Neuronal responsive enhancement to salient stimuli.

<p>(A) Neuronal responsive enhancement to a warning stimulus (WS, pink color epoch) after an erroneous behavioral response: firing rate was enhanced during trials following an error response (thin black trace). (B) Evaluation-related (orange color epoch) ACC neuronal activity is biased towards error processing: neuronal activation is strong when time-locked to the error signal (thick black trace) but slight when locked to reward delivery (thick red trace) C) Firing rate changes of the same CMAr neuron during both the warning stimulus (left) and evaluative (right) period of repeated trials: post-error successful trials. Coloring as in C.</p

Mean firing rates in the recorded neuronal population.

<p>Right bars: increased firing rate for negative feedback (E) in comparison with positive feedback (S). Middle bars: warning stimulus (WS) responsiveness is enhanced after an erroneous behavioral response (E+1); left bars show virtually identical mean firing rates for inter-trial activity (Iti) measured immediately prior to WS presentation.</p

Adaptation to error.

<p>(A) Pooled data showing a lower behavioral error rate in post-error trials than in post-success trials (p<0.001). * <i>P</i><0.01; ** <i>P</i><0.001. (B) Based on trial-by-trial analysis, WS-related activity was normalized using the response range of each cell (Fi-Fmax/Fmax-Fmin), showing that the WS spike rate correlates inversely with error probability. Normalized activity was plotted against error probability for a corresponding bin size of neuronal activity (bin size = 0.05). Fi, frequency for a given trial; Fmax, maximum rate; Fmin, minimum rate.</p

Bimodal neurons.

<p>(A) Schematic representation of the behavioral task. Trials always began with a warning stimulus (WS; black circle) and ended with an evaluative period (Trial outcome). Each trial followed the previous one after a 3 sec inter-trial interval (Iti). (B) Firing rate changes in a single ACC neuron during both the warning-stimulus (pink color) and the evaluative period (orange color) of two sequential trials. Each thin vertical bar represents an individual action potential and each curve represents the instantaneous firing rate of the neuron. The top panel shows post-success erroneous trials; the bottom panel, post-error successful trials. Coloring as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006240#pone-0006240-g003" target="_blank">Figure 3</a>.</p

Stroop-like task (SLT) in monkey.

<p>After a 3000 ms rest period, a warning stimulus (black circular cue) was presented for 500 ms in the center of a video screen. The SLT target then appeared, followed by a drop of juice (successful response) or a black screen (erroneous response). Each stimulus interval was randomized between 500 and 1000 ms.</p

Cumulative number of inappropriate line crossings (ILC) for the 14 subjects in the last hour of the 3 nocturnal driving sessions (short, intermediate and long durations of driving), as well as the ILC for the reference drive (9–10 pm of the long drive).

<p>Statistical analyses refer to Incidence rate ratios (IRR) with 95% confidence intervals (CI) using the short drive and the 9–10 pm drive as reference (See section <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003493#s3" target="_blank">results</a>). * P<.05. ** P<.001.</p

Design of the protocol representing the sleep-wake period and the duration of each nocturnal driving session (short, intermediate and long durations of driving).

<p>Design of the protocol representing the sleep-wake period and the duration of each nocturnal driving session (short, intermediate and long durations of driving).</p

Fatigue (VAS) scores after the last hour of driving (Mean±SD) and Karolinska Sleepiness Scale (KSS) scores before the last hour of driving (Mean±SD) in the reference session and in the 3 nocturnal driving sessions.

<p>The asterisks refer to significant differences between the 3 nocturnal driving sessions (short, intermediate and long durations of driving) and the reference. The square refers to a significant difference between 9 pm–5 am and 1–5 am sessions.</p>*<p>P<.01.</p>**<p>P<.001.</p>□<p>P<.01.</p

α-flupentixol alters the firing patterns of substantia nigra <i>pars reticulata</i> neurons.

<p>(A and B) Sections of extracellular recordings of action potentials, before and after injection respectively, showing that α-flupentixol reduced the firing rate and made the pattern irregular. (C and D) Interspike interval histograms, (E and F) density histograms, respectively before and after α-flupentixol injection confirming the disorganization of the firing pattern induced by α-flupentixol in the same neuron.</p

α-flupentixol induces changes of electrical activity of subthalamic nucleus neurons.

<p>(A) A representative example of a firing rate histogram showing the inhibitory effect of α-flupentixol on STN neuronal activity. (B) α-flupentixol decreases the firing rate of all STN neurons tested (n = 9/9), and (C) increases the coefficient of variance of the interspike interval (ISI) (One-way ANOVA with repeated measures followed by the Dunnett's test, *<i>p</i><0.05, **<i>p</i><0.01). Arrows indicate the time at which α-flupentixol was administred.</p