Overview

• In essential tremor, unexpected offers elicited a reciprocal pattern with dopamine rising as serotonin fell, a dynamic that was absent in Parkinson’s disease.
• Researchers tied neurochemical responses to prediction errors during a social decision-making task performed intraoperatively in the caudate.
• Recordings were made in 2017–2018 with carbon-fiber electrodes during deep brain stimulation surgeries, capturing sub-second transmitter fluctuations.
• Reanalysis with reinforcement-learning and ideal-observer models, coupled with machine-learning–enhanced electrochemistry, exposed patterns not evident in earlier work.
• The team says the signature could aid future diagnostic or stratification efforts, while stressing that the findings are preliminary and require replication and larger cohorts.