Rapid acquisition of preference in concurrent chains: effects of d-amphetamine on sensitivity to reinforcement delay

The purpose of this study was to examine effects of d-amphetamine on choice controlled by reinforcement delay. Eight pigeons responded under a concurrent-chains procedure in which one terminal-link schedule was always fixed-interval 8 s, and the other terminal-link schedule changed from session to session between fixed-interval 4 s and fixed-interval 16 s according to a 31-step pseudorandom binary sequence. After sufficient exposure to these contingencies (at least once through the pseudorandom binary sequence), the pigeons acquired a preference for the shorter reinforcement delay within each session. Estimates of the sensitivity to reinforcement immediacy were similar to those obtained in previous studies. For all pigeons, at least one dose of d-amphetamine attenuated preference and, hence, decreased estimates of sensitivity to reinforcement immediacy; in most cases, this effect occurred without a change in overall response rates. In many cases, the reduced sensitivity to reinforcement delay produced by d-amphetamine resulted primarily from a decrease in the asymptotic level of preference achieved within the session; in some cases, d-amphetamine produced complete indifference. These findings suggest that a reduction in the sensitivity to reinforcement delay may be an important behavioral mechanism of the effects of psychomotor stimulants.     

Stereotyping and victim blaming of individuals with a laryngectomy

This study examined whether individuals with a laryngectomy are at risk for stereotyping and victim blaming. Undergraduate students (3 men and 41 women) volunteered to listen to a recording of a man who used tracheoesophageal speech or a man who was a typical adult speaker. A written vignette was provided prior to the listening activity to assess whether knowing that the speaker did or did not have a history of smoking affected the listeners' judgments of the speaker. Semantic differential data and qualitative responses indicated that participants did not report victim blaming; however, they did report that users of tracheoesophageal speech were less highly employable than typical adult speakers. Participants also indicated they relied on the vocal characteristics of speakers and used empathy- or experienced-based reactions to make judgments about users of such speech.     

On the minimization of task switch costs following long-term training

Flexible, context-dependent linkages between stimulus and response are fundamental to adaptive behavior. In the present article, we evaluate the limits of this flexibility by exploring the asymptotic efficiency of people’s ability to switch between two different sensorimotor mappings. Two stimulus—response (S—R) mappings were learned, either both on the same hand (unimanual condition) or one mapping per hand (intermanual condition). The S—R mappings presented bivalent stimuli and employed the same response keys. A novel training regimen successfully reduced task-switch costs to approximately 20 msec, suggesting that residual switch costs cannot be eliminated. These costs cannot be entirely attributed to the cognitive control process of task-set reconfiguration, because they are observed over cued switch intervals of several seconds. Two additional issues in motor learning were addressed: the single or dual loci of manual motor control and the coordinate system of task representation. First, the results favored the notion of independent controllers for each hand instead of a single dominant controller, since intermanual performance was superior to unimanual performance. Second, a transfer task tested internal (egocentric) and external (allocentric) coordinate systems. Transfer was more effective using the external coordinate system, suggesting that the S—R mappings reflected the association between the bivalent stimuli and external goals (i.e., the individual keys) rather than the concrete pattern of muscle contractions (i.e., the finger pressing the key). Finally, retention tests revealed that these learned S—R associations were remarkably durable, since no decrements in fluent task-switching performance were observed after 10 months without practice.     

GENDER, JOB AND FAMILY CONDITIONS, AND PSYCHOLOGICAL SYMPTOMS

This study examined the hypothesis that gender differences in psycho-logical distress are mediated by job and family role conditions. Previous research has failed to directly test such mediational hypotheses but rather has inferred effects of role conditions from simple role-occupancy variables. The sample consisted of full-time employed married respondents including 161 women with full-time employed spouses, 142 men with nonemployed spouses, and 126 men with full-time employed spouses. Although the sample reported low psychological symptomatology overall, the women in dual-earner families reported more psychological symptomatology than did either group of men. Hierarchical regression equations indicated that work and family conditions fully attenuated this gender differential. Women in dual-earner families also reported less job enrichment, less time at work, and more household labor inequity than did either group of men. They also reported more childcare difficulty than did men with nonemployed spouses. Work-family interference predicted psychological symptomatology and partially accounted for its relationship with some job and family conditions. We discuss processes through which gender affects psychological distress.     

“Pretend you didn't know”: Preschoolers' talk about mental states in pretend play

Fifty preschoolers (mean age = 47 months; SD = 5 months) were recruited from local inner-city nurseries to take part in a study of early friendships and the development of social understanding. Friendship pairs (10 boy-boy pairs; 10 girl-girl pairs and 5 boy-girl pairs) were filmed playing together for 20 minutes in a quiet room supplied with toys and dressing-up materials. The videos were then transcribed and coded for mental-state talk and pretend play. The children were also given a battery of tests tapping theory-of-mind skills and verbal ability. The results indicated a strong association between children's engagement in pretend play, and the frequency and nature of mental-state talk. This association is discussed in relation to (1) effects of context, (2) individual differences in children's understanding of mind and verbal ability, and (3) the social nature of pretend play.     

Origins of children's career aspirations: II. Direct suggestions as a method of transmitting occupational preferences.

Analysis of responses of 576 children in kindergarten and Grades 2, 4, and 6 in both public and private schools shows direct suggestions particularly from significant others are recalled increasingly frequently as children grow older. Children, however, are less likely to select suggested occupations with age. These data do not account for high aspirations of children to parental occupations.     

A microcomputer-based cardiotachometer with video display

A KIM-1 single board microcomputer implementation of a cardiotachometer that provides a low-cost versatile heart-rate data acquisition system is described. Unique features include telemetry, a composite video output signal of a video frame displaying elapsed time and heart-rate, and a TV camera signal of the behavior. Data is videotape- and/or audiotape-recorded for further analysis with a larger computer.     

Differential production of positive and negative discriminative stimuli by normal and retarded children

Using an observing procedure similar to Wyckoff's (1969), two normal and two mentally retarded children were studied. The children were initially trained to earn pennies by pressing a rectangular key according to a multiple variable-interval extinction schedule of reinforcement. After discrimination training, the children were allowed to produce the discriminative stimuli by depressing a second or observing key. The retarded children were different from the normal children in that they produced more of the positive discriminative stimulus (S+) than the negative discriminative stimulus (S?). In the case of the retarded children, S+ observing started high and remained high. In the case of the normal children, S+ observing was initially substantial and then rapidly diminished.