Navigation Links
Stuck in neutral: Brain defect traps schizophrenics in twilight zone
Date:8/16/2014

People with schizophrenia struggle to turn goals into actions because brain structures governing desire and emotion are less active and fail to pass goal-directed messages to cortical regions affecting human decision-making, new research reveals.

Published in Biological Psychiatry, the finding by a University of Sydney research team is the first to illustrate the inability to initiate goal-directed behaviour common in people with schizophrenia.

The finding may explain why people with schizophrenia have difficulty achieving real-world goals such as making friends, completing education and finding employment.

"The apparent lack of motivation in schizophrenic patients isn't because they lack goals or don't enjoy rewards and pleasure," says the University of Sydney's Dr Richard Morris, the study's lead author. "They enjoy as many experiences as other people, including food, movies and scenes of natural beauty.

"What appears to block them are specific brain deficits that prevent them from converting their desires and goals into choices and behaviour."

Using a control group research design, the researchers used a two-prong approach to reveal how and why schizophrenics fail to convert their preferences into congruent choices.

First, using a series of experiments involving choosing between different snack food rewards, experimenters revealed that:

  • schizophrenic subjects had a liking for snack foods equivalent to healthy adults
  • when researchers reduced the value of one of the snacks, both subjects and healthy adults subsequently preferred different snacks, as expected
  • surprisingly, schizophrenic subjects had major difficulty choosing their preferred snack when provided with a choice between their preferred snack and the devalued snack.

Second, researchers used functional magnetic resonance imaging (fMRI) to measures brain activity while study subjects performed learning tasks involving snack foods. This technique relies on the fact that cerebral blood flow and neuronal activity are coupled.

When an area of the brain is in use, bloodflow to that region increases, thereby indicating neural activity. This neural activity can be presented graphically by colour-coding the strength of activation across the brain or in specific brain regions. The technique can localise neural activity to within millimetres.

Functional MRI results revealed the following:

  • schizophrenic subjects had normal neural activity in the brain region responsible for decision-making (prefrontal cortex)
  • among schizophrenic subjects, brain regions responsible, in part, for controlling actions and choice (the caudate) had far lower neural activity than in healthy subjects
  • lower neural activity in the caudate regions was correlated with the difficulty that schizophrenic subjects' had applying their food preferences to obtain future snack foods.

"Pathology in the caudate and associated brain regions may prevent schizophrenic subjects from properly evaluating their desires then transmitting that information to guide their behavior," says Dr Morris.

"This means that desires and goals are intact in people with schizophrenia, however they have difficulty choosing the right course of action to achieve those goals.

"This failure to integrate desire with action means people with schizophrenia are stuck in limbo, wanting a normal life but unable to take the necessary steps to achieve it."

Schizophrenia affects one per cent of people worldwide, including in Australia. However so-called "poor motivation" in schizophrenia is a major economic concern because it is not treated by current medicines, and often means patients fail to finish their education or hold a full-time job.


'/>"/>

Contact: Dan Gaffney
daniel.gaffney@sydney.edu.au
61-481-004-782
University of Sydney
Source:Eurekalert

Related medicine news :

1. Those with episodic amnesia are not stuck in time, says philosopher Carl Craver
2. US Drug Watchdog Now Urges All Metal on Metal Hip Implant Failure Victims To Get A New Opinion From Another Orthopedic Surgeon Before They Get Stuck With a New Problem
3. US Drug Watchdog Now Urges All Women Stuck with a Failed Transvaginal Mesh Product Failure to Call Them for Names of National Caliber Attorneys
4. Stuck in the throat
5. Chinese Drywall Complaint Center Now Demands Leadership From Obama & EPA, For Homeowners In Florida And In The US Southeast Stuck In Toxic Chinese Drywall Hell-Forward?
6. Dr. Patrick Walsh, Director of the Marianjoy Psychology Department Appointed to the State of Illinois Brain and Spinal Cord Injury Advisory Council
7. Bats bolster brain hypothesis, maybe technology, too
8. New non-invasive technique controls size of molecules penetrating the blood-brain barrier
9. Researchers Pinpoint Brain Region Where Contextual Memories Are Made
10. Decline in daily functioning related to decreased brain activity in Alzheimers
11. Researchers Create Functional 3-D Brain-Like Tissue
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/7/2016)... ... , ... AlignLife clinics nationwide are giving back to their communities by collecting ... bountiful gifts wrapped tightly under a Christmas Tree. AlignLife hopes to spread the ... , In exchange for generous donations, customers will receive a gift in return. ...
(Date:12/7/2016)... ... December 07, 2016 , ... Sharon Kleyne, host of the ... and Your Health on Voice of America, declared on her radio program in November ... the fact that when these bullies attack leaders in corporate America, they are trying ...
(Date:12/7/2016)... ... , ... Delete® - Tattoo Removal and Laser Salon Offers Delightful Holiday Deals ... To 33% Off Botox® and Juvederm® Products Now Through December 31, 2016 , Delete® ... Deals on Botox® and Juvederm® just in time for the holiday party season. ...
(Date:12/7/2016)... ... 2016 , ... The medical profession is well aware that heart attacks do ... analyzing heart attacks among 138,602 people recorded a 35% higher number of heart attacks ... agree of course–no time of year is a good time for a heart attack! ...
(Date:12/7/2016)... ... December 07, 2016 , ... ... its newest portable bioelectronic medicine device WellnessPro Plus for consumers and healthcare ... enhances the WellnessPro platform by expanding the treatment modalities available in a ...
Breaking Medicine News(10 mins):
(Date:12/7/2016)... 2016 According to responses from U.S. oncologists that ... of patients with non-small cell lung cancer (NSCLC), treatment decisions ... genetic mutation status. The findings of the survey were presented ... #P3.02b ) at the 2016 World Conference on Lung ... The survey results revealed an overall high rate of ...
(Date:12/7/2016)... Dec. 7, 2016 Boehringer Ingelheim today ... patients with unresectable malignant pleural mesothelioma (MPM) met ... data, presented at the 17 th IASLC ... Vienna , showed nintedanib plus pemetrexed/cisplatin demonstrated ... pemetrexed/cisplatin, with a significantly improved PFS (9.4 vs ...
(Date:12/7/2016)... YORK , December 7, 2016 ... Pharmaceuticals PLC (NASDAQ: JAZZ ), Anthera Pharmaceuticals Inc. ... DNAI ), and AveXis Inc. (NASDAQ: AVXS ... Sector Index fell roughly 37% to reach a level equal ... it is down by approximately 14% for the year, it ...
Breaking Medicine Technology: