Aging and shifts of visual spatial attention.

Three experiments examined adult age differences in the efficiency of endogenous (voluntary) and exogenous (involuntary) attention shifts. Younger and older subjects performed a spatial cuing task in which abruptly onset peripheral cues (Experiment 1) or central, symbolic cues (Experiments 2 and 3) were presented before a target stimulus at intervals ranging from 50 to 250 ms. With peripheral cues, the magnitude of cuing effects was at least as great for older as for younger adults and followed a similar time course. Similar results were obtained with symbolic cues, although cuing effects for older adults varied with cue difficulty. The results suggest that cue encoding may decline with advancing age but that the efficiency of the shift process is preserved.     

An examination of the effects of adult age on explicit and implicit learning of figural sequences

Memory for previously learned figural sequences and item-to-item covariations within figural sequences was examined under explicit and implicit instructional conditions in three age groups: young adults (17-23 years); middle-aged adults (35-45 years); and older adults (55-65 years). In Phase 1 of the experiment, the acquisition phase, half the subjects in each age group learned sequences of three to eight items in which the item-to-item changes conformed to an artificial grammar, and the other half of the subjects in each age group learned strings in which the item-to-item changes were nongrammatical. In Phase 2, the implicit/explicit test phase, subjects made forced-choice judgments about parts of the strings that they learned in Phase 1, under either explicit or implicit instructions. Analyses of Phase 2 data revealed that subjects in both instructional conditions used item-to-item covariations in making decisions about grammatical strings. However, use of previously learned covariations as well as the number of correct judgments about previously learned strings was greater in the explicit condition than in the implicit condition. An age-related deficit was found for explicit recognition of grammar-following sequences.     

Impaired semantic memory during acute transient global amnesia

As a clinical model of hippocampal dysfunction, transient global amnesia (TGA) causes reversible memory disturbance. While episodic memory deficits in TGA patients have been extensively described, data regarding semantic memory involvement are sparse and contradictory. We report impaired semantic fluency performance in 16 patients with hippocampal lesions on MRI during acute TGA compared to their performance one day later and to that of 20 healthy subjects. Our findings support the involvement of the hippocampus in semantic retrieval.     

The associative-memory basis of cognitive skill learning: adult age differences

It has been established that memorizing common problems and their solutions underlies cognitive skill development, and that there are substantial age deficits in the rate of this learning. In a between-groups design, the authors compared learning rates for the same set of problems in skill (SK) training and paired-associate (PA) training. The authors found main effects due to condition (PA problems were acquired earlier) and to age (older adults' learning was delayed), but no condition-by-age interaction. The authors concluded that the age deficit in SK can be accounted for by the age deficit in associative memory; no further explanation is needed. The authors also analyzed fast and slow retrieves in SK and PA, and found that the frequency of fast retrieves did not differ in the two conditions. The overall advantage of PA was due to the occurrence of slow retrieves, which were absent in SK presumably because the skill algorithm displaces slow, explicit memory search in SK, but not fast, familiarity-based retrieval.     

Separating optimism and pessimism: a robust psychometric analysis of the revised Life Orientation Test (LOT-R)

The internal structure of the revised Life Orientation Test (LOT-R, German version; M. F. Scheier, C. S. Carver, & M. W. Bridges, 1994) was analyzed in a sample of 46,133 participants who ranged in age from 18 years to 103 years. Confirmatory factor analysis showed that dispositional optimism, as measured by the LOT-R, is bidimensional, consisting of an Optimism and a Pessimism factor. Consistent with previous results, there were small to moderate negative correlations between Optimism and Pessimism, but the strength of the association continuously decreased with age. The relative independence of the 2 dimensions occurred in both genders and across different age groups of patients with different medical disorders.     

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.     

The Struggle of Behavioral Therapists With Exposure: Self-Reported Practicability,Negative Beliefs,and Therapist Distress About Exposure-Based Interventions

Exposure-based interventions are a core ingredient of evidence-based cognitive-behavioral treatment (CBT) for anxiety disorders, posttraumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD). However, previous research has documented that exposure is rarely utilized in routine care, highlighting an ongoing lack of dissemination. The present study examined barriers for the dissemination of exposure from the perspective of behavioral psychotherapists working in outpatient routine care (N = 684). A postal survey assessed three categories of barriers: (a) practicability of exposure-based intervention in an outpatient private practice setting, (b) negative beliefs about exposure, and (c) therapist distress related to the use of exposure. In addition, self-reported competence to conduct exposure for different anxiety disorders, PTSD, and OCD was assessed. High rates of agreement were found for single barriers within each of the three categories (e.g., unpredictable time management, risk of uncompensated absence of the patient, risk of decompensation of the patient, superficial effectiveness, or exposure being very strenuous for the therapist). Separately, average agreement to each category negatively correlated with self-reported utilization of exposure to a moderate degree (-.35 ≤ r ≤ -.27). In a multiple regression model, only average agreement to barriers of practicability and negative beliefs were significantly associated with utilization rates. Findings illustrate that a multilevel approach targeting individual, practical, and systemic barriers is necessary to optimize the dissemination of exposure-based interventions. Dissemination efforts may therefore benefit from incorporating strategies such as modifying negative beliefs, adaptive stress management for therapists, or increasing practicability of exposure-based interventions.     

Rules and more rules: The effects of multiple tasks, extensive training, and aging on task-switching performance

Task-switching performance was assessed in young and older adults as a function of the number of task sets to be actively maintained in memory (varied from 1 to 4) over the course of extended training (5 days). Each of the four tasks required the execution of a simple computational algorithm, which was instantaneously cued by the color of the two-digit stimulus. Tasks were presented in pure (task set size 1) and mixed blocks (task set sizes 2, 3, 4), and the task sequence was unpredictable. By considering task switching beyond two tasks, we found evidence for a cognitive control system that is not overwhelmed by task set size load manipulations. Extended training eliminated age effects in task-switching performance, even when the participants had to manage the execution of up to four tasks. The results are discussed in terms of current theories of cognitive control, including task set inertia and production system postulates.