Evidence for visual simulation during sign language processing

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Linguistics

Background:

• Spoken language comprehension involves perceptual simulation, activating sensorimotor states for semantic information.
• It remains unknown if sign languages, a manual-visual modality, also engage perceptual simulation.

Purpose of the Study:

• To investigate whether processing sign language activates perceptual simulation in the visual system.
• To determine if this visual simulation is specific to fully developed sign language users.

Main Methods:

• Utilized continuous flash suppression (CFS) to measure detection sensitivity to images.
• Compared detection of visual images after processing spoken words versus sign language signs.
• Assessed participants including deaf signers and hearing nonsigners.

Main Results:

• Processing signs significantly boosted the detection of congruent visual images in signers.
• This boost in visual processing was specific to signers, not observed in hearing nonsigners.
• The effect of signs on detection was independent of iconicity.

Conclusions:

• Sign language comprehension relies on visual perceptual simulation, similar to spoken language.
• Visual simulation in language processing is a foundational mechanism, independent of modality (sign vs. speech) or iconicity.
• Effective visual simulation requires a fully developed manual language system.