Can expectation suppression be explained by reduced attention to predictable stimuli?

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• The expectation-suppression effect, characterized by diminished neural responses to anticipated stimuli, is often interpreted as evidence for reduced prediction errors within predictive coding frameworks.
• This interpretation is prevalent in studies of the visual cortex.

Purpose of the Study:

• To challenge the prevailing view that expectation suppression solely reflects reduced prediction errors.
• To propose and discuss an alternative explanation: expectation suppression as a consequence of altered attention allocation.
• To highlight the need for research differentiating the neural mechanisms of attention and surprise.

Main Methods:

• The study primarily relies on a theoretical discussion and synthesis of existing findings, particularly from visual cortex research.
• It proposes experimental approaches to distinguish between attention-based and prediction error-based explanations.

Main Results:

• The core argument posits that reduced neural responses to predictable stimuli can be explained by a decrease in attention driven by stimulus saliency.
• This challenges the direct link between expectation suppression and prediction error reduction.

Conclusions:

• Expectation suppression may not be a definitive marker of reduced prediction errors.
• Attention allocation, specifically reduced saliency-driven attention to expected stimuli, offers a viable alternative explanation.
• Future research should focus on the qualitative differences in how attention and surprise modulate neural activity to resolve this debate.