“Unique” brain area seen only in humans

“Unique” brain area seen only in humans

In this schematic, the later­al front­al pole pre­front­al cor­tex is shown as the dark red area at the right.

Ox­ford Uni­vers­ity re­search­ers have iden­ti­fied a small zone at the very front of the hu­man brain that looks un­like an­y­thing in the brains of some of our clos­est mon­key rel­a­tives.

The brain ar­ea is con­sid­ered to be in­ti­mately in­volved in some of the most ad­vanced plan­ning and de­ci­sion-mak­ing pro­cesses that we think of as be­ing es­pe­cially hu­man.

“We tend to think that be­ing able to plan in­to the fu­ture, be flex­i­ble in our ap­proach and learn from oth­ers are things that are par­tic­u­larly im­pres­sive about hu­mans. We’ve iden­ti­fied an ar­ea of the brain that ap­pears to be un­iquely hu­man and is likely to have some­thing to do with these cog­ni­tive pow­ers,” said in­ves­ti­ga­tor Mat­thew Rush­worth of Ox­ford Uni­vers­ity.

The sci­en­tists scanned the brains of 25 adult vol­un­teers us­ing Mag­net­ic Res­o­nance Im­ag­ing to iden­ti­fy key com­po­nents of a brain re­gion called the ven­tro­lat­eral front­al cor­tex. The re­sults were then com­pared to equiv­a­lent da­ta from 25 ma­caque mon­keys.

The ven­tro­lat­eral front­al cor­tex is in­volved in many of the high­est as­pects of cog­ni­tion and lan­guage, and is only found in hu­mans and their close rel­a­tives such as apes and mon­keys, said the in­vest­iga­tors, who re­ported their find­ings in the re­search jour­nal Neu­ron.

“The brain is a mo­sa­ic of in­ter­linked ar­e­as. We wanted to look at this very im­por­tant re­gion of the front­al part of the brain and see how many tiles there are and where they are placed,” said Rush­worth.

“We al­so looked at the con­nec­tions of each tile – how they are wired up to the rest of the brain – as it is these con­nec­tions that de­ter­mine the in­forma­t­ion that can reach that com­po­nent part and the in­flu­ence that part can have on oth­er brain re­gions.”

The re­search­ers di­vid­ed the hu­man ven­tro­lat­eral front­al cor­tex in­to 12 ar­e­as that were con­sist­ent across all peo­ple. “Each of these 12 ar­e­as has its own pat­tern of con­nec­tions with the rest of the brain, a sort of ‘neu­ral fin­ger­print,’ tell­ing us it is do­ing some­thing un­ique,” said Rush­worth.

Mon­keys shared si­m­i­lar struc­ture in 11 of the 12 ar­e­as, with si­m­i­lar con­nec­tions to oth­er brain ar­e­as, the sci­en­tists found. But one ar­ea of the hu­man ven­tro­lat­eral front­al cor­tex had no equiv­a­lent in the ma­caque—an ar­ea called the lat­er­al front­al pole prefront­al cor­tex.

This “does not seem to have an equiv­a­lent in the mon­key at al­l,” said co-author Franz-Xaver Neu­bert of Ox­ford Uni­vers­ity. “This ar­ea has been iden­ti­fied with stra­te­gic plan­ning and de­ci­sion mak­ing as well as “mul­ti­-tasking.’“

The re­search group al­so found that the au­di­to­ry parts of the brain were very well con­nect­ed with the hu­man prefront­al cor­tex, but much less so in the ma­caque. The re­search­ers sug­gest this may be crit­i­cal for our abil­ity to un­der­stand and speak.

Comments

Related Posts