Showing posts with label fMRI. Show all posts
Showing posts with label fMRI. Show all posts

Thursday, January 10, 2013

Proximity to Parent Reduces Anxious Youth Stress Response

Functional magnetic resonance imaging provides a powerful tool for understanding anxiety in children as well as adults.

This technique does not use any form of radiation and presents minimal risk for research participants.  We are beginning to better understand important mechanisms of childhood anxiety.

An innovative study of neural stress markers in children examined an important variable in childhood anxiety.  When children are studied in an fMRI scanner, they may or may not have a parent accompany them into the scanner room.  It is important to understand how parental proximity affects the anxiety tasks used in children.

Conner and colleagues from the University of Pittsburgh, Cal-Berkeley and the University of Virginia recently published a study related to this topic in the journal PLOS One. 

In their study, children with clinical anxiety underwent an anxiety task in the fMRI scanner.  Children were allowed to request that their accompanying parent stay with them in the scanner room.  If they did not request this, their parents waited in a external room during the period of the scanning. 

Children in the scanner were presented a series of words that included words with a cognitive element of physical danger, i.e. ghost, social anxiety, positive emotions and neutral words.  Children rated each word as positive, negative or neutral using a three-button glove.

The key findings from the study comparing 10 anxious children with parents in the scanning room, 10 anxious children with parents in the waiting room and 10 non-anxious control children with parents in the waiting room:
  • Anxious children with parents in the waiting room showed increased brain response compared to control children to anxiety words in three areas known to be related to stress response: hypothalamus, the ventromedial prefrontal cortex and the left ventrolateral prefrontal cortex
  • This stress response was attenuated in anxious children with parents in the scanning room.  Their level of response was very similar to control children.
The figure at the right highlights the medial frontal cortex.  This area was found to be important in the child stress response in the current study and is sensitive to parental proximity.

The authors of this study concluded that for anxious youth, "caregivers may act as emotion regulators".  They note that treatments that facilitate transfer of emotional regulation of anxiety from parental support to an internal self-mechanism may play a key role in advancing  anxiety disorder treatment in children.

Another important implication in this study is the potential role of parental proximity in comparing imaging studies across research centers.  Disparate results may be related to differing rates of parental proximity between research centers.

It is important to note this study did not use a randomized design as children were allowed to self-select whether they had a parent in the scanning room.  Nevertheless, this study proposes a brain mechanism related to a parental role in anxiety regulation for children who suffer from an anxiety disorder.  Interested readers can access the free full text of this manuscript by clicking on the link in the citation below.

Photo of blue curaco from San Diego Zoo from the author's files.

Image of prefrontal cortex is a screenshot from the iPad app 3D Brain.

Conner OL, Siegle GJ, McFarland AM, Silk JS, Ladouceur CD, Dahl RE, Coan JA, & Ryan ND (2012). Mom-It Helps When You're Right Here! Attenuation of Neural Stress Markers in Anxious Youths Whose Caregivers Are Present during fMRI. PloS one, 7 (12) PMID: 23236383

Monday, December 24, 2012

Top Ten Brain Posts 2012: #9 Antisocial Brain

The number nine most viewed post at Brain Posts for 2012 was a post looking at a research study of brain imaging in antisocial personality disorder.

This study used a functional magnetic resonance imaging technique known as functional connectivity.  The study compared a group of adolescents with a history of physical or sexual assault compared to control adolescents.

The compared the connectivity between brain regions between the antisocial group and control groups along with psychometric scores on empathy and impulsivity.  Antisocial groups tend to show low scores on empathy and high scores on impulsivity.

No brain connectivity differences were found for those with low empathy scores.  However, high impulsivity scores in the antisocial group was linked to reduced connectivity between the brain regions of executive function and control (frontal cortex) and the brain regions of behavior and self-referential cognition.  The authors concluded that adolescent antisocial impulsivity appears to be linked to a delayed maturation of brain circuits linking executive function, self-cognition and behavior.

In a second post on brain imaging study, I reviewed a study showing children with markers for antisocial personality risk showed reduced amygdala response to viewing sad faces.  This brain response may contribute to the lack of social empathy development in those who later emerge with adult antisocial behavior.

Readers with more interest in this topic are invited to click on the link to the original posts were full access is available to the full research manuscripts at the PMID link located at the bottom of the post.

Photo of lorikeet from Tampa Busch Gardens aviary in Tampa, FL from the author's files.