Conceptualization of task boundaries preserves implicit sequence learning under dual-task conditions

Implicit learning in the serial reaction time (SRT) task is sometimes disrupted by the presence of a secondary distractor task (e.g., Schumacher & Schwarb Journal of Experimental Psychology: General 138:270–290, 2009) and at other times is not (e.g., Cohen, Ivry, & Keele Journal of Experimental Psychology: Learning, Memory, and Cognition 16:17–30, 1990). In the present study, we used an instructional manipulation to investigate how participants’ conceptualizations of the task affect sequence learning under dual-task conditions. Two experimental groups differed only in terms of the instructions and presequence training. One group was instructed that they were completing two separate tasks, whereas the other group was instructed that they were performing a single, integrated task. The separate group showed sequence learning, while the integrated group did not. These findings suggest that the conceptualization of task boundaries affects the availability of the sequential information necessary for implicit learning.     

Updating misconceptions: Effects of age and confidence

Young adults are more likely to correct an initial higher confidence error than a lower confidence error (Butterfield & Metcalfe, 2001). This hypercorrection effect has never been investigated among older adults, although features of the standard paradigm (free recall, metacognitive judgments) and prior evidence of age-related error resolution deficits (see Clare & Jones, 2008) suggest that they may not show this effect. In Study 1, we used free recall and a 7-point confidence scale; in Study 2, we used multiple-choice questions, and participants indicated how many alternatives they had narrowed their options down to prior to answering. In both studies, younger and older adults showed a hypercorrection effect, and this effect was equivalent between groups in Study 2 when free recall and explicit confidence ratings were not required. These results are consistent with our previous work (Cyr & Anderson, 2012) showing that older adults can successfully resolve learning errors when the learning context provides sufficient support.     

Irrelevant sensory stimuli interfere with working memory storage: Evidence from a computational model of prefrontal neurons

The encoding of irrelevant stimuli into the memory store has previously been suggested as a mechanism of interference in working memory (e.g., Lange & Oberauer, Memory, 13, 333–339, 2005; Nairne, Memory & Cognition, 18, 251–269, 1990). Recently, Bancroft and Servos (Experimental Brain Research, 208, 529–532, 2011) used a tactile working memory task to provide experimental evidence that irrelevant stimuli were, in fact, encoded into working memory. In the present study, we replicated Bancroft and Servos’s experimental findings using a biologically based computational model of prefrontal neurons, providing a neurocomputational model of overwriting in working memory. Furthermore, our modeling results show that inhibition acts to protect the contents of working memory, and they suggest a need for further experimental research into the capacity of vibrotactile working memory.     

Interactive effects in transfer-appropriate processing for event-based prospective memory: The roles of effort, ongoing task, and PM cue properties

Past studies (e.g., Marsh, Hicks, & Cook Journal of Experimental Psychology: Learning, Memory, and Cognition 31:68–75, 2005; Meiser & Schult European Journal of Cognitive Psychology 20:290–311, 2008) have shown that transfer-appropriate processing (TAP) effects in event-based prospective memory (PM) depend on the effort directed toward the ongoing task. In the present study, we addressed mixed findings from these studies and examined monitoring in TAP and transfer-inappropriate processing (TIP) conditions. In two experiments, a semantic or orthographic ongoing task was paired with a PM cue that either was matched in processing (TAP) or did not match in processing (TIP). Within each condition, effort was varied across trials. The results indicated that PM accuracy was higher in TAP than in TIP conditions, regardless of effort condition, supporting the findings reported by Meiser and Schult. Ex-Gaussian functions were fit to the mean reaction times (cf. Brewer Journal of Psychology 219:117–124, 2011) in order to examine monitoring across conditions. The analysis of distributional skew (τ parameter) showed sensitivity to ongoing task instructions and properties of the PM cues. These results support Meiser and Schult’s suggestion that TIP conditions require more attentional processing, and they also afford novel discussion on the interactive effects of ongoing task condition, PM cue properties, and manipulations of effort.     

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.     

A test of the survival processing advantage in implicit and explicit memory tests

The present study was designed to investigate the survival processing effect (Nairne, Thompson, & Pandeirada, Journal of Experimental Psychology: Learning, Memory, and Cognition, 33, 263–273, 2007) in cued implicit and explicit memory tests. The survival effect has been well established in explicit free recall and recognition tests, but has not been evident in implicit memory tests or in cued explicit tests. In Experiment 1 of the present study, we tested implicit and explicit memory for words studied in survival, moving, or pleasantness contexts in stem completion tests. In Experiment 2, we further tested these effects in implicit and explicit category production tests. Across the two experiments, with four separate memory tasks that included a total of 525 subjects, no survival processing advantage was found, replicating the results from implicit tests reported by Tse and Altarriba (Memory & Cognition, 38, 1110–1121, 2010). Thus, although the survival effect appears to be quite robust in free recall and recognition tests, it has not been replicated in cued implicit and explicit memory tests. The similar results found for the implicit and explicit tests in the present study do not support encoding elaboration explanations of the survival processing effect.     

When disfluency is—and is not—a desirable difficulty: The influence of typeface clarity on metacognitive judgments and memory

There are many instances in which perceptual disfluency leads to improved memory performance, a phenomenon often referred to as the perceptual-interference effect (e.g., Diemand-Yauman, Oppenheimer, & Vaughn (Cognition 118:111–115, 2010); Nairne (Journal of Experimental Psychology: Learning, Memory, and Cognition 14:248–255, 1988)). In some situations, however, perceptual disfluency does not affect memory (Rhodes & Castel (Journal of Experimental Psychology: General 137:615–625, 2008)), or even impairs memory (Glass, (Psychology and Aging 22:233–238, 2007)). Because of the uncertain effects of perceptual disfluency, it is important to establish when disfluency is a “desirable difficulty” (Bjork, 1994) and when it is not, and the degree to which people’s judgments of learning (JOLs) reflect the consequences of processing disfluent information. In five experiments, our participants saw multiple lists of blurred and clear words and gave JOLs after each word. The JOLs were consistently higher for the perceptually fluent items in within-subjects designs, which accurately predicted the pattern of recall performance when the presentation time was short (Exps. 1a and 2a). When the final test was recognition or when the presentation time was long, however, we found no difference in recall for clear and blurred words, although JOLs continued to be higher for clear words (Exps. 2b and 3). When fluency was manipulated between subjects, neither JOLs nor recall varied between formats (Exp. 1b). This study suggests a boundary condition for the desirable difficulty of perceptual disfluency and indicates that a visual distortion, such as blurring a word, may not always induce the deeper processing necessary to create a perceptual-interference effect.     

Correcting the correction of conditional recency slopes

Farrell (Journal of Experimental Psychology: Learning, Memory, and Cognition, 36, 324–347, 2010) presented some analyses of free recall data that suggest that recency items initially become more accessible as recall progresses, in contrast to the assumptions of temporal drift models. Moran and Goshen-Gottstein (2013) present some challenges to Farrell’s (2010) analyses of the change in conditional recency across output position in free recall. Simulations using a very basic free recall model that controls conditional recency across recall show that Farrell’s (2010) analyses are not substantially biased, while the procedure proposed by Moran and Goshen-Gottstein introduces a substantial underestimation of the true slopes. The null slopes observed in immediate recall by Moran and Goshen-Gottstein are not informative of the true slopes characterizing the data. Accordingly, Farrell’s (2010) results continue to present a challenge to temporal drift models.     

Dual n-back training increases the capacity of the focus of attention

Working memory (WM) training has been reported to benefit abilities as diverse as fluid intelligence (Jaeggi et al., Proceedings of the National Academy of Sciences of the United States of America, 105:6829–6833, 2008) and reading comprehension (Chein & Morrison, Psychonomic Bulletin & Review, 17:193–199, 2010), but transfer is not always observed (for reviews, see Morrison & Chein, Psychonomics Bulletin & Review, 18:46–60, 2011; Shipstead et al., Psychological Bulletin, 138:628–654, 2012). In contrast, recent WM training studies have consistently reported improvement on the trained tasks. The basis for these training benefits has received little attention, however, and it is not known which WM components and/or processes are being improved. Therefore, the goal of the present study was to investigate five possible mechanisms underlying the effects of adaptive dual n-back training on working memory (i.e., improvements in executive attention, updating, and focus switching, as well as increases in the capacity of the focus of attention and short-term memory). In addition to a no-contact control group, the present study also included an active control group whose members received nonadaptive training on the same task. All three groups showed significant improvements on the n-back task from pretest to posttest, but adaptive training produced larger improvements than did nonadaptive training, which in turn produced larger improvements than simply retesting. Adaptive, but not nonadaptive, training also resulted in improvements on an untrained running span task that measured the capacity of the focus of attention. No other differential improvements were observed, suggesting that increases in the capacity of the focus of attention underlie the benefits of adaptive dual n-back training.     

Improving memory after environmental context change: A strategy of “preinstatement”

A change in environmental context between study and test can produce detrimental effects on memory. For instance, when a change in the environment occurs after an event, memory for the event declines. However, the negative effects of context change can be eliminated when participants are provided with contextual cues. Here, we report that, as predicted by the Lehman–Malmberg model (Lehman & Malmberg Journal of Experimental Psychology: Learning, Memory, and Cognition 35(4):970, 2009, Psychological Review, 2012), participants can overcome a change in the environment by recalling the future test environment while studying, a strategy referred to as preinstatement.     

Aging and the psychological refractory period: task-coordination strategies in young and old adults

The apparently deleterious effect of aging on dual-task performance is well established, but there is little agreement about the source of this effect. Studies of the psychological refractory period (PRP) indicate that young adults can flexibly control dual-task performance through task-coordination strategies. Thus, the performance of older adults might differ from young adults because older adults use different task-coordination strategies. To test this hypothesis, the executive-process interactive control (EPIC) architecture was applied to quantify the reaction time data from two PRP experiments conducted with young (age 18-26) and older (age 60-70) adults. The results show that participants' ability to coordinate the processing of two tasks did not decline with age. However, dual-task time costs were greater in the older adults. Three sources for this increase were found: generalized slowing, process-specific slowing, and the use of more cautious task-coordination strategies by the older adults.     

Effects of extensive dual-task practice on processing stages in simultaneous choice tasks

Schumacher et al. Psychological Science 12:101–108, (2001) demonstrated the elimination of most dual-task costs (“perfect time-sharing”) after extensive dual-task practice of a visual and an auditory task in combination. For the present research, we used a transfer methodology to examine this practice effect in more detail, asking what task-processing stages were sped up by this dual-task practice. Such research will be essential to specify mechanisms associated with the practice-related elimination of dual-task costs. In three experiments, we introduced postpractice transfer probes focusing on the perception, central response-selection, and final motor-response stages. The results indicated that the major change achieved by dual-task practice was a speed-up in the central response-selection stages of both tasks. Additionally, perceptual-stage shortening of the auditory task was found to contribute to the improvements in time-sharing. For a better understanding of such time-sharing, we discuss the contributions of the present findings in relation to models of practiced dual-task performance.     

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.     

Age-neutrality of the NEO-PI-R: Potential Differential Item Functioning in Older Versus Younger Adults

Geriatric researchers and clinicians often have to deal with a lack of valid personality measures for older age groups (e.g., Mroczek, Hurt, & Berman, 1999; Zweig 2008), which hampers a reliable assessment of personality in later life. An age-neutral measurement system is one of the basic conditions for an accurate personality assessment across the lifespan, both longitudinally and cross-sectionally. In the present study, we empirically investigate the age-neutrality of one of the most widely used personality measures (i.e., the NEO PI-R (Costa & McCrae, 1992)), by examining potential Differential Item Functioning (DIF). Overall, results indicate that the vast majority (92.9?% at domain-level and 95?% at facet-level) of the NEO PI-R items was similarly endorsed by younger and older age groups with the same position on the personality trait of interest, corroborating the NEO PI-R??s age neutrality. However, Differential Test Functioning (DTF) analyses revealed large DTF for Extraversion, and facet A6 (Tender-Mindedness). Results are discussed in terms of their implications for using the current format of the NEO PI-R in older aged samples.     

Mutual information, perceptual independence, and holistic face perception

The concept of perceptual independence is ubiquitous in psychology. It addresses the question of whether two (or more) dimensions are perceived independently. Several authors have proposed perceptual independence (or its lack thereof) as a viable measure of holistic face perception (Loftus, Oberg, & Dillon, Psychological Review 111:835–863, 2004; Wenger & Ingvalson, Learning, Memory, and Cognition 28:872–892, 2002). According to this notion, the processing of facial features occurs in an interactive manner. Here, I examine this idea from the perspective of two theories of perceptual independence: the multivariate uncertainty analysis (MUA; Garner & Morton, Definitions, models, and experimental paradigms. Psychological Bulletin 72:233–259, 1969), and the general recognition theory (GRT; Ashby & Townsend, Psychological Review 93:154–179, 1986). The goals of the study were to (1) introduce the MUA, (2) examine various possible relations between MUA and GRT using numerical simulations, and (3) apply the MUA to two consensual markers of holistic face perception^—recognition of facial features (Farah, Wilson, Drain, & Tanaka, Psychological Review 105:482–498, 1998) and the composite face effect (Young, Hellawell, & Hay, Perception 16:747–759, 1987). The results suggest that facial holism is generated by violations of several types of perceptual independence. They highlight the important theoretical role played by converging operations in the study of holistic face perception.     

Age- and practice-related influences on dual-task costs and compensation mechanisms under optimal conditions of dual-task performance

Impaired dual-task performance in younger and older adults can be improved with practice. Optimal conditions even allow for a (near) elimination of this impairment in younger adults. However, practice effects under these conditions in older adults are unknown. Further, it is open, how changed task scheduling and/ or the acquisition of task coordination skills affect the temporal overlap of two tasks in different age groups; this overlap indicate the involvement of these practice-related mechanisms to compensate for impaired dual-task performance. In a dual-task situation of Schumacher et al. (2001 , Psychological Science, 12, 230) including optimal conditions for dual-task performance, both younger and older adults were able to achieve an improvement in dual-task performance with 8 practice sessions to the same degree. The temporal task overlap changed similarly in both age groups during these sessions demonstrating a similar degree of the involvement of compensation mechanisms in younger and older adults. At the end of practice, however, we showed that older adults do not achieve the same optimized dual-task performance level of younger adults.     

Age-differential effects on updating cue information: Evidence from event-related potentials

Recent models on cognitive aging consider the ability to maintain and update context information to be a key source of age-related impairments in various cognitive tasks (Braver & Barch in Neuroscience & Biobehavioral Reviews, 26: 809–817, 2002). Context updating has been investigated with a modified AX-continuous-performance task by comparing performance and brain activity between context-dependent trials (i.e., correct responses require updating of the preceding cue information) and context-independent trials (i.e., correct responses are independent of cue information). We used an event-related potential (ERP) approach to identify sources of age differences in context processing in the early and late processing of cue information. Our behavioral data showed longer latencies and higher error rates on context-dependent than on context-independent trials for older than for younger adults, suggesting age-related impairments in context updating. The ERP data revealed larger P3b amplitudes for context-dependent than for context-independent trials only in younger adults. In contrast, in older adults, P3b amplitudes were more evenly distributed across the scalp and did not differ between context conditions. Interestingly, older but not younger adults were sensitive to changes of cue identity, as indicated by larger P3b amplitudes on cue-change than on cue-repeat trials, irrespective of the actual context condition. We also found a larger CNV on context-dependent than on context-independent trials, reflecting active maintenance of context information and response preparation. The age-differential effects in the P3b suggest that both younger and older adults were engaged in updating task-relevant information, but relied on different information: Whereas younger participants indeed relied on context cues to update and reconfigure the task settings, older adults relied on changes in cue identity, irrespective of context information.     

Margaret R. Miles’ Augustine and the Fundamentalist’s Daughter: An Eriksonian Perspective

My perspective on Margaret R. Miles’s Augustine and the Fundamentalist’s Daughter is informed by Erik H. Erikson’s life cycle model (Erikson 1950, 1959, 1963, 1964, 1968a, b, 1982; Erikson and Erikson 1997) and, more specifically, by my relocation of his life stages and their accompanying human strengths (Erikson 1964) according to decades (Capps 2008). I interpret Miles’s account of her life from birth to age forty as revealing the selves that comprise the composite Self (Erikson 1968a) that come into their own during the first four decades of the life cycle, i.e., the hopeful, willing, purposeful, and competent selves     

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.     

Dual-task costs of texting while walking forward and backward are greater for older adults than younger adults

Cognitive-motor dual-tasking involves concurrent performance of two tasks with distinct cognitive and motor demands and is associated with increased fall risk. In this hypothesis-driven study, younger (18–30 years, n = 24) and older (60–75 years, n = 26) adults completed six walking tasks in triplicate. Participants walked forward and backward along a GAITRite mat, in isolation or while performing a verbal fluency task. Verbal fluency tasks involved verbally listing or typing on a smartphone as many words as possible within a given category (e.g., clothes). Using repeated measures MANOVA models, we examined how age, method of fluency task (verbal or texting), and direction of walking altered dual-task performance. Given that tasks like texting and backward walking require greater cognitive resources than verbal and forward walking tasks, respectively, we hypothesized older adults would show higher dual-task costs (DTCs) than younger adults across different task types and walking directions, with degree of impairment more apparent in texting dual-task trials compared to verbal dual-task trials. We also hypothesized that both age groups would have greater DTCs while walking backward than while walking forward, regardless of task.Independent of age group, velocity and stride length were reduced for texting compared to the verbal task during both forward and backward walking; cadence and velocity were reduced while walking forward compared to walking backward for the texting task; and stride length was reduced for forward walking compared to backward walking during the verbal task. Younger adults performed better than older adults on all tasks with the most pronounced differences seen in velocity and stride length during forward-texting and backward-texting. Interaction effects for velocity and stride length while walking forward indicated younger adults performed better than older adults for the texting task but similarly during the verbal task. An interaction for cadence during the verbal task indicated younger adults performed better than older adults while walking backward but similarly while walking forward.In summary, older adults experienced greater gait decrement for all dual-task conditions. The greater declines in velocity and stride length in combination with cadence being stable suggest reductions in velocity during texting were due to shorter strides rather than a reduced rate of stepping. Contrary to our hypotheses, we found greater DTCs while walking forward rather than backward, which may be due to reduced gait performance during single-task backward walking; thus, further decrements with dual-tasking are unlikely. These findings underscore the need for further research investigating fall risk potential associated with texting and walking among aging populations and how interventions targeting stride length during dual-task circumstances may improve performance.