Effects of retention interval and modality on sensory and semantic trace information

Subjects studied a long list of individual words that were presented either visually or auditorily. Recall was tested immediately or after a filled delay by using either word endings or taxonomic categories as extralist retrieval cues. Two interactions were of particular interest. First, word ending cues were just as effective as taxonomic cues on the immediate test. On the delayed test, however, ending cues were less effective. This result suggests that sensory information encoded about a word decays at a faster rate than semantic information. Second, although modality had no observable influence on the taxonomic cues, word ending cues were more effective when all items were shown visually than when they were presented auditorily. Taken together, these findings indicate that the visual features of words are encoded at study and that this information can be accessed during test if it is recapitulated by the retrieval cue shortly after acquisition.     

Coactor's behavior and imitative aggression

After being exposed to either an aggressive or a nonaggressive filmed model, four- and five-year-old boys were tested for imitation while either alone or with a confederate who had also seen the film. The confederate's behavior was either inactive, the same as that in the film, the same as that in the film the child had not seen, novel but of the same category (aggressive or nonaggressive) as that in the film seen, or novel but in the category of the film not seen. These conditions conformed to the dimensions of a 2 × 6 factoral design. According to prediction, the imitation of subjects exposed to the aggressive model was greatest when the confederate's behavior was similar to the model's. No difference in imitation was produced by the confederate's actions if the boy had watched the nonaggressive model. The results were interpreted within the context of social comparison theory.This project was facilitated by the senior author's Margaret Bosshardt Pace and Paul David Pace Research Fellowship.     

PDP-12 stimulus control and data collection for lateralized discrimination learning

A BASIC program that requires a minimum 8K core, 32K disk, KW12-A real-time clock, eight extended operation eight-mode DEC relays with peripheral interface, and user-generated special-function assembly language subroutines for clock and relay control was prepared, using advanced OS/8 BASIC, for conducting laterality studies. It is assumed that the user’s system has a dual tape drive. CRT, and Teletype. Modified IEE readouts have been used for stimulus presentation. Laterality effects and results suggesting application of the procedure in clinical neuropsychological testing have been achieved. This paper describes the rationale for development of the task, summarizes administration procedures, and provides flowcharts of the BASIC program and assembly language special functions, as well as a circuit diagram for the peripheral relay interface.     

Child performance on discrimination tasks: Effects of amount of stimulus variation

Two independently conducted studies investigated stimulus variation effects on children's discrimination learning. The stimuli in the first study were generated by a conjunctive rule and were presented in pairs. Mean trials to criterion was significantly lower for the single-feature change treatment (17.4) than for the multiple-feature change treatment (29.9). Single-feature change-treatment transfer scores were significantly higher only for stimuli that differed in terms of one of the features. The second study not only replicated the initial finding concerning the single-feature change treatment but also found that students made more errors in reaching criterion when stimuli were generated by an exclusive disjunctive rule and were presented singly. For all tasks, the single-feature change treatment with stimuli presented in pairs was accompanied by fewer errors to criterion than the other treatments.     

Differences in the search rate of children and adults in short-term memory

When people recognize a test item as belonging or not belonging to a previously presented set, recognition latency increases with the number of items in the set. Although some evidence suggests otherwise, it is currently held that the rate of this increase is the same for children and adults. In contrast, the present experiments indicated a much slower search rate for second graders (mean age = 7.33 years) than for seventh (mean age = 12.50 years) and twelfth graders (mean age = 17.25 years). Moreover, search rate for second graders was invariant under instructions which did or did not emphasize speed and with presentation of the memory set in either the auditory or visual modality. Experiment II showed that the slow search rate for children was not due to differences in encoding between children and adults.     

Effects of false increasing,decreasing, and true electromyographic biofeedback on the frequency of stuttering

Adult stutterers received auditory feedback of laryngeal area muscle activity while reading aloud under three conditions: (1) False Increasing Feedback, (2) False Decreasing Feedback, and (3) True Feedback. The subjects were unaware that the feedback in two conditions was being altered and were instructed not to manipulate the feedback signal. Decreases in the frequency of stuttering were observed for both the false increase and true feedback conditions. Factors contributing to the effectiveness of biofeedback techniques with stutterers are discussed.     

Stage 2 processing and the divided-attention effect

In two experiments subjects performed a choice-reaction-time (CRT) task and a second task concurrently. The second task was a simple reaction-time task in Experiment 1 and sentence generation and recall tasks in Experiment 2. Both studies yielded two main findings: Performance of the second task was not affected by CRT memory load (one, two, or four items), and the requirement to perform the second task did not affect the rate of increase of CRT with memory load. The first finding indicates that the effect of memory load on CRT is attributable to memory scanning, or Stage 2 processing, and is not an artifact of the rehearsal demands of the CRT memory set. The second finding indicates that Stage 2 processing is not sensitive to division of attention between the CRT and a second task.     

Modification of impulsive tempo in learning-disabled pupils

Thirty-three impulsive learning- disabled males, aged 9–12 years, were assigned to one of three treatment conditions: (a) Modeling, in which subjects were exposed to a videotape of a boy demonstrating reflective problem-solving activities and instructing himself to perform cautiously; (b) Modeling Plus Self-Verbalization, in which subjects observed the same videotape and were additionally required to verbalize similar reflective instructions; and (c) Control, in which subjects were shown a videotape of the task materials used in the modeling videotape, but without the model. Subjects were tested immediately after exposure to treatment, and again 3 weeks later, on different forms of the Matching Familiar Figures test. Both Modeling and Modeling Plus Self-Verbalization conditions were superior to Control in reducing errors on the immediate test, but the three treatments did not differ on the delayed test. No significant differences among the three conditions were found with regard to response latency. Discrepancies between the present results and those of previous related studies were noted, and potential research directions were suggested.The authors appreciate the cooperation and support of Mr. Dan Hurd, superintendent of DeKalb County Special Education Association.