Emotional prosody expression in acoustic analysis in patients with right hemisphere ischemic stroke

The role of the right cerebral hemisphere in nonverbal speech activities remains controversial. Most research supports the dominant role of the right hemisphere in the control of emotional prosody. There has been significant discussion of the participation of cortical and subcortical structures of the right hemisphere in the processing of various acoustic speech parameters. The aim of this study was an acoustic analysis of the speech parameters during emotional expression in right hemisphere ischemic strokes with an attempt to reference the results to lesion location.

Acoustic speech analysis was conducted on forty-six right-handed patients with right-middle cerebral artery stroke, together with 34 age-matched people in the control group. We compared the results of acoustic studies between patients with varying infarct locations and the control group.

Variations in fundamental frequency during verbal expression of joy, anger and sadness were significantly smaller in the patient group than in the control group. Cortical lesion caused more restrictions in fundamental frequency variation in the expression of joy and a lower voice intensity in expressions of anger and joy compared to those patients with subcortical lesions.

Cortical lesion was associated with a more impaired expression of emotional prosody than subcortical lesion. The results indicate the leading role of the cortical structures of the right hemisphere in the expression of emotional prosody.