Revista de la Facultad de Medicina (Jan 2017)
Cognition, electroencephalographic response and their relation with heart rate variability
Abstract
Introduction: The frontal cortex has a greater theta activity during cognitive observation and learning processes. Objective: To establish the relation between orbitofrontal electroencephalographic activity and the autonomic nervous system in cognitive processes. Materials and methods: 20 men and 19 women with a mean age of 21.2 (±2.32) were evaluated by electroencephalography (EGG) FP1-T3, FP2-T4 and electrocardiography (ECG) to determine heart rate (HR) and heart rate variability (HRV). The evaluation was made in five phases during rest, observation, memory, concentration and playing conditions. EGG and ecg signals were analyzed in the frequency domain using the Fast Fourier Transform (FFT). The differences between the variables found during each phase were established through a two-way ANOVA. Results: When compared to rest conditions, all phases showed an increase of theta activity of the EGG (p <0.01), as well as of the low frequencies LF (p <0.01) and HR (p <0.01), and a decrease in the high frequency HF (P <0.01). In addition, there was an inverse correlation between theta activity and HF power (r=-0.86). Conclusions: The data showed a reduction in parasympathetic activity and an increased sympathetic activity associated with theta activity in the orbitofrontal cortex, using a connection with the central nucleus of the amygdala.
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