Contralateral delay activity as a marker of visual working memory capacity: a multi-site registered replication

Visual working memory (VWM) is a temporary storage system capable of retaining information that can be accessed and manipulated by higher cognitive processes, thereby facilitating a wide range of cognitive functions. Electroencephalography (EEG) is used to understand the neural correlates of VWM with high temporal precision, and one commonly used EEG measure is an event-related potential called the contralateral delay activity (CDA). In a landmark study by Vogel and Machizawa (2004), the authors found that the CDA amplitude increases with the number of items stored in VWM and plateaus around three to four items, which is thought to represent the typical adult working memory capacity. Critically, this study also showed that the increase in CDA amplitude between two-item and four-item arrays correlated with individual subjects’ VWM performance. Although these results have been supported by subsequent studies, a recent study suggested that the number of subjects used in experiments investigating the CDA may not be sufficient to detect differences in set size and to provide a reliable account of the relationship between behaviorally measured VWM capacity and the CDA amplitude. To address this, the current study, as part of the #EEGManyLabs project, aims to conduct a multi-site replication of Vogel and Machizawa's (2004) seminal study on a large sample of participants, with a pre-registered analysis plan. Through this, our goal is to contribute to deepening our understanding of the neural correlates of visual working memory

Disruption of working memory and contralateral delay activity by nociceptive stimuli is modulated by task demands

Top–down processes allow the selection and prioritization of information by limiting attentional capture by distractors, and these mechanisms depend on task demands such as working memory (WM) load. However, bottom–up processes give salient stimuli a stronger neuronal representation and provoke attentional capture. The aim of this study was to examine the effect of salient nociceptive stimuli on WM while manipulating task demands. Twenty-one healthy participants performed a change detection task during which they had to determine whether 2 successive visual arrays were different or the same. Task demands were modulated by manipulating the WM load (set size included 2 or 4 objects to recall) and by the correspondence between the 2 successive visual arrays (change vs no change). Innocuous stimuli (control) or nociceptive stimuli (distractors) were delivered during the delay period between the 2 visual arrays. Contralateral delay activity and laser-evoked potentials were recorded to examine neural markers of visual WM and nociceptive processes. Nociceptive stimuli decreased WM performance depending on task demands (all P < 0.05). Moreover, compared with control stimuli, nociceptive stimuli abolished the increase in contralateral delay activity amplitude for set size 4 vs set size 2 (P = 0.04). Consistent with these results, laser-evoked potential amplitude was not decreased when task demands were high (P = 0.5). These findings indicate that WM may shield cognition from nociceptive stimuli, but nociceptive stimuli disrupt WM and alter task performance when cognitive resources become insufficient to process all task-relevant information. Corresponding author. Address: Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Blvd des Forges, C.P. 500, Trois-Rivières, QC, Canada G9A 5H7. Tel.: 819-376-5011, Ext.: 3998; fax: 819-376-5204. E-mail address: [email protected] (M. Piché). Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article. Received July 06, 2021 Received in revised form September 22, 2021 Accepted October 08, 2021 © 2022 International Association for the Study of Pai

Visual Working Memory Encoding and Action: An Investigation using fNIRS and Mouse-tracking

Visual working memory (VWM) guides the motor system by temporarily keeping relevant information in mind. As an interface between perception and action, VWM plays a critical role in supporting goal-directed behavior. Research on the relationship between VWM and action has primarily focused on the effect of VWM on motor output. Traditional approaches index outcome responses, such as accuracy, but this practice provides limited information on underlying VWM processes. Conversely, the influence of action on VWM processes has received less attention and its neural correlates are not well understood. In this thesis, I examined VWM-action links using functional near-infrared spectroscopy (fNIRS) and mouse-tracking to record real-time trajectories of participants\u27 motor responses. Experiment 1 aimed to understand the relationship between movement dynamics, VWM performance, and their associated neural activity in a standard change detection task. Experiments 2 and 3 focused on the effect of action on VWM encoding using change detection tasks that manipulated task-relevance of the action (Experiment 2) and action-relevance of the items held in VWM (Experiments 2 & 3). The results showed that action enhanced VWM encoding for action-relevant features but impaired memory for action-irrelevant features. Moreover, the frontoparietal VWM network was differentially associated with action-relevant and action-irrelevant memory performance. Together, these findings suggest a trade-off between action and VWM encoding, where the representations of action-relevant features are prioritized but action-irrelevant features are suppressed. These results support and expand on the motor-induced encoding effect, demonstrating how action enhances VWM encoding for features that are action-relevant

Contributions of Familiarity and Chunking to Visual Working Memory Capacity

Visual working memory (VWM) is responsible for the temporary storage of visual information required for perception and cognition. The capacity of VWM is surprisingly limited to three or four items. Despite decades of research, the nature of the capacity limit is still unclear, in part due to uncertainty about the main factors contributing to this limit. We approached this issue by exploring two instances in which memory performance is enhanced. Firstly, while controlling stimulus complexity and similarity, familiarity produced significant increases in both encoding rate and capacity. However, familiarity gained from training observers to simply recognise the stimuli did not produce any benefits for change detection. Secondly, the inclusion of statistical regularities in the displays produced significantly improved recall. However, only subjects with explicit awareness of the statistical regularities showed improvement, whereas unaware subjects showed no change in their recall performance. We extended this result by observing whether contralateral delay activity (CDA), a neural marker of the number of item-based representations held in VWM, reduces with explicit chunking. Although recall performance was significantly better, the CDA did not appear to index equivalent number of chunks, suggesting that online representations do not change with the use of explicit chunking. Instead, the behavioural benefit appears to rely on retrieval of a long-term memory representation (LTM) when recall is tested. These results indicate a major influence of LTM in guiding VWM performance. Behavioural data collected at the end of the trial, such as change detection or probed recall, appear inadequate for fully examining the nature of VWM. An embedded-process framework, in which activated LTM representations can fluidly shift into the focus of attention, is useful in interpreting these results and understanding the cognitive processes involved in memory

ELECTROPHYSIOLOGICAL MECHANISMS FOR PREPARING CONTROL IN TIME

Cognitive control is critical in guiding goal-directed behavior, preparing neural resources and adapting processing to promote optimal action in a given environment. According to the Dual Mechanisms of Control theory (Braver, 2012), control can be dichotomized into proactive and reactive modes of control, utilized reciprocally in ahead-of-time preparation versus last-minute, stimulus-evoked reaction. Although a substantial body of work has tested differences between proactive control and reactive control, the underlying assumption of proactive control as a unitary process has not been systematically investigated. Very little is known as to how or when proactive control is initiated, sustained, or implemented. As time is an integral building block of perception, cognition, and action (Buhusi & Meck, 2005), one should expect temporal information to be integrated into proactive control. Cognitive control is costly (Shenhav, Botvinick, & Cohen, 2013), and a temporally-guided modulation of control may offer substantial cost savings. By measuring proactive control on a sub-second time-scale, we can begin to gauge whether dissociable sub-types of proactive control are utilized demanding on temporal demands. Moreover, by comparing proactive control processes across different temporal demands, we can parse out when different aspects of control are computed and implemented. Through a meta-analytic review and three empirical experiments, this dissertation provides insight into how timing dynamics may influence the computation, maintenance, and instantiation of proactive cognitive control. First, a meta-analysis on the cued control literature reveals that seemingly trivial experimental parameters shape the use of proactive versus reactive control. Two EEG studies then demonstrate how modulating timing dynamics influences prefrontal mechanisms for preparatory cognitive control. In a final EEG study, we compare the mechanisms utilized to retain control goals versus visuo-spatial working memory items. Overall, this dissertation elucidates several novel electrophysiological mechanisms by which timing information is implemented in the computation and retention of cognitive control rules. Further, we provide evidence that individual differences in impulsivity and working memory shape distinct aspects of preparation. The findings reported here make clear that timing information is critical in guiding proactive control processes, and support a fundamental reconsideration of proactive control based on temporal dynamics

Training of visual selective attention in older adults

Úvod: Vliv kognitivního tréninku na kognitivní výkon je v zájmu výzkumníků již dlouhá léta. Tréninky jsou nejčastěji zaměřeny na pozornost, pracovní paměť či exekutivní funkce, které jsou ovlivněné věkem. Cílem bývá nejenom ověřit, zda je možné zlepšit výkon v trénované úloze, ale i v jiných netrénovaných úlohách, u kterých se předpokládá propojení s trénovanou úlohou. S ohledem na stárnutí populace jsou tyto intervence čím dál častěji zaměřeny na starší populaci. Cíl: Studie popisovaná v disertační práci se zaměřuje na zjištění efektů tréninku vizuální selektivní pozornosti a pracovní paměti prostřednictvím aplikace Filter It - naše verze kanonické verze Change Detection Task (CDT) pro mobilní zařízení - tablet. Metoda: Zkoumaný soubor zahrnoval 62 starších osob ve věku 60-75 let, které byly dle blokové randomizace rozděleny do experimentální a aktivní kontrolní skupiny. Experimentální skupina trénovala prostřednictvím aplikace Filter It, aktivní kontrolní skupina absolvovala trénink pomocí aplikace Clouds. Cílem bylo změřit efektivitu 6týdenního vizuálního adaptivního tréninku CDT administrovaného na tabletu, a to ve smyslu specifického tréninkového efektu (Filter It - paradigma Barvy a Tvary) a efektu transferu na měřítka pracovní paměti (Řazení písmen a čísel, Visual Patterns Test) a exekutivní...Introduction: The effect of cognitive training on cognitive performance has been of interest to researchers for many years. Training is most often targeted at attention, working memory, or executive functions that are affected by age. The goal is usually not only to test whether it is possible to improve performance on the trained task, but also on other untrained tasks that are assumed to be related to the trained task. Given the aging of the population, these interventions are increasingly targeting the older adults. Aim: The study aims to examine the effects of training visual selective attention and working memory using Filter It - our version of the canonical Change Detection Task (CDT) for a mobile device, the tablet. Method: The sample consisted of 62 older adults aged 60-75 years, who were divided into experimental and active control group through the block randomization. The experimental group trained using the Filter It application, and the active control group trained using the Clouds application. The aim was to examine the effectiveness of a 6-week individual visual adaptive CDT training administered on a tablet, in terms of specific training improvements (Filter It - Colors and Shapes paradigms) and transfer effect on measures of working memory (Letter Number Sequencing, Visual...Department of PsychologyKatedra psychologieFaculty of ArtsFilozofická fakult

On the functional relationship between visual working memory and numerical acuity

openÈ presente nella letteratura scientifica una lunga serie di elementi coerenti con l'ipotesi di una dissociazione tra la memoria di lavoro visuo-spaziale e il sistema deputato all'elaborazione delle informazioni relative alla numerosità degli stimoli. Ciononostante, negli ultimi anni è emerso un numero crescente di evidenze a sostegno dell’ipotesi che un sistema che elabora la numerosità pura dalla nascita esista ma non sia di per sé sufficiente a generare le rappresentazioni utilizzate per guidare le risposte. Si osserva invece una sovrapposizione con la memoria di lavoro visiva in termini funzionali e di risorse legata all'integrazione di informazioni spaziali e all'interferenza delle informazioni relative alle altre caratteristiche fisiche degli stimoli. In questo studio, abbiamo replicato lo studio di Piazza et al. (2011) che costituisce il riferimento empirico a sostegno dell’ipotesi di una dissociazione tra approssimazione numerica e memoria di lavoro visuo-spaziale. La capacità di memoria di lavoro visiva è stata misurata utilizzando un recente paradigma di change-detection e sono state corrette alcune imperfezioni metodologiche dello studio di Piazza e colleghi, arrivando comunque a replicare la mancanza di correlazione originariamente osservata. La presenza di evidenze contraddittorie ha costituito quindi la base per una riflessione teorica e metodologica finalizzata a spiegare i nostri risultati allo stato dell’arte attuale e ad orientare la ricerca futura sul ruolo della memoria di lavoro nella stima numerica

Perceptual and Cognitive Load in Autism – An Electrophysiological and Behavioural Approach

Attention is a fundamentally important cognitive process and is required to efficiently navigate the world. Whilst altered attentional processes have been frequently observed in autistic people the differences seen suggest that attentional processes are different, however not necessarily deficient. In fact, aspects of superior visual perceptual ability and enhanced perceptual capacity have frequently been reported. The goal of the present thesis was to extend our knowledge of enhanced perceptual capacity under the framework of the Load Theory and to extend the findings to more active components of attention. To address this aim, the first three empirical studies I conducted, assessed selective and executive attention in autism and in a fourth study I investigated the feasibility of a neurofeedback intervention. Specifically, in Chapter 2, I used behavioural markers of congruency effects to consider whether cognitive capacity would be increased for autistic people, analogous to the enhanced perceptual capacity previously reported. In Chapter 3, I investigated electrophysiological aspects of visual working memory capacity and filtering efficiency. The findings were further expanded upon in Chapter 4 by directly contrasting visual working memory capacity and perceptual capacity using electrophysiological markers. Finally, I sought to assess whether practical steps could be taken to address altered attention experienced by autistic adults. The feasibility of an online neurofeedback intervention was investigated to assess whether aspects of attention and mental health could be improved through the training programme (Chapter 5). The findings of the thesis were then summarised and further discussed, highlighting the contribution to the autism attention literature and offering practical recommendations to harness attentional strengths in autism