Laughter serves a fundamental social purpose, the appropriate use of which requires recognition of social norms. So what happens when these interpersonal abilities are affected, such as in the frontotemporal dementias? Does use of laughter change too? Dr Peter Pressman (Rocky Mountain Alzheimer’s Disease Center, University of Colorado, USA) talks to Elizabeth Highton about observing conversational laughter in frontotemporal dementia. This paper was chosen for this month’s Editor’s Choice and can be found here: http://jnnp.bmj.com/content/88/5/418.