Background Listening to one speaker in the presence of others (the ‘cocktail party’ problem) increases demands on attention and cognitive control. This study investigated the function of fronto-parietal systems and auditory regions in patients with progressive memory impairment.

Methods Twenty-five healthy volunteers (controls) and 32 patients were studied with functional MRI. The task involved attending to a female speaker, either in the absence or the presence of a masking male speaker.

Results A behavioural measure designed to assess success at attending to the female speaker demonstrated a significant impairment in the patient group compared to the controls. This was associated with reduced activity in the dorsal anterior cingulate cortex (dACC), involved in attention and cognitive control, and in the left planum temporale (lPT), an auditory region central to solving the ‘cocktail party’ problem. However, treatment with galantamine in 18 patients resulted in no behavioural improvement and no increase in dACC or lPT activity.

Conclusions An inability to register verbal information when listening in the presence of distracting background speech will contribute to complaints of ‘impaired memory’ and social isolation. We did not find evidence that central cholinesterase inhibition can improve this function in patients complaining of progressive memory decline.