Differential effects of task complexity on contextual interference in a drawing task

A large number of studies demonstrated the beneficial effects of contextual interference (CI) created by a random practice of different task variations during training on the retention and transfer of motor skills. Current interpretations of this phenomenon assume that random practice engages the subjects in deep and elaborate processing of movement related information, whereas blocked practice results in more superficial processing leading to poorer performance on later retention and transfer tests. According to this line of interpretation, we hypothesised that the complexity of the task to be learned could modulate the effects of CI. If the task is sufficiently complex, it could force the subjects to rely on such elaborate processing, and the beneficial effects of the intertask interference created by random practice could be obscured in that case. We tested this hypothesis by analysing the effects of practice schedule (random vs. blocked), on the acquisition, retention and transfer of learning in a drawing task where subjects had to reproduce accurately, without visual control, geometrical patterns presented on a video screen, as a function of task complexity defined by the number of segments (two, three or four) of each pattern. The results indicated a clear beneficial effect of random over blocked practice on delayed retention and transfer. However, this CI effect was only observed in subjects who learned the simplest movements, and was not observed in subjects who practised the more complex task. These results are discussed in terms of intratask interference created by the planning of multiple movements and the processing of knowledge of results (KR) when the number of drawing movements is increased. These findings support the assumption that the level of cognitive effort in which the subjects are engaged during training is a main factor influencing long-term retention and transfer of motor skills.     

The influence of degree of expertise and objective task complexity on perceived task complexity and performance.

Research on expertise has shown that nonexperts may sometimes outperform experts. Some researchers have suggested that superior performance by experts depends on the match between the experts' cognition and the demands of the task. The authors explored this issue using a quasi-experiment set in an organization. They examined how 3 sets of similar tasks that differ in their type of complexity can lead to differences in task perceptions and performance among experts, intermediates, and novices. The results suggest that experts and novices pay attention to different aspects of a task and that this affects both their perceptions of task complexity (i.e., task analyzability and variability) and their performance on the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of task complexity and time pressure upon team productivity.

Using 72 college students as Ss, team productivity was studied under a contract with the Office of Naval Research. 24 3-man teams performed assembly tasks under 2 levels of difficulty and 3 levels of time pressure. The task should be complex enough to reduce boredom but not exceed a moderate acceleration of time pressure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of negation and task complexity on illusory correlation.

In 3 experiments with a total of 463 undergraduates, signs, disorders, or both signs and disorders were negated. Exp I negated the disorder but resulted in no reduction in illusory correlation, measured several ways. Exp II replicated Exp I but informed Ss that some of them would be in a zero-relationship condition. Again, no reduction in illusory correlation was found. Exp III included conditions negating not only the disorder but also the sign and the sign and the disorder, and again no reduction due to negation was obtained. An additional experiment (153 Ss) manipulated the number of disorders per sign and resulted in significant effects due to complexity. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating effects of task complexity on the relationship between regulatory foci and safety and production performance.

Regulatory foci of promotion and prevention have been shown to relate differentially to occupational safety and production. This research proposes that task complexity can help explain the differences reported between these 2 self-regulatory processes and safety and productivity performance. Results revealed that promotion is positively related to production and prevention is positively related to safety regardless of task complexity. However, when task complexity is high, promotion negatively relates to safety and prevention negatively relates production. Implications for work motivation theory and research, as well as avenues for future research, are discussed. Practical implications for managerial interventions to optimize both safety and productivity are also presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Redundancy gain in discrimination of colored lights: effects of complexity and eccentricity

The present study investigated the redundancy gain in discrimination of colored lights. Subjects were requested to discriminate a target from 34 nontarget lights differing from the target in luminance, hue, or both, and RTs were recorded. Experimental variables were the complexity of stimulus pattern and the eccentricity of the target in visual angle. The 35 lights were arranged regularly on an imaginary grid in the low-complexity condition and were arranged randomly in the high-complexity condition. The eccentricity of target was varied from 0 degree to 16 degrees. Only when the stimulus pattern was highly complex and eccentricity was large, the combination of luminance and hue made the subject's discrimination faster than when luminance or hue individually operated as a cue for discrimination. That is, a redundant target effect was found only for a highly complex stimulus pattern and in peripheral vision.     

Effects of temperature, clothing, and task complexity on task performance and satisfaction.

Examined the effects of room temperature, clothing, and task complexity on task performance and satisfaction. 120 18–22 yr old male college students worked on either a mathematical problem-solving task or a collating task. Room temperature was maintained at either 65 or 78Φ during the task session. Ss were requested to wear either a suit (or sport coat), long sleeve shirt, and tie; or a short-sleeve shirt with no tie. Ss were administered the Minnesota Satisfaction Questionnaire. Results show that Ss wearing appropriate clothing for the temperature conditions showed higher levels of performance and satisfaction with the working condition than did those wearing inappropriate clothing, regardless of task complexity. Similar results were found for intrinsic task satisfaction only for the simpler task. (12 ref) (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)     

The effects of amplitude modulation on acoustic reflex decay

The temporal decay of the acoustic reflex provides the basis for an objective audiological test that differentiates cochlear from retrocochlear pathologies. The classic sign of a neural lesion is a rapid decay of the reflex under conditions of pure-tone stimulation for frequencies of 1,000 Hz and below. This restriction to lower frequencies is due to the fact that even normal ears show decay for higher-frequency signals. At present, it is unclear whether the acoustic reflex decay (ARD) seen in normal ears is related to frequency-specific channels or whether the critical variable is the timing information coded within the channels. This study examined ARD in subjects with normal hearing and middle ear function. The degree of ARD was measured for both modulated and unmodulated carrier frequencies of 500, 1,000, 2,000 and 4,000 Hz with amplitude modulation rates of 50-400 Hz. The dependent variable was the half-life of the decaying reflex (ARD 50%) over a 20-second stimulation interval. Significant ARD was present for high-frequency unmodulated carriers but not for low-frequency carriers. For all listeners, ARD was diminished for all modulated stimuli. The results of this study suggest that resistance to ARD is mediated by both the temporal aspects and frequency of a stimulus.     

Age-related deficits in prospective memory: The influence of task complexity.

Younger and older Ss were asked to perform an action whenever target words occurred during a short-term memory task. The difficulty of this prospective memory task was manipulated by varying the delay preceding the occurrence of a target event and by varying the number of different target events. Age-related performance differences emerged when there were several different target events but not when there was 1 target event presented several times. Age-related performance differences, when they occurred, were associated with poorer retrospective memory for the target events. The results were interpreted in terms of a componential analysis of prospective memory, which assumes both similarities and differences between prospective and retrospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of recent practice on task switching.

Four experiments investigated the effect of recent selective practice on the cost of switching between 2 tasks afforded by letter-digit pairs: alphabet arithmetic and shape comparison. Experiments 1 and 2 found a greater cost associated with switching to the more recently practiced task: evidence that task-set inertia contributes to switching costs. Experiment 3 found this effect to be limited to trials on which a recently trained stimulus followed another such stimulus: a result problematic for all current theories of task-set priming. Experiment 4 showed that the effect of recent practice was eliminated by active preparation for a task switch: It appears that endogenous task-set preparation reduces the effects of task-set inertia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of variation in task complexity and displayed information on operator performance.

An experiment was conducted to determine the effects of amount of information displayed, level of task difficulty, and practice on performance speed and accuracy for a visual motor task. Based on results from 16 Ss, it was concluded that an increase in the number of cues available for visual reference will not necessarily affect performance. Further cooroborative evidence was obtained for the hypothesis that the criterion of redundancy in displayed information should be based on perceptual usefulness of the cues provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of complexity on jurors' verdicts and construction of evidence.

One hundred twenty mock jurors heard 1 of several versions of a civil trial. The tort trial was either high or low in information load and contained evidence that either clearly favored the plaintiffs or was ambiguous. Expert witnesses testified in either technical or less technical language. Verdicts favored the plaintiffs when the evidence was clear and was presented in technical language because technical language enhanced witnesses' credibility when the evidence was clear. Although high information loads and technical language hindered evidence processing, jurors endeavored to comprehend, as indicated by the recall of more facts and alternative constructions of the evidence when that evidence was ambiguous. However, those constructions were of poorer quality, incorporating evidence of lesser probative value. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of task complexity on reaction times in memory scanning and visual discrimination in Parkinson's disease

Within the context of the bradyphrenia debate, two experiments designed to measure the cognitive speed of Parkinson patients (PD) were conducted with 58 subjects. The experiments took the form of a high-speed memory scanning task using memory sets consisting of one-six words or one-six abstract figures. In a visual discrimination task, two simultaneously presented abstract images had to be compared, the complexity of the images being varied through four stages. Motor response was constant, reaction time was the dependent variable. PD differed from matched controls in the level (significant only in scanning) but in neither experiment in the slope of reaction time curves. Interaction group x complexity (MANOVA) was not significant. Correlations between disease parameters and a 'complexity effect' measure were low throughout. However, the link to general intelligence was significant. The findings contradict the conventional bradyphrenia hypothesis.     

The effects of groups' variety and disparity on groups' cognitive complexity.

This study examined the influence of group diversity conceptualized as disparity and as variety on group cognitive complexity. Data on individual cognitive complexity and group cognitive complexity were collected in 44 groups using a conceptual mapping technique. Also data on the quality of teamwork processes and satisfaction were collected using an individual questionnaire. The results indicate that (a) gender variety has a positive impact on group cognitive complexity, (b) cognitive disparity has a negative impact on group cognitive complexity, and (c) groups with a high average individual cognitive complexity have the highest cognitive complexity as a group only if the quality of their interactions is high. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of a divisive gain control in human vision

Evidence for a divisive contrast gain control in human vision was obtained using a contrast version of the probe-on-flash technique that has been employed in the light adaptation literature. Thresholds were measured for a briefly flashed (30 ms), vertical test pattern superimposed on a cosine mask as a function of time after mask onset (SOA). Threshold elevations declined monotonically for SOAs up to 150 ms. and exhibited an exponential time course with an average time constant of 51 ms. Increment thresholds for the test as a function of mask contrast provide direct evidence that these effects are due to operation of a divisive gain control within the first 150 ms after stimulus onset. Experiments to measure the spatial spread of this gain control show it to be localized to a region of no more than 45 arc min radius.     

Effects of task complexity and verbal evaluation on the learning of normals and schizophrenics.

Tested the relative predictive powers of 3 theories of schizophrenia: S. A. Mednick's (see 33:5) drive theory; E. H. Rodnick and N. Garmezy's censure-deficit theory; and R. Atkinson and N. M. Robinson's (see 36:4) censure-sensitivity theory. 30 normals, 30 process schizophrenics, and 30 reactive schizophrenics were each run in a low- and high-complexity verbal discrimination task. 1/2 of each group was praised for correct responses, 1/2 censured for incorrect ones. While normals did not respond differentially to the reinforcers, schizophrenics tended to learn faster when censured than when praised, supporting Atkinson and Robinson. The performance decrement from the low- to the high-complexity task was equivalent for all groups, which is nonsupportive of Mednick's theory. An alternative explanation of the results is offered and a cautious interpretation of the data is urged due to medication differences between normals and schizophrenics. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Additive effects of task difficulty and goal setting on subsequent task performance.

Notes that the setting of difficult goals has been consistently found to improve performance in both laboratory and field settings; however, the setting of difficult goals has sometimes been confounded with the difficulty of the task especially in field studies where the difficulty of goals and more complex tasks often co-vary. The present study investigated the relative contribution of goal setting and task difficulty to performance on chess problems. Employing a 3 * 3 factorial design, 82 chess-playing undergraduates attempted to solve either easy, moderately difficult, or difficult chess problems, after accepting either an easy, moderately difficult, or difficult goal. Results show that both goals and task difficulty contributed additively to task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)