Investigating mental simulation during sentence comprehension in aphantasia.

Area of Science:

• Cognitive Neuroscience
• Psychology of Language

Background:

• Aphantasia is characterized by the absence of conscious visual imagery.
• Debate exists on whether language comprehension relies on visual imagery or unconscious mental simulation.
• Investigating mental simulation in aphantasia offers insight into these processes.

Purpose of the Study:

• To directly test for mental simulation during sentence comprehension in individuals with aphantasia.
• To compare sentence-picture verification performance between aphantasics and controls.
• To determine if conscious visual imagery and unconscious mental simulation are distinct.

Main Methods:

• A sentence-picture verification task was employed with two experiments.
• Participants (aphantasics and controls) verified if an image matched a preceding sentence.
• Experiments manipulated implied color (Exp. 1) and distance (Exp. 2) in sentence-picture pairs.

Main Results:

• Both controls and aphantasics demonstrated a match effect for implied object color, indicating mental simulation.
• No evidence of mental simulation for implied distance was found in either group.
• Results suggest voluntary conscious imagery and involuntary unconscious simulation are separate cognitive processes.

Conclusions:

• Unconscious, involuntary mental simulation occurs during sentence comprehension, even in individuals with aphantasia.
• The findings support the dissociation between conscious visual imagery and non-conscious mental simulation.
• This research clarifies the mechanisms underlying language processing and imagery.