13.1 Experiment: Estimating Visual Perception Thresholds with an Random-Dot Kinematogram (RDK) Task

Present RDK trials with an adaptive staircase procedure. Trials begin with a high coherence level (easy, close to 1), and the coherence level on subsequent trials depends on performance: the task becomes more difficult after N correct responses, and becomes less difficult after N incorrect responses. This is used to estimate the coherence values that correspond to a particular performance level (e.g. 70% correct responses) for each participant. There are separate adaptive tracks and threshold estimates for two different conditions: low contrast (more similar dot and background colors) and high contrast (less similar colors).

At the end of the task, a performance chart is shown with the conherence values across trials for the two conditions (low and high contrast).

Key topics covered: - Using an adaptive staircase procedure with the jsStaircase library - Adding an interactive performance summary graph with Google Charts: https://developers.google.com/chart

Other topics covered: - jsPsych data manipulation