Stimulus expectations do not modulate visual event-related potentials in probabilistic cueing designs

Area of Science:

• Neuroscience
• Cognitive Science
• Visual Perception

Background:

• Predictive coding models suggest fulfilled expectations reduce neural responses (expectation suppression) and surprising events increase them in the visual system.
• Existing evidence for expectation suppression in the visual system is limited, especially when controlling for confounding factors.
• Previous studies observed surprise effects in blood oxygen level dependent (BOLD) signals but not electrophysiological measures.

Purpose of the Study:

• To rigorously test for expectation suppression and surprise effects in the human visual system using electroencephalography (EEG).
• To investigate whether fulfilled perceptual expectations lead to reduced neural signaling, as predicted by some influential models.

Main Methods:

• A predictive cueing experiment was conducted with 48 participants, involving learning cue-face associations.
• Electroencephalographic (EEG) data were recorded while participants viewed faces associated with expected (90%), neutral (50%), or surprising (10%) cues.
• Univariate analyses of face-evoked event-related potentials (ERPs) and multivariate pattern analysis were employed.

Main Results:

• No significant differences in face-evoked ERPs were found across expected, neutral, and surprising conditions.
• Bayes factors consistently supported the null hypothesis, indicating no evidence for expectation suppression or surprise effects in ERPs.
• Robust stimulus repetition effects were observed, but no above-chance classification of expected versus surprising face-evoked ERPs was achieved.

Conclusions:

• The findings do not support predictive coding models that posit reduced prediction error signaling when perceptual expectations are met.
• Results suggest that alternative predictive processing models, which do not rely on prediction error signaling for expectation-related phenomena, may be more suitable for explaining visual system activity.
• This study underscores the need for further research into the neural mechanisms underlying expectation and prediction in visual perception.