Tinnitus, experienced by about 20% of people, has long been a complaint without any overt signs to measure. Recent bran imaging techniques showed that tinnitus was related to increased neural firing and changes in connectivity in certain brain regions.
Using functional near-infrared spectroscopy (fNIRS), researchers in 2014 were able to map anomalous activity in the right auditory cortex of tinnitus sufferers, and in 2018, researchers showed that signals there were related to both the presence and intensity of the tinnitus.
fNIRS measures the absorption of near-infrared light shining into the head to measure oxy- and deoxyhaemoglobin levels, which are associated with cerebral activity.
Using machine learning which compared 25 patients with tinnitus to 21 healthy patients, the researchers were able to isolate two distinct areas of
The algorithms were able to diagnose tinnitus with 78% accuracy and gauge intensity with 87% accuracy.
The imaging showed higher connectivity in the temporal-frontal lobe, linked to tinnitus duration and stress, and higher connectivity in the temporal-occipital lobe, which is linked to sound intensity. It opens the possibility of measuring both loudness and annoyance with fNIRS, and also supports preliminary research showing that by making the brain process other information, the tinnitus intensity can be reduced.
Source: Science Alert
