Chronometry of responses: Non parametric description of reaction times.

<p>Hazard (A) and speed-response (B) functions responses in AX, AY and BX trials are plotted for children (8–12 years old; gray line), adolescents (13–17; dotted line) and adults (18–22; black line). We display the central 80% of responses and curves are translated so that curves can be compared whenever they occurred in absolute time. The pattern of the remaining 20% of responses—the fastest 10% and slowest 10%–is described in the text. Markers on each line correspond to 25%, 50% and 75% of responses and help to verify such alignment. Insets show the complete curves and localize the subset of responses on absolute time scale. The hazard function insets contrast the empirical probability distribution functions for Target responses (positive direction) vs. Nontarget responses (for clarity, plotted in negative direction). Note the skewed profile that motivated the employed transformations for parametric analysis. Hazard functions on BX trials suggest a progression towards more prompt responding with age. Speed-response functions represent the instantaneous probability of Target response. Identical response biases at probe-onset and subsequent qualitatively similar information processing are evident for AX trials. For children, responses in AY trials are distinguishable for a protracted indecision period. Adults appear to maintain a clear Nontarget response bias throughout the whole response window as evident for both AY and BX trials.