Featured Research

from universities, journals, and other organizations

Groundbreaking model explains how the brain learns to ignore familiar stimuli

Date:
June 18, 2014
Source:
Trinity College Dublin
Summary:
A neuroscientist has proposed a new, ground-breaking explanation for the process of 'habituation,' which allows the brain to filter out significant environmental stimuli from the insignificant, and which is altered in Austim Spectrum Disorders.

A neuroscientist from Trinity College Dublin has proposed a new, ground-breaking explanation for the fundamental process of 'habituation', which has never been completely understood by neuroscientists.

Related Articles


Typically, our response to a stimulus is reduced over time if we are repeatedly exposed to it. This process of habituation enables organisms to identify and selectively ignore irrelevant, familiar objects and events that they encounter again and again. Habituation therefore allows the brain to selectively engage with new stimuli, or those that it 'knows' to be relevant. For example, the unusual sensation created by a spider walking over our skin should elicit an appropriate evasive response, but the touch of a shirt or blouse on the same skin should be functionally ignored by the nervous system. If habituation does not occur, then such unimportant stimuli become distracting, which means that complex environments can become overwhelming.

The new perspective on the way habituation occurs has implications for our understanding of neuropsychiatric conditions, because normal habituation, emotional responses and attentional abilities are altered in several of these conditions. In particular, hypersensitivity to complex environments is common in individuals on the autism spectrum.

Habituation has long been recognised as the most fundamental form of learning, but it has never been satisfactorily explained. In a Perspective article just published in the leading international journal Neuron, Professor of Neurogenetics in the School of Genetics & Microbiology at Trinity, Mani Ramaswami, explains habituation through what he terms the 'negative-image model.' The model proposes and explains how a repeated activation of any group of neurons that respond to a given stimulus results in the build-up of 'negative activation', which inhibits responses from this same group of cells.

For example, the first view of an unfamiliar and scary face can trigger a fearful response. However after multiple exposures, the group of neurons activated by the face is less effective at activating fear centres because of increased inhibition on this same group of neurons. Significantly, a strong response to new faces persists for much longer in people on the autism spectrum. This matched increase in inhibition (the 'negative image'), proposed to underlie habituation, is not normally consciously perceived but it can be revealed under particular conditions.

Professor Ramaswami said: "This Perspective outlines scalable circuit mechanisms that can account for habituation to stimuli encoded by very small or very large assemblies of neurons. Its strength is its simplicity, its basis in experimental data, and its ability to explain many features of habituation. However, more high-quality studies of habituation mechanisms will be required to establish its generality."

Professor of Experimental Brain Research at Trinity, and Director of the Trinity College Institute for Neuroscience, Shane O'Mara, said: "The arguments and ideas expressed by Professor Ramaswami should lead to additions and changes to our current text-book sections on habituation, which is a process of great relevance to cognition, attention and psychiatric disease. It is possible that highlighting the process of negative image formation as crucial for habituation will prove useful to clinical genetic studies of autism, by helping to place diverse autism susceptibility genes in a common biological pathway."


Story Source:

The above story is based on materials provided by Trinity College Dublin. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mani Ramaswami. Network Plasticity in Adaptive Filtering and Behavioral Habituation. Neuron, 2014; 82 (6): 1216 DOI: 10.1016/j.neuron.2014.04.035

Cite This Page:

Trinity College Dublin. "Groundbreaking model explains how the brain learns to ignore familiar stimuli." ScienceDaily. ScienceDaily, 18 June 2014. <www.sciencedaily.com/releases/2014/06/140618131957.htm>.
Trinity College Dublin. (2014, June 18). Groundbreaking model explains how the brain learns to ignore familiar stimuli. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2014/06/140618131957.htm
Trinity College Dublin. "Groundbreaking model explains how the brain learns to ignore familiar stimuli." ScienceDaily. www.sciencedaily.com/releases/2014/06/140618131957.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Former NFL Players Donate Brains to Science

Former NFL Players Donate Brains to Science

Reuters - US Online Video (Mar. 3, 2015) — Super Bowl champions Sidney Rice and Steve Weatherford donate their brains, post-mortem, to scientific research into repetitive brain trauma. Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Alzheimer's Protein Plaque Found In 20-Year-Olds

Alzheimer's Protein Plaque Found In 20-Year-Olds

Newsy (Mar. 3, 2015) — Researchers found an abnormal protein associated with Alzheimer&apos;s disease in the brains of 20-year-olds. Video provided by Newsy
Powered by NewsLook.com
This Nasal Treatment Could Help Ease Migraine Pain

This Nasal Treatment Could Help Ease Migraine Pain

Newsy (Mar. 2, 2015) — Researchers gave lidocaine to 112 patients, and about 88 percent of the subjects said they needed less migraine-relief medicine the next day. Video provided by Newsy
Powered by NewsLook.com
How Facebook Use Can Lead To Depression

How Facebook Use Can Lead To Depression

Newsy (Mar. 1, 2015) — Margaret Duffy of the University of Missouri talks about her study on the social network and the envy and depression that Facebook use can cause. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins