Working Memory Capacity Depends on Attention Control, but Not Selective Attention

Predicting the effectiveness of binaural beats on working memory

Working memory is vital for short-term information processing. Binaural beats can enhance working memory by improving attention and memory consolidation through neural synchronization. However, individual differences in cognitive and neuronal functioning affect effectiveness of binaural beats, necessitating personalized approaches. This study aimed to develop a machine learning model to predict binaural beats's effectiveness on working memory using electroencephalography. Sixty healthy participants underwent a 5-min electroencephalography recording, an initial working memory evaluation, 15 min of binaural beats stimulation, and a subsequent working memory evaluation using digit span tests of increasing difficulty. Recall accuracy and response times were measured. Differential scores from pre-evaluation and post-evaluation labeled participants as active or inactive to binaural beats stimulation. electroencephalography data, recorded using 14 electrodes, provided brain activity estimates across theta, alpha, beta, and gamma frequency bands, resulting in 56 features (14 channels × 4 bands) for the machine learning model. Several classifiers were tested to identify the most effective model. The weighted K-nearest neighbors model achieved the highest accuracy (90.0%) and area under the receiver operating characteristic curve (92.24%). Frontal and parietal electroencephalography channels in theta and alpha bands were crucial for classification. This study's findings offer significant clinical insights, enabling informed interventions and preventing resource inefficiency.

Attentional load leads to distinct changes in early and late cortical processing of target visibility under visual masking

Visual masking and attentional selection play important roles in controlling information processing for perception. Using an experimental design combining metacontrast with attentional load, we investigated the time course of changes in event-related potentials under different attentional load and masking conditions. The behavioral results indicated significant effects of attentional load on masking functions (i.e., masking strength as a function of stimulus onset asynchrony between target and mask). The analyses of neural activities revealed significant effects of masking and attentional load on early components located over occipital and parieto-occipital scalp sites. There were also significant modulations in the late positivity range centered over centro-parietal electrodes. However, the nature of modulations in early and late components was different. These findings overall highlight the diverse nature of masking and attentional influences on visual processing, particularly suggesting that attentional load in the visual field may have distinct effects at different stages of perceptual processing.

Evidence for the Beneficial Effect of Reward on Working Memory: A Meta-Analytic Study

Rewards act as external motivators and can improve performance in various cognitive tasks. However, previous research demonstrated mixed findings regarding the effect of reward on working memory (WM) performance, and the question of whether reward enhances WM performance is arguable. It remains unclear how the effect of reward on WM can be influenced by various factors, such as types of reward and experimental paradigms. In this meta-analytic study, we systematically investigated the effect of reward on WM by analyzing data from 51 eligible studies involving a total of 1767 participants. Our results showed that reward robustly enhanced WM performance, with non-monetary rewards inducing more benefits than monetary rewards. This may be because, while both types of reward could induce extrinsic motivation, non-monetary rewards enhanced intrinsic motivation while monetary rewards reduced it. Notably, all three reward methods-reward binding, reward expectation, and subliminal reward-effectively improved WM performance, with the reward binding paradigm exhibiting the greatest effects. This finding suggests that the reward effect can be attributed to both increasing the total amount of WM resources and improving the flexibility of resource reallocation. Moreover, the type of WM, the experimental paradigms, and the outcome measures are three moderators that should be jointly considered when assessing the reward effects on WM. Overall, this meta-analytic study provides solid evidence that reward improves WM performance and reveals possible mechanisms underlying these improvements.

The relation between cognitive functioning and activities of daily living in normal aging, mild cognitive impairment, and dementia: a meta-analysis

Literature suggests that dementia and, more generally, cognitive impairment affect the capacity to carry out activities of daily living (ADL) in aging. However, it is important to decipher the weight of specific cognitive domains and neurodegenerative profiles mainly related to ADL difficulties. A meta-analysis was conducted to investigate the nature and strength of the association between cognitive functioning and ADL in healthy older adults, mild cognitive impairment (MCI), and dementia. A comprehensive search of the PubMed, PsycINFO (PROQUEST), and Scopus databases for cross-sectional or longitudinal studies up until December 2022. Our meta-analytic results revealed that: overall, instrumental ADL (IADL) showed a significant association with executive functioning, in particular, abstraction ability/concept formation, set-shifting, and processing speed/complex attention/working memory, regardless of type of participants (i.e., healthy older adults, MCI, and dementia); whereas ADL (both basic ADL, BADL, and IADL) significantly correlated with global cognitive functioning and long-term verbal memory, with a moderator effect of clinical condition (e.g., increasing ES based on the level of cognitive impairment). Moreover, visuospatial and language abilities significantly correlated with ADL, mainly when performance-based tasks were used for ADL assessment. These findings emphasize the importance of neuropsychological assessment in aging to early identify people most at risk of functional decline and shed light on the need to consider specific cognitive abilities in rehabilitation programs.

Individual differences in attention control: A meta-analysis and re-analysis of latent variable studies

A meta-analysis and re-analysis of prior latent variable studies was conducted in order to assess whether there is evidence for individual differences in broad attention control abilities. Data from 90 independent samples and over 23,000 participants suggested that most (84.4%) prior studies find evidence for a coherent attention control factor with average factor loadings of .51. This latent attention control factor was related to other cognitive ability factors including working memory, shifting, fluid intelligence, long-term memory, reading comprehension, and processing speed, as well as to self-reports of task-unrelated thoughts and task specific motivation. Further re-analyses and meta-analyses suggest that the results remained largely unchanged when considering various possible measurement issues. Examining the factor structure of attention control suggested evidence for sub-components of attention control (restraining, constraining and sustaining attention) which could be accounted for a by a higher-order factor. Additional re-analyses suggested that attention control represents a broad ability within models of cognitive abilities. Overall, these results provide evidence for attention control abilities as an important individual differences construct.

Unpacking the overlap between Autism and ADHD in adults: A multi-method approach

The overlap between Autism and Attention-Deficit Hyperactivity Disorder (ADHD) is widely observed in clinical settings, with growing interest in their co-occurrence in neurodiversity research. Until relatively recently, however, concurrent diagnoses of Autism and ADHD were not possible. This has limited the scope for large-scale research on their cross-condition associations, further stymied by a dearth of open science practices in the neurodiversity field. Additionally, almost all previous research linking Autism and ADHD has focused on children and adolescents, despite them being lifelong conditions. Tackling these limitations in previous research, 5504 adults - including a nationally representative sample of the UK (Study 1; n = 504) and a large pre-registered study (Study 2; n = 5000) - completed well-established self-report measures of Autism and ADHD traits. A series of network analyses unpacked the associations between Autism and ADHD at the individual trait level. Low inter-item connectivity was consistently found between conditions, supporting the distinction between Autism and ADHD as separable constructs. Subjective social enjoyment and hyperactivity-impulsivity traits were most condition-specific to Autism and ADHD, respectively. Traits related to attention control showed the greatest Bridge Expected Influence across conditions, revealing a potential transdiagnostic process underlying the overlap between Autism and ADHD. To investigate this further at the cognitive level, participants completed a large, well-powered, and pre-registered study measuring the relative contributions of Autism and ADHD traits to attention control (Study 3; n = 500). We detected age- and sex-related effects, however, attention control did not account for the covariance between Autism and ADHD traits. We situate our findings and discuss future directions in the cognitive science of Autism, ADHD, and neurodiversity, noting how our open datasets may be used in future research.

Post-encoding task engagement not attentional load is detrimental to awake consolidation

The fate of new memories depends partly on the cognitive state experienced immediately following encoding. Wakeful rest, relative to task engagement, benefits retention and this effect is typically explained through a consolidation account: rest is theorised to provide a state of minimal interference, which would otherwise disrupt consolidation. Yet, the determinants of consolidation interference, notably the contribution of attention, remain poorly characterised. Through a repeated measures design, we investigated attention load's impact on consolidation. In three phases, participants encountered a set of nonwords and underwent immediate recognition testing, experienced a 5-min delay condition, and completed a delayed recognition test for the nonwords. This cycle repeated for each phase before proceeding to the next. Delay conditions comprised of wakeful rest and two sustained attention to response tasks (SART) that were of low (SART-fixed) and high (SART-random) attention load. Immediate memory was matched across conditions, but delayed recognition was poorer after completing the SART-fixed and SART-random conditions, relative to rest. There was no difference between the two SART conditions. These data provide insights into the factors that contribute to the success of consolidation and indicate that the attention load of a task does not determine the magnitude of consolidation interference and associated forgetting.