Figure 1

FFT vs AR power spectra & coherence vs rPDC: Effect of age on EEG power and connectivity in WT mice. (a) EEG power (as log arbitrary units [a.u.], means + SEM) illustrated over the 1–50 Hz range for mice aged 5 m (black) and 13 m (red). Left: FFT-based power spectra for each recording site, right: corresponding spectra calculated using autoregressive spectral estimation (AR). Asterisks on plots provide a p-value summary for the effect of age (*p < 0.05, **p < 0.01, ***p < 0.001). (b) Mean “classical” coherence strength [a.u., left column] observed between all possible channel pairs over the 1–50 Hz range for mice aged 5 m (black) and 13 m (red). Corresponding rPDC strength [a.u.] over the same frequency range for all possible channel pairs and directions of coherence are depicted in the middle and right columns. Pictograms on the left illustrate which channel pairs are analysed in each row. Plot titles indicate compared channels and, where applicable, direction of coherence. R.PFC = right prefrontal, R.H = right parietal (hippocampus), L.H = left parietal (hippocampus). Blue lines = 95% confidence limit. Lightly coloured lines indicate the confidence interval of the group means. Significant differences between age groups are illustrated for individual frequency bands (*p < 0.05).