An examination of vicarious reinforcement processes in children

The primary purpose of the present investigation was to examine vicarious reinforcement processes in children. More specifically, the effects on one child of observing another same-sex child receive direct reinforcement were explored across three different age levels. Subjects were 216 children, randomly assigned to experimental or control conditions. For the control condition, neither child in the same-sex, same-age dyad received reinforcement for performance on the experimental task. For the experimental condition, one child in each dyad received direct social reinforcement for performance, while the other child received no social reinforcement for similar performance. Although children who observed other children receive direct social reinforcement initially increased performance (as predicted by vicarious reinforcement hypotheses), their performance soon decreased and was characterized by verbal and nonverbal responses which appeared to interfere with task performance (e.g., “Hey, I can do them too”, “Look at mine”, “There's no use in trying”). It appeared as if these observing children were being punished for their performance. Such effects were more pronounced for older than younger children; however, they were observed equally in boys and girls. Results were discussed in terms of vicarious reinforcement and “implicit punishment” hypotheses. Implications for applied settings were also addressed.     

Hemispheric alpha asymmetries during an electromyographic biofeedback procedure for stuttering: A single-subject experimental design

A single-subject “double-reversal” experimental design was used to investigate the use of electromyographic (EMG) biofeedback on the dysfluent behaviors of a right-handed male stutterer. A systematic decrease in EMG amplitude accompanied a progressive approximation of increased verbal complexity resulting in increased fluent behavior. Electroencephalographic (EEG) alpha data (8–12 Hz) gathered during baseline and pre- and post- treatment sessions appeared to co-vary with changes in fluency with right hemispheric suppression associated with greater dysfluencies and left hemispheric alpha suppression with decreased dysfluencies. The results are discussed relative to stutterer's adoption of differing behavioral production strategies for fluent speech that are associated with hemispheric information processing strategies.     

Soft tissue anatomy of the tongue and floor of the mouth: An ultrasound demonstration

Ultrasound technology has not been used extensively in the study of normal and abnormal oral physiology and speech. Features such as soft tissue detail, real-time motion display, and subject safety make ultrasound ideal for imaging the tongue and the floor of the mouth. This study demonstrates visualization of the muscles of the tongue and floor of the mouth for a normal subject using ultrasound imaging. By employing submandibular transducer placement of real-time sector scanners, tongue anatomy and motion were continuously visualized in sagittal or coronal planes. In addition to the entire tongue surface, much of the intrinsic anatomy was identified including: the genioglossus, geniohyoid, mylohyoid, and digastric muscles; fascial boundaries such as the median fibrous septum, floor intermuscular septum, and paramedian septums; and the hyoid bone. A tongue excised from a human cadaver was scanned using ultrasound and dissected to confirm the anatomy seen in the live tongue. Tongue surface shape and configuration of the intrinsic tissue structures were observed and compared for the phonemes /k/, /u/, and /i/. Anatomical landmarks in the resting and speaking tongue are discussed as well as applications in the fields of speech science and speech pathology.     

Tracing memory-structure activation during person judgments

The purpose of the reported research was twofold: (a) to introduce a procedure for measuring concept activation during memory-based decisions and (b) to employ the procedure to investigate memory-activation processes in social judgments. Recent research has focused on subjects' reliance on memory for earlier inferred categorizations as the basis for judgments about persons. However, subjects have also been shown to rely on memory for factual information when making such decisions. To more fully understand how social judgments are made, methods are needed that are capable of tracing concept activation during the judgment process. The present study introduces a procedure that relies on probe recognition speed as a measure of concept activation. The procedure is used to examine alternative models of how subjects activate categorical and event memory when making contemplative impression judgments (i.e., judgments that they have to justify). The results favor a dependent memory-activation model that hypothesizes subjects activate both facts and earlier categorizations that they have made about a person when making subsequent memory-based judgments. Memory-structure activation was dependent in that facts relevant to forming the early categorizations were more likely to be activated in the service of a judgment than category-irrelevant facts. Advantages and limitations of the probe procedure as a measure of memory-structure activation during decisions are discussed.     

On the consequences of priming: Assimilation and contrast effects

Two experiments investigated the effects of priming (activation of a category by unobtrusive exposure to exemplars of that category) on subsequent judgments in an unrelated task. Subjects were primed with one of four levels of ferocity (size) in the course of a “color perception” experiment, and were later asked to judge the ferocity (size) of real (unambiguous) and unreal (ambiguous) animals. An interaction between ambiguity of judged stimuli (real vs unreal animals) and extremity of primed exemplars (moderate vs extreme levels of ferocity or size) was revealed. Assimilation effects (judgments consistent with the primed category) occurred only when moderate exemplars were primed and ambiguous stimuli judged. Contrast effects occurred when extreme exemplars were primed and ambiguous stimuli judged and, irrespective of extremity of the primed exemplar, when unambiguous stimuli were judged. The results are interpreted in terms of an integration of social judgment and social cognition perspectives.     

A note on the "word-order problem" in agrammatism

This brief note has two parts. First, it presents an analysis of the ability of English agrammatic patients to assign the thematic roles of agent, instrument, theme, and locative to noun phrases in active and passive sentences and prepositional phrases. Data regarding this ability have been presented by Schwartz, Saffran, and Marin (Brain and Language, 10, 149-262 (1980) regarding comprehension, and by Saffran, Schwartz, and Marin (Brain and Language, 10, 263-280 (1980) regarding production. These authors claim their data show that English agrammatic aphasics do not map "word order" onto thematic information. However, a very simple set of principles accounts for all their results, including results which are discrepant in their treatment, but requires that English agrammatics assign thematic roles to NPs in part by virtue of the position of an NP in a sentence or a phrase. In the second part of this note, several issues raised by this re-analysis are briefly discussed.     

Qualities of color vision in infancy.

Four-month-old infants attended differentially to eight equally bright, monochromatic spectral lights; that is, they discriminated colors. Moreover, infants showed the same pattern of differential attention regardless of experimental group (different groups of infants saw different subsets of all possible pairings of colors) or experimental method (paired comparisons or single stimulus). In general, the differential attention of infants to colors parallels the ratings of the pleasantness of those same colors by adults. Finally, infants looked significantly longer at color category centers than at color category boundaries. These results suggest that looking at this early stage of infancy can better be understood in terms of preference rather than in terms of stimulus categorization. The results also provide further evidence for a neural excitation model of early visual attention.     

Transfer of a response controlling stimulus duration across discrimination problems

In the acquisition phase, pigeons learned to peck at a changeover key to shorten the duration of S? but not of S+ presented on the food key in a discrimination problem. In the transfer phase, the significance of S+ and S? was changed through extinction of both, equal reinforcement, or discrimination reversal, while the changeover key was not available. Transfer tests then showed appropriate modification of the changeover response. Similar transfer was demonstrated across orthogonal stimulus dimensions. Further analytic studies showed that this transfer of the changeover response did not depend upon mediation due to differential response rates to the food key. This research strategy enriches the study of the “second learning process” by providing an indicator of stimulus control in all phases of the procedure. Direct transfer between different problems also indicates that discriminative stimuli, although physically dissimilar, have the same “psychological value” for the subject.