When the human ear encounters music, a number of brain systems are engaged by the incoming sound. The music signal is first directed to the thalamus, which relays the information to the primary auditory cortex. Once activated, this part of the brain is thought to identify the fundamental elements of the music, such as pitch and loudness. The secondary auditory cortex then processes the harmony, melody and rhythmic patterns, and the tertiary auditory cortex seems to integrate everything into the overall experience of music. Such is the process to the best of modern science's understanding, but the complex mental digestion of music is not yet fully understood.
Equally difficult to explain is a strange phenomenon known as "musical hallucinations" which is a condition very similar to having a song stuck in one's head; but the music is considerably more true-to-life, it is heard almost non-stop, and it is practically impossible to ignore.
The condition was first identified over a century ago, though phantom songs were haunting people since long before it was officially recognized by medicine. Sufferers describe it as a constant flow of random songs, with one song often leading to the next in a never-ending shuffle-mode torment. In some cases, a single song is heard repeatedly. The sound is so vivid that when a person first starts experiencing the symptoms, they often ask others whether they can hear the music, too. Many of the people who complain of the affliction are elderly, and often they are deaf or hard-of-hearing.
Historically, little effort has been made to study the strange phenomenon, but Doctors Victor Aziz and Nick Warner of Wales recently conducted an analysis of thirty cases of musical hallucinations. The study, which spanned fifteen years' worth of patients, has revealed some interesting new information about the condition.
The condition differs from schizophrenia in that there are no imaginary voices speaking to the sufferer, just a constant stream of music. Women reported the problem more often than men, and the average age of the patients was seventy-eight. The type of music heard by these individuals varied greatly, but about two-thirds of those studied tended to hear religious music. Dr. Aziz suggests that the songs the brain regurgitates may be those which the patient has heard a lot during his or her life, and/or those songs with special emotional significance.
Over the years, a handful of PET scans have been done on people who experience these hallucinations. The results of those tests indicate that most of the brain regions which are stimulated by music in a normal person are highly active during these hallucinations. The notable exception is the primary auditory cortex-- the area responsible for early music processing-- which shows very little activity. It is possible that musical hallucinations are the product of a mental malfunction where random impulses generated by the brain itself are detected by the secondary and tertiary auditory cortices, and interpreted as music. This could also explain why so many of the sufferers happen to be deaf or hearing-impaired; it is likely that the stimuli-deprived hearing centers of the brain become hypersensitive to these impulses.
An additional study by Haggai Hermesh, M.D., a senior lecturer in psychiatry at Tel Aviv University in Israel, showed that many people who experience musical hallucinations also suffer from obsessive-compulsive disorder (OCD). His team of researchers examined people with a myriad of mental disorders, including bipolar disorder, major depressive disorder, obsessive-compulsive disorder, panic disorder, schizophrenia, schizoaffective disorder, and social phobia. Of those groups, none ranked nearly as high in instances of musical hallucinations as those patients with OCD, a curiously high 41%.
Unfortunately, the information gathered by these studies has done little to produce useful treatment. Some psychiatrists have tried prescribing antipsychotic drugs to relieve the musical hallucinations, but most such attempts have met with failure. The affliction's relationship with OCD suggests that anti-OCD drugs may offer some relief, but that theory is still a long way from clinical testing. At present, the only effective treatment for sufferers is to listen to real music, which essentially gives the music-processing areas of the brain something to chew on... but of course that solution is of little help to the hard-of-hearing.
For those sufferers without any escape from the non-stop jukebox in their minds, one can only hope that the next song is a good one.