Individual differences in memory and attention processes in prospective remembering.

Successful prospective memory (PM) involves not only detecting that an environmental cue requires action (i.e., prospective component), but also retrieval of what is supposed to be done at the appropriate moment (i.e., retrospective component). The current study examined the role of attention and memory during PM tasks that placed distinct demands on detection and retrieval processes. Using a large-scale individual differences design, participants completed three PM tasks that placed high demands on detection (but low demands on retrieval) and three tasks that placed high demands on retrieval (but low demands on detection). Additionally, participants completed three attention control, retrospective memory, and working memory tasks. Latent variable structural equation modeling showed that the prospective and retrospective components of PM were jointly influenced by multiple cognitive abilities. Critically, attention and retrospective memory fully mediated the relation between working memory and prospective memory. Furthermore, only attention uniquely predicted PM detection, whereas only retrospective memory uniquely predicted PM retrieval. These findings highlight the value of independently assessing different PM components and suggest that both attention and memory abilities must be considered to fully understand the dynamic processes underlying prospective remembering.

The Effects of Working Memory versus Adaptive Visual Search Control Training on Executive Cognitive Function.

There is considerable debate about whether Working Memory (WM) training specifically results in far-transfer improvements in executive cognitive function (ECF) rather than improvements on tasks similar to the training tasks. There has also been recent interest in whether WM training can improve ECF in clinical populations with clear deficits in ECFs. The current study examined the effects of WM training compared with non-WM adaptive Visual Search (VS) control training (15 sessions over 4 weeks) on various measures of ECF, including delay discounting (DD) rate, inhibition on flanker, color and spatial Stroop tasks, and drinking in a community-recruited sample with Alcohol Use Disorder (AUD, 41 men, 41 women, mean age = 21.7 years), who were not in treatment or seeking treatment, and non-AUD healthy controls (37 men, 52 women, mean age = 22.3 years). Both WM and VS training were associated with improvements on all ECF measures at 4 weeks and 1-month follow-up. WM and VS training were associated with reductions in both DD rates and interference on Stroop and Flanker tasks in all participants, as well as reductions in drinking in AUD participants that remained apparent one month post training. The results suggest that nonspecific effects of demanding cognitive training, as opposed to specific WM training effects, could enhance ECF, and that such enhancements are retained at least one-month post-training.

The role of proactive interference in working memory training and transfer.

Recent work on working memory training has produced conflicting results regarding the degree and generality of transfer to other cognitive processes. However, few studies have investigated possible mechanisms underlying transfer. The current study was designed to test the role of proactive interference in working memory training and transfer. Eighty-six young adults participated in a pretest-posttest design, with ten training sessions in between. In the two working memory training conditions, subjects performed an operation span task, with one condition requiring recall of letters on every trial (operation-letters), whereas the other condition alternated between letters, digits, and words as the to-be-remembered items across trials (operation-mix). These groups were compared to an active-control group (visual-search). Working memory, verbal fluency, and reading comprehension measures were administered in pretest and posttest sessions. All groups significantly increased their performance over the ten training sessions. There was evidence of strategy-specific benefits on transfer, such that transfer to working memory measures was higher for the operation-letters group on tasks specifically involving letters, and no differential transfer to working memory tests without letters, to verbal fluency, or to reading comprehension. The results indicate that proactive interference does not appear to play a causal role in determining transfer from working memory training, and instead a strategy account based on stimulus content provides a more parsimonious explanation for the pattern of training and transfer.

The Influence of Individual Differences in Cognitive Ability on Working Memory Training Gains.

Working memory training research has produced mixed results in terms of finding benefits beyond the trained tasks (i.e., transfer). One potential limitation is that the research thus far has failed to isolate the specific combination of factors that makes working memory training work best. Individual differences in cognitive ability at pretest may be an important factor, suggesting possible aptitude-by-treatment interactions. Baseline cognitive ability could be (a) positively related, (b) negatively related, or (c) unrelated to training task improvements. The relationship between ability and training gains is important given the idea that larger training improvements should lead to greater transfer. However, the majority of training studies tend to be under-powered to examine individual differences. We pooled studies conducted in related labs to increase power while minimizing differences between studies. In the studies that were identified for this project, young adults completed complex span training and working memory and/or fluid intelligence as pretest measures. The combined samples from seven studies resulted in a sample of 192 participants. Analyses focused on the relationship between pretest cognitive ability and training performance across training days. There was no evidence that individuals lower in cognitive ability improved more than high-ability subjects on the training tasks. Instead, we found a positive relationship for both working memory and fluid intelligence measured at pretest with the amount of training improvement. In addition, the association between pretest working memory and working memory training performance appears to be domain-general - verbal and visuospatial content do not produce differential relationships.

Task manipulation effects on the relationship between working memory and go/no-go task performance.

Go/no-go tasks are widely used in psychology as measures of inhibition, mind-wandering, and impulsivity, but relatively little research has explored the impact that task manipulations have on task performance and measurement of the intended psychological constructs. Experiment 1 investigated the differences between perceptual and semantic versions of go/no-go tasks and how task performance relates to individual differences in working memory capacity (WMC), a widely-studied cognitive construct. The type of decision performed on the go/no-go stimuli influenced performance, but not the relationship with WMC. Experiment 2 examined the potential of inter-stimulus interval (ISI), which influenced go/no-go performance, along with the relationships with WMC. However, the type of decision had effects on performance above and beyond that of the ISI. The results are discussed in relation to the psychological literature using go/no-go tasks as behavioral indices of inhibition and mind-wandering, and in the context of previous investigations of individual differences in WMC.

The influence of thought probes on performance: Does the mind wander more if you ask it?

Mind-wandering has emerged in the past decade as a popular topic in many areas of psychological research. Numerous studies have demonstrated the potential costs and benefits of mind-wandering in relation to ongoing task performance, along with more recent work examining the nature of different types of mind-wandering. A common method of measuring mind-wandering in laboratory research is to embed self-report thought probes at random intervals within an ongoing task. However, a critical issue to determine is whether or not the presence of the thought probes fundamentally alters how an individual typically performs on the task. In the current study, N = 149 participants completed a sustained attention to response task (SART) with and without the presence of mind-wandering thought probes. In addition, participants completed operation and symmetry span measures of working memory capacity, as several studies have examined the relationship between individual differences in working memory capacity and mind-wandering using thought probes on the SART. The results indicate that SART performance does not differ whether thought probes are included or not. Individuals higher in working memory capacity produced better SART performance in the conditions with and without thought probes. In addition, individuals in working memory capacity were negatively correlated with mind-wandering frequency. The results indicate that thought probe measurement is a non-reactive method to measure mind-wandering in attention and inhibition tasks.

Using Rapid Serial Visual Presentation to Measure Set-Specific Capture, a Consequence of Distraction While Multitasking.

This method uses a rapid serial visual presentation (RSVP) paradigm to measure the cost of distraction when participants maintain multiple search goals. The protocol identifies two types of distraction within a single task - contingent attentional capture and set-specific capture - that represent different types of limitations of cognitive processing. Participants search for letters in two or more "target" ink colors (e.g., green and orange) within a continuous RSVP stream of heterogeneously colored letters, while ignoring two peripheral RSVPs of letters. Upon detecting a target, participants are to identify the letter. On some trials, target-colored distractors appear in the periphery just prior to the presentation of a target, causing a drop in target identification performance. Contingent attentional capture is observed by examining performance on trials in which the peripheral distractor is the same color as the target on that trial (e.g., both orange). Set-specific capture is represented by performance on trials in which the peripheral distractor is target-colored (e.g., orange), but not the same color as the target on that trial (e.g., green.) By varying the amount of time (i.e., the number of stimuli appearing) between the presentation of the distractor and the target, researchers can observe how participants recover from these distraction costs over time. As compared to static displays that are often used to measure contingent attentional capture, the dynamic display produces much larger effects, allowing the researcher to identify subtle effects of smaller manipulations. An unusual aspect of our design is that it employs a continuous display; "filler" stimuli connect one trial to the next seamlessly, and participants respond during this interval whenever they detect a target. The continuous display reduces chance performance to near-zero levels (rather than 50%) and provides researchers with a more sensitive measure of performance differences across trial types.

Predictors of Effective Working Memory Training in Individuals with Alcohol Use Disorders.

BACKGROUND: Low working memory (WM) capacity is associated with alcohol use disorders (AUDs). The importance of WM to adaptive functioning has led to a recent influx of studies attempting to improve individual WM capacity using various cognitive training methods. The present study aimed to examine the efficacy of complex WM training for improving WM capacity among individuals with AUD. METHODS: Individuals were randomized to complete either adaptive WM training or active control training. We applied a methodologically rigorous and structured approach, including a battery of near and moderate transfer measures in those with AUDs and a control group. Additionally, we examined cognitive factors (at baseline) and other predictors of adherence, training task improvement, and transfer. RESULTS: Results suggest improved WM in individuals with AUDs and controls, as evidenced by improved scores on several transfer measures, after adaptive WM training. However, individuals with AUDs showed poorer adherence and less improvement on the training tasks themselves. Neither IQ, WM, sex, nor condition predicted adherence. Level of training task performance, baseline WM, and IQ predicted transfer task improvement. CONCLUSIONS: This is the first study to rigorously examine both the efficacy of WM training in those with AUDs, and predictors of successful training program adherence and transfer in a large sample. Among study completers, results suggest that AUD status does not predict training improvement and transfer. However, AUD status did predict lower program adherence. WM training was more effective in those with higher cognitive ability at baseline. This study provides direct translation to the development of cognitive interventions for treating AUD.

Practice reduces set-specific capture costs only superficially.

Contingent attentional capture costs are doubled or tripled under certain conditions when multiple attentional sets guide visual search (e.g., "search for green letters" and "search for orange letters"). Such "set-specific" capture occurs when a potential target that matches one attentional set (e.g., a green stimulus) impairs the ability to identify a temporally proximal target that matches another attentional set (e.g., an orange stimulus). In the present study, we examined whether these severe set-specific capture effects could be attenuated through training. In Experiment 1, half of participants experienced training consisting of mostly trials involving a set switch from distractor to target, while the other half experienced training consisting of mostly trials in which a set switch was not required. Upon test, participants trained on set switches produced greatly reduced set-specific capture effects compared to their own pretraining levels and compared to participants trained on trials without a set switch. However, in Experiments 2 and 3, we found that these training effects did not transfer to a new color context or even a single new target color, indicating that they were specific and involved low-level associative learning. We concluded that set-specific capture is pervasive and largely immutable, even with practice.

Working memory capacity and intra-individual variability of proactive control.

Two datasets of 110 young adults were examined to investigate the relationship between individual differences in working memory capacity (WMC) and dynamic cognitive control. The results delve into the specific differences between high- and low-WMC individuals' ability to enact and maintain cognitive control using the AX version of the continuous performance test (AX-CPT). Compared to high-WMC individuals, low-WMC individuals: (a) made more errors, specifically to AX targets; (b) exhibited a partial shift to proactive control with more time-on-task; (c) had more exaggerated slower AX target responses in the tail of the response time distribution; and (d) were equally likely to adjust control after conflict. These results fit with the dual mechanisms of cognitive control theory and goal-maintenance account, and further clarify how individual differences in WMC manifests as intra-individual variability in cognitive control.

What's working in working memory training? An educational perspective.

Working memory training programs have generated great interest, with claims that the training interventions can have profound beneficial effects on children's academic and intellectual attainment. We describe the criteria by which to evaluate evidence for or against the benefit of working memory training. Despite the promising results of initial research studies, the current review of all of the available evidence of working memory training efficacy is less optimistic. Our conclusion is that working memory training produces limited benefits in terms of specific gains on short-term and working memory tasks that are very similar to the training programs, but no advantage for academic and achievement-based reading and arithmetic outcomes.