Fig. 2

A–D Local field potential (LFP) responses to presented vs. omitted stimuli, normalised to pre-stimulus baseline (n = 6 penetrations). E–H Analogue multiunit activity (AMUA) responses to presented vs. omitted stimuli, normalised to pre-stimulus baseline (n = 6 penetrations). A, E Time courses of responses (normalised to pre-stimulus baseline) evoked by presented stimuli (solid lines) relative to stimulus presentation (noise bursts immediately preceding omissions), and by stimulus omissions (dashed lines) relative to the expected but omitted stimulus onset. Dark blue, blue, and light blue lines correspond to stimulus presentation rates of 2, 3, and 4 Hz. Shaded areas represent standard error of the mean (SEM) across channels. B, F Peak amplitudes (Y-axis) and latencies (X-axis) of each penetration, averaged across analysed channels. Filled circles: stimulus-evoked responses; empty circles: omission responses; colours as above. C, G Peak amplitude comparison of stimulus-evoked (filled bars) and omission responses (empty bars) across the three stimulus presentation rates. Error bars represent SEM across channels. Please note that single channels are presented in B and F. D, H Peak amplitude comparison of stimulus-evoked vs. omission responses across the three stimulus presentation rates (filled/empty bars as above). Error bars represent SEM across channels. I Baseline-corrected peristimulus time histograms (PSTHs), quantifying single-unit spiking activity responses to noise bursts (left panel) and omitted stimuli (right panel). Colours as in A and E. Shaded areas represent SEM across units. J Multiunit PSTHs. Legend as in I