Biomedical subjects

D L Strayer

Publications and source records attributed to D L Strayer.

6 recordsLinked to original sources

PubMed1992

Event related potentials and EEG components in a semantic memory search task.

This study examined the effects of memory search and related processes on both time and frequency domain components of electroencephalographic activity. More specifically, we were interested in the relationship between EEG and event-related potential (ERP) components as a function of memory load and response type. Subjects performed a semantic memory search task in which they matched word probes to category labels. Consistent with previous studies, reaction time increased and accuracy decreased with increasing memory loads. A negative component of the ERP (N400) was found to reflect semantic mismatch: N400s were larger for the nontargets than for the targets. Two ERP components were found to be reciprocally related to memory load. P300 decreased and Negative Slow Wave increased in amplitude with increases in the size of the memory set. These two ERP components were reflected by different components in a Principal Components Analysis. The power in the theta band (5-7 Hz) also increased as a function of memory load and appears to be functionally and topographically related to the Negative Slow Wave in the ERP. It is argued that both measures are jointly determined and reflect the difficulty of the conceptual operations during memory search.

Adult↗

PubMed1991

Task versus component consistency in the development of automatic processing: a psychophysiological assessment.

A study was conducted to examine the role of consistency in the development of automatic processing. Subjects performed a memory search task in which consistent and inconsistent attending and responding were factorially combined. The task was performed with memory set sizes of two and four items. Results indicated that automaticity developed with consistent attending regardless of whether responding was consistent or inconsistent. However, measures of reaction time, P300 latency, and P300 amplitude revealed costs for inconsistent responding that were attributed to both stimulus evaluation and response related processes. The results suggest that total task consistency is not necessary for the development of automatic processing. Instead, it appears that automaticity can develop for consistent task components even when stimulus-response consistency is not maintained across the entire task.

Adolescent↗

PubMed1990

Development and transfer of automatic processing.

Two studies were performed to examine the role of consistency in the development and transfer of automatic processing. Ss performed a rule-based memory search task in which they compared multidimensional probes to 1, 2, or 3 memory set rules. Results indicated that learning occurred in the absence of consistency at lower levels of task description (e.g., mapping of individual task components to responses) as long as higher level consistencies existed in the task (e.g., consistent) mapping of task components to a conceptual framework). However, the asymptotic level of this learning was modulated by the consistency with which conjunctions of task components were mapped to decisions. High positive transfer was obtained despite replacement of the exemplars of the memory set rules, suggesting that learning was not specific to the items encountered during training. On the other hand, the magnitude of positive transfer was reduced when the rules were replaced, suggesting that most of the learning took place at the level of specific rules. Some evidence was also obtained for more general process-based learning. Results are discussed in terms of their implications for models of learning and transfer.

Adolescent↗

PubMed1990

An analysis of memory-based theories of automaticity.

Memory-based theories of automaticity predict that performance in a memory search task which is automatic will not require a representation of the memory set in working memory. The information contained in working memory was manipulated by inserting an interference task between the presentation of a memory set and a probe stimulus in a memory search task. The interference task prevented rehearsal, necessitating the retrieval of the memory set from long-term memory in variably mapped (VM) conditions. Performance in consistently mapped (CM) conditions provided strong support for memory-based theories of automaticity. With CM practice, both the effects of memory load and the effect of the interference task were eliminated. Furthermore, there was a temporal coupling in the reduction of these two effects with consistent practice. Monte Carlo simulations of memory-based automaticity predict such a temporal coupling. Automaticity is viewed as a continuum reflecting the relative contribution of the direct memory access of past solutions from long-term memory on performance.

Adolescent↗

PubMed1988

Assessing the development of automatic processing: an application of dual-task and event-related brain potential methodologies.

Previous research has found that properties of automatic processing do not always co-occur, suggesting that the acquisition rates may differ. The present study investigated the acquisition rate of several of these properties by employing additive factors logic, dual task methodology, and event-related brain potentials. Seven subjects participated in a ten session experiment in which they performed two tasks, a visual/memory search task and a pursuit step tracking task, both together and separately. RT and P300 latency measures indicated that parallel processing of the display was achieved early in training in the consistent mapping condition. This processing was unaffected by dual task demands. An analysis of RT/P300 ratios suggests that another form of perceptual efficiency was achieved later in practice in both the varied and consistently mapped search tasks. This effect was larger in the consistent mapping condition. Reductions in the slope of the memory set function occurred significantly earlier for P300 latency than for RT, suggesting that the stimulus evaluation processes became automated more rapidly than the response selection components of memory search. Consistent with an analysis of the processing demands of the two tasks, the introduction of the tracking task and an increase in tracking difficulty produced equivalent interference during consistent and varied mapping conditions. Results are discussed in terms of models of skill, skill acquisition and component task automaticity.

Adult↗

PubMed1987

Adult age differences in the speed and capacity of information processing: 2. An electrophysiological approach.

A total of 60 subjects performed different variants of the Sternberg memory search task in an experiment designed to evaluate aging differences in the speed of the human information-processing system. The present study examined the nature of the age-related slowing using convergent methodologies of Sternberg's additive factors logic, the speed-accuracy trade-off, and the P300 component of the event-related brain potential. These methodologies revealed that a substantial component of slowing was manifest in perceptual encoding, response criterion adjustment, and response execution, with a lesser component related to memory search speed.

Adult↗