Patterns of brain ac­ti­vity pre­dict peo­ple’s de­ci­sions up to 10 sec­onds be­fore the peo­ple are aware of them, ac­cord­ing to new re­search that casts fresh doubt on whether we have free will.

The ancient debate over free will cen­ters on whether it’s an il­lu­sion to be­lieve our thoughts and de­ci­sions are in­de­pend­ent, since our brains really con­sist of atoms bouncing around ac­cord­ing to their own rules. The new study suggests the questioning many be justified.

April 15, 2008
Courtesy Nature Journals
and World Science staff

 

Infographic Illustrating Free Will Experiment

Re­search­ers tracked brain ac­ti­vity while peo­ple viewed a stream of let­ters on screen, and then pressed a but­ton. Each par­ti­ci­pant was asked to de­cide freely which of two but­tons to press and when to press it.Scan­ning the brains with a tech­nique called func­tion­al mag­net­ic res­o­nance im­ag­ing, the in­ves­ti­ga­tors used a sta­tis­ti­cal meth­od known as pat­tern rec­og­ni­tion to ex­am­ine brain ac­ti­vity as­so­ci­at­ed with each choice. Ac­ti­vity in two brain re­gions, called the pre­fron­tal and pa­ri­e­tal cor­tex, pre­dicted which but­ton the per­son would press, they found. These ar­eas have pre­vi­ously been linked to self-re­flec­tion, se­lec­tion amongst choices and ex­ec­u­tive con­trol.This ac­ti­vity oc­curred up to 10 sec­onds be­fore sub­jects were con­sciously aware of hav­ing made a de­ci­sion, ac­cord­ing to the re­search­ers. The find­ings, they added, sug­gest high-lev­el con­trol ar­eas start to pre­pare an up­com­ing de­ci­sion long be­fore it en­ters con­scious awareness. The stu­dy, by John-Dylan Haynes of the Max Planck In­sti­tute for Hu­man Cog­ni­tive and Brain Sci­ences in Leip­zig, Ger­ma­ny and col­leagues, is pub­lished on­line this week in the re­search jour­nal Na­ture Neu­ro­sci­ence.http://youtu.be/VQxJi0COTBo