The importance of subject control in reinforcing brain stimulation

A comparison between the reinforcement strength of self-administered and externally imposed brain stimulation was undertaken. Rats performed on a chain schedule in order to receive brain stimulation, either selfadministered or imposed, during the second component of the chain. Response rates during the first component of the chain schedule indicated that self-stimulation was more reinforcing than imposed stimulation. In addition, contrast, both positive and negative, seemed to be present. It was concluded that reinforcement strength may be enhanced when the subject controls the presentation of reinforcement.     

A study of some conditions relating to the retarded adult's stereotyped responding in a binary-choice task

This study was a longitudinal one that examined the effects of certain conditions on alternation and perseveration in a binary-choice task. The conditions manipulated included: (1) lapse of time (stability of the pattern), (2) stimulus dissimilarity, (3) spatial location of the two alternatives, (4) time-out (time away from the task), (5) delay between responses, and (6) differential reinforcement of the two choices. Eight mentally retarded adults, identified as “pure” alternaters or perseveraters, served as subjects. Perseveration was “disrupted” only by differential reinforcement. Alternation was affected by all experimental manipulations with the exception of stimulus dissimilarity.     

Recognition memory in mentally retarded persons

The continuous recognition memory of retarded and normal subjects was assessed. The stimuli were magazine pictures, arranged so that lags of up to 250 pictures occured. The overall performance of the retarded subjects was poorer, in terms of hit rate or d′. However, the differences were present at 0 lag and the slopes of the forgetting curves were similar in both groups. It was concluded that differences between these subjects were due to a perception related process and not to memory.     

Do the mentally retarded have poor memory?

The hypothesis that mentally retarded persons have a short-term memory deficit whixh is due to inadequate rehearsal strategies is reexamined. A reevaluation of results of a number of experiments suggests that normal and retarded persons differ on short-term memory tasks, and the superiority of normals is present from the time of initial stimulus exposure. While some evidence for slope differences in retention curves is found in a few tasks, it is not strong support for memory differences. The hypothesis that “memory” differences are due to differential encoding as a result of more adequate rehearsal by the normal subjects is unacceptable. If this were the case, some differences in slope of retention curves could be expected unless rehearsal beyond the encoding stage was totally precluded. The review points to a need for an empirical reevaluation of the issue with a full recognition that deficits in particular processes may characterize some retarded persons and not others.     

Category similarity effects in children's semantic memory retrieval

Fourth-, sixth-, and eighth-grade students were required to indicate whether or not a stimulus word belonged in either of two semantic categories that were held in memory. Each category pair was either semantically similar or semantically dissimilar. The results indicated that even for the youngest children, similar categories required less search time than dissimilar categories. It was suggested that while dissimilar categories had to be accessed successively prior to search, subjects were able to consolidate similar categories into a superordinate group which eliminated the time to shift from one category to another during search. The results were contrasted with clustering studies which have demonstrated a minimal amount of memory facilitation in children for conceptually related items over unrelated items.     

The sufficient conditions for directed forgetting in normal and educable mentally retarded adolescents

A series of studies investigated the conditions under which normal and educable mentally retarded adolescents (13 to 15 years old) would or would not disregard irrelevant information in memory. A directed forgetting task was used in which the person was required to recall short sequences of picture names. In some sequences there was a cue to forget the first few pictures (irrelevant information) and to remember only the subsequent pictures (relevant information). When normal adolescents were given no explanation of the forget cue, there was interference from the irrelevant information. A minimum explanation of the cue, however, was sufficient to eliminate interference for the normal adolescents. The same minimal explanation was not sufficient for mentally retarded adolescents. It was clear that irrelevant information in memory interfered with the performance of retarded adolescents given only a minimal explanation of the forget cue. These results are important since most naturalistic situations do not involve an elaborate explanation of the importance of disregarding irrelevant information previously stored in memory.     

Task instructions and strategy transfer in the directed forgetting performance of mentally retarded adolescents

The influence of task explanation on strategy transfer was studied in educable mentally retarded adolescents (13 to 15 years old). A directed forgetting task was used in which the person was required to recall short sequences of picture names. In some sequences there was a cue to forget the first few pictures (irrelevant information) and to remember only the subsequent pictures (relevant information). During the first session the amount of explanation given the directed forgetting task was varied, and during the second, some of the subjects were trained to rehearse in a simple sequential memory task. Transfer of training was then examined on a retest of the directed forgetting task. The majority of subjects trained to rehearse and given a minimal explanation of the directed forgetting task maintained the strategy on trials which were identical to those used during rehearsal training, but failed to generalize the strategy on other trials. The results indicate that providing a full explanation of the task requirements does not assure strategy generalization, but providing only a minimal explanation makes strategy generalization unlikely.     

Cue selection in verbal discrimination learning of retarded subjects.

A series of experiments was conducted to examine cue function in trigram verbal discrimination learning by retarded subjects. The issue was to determine the factors that control attention in this type of learning situation. The two variables of chief interest were trigram meaningfulness and reinforcement history. The major general conclusion was that retarded subjects employ complex cue selection strategies in solving a verbal discrimination involving compound verbal stimuli. Major findings were as follows: (a) Retarded subjects exhibit a response bias in favor of words over nonsense trigrams; (b) relatively little active cue selection based on meaningfulness was observed; (c) a compound stimulus discrimination was more difficult to learn than a discrimination involving single verbal stimuli; (d) compound and single stimuli may be processed differently in original discrimination learning; (e) cue position probably controls attention in compound discrimination learning; and (f) a frequency theory of verbal discrimination learning is supported by these data.     

Facilitation of retention by white noise.

Second and fifth grade subjects were given three verbal tasks: serial, free recall, or paired-associate learning. Retention tests were administered immediately after the acquisition phase or following a long delay. Half the subjects were exposed to a 2-min period of bursts of white noise (arousal) immediately prior to the retention test. The finding of primary interest was that white noise produced substantial improvement in performance relative to a control condition. This effect may be more pronounced for long-term memory than for short-term memory. Although older children exhibited better long-term memory than younger subjects, no interaction of age with arousal condition was observed.     

Focal changes in cerebral blood flow produced by a test of right-left discrimination

A sensorimotor control activation task was used to isolate the focal cerebral blood flow changes resulting from the visual and cognitive processing of a right-left discrimination task. Eleven normal right-handed males participated. The sensorimotor control task produced significant bilateral increases in flow in most cortical channels. Significant bilateral parieto-occipital activation was found for the right-left discrimination task over and above the flow changes produced by the sensorimotor control task. The left occipital flow increase resulting from the right-left discrimination task was found to be negatively related to task performance. An inverse relationship was also found between WAIS Performance IQ and the blood flow change in the left parietal channel. These results suggest areas for further testing concerning potential individual differences in cognitive processing during the performance of a right-left discrimination task.     

Toward a reconceptualization of the reciprocal imitation phenomenon: Two experiments

This paper reports two experiments which consider the increased imitation exhibited by models who have been imitated. Experiment 1 was concerned with whether the reciprocal imitation effect is really reciprocal or if the subsequent imitation will generalize to someone else. It was found that adult subjects who were previously imitated at the 75% rate on a perceptual judgments task subsequently imitated their partner more, rated their partner more attractive, and felt more confidence when imitated than did subjects imitated at the 25% rate. These results were obtained regardless of which confederate the subjects imitated, thus indicating that reciprocal imitation is not necessarily reciprocal, but is generalizable. Experiment 2 assessed whether the subsequent imitation is the product of the effects of being imitated or is the result of the subject observing the imitator's imitation. The results indicated that after having observed imitation at a 75% rate, adult onlookers are more likely to subsequently imitate and be attracted to the imitator, the imitated person, and a person new to the situation than are onlookers who observed a 25% imitation rate. A theoretical modification is advanced which holds that subsequent imitation effects, whether from observing others imitate or from being the target of the imitation, result from a process of imitation of imitativeness. The results of these two experiments have implications for theory in imitation and social learning.     

Effects of threatening and reassuring components of fear appeals on physiological and verbal measures of emotion and attitudes

Physiological processes are integral components of (a) many conceptualizations of emotion, (b) the emotion of fear, and (c) the fear-as-acquired-drive model of attitude change. Nevertheless, few studies of fear and persuasion have simultaneously measured self-reports of fear and autonomic activity. The present factorial experiment manipulated high versus low fear and high versus low reassurance and monitored self-reports and cardiovascular and electrodermal activity. The results disclosed that heart rate (HR) and skin conductance (SC) were highly correlated (r = .70). Although the multiple correlation among HR, SC, and a self-report measure of fear was a modest .44 (p < .05), additional evidence suggested that self-reports were the most sensitive measure of the construct of fear. The fear-film manipulation, which is typical of many fear-arousing communications, had identical effects upon the autonomic and self-report measures of fear. These data support the construct validity of the self-report measure of fear and increase our confidence that “fear” has been aroused in previous studies of fear and persuasion. Neither the fear-film manipulation nor the autonomic components of fear were associated with attitude change. The reassurance variable facilitated attitude change. Overall, the findings emphasized the importance of cognitive mediational processes rather than an emotional state of fear.     

The use of averaged electroencephalic response techniques in the study of auditory processing related to speech and language

This paper reviews a number of studies done by the authors and others, who have utilized various averaged electroencephalic response (AER) techniques to study speech and language processing. Pertinent studies are described in detail. A relatively new AER technique, auditory brainstem responses (ABR), is described and its usefulness in studying auditory processing activity related to speech and language is outlined. In addition, a series of ABR studies, that have demonstrated significant male—female differences in ABR auditory processing abilities, is presented and the relevance of these data to already established differences in male—female language, hearing, and cognitive abilities is discussed.     

Focal changes in cerebral blood flow produced by monetary incentive during a mental mathematics task in normal and depressed subjects

The purpose of this experiment was to determine the effect of incentive-induced arousal on the diffuse and regional cerebral blood flow (rCBF) response during cognitive activation for normal and depressed groups. Two normal rest CBF measurements were followed by two mental mathematics activation CBF measurements. For the first activation measurement, half the subjects in each group were offered monetary incentive for correct performance and half the subjects received no monetary incentive. All subjects were offered monetary incentive on the final activation run. The effect of monetary incentive on the first activation run was to increase CBF activation at four detectors in the left hemisphere. Incentive did not affect the CBF activation response when introduced following practice on the activation task (on the final run). Depressed groups had lower resting blood flow than normals, but the distribution of flow and the CBF response to incentive were almost identical in the two groups.     

Forgetting in retarded and nonretarded persons under conditions of minimal strategy use

Short-term memory processes of mentally retarded (mild, moderate, and severe) and nonretarded persons were compared in a delayed matching-to-sample task that minimized the use of verbal rehearsal. In addition to trials with delays up to 20 s, the inclusion of trials on which the sample and comparison stimuli occurred simultaneously made it possible to isolate memory and discriminability. Forgetting was most pronounced between the simultaneous and 0-s conditions, and nonretarded subjects forgot less than retarded subjects between these conditions. There were no group differences beyond the 0-s delay. Ease of strategy use failed to account for individual differences, and reported strategy use was not related systematically to performance. These findings are incompatible with the hypothesis that normal-retarded differences occur only on tasks involving effortful cognitive strategies. Differences between nonretarded and retarded groups in this study may be due to a failure in automatic encoding processes in retarded persons.     

Managerial aspirations of high school seniors: A comparison of males and females

Empirical research in the past has indicated that young people are generally not oriented toward managerial careers and that females are less so than are males. However, the greater career orientation of today's students, recent changes in societal values, persistent attempts by women to obtain equality, and federal legislation expressly forbidding discrimination may have changed this situation by the late 1970s. A survey of 2112 high school seniors in the state of Alabama was conducted to investigate these issues. Results indicate that few high school seniors aspire to management careers and that sex continues to be a major discriminator. The “male managerial model” continues to be reinforced by the values and attitudes of society as reflected in its young people.