Doubling the rate of signal presentation in a vigilance task during sleep deprivation.

An experiment was conducted to test the effect of doubling the amount of work required of Ss after loss of sleep. Ss were required to detect defined sequences of 3 digits ("signals") within an apparently random series. Digits were presented continuously for 30 min. either at 1 per sec. (slow) or 2 per sec. (fast). The slow condition contained 20 signals; the fast condition 40. Slow and fast groups were tested on 3 successive days of a 60-hr. vigil and 2 similar groups under control conditions. The results showed that loss of sleep affects performance under fast less than under slow. These and other results suggested that stimulation reduces the effect of sleepiness on performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of task complexity and practice on performance after loss of sleep.

An experiment was conducted to assess the effects of degrees of task complexity and practice on performance after loss of sleep. The Ss were automatically presented every 7 sec. for 23 min., with cards containing 6 symbols. A symbol had to be chosen on the basis of certain rules. Some cards required 1 rule, some 2, some 3, and some 4. Group 1 was practiced after normal sleep and tested after 22 and 46 hr. without sleep. Group 2 was tested without sleep and without previous practice. Group 3 was practiced and tested after normal sleep. Loss of sleep had a greater effect after practice, but no clear differences emerged between the different levels of task complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of leadership in a simulated industrial task.

Ss high and low in dominance were selected with the CPI Dominance (Do) scale and confronted with a simulated industrial task which could be solved best by 1 person assuming a leader role and the other following his instructions. When the instructions emphasized the task, the High Do Ss did not assume the leader role significantly more often than the Low Do Ss. When leadership was emphasized, however, the High Do Ss assumed the leader role in 90% of the pairs. It is concluded that the CPI Do scale has predictive validity when leadership is made salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One night of total sleep deprivation impairs implicit learning in the serial reaction task, but not the behavioral expression of knowledge.

Implicit sequence learning in the serial reaction task suffers from total sleep deprivation. The authors compared implicit-learning scores in a sleep-deprivation (SD) group (n = 12) and a control group (n = 6). Both groups were tested immediately after learning a 1st sequence; a delayed test was conducted on the next day (after a night without sleep in the SD group). Immediately after the delayed test a 2nd sequence was learned, followed by an immediate test and a delayed test toward the end of the experiment. In the SD group implicit-learning scores were reduced in both tests of the 2nd sequence, but in neither test of the 1st sequence. Thus, 1 night of total sleep deprivation impairs the acquisition of implicit sequence knowledge, but not its behavioral expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflict and repression during sleep deprivation.

"A series of three TAT cards representing a continuum of low, medium, and high sleep suggestions was selected on the basis of rankings by 10 psychologists and 10 lay people. These three cards were administered… to 24 experimental Ss after about 86 hours of sleep deprivation, as well as to 24 control subjects… . [On these TAT cards] the sleep-deprived group gave fewer sleep themes than did the control group… . The results… were interpreted as indicating that the subjects were avoiding thoughts or verbal responses which might arouse overpowering sleepiness… . An analysis of these phenomena in terms of the Dollard-Miller theory of repression was made." 23 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interhemispheric asymmetry of human sleep EEG in response to selective slow-wave sleep deprivation.

Recent evidence suggests that the human sleep electroencephalogram (EEG) shows regional differences over both the sagittal and coronal planes. In the present study, in a group of 10 right-handers, the authors investigated the presence of hemispheric asymmetries in the homeostatic regulation of human sleep EEG power during and after selective slow-wave sleep (SWS) deprivation. The SWS deprivation was slightly more effective over the right hemisphere, but the left hemisphere showed a markedly larger increase of EEG power in the 1.00-24.75 Hz range during recovery-night non-REM sleep, and a larger increase of EEG power during both deprivation-night and recovery-night REM sleep. These results support the greater need for sleep recuperative processes of the left hemisphere, suggesting that local sleep regulation processes may also act during REM sleep. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional task aptitude and performance anxiety.

Anxious responding (trait, state, and test anxiety) has a negative impact on overt performance. Researchers have used a unidimensional method of assessing anxiety and performance, although a more informative approach would involve a comprehensive assessment battery and multiple performance tasks. Incorporating this strategy, the authors measured the impact of anxiety on 4 attentional processing tasks. Results revealed that "types" of anxiety symptoms were differentially related to attentional task performance; test anxiety accounted for the most variance in predicting performance on the Wechsler Adult Intelligence Scale-Third Edition (D. Wechsler, 1997) letter-number sequencing and digit-span subtests, trait anxiety and fear of negative evaluation were more significant in predicting Stroop performance, and math anxiety accounted for the largest variance toward understanding Paced Auditory Serial Addition Task (C. W. Lejuez, C. W. Kahler, & R. A. Brown, 2003) scores. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A meta-analysis of the impact of short-term sleep deprivation on cognitive variables.

A substantial amount of research has been conducted in an effort to understand the impact of short-term (     

Group performance in a cognitive task.

On a cross-word puzzle task performed by 60 pairs of male Ss, correlations between group performance and performance of the individuals (independently determined) were calculated. 82% of the true group performance variance on the task could be predicted from the individual performance scores. "It is suggested that the nature of the task is important in studies of group performance, and that the existence of 'group' phenomena should be empirically demonstrated rather than assumed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivation in a task situation as a function of ability and control over the task.

102 psychology students participated in the task of constructing and validating an "academic aptitude test." Training (level of ability) and amount of control over the task were manipulated in a 2 X 2 factorial design. For untrained Ss, performance was positively related to control. The performance of trained Ss was negatively related to control, contrary to prediction. This reversal was tentatively attributed to unintended "side effects" of the training manipulation. As predicted, expected success was positively related to training, perceived ability, and perceived control. A manipulation of success and failure in the task led to results consistent with predictions: Success produced incerases in satisfaction and perceived ability, while failure led to decreases in perceived ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of 42 hr of total sleep deprivation on component processes of verbal working memory.

The current investigation examined changes in working memory (WM) component processes following total sleep deprivation (TSD) in a sample of healthy young persons. Forty subjects were administered a verbal form of a continuous recognition test (CRT) before and after 42 hr of TSD. Parameters of a computational model of the CRT reflecting attention, WM span, and rate of episodic memory encoding were estimated for each individual. Subjects made more errors on the test following sleep deprivation. Analysis of model parameters revealed statistically independent declines in both the attention and WM span parameters, with a larger effect observed for the decline in WM span. Examination of individual profiles suggested that the effects of TSD on verbal WM component processes vary from person to person. Declines in global verbal WM functioning appear to be primarily driven by reduced WM span and attention; however, these effects may be individual-specific. Further applications of the computational model for examining WM component processes with sleep deprivation and other clinical populations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early social deprivation induces disturbed social communication and violent aggression in adulthood.

Disturbed social relations during childhood (e.g., social neglect) often lead to aggression-related psychopathologies in adulthood. Social isolation also increased aggressiveness in laboratory animals. Here the authors show in rats, that social isolation from weaning not only increases the level of aggressiveness, but results in abnormal attack patterns and deficits in social communication. In socially deprived rats, the share of attacks aimed at vulnerable body parts of opponents (head, throat, and belly) dramatically increased and the attack/threat ratio was shifted toward attacks, suggesting a decrease in intention signaling. Moreover, a Multiple Regression Analysis showed that the nonassociation of attacks with offensive threats predicted the occurrence of vulnerable attacks with 81.1% accuracy. The authors suggest that the social deprivation-induced abnormal aggression models the aggression-related problems resulting from early social neglect in humans, and studies on its brain mechanisms may increase our understanding of the mechanisms underlying psychopathologies resulting from early social problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of immediately preceding task brightness on visual performance.

To determine how visual performance at low photopic brightness levels is affected by the brightness of an immediately preceding visual task, Ss were required to read photographs of banks of instrument dials (a near-vision task) and banks of Landolt rings (a far-vision task) after adaptation to the brightness level of the first task, under speed and accuracy instructions. The Ss performed both the near and far tasks. Within the brightness ranges used, performance was related to the brightness of the task but not to the brightness of the immediately preceding task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of work-group structure and certain task variables on group performance.

This investigation explored how team performance varies as a function of information processing demands and how the information-handling capacity of teams depends upon the requirements for internal transmission of information imposed by a communication structure. 3-man groups performed a simple "team" task under 2 different work structures, differing in the extent to which they required the transmission of information. "… the most difficult structure was that in which a larger proportion of information had to be relayed… from several different sources… . Errors for both structure conditions significantly increased when the rate of change of instrument readings increased." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Schizophrenic performance in a word-communication task.

Speaker and listener skills in schizophrenic and in normal Ss were studied using a communication task in which the speaker provides clue words to distinguish referent from nonreferent stimuli, and the listener chooses the speaker's referent from each stimulus array on the basis of the speaker's clue words. 4 groups of 18 speaker-listener pairs were used: schizophrenic speakers-schizophrenic listeners; schizophrenic speakers-normal listeners; normal speakers-schizophrenic listeners; normal speakers-normal listeners. Analysis of accuracy scores (proportion correct referent choices) showed that schizophrenic speakers were inferior to normals (p     

Variability of performance in a vigilance task.

An experiment was conducted to determine the effect of signal pattern and frequency on the variability of S's performance in a vigilance task. Ss were 12 male college students who watched 3 dials during 3 consecutive 27-min. periods. Real signals occurred alone in 1 period while 2 different patterns of dummy signals were added in the other 2 periods. It was found that dummy signals which occurred at semiregular intervals were more effective in reducing S's variability than those which occurred at nonregular intervals. It was also found that variability increased with time. It is concluded that use of a semiregular pattern of dummy signals would be one way of improving performance on a vigilance task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leader's contribution to task performance in cohesive and uncohesive groups.

Army tank crews, B-29 bomber crews, antiaircraft artillery crews, and creative discussion groups provided data which were analyzed to determine the relationship between the leader's intelligence and group performance. Each sample was divided into cohesive and uncohesive groups, and the correlation between the leader's intelligence and group performance was computed. The results indicated consistently that the leader's intelligence predicts group performance in cohesive groups, but not in uncohesive groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of anxiety and threat on the solution of a difficult task.

"Two variables were manipulated in this research, anxiety and experimental instructions administered prior to the subjects' performance on a series of anagrams high in difficulty level. Three measures of anxiety were used: the Test Anxiety Scale (TAS) [Sarason, 1958], the Lack of Protection Scale (LP) [Sarason, 1958], and Bendig's version of the Manifest Anxiety Scale (MAS) [Bendig, 1956]. The two sets of instructions differed in that one set was designed to pose a personal threat to the subject and the other set was designed to reassure the subject. The results showed that TAS and LP, but not MAS, significantly interacted with the instructions." From Psyc Abstracts 36:01:3HK65S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sleep deprivation in adolescents and adults: Changes in affect.

The present study investigated the impact of sleep deprivation on several aspects of affective functioning in healthy participants selected from three different developmental periods: early adolescence (ages 10–13), midadolescence (ages 13–16), and adulthood (ages 30–60). Participants completed an affective functioning battery under conditions of sleep deprivation (a maximum of 6.5 hours total sleep time on the first night followed by a maximum of 2 hours total sleep time on the second night) and rest (approximately 7–8 hours total sleep time each night for two consecutive nights). Less positive affect was observed in the sleep-deprived, compared to rested, condition. This effect held for 9 of the 12 positive affect items on the PANAS-C. Participants also reported a greater increase in anxiety during a catastrophizing task and rated the likelihood of potential catastrophes as higher when sleep deprived, relative to when rested. Early adolescents appraised their main worry as more threatening when sleep deprived, relative to when rested. These results support and extend previous research underscoring the adverse affective consequences of sleep deprivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computer-assisted communication and team decision-making performance: The moderating effect of openness to experience.

This study examined the effects of computer-assisted communication on team decision-making performance as a function of the team's openness to experience. 79 teams performing a multiple-cue probability learning task were randomly assigned to 1 of 2 experimental conditions: (a) verbal communication or (b) computer-assisted communication (which combined verbal and computerized communication). The results indicated that access to computer-assisted communication improved the decision-making performance of teams, but only when the teams were high in openness to experience. This effect was observed using both global openness and more specific openness facets, as well as a variety of team-level aggregation strategies. Moreover, the beneficial effects of openness in computer-assisted conditions were mediated by the efficiency with which teams integrated verbal and computerized forms of communication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)