Independent short- and long-term dependencies in perception

Area of Science:

• Cognitive Psychology
• Computational Neuroscience
• Visual Perception

Background:

• Perception is influenced by stimulus history, leading to biases.
• Central-tendency bias (CTB) and serial dependence (SD) are known perceptual biases.
• Research on CTB and SD has largely progressed independently, despite correlated stimulus statistics.

Purpose of the Study:

• To compare central-tendency bias (CTB) and serial dependence (SD) in color and line length perception.
• To investigate the role of elapsed time versus intervening stimuli in serial dependence.
• To determine if CTB and SD independently influence perceptual judgments.

Main Methods:

• Observers performed a delayed-matching task for color hue and line length.
• Psychometric functions and generalized linear mixed models were used to estimate biases.
• Two interstimulus intervals were employed to differentiate time and stimulus count effects.

Main Results:

• Both recent stimulus history (SD) and cumulative average (CTB) biases were observed for color and line length.
• The strength and pattern of biases varied depending on whether both CTB and SD were considered.
• For SD, the number of intervening stimuli was more critical than elapsed time.

Conclusions:

• Serial dependence (SD) and central-tendency bias (CTB) are independent factors influencing perceptual judgments.
• Neither SD nor CTB is an artifact of the other.
• Failure to account for both biases can lead to misinterpretations in perceptual research.