WHAT IS THE BRAIN’S INSULA?
The insula is a small region of the brain’s cerebral cortex (see diagram below). Its precise function is not fully understood but it is hypothesized to play a significant role in :
- generating our conscious self-awareness of our emotions.
- interoceptive processing (this refers to the degree to which we are paying attention to the sensory information generated by our bodies).
- how the above 2 functions interact to generate our perception of the present moment.
STUDY ON HOW CHILDHOOD TRAUMA ADVERSELY AFFECTS THE INSULA :
A study conducted at the Stanford University School of Medicine involved 59 participants who were aged between 9- years-old and 17-years-old.
These 59 participants comprised 2 groups :
GROUP 1 (The Traumatized Group): This group comprised 30 young people (16 males and 14 females).
Of these 30 participants, 5 had been exposed to one traumatic stressor in childhood, whilst the other 25 had been exposed to two or more traumatic stressors or to ongoing/chronic traumatic stress during childhood.
All 30 participants of this group had exhibited symptoms of posttraumatic stress disorder (PTSD).
GROUP 2 : (The Non-Traumatized Group): This group was the ‘control’ group and comprised the remaining 29 participants.
None of the 29 participants in this group exhibited symptoms of posttraumatic stress disorder (PTSD).
WHAT BRAIN SCANS REVEALED ABOUT THE PARTICIPANTS IN EACH OF THE TWO GROUPS :
The brains of all 59 participants were scanned using a technique known as structural magnetic resonance imaging (sMRI).
In the NON-TRAUMATIZED GROUP (GROUP 2) there was found to be NO DIFFERENCE in the structure of the insulae when the males were compared to the females.
In the TRAUMATIZED GROUP (GROUP 1) there WAS FOUND TO BE A DIFFERENCE in the structure of the insulae when the males were compared to the females. The difference was as follows :
a) Boys in the TRAUMATIZED GROUP (GROUP 1) had insulae of a GREATER VOLUME AND SURFACE AREA than the boys in the NON-TRAUMATIZED GROUP (GROUP 2).
b) Girls in the TRAUMATIZED GROUP (GROUP 1) had insulae of a LESSER VOLUME AND SURFACE AREA than the girls in the NON-TRAUMATIZED GROUP (GROUP 2).
WHAT CAN WE CONCLUDE FROM THESE FINDINGS?
We are able to draw two main inferences based upon the above observations; these are :
a) the experience of significant childhood trauma adversely affects the structural development of the insula.
b) the way in which the experience of significant childhood trauma adversely affects the structural development of the insula. differs between boys and girls.
IMPLICATIONS FOR TREATMENT OF PTSD :
The above findings imply that because the effects of traumatic stress on the brain appear to differ between males and females, the type of treatment provided for individuals with PTSD needs to take into account their sex.
David Hosier BSc Hons; MSc; PGDE(FAHE).