“P300” and memory: Individual differences in the von Restorff effect

Event-related brain potentials (ERPs) were elicited by words in a free recall paradigm that included a novel item. The P300 component of the ERP is elicited by novel, task-relevant events, and we tested the hypothesis that P300 is a manifestation of the cognitive processing invoked during “context updating.” If the degree to which current representations in working memory need revision is related to P300 amplitude, then the P300 elicited by a given item should be related to the ability to recall that item on a subsequent test. Forty lists were presented to 12 subjects in each of two sessions. The lists were 15 words long, and 1 word, in position 6 through 10, was “isolated” by changing its size. Most subjects recalled these isolated words more often than other words in the same positions (von Restorff effect), and these words also elicited larger P300s than other words. Analysis of variance on the component scores from a principal components analysis revealed that words recalled had a larger amplitude P300 (on initial presentation) than words not recalled. Striking individual differences emerged, and there were strong relationships between the von Restorff effect, overall recall performance, mnemonic strategies, and the association between components of the ERP and recall performance. The overall recall performance of subjects who reported simple (rote) mnemonic strategies was low, but they showed a high von Restorff effect. For these subjects the amplitude of the P300 elicited by words during initial presentation predicted later recall. In contrast, subjects who reported complex mnemonic strategies remembered a high percentage of words and did not show a von Restorff effect. For these subjects P300 did not predict later recall, although a later “slow wave” component of the ERP did. The initial response to isolated items was the same for all subjects (a large P300), and all subjects recognized the isolates faster than other words in a recognition test given at the end of each session. The subjects in whom P300 did not predict recall reported mnemonic strategies that involved organizing the material. These strategies continue long after the time period reflected by P300 (600 msec). Because they were so effective they may have overshadowed the relationship between P300 and recall, which is based on the initial encoding of an event. Our interpretations were further confirmed and clarified from data obtained in a final grand recall and in the recognition test.     

Interruption of phonological coding in conduction aphasia

A case study of conduction aphasia, investigating single word repetition, phonological coding, and short-term memory, is reported. Evidence from intact adults suggests that repetition can occur through either a lexical route or a direct auditory-articulatory link. For this conduction aphasic, E.A., the direct link was impaired, although the lexical route could be used to produce accurate single word repetition. Several experiments demonstrated a significant impairment in the generation and maintenance of an abstract phonological code. The consequences of a disruption of phonological coding on speech perception and on verbal short-term memory are discussed.     

Student characteristics and motivational and process factors in relation to styles of career development

In this study student background characteristics and certain personological characteristics, including motivations for schooling and types of learning strategies employed, are investigated in relation to affective and cognitive aspects of adolescent career development. A Career Development Inventory, Learning Process Questionnaire, Word Knowledge test and General Information Questionnaire (addressing demographic and career decision-making topics) were administered to national random samples of 14-year-old and grade 11 students. Canonical correlation analyses distinguished at least three styles of career development (possibly four), and associations with student characteristics suggested the motives and strategies that might plausibly enter into the various modes.     

Anticipation of reward omission as a cue for choice behavior

A within-subject partial reinforcement extinction effect was obtained in a conditional discriminative choice task. In choice acquisition, one group had learned a task in which one choice alternative was continuously reinforced (CRF) and the other alternative was partially reinforced (PRF). Most errors in the acquisition phase were the choosing of the CRF lever when the conditional stimulus signaled the PRF lever; in extinction this pattern of choice errors reversed. In extinction, most errors were choosing of the PRF lever when the conditional stimulus signaled the CRF lever. The predictions of frustration theory and sequential theory were compared with the choice data. The results were interpreted as consistent with the anticipatory frustration construct within an associative mediational theory.     

Stutterers' voice initiation times during conditions of novel stimulation

The present experiment examined stutterers' voice initiation times (VITs) during conditions of novel stimulation. The experimenters were interested in determining how VITs varied as a function of pacing and masking. Stutterers were examined in control, pacing, and masking conditions. The results indicated that: (1) stutterers significantly improved their VITs in the pacing condition as compared with the control condition (p = 0.005), (2) stutterers had significantly faster VITs in the pacing condition as compared with the masking condition (p = 0.005), and (3) stutterers improved VITs in the masking condition as compared with the control condition (p = 0.075). These results are discussed in terms of the facilatory nature of novel stimulation in modifying speech-system functioning.     

Existential measurement: A factor analytic study of some current psychometric instruments

The foray of quantification research into the arena of existentialism and ontology has given rise to several psychometric instruments pertinent to the area. Both exploratory and Confirmatory principal-factor analyses were used to study the relationships among 16 existential scales currently in use in the research literature. Participants were 133 individuals comprised of 74 females and 59 males with a median age of approximately 30.5 years. Approximately one half of the sample was in attendance at the University of Regina and Saskatchewan during the 1976–1977 fall term, while the remainder was drawn from the respective communities. Confirmatory factor analysis supported both the prediction of substantial condensation of existential scales and the presence of an avoidance of ontological confrontation factor. Exploratory factor analysis provided some support of the theory that the avoidance of existential confrontation is a central function of neurosis. Extracted factors were interpreted and examined with respect to implications for existential-ontological theory and research.     

The composite measure of the defense mechanism inventory

A reanalysis of previously published data suggests that the Defense Mechanism Inventory can be utilized to yield a composite measure of reaction to frustration by contrasting linearly the defenses of Turning-against-object and Projection against those of Principalization and Reversal-of-affect. Factor-analytic and correlational data support the exclusion of Turning-against-self from the composite measure. Studies of content validity are presented for the combination of the four defenses into one dimension. Patterns of interitem reliability are charted for the five defenses and the composite measure for both men and women. Internal consistency data are also presented for the standard scoring as well as for a modified method to explore the feasibility of simplifying and shortening the test-taking procedure.     

The effect of context on the structure of categories

Three experiments examined the effect of context on the representativeness ordering of exemplars of a category. Experiments 1 and 2 employed an online reading time paradigm to examine the effect of context on the time it takes to establish an anaphoric reference between an exemplar and a category term. Experiment 1 demonstrated that context can change the relation between a category term and an exemplar at the time of comprehension. Experiment 2 showed that category terms presented in context generate graded goodness-of-example distributions of exemplars that are different from the distributions generated in the absence of explicit context. These distributions cannot be derived by assuming that the exemplar most strongly suggested by the context serves as the category representation. Experiment 3 employed a membership verification paradigm. Response time was found to be a function of degree of relatedness to the contextdependent category representation. Typicality, as determined in the absence of explicit context, had no effect on decision time. Several models, including some extensions of current semantic memory theories, are developed to account for the results of these experiments.     

Factors affecting choice,satisfaction, and success in the female self-employed

The purpose of this study was to determine variables which predict occupational choice, satisfaction, and success in the self-employment of women. In order to investigate this question, a group of female owners was compared to groups of female managers and secretaries on six variables under consideration: achievement motivation, locus of control, sex-role “masculinity,” and availability of models for ownership—father, mother, and other. There were 47 women in each group.It was found that the six variables, considered simultaneously, discriminated among the three occupational groups. The owners were higher than secretaries in achievement motivation, locus of control internality, and sex-role “masculinity.” However, there were no significant differences between owners and managers on these variables. Owners had more parental models (both fathers and mothers) for ownership than either managers or secretaries. Owners, managers, and secretaries did not differ significantly in the number of nonparental models for ownership. Neither job satisfaction nor success in business ownership were found to be related to the six variables considered simultaneously.