An accurate and rapidly calibrating speech neuroprosthesis.

Brain-computer interfaces can enable rapid, intuitive communication for people with paralysis by transforming the cortical activity associated with attempted speech into text on a computer screen. Despite recent advances, communication with brain-computer interfaces has been restricted by extensive training data requirements and inaccurate word output. A man in his 40's with ALS with tetraparesis and severe dysarthria (ALSFRS-R = 23) was enrolled into the BrainGate2 clinical trial. He underwent surgical implantation of four microelectrode arrays into his left precentral gyrus, which recorded neural activity from 256 intracortical electrodes. We report a speech neuroprosthesis that decoded his neural activity as he attempted to speak in both prompted and unstructured conversational settings. Decoded words were displayed on a screen, then vocalized using text-to-speech software designed to sound like his pre-ALS voice. On the first day of system use, following 30 minutes of attempted speech training data, the neuroprosthesis achieved 99.6% accuracy with a 50-word vocabulary. On the second day, the size of the possible output vocabulary increased to 125,000 words, and, after 1.4 additional hours of training data, the neuroprosthesis achieved 90.2% accuracy. With further training data, the neuroprosthesis sustained 97.5% accuracy beyond eight months after surgical implantation. The participant has used the neuroprosthesis to communicate in self-paced conversations for over 248 hours. In an individual with ALS and severe dysarthria, an intracortical speech neuroprosthesis reached a level of performance suitable to restore naturalistic communication after a brief training period.

The Development of Shyness from Late Childhood to Adolescence: A Longitudinal Study of Mexican-origin Youth.

Shyness, the tendency to be inhibited and uncomfortable in novel social situations, is a consequential personality trait, especially during adolescence. The present study examined the development of shyness from late childhood (age 10) through adolescence (age 16) using data from a large, longitudinal study of Mexican-origin youth (N = 674). Using both self- and mother-reports of shyness assessed via the Early Adolescent Temperament Questionnaire-Revised, we found moderate to high rank-order stabilities across two-year intervals and a mean-level decrease in shyness from age 10 to 16. Anxiety and depression were associated with higher initial levels of shyness, and anxiety was associated with greater decreases in shyness from age 10 to 16. Contrary to predictions, neither nativity (country of birth) nor language proficiency (English, Spanish) was associated with the development of shyness across adolescence. Thus, youth generally decline in shyness during adolescence, although there is substantial individual variability in shyness trajectories.