Earth Science News  





. Will Our Future Brains Be Smaller

Extra brain means extra weight and energy required to carry it around.
by Staff Writers
Bristol, UK (SPX) Jul 10, 2008
The speed at which we react to threatening situations can have life or death implications. In the more primitive past, it could have meant escaping a wild animal; today it might mean swerving to avoid a head-on car crash.

It has been thought for some years that mammals have two decision-making systems in their brains which operate at different speeds to cope with different situations.

New research from the University of Bristol supports this theory and has shown that the evolutionary pressures arising from the older, faster, but less accurate, part of the brain may have shaped the more recent development of the slower-acting but more precise cortex, found in humans and higher animals.

The research has been published in Proceedings of the Royal Society B.

Pete Trimmer, lead author on the study, explained: "If we compare the brain of a human with that of a reptile, we find they are very similar except that mammals have a large 'outer cortex' around the outside of the existing 'sub-cortical' brain, that is common to other vertebrates.

"The fact that lizards make decisions indicates that the sub-cortical brain in humans is also likely to be used in decision-making. However, fMRI scans now reveal that parts of the outer cortex (which developed more recently in our evolutionary past) are also used when making decisions."

Why does the brain need these two decision-making areas? What benefit does the new cortex bring? After all, extra brain means extra weight and energy required to carry it around. Furthermore, is the older sub-cortical system now largely redundant? If so, could we expect it to atrophy in future humans so our brains become smaller?

To address these questions, Trimmer built theoretical models representing the two systems in which the sub-cortical system was assumed to act very quickly but inaccurately, whereas the cortex allowed information to be gathered before making an informed decision, and was therefore slower.

The results of their modelling showed that when the threat level is high, such as the risk of being attacked by a dangerous animal, it is very useful to have the fast-acting, if inaccurate, system.

But when dealing with situations which don't occur very often, or complex scenarios with many conflicting cues such as social situations, the cortical system is of more use than the sub-cortical system.

Trimmer commented: "As life became more complex, the benefit of gathering information before making a decision put an evolutionary pressure on the early brain. This may have led to the rapid development of the cortex in mammals. So if humans continue to live in a world of dangers such as wild animals or fast-moving cars, there will still be an evolutionary benefit to maintaining the sub-cortical system, and it is unlikely to atrophy in future humans."

Community
Email This Article
Comment On This Article

Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
University of Bristol
All About Human Beings and How We Got To Be Here




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
A Microsatellite-Guided Insight Into The Genetic Status Of The Adi Tribe
Washington DC (SPX) Jul 07, 2008
North-east India has always been a hotspot for population geneticists due to its unique, strategic geographic location and the presence of linguistically, culturally and demographically diverse populations practicing varied occupations (from hunter-gathering to settled agriculture).

.
Get Our Free Newsletters Via Email
  



  • Disaster deaths worse so far in 2008 than tsunami year: Munich Re
  • Immune Buildings Designed To Combat Chemical Warfare And Diseases
  • Extended Cyclone Relief Efforts Aided From Space
  • Australia, Japan, US plan disaster relief exercises

  • World ports tackle greenhouse gas emissions
  • 'Serious omission' in G8 summit climate pledge: IPCC chief
  • G8 leaders agree on halving emissions by 2050
  • Analysis: Climate study criticizes G8

  • India And France Joint Working Group Meet To Discuss Space
  • Raytheon Submits Proposal For NOAA Environmental Satellite Ground Segment
  • NASA Mission To Be Crystal Ball Into Future Of Oceans And Past Seas
  • ESA Satellite Assesses Damage Of Norway's Largest Fire

  • Analysis: Mongolian energy prices
  • Analysis: Peru's oil draws Indian interest
  • Oil prices calm as markets mull Iran missile test
  • AES Expands Its Wind Platform In China

  • Pandemic Mutations In Bird Flu Revealed
  • Researchers Identify Potential Drug Candidates To Combat Bird Flu
  • Anti-retroviral drug cocktails slash AIDS deaths: study
  • China seals off quake town over epidemic fears: report

  • Species Diversity Less Dramatic Than Believed
  • Instances Of Mass Die-Offs In Wild Lions Precipitated By Extreme Climate Change
  • Tigers Disappear From Himalayan Refuge
  • Human Influences Challenge Penguin Populations

  • Improving Swine Waste Fertilizer
  • Pesticides Persist In Ground Water
  • Only fraction of people recycle old mobile phones: study
  • Italy's Berlusconi vows to clean up Naples by mid-July

  • Will Our Future Brains Be Smaller
  • Do We Think That Machines Can Think
  • A Microsatellite-Guided Insight Into The Genetic Status Of The Adi Tribe
  • New Map IDs The Core Of The Human Brain

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement