Chronic Tinnitus and the Amygdala — or — When Your Ears Ring: Should You Answer?

"People with Tinnitus May Process Emotions Differently" Agata Blaszczak-Boxe, LiveScience (July 2, 2014)

"People with persistent ringing in their ears — a condition called tinnitus — may process emotions in the brain differently from people who do not have the condition, according to a new study.

"Using fMRI scans, researchers looked at people's brain activity while the patients listened to pleasant, unpleasant and neutral sounds. The study included people with tinnitus, people who had hearing loss but not tinnitus and people with normal hearing.

"The investigators found that when they played the pleasant and the unpleasant sounds, the amygdala, a brain region associated with processing emotions, had less activity in the tinnitus and hearing-loss patients than in people with normal hearing. When researchers played the pleasant sounds, tinnitus patients had more activity than people without tinnitus in two other brain regions associated with emotion, the parahippocampus and the insula.

" 'The amygdala isn't the only player,' when it comes to processing emotional sounds in people with tinnitus, study researcher Fatima Husain, a professor at University of Illinois at Urbana-Champaign, told Live Science...."

These researchers apparently haven't found that folks with chronic tinnitus experience different emotions: just that their amygdala shares the workload with the parahippocampus and the insula.

More than You Need to Know About Bits of the Brain

Apparently the parahippocampus is also called the parahippocampal gyrus, the parahippocampal cortex is what medicos call the posterior parahippocampal gyrus and the middle part of the fusiform gyrus. "Hippocampus" is also what you'd call a mythical critter with the front half of a horse and the back half of a dolphin, and the Lemming's mind is wandering.

The posterior parahippocampal gyrus and fusiform gyrus usually process visual information: colors; recognition of faces, bodies, and written words; that sort of thing. The parahippocampal gyrus on the right side may also identify sarcasm: then again, maybe not.

The amygdala is right next to the parahippocampus, which may help explain why overflow from the amygdala gets shunted to the parahippocampus. In complex vertebrates, humans included, the amygdala forms and stores memories associated with emotional events. It also processes memories on their way to long-term/permanent memory.

That's a busy little bit of brain. Small wonder that humans with constantly ringing ears have some of the 'how do I feel about this sound' work farmed out to other processing centers. Otherwise they might have trouble remembering stuff like why they went to the grocery, or when the wife's birthday is.

Not that husbands are renowned for remembering birthdays, anniversaries, or grocery lists: which is a little odd, since adult male humans and rats have bigger amygdalas than their female counterparts; or is that amygdali; which reminds the Lemming of Salvador Dali, which is another topic.



(From Salvador Dalí; via Salvador Dalí Museum, St. Petersburg, Florida and Wikipedia; used w/o permission.)
(The Chromosome of a Highly-coloured Fish's Eye Starting the Harmonious Disintegration of the Persistence of Memory.)

Vaguely-related posts:

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• "QWERTY, Keyboards, Fluency, and Feelings"
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• "Tuning in on the Brain's 'Voice' "
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• "No Fear: That Could Be a Problem"
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• "Infrasound: Be Afraid, be Very Afraid"
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  "Or, get informed...."