Integrating "brain" and "body" measures: correlations between EEG and metabolic changes over the human lifespan.
OBJECTIVE
This study investigated the relationship between electroencephalograph (EEG) power and basal metabolic rate (BMR) over the human lifespan, to better understand the mechanisms involved in the decline of neural activity with age.


METHODS
Eyes-open EEG power was calculated in standard frequency bands and averaged across recording sites in 1831 healthy subjects aged 6 to 86 years, from the Brain Resource International Database. In a subset of 175 subjects, structural MRI scans were also undertaken to determine the role of grey matter. Cerebral metabolic rate (CMR) was estimated using two models of EEG power, based on: (1) normalization of BMR by total body mass, and (2) scaling by cortical grey matter.


RESULTS
Regression analysis revealed a linear relationship between the CMR estimates and EEG power under both models. In the full sample, CMR explained 65% of the variance in delta power, and 53% of the variance in theta power over the age span.


CONCLUSIONS
The results demonstrate that the large EEG signals in early childhood are associated with a higher BMR during that age.


CONCLUSIONS
The use of cross-modal measurements in this study highlights the utility of capturing data in an integrative framework to reveal fundamental physiological relationships.
Boord
Peter R
PR
The Brain Dynamics Center, Westmead Millennium Institute, Westmead Hospital and Western Clinical School, University of Sydney, Westmead Hospital, Westmead, NSW 2145, Australia. peter_boord@brainresource.com
Rennie
Chris J
CJ
Williams
Leanne M
LM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015992:Body Mass Index; D001837:Body Weights and Measures; D001921:Brain / Q000378:metabolism* / Q000502:physiology*; D002648:Child; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical