A generalized magnitude system for space, time, and quantity? A cautionary note.

Area of Science:

• Cognitive Psychology
• Neuroscience

Background:

• The generalized magnitude system hypothesis proposes a common neural mechanism for representing various magnitudes like time, space, and quantity.
• Previous research, notably Xuan et al. (2007), suggested larger stimuli are perceived to last longer, supporting this hypothesis.
• It remains unclear if stimulus size truly affects duration perception or merely biases duration judgments.

Purpose of the Study:

• To investigate whether stimulus size influences perceived duration independently of decisional bias.
• To re-evaluate the generalized magnitude system hypothesis by employing a bias-free measure of duration perception.

Main Methods:

• Utilized duration "equality judgments" to measure perceived duration, a method proposed to be unconfounded by decisional bias.
• Contrasted findings with traditional "comparative judgments," which are susceptible to bias.
• Replicated the original Xuan et al. (2007) effect using comparative judgments to validate the methodology.

Main Results:

• Failed to find evidence that larger stimuli are perceived to last longer when using equality judgments.
• Replicated the original finding of larger stimuli seeming longer using bias-prone comparative judgments.
• Unexpectedly found that larger stimuli were judged as shorter in duration via equality judgments.

Conclusions:

• The claim that larger stimuli are perceived to last longer is not supported by bias-free duration equality judgments.
• Casts doubt on numerous behavioral studies relying on comparative judgments to support the generalized magnitude system hypothesis.
• Identified a novel source of decisional bias potentially affecting equality judgments themselves.