Arousal and memory: phasic measures of arousal in a free recall task.

EEG alpha activity and skin potential were monitored during word presentation in a single trial free recall task. Phasic changes in EEG alpha and skin potential, co-occurring with word onset, were positively related to recall at an immediate retention interval (2 min) but not after a delay (45 min). The results were interpreted as supporting the extension of Routtenberg's (1968) two-arousal system hypothesis to human memory. Arousal was viewed as affecting memory during the attribute encoding stage of memory storage.     

Perceptions of the magnitude and diversity of social support

Three studies were conducted to test the hypotheses that subjects would overestimate the proportion of their peers who shared their opinion on an issue and that they would perceive their own opinion group as consisting of people with a wider and more diverse range of values and outlooks than those holding different opinions. The first study was conducted following a period of intense debate about sixism on a college campus. Subjects estimated student opinion on issues related to sexism and indicated how diverse or similar they perceived supporters and nonsupporters of the women's movement to be. In a second study subjects estimated the proportion of students who evaluated President Carter's performance as good, fair, or poor and then indicated how diverse or similar the three groups of students were who held these various opinions. A third study closely replicated the second, using the issue of divestiture of college-owned stock in South Africa. In all three studies, subjects were divided into groups on the basis of their own attitudes. Results consistently supported the hypotheses.     

The perception of consistency in attitudes

A study was conducted to test the hypothesis that when people change their attitudes they reduce the dissonance associated with the inconsistency of their new and previous positions by distorting their recall of their initial stand to make it consistent with their new attitude. Small groups of high school students discussed bussing, one of 30 pretested issues. An experimental confederate participated in each session with the task of effecting attitude change. After the discussion, the subjects' new attitudes were assessed and they were asked to duplicate their pretest scores. The results confirmed the hypothesis. Subjects distorted their recall of their initial stand on bussing so as to make it consistent with their new attitude. Such distortion allows persons to feel that their new position is the one they have always held. The subjects made such recall errors only on the bussing issue. Control subjects did not distort their original bussing attitudes.     

The attribution of friendliness

A study was conducted to explore attributions of friendliness resulting from live interaction. Subjects had either one or two encounters with a confederate whose behavior in each encounter was either friendly or unfriendly and was either spontaneous or forced by role requirements. Single encounter subjects formed impressions of the confederate that reflected the friendliness or unfriendliness of the confederate's behavior but these impressions were not modified by their knowledge that the confederate's behavior was freely chosen or forced. The same was true for subjects who had two friendly or two unfriendly interactions with the confederate. Subjects who found the confederate to be friendly in one encounter and unfriendly in the other formed impressions that took into account the causes of the confederate's behaviors. In general, these subjects modified their impressions according to the cause of the confederate's behavior in the second encounter.     

Homonym understanding and conservation

It is proposed that a common cognitive capacity underlies both homonym understanding and conservation ability—namely, the capacity to shift attention from one dimension (domain) to another. This hypothesis is tested in a longitudinal study of kindergarten (mean age 6-0) and first-grade (mean age 6-6) children. The results indicate that conservation status is significantly related to homonym understanding, over and above the age or general vocabulary level of the child.     

Children's understanding of sentences with contingent relations: Why are temporal and conditional connectives so difficult?

Children aged 5-, 7-, and 9 were tested on two different tasks to assess their understanding of sentences containing the connectives “when,” “as soon as,” “before,” “after,” “if,” “if-not,” “unless,” and “unless-not.” The results revealed significant improvement between the ages of 5 and 7. This improvement was attributed, in part, to an increased ability to retain information expressed in subordinate clauses. At all age levels, however, the connectives “unless” and “unless-not” were consistently misinterpreted; “unless” was treated as its polar opposite “if,” and “unless-not” was treated as its polar opposite “if-not.”     

A developmental study of the effect of familiarity on short-term visual memory

An attempt was made to specify whether previously reported limitations on young children's full-report capacity lay in a smaller amount of available information, in a shorter trace duration of information in visual information storage (VIS), or in poorer coding of information into permanent storage. Five- and 8-year-olds and adults were shown an eight-item array of figures. followed at varying intervals by an indicator signaling the subject to report the figure to which the indicator had pointed. The effects of three levels of familiarity or “labelability” were examined. While no age differences were revealed in amount of information available nor in the trace duration of information in VIS, strong age differences emerged in coding of information into permanent storage. Data on latency to verbal labeling and familiarity suggested that verbal labeling could not account for the age trends. Rather, the differences seemed to lie in the use of organized visual coding and rehearsal strategies by adults and their relative lack of use by children.     

A developmental study of choice reaction time: the effect of two forms of stimulus degradation on encoding.

To assess the effects of environmental enrichment, 156 normal, full-term institutionalized infants were randomly assigned to Group I (30 min per day of supplementary vestibular stimulation), Group II (30 min per day of supplementary vestibular-plus-verbal stimulation), or Group III (untreated controls). Stimulation began at about the age of 12 days and continued until the children were adopted, approximately 6 weeks later. Children were assessed at regular intervals on the Gesell Developmental Schedules, until the age of 27 months. Group comparisons revealed no significant treatment effects.     

Pigeons' performance under differential reinforcement of low rate schedules depends upon the operant

Pigeons were reinforced with grain for pecking a key or depressing a foot treadle according to differential reinforcement of low rate (DRL) schedules. Birds which depressed a treadle performed efficiently on DRL schedules as high as DRL 35-sec; while birds reinforced for keypecking showed low efficiency under DRL 14-sec. While treadle pressing and keypecking differ along a number of dimensions (including force requirement of the operant and differences in temporal distributions of responses), the present results are consistent with an interpretation based on differences in the degree to which these two responses are elicited by periodic presentations of food.     

TV cameras,public self-consciousness,and mock juror performance

In Chandler v. Florida (1981), the U.S. Supreme Court ruled that the presence of television cameras in the courtroom does not violate a defendant's constitutional right to a fair trial. Since then, several states have expanded their TV coverage rights, and the controversy has intensified. The present study tested opponents' argument that TV cameras distract jurors, thereby reducing their reliance on evidence in the decision-making process. Fifty-one community adults watched a 95-min videotape of a civil trial in the presence or absence of a camera. No effects were obtained on verdicts, awards, or a series of self-report measures. The camera did impair subjects' recall of the evidence, but this effect was dually limited—(a) consistent with an adaptation hypothesis, an initially strong distractive effect gradually diminished, resulting in a net post-trial loss of information that was not statistically significant, and (b) consistent with an individual differences hypothesis, the camera impaired the recall of subjects who were low but not high in dispositional public self-consciousness. These findings were discussed in terms of their practical implications for courtroom management and their contribution to the self-awareness literature.     

Generality of persistence: The role of stimulus and response factors in persistence to punishment

Previous research has shown that intermittent punishment of a response increases its persistence to continuous punishment and that intermittent punishment training in one situation produces persistence to continuous punishment in other situations. Experiment 1 showed that as long as the instrumental response and punishing stimulus were held constant from intermittent to continuous punishment marked differences between these situations had no decremental effect on persistence. Experiment 2 showed that intermittent punishment training of one response resulted in substantial persistence to continuous punishment of a different and apparently incompatible response and that such response change had no more than a marginal effect on persistence. The results were seen as requiring some revision to the traditional conditioning-model interpretation of persistence to punishment.     

Evidence of a detrimental effect of extrinsic incentives on breaking a mental set

College students were either rewarded ($1.50) or not for solving a series of 10 water-jar problems. The first 9 of these were designed to establish a set for a relatively complicated, three-jar solution (B ? A ? 2C). The 10th problem was a set breaker which required that subjects discover a simple (A-C) solution. The mental activities needed to produce a solution to the two types of problems (Problems 1 to 9 and Problem 10) were, therefore, different and one interest was in seeing whether reward would be detrimental for performance on both types of problems. It was not. Poorer reward group performance was obtained only on Problem 10. This result was not due to between-group differences in mathematical ability, and explanations in terms of differences in time taken to check answers or concern over quality of performance were considered and discounted. Measures of intrinsic interest (subject evaluations of the task and a measure of willingness to volunteer for future research) failed to support the belief that interest differences account for performance differences.     

Conditional reasoning following contradictory evidence: A developmental analysis

Recent evidence suggests that young adults do not correctly understand the logical relationship of the conditional (if p the q) as it applies to hypothesis testing, and most training procedures have not been productive. However, the introduction of contradictory evidence following faulty inferences has led to accurate inferences with conditional statements. Third and seventh grade and college studients (9, 13, and 21 years of age, respectively) were tested to assess developmental differences in improvement following contradiction training and to test whether improved performance transfers to other conditional reasoning tasks. Significant improvement in conditional reasoning was found for the young adult group following the introduction of contradictory evidence, and the positive effect of the treatment transferred across tasks. The third grade students showed no effects from the introduction of the contradiction, but the seventh graders were often confused by the introduction of the contradiction. Seventh grade and college student performances were generally worse than that of the third graders for the positive instances (p · q), but while the contradiction training improved college studients' performance it did not affect the seventh graders. The results are discussed in terms of changes in cognitive structures.     

Effects of a concurrent memory task on hemispheric asymmetries in categorization

Recent research on the division of processing between the two cerebral hemispheres has often employed two concurrent tasks to investigate the dynamic nature of hemispheric asymmetries. The experiment reported here explored the effects of two concurrent high-level cognitive tasks (memory retention and semantic categorization) on the direction and magnitude of hemispheric differences in the processing of words and pictures. Subjects were required to categorize words and pictures presented to either the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH). The categorization could be performed while holding either verbal material in memory (digit span), pictorial material in memory (serial nonsense figure recognition), or with no concurrent memory task. The effects produced hemisphere-specific, material-nonspecific interference. The verbal task removed a RVF-LH advantage at word categorization and enhanced a LVF-RH advantage on picture categorization; the pictorial task interfered with picture categorization in the LVF-RH, while enhancing a RVF-LH advantage at word categorization. The results are discussed in terms of multiple resource models of hemisphere function, capacity limitations, and the functional locus of processing required to produce various dynamic hemispheric effects.     

Developmental changes in visual scanning of face and nonface patterns by infants

The eye movements of infants, aged 4–5, 7–8, and 10–11 weeks, were recorded while they viewed either a representation of a face or a nonface stimulus. Presentation of the visual stimulus was paired with the presentation of an auditory stimulus (either voice or tone) or silence. Attention to the visual stimulus was greater for the older two groups than for the youngest group. The effect of the addition of sound was to increase attention to the visual stimulus. In general, the face was looked at more than the nonface stimulus. The difference in visual attention between the face and the nonface stimulus did not appear to be based solely on the physical characteristics of the stimuli. A sharp increase in the amount of looking at the eyes of the face stimulus at 7–8 weeks of age seemed to be related to a developing appreciation of the meaning of the face as a pattern.     

Memory span and short-term memory capacity: A developmental study

A memory span task involving series conditions comprised of several different types of material was administered to children from three grade levels (7–12 years of age). As expected, age differences were strongly affected by type of material, with two conditions (consonant letters, words) intended to restrict opportunities for chunking yielding age differences that were negligible, and one condition (consonant-vowel letters) constructed to maximize sequential probability yielding age differences that were large. This finding renders less plausible the popular notion that capacity increases with age, and suggests that age differences in memory span reflect chunking processes. Additional findings, which indicate that age differences in memory span are affected by method of presentation and stage of practice, suggest that these variables should be considered in studies aimed at estimating children's memory capacity.     

Semantic organization in the young child: Evidence for the development of semantic feature systems

In two experiments, 5-, 7-, 9-, and 11-year-old children and college students were presented on each trial with a sentence followed by a probe word. Their task was to indicate whether the probe was in the sentence or not. Of primary interest were the false recognitions and the correct latencies that occurred when the probe word was a synonym or antonym of one of the words in the sentence (Experiment I) or when the probe was a subordinate, superordinate, part, or whole (Experiment II). The younger children were more affected by synonymy than antonymy, although the older children and adults were not. At all ages, the categorical relationships caused more recognition confusion than the partwhole relationships. Subjects were more affected when the probe was a superordinate than when it was a subordinate, and somewhat more affected when the probe was the whole than when it was the part. These results suggest that children as young as 5 years of age have well-organized conceptual systems based on shared meaning components.     

The effect of training procedures on the overlearning reversal effect in young children

The performance of 80 preschool children on a reversal problem was studied as a function of amount of training and type of training procedure used during acquisition and reversal. In the extinction phase of reversal learning, subjects given a correction procedure during the reversal problem made fewer perseverative errors than subjects given noncorrection. In the reversal midplateau phase of reversal learning, overtraining facilitated reversal learning for subjects receiving noncorrection during the acquistion problem, but not for subjects receiving correction. A shift in training procedure between acquisition and reversal increased the number of subjects who reached criterion immediately after perseveration. Since these results are difficult to explain in terms of traditional learning theories, an alternative response-switching strategy explanation was proposed.     

Recognition memory for objects in very young children: The effect of shape and label similarity on preference for novel stimuli

In two studies, 88 children 12 to 38 months of age were briefly shown 24 common objects on familiarization trials. On subsequent test trials, these objects reappeared paired with novel objects. On one-third of the test trials pairs were similar in shape, on another third of the test trials pairs shared a common label, and on the remaining test trials pairs were unrelated. Looking times for each of the two objects on test trials were measured. All but the youngest age group showed significantly longer looking times for novel than for familiar objects for all three kinds of test pairs. However, for 19- to 31-month-olds preference for novel stimuli in the common Label Condition, although significant, was less than preference for novel stimuli when shape was similar or when unrelated stimuli were paired. Recognition in the oldest group was unaffected by condition. The results suggest a developmental period during which label or conceptual similarity has a special significance for recognition, and are discussed within theoretical frameworks concerning the very young child's developing semantic and categorization skills.