As research into age- and AD-related hyperactivation has traditionally employed fMRI [1], it is less clear what electrophysiological milieu it arises from and how hyperactivation can be gauged in humans with EEG. An emerging field of research suggests that the aperiodic exponent of the EEG power spectrum could be a general indicator of the excitation-inhibition-balance of the brain [2,3]. Correspondingly, a lower aperiodic exponent, i.e., a more excited brain state, during resting is consistently observed in older individuals and may mediate age-related working memory deficits [4]. Furthermore, the aperiodic exponent is dynamically modulated by task demand making it a promising target for investigating age-related hyperactivation during a working memory task [5,6,7].
Since the aperiodic exponent is also modulated by activity of the autonomic nervous system [8,9,10], at least in the resting state, a broad, multimodal perspective is needed that considers factors such as breathing [11, 12], in order to investigate the potential recruitment of compensatory neural resources that could manifest as age-related hyperactivation.
Accordingly, we plan to investigate a sample of older individuals who have undergone thorough phenotyping (particularly with regard to brain pathology) while at rest and while performing a working memory task involving varying levels of demand, in order to generate a better understanding of the milieu from which age-related hyperactivation arises.
Find out more about the working group by clicking here.
References
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