For each task-related neuron, we then performed a three-way neste

For each task-related neuron, we then performed a three-way nested Galunisertib ANOVA with target position, distance, and color combination as factors using mean activity within a 100 ms window starting from color-change

onset and slid along the trial in steps of 10 ms. If the neuron revealed a main effect of target position in at least three consecutive time bins, it was classified as a target-selection unit (Figure 3). (See Table S1 for the results.) The position (left or right) at which the unit produced the stronger response to the target was considered the neuron’s preferred location. In 64 out of the 122 target-selective neurons, we obtained data during the mapping task. We conducted in each unit a three-way ANOVA with target position, color, and motion direction as factors using mean firing rates within a 300 ms time window following stimulus onset. The proportion of neurons selective for each factor appears in Figure S2B. In order to determine whether such proportions

were significantly different from those expected by chance, we compared them against the ones obtained through a simulation procedure. We simulated for each neuron firing rates for the same amount of trials as during the task. These were obtained through an algorithm that chose for each condition n values (n, number of trials) from a normal distribution of responses with mean equal to the mean firing rate across the entire sample (over the find more same 300 ms following stimulus onset) and standard deviation equal to the average standard deviation across the sample. For the few cases of negative firing rates, the values were set to zero. We then performed the same three-way ANOVA on the simulated data. We ran the simulation and the ANOVA 100 times and obtained mean estimates of the proportions as mafosfamide well as confidence intervals. The mean proportions of cells that revealed a significant main effect were: 5.1% (color), 5.33% (side), and 5.25% (direction). Confidence intervals for all of them were between 4.5%

and 5.82%, considerably overlapping with the real data corresponding to color and direction, but not target position. To quantify the ability of target-distracter discrimination by the group of 122 dlPFC neurons showing differences in firing rate between targets and distracter at the preferred location, we applied a ROC analysis. This analysis takes into account not only the differences in mean response between two conditions but also the response variability of a neuron in individual trials (Thompson et al., 1996). A derived measurement, the auROC, represents the probability with which, on the basis of firing rates, an ideal observer can reliably identify the target in the presence of a distracter. A value of 0.5 indicates that a given firing rate could have been elicited with equal probability by the target or the distracter at the neurons’ preferred location. A value of 1.

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