Uncertainty aversion predicts the neural expansion of semantic representations

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• Identifying stimulus meaning involves selecting correct semantic representations from many options.
• Reducing uncertainty can be achieved by differentiating semantic representations, expanding the semantic space.

Purpose of the Study:

• To test the semantic-expansion hypothesis.
• To investigate how uncertainty aversion influences semantic representations and related neural activity.
• To examine the behavioral consequences of semantic expansion.

Main Methods:

• Four experiments were conducted.
• Behavioral measures assessed semantic representations and interference.
• Neuroimaging (fMRI) examined brain activity in the left inferior frontal gyrus and ventromedial prefrontal cortex.

Main Results:

• Uncertainty-averse individuals showed more differentiated and separated semantic representations.
• Neural activity patterns in the left inferior frontal gyrus were more distant in uncertainty-averse individuals.
• The ventromedial prefrontal cortex showed enhanced sensitivity to semantic ambiguity in these individuals.
• Uncertainty-averse individuals exhibited reduced semantic interference and poorer generalization.

Conclusions:

• Uncertainty aversion drives the differentiation of semantic representations.
• This neural and behavioral differentiation enhances the identifiability of the world.
• The internal structure of semantic representations is key to organizing and understanding information.