Working memory training in congenitally blind individuals results in an integration of occipital cortex in functional networks

TY - JOUR

T1 - Working memory training in congenitally blind individuals results in an integration of occipital cortex in functional networks

AU - Gudi-Mindermann, Helene

AU - Rimmele, Johanna M

AU - Nolte, Guido

AU - Bruns, Patrick

AU - Engel, Andreas K

AU - Röder, Brigitte

N1 - Copyright © 2018 Elsevier B.V. All rights reserved.

PY - 2018/8/1

Y1 - 2018/8/1

N2 - The functional relevance of crossmodal activation (e.g. auditory activation of occipital brain regions) in congenitally blind individuals is still not fully understood. The present study tested whether the occipital cortex of blind individuals is integrated into a challenged functional network. A working memory (WM) training over four sessions was implemented. Congenitally blind and matched sighted participants were adaptively trained with an n-back task employing either voices (auditory training) or tactile stimuli (tactile training). In addition, a minimally demanding 1-back task served as an active control condition. Power and functional connectivity of EEG activity evolving during the maintenance period of an auditory 2-back task were analyzed, run prior to and after the WM training. Modality-specific (following auditory training) and modality-independent WM training effects (following both auditory and tactile training) were assessed. Improvements in auditory WM were observed in all groups, and blind and sighted individuals did not differ in training gains. Auditory and tactile training of sighted participants led, relative to the active control group, to an increase in fronto-parietal theta-band power, suggesting a training-induced strengthening of the existing modality-independent WM network. No power effects were observed in the blind. Rather, after auditory training the blind showed a decrease in theta-band connectivity between central, parietal, and occipital electrodes compared to the blind tactile training and active control groups. Furthermore, in the blind auditory training increased beta-band connectivity between fronto-parietal, central and occipital electrodes. In the congenitally blind, these findings suggest a stronger integration of occipital areas into the auditory WM network.

AB - The functional relevance of crossmodal activation (e.g. auditory activation of occipital brain regions) in congenitally blind individuals is still not fully understood. The present study tested whether the occipital cortex of blind individuals is integrated into a challenged functional network. A working memory (WM) training over four sessions was implemented. Congenitally blind and matched sighted participants were adaptively trained with an n-back task employing either voices (auditory training) or tactile stimuli (tactile training). In addition, a minimally demanding 1-back task served as an active control condition. Power and functional connectivity of EEG activity evolving during the maintenance period of an auditory 2-back task were analyzed, run prior to and after the WM training. Modality-specific (following auditory training) and modality-independent WM training effects (following both auditory and tactile training) were assessed. Improvements in auditory WM were observed in all groups, and blind and sighted individuals did not differ in training gains. Auditory and tactile training of sighted participants led, relative to the active control group, to an increase in fronto-parietal theta-band power, suggesting a training-induced strengthening of the existing modality-independent WM network. No power effects were observed in the blind. Rather, after auditory training the blind showed a decrease in theta-band connectivity between central, parietal, and occipital electrodes compared to the blind tactile training and active control groups. Furthermore, in the blind auditory training increased beta-band connectivity between fronto-parietal, central and occipital electrodes. In the congenitally blind, these findings suggest a stronger integration of occipital areas into the auditory WM network.

KW - Adult

KW - Blindness

KW - Brain

KW - Brain Mapping

KW - Electrocardiography

KW - Female

KW - Functional Laterality

KW - Humans

KW - Learning

KW - Male

KW - Memory, Short-Term

KW - Middle Aged

KW - Occipital Lobe

KW - Touch

KW - Visually Impaired Persons

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1016/j.bbr.2018.04.002

DO - 10.1016/j.bbr.2018.04.002

M3 - SCORING: Journal article

C2 - 29655595

VL - 348

SP - 31

EP - 41

JO - BEHAV BRAIN RES

JF - BEHAV BRAIN RES

SN - 0166-4328

ER -