The initiation of a hand grip is delayed by silently reading an incompatible syllable

Abstract The movements of phonation structures (e.g., tongue) are said to facilitate compatible hand movements. For example, onset latencies of precision and power hand grips (Reaction Time: RT) are shortened with the production of syllables that share similar sensory consequences (e.g., tactile sensation occurring at the tip of both effectors). However, it is not known if such syllable-grip effects are due to action compatibility vs. interference, and if such facilitation/ interference is due to covertly or overtly reading the syllable. To answer the associated empirical questions, the present experiment involved participants initiating a precision or power grip without the covert/ overt reading of a syllable, or while covertly or overtly reading the syllable /ti/ or /ka/. In both the covert and overt reading conditions, the syllable /ka/ interfered with precision grip RTs and the syllable /ti/ interfered with power grip RTs. In contrast, the syllable /ti/ or /ka/ did not interfere or facilitate power or precision grip RTs, respectively. These findings support the notion of syllable-grip interference but not compatibility and that such interference can be observed with silent reading alone.