Figure 3. Results - performance.

(a). Results for one observer. Each point represents measured discrimination performance (probability correct) for a given signal-to-noise ratio and condition. Two psychometric functions, one per condition, are fitted to measure performance. The psychometric functions are distinct, indicating that performance was higher in the TC condition. (b). Aggregated results. 75% thresholds are estimated from performance data separately for the two conditions. A higher threshold is indicative of lower performance. Error bars are standard errors obtained from a parametric bootstrap [32].