S140 High frequency eeg oscillations in cognitive decline and aging

Abstract

Objectives Higher cognitive functions depend critically on synchronized network activity in the gamma range (30–100 Hz), which results from activity of fast spiking (FS) parvalbumin positive (PV) interneurons. EEG oscillation in the gamma band is linked to sensory perception and integration, learning, memory and attention. Distinct alterations of these oscillatory signals have been discovered in subjects with normal healthy aging. The objective of our study was to examine whether changes in EEG gamma power accompany changes in cognitive function in otherwise healthy individuals. Methods In our presentation I would like to focus on a large Danish birth cohort of males born in 1953, which were followed longitudinally throughout their life course. Our database contains all information about cognitive development, health and environmental issues. We used visual, auditory and bi-modal steady state evoked responses to generate EEG gamma activity that was correlated to cognitive performance. Results Our data suggests that the ratio between EEG gamma and alfa power decrease with age. Subjects with reduced cognitive performance have lower EEG gamma power compared to persons with normal cognition. Furthermore we discuss how the response after visual stimulation is altered when a competing second stimulus is presented at the same time. Our data suggests that steady state responses may be predictors of intelligence, working performance and that the EEG gamma power response correlates with cognitive test results. Conclusions We conclude that steady state evoked EEG gamma responses may be useful correlates of intelligence and cognitive performance.