Attractive serial dependence arises during decision-making.

Area of Science:

• Cognitive Neuroscience
• Human Memory Research
• Neural Basis of Perception

Background:

• Stimulus history influences recall, causing attractive or repulsive serial dependence.
• The timing and neural mechanisms of attractive versus repulsive biases remain unclear.
• A two-stage model suggests adaptation causes repulsive encoding bias, countered by attractive decision-stage bias.

Purpose of the Study:

• To investigate the temporal dynamics and neural underpinnings of attractive and repulsive serial biases.
• To determine if the discrepancy between neural encoding and behavioral recall biases is resolved during decision-making.
• To test the predictions of a two-stage model of serial dependence.

Main Methods:

• Multivariate decoding of human magnetoencephalography (MEG) data during a working memory task.
• Analysis of neural representations during encoding and recall periods.
• Replication using an independent electroencephalogram (EEG) experiment.

Main Results:

• Neural representations showed an attractive bias during the recall period, supporting the two-stage model.
• Repulsive behavioral biases were associated with an early, repulsive neural bias during encoding.
• An attractive neural bias during recall was consistently replicated across MEG and EEG experiments.

Conclusions:

• Attractive serial dependence originates during the decision-making stage, not encoding.
• Repulsive serial dependence appears to be incorporated during the stimulus encoding phase.
• Decision-making priors are updated by the prior trial's target, but not other stimuli.