Enrique R. Pouget

Reflections of depression in acoustic measures of the patient’s speech

BACKGROUND The literature on acoustic measures of voice in depression is reviewed. Authors have separated results derived from studies of automatic speech, such as counting or reading, from free speech. Free speech requires cognitive activity such as word finding and discourse planning in addition to the motor activity of automatic speech. Also, results have been less ambiguous if homogeneous groups of agitated or retarded depressed patients were examined. METHODS These distinctions are applied to the results of a 12-week double-blind treatment trial that compared response to nortriptyline (25-100 mg/day) with sertraline (50-150 mg/day). Twelve male and ten female elderly depressed patients and an age-matched normal control group (n=19) were studied. Patients were divided into retarded or agitated groups on the basis of ratings. Results from measures of fluency (speech productivity and pausing) and prosody (emphasis and inflection) are described. RESULTS Depressed patients showed less prosody than the normal subjects. Improvement in the retarded group was reflected in briefer pauses but not longer utterances. There was a trend in the agitated group for improvement to be reflected in the utterance but not the pause measure. CONCLUSIONS Clinical impressions are substantially related to acoustic parameters. Temporal changes associated with depression appear to reflect the depressed state whereas prosodic features seem to reflect a depressed trait. Acoustic measures of the patients speech may provide objective procedures to aid in the evaluation of depression. Limitations of the study are discussed.

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 patients 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.

Acoustic distinctions in the speech of male psychopaths.

A key feature of psychopathy is the ability to deceive, manipulate, and con the unwary, while seeming to be perfectly sincere. Is this impression of sincerity achieved solely through body gestures and facial expression, or is there also something different about the voice quality of psychopaths? We analyzed the acoustic characteristics of speech in 20 male offenders (10 psychopaths and 10 nonpsychopaths), assessed with the Psychopathy Checklist—Revised (Hare, 1991). We used a computer program developed by Alpert, Merewether, Homel, Martz, and Lomask (1986) to measure variations in amplitude and prosody. Results indicated that psychopaths spoke more quietly than controls and did not differentiate, in voice emphasis, between neutral and affective words. These findings are consistent with the developing view that psychopaths are insensitive to the emotional connotations of language. In addition, their vocal characteristics may be part of a self-presentation mode designed to manipulate and control interpersonal interactions.

The syntactic role of pauses in the speech of schizophrenic patients with alogia.

This study examines the relation between alogia and pausing. The authors analyzed the flow of speech of 17 male schizophrenic patients during an interview, particularly the pauses that occurred within and between syntactic clauses and those that occurred as the turn switched from the interviewers question to the patients response. The strongest predictor of alogia ratings was the duration of switching pauses; the frequency of long within-clause pauses was also significantly related to alogia, but the frequency of between-clause pauses showed a trend toward a negative relation with alogia. Words following within-clause pauses were more likely to be content words than function words, and the content words were less frequent in the English language than the speakers other words. This suggests that alogic patients have difficulty in word finding and in thought formulation, as well as a general increase in the duration of all pauses.