Biomedical subjects

Michael Cannizzaro

Publications and source records attributed to Michael Cannizzaro.

3 recordsLinked to original sources

PubMed2004

Variability in fundamental frequency during speech in prodromal and incipient Parkinson's disease: a longitudinal case study.

Nearly two centuries ago, first observed that a particular pattern of speech changes occur in patients with idiopathic Parkinson's disease (PD). Numerous studies have documented these changes using a wide variety of acoustic measures, and yet few studies have attempted to quantify any such changes longitudinally, through the early course of the disease. Moreover, no attempt has been made to determine if speech changes are evident during the prodromal period, prior to the onset of clinically noticeable symptoms. This case-control pilot study is a first attempt to determine if changes in fundamental frequency variability during speech, an acoustic measure known to be affected later in the course of the disease, are evident during the prodromal period. A retrospective analysis of videotape footage recorded and made available by a leading national television news service. Videotape samples were obtained for a single individual (and a well-matched control subject) over an 11-year period of this individual's life (7 years prior to diagnosis of PD, and 3 years post-diagnosis). Results suggest that changes in F0 variability can be detected as early as 5 years prior to diagnosis (consistent with findings from other laboratories that have relied on cross-sectional study approaches). This pilot study supports the utility of such a design approach, and these results warrant continued effort to better understand the onset of PD and sensitivity of measurement of voice acoustical changes during the prodromal period.

Adult↗

PubMed2004

Voice acoustical measurement of the severity of major depression.

A number of empirical studies have documented the relationship between quantifiable and objective acoustical measures of voice and speech, and clinical subjective ratings of severity of Major Depression. To further explore this relationship, speech samples were extracted from videotape recordings of structured interviews made during the administration of the 17-item Hamilton Depression Rating Scale (HDRS; ). Pilot data were obtained from seven subjects (five males, two females) from videotapes that have been used to train expert raters on the administration and scoring of the HDRS. Several speech samples were isolated for each subject and processed to obtain the acoustic measurements. Acoustic measures were selected on the basis that they were correlated with HDRS ratings of symptom severity as seen under ideal voice recording conditions in previous studies. Our findings corroborate earlier reports that speaking rate is well correlated (negatively) with HDRS scores, with a strong correlation and nearly significant trend seen for the measure of pitch variability. A moderate pairwise correlation between percent pause time and HDRS score was also revealed, although this relationship was not statistically significant. The results from this cross-sectional study further demonstrate the ability of voice and speech signal analyses to objectively track severity of depression. In the present case, it is suggested that this relationship is robust enough to be found despite the less than ideal recording conditions and equipment used during the original videotape recording. Voice acoustical analyses may provide a powerful compliment to the standard clinical interview for depression. Use of such measures increases the range of techniques that are available to explore the neurobiological substrates of Major Depression, its treatment, and the dynamic interplay of the systems that govern the motor, cognitive, and emotional aspects of speech production.

Adult↗

PubMed2004

Speech content analysis in feigned depression.

The present study investigated the utility of employing computerized speech content analysis software to detect feigned depression in psychologically healthy adults. Twenty-two subjects between the ages of 19 and 54 years old, who scored lower than 10 on the Beck depression inventory (BDI. 1996), were asked to speak freely in response to a neutral stimulus. Participants performed this task in pseudo-randomized order for two experimental conditions: a control state and feigned depression. Computerized transcript analysis data were then subjected to paired t-tests to detect differences based on participants' lexical choices under the two conditions. Results indicated that one semantic category, tool, was significantly different between the feigned depression and control conditions. Another semantic category of interest, arousal, demonstrated a strong trend toward significance. Computerized lexical choice categories previously found to accurately identify persons with depression were not found to be significantly different in the discourse of our participants in the feigning condition. These results are discussed in terms of the use of computerized speech content analysis as a method for possibly identifying persons who may be intentionally feigning depression.

Adult↗