Mechanisms of visual-cognitive aging: A neural network account

Two neural network simulations were run for the purpose of specifying the network parameters that best describe age-related interindividual and intraindividual variability in figure completion performance. the network architecture was modified in three ways that corresponded to plausible computational and neuro-anatomical constraints. In two simulations in which the rate of increase of activation within network units was constrained during testing, the performance of the network closely resembled the relevant empirical data. These findings supported a computationally specific model of age-related differences in figure completion performance rather than a diffuse model of age-related slowing. It is suggested that the analysis of fit between the results of computer simulations and analogous empirical data provides a useful method for the explication of aging mechanisms, and for distinguishing among competing hypotheses and constructs in the study of cognitive aging.     

Effects of aging on voluntary and involuntary shifts of attention

Abstract

This experiment examined adult age differences in the speed and accuracy of voluntary and involuntary shifts of visual attention. Younger and older adults performed two spatial cuing tasks using central cues and abrupt onset peripheral cues presented at stimulus onset asynchronies (SOAs) of 100, 150, 200, 250, and 300 ms. Analyses of the magnitudes of cuing effects revealed a similar time course for younger and older adults in the central cue condition, but not in the peripheral condition. Analyses of the Brinley plot for central cues across cue validity conditions indicated that as much as 93% of the variance could be attributed to age-related general slowing rather than to differential aging of a specific visual orienting mechanism.     

Is there an age deficit in the selection of mental sets?

Efficient selection of actions is dependent on higher-level constraints (mental sets) on lower-level selection. This paper explores the hypothesis that ageing leads to specific impairments associated with higher-level selection between mental sets. Indirect evidence for such a deficit comes from occasional findings of age differences in situations with high executive-control demands (e.g., Mayr & Kliegl, 1993) that are not easily explained in terms of other factors, such as general slowing or working memory parameters. More direct evidence comes from recent results with the so-called task-switching paradigm. Specifically, age-sensitive set-selection processes are indicated by age differences in “global selection costs” (i.e., the response-time difference between task-switching blocks and single-task blocks) which seem to be particularly large when demands in terms of “keeping competing mental sets apart” are high. Finally, data from a new variant of the task-switching paradigm (the “fade-out paradigm”) are reported which show that age differences in global costs persist substantially beyond a phase in which set-selection is actually necessary. Generally, evidence is consistent with the view that in older age, a costly set-selection mode of processing dominates over the more efficient within-set-selection mode of processing, possibly because of a problem with maintaining distinct representations of what ought to be done in the face of competing representations of what could be done in principle.     

Influences of visibility,intentions, and probability in a peripheral cuing task

According to the concept of direct parameter specification, nonconsciously registered information can be processed to the extent that it matches currently active intentions of a person. This prediction was tested and confirmed in the current study. Masked visual information provided by peripheral cues led to reaction time (RT) effects only if the information specified one of the required responses (Experiments 1 and 3). Information delivered by the same masked cues that did not match the intentions was not used. However, the same information influenced RT if it was provided by visible cues (Experiments 2 and 3). The results suggest that the processing of nonconsciously registered information is flexible because it is susceptible to the changing intentions of a person. Yet, these processes are apparently restricted, as nonconsciously registered information cannot be used as easily for purposes not corresponding to the currently active intentions as better visible information.     

Musiktherapie in der deutschen Psychosomatik

The authors report about the clinical implementation of music therapy in psychosomatic hospitals in FRG based on a survey among practising music therapists: attending especially to the qualification of music therapists, their integration and the problem of indication. The coverage of music therapy in the standard textbooks on psychosomatic medicine is discussed.Finally the state of research on music therapy in psychosomatic hospitals is reviewed.