The effects of distributed training on retention of operant conditioning in human infants

Long-term retention of operant footkicking acquired in the mobile conjugate reinforcement paradigm was assessed as a function of the distribution of training time. In the first study, 3-month-old infants were trained for either one 18-min session or for two 9-min or three 6-min sessions separated by 24-hr intervals. All infants exhibited retention during a test administered immediately after training, but only those trained in a single session continued to perform the conditioned response during cued-recall tests 7 or 14 days later. Infants trained in three sessions showed no evidence of remembering the contingency even after a week. A warm-up decrement, seen in the day-to-day performance of infants in the distributed conditions, was eliminated in the second study by the interpolation of a nonreinforcement period at the outset of daily sessions. This procedure also enhanced long-term retention such that infants trained in three 6-min session now remembered the contingency for 14 days and did not differ from infants who had received a single 18-min session. Whether distributed training facilitates or impairs long-term retention appears to depend on the opportunity for infants to acquire a sufficient number (or kind) of effective retrieval cues during original learning.     

Discrimination and generalization by rats of temporal stimuli lasting for minutes

In three experiments, rats learned to respond differentially to reinforced and nonreinforced trials when the length of the intertrial interval (ITI) predicted the trial outcome (reinforcement or nonreinforcement). Rats in control groups, for whom the length of the ITI did not predict the outcome, did not show differential performance on nonreinforced and reinforced trials. Generalization gradients obtained following discrimination training were comparable to those obtained following discrimination training with other types of discriminative stimuli. That is, groups which had shown differential performance in discrimination training yielded generalization gradients with fastest speeds at the previously reinforced ITIs, slowest speeds at the previously nonreinforced ITIs, and intermediate speeds at ITIs of intermediate length. Control groups yielded flat gradients across all ITIs tested. These effects were shown for relative time discrimination (short time = reinforcement, long time = nonreinforcement, or the reverse) and also for an absolute time discrimination (long and short time = reinforcement, middle time = nonreinforcement or the reverse). This method was effective for time duration measured in minutes rather than seconds, as is more commonly the case.     

Dynamic processes in music perception

A schema-based theory of music perception that describes the dynamic interaction between the musical event and the listener’s knowledge of the underlying regularities in tonal music is proposed. Three properties of musical schema are evaluated in a recognition memory experiment: (1) The schema engages a subset of the abstract knowledge system that is determined by the predominant key of the musical sequence, (2) the schema evaluates both interval relations and the functions of the sounded elements within the established tonal framework, and (3) the schema interacts continuously with the musical event in time to process pitch information in its temporal context. Listeners are required to identify the serial position of a chord that is changed between two successive chord sequences that are otherwise identical. The experiment measures the magnitude and the temporal extent of the disruptive effect of including in the sequence an element outside the tonal framework. The results show temporally specific effects on memory for pitch relations consistent with the operation of a musical schema. Comparisons are made with schema-based theories applied in other perceptual and cognitive domains.     

Human figure drawings of gender-problem children: A comparison to sibling,psychiatric, and normal controls

The Draw-a-Person test was used to evaluate a number of questions regarding children referred for potential problems in their gender-identity development (N = 36). Sibling (N = 31), psychiatric (N = 23), and normal (N = 30) children served as comparison groups. The major results included the following: (1) The gender-referred children were more likely to draw an opposite-sex person when requested to "draw a person" than were the other three groups; (2) the gender-referred children who drew an opposite-sex person were more likely to play with opposite-sex toys and dress-up apparel on a free-play task than were the gender-referred children who drew a same-sex person; (3) the gender-referred children drew taller opposite-sex persons than same-sex persons; (4) using Koppitz's (1968) criteria, the normal children had a smaller proportion of emotional disturbance indicators in their same-sex drawings than did the other three groups. These findings were discussed with regard to psychometric and interpretive issues in the assessment of children with atypical gender-role behavior.     

Working through a group's fantasy of the deceased leader's wish for the group's continuation

This paper reflects the working through of a group's fantasy that the deceased group leader wished the group to continue. As in any defense, the fantasy protected members from the pain of the finality of the leader's death. This article reveals the subjective experience concerning the effect of the leader's death on the group and members' intrapsychic struggle to separate and individuate from the deceased leader, while attending to and striving toward the group's continuation. The group's painful and growing individuation enabled the group to follow its own tasks without the spector of the deceased leader.     

Smoking cessation with behaviour therapy or acupuncture—A controlled study

Five hundred and fifty-eight cigarette smokers (mean 31 cigarettes/day) were randomized in four groups: Acupuncture, Behaviour Therapy, Placebo Medication and Waiting-list Control. The life-table analysis of smoking cessation showed, at a 12-month follow-up, no difference between Acupuncture, Behaviour Therapy and Placebo. Differences appeared only in an analysis of the abstinent subjects at each data point. Behaviour Therapy and Acupuncture accounted for significantly more abstinent subjects than Placebo at the end of the 2-week therapeutic phase. However at 9 and 12 months Acupuncture had a statistically-significant greater number of abstinent subjects than Behaviour Therapy, but there was no difference between Acupuncture and Placebo. The percentage decrease in smoking from baseline appeared significantly greater at 12 months in the first three groups than in the Control conditions. However, as in most smoking-cessation studies, the overall effect was small and non-specific. The results reflect the importance of maintenance programmes and of the prevention of addiction.     

Peripheral visual changes and spatial attention.

Three experiments are reported investigating the attentional effects of peripheral visual changes. In agreement with previous work, experiment 1 demonstrated facilitatory and inhibitory effects of a peripheral visual change on the latency of peripheral target detection. However, after a few minutes practice the facilitatory effect disappeared entirely. The inhibitory effect, though slightly reduced in later blocks, remained significant. Hence, the two effects are dissociable and not inter-dependent as argued by Maylor (1985). In experiments 2 and 3 the perceptual salience of the peripheral cue was manipulated. With a low energy, barely noticeable cue there was no reduction in either facilitation or inhibition as a function of practice. In contrast, the attentional effects of cues higher in energy tended to diminish with practice. Theoretical implications of these data are discussed.