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 (Nature Neuroscience)

Infographic Source: http://www.nature.com/neuro/index.html

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.