Age Equivalence in Switch Costs for Prosaccade and Antisaccade Tasks

Does age-related hearing loss deteriorate attentional resources?

Recent work suggests that age-related hearing loss (HL) is a possible risk factor for cognitive decline in older adults. Resulting poor speech recognition negatively impacts cognitive, social and emotional functioning and may relate to dementia. However, little is known about the consequences of hearing loss on other non-linguistic domains of cognition. The aim of this study was to investigate the role of HL on covert orienting of attention, selective attention and executive control. We compared older adults with and without mild to moderate hearing loss (26-60 dB) performing (1) a spatial cueing task with uninformative central cues (social vs. nonsocial cues), (2) a flanker task and (3) a neuropsychological assessment of attention. The results showed that overall response times and flanker interference effects were comparable across groups. However, in spatial cueing of attention using social and nonsocial cues, hearing impaired individuals were characterized by reduced validity effects, though no additional group differences were found between social and nonsocial cues. Hearing impaired individuals also demonstrated diminished performance on the Montreal Cognitive Assessment (MoCA) and on tasks requiring divided attention and flexibility. This work indicates that while response speed and response inhibition appear to be preserved following mild-to-moderate acquired hearing loss, orienting of attention, divided attention and the ability to flexibly allocate attentional resources are more deteriorated in older adults with HL. This work suggests that hearing loss might exacerbate the detrimental influences of aging on visual attention.

Age Differences in the Subcomponents of Executive Functioning

OBJECTIVES

Across the life span, deficits in executive functioning (EF) are associated with poor behavioral control and failure to achieve goals. Though EF is often discussed as one broad construct, a prominent model of EF suggests that it is composed of three subdomains: inhibition, set shifting, and updating. These subdomains are seen in both younger (YA) and older adults (OA), with performance deficits across subdomains in OA. Therefore, our goal was to investigate whether subdomains of EF might be differentially affected by age, and how these differences may relate to broader global age differences in EF.

METHODS

To assess these age differences, we conducted a meta-analysis at multiple levels, including task level, subdomain level, and of global EF. Based on previous work, we hypothesized that there would be overall differences in EF in OA.

RESULTS

Using 1,268 effect sizes from 401 articles, we found overall differences in EF with age. Results suggested that differences in performance are not uniform, such that variability in age effects emerged at the task level, and updating was not as affected by age as other subdomains.

DISCUSSION

These findings advance our understanding of age differences in EF, and stand to inform early detection of EF decline.

Aging Effects and Test-Retest Reliability of Inhibitory Control for Saccadic Eye Movements

Neuropsychological studies indicate that healthy aging is associated with a decline of inhibitory control of attentional and behavioral systems. A widely accepted measure of inhibitory control is the antisaccade task that requires both the inhibition of a reflexive saccadic response toward a visual target and the initiation of a voluntary eye movement in the opposite direction. To better understand the nature of age-related differences in inhibitory control, we evaluated antisaccade task performance in 78 younger (20-35 years) and 78 older (60-80 years) participants. In order to provide reliable estimates of inhibitory control for individual subjects, we investigated test-retest reliability of the reaction time, error rate, saccadic gain, and peak saccadic velocity and further estimated latent, not directly observable processed contributing to changes in the antisaccade task execution. The intraclass correlation coefficients (ICCs) for an older group of participants emerged as good to excellent for most of our antisaccade task measures. Furthermore, using Bayesian multivariate models, we inspected age-related differences in the performances of healthy younger and older participants. The older group demonstrated higher error rates, longer reaction times, significantly more inhibition failures, and late prosaccades as compared with young adults. The consequently lower ability of older adults to voluntarily inhibit saccadic responses has been interpreted as an indicator of age-related inhibitory control decline. Additionally, we performed a Bayesian model comparison of used computational models and concluded that the Stochastic Early Reaction, Inhibition and Late Action (SERIA) model explains our data better than PRO-Stop-Antisaccade (PROSA) that does not incorporate a late decision process.

Switch costs in inhibitory control and voluntary behaviour: A computational study of the antisaccade task

An integral aspect of human cognition is the ability to inhibit stimulus-driven, habitual responses, in favour of complex, voluntary actions. In addition, humans can also alternate between different tasks. This comes at the cost of degraded performance when compared to repeating the same task, a phenomenon called the "task-switch cost." While task switching and inhibitory control have been studied extensively, the interaction between them has received relatively little attention. Here, we used the SERIA model, a computational model of antisaccade behaviour, to draw a bridge between them. We investigated task switching in two versions of the mixed antisaccade task, in which participants are cued to saccade either in the same or in the opposite direction to a peripheral stimulus. SERIA revealed that stopping a habitual action leads to increased inhibitory control that persists onto the next trial, independently of the upcoming trial type. Moreover, switching between tasks induces slower and less accurate voluntary responses compared to repeat trials. However, this only occurs when participants lack the time to prepare the correct response. Altogether, SERIA demonstrates that there is a reconfiguration cost associated with switching between voluntary actions. In addition, the enhanced inhibition that follows antisaccade but not prosaccade trials explains asymmetric switch costs. In conclusion, SERIA offers a novel model of task switching that unifies previous theoretical accounts by distinguishing between inhibitory control and voluntary action generation and could help explain similar phenomena in paradigms beyond the antisaccade task.

Associations of Cognitive Function with BMI, Body Fat Mass and Visceral Fat in Young Adulthood

Background and objectives: Existing studies concerning the associations of cognitive function with adiposity in young adults are sparse. The purpose of the study was to examine the associations of adiposity with cognitive control in young adults. Materials and Methods: Participants were 213 young adults (98 women and 115 men). Cognitive control was measured using a modified task-switching paradigm. Anthropometrics were measured by standardized procedures. Body fat mass and visceral fat area were measured by bioelectrical impedance analysis. Results: The results showed that increased body mass index (BMI, p = 0.02), body fat percentage (p = 0.02), and visceral fat area (p = 0.01) were significantly correlated with larger global switch costs of accuracy in women. In men, high levels of body fat percentage (p = 0.01) and visceral fat area (p = 0.03) were significantly correlated with larger local switch costs of reaction time. Conclusions: The results indicated that elevated adiposity was associated with worse performance on measures of cognitive control in young adults.

Associations Between Objectively Measured Physical Activity and Executive Functioning in Young Adults

Associations between daily physical activity (PA) and executive functioning have rarely been investigated among young adults. This study examined these associations among 162 university students (74 females and 88 males; mean age = 19.0, SD = 1.1 years). We measured PA objectively, using hip-mounted accelerometers, and assessed executive functioning in a task-switching paradigm. Anthropometrics measurements were gathered using standardized procedures. Through linear regression modeling, we found moderate-to-vigorous physical activity (β = −0.19, 95% CI = [−0.35, −0.03], p = .02) and light physical activity (β = −0.17, 95% CI = [−0.34, −0.01], p = .04) to be associated with smaller global reaction time switch costs. Total PA was not associated with task-switching performance, and there were no statistically significant associations between PA indicators and local switch costs. As both moderate-to-vigorous and light physical activities were associated with better executive function in young adults, there can be important cognitive benefits to remaining physically active.

Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

BACKGROUND/STUDY CONTEXT

Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the "common cause" hypothesis of Lindenberger & Baltes, 1994, Psychology and Aging, 9, 339-355). McGowan, Patterson, and Jordan (2013, Experimental Aging Research, 39, 70-79) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (La Fleur and Salthouse, 2014, Psychonomic Bulletin & Review, 21, 1202-1208) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic.

METHODS

Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better).

RESULTS

As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria.

CONCLUSION

The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance-thereby replicating La Fleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g., contrast sensitivity, luminance) affect age differences in cognitive functioning.

Age-related differences in task switching and task preparation: Exploring the role of task-set competition

The present study focused on the role of task preparation in age-related task-switching deficits. In Experiment 1, we assessed the preparatory reduction of alternation costs (i.e., alternating-task conditions vs. single-task conditions) in twenty-two older adults (65-78years) and 22 young adults (20-28years) by varying the response-stimulus interval (RSI) in a task-switching paradigm with a predictable task sequence and univalent stimuli. In Experiment 2, in which new groups of 22 older adults (65-78years) and 22 young adults (18-24years) took part, we replicated Experiment 1 with bivalent stimuli, which were associated with both tasks and thus increased task-set competition. Whereas in Experiment 1, in which we used univalent stimuli, there were no age-related differences in the preparatory reduction of alternation costs, the data showed impaired task preparation in old age with bivalent stimuli in Experiment 2. These data support the notion that task-preparation deficits in old age occur particularly in situations of increased task-set competition.

Long-Term Maintenance of Inhibition Training Effects in Older Adults: 1- and 3-Year Follow-Up

OBJECTIVES

The aim of this study is to examine the long-term maintenance of training benefits in inhibition, as measured with the Stroop task, in older adults over 1- and 3-year periods.

METHODS

Participants from an original 6-session Stroop training study (Wilkinson & Yang, 2012 [Wilkinson, A. J., & Yang, L. (2012). Plasticity of inhibition in older adults: Retest practice and transfer effects. Psychology and Aging, 27, 606-615. doi:10.1037/a0025926]) were invited to come back to the lab to complete a single session of the Stroop task at 2 different time points. Thirty-three older adults returned for the 1-year follow-up session, and 26 of them returned for the 3-year follow-up session.

RESULTS

The results revealed maintenance of the training-induced inhibition gains at both follow-up sessions. Furthermore, performance at the 2 follow-up sessions was better (i.e., reduced Stroop ratio interference score) than baseline level.

DISCUSSION

The findings demonstrate the durability of inhibition training gains in older adults for up to a 3-year period. These results further extend the literature on long-term maintenance of cognitive training benefits in older adults by examining the durability of training effects in inhibition, an important executive function, and by covering a substantial maintenance period (i.e., up to 3 years).

Increased attentional focus modulates eye movements in a mixed antisaccade task for younger and older adults

We examined performance in the antisaccade task for younger and older adults by comparing latencies and errors in what we defined as high attentional focus (mixed antisaccades and prosaccades in the same block) and low attentional focus (antisaccades and prosaccades in separate blocks) conditions. Shorter saccade latencies for correctly executed eye movements were observed for both groups in mixed, compared to blocked, antisaccade tasks, but antisaccade error rates were higher for older participants across both conditions. The results are discussed in relation to the inhibitory hypothesis, the goal neglect theory and attentional control theory.

Aging and task switching: a meta-analysis

A meta-analysis of 26 published articles (with 36 independent participant groups) was conducted to analyze the relationship between task-switching effects and aging. Latency served as the dependent measure. Multilevel modeling was used to test for additive and multiplicative complexity effects in local and global switch costs. Global task switching was found to add 1 or more stages to processing and resulted in a marked age deficit. Local task-switching costs, on the other hand, showed a multiplicative complexity effect but no specific attention-related age deficits. Cueing or switch predictability did not affect age differences.

Switching between gap and overlap pro-saccades: cost or benefit?

Triggering of saccades depends on the task: in the gap task, fixation point switches off and target appears after a gap period; in the overlap task, target appears while fixation point is still on. Saccade latencies are shorter in the gap task, due to fixation disengagement and advanced movement preparation during the gap. The two modes of initiation are also hypothesized to be subtended by different cortical-subcortical circuits. This study tested whether interleaving the two tasks modifies latencies, due to switching between different modes of triggering. Two groups of healthy participants (21-29 vs. 39-55 years) made horizontal and vertical saccades in gap, overlap, and mixed tasks; saccades were recorded with the Eyelink. Both groups showed shorter latencies in the gap task, i.e. a robust gap effect and systematic differences between directions. For young adults, interleaving tasks made the latencies shorter or longer depending on direction, while for middle-age adults, latencies became longer for all directions. Our observations can be explained in the context of models such as that of Brown et al. (Neural Netw 17:471-510, 2004), which proposed that different combinations of frontal eye field (FEF) layers, interacting with cortico-subcortical areas, control saccade triggering in gap and overlap trials. Moreover, we suggest that in early adulthood, the FEF is functioning optimally; frequent changes of activity in the FEF can be beneficial, leading to shorter latencies, at least for some directions. However, for middle-age adults, frequent changes of activity of a less optimally functioning FEF can be time consuming. Studying the alternation of gap and overlap tasks provides a fine tool to explore development, aging and disease.

The role of switching, inhibition and working memory in older adults' performance in the Wisconsin Card Sorting Test

The Wisconsin Card Sorting Test (WCST) is considered a typical executive test. However, several interesting questions are still open as to the specific executive processes underlying this task. In the present study, we explored how local and global switching, inhibition and working memory, assessed through the Number-Letter, the Stop Signal and the Reading Span tasks, relate to older adults' performance in the WCST. Results showed that older adults' performance variability in the number of perseverative errors was predicted by the local switch component of the Number-Letter task. Results also showed age-related differences in inhibition, working memory and global switching, while local switching resulted largely spared in aging. This study provides evidence that switching abilities may contribute to performance of older adults in the WCST. It also provides initial evidence suggesting that switching processes, associated with local switch costs, are involved in performance on the WCST, at least in older adults.

Age-group differences in inhibiting an oculomotor response

Age-group differences were examined in the delayed oculomotor response task, which requires that observers delay the execution of a saccade (eye movement) toward an abrupt-onset visual cue. This task differs from antisaccade and attentional capture in that inhibition causes saccades to be postponed, not redirected. Older adults executed more premature saccades than young adults, but there were no age-group differences in latency or accuracy of saccades executed at the proper time. The results suggest that older adults are less capable of inhibiting a prepotent saccadic response, but that other aspects of visual working memory related to the task are preserved.

Age deficits in the control of prepotent responses: evidence for an inhibitory decline

Older adults have more difficulty than younger adults appropriately directing their behavior when the required response is in competition with a prepotent response. The authors varied the difficulty of inhibiting a prepotent eye movement response by varying the response cue (peripheral onset or central arrow). The response cue manipulation did not affect prosaccade accuracy and latency for either age group and did not affect younger adults' antisaccades. Older adults' antisaccades were slower in the peripheral cue condition than in the central arrow condition. These findings are taken as support for the inhibitory deficit hypothesis of aging (L. Hasher, R. T. Zacks, & C. P. May, 1999).

Effects of associative learning on age differences in task-set switching

Costs of switching between tasks may disappear when subjects are able to learn associations between tasks, stimuli, and responses (cf. Rogers, R. D., & Monsell, S. (1995). Costs of a predictable switch between simple cognitive tasks. Journal of Experimental Psychology: General, 124, 207-231). The first aim of this study was to examine this possibility by manipulating stimulus-set size. We expected that costs of switching between tasks would be strongly reduced under conditions of small stimulus-set sizes (n=4) as compared to large stimulus-set sizes (n=96) with increasing time on task. The second aim was to determine whether younger as well as older adults were able to create associations between task components. As age differences in task switching are often found to be larger when response mappings are incompatible we also investigated interactions with response compatibility. Results of our study indicated that practice effects on switch costs were much more pronounced for small than large stimulus-set sizes, consistent with the view that the strength of associations between task components facilitates task switching. Furthermore, we found that practice benefits on task switching for small stimulus-set sizes were sensitive to age and response compatibility. In contrast to younger adults, who showed a reduction of switch costs for both response mapping conditions, older adults showed a reduction of switch costs only when response mappings were compatible. That is, older adults showed less associative learning when the currently irrelevant task feature had to be suppressed, supporting the view that older adults have primarily problems in separating overlapping task-set representations.

Growing Older Does Not Always Mean Moving Slower: Examining Aging and the Saccadic Motor System

Although humans typically move more slowly as they age, one exception may be the saccadic motor system. To fully determine whether the execution of saccades is affected by age, the authors examined detailed kinematics of vertical and horizontal saccades across a range of saccadic amplitudes (4 degrees, 8 degrees, and 12 degrees). Ten younger and 20 older adults participated in each experiment. Whereas in the 1st experiment, the authors assessed volitionally generated saccades, in the 2nd experiment, they evaluated reflexively generated saccades. The results of those experiments showed that the saccadic motor system is relatively impervious to the effects of aging; in fact, the differences between vertical and horizontal saccades were more evident than were differences between saccades produced by younger and older adults. The authors discuss possible reasons for that relative resistance to aging.

Age and physical activity influences on action monitoring during task switching

Behavioral and neuroelectric indices of action monitoring were compared for 53 high and low physically active older (60-71 years) and younger (18-21 years) adults during a task-switching paradigm in which they performed a task repeatedly or switched between two different tasks. The error-related negativity (ERN) of a response-locked event-related brain potential (ERP) and behavioral measures of response speed and accuracy were measured during the heterogeneous condition (switching randomly between two tasks) of the switch task. Results indicated that older adults exhibited a greater relative slowing in RT during heterogeneous blocks and smaller ERN amplitude compared to younger adults. Additionally, physical activity differences revealed a relatively smaller global switch cost for physically active older adults and decreased ERN amplitude, as well as increased post-error response slowing for older and younger physically active participants, compared to their less physically active counterparts. The findings suggest that both age and physical activity participation influence behavioral and neuroelectric indices of action monitoring and provide further evidence for the beneficial effects of physical activity on executive control.

Task-set switching under cue-based versus memory-based switching conditions in younger and older adults

Adult age differences in task switching and advance preparation were examined by comparing cue-based and memory-based switching conditions. Task switching was assessed by determining two types of costs that occur at the general (mixing costs) and specific (switching costs) level of switching. Advance preparation was investigated by varying the time interval until the next task (short, middle, very long). Results indicated that the implementation of task sets was different for cue-based switching with random task sequences and memory-based switching with predictable task sequences. Switching costs were strongly reduced under cue-based switching conditions, indicating that task-set cues facilitate the retrieval of the next task. Age differences were found for mixing costs and for switching costs only under cue-based conditions in which older adults showed smaller switching costs than younger adults. It is suggested that older adults adopt a less extreme bias between two tasks than younger adults in situations associated with uncertainty. For cue-based switching with random task sequences, older adults are less engaged in a complete reconfiguration of task sets because of the probability of a further task change. Furthermore, the reduction of switching costs was more pronounced for cue- than memory-based switching for short preparation intervals, whereas the reduction of switch costs was more pronounced for memory- than cue-based switching for longer preparation intervals at least for older adults. Together these findings suggest that the implementation of task sets is functionally different for the two types of task-switching conditions.

Age-related deficits in guided search using cues

The ability of young and older adults to engage in guided conjunction search was tested in 2 experiments. In the cued condition, a picture of the target was presented before the search. In the noncued condition, there was no picture of the target. In Experiment 1, the cue was presented for 200 ms; the magnitude of the cuing effect (noncued response time--cued response time) was greater for the young than for the older observers. In Experiment 2 (older observers only), the cue duration was doubled, and older observers had a larger magnitude of cuing effect than found in Experiment 1 but not as large as what would be expected under generalized slowing. The results indicated that older observers had difficulty with interpreting the cue and setting search parameters when the target varied across trials.

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.

Aging and the Strategic Control of the Fixation Offset Effect

A study was conducted to examine potential age-related differences in the strategic control of exogenous and endogenous saccades within the context of the fixation offset effect (FOE; i.e., faster saccades when a fixation point is removed than when it is left on throughout a trial). Subjects were instructed to make rapid saccades either on the basis of a suddenly appearing peripheral visual stimulus (exogenous saccade) or in response to a tone (endogenous saccade). On half of the trials the fixation point was removed simultaneously with the occurrence of the cue stimulus. Subjects' preparatory set was varied by manipulating the proportion of saccades generated to a visual and auditory stimulus within a trial block. Young and old adults both produced FOEs, and the FOEs were strategically modulated by preparatory set. The data are discussed in terms of aging and oculomotor control.