To investigate the feasibility of quantitative measurement of auditory startle using time-aligned electromyography(EMG) recordings collected during the presentation of auditory stimuli, which vary in frequency.

The auditory startle response is an important component of neurological assessment in patients with Disorders of Consciousness (DOC). However, it can be challenging to assess because it requires a clinician to subjectively assess behavioral responses, which can be subtle. We investigate a quantitative approach to measuring auditory startle in DOC patients using EMG during the presentation of auditory stimuli("oddball task") that vary in frequency, which is an established method to activate the sympathetic arousal system.

We recruited six patients who were hospitalized with DOC due to various etiologies. We obtained EMG from the arm as patients were presented with auditory stimuli, which varied in frequency. Specifically, we presented two distinct tones (A, or Ab) in a randomly interleaved manner. One tone was assigned to be the “oddball” tone and occurred much less frequently than the other “standard” tone (80% vs. 20% probability of occurrence for the standard vs. rare/oddball, respectively). After 100 trials, the tones were presented again with a "contingency reversal," such that the rare tone on the first 100 trials was now the common tone, and vice versa.