A NOTE ON THE CROSS-NATIONAL DIFFERENCES IN COGNITIVE CONFLICT FOUND BY HAMMOND et al.1

It is shown that the differences in cognitive conflict between American and Western European subjects found by Hammond, Bonauito, Faucheux, Moscovici, Fröhlich, Joyce, and Di Majo (1968) can be explained by differences in procedure between the American and European experiments in the Hammond et al. study.     

NOTE ON THE EFFECT OF VELOCITY ON PERCEIVED DURATION

Ten subjects made magnitude productions of duration in two velocity conditions when going by car. Productions for the higher of the two velocities were found to be reliably longer than those for the lower due to a negative relation between velocity and the slope of the R-S function relating perceived to physical duration. It was suggested that the effect of velocity on the slope of the R-S function might account for the discrepant results from previous studies investigating the effects of velocity on perceived duration.     

Effect of cue validity on learning of complex rules in probabilistic inference tasks

The effect of cue validity on the learning of positive and negative J-shaped relations in single-cue probability learning was studied. As would be expected from a hypothesis construction model, learning of the J-shaped relations was better when cue validity was high than when it was low. However, the results also showed that positive J-rules were learned more efficiently than negative J-rules. This shows that subjects do not construct their hypotheses on the basis of data from task only. It was concluded that subjects construct their hypotheses from elements stored in memory, and that data are used only to test their hypotheses.     

EFFECTS OF COMMUNICATION AND FEEDBACK ON COGNITIVE CONFLICT

BREHMER, B. Effects of communication and feedback on cognitive conflict. Scand. J. Psychol. , 12, 205–216.–The effects of communication and feedback upon policy similarity and policy consistency in cognitive conflict were studied in a 2×2×5 factorial experiment with communication (present/ absent), feedback (present/absent) and blocks of trials as the factors. Communication increased policy similarity and agreement, but feedback had no effect. Both subjects with linear and subjects with nonlinear policies gave up more of their initial policy in the communication condition, but only the nonlinear subjects managed to utilize communication to acquire new policies. In all conditions, including the condition without feedback and communication, the nonlinear subjects' policies were less consistent than those of the linear subjects. This suggests that nonlinear policies may be less stable than linear policies.     

Achieving what cannot be done: coping with the time constants in a dynamic decision task by doing something else

This study examines how people handle the time constants in dynamic decision tasks, using a microworld called NEWFIRE which simulates forest fire fighting. The results showed that the participants did not adapt to the time constants, as shown by the fact that they did not discriminate between fires requiring different number of fire fighting units when varying the number of fire fighting units was a means of compensating for the time constants. If they were allowed to move units before the fire started their performance improved, suggesting that they could compensate for their problems with the time constants by restructuring the task in such a way that they did not need to consider them. It is suggested that such restructuring may well be how people handle dynamic tasks also in other circumstances, and that more effort should be put into studying what people actually do in dynamic tasks, rather than into only assessing whether or not they perform optimally.     

Comparing memory skill maintenance across the life span: preservation in adults, increase in children

The authors examined life-span differences in the maintenance of skilled episodic memory performance by assessing 100 individuals (10 -11, 12-13, 21-26, and 66-79 years old) 11 months after termination of an intensive multisession mnemonic training program (Y. Brehmer, S.-C. Li, V. Müller, T. von Oertzen, & U. Lindenberger, 2007). Skill maintenance was tested in 2 follow-up sessions, the first without and the second with mnemonic reinstruction. Younger and older adults' average performance levels were stable across time. In contrast, both younger and older children's memory performance improved beyond originally attained levels. Older adults' performance improved from the first to the second follow-up session, presumably profiting from instruction-induced skill reactivation. Results suggest that (a) skill maintenance is largely intact in healthy older adults, (b) older adults need environmental support to fully reactivate their former skill levels (cf. F. I. M. Craik, 1983), and (c) children adapt a skill learned 11 months ago to their increasing cognitive capabilities.     

Note on subjects' hypotheses in multiple-cue probability learning

Subjects' hypotheses in multiple-cue probability learning was studied by trial-by-trial verbal reports in tasks with linear and nonlinear cue-criterion relations. In accordance with earlier findings, the results of the present experiment show that subjects learned linear tasks rapidly, while nonlinear tasks were not learned at all. The subjects' verbal hypotheses show that the subjects were concerned with rules for combining cue values, rather than with cue-criterion functions. This explains why the subjects fail to learn nonlinear multiple-cue tasks. It also shows that, although the subjects seem to learn multiple-cue tasks through a hypothesis testing process of the same kind as in single-cue probability tasks, the hypotheses tested in multiple-cue tasks are different from those tested in single-cue tasks. Finally, the present results suggest that the picture of the subjects' cognitive models of multiple-cue probability learning tasks provided by the customary multiple regression analysis may be fundamentally misleading in that it suggests that the subjects learn the validity of each cue rather than a combination rule.     

Plasticity of brain and cognition in older adults

Aging is typically related to changes in brain and cognition, but the aging process is heterogeneous and differs between individuals. Recent research has started investigating the influence of cognitive and physical training on cognitive performance, functional brain activity, and brain structure in old age. The functional relevance of neural changes and the interactions among these changes following interventions is still a matter of debate. Here we selectively review research on structural and functional brain correlates of training-induced performance changes in healthy older adults and present exemplary longitudinal intervention studies sorted by the type of training applied (i.e., strategy-based training, process-specific training, and physical exercise). Although many training studies have been conducted recently, within each task domain, the number of studies that used comparable methods and techniques to assess behavioral and neural changes is limited. We suggest that future studies should include a multimodal approach to enhance the understanding of the relation between different levels of brain changes in aging and those changes that result from training. Investigating inter-individual differences in intervention-induced behavioral and neuronal changes would provide more information about who would benefit from a specific intervention and why. In addition, a more systematic examination of the time course of training-related structural and functional changes would improve the current level of knowledge about how learning is implemented in the brain and facilitate our understanding of contradictory results.     

Memory plasticity across the life span: uncovering children's latent potential

Memory plasticity, or the ability to improve one's memory performance through instruction and training, is known to decline during adulthood. However, direct comparisons among middle childhood, adulthood, and old age are lacking. The authors examined memory plasticity in an age-comparative multisession training study. One hundred and eight participants ages 9-10, 11-12, 20-25, and 65-78 years learned and practiced an imagery-based mnemonic technique to encode and retrieve words by location cues. Individuals of all ages were able to acquire and optimize use of the technique. Older adults and children showed similar baseline performance and improvement through mnemonic instruction. However, in line with tenets from life-span psychology (P. B. Baltes, 1987), children profited more from mnemonic practice and reached higher levels of final performance than did older adults.