If you've ever had a song stuck in your head, you'll be interested in the latest research investigating the brain region responsible for recognition of familiar tunes revealed as part of a study into Semantic dementia.
Semantic dementia research
Semantic dementia (SD) is a rare type of dementia characterised by a loss of semantic memory, memory for generalised concept based factual information (i.e, general knowledge). The most common symptoms, particularly early on, are an impaired ability to retrieve words from memory and impaired comprehension of word meanings. It also affects patients' ability to recognise objects and sounds.
Recent research has shown that SD patients also may have difficulty recognising familiar tunes. Professor John Hodges and his team at Neuroscience Research Australia found that compared to healthy controls and individuals with a different type of dementia, Alzheimer's dementia, people with SD had much more difficulty recognising well known songs, such as 'Happy Birthday' and 'Waltzing Matilda'. The other groups recognised the songs about 90% of the time, whereas those with SD recognised them less than 60% of the time.
People with SD show significant shrinkage (atrophy) in the temporal lobe region of the brain, which is responsible for semantic memory.
However, interestingly, there were 3 people with SD who performed well on the song recognition task. These individuals were further investigated and it was found that they showed less atrophy than the other SD patients in the region of the right temporal lobe. They were also bettter than the rest of the group at recognising famous faces.
The right temporal region may therefore be responsible for recognition of information such as familar tunes, faces and possibly objects. Or, as Dr Oliver Piguet, a member of the team, calls it, "a brain region involved in uniqueness".
The value of the research is that it has linked visual and auditory recognition, which are usually considered distinct functions and highlighted that there are key differences between various types of dementia, which can have implications for their treatment and management.