Cognitive processes in aging effects on attentional alerting.

Alerting, the process of achieving and maintaining a state of optimal vigilance, is crucial for detecting relevant stimuli and task performance. Age-related decline in the ability to use alerting cues is widely reported and attributed to changes in noradrenergic signaling. However, it remains to be determined whether aging affects all forms of alerting cues equally and whether older adults differently modulate their alerting sensitivity based on differences in cue predictivity relevant to the target task. We examined the performance of 135 younger adults and 103 older adults on three versions of the Attention Networks Test, using locational but spatially nonpredictive visual cues, locational spatially predictive visual cues, and spatially predictive auditory cues. Analysis of alerting effects indicated that while older adults derived less benefit from visual alerting cues than younger adults, they used auditory alerting cues equally well. Furthermore, cue spatial predictivity did not impact on aging effects on alerting. This heterogeneity in aging effects on alerting may indicate that they result primarily from cognitive rather than neuromodulatory changes.

Predictivity and Manifestation Factors in Aging Effects on the Orienting of Spatial Attention.

OBJECTIVE: Prior attention research has asserted that endogenous orienting of spatial attention by willful focusing may be differently influenced by aging than exogenous orienting, the capture of attention by external cues. However, most such studies confound factors of manifestation (locational vs symbolic cues) and the predictivity of cues. We therefore investigated whether age effects on orienting are mediated by those factors. METHOD: We measured accuracy and response times of groups of younger and older adults in a discrimination task with flanker distracters, under three spatial cueing conditions: nonpredictive locational cues, predictive symbolic cues, and a hybrid predictive locational condition. RESULTS: Age differences were found to be related to the factor of cue predictivity, but not to the factor of spatial manifestation. These differences were not modulated by flanker congruency. DISCUSSION: The results indicate that the orienting of spatial attention in healthy aging may be adversely affected by less effective perception or utilization of the predictive value of cues, but not by the requirement to voluntarily execute a shift of attention.

Multifactorial effects of aging on the orienting of visual attention.

Differential sensitivity of brain areas to the effects of healthy aging may lead to multifactorial influences on the orienting of spatial attention. We examined how aging affects two key aspects of orienting: the benefits of orienting to valid spatial cues vs. the costs of re-orienting following invalid cues, and the impact on orienting of prior cue validity, in the context of different degrees of cue predictivity and types of cue manifestation. We analyzed accuracy and response time data from the performance of 103 older adults and 135 younger adults in three versions of the Attention Networks Test. Participants engaged in target discrimination following either locational cues that were generally non-predictive, locational cues that were generally predictive, or symbolic cues that were generally predictive. We found that healthy older adults did not exhibit greater re-orienting response time costs than younger adults across all cueing types, nor did they differ in the orienting benefits provided by predictive locational cues. However, older adults derived greater benefit from valid cues in a generally non-predictive cueing context, and lesser benefit from valid cues in a symbolic predictive cueing context. Additionally, aging had no impact on the effects of prior trial validity on subsequent trial validity benefits. A comprehensive appreciation of the effects of aging on attention may be informed by these distinctions.

Preserved left and upper visual field advantages in older adults' orienting of attention.

Lateralization of the distribution of attentional function in the brain is asserted to lead to asymmetry in attentional allocation. This is expressed in the phenomenon of pseudoneglect, in which line and object bisection judgments indicate left visual field (and presumably right hemisphere) dominance. Several studies indicate that this asymmetry is not found in old age, which is taken as an indication of decline in attentional function with aging. We examined this assertion using a more comprehensive assay of attentional asymmetry. We contrasted the spatial distribution of older and younger adults' visual attention using the Starry Night Task, a speeded visual search task in which targets must be located across a wide spatial distribution against a dynamic background of distracters. As expected, compared to younger adults, older adults' response times were longer overall. However, we found that older adults exhibited a graded left visual field advantage, even more distinctly than did younger adults. Additionally, older adults exhibited a graded upper visual field advantage equivalent to that of younger adults. These results indicate that aging may not necessarily compromise basic patterns of distribution of spatial attention. They do not support claims of aging-related loss of attentional lateralization.

A drop in performance on a fluid intelligence test due to instructed-rule mindset.

A 'mindset' is a configuration of processing resources that are made available for the task at hand as well as their suitable tuning for carrying it out. Of special interest, remote-relation abstract mindsets are introduced by activities sharing only general control processes with the task. To test the effect of a remote-relation mindset on performance on a Fluid Intelligence test (Raven's Advanced Progressive Matrices, RAPM), we induced a mindset associated with little usage of executive processing by requiring participants to execute a well-defined classification rule 12 times, a manipulation known from previous work to drastically impair rule-generation performance and associated cognitive processes. In Experiment 1, this manipulation led to a drop in RAPM performance equivalent to 10.1 IQ points. No drop was observed in a General Knowledge task. In Experiment 2, a similar drop in RAPM performance was observed (equivalent to 7.9 and 9.2 IQ points) regardless if participants were pre-informed about the upcoming RAPM test. These results indicate strong (most likely, transient) adverse effects of a remote-relation mindset on test performance. They imply that although the trait of Fluid Intelligence has probably not changed, mindsets can severely distort estimates of this trait.

Linguistic and emotional-valence characteristics of reading passages for clinical use and research.

Purpose: Fluency assessment in people who stutter (PWS) includes reading aloud passages. There is little information on properties of these passages that may affect reading performance: emotional valance, arousal, word familiarity and frequency and passage-readability. Our first goal was to present an extensive examination of these factors in three commonly used ("traditional") passages. The second goal was to compare a traditional passage to a new passage, designed to minimize the impact of these properties. Methods: Content words were rated (129 participants) on arousal, valence and familiarity. Other linguistic features were analyzed based on available datasets. This information was used to assess traditional passages, and to construct a new well-balanced passage, made of neutral, low-arousal and highly-familiar words. Readability for all passages was tested using formula-based and CLOZE tests (31 participants). Finally, 26 PWS were evaluated on fluency comparing the commonly used "Rainbow" passage with the novel one. Results: The three traditional passages contain a share of emotionally valenced (22-34%), high arousal (15-18%), lower familiarity (6-8%) and polysyllabic (5-9%) content words. Readability was highest for the novel passage (on formula-based scales). Average disfluencies percent for the Rainbow and our novel passage were not significantly different. Yet half of the individuals in this sample showed a large difference between the two passages. Conclusion: We provide detailed information on potential sources of variance using the traditional passages. Knowledge about these characteristics can inform clinical practice (and research). We suggest a combined procedure, using more than one passage to assess stuttering in individual cases.

Orienting of visual attention in aging.

Changes in attention are among the most important cognitive shifts associated with aging, with implications for maintenance of vocational competencies, participation in social interactions, and successful execution of activities of daily living. An important facet of attention is orienting, the ability to selectively attend a location or modality and thereby engender perceptual augmentation. Orienting also involves shifting of the focus of attention in response to unanticipated salient events. Aging may impact orienting through a variety of neurocognitive mechanisms and the interactions between them. We review findings regarding factors that mediate the impact of aging on orienting, including overt vs. covert attending, exogenous vs. endogenous processes, orienting benefits vs. reorienting costs, cue-target onset asynchrony (SOA), post-orienting task factors, and stage of aging. We also consider aging-related changes in the brain substrates of orienting, including cortical and white matter integrity, laterality, connectivity, neuromodulatory functions, and compensatory activity. Taken together, these findings suggest that healthy aging impacts performance on orienting tasks less through direct effects than via interactions with additional cognitive processes.

"Older is always better": Age-related differences in vocabulary scores across 16 years.

Cross-sectional studies of cognitive aging compare age groups at 1 time point. It is unclear from such studies whether age-related cognitive differences remain stable across time. We present a cross-sectional investigation of vocabulary scores of 2,000 younger and older adults collected across 16 years, using the same laboratory and protocol. We found a steady decrease with year of testing and an advantage for older adults. An additive relation between age group and year of testing implied that age-related differences in vocabulary are independent of changes over time, suggesting that younger and older adults are similarly affected by changes in word usage.

Mindset changes lead to drastic impairments in rule finding.

Rule finding is an important aspect of human reasoning and flexibility. Previous studies associated rule finding failure with past experience with the test stimuli and stable personality traits. We additionally show that rule finding performance is severely impaired by a mindset associated with applying an instructed rule. The mindset was established in Phase 1 (manipulation) of the experiment, before rule finding ability was assessed in Phase 2 (testing). The impairment in rule finding was observed even when Phase 1 involved executing a single trial (Experiment 2), and when entirely different stimuli and rules were used in the two phases of the experiment (Experiments 3-6). Experiments 4-6 show that applying an instructed rule in Phase 1 impaired subsequent (Phase 2) feedback evaluation, rule generation, and attention switching between rules, which are the three component processes involved in rule finding according to COVIS (Ashby, Alfonso-Reese, Turken, & Waldron, 1998).