Work

Examining the standard model of signal detection theory in motion discrimination

Year: 2016

Type: article

Abstract: We studied a fundamental assumption in signal detection theory that is applied to motion discrimination. Using random-dot motion stimuli of 100% coherence, it is natural to represent the two directions as two normal distributions. Then a same-different task and a forced-choice task should give rise to consistent d' estimates, because both tasks share the same underlying signal detection theory model. To verify this prediction, we used 4°, 8°, and 12° as the angular difference in motion discrimination. In a between-subjects design, we found the predicted result only with the 4° angular difference. With 8° and 12°, the estimated same-different d' was 32% greater than the two-alternative forced-choice d'. In a subsequent within-subject design with counterbalancing, the first half of the data confirmed this finding. Interestingly, there was now within-subject consistency. Namely, the second task's d' was comparable to the first task's, as if the first task's discrimination was carried over to the second task. This carryover effect diminished when the time gap between the two tasks was lengthened.

Source: Journal of Vision

DOI: 10.1167/16.7.9

Authors: Ju Liang, Yifeng Zhou, Zili Liu

Institutions: University of Science and Technology of China, University of California, Los Angeles

Language: English

Topic: Visual perception and processing mechanisms

Subfield: Cognitive Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $1,850

Funder: National Natural Science Foundation of China