FV 10. Motor imagery supported by neurofeedback: Age-related changes in EEG and fNIRS lateralization patterns. Issue 9 (September 2016)

• Record Type: Journal Article
• Authors: Zich, C.; Debener, S.; Chen, L.-C.; Kranczioch, C.
• Is Part Of: Clinical neurophysiology. Volume 127:Issue 9(2016:Sep.)
• Page Start: e215
• Publication Date: 2016-09
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2016.05.027
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : Motor imagery (MI) supported by neurofeedback has been suggested as a promising add-on therapy to facilitate motor recovery after stroke. Though the main target group for such an intervention are elderly patients, research so far is largely focused on young, healthy adults. We therefore examined in two experiments the influence of age on the neural correlates of motor imagery (MI) in a real-time electroencephalogram (EEG) neurofeedback framework. In a first experiment MI-induced activity was studied in MI and neurofeedback naïve young ( N = 39; 18–30 years) and elderly ( N = 36; >55 years) healthy adults. MI was supported by EEG feedback, and feedback was based on features extracted from the mu and beta frequency bands. Electromyogram (EMG) data were recorded concurrently to control for executed movements. During MI the group of older participants was characterized by a significantly reduced lateralization of EEG event-related desynchronization (ERD), mainly due to stronger ipsilateral ERD, and, in consequence, reduced classification accuracies. EEG-based neurofeedback resulted in a task-related activity increase irrespective of age. Aim of the second experiment was to replicate and validate these results. To this end, EEG was combined with simultaneous functional near-infrared spectroscopy (fNIRS). MI-induced activity was studied in a new sample of MI and neurofeedback naïve young ( N = 19; 18–30 years) and elderly ( N = 18; >55 years) healthy adults. As before, MI was supported by EEG feedback based on features extracted from mu and beta frequency bands and EMG data were recorded concurrently to control for executed movements. The observation of a reduced lateralization due to stronger ipsilateral ERD could be replicated. Furthermore, fNIRS deoxygenated haemoglobin concentration changes confirmed this less lateralized pattern in the elderly. For both age groups the EEG-based neurofeedback resulted in a task-related increase in ERD and fNIRS activity. The reduction of lateralized brain activity during MI in the elderly is in good agreement with previous research showing similar age-related changes during MI and other cognitive tasks. This finding is in line with the general view that compensatory processes are recruited to counteract neurodegenerative changes during healthy ageing. However, these age-related changes did not compromise the responsiveness to neurofeedback. We therefore conclude that the potential benefit of a neurofeedback supported modulation of brain activity is preserved in the elderly.