Journal: Nature Neuroscience

Article Title: Ripple-locked coactivity of stimulus-specific neurons and human associative memory

doi: 10.1038/s41593-023-01550-x

Figure Lengend Snippet: a , Cross-correlations between hippocampal ripples and ripples in extra-hippocampal MTL regions (temporal pole, amygdala, entorhinal cortex and parahippocampal cortex). Blue and gray numbers indicate the number of ipsilateral and contralateral channel pairs, respectively. Time 0, peak of hippocampal ripples. Cross-correlations are smoothed with a Gaussian kernel of 0.2-s duration and normalized by z -scoring cross-correlation values over time lags of ±0.5 s. Shaded region, mean ± s.e.m. across channel pairs. Black shading at top indicates cross-correlations from both ipsilateral and contralateral channel pairs significantly above 0 (one-sided cluster-based permutation test: P < 0.05). b , Time–frequency-resolved LFP power ( z -scored relative to the entire experiment) in extra-hippocampal MTL regions during hippocampal ripples. Power values are smoothed over time with a Gaussian kernel of 0.2-s duration. Time 0, ripple peak. Black contours, significantly increased power; white contours, significantly decreased power (two-sided cluster-based permutation tests: P < 0.025). c , Normalized LFP power extracted from the time periods of hippocampal ripples and averaged over time. Error bands, ±s.e.m. d , Single-neuron firing rates ( z -scored relative to the entire experiment) in hippocampal and extra-hippocampal regions during hippocampal ripples. Firing rates are smoothed over time with a Gaussian kernel of 0.2-s duration. Error bands, ±s.e.m. Blue and gray numbers indicate the number of ipsilateral and contralateral neuron–ripple channel pairs, respectively. Black shading at top indicates firing rates of ipsilateral and contralateral pairs significantly above 0 (one-sided cluster-based permutation test: P < 0.05). For region-specific and trial-phase-specific results, see Supplementary Figs. and . AMY, amygdala; CH, contralateral hemispheres; EC, entorhinal cortex; HC, hippocampus; IH, ipsilateral hemispheres; PHC, parahippocampal cortex; TP, temporal pole; X-Correlation, cross-correlation.

Article Snippet: The firing rate map was then smoothed with a Gaussian kernel (kernel size, 5; standard deviation, 1.5; using MATLAB’s ‘fspecial’ and ‘conv2’ functions).

Techniques: