Evaluating the relationship between change in performance on training tasks and on untrained outcomes

The State of Cognitive Control in Language Processing

Understanding language requires readers and listeners to cull meaning from fast-unfolding messages that often contain conflicting cues pointing to incompatible ways of interpreting the input (e.g., "The cat was chased by the mouse"). This article reviews mounting evidence from multiple methods demonstrating that cognitive control plays an essential role in resolving conflict during language comprehension. How does cognitive control accomplish this task? Psycholinguistic proposals have conspicuously failed to address this question. We introduce an account in which cognitive control aids language processing when cues conflict by sending top-down biasing signals that strengthen the interpretation supported by the most reliable evidence available. We also provide a computationally plausible model that solves the critical problem of how cognitive control "knows" which way to direct its biasing signal by allowing linguistic knowledge itself to issue crucial guidance. Such a mental architecture can explain a range of experimental findings, including how moment-to-moment shifts in cognitive-control state-its level of activity within a person-directly impact how quickly and successfully language comprehension is achieved.

Exploring the Specificity, Synergy, and Durability of Auditory and Visual Computer Gameplay Transfer Effects in Healthy Older Adults

OBJECTIVES

To determine whether auditory and visual computer games yield transfer effects that (a) are modality-specific to verbal memory (auditory stimulus presentation) and visual-processing tests, (b) affect working memory and processing speed, (c) are synergistic for combined game-type play, and (d) are durable.

METHOD

A Pilot Study (N = 44) assessed visual transfer effects in a two-group pre-post design. The Main Study (N = 151) employed a 2 (visual games: yes, no) × 2 (auditory games: yes, no) × 3 (test session: pretest, post-test, follow-up) design, allowing different training groups to act as active controls for each other. Neuropsychological test scores were aggregated into verbal-memory (auditory presentation), visual-processing, working-memory, and processing-speed indexes.

RESULTS

Visual-processing and working-memory pre-post-training change scores were differentially modulated across the four gameplay groups in the main sample, demonstrating transfer effects differing across both active- and passive-control groups. Visual training yielded modality-specific transfer effects in both samples, transfer to working memory in the main sample, and transfer to processing speed in the pilot sample. There were no comparable transfer effects for auditory training. Combined-visual-and-auditory training failed to yield synergistic effects or any significant transfer effects. Visual-processing transfer effects remained significant at follow-up.

DISCUSSION

Visual and auditory games differentially modulated transfer effects. Domain-specific visual transfer effects were found at post-test and were durable at follow-up. Visual gameplay holds potential to ameliorate age-related cognitive decline in visual cognition.

Feasibility of Intensive Ecological Sampling of Tinnitus in Intervention Research

OBJECTIVE

To assess whether adults with bothersome tinnitus will complete multiple ecological momentary assessments (EMAs) per day, including those during a therapeutic intervention trial. EMA is defined as repeated sampling of subjects' current behaviors and experiences in real time.

STUDY DESIGN

Twelve-week longitudinal cohort study conducted from August 28, 2017, to December 14, 2017.

SETTING

Online only.

SUBJECTS

Thirty adults with self-reported bothersome nonpulsatile tinnitus of >6 months' duration.

METHODS

Participants completed 2 weeks of EMA text surveys 7 times per day (preintervention), followed by 8 weeks of EMA questions 4 times per day (during intervention), concluding with 2 weeks of EMA questions 7 times per day (postintervention) for a total of 420 surveys over 12 weeks. During the 8-week intervention period, participants used a commercially available auditory-intensive online cognitive brain training program for 20 minutes per day, 5 times per week (total, 800 minutes). The primary outcome measures were compliance with EMA surveys, as measured by survey response rates, and participant-reported effects of EMA on their tinnitus bother.

RESULTS

Of the 30 participants in this study (20 women and 10 men; median age, 54 years [range, 47-64 years]), 25 participants completed the study protocol (83%). Participants completed a median 87% of EMA surveys (range, 67%-99%). Qualitative analysis of free-text responses found that participants did not report negative side effects of the EMA.

CONCLUSION

Excellent participant compliance can be achieved with multiweek temporally rigorous EMA sampling. EMA sampling can successfully be conducted during an intervention. EMA is a promising sampling methodology in tinnitus research.

Do "Brain-Training" Programs Work?

In 2014, two groups of scientists published open letters on the efficacy of brain-training interventions, or "brain games," for improving cognition. The first letter, a consensus statement from an international group of more than 70 scientists, claimed that brain games do not provide a scientifically grounded way to improve cognitive functioning or to stave off cognitive decline. Several months later, an international group of 133 scientists and practitioners countered that the literature is replete with demonstrations of the benefits of brain training for a wide variety of cognitive and everyday activities. How could two teams of scientists examine the same literature and come to conflicting "consensus" views about the effectiveness of brain training?In part, the disagreement might result from different standards used when evaluating the evidence. To date, the field has lacked a comprehensive review of the brain-training literature, one that examines both the quantity and the quality of the evidence according to a well-defined set of best practices. This article provides such a review, focusing exclusively on the use of cognitive tasks or games as a means to enhance performance on other tasks. We specify and justify a set of best practices for such brain-training interventions and then use those standards to evaluate all of the published peer-reviewed intervention studies cited on the websites of leading brain-training companies listed on Cognitive Training Data (www.cognitivetrainingdata.org), the site hosting the open letter from brain-training proponents. These citations presumably represent the evidence that best supports the claims of effectiveness.Based on this examination, we find extensive evidence that brain-training interventions improve performance on the trained tasks, less evidence that such interventions improve performance on closely related tasks, and little evidence that training enhances performance on distantly related tasks or that training improves everyday cognitive performance. We also find that many of the published intervention studies had major shortcomings in design or analysis that preclude definitive conclusions about the efficacy of training, and that none of the cited studies conformed to all of the best practices we identify as essential to drawing clear conclusions about the benefits of brain training for everyday activities. We conclude with detailed recommendations for scientists, funding agencies, and policymakers that, if adopted, would lead to better evidence regarding the efficacy of brain-training interventions.

No Evidence That Short-Term Cognitive or Physical Training Programs or Lifestyles Are Related to Changes in White Matter Integrity in Older Adults at Risk of Dementia

Cognitive and physical activities can benefit cognition. However, knowledge about the neurobiological mechanisms underlying these activity-induced cognitive benefits is still limited, especially with regard to the role of white matter integrity (WMI), which is affected in cognitive aging and Alzheimer’s disease. To address this knowledge gap, we investigated the immediate and long-term effects of cognitive or physical training on WMI, as well as the association between cognitive and physical lifestyles and changes in WMI over a 6-month period. Additionally, we explored whether changes in WMI underlie activity-related cognitive changes, and estimated the potential of both trainings to improve WMI by correlating training outcomes with WMI. In an observational and interventional pretest, posttest, 3-month follow-up design, we assigned 47 community-dwelling older adults at risk of dementia to 50 sessions of auditory processing and working memory training (n = 13), 50 sessions of cardiovascular, strength, coordination, balance and flexibility exercises (n = 14), or a control group (n = 20). We measured lifestyles trough self-reports, cognitive training skills through training performance, functional physical fitness through the Senior Fitness Test, and global cognition through a cognitive test battery. WMI was assessed via a composite score of diffusion tensor imaging-based fractional anisotropy (FA) of three regions of interest shown to be affected in aging and Alzheimer’s disease: the genu of corpus callosum, the fornix, and the hippocampal cingulum. Effects for training interventions on FA outcomes, as well as associations between lifestyles and changes in FA outcomes were not significant. Additional analyses did show associations between cognitive lifestyle and global cognitive changes at the posttest and the 3-month follow-up (β ≥ 0.40, p ≤ 0.02) and accounting for changes in WMI did not affect these relationships. The targeted training outcomes were related to FA scores at baseline (cognitive training skills and FA composite score, r_s = 0.68, p = 0.05; functional physical fitness and fornix FA, r = 0.35, p = 0.03). Overall, we found no evidence of a link between short-term physical or cognitive activities and WMI changes, despite activity-related cognitive changes in older adults at risk of dementia. However, we found positive associations between the two targeted training outcomes and WMI, hinting at a potential of long-term activities to affect WMI.

Cognitive change is more positively associated with an active lifestyle than with training interventions in older adults at risk of dementia: a controlled interventional clinical trial

BACKGROUND

While observational studies show that an active lifestyle including cognitive, physical, and social activities is associated with a reduced risk of cognitive decline and dementia, experimental evidence from corresponding training interventions is more inconsistent with less pronounced effects. The aim of this study was to evaluate and compare training- and lifestyle-related changes in cognition. This is the first study investigating these associations within the same time period and sample.

METHODS

Fifty-four older adults at risk of dementia were assigned to 10 weeks of physical training, cognitive training, or a matched wait-list control condition. Lifestyle was operationalized as the variety of self-reported cognitive, physical, and social activities before study participation. Cognitive performance was assessed with an extensive test battery prior to and after the intervention period as well as at a 3-month follow-up. Composite cognition measures were obtained by means of a principal component analysis. Training- and lifestyle-related changes in cognition were analyzed using linear mixed effects models. The strength of their association was compared with paired t-tests.

RESULTS

Neither training intervention improved global cognition in comparison to the control group (p = .08). In contrast, self-reported lifestyle was positively associated with benefits in global cognition (p < .001) and specifically in memory (p < .001). Moreover, the association of an active lifestyle with cognitive change was significantly stronger than the benefits of the training interventions with respect to global cognition (ps < .001) and memory (ps < .001).

CONCLUSIONS

The associations of an active lifestyle with cognitive change over time in a dementia risk group were stronger than the effects of short-term, specific training interventions. An active lifestyle may differ from training interventions in dosage and variety of activities as well as intrinsic motivation and enjoyment. These factors might be crucial for designing novel interventions, which are more efficient than currently available training interventions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01061489 . Registered February 2, 2010.

Seven Pervasive Statistical Flaws in Cognitive Training Interventions

The prospect of enhancing cognition is undoubtedly among the most exciting research questions currently bridging psychology, neuroscience, and evidence-based medicine. Yet, convincing claims in this line of work stem from designs that are prone to several shortcomings, thus threatening the credibility of training-induced cognitive enhancement. Here, we present seven pervasive statistical flaws in intervention designs: (i) lack of power; (ii) sampling error; (iii) continuous variable splits; (iv) erroneous interpretations of correlated gain scores; (v) single transfer assessments; (vi) multiple comparisons; and (vii) publication bias. Each flaw is illustrated with a Monte Carlo simulation to present its underlying mechanisms, gauge its magnitude, and discuss potential remedies. Although not restricted to training studies, these flaws are typically exacerbated in such designs, due to ubiquitous practices in data collection or data analysis. The article reviews these practices, so as to avoid common pitfalls when designing or analyzing an intervention. More generally, it is also intended as a reference for anyone interested in evaluating claims of cognitive enhancement.

Closed-loop rehabilitation of age-related cognitive disorders

Cognitive deficits are common in older adults, as a result of both the natural aging process and neurodegenerative disease. Although medical advancements have successfully prolonged the human lifespan, the challenge of remediating cognitive aging remains. The authors discuss the current state of cognitive therapeutic interventions and then present the need for development and validation of more powerful neurocognitive therapeutics. They propose that the next generation of interventions be implemented as closed-loop systems that target specific neural processing deficits, incorporate quantitative feedback to the individual and clinician, and are personalized to the individual's neurocognitive capacities using real-time performance-adaptive algorithms. This approach should be multimodal and seamlessly integrate other treatment approaches, including neurofeedback and transcranial electrical stimulation. This novel approach will involve the generation of software that engages the individual in an immersive and enjoyable game-based interface, integrated with advanced biosensing hardware, to maximally harness plasticity and assure adherence. Introducing such next-generation closed-loop neurocognitive therapeutics into the mainstream of our mental health care system will require the combined efforts of clinicians, neuroscientists, bioengineers, software game developers, and industry and policy makers working together to meet the challenges and opportunities of translational neuroscience in the 21st century.

Online Attention Training for Older Adults

Evidence suggests that cognitive training interventions can improve older adults' cognitive performance. Successful training programs are adaptable and train multiple cognitive domains to target individual strengths and weaknesses. Computerized training programs are useful because they allow older adults to easily access training. This pilot study used an online attention training program, ATTENTION WORKOUT™, to enhance three aspects of attention- coordination, allocation, and selective focus -in community-dwelling older adults randomized to either an abbreviated (n=13) or an extended (n=17) practice training program over a 6-week period. Participants in the extended practice group significantly improved on selective focus reading distraction tasks with unrelated words (U=39.5; Z=-2.34; p=.02) and blanks (U=26.5; Z=-3.05; p=.002) as well as a matching attributes task (U=49.5; Z=-2.33; p=.02). The extended practice group significantly improved on three tasks of coordinating attention - radio-tuning (U=30; Z=-2.73; p=.01), circuit-breaker resetting (U=46; Z=-2.24; p=.03), and the combination of the two tasks (U=15; Z=-3.51; p<.0001) - as well as a memory generalization task (U=20; Z=-3.27; p=.001). A post-test satisfaction survey found both groups enjoyed the program, but the abbreviated practice group felt the tasks were more difficult. These findings suggest online attention training programs, like ATTENTION WORKOUT, can improve attention-related skills in community-dwelling older adults.