“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.     

The Boston Naming Test: Norm data and cue utilization in a sample of normal 6- and 7-year-old children

The object-naming abilities of 83 normal children were examined using the Boston Naming Test developed by E. Kaplan, H. Goodglass, and S. Weintraub (1976, The Boston Naming Test (experimental edition), unpublished test, Veterans Hospital, Boston, Massachusetts). There is currently a lack of available norms for this instrument, especially for populations of younger children. Cue utilization in this sample is explored and attention is focused upon possible gender differences in naming performance and cue strategies. Seven summary scores derived from the test are presented in this report. Results indicate that the Boston Naming Test can discriminate within a normal population sample of young children and provides a relatively normal distribution for six of seven derived scores. Boys were found to have a significantly greater number of items correctly named but no gender differences in cue utilization were evident. A major proportion of the children in this sample of 6- and 7-year-olds used phonological cues almost exclusively, rather than semantic cues also provided. Cue use was not related to age or spontaneously given responses, and none of the children were found to be highly proficient at using both types of cues.     

Altered patterns of word associations in dementia and aphasia

The word associations of 38 demented, 17 aphasic, and 22 normal subjects were studied. Both normal and brain-injured subjects appear to make judgments about the grammatical class of the word stimulus. Certain stimulus words (especially nouns and adjectives) elicit paradigmatic responses whereas other words (especially verbs and adverbs) elicit syntagmatic responses. The mechanism producing syntagmatic responses seems relatively resistant to deterioration in dementia or aphasia. However, in dementia the mechanism that generates paradigmatic responses becomes progressively less efficient (possibly due to a loss of semantic markers) and consequently more random (idiosyncratic) responses emerge. Perseverative responses, inhibited in normal subjects, are more prevalent in dementia. Anomic aphasics show a pattern of word associations similar to that of subjects with mild dementia. Broca's aphasics, while making fewer paradigmatic associations than normals, retain enough self-monitoring mechanisms so that few idiosyncratic and perseverative responses are made while more null responses occur. Wernicke's aphasics show a marked shift away from a paradigmatic word association strategy, possibly due to an inability to access semantic markers or a true loss of these markers. Metalinguistic deficits (i.e., a failure to adopt an appropriate strategy) may also contribute to this shift away from paradigmatic associations. Furthermore, a disruption of self-monitoring mechanisms in Wernicke's aphasia leads to an increase in perseverative and idiosyncratic responses.     

A model of fixed activation time scheduling

A model for the fixed activation time scheduling of events is presented. Activation time is defined as the time needed for an event to regain dominance in the stream of events measured from the point in time at which it lost dominance. The fixed activation time scheduling rule states that some event must be ongoing at all times, that an ongoing event will continue until interrupted by another event, that every event has a predetermined activation time and that fulfilling the activation time requirement is the necessary and sufficient condition for an event to interrupt an ongoing event. The last condition sets this rule apart from those employed in quequeing theory since it does not allow events to be completed or queues to form. Derivations from the model concerning the dynamic organization of the stream of events, written in terms of the frequency and duration of events and the transitions between pairs of events, are given. Special attention is paid to issues that arise in deciding on the coding of events. It is suggested that the fixed activation time scheduling rule will apply to a wide variety of settings, environmental and behavioral, and this is illustrated by a detailed application of the model to observations on the stream of free behavior.     

The cognitive representation of persons and groups and its effect on recall and recognition memory

A conceptualization of the manner in which trait and behavioral information is organized in memory is proposed and applied in predicting both the recall and recognition of information about persons and groups. Three information presentation conditions were considered: (1) Subjects are told to form an impression of a target (person or group) on the basis of the target's behaviors, and are given a trait-based concept of what the target is like before learning about these behaviors. (2) Subjects are told to form an impression of the target, but a general traitbased concept of the target is not induced until after they learn about the target's behaviors. (3) Subjects receive information about the target's behaviors with instructions to remember the information, and only subsequently are told to form an impression and are given more general information about the target's traits. The proposed model accounted for between-condition differences in both the recall and recognition of behaviors that were consistent and inconsistent with a general trait-based concept of the target, and for contingencies of these differences on whether the target was a single person or a group.     

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.     

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.