Nonverbal Communication Processing in Deaf Adults: An Activation Likelihood Estimation Meta-Analysis

Background/Objectives: Hearing loss affects spoken language processing and leads to cortical reorganization in sensory systems. While neuroimaging research has explored cross-modal plasticity in visual language processing, there is a need to identify brain activation patterns consistently activated across different nonverbal communication tasks in deaf individuals. We hypothesized that deaf adults would show convergent activation across studies in visual and auditory cortices during nonverbal communication processing compared to typical hearing adults. Methods: To test this, we conducted an Activation Likelihood Estimation analysis of 14 neuroimaging studies using different visual linguistic stimuli and tasks in adults with prelingual deafness and age-matched hearing controls. Results: Contrary to expectations, deaf individuals did not show intramodal activation in the visual cortex. Instead, they demonstrated convergence activation in the left superior temporal gyrus only, indicating cross-modal recruitment of auditory regions, which supports visual-spatial language processing. Conclusions: These findings highlight the need for future research to clarify how cortical reorganization impacts speech perception outcomes following auditory restoration using neuroprostheses like cochlear implants.