Ψ adapts fast near to coarse threshold and then slowly and precisely to the threshold [23], like other adaptive procedures, see Fig. 1. |
Lapses and biases (e.g. serial dependencies [44]) affect adaptive procedures regarding the accuracy of threshold estimation. |
Threshold and slope of the psychometric function can be determined within the same measurement [23]. |
Lapses can have an impact rather on adaptive procedures than method of constant stimuli for example. |
Adaptive procedures are more time-efficient than the method of constant stimulus, in which the stimulus presentation is repeated at exactly the same intensity level multiple times. |
Lapses can occur for example due to pressing button wrongly [45], or not fixating on the stimulus by eye blinks or involuntary saccades. |
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To estimate the threshold and especially the slope, the Ψ algorithm needs a lot of computational power, especially RAM memory, for calculating the uncertainty [45]. |
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Calculations in real-time can unintentionally prolong the inter stimulus interval leading to longer duration of the measurement [45]. |