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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↗

PubMed1990

Phonological and motoric demands in handwriting: evidence for discrete transmission of information.

In an experiment with handwriting tasks effects of phonological and motoric task factors upon reaction time and movement time were measured to test implications of a discrete information processing account of the task. The model is built up of serially organized stages, each of which monitors one specific type of operation, necessary to generate a message. The serial structure of the model is defined as the limitation that higher levels of the model provide their output to the next lower processor in the hierarchy, and receive their input from the next higher stage. The parallel character of the model is exemplified through the assumption that all processors are active at the same time and concurrently with the real time production of writing movements. The study adds evidence that a serial architecture of processors can be compatible with the parallel processing of a message as long as more abstract operations are prepared more in advance to real-time movements than operations lower in the hierarchy. In the experiment the prediction was tested that the time course of the manifestation of phonological and motoric task demands reflects the discrete and serial structure of the model.

Adult↗

PubMed1989

Human brainstem auditory evoked potentials fail to provide evidence of efferent modulation of auditory input during attentional tasks.

Efferent modulation of auditory input at the level of the brainstem during attention-demanding tasks has been described in animal studies. Attempts to demonstrate these effects in humans have produced conflicting results, however. These studies are reviewed with particular reference to those animal experiments that have demonstrated peripheral effects. The human experiments have used a number of attentional conditions which have not been related either to each other or to the successful animal work. Two of the most important conditions in these studies--the use of an intermodal attention task and the manipulation of attentional states--have been examined rarely or not at all in the human research. Two experiments were conducted to investigate the possibility of attention-related effects on the human brainstem auditory evoked potential. These experiments were designed to examine experimental conditions common to both successful and unsuccessful attempts to demonstrate attention-driven efferent modulation at the periphery in humans. Also examined was the gradation of attention effects on efferent modulation demonstrated in animals but never studied in humans. No significant changes in either the latency or the amplitude of the brainstem auditory evoked potential were found in any of the attention-demanding conditions. Results are discussed in terms of psychophysiological theories of attention. Also, the interpretation of the most recent animal work is questioned.

Adolescent↗

PubMed1989

Contextual information and temporal terms.

We report an experiment designed to identify how contextual information can influence children's performance on an experimental task involving temporal terms. Crain (1982) reported improved performance on a comprehension task when subjects were provided with contextual information, and he suggested that the improvement was due to satisfaction of presuppositions. However, this contextual information might have served to simplify task demands by providing prior information concerning an important aspect of the task. The present study distinguishes these factors by incorporating contextual information into the subordinate clause of the test sentences in a comprehension experiment (to satisfy presupposions) or into the main clause (to provide comparable prior information without satisfying presuppositions). We conclude that contextual information results in a significant improvement only when such information can be used to satisfy presuppositions.

Child Language↗

PubMed1989

Effects of age and a divided attention task presented during encoding and retrieval on memory.

The present studies were designed to examine age differences in memory when attention was divided during encoding, retrieval, or at both times. In Experiment 1, Ss studied categorized words while performing a number-monitoring task during encoding, retrieval, or at both times. Older Ss' free recall and clustering performance declined more than that of young Ss when attention was divided at encoding, but there was no similar age interaction when divided attention occurred at retrieval. In Experiment 2, the task demands at retrieval were increased by using a fast-paced, cued-recall task. The results remained unchanged from Experiment 1. Again, an age interaction occurred with divided attention at encoding but not at retrieval. These results were unexpected, given the emphasis in the memory-aging literature on increased difficulty of retrieval by older adults. The findings pose difficulties for limited processing resource views of age differences in memory.

Adult↗

PubMed1979

Are retarded children more distractible? Observational analysis of retarded and nonretarded children's classroom behavior.

Retarded children are frequently characterized as more distractible and/or more outerdirected than are nonretarded children. In this study behavior thought to reflect these processes was described and the relationship of this kind of behavior to task demands was examined. Retarded and nonretarded children were observed while they worked on academic classroom tasks; retarded children were also observed while they worked on nonacademic tasks. Results indicated that retarded children were less attentive than were nonretarded children during academic periods: They spent less time on task, more time out of their seats, and more time "looking busy" but not working. Little support was found for the notion that retarded children are more outerdirected than are nonretarded children. Retarded children responded differently in nonacademic and academic situations, suggesting that behavior reflecting attention is task-related. Results were discussed in terms of previous conceptualizations of retarded persons' attention processes. Implications for future research and for educational practice were also discussed.

Attention↗

PubMed1992

Reasoning with conditionals containing negated constituents.

Three experiments investigated matching bias in conditional reasoning tasks. Matching bias occurs when Ss ignore negations and match named items. Experiment 1 used an abstract and a thematic version of Evans's (1972) construction task. Results showed that matching may be due to an interaction between task demands and constructing contrast classes when interpreting negations. Experiment 2, which used Wason's (1968) selection task, introduced a manipulation to ease contrast-class construction. Confirmation plus falsification dominated over matching. Experiment 3 introduced two other manipulations to aid contrast-class construction with abstract material. Confirmation was facilitated, matching was suppressed, and falsification remained unchanged. These results suggest that matching occurs only when insufficient or ambiguous information prevents the intended interpretation of negations.

Adult↗

PubMed1990

Interaction of attentional and motor control processes in handwriting.

The interaction between attentional capacity, motor control processes, and strategic adaptations to changing task demands was investigated in handwriting, a continuous (rather than discrete) skilled performance. Twenty-four subjects completed 12 two-minute handwriting samples under instructions stressing speeded handwriting, normal handwriting, or highly legible handwriting. For half of the writing samples, a concurrent auditory monitoring task was imposed. Subjects copied either familiar (English) or unfamiliar (Latin) passages. Writing speed, legibility ratings, errors in writing and in the secondary auditory task, and a derived measure of the average number of characters held in short-term memory during each sample ("planning unit size") were the dependent variables. The results indicated that the ability to adapt to instructions stressing speed or legibility was substantially constrained by the concurrent listening task and by text familiarity. Interactions between instructions, task concurrence, and text familiarity in the legibility ratings, combined with further analyses of planning unit size, indicated that information throughput from temporary storage mechanisms to motor processes mediated the loss of flexibility effect. Overall, the results suggest that strategic adaptations of a skilled performance to changing task circumstances are sensitive to concurrent attentional demands and that departures from "normal" or "modal" performance require attention.

Attention↗

PubMed1991

The influence of children's facial maturity on parental expectations and punishments.

It was hypothesized that the perception of maturefaced children as more able to follow complicated instructions, more likely to know right from wrong, more shrewd, and physically stronger than their babyfaced peers would lead parents to assign more demanding tasks to these children and to judge their misbehavior more harshly. Study 1 revealed that parents allocated more cognitively demanding, but not more physically demanding, chores to maturefaced 11 year old depicted in photographs than to babyfaced children of the same age and attractiveness. Study 2 revealed that parents perceived the misbehaviors of maturefaced 4- and 11-year-old children as more intentional than those of their babyfaced peers, an effect that was significant only when parents judged children of the opposite sex. Study 2 further revealed that, with perceived intentionality held constant, a babyface mitigated the severity of punishment recommended for relatively serious infractions by preschoolers, while increasing it for older children. The latter finding was discussed in light of other evidence that people react negatively to the disconfirmation of their benign expectations regarding babyfaced individuals, and that parents perceived the misbehaviors as more unexpected for 11 year olds than 4 year olds.

Achievement↗

PubMed1975

Diurnal variation in logical reasoning.

Subjects performed two tests of logical reasoning at each of six different times of day. In terms of speed, preformance on both tests was found to improve markedly from 08.00 to 14.00 and then to fall off fairly rapidly. Accuracy was found to decrease fairly linearly over the day. The results are interpreted as indicating that the different functions relating performance efficiency to time of day found by previous workers are due to differences in task demands rather than to individual differences. It is suggested that the larger the short-term memory component of a task the earlier in the day performance peaks.

Achievement↗

PubMedDate not supplied

A comparative study of the effects of carbon monoxide and methylene chloride on human performance.

The purpose of this investigation was to determine whether similar carboxyhemoglobin (COHb) values obtained from inhaling carbon monoxide or methylene chloride have the same behavioral effects. The effects were assessed by the performance of 12 humans on a visual-manual, dual-task, and an auditory vigilance task. The results indicated that both substances in concentrations sufficient to produce 5-percent COHb significantly impaired human performance under difficult or demanding task conditions. The conclusion was that carbon monoxide, the main metabolite of methylene chloride, was responsible for the observed performance decrements.

Adolescent↗

PubMed1992

Development of physical fitness standards for Canadian Armed Forces younger personnel.

The purpose of this study was to develop minimum physical fitness standards based on common task criteria for personnel younger than 35 years of age in the Canadian Armed Forces. A random sample of 66 men and 144 women performed the Exercise Prescription (EXPRES) test and five physically demanding tasks that simulated common military tasks. Common cutting scores were selected as the point at which 75% of the total weighted sample passed each task. Since there were significant differences between the sexes in task performance and technique execution, the groups were analyzed separately. Results indicated a range in variance of 14 to 48% between military task performance and physical fitness test score, thus suggesting that fitness measures are a poor predictor of task performance. Because of the low variance observed the passing group of each task was treated as a representative sample of subjects whose fitness profiles were indicative of those able to meet task criteria. The 5th percentile fitness scores of the passing group were proposed as the minimum fitness standard. These conditions resulted in fitness standards that were physically more demanding for women than for men.

Adult↗

PubMedDate not supplied

[Experimental model of heuristic decision making in experiments on rats for pharmacologic screening].

In experiments on 399 rats the authors developed a method permitting the evaluation of the rate and probability of solving the task demanding from the experimental animals to survive after immersion in cold water. Each animal was exposed to stress only once in life. The task was solved by the animals with the probability rate of approximately 80-100% within 2 min. The pharmacological agents with the depriming effects (morphine, aminazine, sodium oxybutyrate, phenazepam) decreased the aim-oriented behavioral reactions of experimental animals. Caffeine (5-10 mg/kg) decreased the reaction time necessary for solving the task and phenazepam (5 mg/kg) blocked the decision made by the exposed rats to eliminate the stress situation. Nootropil and strychnine exerted no effects on the probability and quickness of the exposed rats to solve the stressful task.

Animals↗

PubMed1990

Manual asymmetries during verbal and spatial block design construction.

To examine the effects of cognitive task demands on manual asymmetry, 40 male and 40 female college students were asked to simultaneously construct two replicas of a verbal or spatial block design task, one with each hand. In addition, a verbal and spatial competition task also was performed concurrently with each of the two primary tasks in a dual task paradigm. The spatial primary task elicited increased left-hand use relative to baseline performance, but only in males. An increase in right-hand use was observed during performance of the verbal primary task, again primarily among males. The effects of concurrent cognitive tasks on hand utilization were observed only in subjects performing the verbal primary task, and only when the concurrent task was verbal in nature. Implications for theories of functional cerebral lateralization are discussed.

Adult↗

PubMedDate not supplied

Historical factors in the development of ETOH-conditioned place preference.

Three groups of male Sprague-Dawley rats were conditioned with ethanol (ETOH) and water in a Conditioned Place Preference task. To assess the contribution of prior drug/behavioral history on the relative hedonic valence of ETOH, the three groups differed in the task demands and degree of prior ETOH exposure. One group was trained to self-administer 20% w/v ETOH in a home-cage self-administration task using a "Samson sucrose-fading" procedure prior to place conditioning trials (Group SA/CPP). A second group was initially trained in a two-choice ETOH-Saline drug discrimination (DD) task and subsequently conditioned in the place preference paradigm (Group DD/CPP). The third group of rats had no history of drug exposure and were experimentally naive prior to the place learning task (Group NH/CPP). Group SA/CPP developed a significant conditioned place preference; Group DD/CPP failed to demonstrate either a preference or aversion, whereas the Group NH/CPP demonstrated a significant place aversion. Data suggest that both present and past contingencies contribute to the algebraic summation of ETOH's hedonic valences.

Animals↗

PubMed1992

Cigarette smoking and cognitive performance.

While some investigations into the relationship between smoking and cognitive performance have reported that smoking facilitates performance, other research has come to the opposite conclusion. A review of the literature suggests that this variance in results may be due to differences among studies in design (comparing smokers only with deprived smokers rather than with non-smokers) and also to differences in task demands. Therefore, performance of smokers having just smoked, matched smokers deprived for a brief period, and also non-smokers was contrasted on a series of tasks which ranged from repetitive and perceptually-bound tasks to complex, dynamic tasks dependent upon long-term memory. It was found that while cigarette smoking had no negative effect upon performance for simple perceptual tasks, smoking was found to exert measurable negative effects upon performance for more complex information processing tasks.

Adult↗

PubMed1991

Auditory attention switching: a developmental study.

The developmental course of the ability to rapidly allocate attention was studied using a dichotic listening task with 8-year old, 11-year old and college age subjects. In this task, subjects were instructed to listen to one ear for predescribed targets and then were later signaled (on some trials) to switch their attention to the other ear. Reorientation was assessed by comparing the pattern of subjects' omission and intrusion errors on trials following a command to switch ears with the pattern of errors on no-switch trials. Older subjects were better able to reallocate their attention in accordance with task demands, with the greatest gains in performance occurring between ages 8 and 11. This developmental change appears to be generally continuous and quantitative in nature. Since successful performance of this task requires flexibility in subjects' ability to control their focus of attention, these results support the hypothesis that the basis of the developmental improvement in the ability to ignore irrelevant information is linked to the ability to use active attentional strategies.

Adolescent↗

PubMed1979

The effects of EMG feedback training during problem solving: a case study.

The present case study investigated the effects of competing task demands on biofeedback training to reduce frontalis muscle tension. Baseline levels of frontalis muscle tension were recorded for relaxation and problem solving. The subject was trained to decrease muscle tension with biofeedback for the problem-solving task alone. The results indicated that EMG training during problem-solving was successfully accomplished. Frontalis muscle tension during relaxation baseline did not change as a result of reductions in muscle tension during problem-solving feedback training. This suggests that the decrease of muscle tension cannot be attributed to reductions in overall muscle tension levels. Instead, training was specific to the problem-solving feedback phases. Additionally, it was found that accuracy in problem-solving did not decline as a result of simultaneous feedback training. Thus EMG biofeedback training can be accomplished and exercised without disruption of ongoing mental activity.

Adult↗