Affective prosody in frontotemporal dementia

“It's not what you said; it's how you said it!” How many times have you said or heard that while interacting with a family member or colleague? It is clear that tone of voice (modulations in pitch, loudness, and rhythm of speech, together called prosody) conveys a great deal of intent and emotion in nearly every exchange. Imagine that your spouse's response to a very special birthday gift is “I've never seen anything like it,” spoken in a completely monotone voice. You would not be able to tell if he or she loves it or hates it. On the flip side, suppose you say to your spouse, lovingly, “I can hardly believe we have been married for 20 years.” But she thinks you sound angry when you say that, so she retorts that she is happy to divorce you to put you out of your misery. As reported by Nevler et al.¹ in this issue of Neurology®, people with the behavioral variant of frontotemporal dementia (bvFTD) often have severe impairments in expression of emotion through affective prosody. They also often have trouble understanding affective prosody in others.² These deficits can lead to frequent misinterpretation and failures of communication. Deficits in prosody expression and comprehension are not specific to bvFTD. Survivors of right middle cerebral artery stroke^3,4 and people with autism,⁵ schizophrenia,⁶ and Parkinson disease⁷ also can have marked impairment in affective prosody recognition or production.