Hyper­ac­tive cen­tre makes us stut­ter

Science Illustrated - - SCIENCE UPDATE -

About 1 % of all adults stut­ter, and now, sci­en­tists are try­ing to find out why. Sev­eral stud­ies in­di­cate that stut­ter­ing is caused by in­ter­rup­tion of the co­op­er­a­tion be­tween two brain cen­tres lo­cated on ei­ther side of the frontal lobe. In the left cere­bral hemi­sphere, the cen­tre controls our speech mo­tions, whereas the same cen­tre in the right cere­bral hemi­sphere im­pedes speech.

Sci­en­tists from the Max Planck In­sti­tute in Ger­many have scanned the brains of stut­ter­ers, as they imag­ined that they were stat­ing the names of months. A con­trol group was asked to do the same thing. The re­sults showed hy­per­ac­tiv­ity in the right brain cen­tre of stut­ter­ers, im­ped­ing the ac­tiv­ity in the left one. In non-stut­ter­ers, the ac­tiv­ity was much more bal­anced.

The ex­pla­na­tion of stut­ter­ing is prob­a­bly to be found in the right cere­bral hemi­sphere. The scans also re­vealed that the stut­ter­ers had a par­tic­u­larly ac­tive bun­dle of nerve threads that orig­i­nates from the right brain cen­tre. The more a test sub­ject stut­tered, the higher the ac­tiv­ity of the nerve bun­dle. It is prob­a­bly those very nerve threads that carry im­pair­ing sig­nals from the right to the left cere­bral hemi­sphere, caus­ing stut­ter­ing.

Two brain cen­tres con­trol our speech. If their co­op­er­a­tion fails, we be­gin to stut­ter.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.