Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

Contextual interference effects in sequence learning for young and older adults

Practice of different tasks in a random order induces better retention than practicing them in a blocked order, a phenomenon known as the contextual interference (CI) effect. Our purpose was to investigate whether the CI effect exists in sequence learning, such that practicing different sequences in a random order will result in better learning of sequences than practicing them in blocks, and whether this effect is affected by aging. Subjects practiced a serial reaction time task where a set of three 4-element sequences were arranged in blocks or in a random order on 2 successive days. Subjects were divided into 4 groups based on a 2-GROUP (young or old) by 2-ORDER (random or blocked practice) between-subject design. Three days after practice (Day 5), subjects were tested with practiced and novel sequences to evaluate sequence-specific learning. The results replicate the CI effect in sequence learning in both young and older adults. Older adults retained sequences better when trained in a random condition than in a blocked condition, although the random condition incurs greater task switching costs in older adults during practice. Our study underscores the distinction between age-related effects on learning vs. performance, and offers practical implications for enhancing skill learning in older adults.     

Trial-and-error learning improves source memory among young and older adults

Trial-and-error learning, relative to errorless learning, has been shown to impair memory among older adults, despite evidence from young adults that errors may afford memorial benefits through richer encoding. However, previous studies on the effects of errorless versus trial-and-error learning in older adults has required production of errors based on perceptual cues. We hypothesized that producing errors conceptually associated with targets would boost memory for the encoding context in which information was studied, especially for older adults who do not spontaneously elaborate on targets at encoding. We report two studies examining the impact of generating errors during learning on source memory among young and older adults, with a process dissociation procedure employed in Study 1, and source memory assessed directly in Study 2. In both studies, participants were shown semantic category cues and generated an exemplar either with or without errors. In Study 1, for both age groups trial-and-error learning was associated with lower familiarity-based memory and higher recollection-based memory relative to errorless learning, and the latter effect was more marked for older than younger adults. Similarly, in Study 2, trial-and-error learning was associated with better source memory relative to errorless learning, particularly for the older adults. We argue that trial-and-error learning can enhance source memory and confer memorial benefits when making such errors facilitates semantic elaboration, especially for older adults who do not spontaneously engage in strategic encoding.     

Functional learning among children, adolescents, and young adults

This study examined age-related differences in functional learning performance manifested among children, adolescents, and young adults placed in a two-cue ecology involving cues with direct relation and inverse relations with the criterion. On each trial, participants were instructed to consider the values taken by two cues, predict from these two values the value of a criterion, and finally examine the corresponding feedback value (i.e., the correct value of the criterion for this situation). The authors' hypotheses were that: (a) very few children under 11 years of age would be able to learn how to use the inverse relation cue for predicting the criterion, although they would be able to correctly use the direct relation cue; (b) most adolescents and young adults over 17 years of age would be able to learn how to use the inverse relation cue and combine it with the direct relation cue; and (c) adolescents between 11 and 17 years of age would show various levels of achievement. In general, these predictions were confirmed. Not until 11 years was a substantial proportion of participants (23%) able to reject the direct relation hypothesis and select the inverse relation hypothesis during learning.     

Gradually learning to increase gait propulsion in young unimpaired adults

Distorted visual feedback (DVF) may employ both implicit and explicit approaches to enhance motor learning. Our purpose was to test the effect of DVF of gait propulsion on the capacity to alter propulsive forces, and to determine the biomechanical determinants of propulsion. Seventeen young unimpaired individuals walked for three minutes of baseline (no feedback), then completed three randomly ordered, 10-minute Learning conditions: Real, 10DVF, and 20DVF. During the DVF conditions, we gradually decreased the feedback value without the participants' knowledge. For all Learning conditions, participants were instructed to maintain the propulsive force between two targets representing ±1 standard deviation as obtained from baseline. A one-minute retention trial without any feedback was performed immediately after Learning. Participants increased propulsive forces and trailing limb angle in both DVF conditions that persisted through retention; however, no change in ankle plantarflexion moment was noted. These findings offer promise of translation to clinical populations with propulsion deficits and require combined implicit and explicit learning components.     

Pragmatics aid referent disambiguation and word learning in young children and adults

How do children succeed in learning a word? Research has shown robustly that, in ambiguous labeling situations, young children assume novel labels to refer to unfamiliar rather than familiar objects. However, ongoing debates center on the underlying mechanism: Is this behavior based on lexical constraints, guided by pragmatic reasoning, or simply driven by children's attraction to novelty? Additionally, recent research has questioned whether children's disambiguation leads to long-term learning or rather indicates an attentional shift in the moment of the conversation. Thus, we conducted a pre-registered online study with 2- and 3-year-olds and adults. Participants were presented with unknown objects as potential referents for a novel word. Across conditions, we manipulated whether the only difference between both objects was their relative novelty to the participant or whether, in addition, participants were provided with pragmatic information that indicated which object the speaker referred to. We tested participants’ immediate referent selection and their retention after 5 min. Results revealed that when given common ground information both age groups inferred the correct referent with high success and enhanced behavioral certainty. Without this information, object novelty alone did not guide their selection. After 5 min, adults remembered their previous selections above chance in both conditions, while children only showed reliable learning in the pragmatic condition. The pattern of results indicates how pragmatics may aid referent disambiguation and learning in both adults and young children. From early ontogeny on, children's social-cognitive understanding may guide their communicative interactions and support their language acquisition.

Research Highlights

• We tested how 2-3-year-olds and adults resolve referential ambiguity without any lexical cues.
• In the pragmatic context both age groups disambiguated novel word-object-mappings, while object novelty alone did not guide their referent selection.
• In the pragmatic context, children also showed increased certainty in disambiguation and retained new word-object-mappings over time.
• These findings contribute to the ongoing debate on whether children learn words on the basis of domain-specific constraints, lower-level associative mechanisms, or pragmatic inferences.

     

Susceptibility to walking balance perturbations in young adults is largely unaffected by anticipation

Despite progress in understanding the mechanisms governing walking balance control, the number of falls in our older adult population is projected to increase. Falls prevention systems and strategies may benefit from understanding how anticipation of a balance perturbation affects the planning and execution of biomechanical responses to mitigate instability. However, the extent to which anticipation affects the proactive and reactive adjustments to perturbations has yet to be fully investigated, even in young adults. Our purpose was to investigate the effects of anticipation on susceptibility to two different mechanical balance perturbations – namely, treadmill-induced perturbations and impulsive waist-pull perturbations. Twenty young adults (mean ± standard deviation age: 22.8 ± 3.3 years) walked on a treadmill without perturbations and while responding to treadmill belt (200 ms, 6 m/s²) and waist-pull (100 ms, 6% body weight) perturbations delivered in the anterior and posterior directions. We used 3D motion capture to calculate susceptibility to perturbations during the perturbed and preceding strides via whole-body angular momentum (WBAM) and anterior-posterior margin of stability (MoS_AP). Contrary to our hypotheses, anticipation did not affect young adults' susceptibility to walking balance challenges. Conversely, perturbation direction significantly affected walking instability. We also found that susceptibility to different perturbation contexts is dependent on the outcome measure chosen. We suggest that the absence of an effect of anticipation on susceptibility to walking balance perturbations in healthy young adults is a consequence of their having high confidence in their reactive balance integrity. These data provide a pivotal benchmark for the future identification of how anticipation of a balance challenge affects proactive and reactive balance control in populations at risk of falls.     

The role of conscious processing of movements during balance by young and older adults

We examined the effect of verbalization of a phylogenetic motor skill, balance, in older and young adults with a low or a high propensity for conscious verbal engagement in their movements (reinvestment). Seventy-seven older adults and 53 young adults were categorized as high or low reinvestors, using the Movement Specific Reinvestment Scale, which assesses propensity for conscious processing of movements. Participants performed a pre- and post-test balance task that required quiet standing on a force-measuring plate. Prior to the post-test, participants described their pre-test balancing performance (verbalization) or listed animals (non-verbalization). Only young adults were affected by verbalization, with participants with a high propensity for reinvestment displaying increased medial-lateral entropy and participants with a low propensity for reinvestment displaying increased area of sway and medial-lateral sway variability following the intervention. The possible explanations for these results are discussed.     

Implicit learning of predictive relationships in three-element visual sequences by young and old adults

Knowledge of sequential relationships enables future events to be anticipated and processed efficiently. Research with the serial reaction time task (SRTT) has shown that sequence learning often occurs implicitly without effort or awareness. Here, the authors report 4 experiments that use a triplet-learning task (TLT) to investigate sequence learning in young and older adults. In the TLT, people respond only to the last target event in a series of discrete, 3-event sequences or triplets. Target predictability is manipulated by varying the triplet frequency (joint probability) and/or the statistical relationships (conditional probabilities) among events within the triplets. Results reveal that both groups learned, though older adults showed less learning of both joint and conditional probabilities. Young people used the statistical information in both cues, but older adults relied primarily on information in the 2nd cue alone. The authors conclude that the TLT complements and extends the SRTT and other tasks by offering flexibility in the kinds of sequential statistical regularities that may be studied as well as by controlling event timing and eliminating motor response sequencing.     

Different neuromuscular control mechanisms regulate static and dynamic balance: A center-of-pressure analysis in young adults

The analysis of the center of pressure (CoP) trajectory, derived from force platforms, is a widely accepted measure to investigate postural balance control. The CoP trajectory could be analyzed as a physiological time-series through a general stochastic modeling framework (i.e., Stabilogram Diffusion Analysis (SDA)). Critical point divides short-term from long-term regions and diffusion coefficients reflect the level of stochastic activity of the CoP. Sample Entropy (SampEn) allows quantifying the CoP complexity in terms of regularity. Thus, this study aimed to understand whether SDA and SampEn could discriminate the neuromuscular control mechanisms underpinning static and dynamic postural tasks. Static balance control and its relationship with dynamic balance control were investigated through the CoP velocity (Mean Velocity) and the area of the 95th percentile ellipse (Area95). Balance was assessed in 15 subjects (age: 23.13 ± 0.99 years; M = 9) over a force platform under two conditions: static (ST) and dynamic, both in anterior-posterior (DAP) and medio-lateral (DML) directions. During the DAP and DML, subjects stood on an unstable board positioned over a force platform. Short-term SDA diffusion coefficients and critical points were lower in ST than in DAP and DML (p < 0.05). SampEn values resulted greater in ST than in DAP and DML (p < 0.001). As expected, lower values of Area95 (p < 0.001) and Mean Velocity (p < 0.001) were detected in the easiest condition, the ST, compared to DAP and DML. No significant correlations between static and dynamic balance performances were detected. Moreover, differences in the diffusion coefficients were detected comparing DAP and DML (p < 0.05). In the anterior-posterior direction, the critical point occurred at relatively small intervals in DML compared to DAP (p < 0.001) and ST (p < 0.001). In the medio-lateral direction, the critical point differed only between DAP and DML (p < 0.05). Overall, SDA analysis pointed out a less tightly regulated neuromuscular control system in the dynamic tasks, with closed-loop corrective feedback mechanisms called into play at different time intervals in the three conditions. SampEn results reflected more attention and, thus, less automatic control mechanisms in the dynamic conditions, particularly in the medio-lateral task. The different neuromuscular control mechanisms that emerged in the static and dynamic balance tasks encourage using both static and dynamic tests for a more comprehensive balance performance assessment.     

Spatial cognition and behavior in young and elderly adults: implications for learning new environments

Young and elderly women's performances on scene-recognition, distance-ranking, route-execution, and map-placement tasks were compared in familiar and novel supermarkets to seek evidence of an age-related deficit in spatial cognitive performance, a benefit of environmental familiarity, and an age-related decrement in the efficiency of spatial learning. Results suggested that younger adults acquired spatial information in a novel environment more quickly than did elderly adults, but findings indicated neither an age-related deficit in spatial cognitive performance nor a benefit of environmental familiarity. Scores from psychometric tests produced low correlations with cognitive task performance. Of the behaviors observed during exploration and route execution, only 1 was significantly correlated with cognitive task performance. Standing without scanning was negatively correlated with performance on 3 tasks for elderly adults only.     

Stimulus specificity in avoidance learning

The present experiments address the issue of stimulus specificity in fear and avoidance learning. First, it was established that light stimuli are effective warning signals (WS) in shuttle avoidance. Then light stimuli were shown to produce conditioned suppression in the conditioned emotional response situation comparable to that produced by noise conditioned stimuli. Finally, the effectiveness of noise onset and noise offset as feedback signals was tested. This was assessed under conditions of immediate and delayed termination of a light WS. Delayed termination of a light WS interfered with avoidance learning and the introduction of noise offset as a feedback signal enhanced it. The only demonstration of stimulus specificity was the failure of noise onset to function as a feedback signal.     

Feedback specificity, learning opportunities, and learning

Although increasing feedback specificity is generally beneficial for immediate performance, it can undermine certain aspects of the learning needed for later, more independent performance. The results of the present transfer experiment demonstrate that the effects of increasing feedback specificity on learning depended on what was to be learned, and these effects were partially mediated through the opportunities to learn how to respond to different task conditions during practice. More specific feedback was beneficial for learning how to respond to good performance and detrimental for learning how to respond to poor performance. The former relationship was partially mediated by feedback specificity's effect on learning opportunities during practice. The results have implications for designing feedback interventions and training to maximize the learning of various aspects of a task.     

Postural muscle responses following changing balance threats in young, stable older, and unstable older adults

The authors determined the postural muscle response to support surface perturbations, in relation to aging and level of stability of 16 young adults and 32 older adults who were classified into stable (SOA) and unstable (UOA) groups on the basis of their functional balance abilities. Forward and backward support surface translations of various amplitudes and velocities were used so that postural responses of the standing adults could be elicited. The thigh and leg postural muscle responses were recorded with surface electromyography (EMG). The older groups had significantly longer onset latency in the anterior postural muscles, smaller integrated EMG in the posterior muscles, and greater extent of integrated EMG attenuation over time. The UOA showed longer onset latency in the gastrocnemius following slow backward perturbation and used a greater percentage of the functional capacity of the gastrocnemius muscle than the SOA did. Those findings indicate that the SOA and UOA had limited ability to adapt to changing balance threats; the UOA were more limited than the SOA. When designing balance training programs, therefore, therapists should consider the adult's level of functional stability.     

Measuring reversal learning: Introducing the Variable Iowa Gambling Task in a study of young and old normals

We developed a modification of the Iowa Gambling Task (IGT) to test whether it is primarily a measure of reversal learning. Named the Variable IGT (VIGT), the design involves a contingency reversal midway through the task. Two versions of the task enabled us to study the effect of a stronger prepotent response on the ability to identify and adapt to contingency reversal. A significant reversal delay was observed among normal young players with a more dominating reward response. Although transitory, this delay is comparable to the characteristic behavioural impairment observed in patients with damage to the ventromedial prefrontal cortex (VM), addicts, psychopaths and individuals with other self-destructive disorders: They persist in a previously rewarding behaviour despite long-term heavy costs. We also conducted the VIGT in a sample of healthy elderly adults. Results from this sample do not support VM-like or risk-aversive theories of ageing but are inconclusive regarding the frontal ageing hypothesis. Overall, our findings indicate that the VIGT is a sensitive and versatile measure of reversal learning and will serve as a useful instrument in future studies of affective decision making, addiction, and other self-destructive behaviour.     

Autobiographical memory specificity after manipulating retrieval cues in adults reporting childhood sexual abuse

Traumatized samples have relative difficulty in generating specific autobiographical memories on a cue word task, compared to nonexposed controls. Simultaneously, trauma is associated with highly specific intrusive trauma memories in day-to-day life. Possibly, day-to-day intrusions and memories generated to cue words rely on different retrieval processes, with the former dependent on close associations between retrieval cues and specific memory representations (direct retrieval), and the latter on iterative retrieval cycles through a hierarchical memory system (generative retrieval). This study investigated this distinction using two versions of the cue word task, designed to promote generative and direct retrieval, respectively, in participants with or without a history of child sexual abuse (CSA). The data demonstrated that CSA participants were less specific than nonabused controls to generative retrieval cues, but this difference disappeared with direct retrieval cues. This interaction was stronger in CSA participants with relatively greater posttraumatic stress and remained significant when participants with past or current major depressive disorder were excluded and also when only those participants with corroborated CSA were included.