Figure 6. ROC analysis and neurometric function.

(a) Distribution of responses from an example neuron in response to preferred (red bars) and orthogonal (blue bars) orientations at five contrast levels. (b) Receiver operating characteristic (ROC) curves for the responses to the five contrasts shown in (a). For each ROC curve, the probability that the response to the preferred orientation exceeds a given criterion value is plotted against that to the orthogonal orientation. (c) Neurometric function for the responses shown in (a). The ROC area for each contrast was computed from the corresponding ROC curve. (d–f), same as described in (a–c) for another example neuron.