A comparison of clinical ratings with vocal acoustic measures of flat affect and alogia.

In this report we compare clinical ratings of flat affect and alogia with objective measures of the patient's speech prosody and productivity. Thirty schizophrenic patients were evaluated with the Scale for the Assessment of Negative Symptoms (SANS) and the St. Hans Rating Scale for extra pyramidal side effects. Their speech was recorded and analyzed acoustically for measures of prosody and productivity. Correlations between pairs of SANS items and acoustic measures (e.g. Vocal Inflection and Fundamental Frequency Variance) were weak. The SANS item and global ratings were strongly related. Ratings of bradykinesia overlapped with the SANS ratings but not with the acoustic measures. The SANS ratings appear to be derived from global impressions, with diffuse confounding of flat affect with alogia, and with bradykinesia. Acoustic analysis has the potential to provide objective measures that may help develop operational definitions of these constructs and enhance clinical assessment.