Working Memory Related Functional Connectivity in Adults with ADHD and Associated Training Effects
Poster No:
422
Submission Type:
Abstract Submission
Authors:
Tuija Tolonen1, Sami Leppämäki2, Kimmo Alho1, Pekka Tani3, Anniina Koski3, Matti Laine4, Juha Salmi5
Institutions:
1University of Helsinki, Helsinki, Finland, 2Terveystalo Healthcare, Helsinki, Finland, 3Helsinki University Hospital, Helsinki, Finland, 4Åbo Akademi University, Turku, Finland, 5Aalto University, Espoo, Finland
First Author:
Co-Author(s):
Introduction:
Working memory (WM) deficits are amongst the most prominent cognitive impairments in attention deficit hyperactivity disorder (ADHD; Alderson et al. 2013). While functional connectivity is a prevailing approach in brain imaging of ADHD, the network level alterations in synchronized activation between brain areas and their malleability by cognitive training are not well known. Here, we studied WM related differences in whole brain functional connectivity between adults with and without ADHD. In addition, we conducted a randomized controlled trial examining the effects of WM training on functional connectivity patterns in a trained and an untrained task in adults with ADHD. This study extends our previous findings with the same sample, showing reduced structural connectivity (Tolonen et al. 2023) and a training-related restoration of regional brain activity (Salmi et al. 2020) in adults with ADHD.
Methods:
41 adults with ADHD and 36 neurotypical (NT) controls matched in age, gender, handedness, and education level performed visuospatial and digit n-back WM tasks (levels from 0-back to 3-back) during functional magnetic resonance imaging (fMRI). The adults with ADHD continued to a 5-week randomized controlled WM training trial with 20 participants practicing a dual n-back task and 18 adults performing an active control task, after which the fMRI measurement was repeated. Functional connectivity of the whole brain was measured by calculating pairwise correlations of mean brain activity in 164 pre-defined parcels (Destrieux et al. 2010; Patenaude et al. 2011). Subnetworks indicating group differences and training effects (on a trained visuospatial task and an untrained digit task) on functional connectivity were identified with Network-Based Statistic (Zalesky et al. 2010), a data-driven method for clustering single connected components. A post-hoc analysis further examined whether the subnetworks differentiating adults with and without ADHD respond to training.
Results:
Adults with ADHD had decreased functional connectivity in wide-spread networks compared with the NT controls during both visuospatial and digit n-back tasks (p = .03 and p < .01, respectively, FWE-corrected; Figure 1). The networks encompassed prefrontal, temporal, parietal and occipital cortices, the insula, the cingulate cortex, the cerebellum, and subcortical structures such as the thalamus and the striatum, areas consistently associated with WM (Yaple et al. 2019). The network related to digit (verbal) n-back task was overall larger and especially included areas related to language processing. We found no group × time interaction effects of WM training surviving correction for multiple comparisons.
Conclusions:
Our results indicate that large-scale abnormalities in functional networks underlie deficits in verbal and visuospatial WM commonly faced in ADHD. However, their plasticity by WM training may be restricted to regional level.
Disorders of the Nervous System:
Neurodevelopmental/ Early Life (eg. ADHD, autism) 1
Learning and Memory:
Neural Plasticity and Recovery of Function
Working Memory
Modeling and Analysis Methods:
Connectivity (eg. functional, effective, structural)
fMRI Connectivity and Network Modeling 2
Keywords:
Attention Deficit Disorder
Learning
Memory
Other - connectivity
1|2Indicates the priority used for review
Provide references using author date format
Destrieux, C. (2010), ‘Automatic parcellation of human cortical gyri and sulci using standard anatomical nomenclature’, NeuroImage, vol. 53, no. 1, pp. 1–15.
Patenaude, B. (2011), ‘A Bayesian model of shape and appearance for subcortical brain segmentation’, NeuroImage, vol. 56, no. 3, pp. 907–922.
Salmi, J. (2020), ‘Working memory training restores aberrant brain activity in adult attention-deficit hyperactivity disorder’, Human Brain Mapping, vol. 41, no. 17, pp. 4876–4891.
Tolonen, T. (2023), ‘Abnormal wiring of the structural connectome in adults with ADHD’, Network Neuroscience, vol. 7, no. 4, pp. 1302–1325.
Yaple, Z.A. (2019), ‘Meta-analyses of the n-back working memory task: fMRI evidence of age-related changes in prefrontal cortex involvement across the adult lifespan’, NeuroImage, vol. 196, pp. 16–31.
Zalesky, A. (2010), ‘Network-based statistic: Identifying differences in brain networks’, NeuroImage, vol. 53, no. 4, pp. 1197–1207.