1. Linguistic and psycholinguistic tests are more useful than motion capture technology in distinguishing between sign and gesture.
2. Motion capture technology provides less information about linguistic constraints and categories, and better models are needed to account for differences between co-speech and co-sign gesture.
3. Linguistic analyses and psycholinguistic experiments can provide clearer hypotheses about how gradience is expressed in both the vocal and manual modalities, and better models of the relation between language and gesture can help determine how sign and gesture are combined.
The article argues that linguistic and psycholinguistic tests are more useful than motion capture technology in distinguishing between sign and gesture. The author critiques Goldin-Meadow and Brentari's call for new technology to analyze motion and location, arguing that the analogy between motion capture technology and the spectrograph is flawed because only vocal articulators are hidden. The author suggests that better models are needed to account for differences between co-speech and co-sign gesture, such as different degrees of optionality and the existence of beat gestures.
The article provides a thoughtful critique of Goldin-Meadow and Brentari's approach, highlighting potential flaws in their reasoning. However, the article could benefit from more evidence to support its claims. For example, while the author suggests that reduced variability in signers' movements could be due to motor expertise rather than linguistic differences, they do not provide any empirical evidence to support this claim.
Additionally, the article could benefit from exploring counterarguments more thoroughly. While the author notes that beat gestures are ubiquitous for speakers but it is unclear whether the parallel exists for signers, they do not explore why this might be the case or what implications it might have for their argument.
Overall, while the article provides a valuable critique of Goldin-Meadow and Brentari's approach, it would benefit from more evidence to support its claims and a more thorough exploration of counterarguments.