Video-based quantification of body movement indicates negative symptoms: a replication

Objective: In schizophrenia, abnormalities in nonverbal behaviors
have always been considered as highly relevant. However, due to
methodological limitations, nonverbal behavior was rarely quantified
objectively. Recent methodological advances now allow a quantification
of body movement from ordinary video recordings. We
showed that patients’ objectively measured amount of movement in
social role-play interactions was closely associated with their symptom
profiles (Kupper, Ramseyer, Hoffmann, & Tschacher,
Schizophrenia Research 2010). In the present study, a replication of
these results in the context of semi-standardized PANSS (Positive and
Negative Syndrome Scale) interviews was intended.
Methods: 17 patients with schizophrenia were analyzed during the
initial 15-min sequence of a videotaped PANSS interview using
Motion Energy Analysis (MEA). The amount of patients’ movement
was then correlated with their PANSS symptom scores.
Results: Sizeable and significant correlations between negative symptoms
and reduced movements (r = -.68, p<0.01) and reduced
movement speed (r = -.80, p<0.001) were found. Moreover, cognitive
symptoms were related to reduced movement speed (r = -.70, p<.01).
Conclusion: Negative symptoms were reliably indicated by patients’
nonverbal behavior in psychopathology interviews. Hence, the main
result of our earlier study, examining patients’ nonverbal behavior in
role play tests, was replicated for the less structured interactions in
psychopathological interviews. Results could encourage the use of
MEA in a wide range of videotaped social interactions of patients
with schizophrenia and other psychiatric disorders.