Why does phonetic adaptation become less complete in adult learners of signed languages, compared to child learners?

💡 Explanation

Neural plasticity reduces sharply after puberty, because phonetic adaptation relies on forming new neural pathways to perceive and produce unfamiliar handshapes, locations, and movements. Therefore, plasticity reduction limits phonetic adaptation, rather than vocabulary, vision, or joint flexibility playing dominant roles.

• Why does a cochlear implant user struggle more to discriminate 'ba' from 'da' than 'ma' from 'na'?
• Why does the 'bank' in 'blood bank' avoid social taboo, unlike, say, 'blood money'?
• Why does 'Can you pass the salt?' function as a request rather than a query?
• If a sign language user attempts to describe a complex, multi-stage manufacturing process using only spatial grammar within a video call characterized by significant latency, which consequence follows?
• Why does inconsistent accent placement within machine-generated speech risk a decline in perceived user satisfaction from a voice assistant?
• Why does reaction time differ when Navajo and English speakers process spatial relations?