Figure 4 Basal forebrain categories of task-phase-specific firing have counterparts with negatively correlated patterns. (A) For each of the 60 categories of task-phase-specific
basal forebrain (BF) firing patterns, the correlation of the mean firing pattern for ... The foregoing this website results suggest that, for complex behavioral tasks, BF neurons are organized into distinct groups by virtue of the anatomical organization of their local interconnections, by their extrinsic afferents, or both. Irrespective of whether such patterning reflects learning processes, if such a highly organized pattern of connectivity exists, then variation in task-phase-specific firing rates for any pair of neurons should tend to follow the degree to which their mean firing patterns are
similar or dissimilar. Evidence for this was obtained in a 鈥渘oise correlation鈥� analysis summarized in Figure 鈥婩igure5.5. Noise correlation determines, for any two neurons, the extent of any relation between their respective deviations from mean firing rates on each trial (and, in this case, for each task phase; Zohary et al., 1994; Kargo and Nitz, 2004). In the example given in Figure 鈥婩igure5A,5A, the task-phase-specific firing rates for two neurons across three succeeding trials are appended across the x-axis (dashed lines in upper and middle panels, thin vertical lines separate trials). For comparison, the mean cross-trial firing rates for the same neurons are repeated (full lines). The lower panel depicts the subtraction of these cross-trial mean rates from Bilirubin oxidase the firing rates for each phase of each individual trial.
For this pair of neurons, the mean firing rate patterns are highly similar (r = 0.87) as are patterns of deviation from their means (r = 0.76 for the trials shown, r = 0.60 across all trials). That is, the spike rate deviations from mean cross-trial rates are not stochastic, but reflect co-variation of the neuron pair's spiking responses. Figure 5 Noise correlation among basal forebrain neurons having similar or dissimilar firing patterns. (A) Upper and middle panels depict max-normalized firing rates for two simultaneously-recorded basal forebrain neurons across three consecutive trials (dashed ... For all neuron pairs having significant correlation in their mean firing rate vectors Apoptosis inhibitor (鈥渟ignal鈥� correlations >0.345 or <鈭�0.345 using 54-bin rate vectors), the statistical significance of their noise correlation was examined by comparing it with that obtained when trial orders were shuffled for one of the two neurons. For each pair, the noise correlation expected by chance was taken as the mean of 100 such randomizations of trial identity. Across 14,020 pairs having positive signal correlations, 62% exhibited noise correlation values two standard deviations or more greater than that expected by chance.</div>
basal forebrain (BF) firing patterns, the correlation of the mean firing pattern for ... The foregoing this website results suggest that, for complex behavioral tasks, BF neurons are organized into distinct groups by virtue of the anatomical organization of their local interconnections, by their extrinsic afferents, or both. Irrespective of whether such patterning reflects learning processes, if such a highly organized pattern of connectivity exists, then variation in task-phase-specific firing rates for any pair of neurons should tend to follow the degree to which their mean firing patterns are
similar or dissimilar. Evidence for this was obtained in a 鈥渘oise correlation鈥� analysis summarized in Figure 鈥婩igure5.5. Noise correlation determines, for any two neurons, the extent of any relation between their respective deviations from mean firing rates on each trial (and, in this case, for each task phase; Zohary et al., 1994; Kargo and Nitz, 2004). In the example given in Figure 鈥婩igure5A,5A, the task-phase-specific firing rates for two neurons across three succeeding trials are appended across the x-axis (dashed lines in upper and middle panels, thin vertical lines separate trials). For comparison, the mean cross-trial firing rates for the same neurons are repeated (full lines). The lower panel depicts the subtraction of these cross-trial mean rates from Bilirubin oxidase the firing rates for each phase of each individual trial.
For this pair of neurons, the mean firing rate patterns are highly similar (r = 0.87) as are patterns of deviation from their means (r = 0.76 for the trials shown, r = 0.60 across all trials). That is, the spike rate deviations from mean cross-trial rates are not stochastic, but reflect co-variation of the neuron pair's spiking responses. Figure 5 Noise correlation among basal forebrain neurons having similar or dissimilar firing patterns. (A) Upper and middle panels depict max-normalized firing rates for two simultaneously-recorded basal forebrain neurons across three consecutive trials (dashed ... For all neuron pairs having significant correlation in their mean firing rate vectors Apoptosis inhibitor (鈥渟ignal鈥� correlations >0.345 or <鈭�0.345 using 54-bin rate vectors), the statistical significance of their noise correlation was examined by comparing it with that obtained when trial orders were shuffled for one of the two neurons. For each pair, the noise correlation expected by chance was taken as the mean of 100 such randomizations of trial identity. Across 14,020 pairs having positive signal correlations, 62% exhibited noise correlation values two standard deviations or more greater than that expected by chance.</div>