Attractive Serial Dependence in the Absence of an Explicit Task

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Psychophysics

Background:

• Serial dependence describes how prior stimuli influence current perception, making them appear similar.
• The origin of serial dependence (perceptual vs. working memory/decision-based) remains debated.

Purpose of the Study:

• To investigate the neural basis and locus of serial dependence in numerosity perception.
• To differentiate between perceptual and decision-based accounts of serial dependence.

Main Methods:

• Utilized electroencephalography (EEG) to identify neural signatures of serial dependence.
• Conducted psychophysical experiments to measure behavioral biases in numerosity perception.

Main Results:

• Identified an early neural signature of serial dependence in the visual processing stream.
• Demonstrated an attractive, rather than repulsive, bias in numerosity perception due to prior stimuli.
• Showed that this bias occurs even without an explicit task, suggesting independence from decision processes.

Conclusions:

• Serial dependence in numerosity perception originates in early visual processing.
• This phenomenon is perceptual and independent of decision-making processes.
• Serial dependence likely serves to smooth neural noise, promoting perceptual continuity.