Age differences in reading with distraction: Sensory or inhibitory deficits?

Two experiments examined how sensory acuity affects age differences in susceptibility to interference in the reading-with-distraction task. In both experiments, older and younger adults read texts in an italic font and were required to ignore distractor words in an upright font. Experiment 1 examined whether the age-related increase in distractibility can be simulated in younger adults by reducing their visual acuity. Experiment 2 investigated whether the age differences in distractibility disappear if visual acuity is equated across all participants in both age groups. Both experiments showed that an impairment in visual acuity leads to increased interference in the reading-with-distraction task. However, older adults were much more impaired by the distractor material than younger adults with reduced visual acuity (Experiment 1). The age differences in the reading-with-distraction task persisted when visual acuity was equated between older and younger adults (Experiment 2). We conclude that the age-related increase in susceptibility to interference in the reading-with-distraction task is not solely due to perceptual deficits of older adults but arises from a deficit in higher cognitive processes such as inhibitory attention. Nevertheless, sensory acuity has to be taken into account as a potential confounding factor in perceptually demanding visual attention tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Success and failure at dual-task coordination by younger and older adults.

Dual-task processing was explored in younger and older adults in 2 experiments that used a tone discrimination and a letter discrimination task. To encourage parallel processing if that was possible, the authors presented the stimuli for the 2 tasks simultaneously, and participants were instructed to withhold their responses until both were ready. The authors found no evidence for parallel processing and no evidence that the management of central processing of dual tasks is qualitatively different in older adults than it is in younger adults. When one response was verbal and the other manual, the 2 responses closely coincided. When both responses were manual, the authors did find that the first response was not delayed enough to coincide with the 2nd and that this underestimation was greater in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can Practice Overcome Age-Related Differences in the Psychological Refractory Period Effect?

Can dual-task practice remove age-related differences in the psychological refractory period (PRP) effect? To answer this question, younger and older individuals practiced 7 blocks of a PRP design, in which Task 1 (T1) required a vocal response to an auditory stimulus and Task 2 (T2) required a manual response to a visual stimulus (Experiment 1). The results showed that practice did not reduce, but rather increased, age-related differences in PRP interference. Using the trained individuals, the introduction of a less complex new T1 (Experiment 2) or a less complex new T2 (Experiment 3) with the task previously practiced reduced the PRP interference but only in older adults. The authors propose that older adults suffer from a large task-switch cost that is more sensitive to task complexity than to the amount of practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Now you see it, now you don't: Evidence for age-dependent and age-independent cross-modal distraction.

Age-related deficits in selective attention have often been demonstrated in the visual modality and, to a lesser extent, in the auditory modality. In contrast, a mounting body of evidence has suggested that cross-modal selective attention is intact in aging, especially in visual tasks that require ignoring the auditory modality. Our goal in this study was to investigate age-related differences in the ability to ignore cross-modal auditory and visual distraction and to assess the role of cognitive control demands thereby. In a set of two experiments, 30 young (mean age = 23.3 years) and 30 older adults (mean age = 67.7 years) performed a visual and an auditory n-back task (0 ≤ n ≤ 2), with and without cross-modal distraction. The results show an asymmetry in cross-modal distraction as a function of sensory modality and age: Whereas auditory distraction did not disrupt performance on the visual task in either age group, visual distraction disrupted performance on the auditory task in both age groups. Most important, however, visual distraction was disproportionately larger in older adults. These results suggest that age-related distraction is modality dependent, such that suppression of cross-modal auditory distraction is preserved and suppression of cross-modal visual distraction is impaired in aging. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Central cross-talk in task switching: Evidence from manipulating input–output modality compatibility.

Two experiments examined the role of compatibility of input and output (I-O) modality mappings in task switching. We define I-O modality compatibility in terms of similarity of stimulus modality and modality of response-related sensory consequences. Experiment 1 included switching between 2 compatible tasks (auditory–vocal vs. visual–manual) and between 2 incompatible tasks (auditory–manual vs. visual–vocal). The resulting switch costs were smaller in compatible tasks compared to incompatible tasks. Experiment 2 manipulated the response–stimulus interval (RSI) to examine the time course of the compatibility effect. The effect on switch costs was confirmed with short RSI, but the effect was diminished with long RSI. Together, the data suggest that task sets are modality specific. Reduced switch costs in compatible tasks may be due to special linkages between input and output modalities, whereas incompatible tasks increase cross-talk, presumably due to dissipating interference of correct and incorrect response modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of increased response dominance and contextual disintegration on the Stroop interference effect in older adults

In the study we considered the ability of the relative speed of processing-automaticity (RSOP-A) and contextual disintegration (CD) models of the Stroop interference effect to account for the age-related increase in Stroop interference typically observed in older adults. Findings from the first experiment were partially consistent with predictions of the RSOP-A model because response dominance was greater for older adults than for younger adults. However, the age-related increase in interference was independent of this increase in response dominance, suggesting that factors other than those postulated in the RSOP-A model contributed to the greater interference observed in older adults. Results of the second experiment were consistent with the CD model, which suggests that older adults had difficulty maintaining a color-naming strategy to guide task performance.     

Effects of age on cross-modal emotion perception.

Efficient navigation of our social world depends on the generation, interpretation, and combination of social signals within different sensory systems. However, the influence of healthy adult aging on multisensory integration of emotional stimuli remains poorly explored. This article comprises 2 studies that directly address issues of age differences on cross-modal emotional matching and explicit identification. The first study compared 25 younger adults (19–40 years) and 25 older adults (60–80 years) on their ability to match cross-modal congruent and incongruent emotional stimuli. The second study looked at performance of 20 younger (19–40) and 20 older adults (60–80) on explicit emotion identification when information was presented congruently in faces and voices or only in faces or in voices. In Study 1, older adults performed as well as younger adults on tasks in which congruent auditory and visual emotional information were presented concurrently, but there were age-related differences in matching incongruent cross-modal information. Results from Study 2 indicated that though older adults were impaired at identifying emotions from 1 modality (faces or voices alone), they benefited from congruent multisensory information as age differences were eliminated. The findings are discussed in relation to social, emotional, and cognitive changes with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-differential motivational consequences of optimization versus compensation focus in younger and older adults.

Four studies investigated age-related differences in goal focus in younger and older adults. Studies 1 and 2 confirmed the hypothesis that younger adults are more persistent when the same sensorimotor task offers possibility for optimizing performance than when the task requires counteracting a loss in performance (compensation). In contrast, older adults were more persistent in the compensation than in the optimization condition. Study 3 showed that the age-differential effects of goal focus on persistence were not simply due to perceiving the 2 conditions as easy versus difficult. Study 4 ruled out that the age differences were due to differences in the 2 tasks themselves. Taken together, the studies underscore the importance of situating motivational research into a life span context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related differences and similarities in dual-task interference.

Differences between younger adults (mean age, 20.7 years) and older adults (mean age, 72.7 years) in dual-task performance were examined in 7 experiments in which the overlap between 2 simple tasks was systematically varied. The results were better fit by a task-switching model in which age was assumed to produce generalized slowing than by a shared-capacity model in which age was assumed to reduce processing resources. The functional architecture of task processing appears the same in younger and older adults. There was no evidence for a specific impairment in the ability of older adults to manage simultaneous tasks. There was evidence for both input and output interference, which may be greater in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and attentional guidance during visual search: Functional neuroanatomy by positron emission tomography.

Positron emission tomography (PET) was used to examine adult age differences in neural activation during visual search. Target detection was less accurate for older adults than for younger adults, but both age groups were successful in using color to guide attention to a subset of display items. Increasing perceptual difficulty led to greater activation of occipitotemporal cortex for younger adults than for older adults, apparently as the result of older adults maintaining higher levels of activation within the easier task conditions. The results suggest that compensation for age-related decline in the efficiency of occipitotemporal cortical functioning was implemented by changes in the relative level of activation within this visual processing pathway, rather than by the recruitment of other cortical regions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is the dissociability of working memory systems for name identity, visual-object identity, and spatial location maintained in old age?

The dissociability of working memory for name identity (verbal information), visual objects, and spatial location was explored in 3 experiments. Consistent with previous results, the 3 working memory systems were dissociable in younger adults. Both younger and older adults showed involvement of name identity in an object identity task, and older adults showed this involvement in a spatial memory task. Results were interpreted as showing that the systems are generally separable but that involvement of 1 with another is possible and more likely in older adults. A 4th, correlational study showed that there is generalized decline in working memory systems in old age, with the age differences in memory mediated to a moderate extent by age-related differences in speed of processing. It was speculated that the specific, possibly strategic changes are independent of and take place against a backdrop of generalized loss of nervous system integrity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential age-related processing limitations in recall and recognition tasks.

The degree to which processing resources are responsible for age differences in performance on recall and recognition tasks was examined in this study. To examine this, a secondary task incorporating a memory component (digit preloads) was implemented during retrieval. Results revealed that older adults, relative to younger adults, exhibited greater decrements in secondary task performance as the difficulty of the secondary task increased. These age differences were greater in the recall task than in the recognition task. Hierarchical regression analyses indicated that speed accounted for the largest proportion of age-related variance in the recall task while both speed and working memory contributed to much of the secondary task variance. Results confirm the hypothesis that recall requires greater processing capacity than recognition and that older adults have greater processing-capacity limitations than younger adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Training effects on dual-task performance: Are there age-related differences in plasticity of attentional control?

A number of studies have suggested that attentional control skills required to perform 2 tasks concurrently become impaired with age (A. A. Hartley, 1992; J. M. McDowd & R. J. Shaw, 2000). A. A. Hartley (2001) recently observed that the age-related differences in dual-task performance were larger when the 2 tasks required similar motor responses. The present study examined the extent to which age-related deficits in dual-task performance or time sharing--in particular, dual-task performance of 2 discrimination tasks with similar motor requirements--can be moderated by training. The results indicate that, even when the 2 tasks required similar motor responses, both older and younger adults could learn to perform the tasks faster and more accurately. Moreover, the improvement in performance generalized to new task combinations involving new stimuli. Therefore, it appears that training can substantially improve dual-task processing skills in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A demonstration of dual-task performance without interference in some older adults.

Highly efficient dual-task processing is demonstrated when reaction time to each of two tasks does not differ between the dual-task situation and the single-task situation. This has been demonstrated reliably in younger adults; nevertheless, the two extant studies of extensive dual-task training did not find evidence for it in any elderly adult. The origins of age-related differences after training were explored in a study in which the stimuli for the two tasks were perfectly redundant although two distinct responses were required. The dual-task situation thus greatly reduced the demands of stimulus categorization while still requiring two response selections and two response executions. After only limited training 8 of 8 younger adults and 5 of 8 older adults showed performance consistent with highly efficient processing. Three older adults failed to show this even after 12 training sessions. The results implicate stimulus categorization more than response selection as an important locus of inefficient dual-task processing, particularly for older adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The attentional demands of encoding and retrieval in younger and older adults: 2. Evidence from secondary task reaction time distributions.

Three studies examined the effects of encoding or retrieval on properties of secondary task reaction time (RT) distributions in younger and older adults. Relative to full attention conditions, encoding and retrieval increased secondary task RT medians and standard deviations more for older adults than for younger adults, and the age-related RT increase was most pronounced among the slowest RTs. Hierarchical regression analyses revealed two age-related mechanisms underlying these effects, which were interpreted as cognitive slowing and reductions in attentional resources. Cognitive slowing affects the entire RT distribution regardless of the memory task. By contrast, reduced attentional resources result in very long RTs, especially when the tasks require self-initiated encoding or retrieval operations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of relational and item-specific information in remembering by older and younger adults.

The applicability to older adults of predictions from the integrated memory model, that optimal memory results from concurrent availability of relational and item-specific information, was assessed. In Experiment 1, older adults (M?=?69 years) encoded related or unrelated words using rating, sorting, or both tasks. Using both tasks produced better recall than either separate task. Rating facilitated recall for related items, but sorting did not facilitate unrelated items. In Experiment 2, younger (M?=?20) and older (M?=?74) adults sorted or rated lists comprising categories of varying sizes. Young adults' free recall conformed to predictions, but older adults again showed facilitation mainly from rating larger categories. The stronger effects for younger adults imply that specific combinations of encoding and retrieval manipulations and materials must be considered in predicting older adults' performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Handwriting performance in younger and older adults: Age, familiarity, and practice effects.

The main goals of 2 experiments on the aging of handwriting skills were to investigate (1) age differences in speed of handwriting performance, (2) effects of task familiarity on age differences in performance, and (3) effects of practice on age differences in performance. Younger adults performed reliably faster than older adults on all tasks. An Age?×?Familiarity interaction in both experiments indicated that age differences were magnified for unfamiliar but attenuated for familiar tasks. In the 2nd experiment, an Age?×?Trial interaction revealed that older adults improved at a faster rate than younger adults. Regressions with initial trial data indicated that the older were slower than the younger adults by a factor of about 1.6. With practice, however, this slowing factor was only 1.02. Results suggest that familiarity and practice play a role in speed of handwriting. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age-related differences in lexical access, spreading activation, and simple pronunciation.

An experiment was conducted to address age-related differences in lexical access, spreading activation, and pronunciation. Both young and older adults participated in a delayed pronunciation task to trace the time course of lexical access and a semantic priming task to trace the time course of spreading activation. In the delayed pronunciation task, subjects were presented a word and then, after varying delays, were presented a cue to pronounce the word aloud. Older adults benefited considerably more from the preexposure to the word than did the younger adults, suggesting an age-related difference in lexical access time. In the semantic priming pronunciation task, semantic relatedness (related vs. neutral), strength of the relationship (high vs. low), and prime–target stimulus onset asynchrony (200 ms, 350 ms, 500 ms, 650 ms, and 800 ms) were factorially crossed with age to investigate age-related differences in the buildup of semantic activation across time. The results from this task indicated that the activation pattern of the older adults closely mimicked that of the younger adults. Finally, the results of both tasks indicated that older adults were slower at both their onset to pronounce and their actual production durations (i.e., from onset to offset) in the pronunciation task. The results were interpreted as suggesting that input and output processes are slowed with age, but that the basic retrieval mechanism of spreading activation is spared by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related differences in recognition memory: Effects of materials and context change.

The study explored age-related differences in the effects of context change on recognition memory by presenting object names (Expt. 1A) or their pictures (Expt. 1B) on background scenes. Participants later attempted to recognize previously presented items on background scenes that were original, switched, blank, or new. Older adults recognized fewer word stimuli than did younger adults, and context effects were larger for older adults. With pictures, however, the age-related decrement was eliminated and context effects were reduced. The beneficial effect of context reinstatement in older adults occurs despite the finding that they are less able to recall or recognize such contexts (Experiment 2). Older adults can use context information in recognition memory at least as efficiently as younger adults when suitable materials and conditions are provided. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Inhibition of return and visuospatial attention in healthy older adults and individuals with dementia of the Alzheimer type.

Covert orienting of visuospatial attention in response to peripherally presented cues was assessed in healthy younger and older adults and those with dementia of the Alzheimer type (DAT) during a simple detection task. The results yield both an age-related increase (Experiments 1 and 2) and a DAT-related increase (Experiment 2) in the facilitatory effect of a single peripheral cue on detection. By contrast, equivalent inhibition of return (i.e., a slowing of target detection at previously cued locations) was observed for all 3 groups when a 2nd cue was presented at central fixation. Results suggest that both healthy older adults and individuals with DAT experience changes in the posterior attention system thought to subserve visuospatial attention. Results also suggest limitations on the generality of inhibitory deficits in healthy aging and DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)