Educational mobility and older adults' working memory updating ability: association and role of resilience.

OBJECTIVE: Previous research revealed that a low childhood socioeconomic status, including low parental education, correlates with impaired executive functioning. However, there is a lack of research on the association of working memory updating (WMU) ability, which is one of the major components of executive functioning, and of resilience with educational mobility. The purpose of the present two studies was to further examine these associations. METHOD: In Study 1, 180, 60-88-year old adults with different levels of educational mobility performed a WMU task. In Study 2, 130, 60-89-year old adults that had experienced different levels of upward educational mobility completed a WMU task and a resilience questionnaire. RESULTS: Study 1 revealed that extent of educational mobility was significantly positively associated with WMU ability. Study 2 revealed significant positive associations among extent of educational mobility, resilience, and WMU task performance. CONCLUSION: The results were discussed in terms of possible causal relations between the variables and implications for interventions that aim to enhance upward educational mobility and cognitive functioning in late adulthood.

Association between adolescents' socioeconomic status and working memory updating functioning: Role of parental educational involvement.

Family socioeconomic status (SES) is positively associated with executive functioning. This study tested whether parental educational involvement mediates this association. Two hundred and sixty, 12-15-year-old adolescents completed working memory updating (WMU) and general intelligence tasks, and questionnaires on SES and parental educational involvement. SES and WMU ability were positively associated; there was no difference between the fathers and mothers for three types of educational involvement. The mothers' behavioural involvement positively mediated the SES-WM updating association, whereas a negative mediation was observed for the mothers' intellectual involvement. The fathers' educational involvement did not play a significant mediating role. These results might inform interventions targeting educational involvement for enhancing the cognitive development of children from low SES families.

The effect of working memory capacity and training on intertemporal decision making in children from low-socioeconomic-status families.

Individuals differ in their tendency to discount delayed rewards. Low socioeconomic status (SES) has been found to be associated with strong delayed reward discounting (DRD), which in turn contributes to risky decision making and adverse behaviors. However, research on possible cognitive mediators of the negative association between SES and DRD, and on effects of cognitive training in low-SES adolescents, is largely lacking. In examining Chinese adolescents (aged 11-15 years; N = 207), Study 1 assessed which aspect of working memory (WM)-simple maintenance, simple manipulation, or updating-serves as mediator, which proved to be WM updating. Based on this outcome, in Study 2 Chinese adolescents (aged 12-14 years; N = 73) with low family SES were assigned to a WM updating training condition or a control condition. All participants performed DRD and WM tasks before and after treatment. The trained adolescents showed positive training effects on DRD, and this effect was specifically correlated with beneficial training effects on performance on a WM updating transfer task. These results support the role of WM updating in DRD and might inform training programs to promote more favorable decision making in low-SES adolescents.

The neural basis of individual differences in memory performance in young and older adults: Using the encoding/retrieval flip account as framework.

Aging is associated with cognitive decline, specifically in episodic memory. However, there are large individual differences in the extent of this decline and previous research suggests that these are associated with differences in executive functioning (EF). These EF differences, and associated differences in the encoding and retrieval of episodic information, have been linked to differences in the activation of particular brain regions. The "encoding/retrieval flip" (E/R flip) framework assumes deactivation and activation of specific brain regions during successful encoding and retrieval, respectively. The present study assessed whether this framework can be used to explain EF-based individual differences in memory performance of young and older participants. Young adults (N = 19) and older adults (N = 39) performed an incidental semantic encoding and memory recognition task in an fMRI setting, focusing on brain regions that show the E/R flip. The association between an index of EF and fMRI activity in brain regions showing the E/R flip was tested in each age group. EF predicted E/R flip activity in the older, but not young adults. These findings underscore the importance of individual differences in ageing research and provide empirical evidence for the association between EF and the E/R flip.

Training and transfer effects of extensive task-switching training in students.

The capacity to switch between tasks is a central component of executive functioning. Previous studies assessing effects of task-switch training have revealed mixed results, both in terms of processes that may be improved and the extent of beneficial effects on non-trained tasks. These studies primarily used few training sessions, which may have limited training and transfer effects. Here, 31 students were trained for 21 days on a cued switching task. Both the trained group and an active control group (n = 29) performed a number of cognitive tasks before and after training. Training reduced both switch and mixing costs, which mostly reached an asymptote after approximately four to six training sessions, although there were residual costs at the end of training. The switch cost reduction was restricted to trials with a short cue-stimulus onset interval (CSI). Training benefitted performance on another switching task, reflecting near transfer. However, this benefit was limited to the switch cost and to trials with a short CSI. There were no beneficial effects on far-transfer tasks measuring interference control, response inhibition, working memory, and general IQ. The results suggest that the present extensive training protocol, implicating overtraining, specifically enhanced the efficiency of processes involved in preparing for the relevant upcoming task set and/or inhibition of the previous task set. However, the lack of beneficial far-transfer effects is in line with previous cognitive training studies employing fewer training sessions, suggesting that the extent of training is not critical for (not) finding transfer effects.

Training and transfer effects of prospective memory training in 13- to 15-year-old children.

Prospective memory (PM) plays a crucial role in children's academic achievement and interpersonal relationships. However, there is a lack of studies exploring training and transfer effects of process-based PM training in healthy young adolescents. In the current study, 13- to 15-year-old children participated in an 8-day PM training program using the Virtual Week computer game. Transfer of training benefits was measured using other PM tasks (near transfer) and tasks measuring various aspects of executive function (EF) and general intelligence (far transfer). An active control group was used as comparison to assess transfer effects immediately after training and 3 and/or 6 months after training. After training, the trained children performed better on the trained PM task than the control children, and this benefit was still present after 6 months. Significant training-induced positive transfer was observed in tasks measuring time-based PM and working memory updating, although the benefits were rather short-lived. No differential, training-induced benefits were found for any of the other transfer tasks. These results suggest some limited potential of PM training to enhance some aspects of PM memory and EF in young adolescents.

Prospective memory training in young adults enhances trained-task but not transfer-task performance.

Training and transfer effects of prospective memory training have not been assessed in healthy young adults yet. The present study examined the effects of an 8-day prospective memory training programme using the Virtual Week computer game in 18-24-year-old students. Using the performance of an active control group as comparison, the study revealed a significant short-lived beneficial training-induced effect on a nearest-transfer task consisting of a different version of the trained task. No evidence was obtained for transfer effects to other tasks measuring prospective memory (near transfer), or to tasks measuring various executive functions or general intelligence (far transfer). These results were compared to those from a previous study in which an identical training and testing protocol was used in 13-15-year-old adolescents. This study did reveal some evidence of near and far transfer. The results of the two studies combined suggest a greater potential for prospective memory training to induce beneficial transfer effects in young adolescents than in young adults.

Training and transfer effects of response inhibition training in children and adults.

Response inhibition is crucial for mental and physical health but studies assessing the trainability of this type of inhibition are rare. Thirty-nine children aged 10-12 years and 46 adults aged 18-24 years were assigned to an adaptive go/no-go inhibition training condition or an active control condition. Transfer of training effects to performance on tasks assessing response inhibition, interference control, working memory updating, task-switching, and non-verbal fluid intelligence were assessed during 3- and 6-month follow-up sessions and/or an immediate post-training session. Significant training improvements and positive transfer effects to a similar response inhibition task with other stimuli were observed for both children and adults. Reliable albeit short-lived transfer effects were only found for the children, specifically to working memory updating and task switching. These results suggest some potential for response-inhibition training programs to enhance aspects of cognitive functioning in children but not adults.

Are training and transfer effects of working memory updating training modulated by achievement motivation?

Previous studies examining effects of working memory (WM) updating training revealed mixed results. One factor that might modulate training gains, and possibly also transfer of those gains to non-trained cognitive tasks, is achievement motivation. In the present Studies 1 and 2, students with either a high (HAM) or low (LAM) achievement motivation completed a 14-day visuospatial WM updating training program. In Study 2, the students also performed a set of tasks measuring other executive functions and fluid intelligence prior to and after training. In both studies, the HAM students displayed a larger training gain than the LAM students. Study 2 revealed that after training, both groups showed better performance on the near-transfer but not far-transfer tasks. Importantly, the differential training gain was not associated with better post-training performance for the HAM compared to the LAM students on any of the transfer tasks. These results are taken to support a modulatory role of achievement motivation on WM training benefits, but not on transfer of those benefits to other tasks. Possible reasons for the general improvement on the near-transfer tasks and the absence of a modulatory role of achievement motivation on transfer-task performance are discussed.

Effortful semantic decision-making boosts memory performance in older adults.

A major concern in age-related cognitive decline is episodic memory (EM). Previous studies indicate that both resource and binding deficits contribute to EM decline. Environmental support by task manipulations encouraging stronger cognitive effort and deeper levels of processing may facilitate compensation for these two deficits. To clarify factors that can counteract age-related EM decline, we assessed effects of cognitive effort (four levels) and level of processing (LoP, shallow/deep) during encoding on subsequent retrieval. Young (YAs, N = 23) and older (OAs, N = 23) adults performed two incidental encoding tasks, deep/semantic and shallow/perceptual. Cognitive effort was manipulated by varying decision-making demands. EM performance, indexed by d-prime, was later tested using a recognition task. Results showed that regardless of LoP, increased cognitive effort caused higher d-primes in both age groups. Compared to YAs, OAs showed a lower d-prime after shallow encoding across all cognitive effort levels, and after deep encoding with low cognitive effort. Deep encoding with higher levels of cognitive effort completely eliminated these age differences. Our findings support an environmental-compensatory account of cognitive ageing and can have important therapeutic implications.

Deficits in go/no-go task performance in male undergraduate high-risk alcohol users are driven by speeded responding to go stimuli.

BACKGROUND: Response disinhibition plays an important role in addictive behaviors. However, results of studies on the performance on response inhibition tasks of individuals evidencing potentially problematic levels of alcohol drinking are mixed. OBJECTIVES: We assessed conditions under which persons with a relatively high risk of alcohol dependence show inhibition deficits in such tasks and investigated the nature of those deficits. METHODS: Fifty-eight male undergraduate students, 27 of which were high-risk drinkers according to the Alcohol Use Disorders Identification Test, performed a go/no-go inhibition task with differing percentages of no-go trials (50% vs. 25%), stimulus presentation times (600 vs. 200 ms), and types of go and no-go stimuli (alcohol related vs. -unrelated). Response inhibition was indexed by response time (RT) to go trials and response accuracy on go and no-go trials. RESULTS: There were no differences between low- and high-risk drinkers on any of the three outcome measures under the 600-ms stimulus presentation condition. Under the 200-ms condition, the high-risk drinkers showed faster RTs to go stimuli, and more errors on both go- and no-go trials than the low-risk drinkers, irrespective of type and percentage of no-go stimuli. However, the accuracy differences between the two groups disappeared after controlling for the RT on go trials, suggesting a speed-accuracy trade-off. CONCLUSION: High-risk drinkers' response inhibition deficits are not restricted to alcohol-related cues and are especially likely to occur under conditions prompting fast responding. These findings could be used to inform treatment, suggesting the promotion of strategies aimed at preventing high-risk alcohol users from making quick decisions.

Cognitive performance in both clinical and non-clinical burnout.

Relatively little is known about cognitive performance in burnout. The aim of the present study was to further our knowledge on this topic by examining, in one study, cognitive performance in both clinical and non-clinical burnout while focusing on three interrelated aspects of cognitive performance, namely, self-reported cognitive problems, cognitive test performance, and subjective costs associated with cognitive test performance. To this aim, a clinical burnout patient group (n = 33), a non-clinical burnout group (n = 29), and a healthy control group (n = 30) were compared on self-reported cognitive problems, assessed by a questionnaire, as well as on cognitive test performance, assessed with a cognitive test battery measuring both executive functioning and more general cognitive processing. Self-reported fatigue, motivation, effort and demands were assessed to compare the different groups on subjective costs associated with cognitive test performance. The results indicated that the clinical burnout patients reported more cognitive problems than the individuals with non-clinical burnout, who in turn reported more cognitive problems relative to the healthy controls. Evidence for impaired cognitive test performance was only found in the clinical burnout patients. Relative to the healthy controls, these patients displayed some evidence of impaired general cognitive processing, reflected in slower reaction times, but no impaired executive functioning. However, cognitive test performance of the clinical burnout patients was related to larger reported subjective costs. In conclusion, although both the clinical and the non-clinical burnout group reported cognitive problems, evidence for a relatively mild impaired cognitive test performance and larger reported subjective cost associated with cognitive test performance was only found for the clinical burnout group.

Simple and complex rule induction performance in young and older adults: contribution of episodic memory and working memory.

This study tested the hypothesis that part of the age-related decline in performance on executive function tasks is due to a decline in episodic memory. For this, we developed a rule induction task in which we manipulated the involvement of episodic memory and executive control processes; age effects and neuropsychological predictors of task performance were investigated. Twenty-six younger (mean age, 24.0; range, 19-35 years) and 27 community-dwelling older adults (mean age, 67.5; range, 50-91 years) participated. The neuropsychological predictors consisted of the performance on tests of episodic memory, working memory, switching, inhibition and flexibility. Performance of the older adults was worse for the learning and memorization of simple rules, as well as for the more demanding executive control condition requiring the manipulation of informational content. Episodic memory was the only predictor of performance on the simple learning and memorization task condition whereas an increase in rule induction complexity additionally engaged working memory processes. Together, these findings indicate that part of the age-related decline on rule induction tests may be the result of a decline in episodic memory. Further studies are needed that examine the role of episodic memory in other executive function tasks in aging.

Reversal deficits in individuals with psychopathy in explicit but not implicit learning conditions.

BACKGROUND: Psychopathy is a severe personality disorder that has been linked to impaired behavioural adaptation during reinforcement learning. Recent electrophysiological studies have suggested that psychopathy is related to impairments in intentionally using information relevant for adapting behaviour, whereas these impairments remain absent for behaviour relying on automatic use of information. We sought to investigate whether previously found impairments in response reversal in individuals with psychopathy also follow this dichotomy. We expected response reversal to be intact when the automatic use of information was facilitated. In contrast, we expected impaired response reversal when intentional use of information was required. METHODS: We included offenders with psychopathy and matched healthy controls in 2 experiments with a probabilistic cued go/no-go reaction time task. The task implicated the learning and reversal of 2 predictive contingencies. In experiment 1, participants were not informed about the inclusion of a learning component, thus making cue-dependent learning automatic/incidental. In experiment 2, the instructions required participants to actively monitor and learn predictive relationships, giving learning a controlled/intentional nature. RESULTS: While there were no significant group differences in acquisition learning in either experiment, the results revealed impaired response reversal in offenders with psychopathy when controlled learning was facilitated. Interestingly, this impairment was absent when automatic learning was predominant. LIMITATIONS: Possible limitations are the use of a nonforensic control group and of self-report measures for drug use. CONCLUSION: Response reversal deficits in individuals with psychopathy are modulated by the context provided by the instructions, according to the distinction between automatic and controlled processing in these individuals.

Improved cognitive flexibility in serotonin transporter knockout rats is unchanged following chronic cocaine self-administration.

Cocaine dependence is associated with orbitofrontal cortex (OFC)-dependent cognitive inflexibility in both humans and laboratory animals. A critical question is whether cocaine self-administration affects pre-existing individual differences in cognitive flexibility. Serotonin transporter knockout (5-HTT(-/-) ) mice show improved cognitive flexibility in a visual reversal learning task, whereas 5-HTT(-/-) rats self-administer increased amounts of cocaine. Here we assessed: (1) whether 5-HTT(-/-) rats also show improved cognitive flexibility (next to mice); and (2) whether this is affected by cocaine self-administration, which is increased in these animals. Results confirmed that naïve 5-HTT(-/-) rats (n = 8) exhibit improved cognitive flexibility, as measured in a sucrose reinforced reversal learning task. A separate group of rats was subsequently trained to intravenously self-administer cocaine (0.5 mg/kg/infusion), and we observed that the 5-HTT(-/-) rats (n = 10) self-administered twice as much cocaine [632.7 mg/kg (±26.3)] compared with 5-HTT(+/+) rats (n = 6) [352.3 mg/kg (±62.0)] over 50 1-hour sessions. Five weeks into withdrawal the cocaine-exposed animals were tested in the sucrose-reinforced reversal learning paradigm. Interestingly, like the naïve 5-HTT(-/-) rats, the cocaine exposed 5-HTT(-/-) rats displayed improved cognitive flexibility. In conclusion, we show that improved reversal learning in 5-HTT(-/-) rats reflects a pre-existing trait that is preserved during cocaine-withdrawal. As 5-HTT(-/-) rodents model the low activity s-allele of the human serotonin transporter-linked polymorphic region, these findings may have heuristic value in the treatment of s-allele cocaine addicts.

Serotonin transporter knockout rats show improved strategy set-shifting and reduced latent inhibition.

Behavioral flexibility is a cognitive process depending on prefrontal areas allowing adaptive responses to environmental changes. Serotonin transporter knockout (5-HTT(-/-)) rodents show improved reversal learning in addition to orbitofrontal cortex changes. Another form of behavioral flexibility, extradimensional strategy set-shifting (EDSS), heavily depends on the medial prefrontal cortex. This region shows functional changes in 5-HTT(-/-) rodents as well. Here we subjected 5-HTT(-/-) rats and their wild-type counterparts to an EDSS paradigm and a supplementary latent inhibition task. Results indicate that 5-HTT(-/-) rats also show improved EDSS, and indicate that reduced latent inhibition may contribute as an underlying mechanism.

Association between working memory updating ability and cognitive reappraisal: An investigation into a modulatory role of the individual's sex.

Cognitive reappraisal has been shown to be an effective emotion regulation strategy that contributes to mental health. Previous studies focused on sex differences in the frequency of use and ability to use this strategy, and the association of fequency of use and ability with executive functioning. However, there is a lack of behavioral studies examining whether the involvement of executive functions in cognitive reappraisal use and ability differs for men and women. Such a sex difference may inform the design of cognitive interventions directed at enhancing cognitive reappraisal use and ability. The present study used a sample of 125 Chinese university students and focused on one key component of executive functioning: working memory updating. Frequency of cognitive reappraisal use was assessed by self-report. Ability to use cognitive reappraisal and working memory updating capacity were each assessed with a laboratory task. The results revealed no sex difference in cognitive reappraisal use or ability. However, of primary interest, the ability to apply cognitive reappraisal was associated with working memory updating performance, but only for women. If confirmed in further studies, these findings suggest that cognitive interventions in general, and working memory updating trainings more specifically, are more likely to enhance the ability to use cognitive reappraisal as a means to regulate emotions in women than in men.

A time-series perspective on executive functioning: The benefits of a dynamic approach to random number generation.

OBJECTIVES: Executive functioning (EF) is a key topic in neuropsychology. A multitude of underlying processes and constructs have been suggested to explain EF, which are measured by at least as many different neuropsychological tests. However, these tests often refer to summary statistics to quantify the construct under study, failing to capture the dynamic nature of EF. An alternative to these summary statistics is a time-series approach that quantifies all the available temporal information. METHODS: We used recurrence quantification analysis (RQA) to quantify the characteristics of any temporal pattern in random number generation data and we compared RQA to the traditional and static analysis of random number sequences. RESULTS: The traditional measures yield inconsistent results with increasing sequences length, both for computer-generated and human-generated sequences, whereas the RQA measures do not. CONCLUSION: The results suggest that a time-series approach does a better job at modelling what is happening on different time-scales, and, therefore, is better at explaining how EF is changing in the course of the random number generation task. We argue that it is likely that these findings also apply to other neuropsychological EF tests, and that a time-series approach is an important addition to the study of EF.

So what'cha want? The impact of individualised rewards on associative learning in psychopathic offenders.

Psychopathic individuals typically present with associative learning impairments under explicit learning conditions. The present study aimed to investigate whether the formation of stimulus-outcome associations, as well as updating of these associations after changed contingencies, could be improved by using rewards with sufficiently high subjective values. To this end, 20 psychopathic offenders, 17 non-psychopathic offenders and 18 healthy controls performed a passive avoidance task with a reversal phase under three motivational conditions, using naturalistic rewards. The subjective values of the rewards were assessed a priori for each individual participant using a visual analogue scale. The correspondence of these values to their internal representation was confirmed by analyses of brain potentials. Analyses using both signal detection theory and classical approaches indicated that psychopathic offenders performed worse compared to the other groups during passive avoidance learning. However, using the signal detection approach, we found this deficiency to be present only when a hypothetical reward was used ('neutral reward' condition), whereas psychopathic offenders performed similar to the other groups when naturalistic rewards could be obtained ('low reward' and 'high reward' conditions). Furthermore, traditional analyses suggested that psychopathic offenders had more hits than the other groups during reversal learning, but the signal detection approach indicated that no effects of group or condition were present. Analysis of win-stay and lose-shift behaviour showed that psychopathic offenders were less likely to stay with a rewarded response during passive avoidance learning in the neutral reward condition. In addition, regardless of experimental phase or condition, psychopathic offenders were less likely to stop responding to a particular stimulus after receiving negative feedback. Although the approaches employed did not lead to unequivocal results, our findings suggest that psychopathic offenders do have the ability to adapt their behaviour to environmental contingencies when positive reinforcers with sufficiently high subjective values are used.

Training and transfer effects of working memory updating training in male abstinent long-term methamphetamine users.

Methamphetamine use is associated with cognitive impairments, including executive functioning. These impairments might be cause and/or effect of the drug (re-)use and have, therefore, motivated interventions to improve cognitive functioning. Until now, only very few studies have examined the effect of training working memory updating (WMU), one of the core executive functions, in this population. In the present study, 32 long-term male abstinent methamphetamine inpatients received either a multiple-session WMU training or an active control treatment. All participants performed a number of tasks assessing WMU, inhibition, and task-switching ability- before and after treatment. The WMU-trained patients improved their performance on the trained task and on a non-trained WMU task, reflecting near transfer. However, there was no beneficial training-induced effect for the other tasks, indicating the absence of far transfer. Possible treatment implications of these findings were discussed.