Within-session practice eliminates age differences in cognitive control

ABSTRACT

Previous research employing short-term practice and long-term training have been successful in reducing cognitive control deficits in the elderly. The goal of this study was to examine the effect of practice within session on a demanding cognitive control task. Nineteen older adults and 16 young adults performed 720 trials of a cued version of the Stroop task, in which an instructional cue is presented before each individually presented Stroop stimulus. Statistical analyses focused on the most difficult color-naming condition in task-switching blocks. Overall, participants showed faster reaction times and decreased errors with practice, particularly on incongruent trials. Older adults showed a greater reduction in errors with practice than young adults. Moreover, older adults, but not young adults, showed a reduction in errors and reaction times with practice on incongruent trials. Findings further suggest that practice reduces age-related differences in cognitive control. Improvements in cognitive control functioning has implications for treating functional deficits in older adults.     

The effects of the age of eyewitnesses on the accuracy and suggestibility of their testimony

Previous studies have compared the performance of young adult eyewitnesses with that of children or elderly eyewitnesses, but few studies have allowed direct comparison of the performance of all three age groups. The accuracy and suggestibility of accounts of a video recording of a kidnapping were investigated using an experimental eyewitness paradigm. Subjects were drawn from three age groups: children (aged 7–9 years); young adults (aged 16–18 years) and elderly subjects (aged 60–85 years). Subjects' accuracy in answering non-misleading questions and their susceptibility to misleading information was measured. Both the elderly and child subjects gave fewer correct answers and more incorrect answers to non-misleading questions than did young adults. The elderly subjects gave fewer correct responses but also fewer incorrect responses to non-misleading questions than did child subjects. Children were more suggestible than either elderly or young adults. No significant difference was found in the suggestibility of elderly and young adults. Contrary to the trace strength hypothesis no relationship was found between accuracy of recall and suggestibility. © 1997 John Wiley & Sons, Ltd.     

Search and selection processes in implicit and explicit word-stem completion performance in young, middle-aged, and older adults

In the present investigation, we sought to (1) replicate previous reports of impaired word-stem completion (WSC) priming and cued recall performance in older adults, (2) gain a better understanding of the differential roles of search and selection processes in implicit and explicit WSC, and (3) determine the particular aspects of WSC performance that are influenced by age. Experiment 1 demonstrated that older adults primed and recalled fewer items on a WSC task than middle-aged adults did, who in turn primed and recalled fewer items than young adults did. A series of item analyses indicated that choice of a stem completion is influenced by two independent sources of information: the familiarity of the completion reflected by word frequency and the cue-specific match between the stem and the completion word based on the common pronunciation of the stem. Experiment 2 demonstrated that older adults utilized cue-specific matching to the same degree as young and middle-aged adults. However, the impact of target familiarity changed across the lifespan. Older adults produced and recalled high-frequency targets as well as young adults but produced and recalled fewer low-frequency targets than did young participants. The results are consistent with the view that older adults rely on familiarity to a greater degree than do young adults.     

A pilot study of performance in young and middle-aged adults on verbal recall

The objective was to explore whether middle-aged adults (M age = 48.9 yr.; n = 26) differed on verbal recall from young adults (M age = 26.3 yr.; n = 26). Little data exist on the performance of middle-aged, healthy adults. Groups of young and middle-aged adults recalled words from the Rey Auditory Verbal Learning Test across six trials during a single session. The same 15 words were used for recall in Trials 1-5. Prior to the sixth trial, 15 distractor words were presented. Participants then recalled the original set of 15 words. No significant differences occurred on any of the recall trials. Although the power of this study was low, the effect of age is apparently quite small.     

Altered behavioral and neural responsiveness to counterfactual gains in the elderly

Counterfactual information processing refers to the consideration of events that did not occur in comparison to those actually experienced, in order to determine optimal actions, and can be formulated as computational learning signals, referred to as fictive prediction errors. Decision making and the neural circuitry for counterfactual processing are altered in healthy elderly adults. This experiment investigated age differences in neural systems for decision making with knowledge of counterfactual outcomes. Two groups of healthy adult participants, young (N = 30; ages 19–30 years) and elderly (N = 19; ages 65–80 years), were scanned with fMRI during 240 trials of a strategic sequential investment task in which a particular strategy of differentially weighting counterfactual gains and losses during valuation is associated with more optimal performance. Elderly participants earned significantly less than young adults, differently weighted counterfactual consequences and exploited task knowledge, and exhibited altered activity in a fronto-striatal circuit while making choices, compared to young adults. The degree to which task knowledge was exploited was positively correlated with modulation of neural activity by expected value in the vmPFC for young adults, but not in the elderly. These findings demonstrate that elderly participants’ poor task performance may be related to different counterfactual processing.     

Cognitive addition: strategy choice and speed-of-processing differences in young and elderly adults

Sixty young and 60 elderly adults completed a pencil-and-paper addition test and solved 40 computer-presented simple addition problems. Strategies and problem solution times were recorded on a trial-by-trial basis and were classified in accordance with the distributions of associations model of strategy choices. The elderly group showed a performance advantage on the ability measure and for the developmental maturity of the mix of problem-solving strategies, but the young group showed an advantage for overall solution times. A componential analysis of the overall solution times for memory retrieval trials, however, showed no reliable age difference for rate of retrieving addition facts from long-term memory but did suggest that the elderly adults might have been slower than the younger adults for rate of encoding digits and verbally producing an answer. Overall results are interpreted within the context of the strategy choice model.     

Eye movement correlates of younger and older adults' strategies for complex addition

This study examined performance measures and eye movements associated with complex arithmetic strategies in young and older adults. Participants added pairs of three-digit numbers using two different strategies, under choice and no-choice conditions. Older adults made more errors but were not significantly slower than young adults, and response times and errors showed no interaction between age and the number of carries. Older adults chose strategies less adaptively than young adults. Eye movements were consistent with use of required strategies on no-choice trials and reported strategies on choice trials. Eye movement data also suggested that young adults more successfully distinguished between strategies. Implications of these findings for understanding aging effects in complex arithmetic are discussed.     

Genetic architecture of context processing in late middle age: more than one underlying mechanism

Studies comparing young and older adults suggest a deficit in processing context information as a key mechanism underlying cognitive aging. However, the genetic architecture of context processing has not been examined. Consistent with previous results, we found evidence of functionally dissociable components of context processing accuracy in 1127 late middle-aged twins ages 51-60. One component emphasizes use of context cues to prepare responses (proactive cognitive control), and the other emphasizes adjustment of responses after probes are presented (reactive control). Approximately one-quarter of the variance in each component was accounted for by genes. Multivariate twin analysis indicated that genetic factors underlying two important components of context processing were independent of one another, thus implicating more than one underlying mechanism. Slower reaction time (RT) on noncontext processing trials was positively correlated with errors on the strongly proactive control component on which young adults outperform older adults, but RT was negatively correlated with errors on the strongly reactive control component on which older adults perform better. Although this RT measure was uncorrelated with chronological age in our age-homogeneous sample, slower RT was associated with performance patterns that were more like older adults. However, this did not generalize to other processing speed measures. Genetic correlations, which reflect shared genetic variance, paralleled the phenotypic correlations. There was also a positive genetic correlation between general cognitive ability and accuracy on the proactive control component, but there were still mostly distinct genetic influences underlying these measures. In contrast, the reactive control component was unrelated to general cognitive ability.     

Task coordination and aging: explorations of executive control processes in the task switching paradigm.

A number of models of cognitive aging suggest that older adults exhibit disproportionate performance decrements on tasks which require executive control processes. In a series of three studies we examined age-related differences in executive control processes and more specifically in the executive control processes which underlie performance in the task switching paradigm. Young and old adults were presented with rows of digits and were required to indicate whether the number of digits (element number task) or the value of the digits (digit value task) were greater than or less than five. Switch costs were assessed by subtracting the reaction times obtained on non-switch trials from trials following a task switch. Several theoretically interesting results were obtained. First, large age-related differences in switch costs were found early in practice. Second, and most surprising, after relatively modest amounts of practice old and young adults switch costs were equivalent. Older adults showed large practice effects on switch trials. Third, age-equivalent switch costs were maintained across a two month retention period. Finally, the main constraint on whether age equivalence was observed in task switching performance was memory load. Older adults were unable to capitalize on practice under high memory loads. These data are discussed in terms of their implications for both general and process specific cognitive aging models.     

A developmental study of practical problem solving in adults

Previous research indicates that young and middle-aged adults perform better than other age groups on problems similar to those they might encounter in their everyday lives. However, elderly adults have not performed better than other age groups on problems designed to give them the advantage. In order to ensure that the problems used in the present study were ones that elderly adults might encounter, elderly adults were recruited to help develop the problems. The resulting problems were administered to adults between the ages of 20 and 80. Performance was found to increase from the 20- to 40-year-old age group and decrease thereafter. Thus, when elderly adults devise practical problems that are intended to give elderly adults the advantage, the elderly adults still perform less well than do middle-aged adults.     

Age-Related Influences on Repetition Priming in the Verb Generation Task: Examining the Role of Response Competition

ABSTRACT

The identification-production framework suggests that aging is associated with a decline in production forms of repetition priming, particularly under test conditions that maximize response competition. The present study examined this prediction by testing young and healthy older adults in a single-encoding version of the verb generation task in which some items had one dominant verb response (low competition) or had no such dominant response (high competition). Further analyses examined whether priming and error rates were related to performance on neuropsychological tests purported to measure frontal lobe functioning. Priming was invariant across age groups and was not related to frontal lobe status in older adults, but frontal lobe status did predict task performance: low-frontal older adults made more errors than high-frontal older adults, particularly for high-competition items and items with high association strength. These results are not consistent with the identification-production framework, but are consistent with the conclusions that (a) aging is associated with invariance in the processes that support repetition priming in the verb generation task and (b) frontal lobe status in aging is related to verb generation performance.     

Young and old faces in young and old heads: the factor of age in face recognition.

Research on aging and face recognition has shown age-related differences that are reflected most clearly in false-alarm errors. Elderly subjects exceed young adults in false recognitions that new faces are "old." To determine if this difference between young and elderly subjects might differ for young versus elderly faces, an experiment was conducted in which half of the young and elderly subjects studied and recognized young and middle-aged faces, and the remainder studied and recognized middle-aged and elderly faces. Replicating prior research, age-related deficits in recognition accuracy (d') were reduced with older faces, and this effect generalized from measures of face recognition to measures of face-picture recognition. However, the age-related increase in false recognitions of faces was not affected by face age.     

Age differences in perceptions of memory strategy effectiveness for recent and remote memory

We examined whether young and older adults hold different beliefs about the effectiveness of memory strategies for specific types of memory tasks and whether memory strategies are perceived to be differentially effective for young, middle-aged, and older targets. Participants rated the effectiveness of five memory strategies for 10 memory tasks at three target ages (20, 50, and 80 years old). Older adults did not strongly differentiate strategy effectiveness, viewing most strategies as similarly effective across memory tasks. Young adults held strategy-specific beliefs, endorsing external aids and physical health as more effective than a positive attitude or internal strategies, without substantial differentiation based on task. We also found differences in anticipated strategy effectiveness for targets of different ages. Older adults described cognitive and physical health strategies as more effective for older than middle-aged targets, whereas young adults expected these strategies to be equally effective for middle-aged and older target adults.     

Age differences in feeling-of-knowing and confidence judgements as a function of knowledge domain

For two semantic knowledge domains, general and computer-related, feeling-of-knowing (FOK) and confidence level (CL) ratings and their relative accuracy were assessed in young, middle-aged, and older adults, after test difficulty was equated across age groups. Global memory self-efficacy beliefs were also assessed for each domain. As expected, greater age was associated with poorer memory self-efficacy beliefs only in the computer domain. The oldest two groups were found to be more underconfident than young adults when rating their FOK but not their CL, for computer items but not for general items. Statistical control of age differences in memory self-efficacy beliefs in the relevant domain greatly reduced this age effect on computer-related FOK ratings. This finding suggests that absolute FOK judgments are more closely related to memory self-efficacy beliefs than are CL judgments. Gamma correlations between judgments and recognition performance revealed that all age groups were equally accurate in FOK and in CL judgments, in both domains.     

Attempting to avoid false memories in the Deese/Roediger—McDermott paradigm: Assessing the combined influence of practice and warnings in young and old adults

On each of five study-test trials, young and old adults attempted to memorize the same list of 60 words (e.g., bed, rest, awake), which were blocked according to their convergence on four corresponding associates. Half of the participants in each age group were given an explicit warning about the DRM paradigm prior to encoding and were asked to attempt to avoid recalling any associated but nonpresented words (e.g., sleep). Lists were presented auditorily at either a fast (1,250 msec/word) or a slow (2,500 msec/word) rate. Without a warning, the probability of veridical recall across trials increased for both age groups; however, the probability of false recall across trials decreased only for young adults. When a warning about false recall was provided, young adults virtually eliminated false recall by the second trial. Even though old adults also used warnings to reduce false recall on Trial 1, they were still unable to decrease false memories across the remaining four study-test trials. Old adults also reduced false recall more with slow than with fast presentation rates. Taken together, these findings suggest that old adults have a breakdown in spontaneous, self-initiated source monitoring as reflected by little change in false recall across study-test trials but a preserved ability to use experimenter-provided warnings or slow presentation rates to reduce false memories.     

Error correction in discrimination training for children with autism

Three procedures for correcting errors made during discrimination training were examined: error statement (saying ‘no’), modeling the correct response, and No Feedback. Six children with autism (age 3–7 years) were taught to match words to pictures with each of the three procedures, and the number of trials to mastery was compared across conditions. Results varied across participants. Two participants performed as well with no feedback as they did with an error correction procedure; two acquired skills slightly more quickly with an error correction procedure than with no feedback, but showed no difference between error correction procedures; one did best with error statement; and one did best with modeling. Results indicate that the choice of error correction procedure can have a large effect on rate of skill acquisition but that the optimal procedure may vary across individuals. Copyright © 2006 John Wiley & Sons, Ltd.     

The relation of the conceptual self to recent and distant autobiographical memories

Based on the self-memory system model (SMS; Conway, Singer, & Tagini, 2004) of autobiographical memory, this study uses a large sample of young and middle-aged adults to investigate the relation between individuals’ current self-characteristics and the content of both their earliest childhood memory and a recent memory. In the first session, participants’ current self-characteristics were assessed. In the second session, individuals provided a written narrative of their earliest childhood memory and a more recent memory (within-participants design) and rated the self themes present in each memory. In keeping with the SMS model, findings show that current self-characteristics were reflected in individuals’ memories. As predicted, however, recent memories were more frequently linked to current self-characteristics than were earliest memories. All six current self-characteristics predicted the inclusion of these themes in recent memories, but only four self-characteristics were associated with memory themes in earliest memories. The relation between current self-characteristics and memory themes did not differ across young and middle-aged adults, suggesting developmental stability in these relations. Findings provide general support for the SMS model but also suggest possibilities for its extension and refinement.     

The relation of the conceptual self to recent and distant autobiographical memories

Based on the self-memory system model (SMS; Conway, Singer, & Tagini, 2004) of autobiographical memory, this study uses a large sample of young and middle-aged adults to investigate the relation between individuals' current self-characteristics and the content of both their earliest childhood memory and a recent memory. In the first session, participants' current self-characteristics were assessed. In the second session, individuals provided a written narrative of their earliest childhood memory and a more recent memory (within-participants design) and rated the self themes present in each memory. In keeping with the SMS model, findings show that current self-characteristics were reflected in individuals' memories. As predicted, however, recent memories were more frequently linked to current self-characteristics than were earliest memories. All six current self-characteristics predicted the inclusion of these themes in recent memories, but only four self-characteristics were associated with memory themes in earliest memories. The relation between current self-characteristics and memory themes did not differ across young and middle-aged adults, suggesting developmental stability in these relations. Findings provide general support for the SMS model but also suggest possibilities for its extension and refinement.     

Training effects on Raven's progressive matrices in young, middle-aged, and elderly adults

Previous training studies of fluid intellectual abilities have involved training on either figural relations or induction tasks. In the present study, young, middle-aged, and elderly adults were given training on another measure of fluid ability--Raven's Progressive Matrices. The training involved a strategy-modeling technique that lasted no more than a few minutes. The results indicated that (a) performance on the Raven decreased with increasing age, (b) training significantly improved performance, and (c) the effect of training did not differ as a function of the age or sex of the subjects. Thus, the results indicate that performance on the Raven can be significantly improved in a single, brief training session.     

Realism and illusion in Americans' temporal views of their life satisfaction: age differences in reconstructing the past and anticipating the future

We examined actual and perceived trajectories of change in life satisfaction in a national sample of 3,793 adults, ages 24 to 74 at baseline, who provided retrospective, present, and prospective ratings on two occasions 8 to 10 years apart. There was little actual change in satisfaction ratings, but there were age differences in anticipated change, with young adults expecting things to improve and older adults expecting decline. When we compared the actual (present) ratings with corresponding past or future ratings, older adults showed more temporal realism (retrospective and anticipatory ratings matched actual levels) than did young and middle-aged adults; in other words, young and middle-aged adults showed greater illusion (retrospective and prospective ratings overestimated or underestimated actual levels). At all ages, however, temporal realism was associated with more adaptive current functioning than was illusion. We discuss these findings from a life-span developmental perspective on motivational shifts from growth to maintenance and consider the implications of accuracy in evaluating the past and future.