homogeneous than the set of items from all lists taken together, “proactive inhibition” will be attenuated.     

Some factors involved in the comparison of response systems: acquisition, extinction, and transfer of head-poke and lever-press Sidman avoidance

Head poking, a suggested natural escape reaction to shock for the rat, was compared to lever pressing in a Sidman avoidance study. Both responses could be emitted at any time, but only one was effective in a given session. Acquisition and extinction of the two responses were compared under both signalled and unsignalled avoidance. Then, a test for transfer was conducted in which acquisition conditions were re-instated, but the effectiveness of the responses was reversed. Three differences between responses were noted: (a) head poking was superior in reducing shock rates under signalled conditions; (b) head poking was more resistant to extinction, especially under signalled conditions; (c) under unsignalled conditions, animals were unable to learn to head poke if they had previously learned to lever press. Findings a and c were pursued in later experiments. Finding a depended on the location of the warning signal with respect to the response system. When the lever press required approach to the warning signal, the head poke was superior. But when the head poke required approach to the warning signal, the two responses were equally effective. Finding c depended on the absence of feedback for head poke during transfer. Two conclusions are offered: first, the two responses appear to obey the same laws when their topographical differences are taken into account. Second, response feedback appears to be more critical in transfer than in original acquisition.     

Aspects of language pragmatics and the social perception of lying

Two experiments were conducted in order to examine the influence of linguistic and extralinguistic variables on the attribution of lying. In the first experiment, one of two tape recordings of a target person, who responded either true or false to a list of adjectives, was evaluated by 83 subjects. The subjects' task was to attempt to discover when the target person was not telling the truth. The stimulus tapes were constructed such that the time between the adjective and the target person's response was systematically varied and the adjectives varied on the likability of a person possessing that trait. Overall, it was found that if the target person responded either too quickly or too slowly the subjects attributed his response as a lie more often than if the delay was more intermediate in duration (p<0.01). The adjective likability value in combination with the true or false response of the target person also contributed to the attribution of lying (p<0.01). In the second experiment, the adjectives were rescaled on another dimension thought to influence the attribution of lying: the degree to which the adjective is true of the general population. The results suggest that this new scale is related to the degree to which lie attributions are made.This research was supported in part by the National Institute of Child Health and Human Development under Research Grant 1 P01 HD-01762-01 and the National Institute of Mental Health under Research Grant MN 08260.     

The behavioral treatment of a “transsexual” preadolescent boy

Behavioral treatment procedures were developed to suppress feminine sex-typed behaviors and to increase masculine sex-typed behaviors in an 8-year-old boy with “childhood cross-gender identity.” The boy's clinical history paralleled the retrospective reports of adult transsexuals, including (1) feminine voice inflection and predominantly feminine content in speech, (2) verbal self-reference as “sissy” and “fag” and statements about his preference to be a girl, (3) feminine hand and arm gestures and “swishy” gait, (4) an aversion to masculine play activities, (5) a strong preference for girl playmates and taking a feminine role in play and role-playing, and (6) improvised cross-dressing. With a multiple-baseline intrasubject design across stimulus environments and across behaviors, the subject was treated sequentially in the clinic, at home, and in the school. The boy's mother was trained to administer a token economy program in the home, and the school teacher was taught to apply a response-cost procedure in the classroom. The initial treatment effects were found to be largely response specific and stimulus specific, necessitating treatment for a number of behaviors in the three major environments. Followup data 12 months after treatment termination suggest that the boy's sex-typed behaviors have become essentially normalized. This treatment holds promise for correcting pathological gender identity development in boys and for relieving the associated emotional adjustment problems.