Dual-task performance as a function of adult age and task complexity

A dual-task procedure was used to examine capacity demands of letter-matching in younger and older adults. Older subjects generally were slower on both tasks than were younger adults, but this difference was especially pronounced for the late stages of category matching, suggesting that retrieval and comparison of category information is particularly demanding for older adults.     

Inter-hemispheric recruitment as a function of task complexity,age and cognitive reserve

In a behavioral divided visual field study, we investigated the efficiency of inter-hemispheric cooperation according to (1) task computational complexity (physical-identity versus name-identity letter matching), (2) age (younger versus older adults) and (3) educational attainment, used as a proxy for cognitive reserve. Overall, the results indicated a shift from within- to across-hemisphere processing advantage with increasing task complexity, suggesting that bilateral engagement leads to enhanced performance under high-demand conditions. This pattern was influenced by age, with older adults showing no within-hemisphere advantage in the simpler task and a greater across-hemisphere advantage in the more complex one, consistent with an age-compensatory view of inter-hemispheric recruitment. Moreover, for older adults, more years of education was associated with a weaker across-hemisphere advantage. Thus, we propose that cognitive reserve may account for bilateral engagement efficiency. Finally, the groups differed in terms of laterality effects, with only younger adults demonstrating a left visual field advantage in the name-identity task, lending some support to the right hemi-aging hypothesis.     

Attention and memory cues in concept learning as a function of task complexity and age

The effects of attention and memory cues on concept learning performance were investigated as a function of task complexity and grade level of Ss. It was found that: (1) the attention and memory cues were closely interrelated in their effects upon performance with both significantly improving performance at all but the lowest levels of complexity; (2) both types of cues considerably lessened the effect of stimulus complexity upon performance; and (3) the attention cue elicited the best performance from Ss in the first through ninth grades, while the memory cue elicited the best performance from 4-year-old and kindergarten Ss.     

Information search and choice accuracy as a function of task complexity and task structure

Previous research has consistently shown that subjects switch to noncompensatory information search behaviour when task complexity increases. However, a rather specific class of tasks was used in these studies for which complete information search is not necessary to attain accurate task performance. In the present study information search behaviour, choice accuracy, subjective difficulty and confidence were registered under various task complexity conditions in two different task environments. In the first task, subjects had to make a choice between apartments; in the second task, a choice was required between baskets containing groceries of different prices. Forty subjects made choices by means of computerized information boards. The results showed effects of both complexity and type of task on information search behaviour. The lowest proportion of requested information and the most variable search pattern was observed for the apartments task in the complex task condition. However, accuracy remained constant over all complexity conditions. Together, the results suggest that under high task complexity levels subjects try to work smarter rather than harder. In the context of a choice requirement the specific task structure may allow them to switch to noncompensatory strategies while maintaining accuracy and avoiding the integration of large amounts of information.     

Endogenous visuospatial precuing effects as a function of age and task demands

This experiment examined the effects of age on processing resource capacity using an endogenous visuospatial precuing task and four levels of resource demands. Younger and older adults made speeded two-choice responses to dim and bright targets that required a line-orientation or a lexical decision. An arrow preceding target onset served as an attentional cue to affect the spatial distribution of resources. It provided accurate information about the target’s location on most trials and inaccurate or neutral information on the remaining trials. Although older adults were slower than younger adults under all conditions and were more affected by the resource demand manipulations, they exhibited a pattern of precuing effects across conditions that was similar to that of the younger adults. Results are consistent with the idea that the visuospatial attention system remains relatively unaffected by aging. However, the data speak against the idea that capacity reduction is the primary contributor to age-related slowing.     

Handedness as a function of test complexity.

Handedness as a function of test complexity was investigated with two tests, Dotting and Tapping-on-squares. For each one three levels of complexity were established by varying radius (Dotting) and square sides (Tapping-on-squares). Administration of the different complexity levels to a total of 310 third and fourth grade boys and girls showed that the rate of left-handedness increased from 6% to 16% with decreasing level of test complexity. It is concluded that optimal classification of handedness is only made possible by maximal levels of test complexity, which have to be established empirically for different populations.     

Errors of commission as a function of age and temperament in a type of vigilance task

Forty subjects monitored a 40 min. series of 10-sec. intervals containing digits (spoken at the rate of 1 per sec.), each followed by 10-sec. silence. The task was to report whether or not three consecutive and different odd digits occurred. Responses were forced. The results showed that there was no correlation between either age or temperament and the number of correct detections made. Older subjects, however, made more errors of commission, and were less able to distinguish wanted from unwanted events. The younger and introverted subjects appeared to be more cautious. The data is discussed in terms of the arousal theory of vigilance performance.     

Cue enhancement as a function of task set

The hypothesis was tested that the intention to use a particular cue relation would enhance the effectiveness of that particular cue in determining the resulting perception. For this purpose, a situation was presented in which the apparent depth position of an object in a configuration of objects would differ depending upon which of two possible cue relations (size cues) were used. The results support the conclusion that the perceived depth position of the object differed in the expected directions as a function of the task set. The data of the study are discussed with respect to the “adjacency principle” which states that cue efficiency is determined by the relative adjacency of objects between which the cues occur. Although the effect of cue set upon the perception seems to be small compared with that of adjacency, it cannot completely be ignored.     

Policy conflict and policy change as a function of task characteristics II. The effect of task predictability

Brehmer, B. Policy conflict and policy change as a function of task characteristics. II. The effect of task predictability. Scand. J. Psychol., 1973, 14, 220–227.-The hypothesis, derived from experimental studies on policy formation, that the level of agreement reached in a policy conflict situation is positively related to the predictability of the policy task was tested in an experiment conducted in the "lens model" interpersonal conflict paradigm. The results supported the hypothesis, and showed the lower level of agreement in the low task predictability condition was due to the fact that the subjects' policies were less consistent in that condition. The similarity of the systematic aspects of the subjects' policies, on the other hand, was not affected by task predictability.     

Memory for orientation of forms as a function of their meaningfulness and complexity.

Accuracy of memory for left-right orientation of single figures varying in meaningfulness and complexity was studied in subjects from kindergarten to adulthood. Complexity was an unimportant variable. Orientation of meaningful figures was remembered better than orientation of nonmeaningful figures at all ages. There were no developmental differences in memory for meaningful figures beyond kindergarten, but pronounced developmental differences were found in memory for nonmeaningful figures. It was proposed that a decision to store orientation information is dependent upon a judgment about the meaningfulness of a presented figure, and that young children have more difficulty than adults in finding meaningfulness in unfamiliar forms. The decision to store appears to occur automatically, since there was only a small difference between conditions in which subjects were informed or not informed to remember orientation. It was also suggested that part of the often reported difficulty in remembering diagonal orientation may be due to the symmetry of the diagonal forms typically investigated.     

Conformity as a function of task generalization and relative competence

Subject correctness and group agreement were varied for college subjects engaged in a light discrimination task. On another task, employing multiple-choice questions about Canada, the dependent variable of conformity was assessed to examine generalization of relative competence formed on the light discrimination task. It was seen that (1) relative competence was seen to mediate conformity for a specific task (Canadian Knowledge Inventory), but did not generalize across tasks (i.e. from the light discrimination task to the Canadian Knowledge Inventory); (2) with respect to the Canadian Knowledge Inventory, subjects who perceived themselves as more competent than the group did not conform as much as those who either perceived themselves as less competent than or as competent as the group; (3) the experimental manipulations did not affect conformity, further supporting the findings that perceived competence does not generalize across classes of tasks; (4) females conformed more than males: and (5) nonsuspicious subjects conformed more than suspicious subjects.