The underdevelopment of connections in the brain after age 30 may be a predictor of future mental health problems.
Drs. Raluca Petrican and Cheryl Grady, both at the Rotman Research Institute in Toronto, Canada, conducted the study. Their findings were published in The Journal of Neuroscience.
In the area of psychology, inhibition is the ability to tune out all other stimuli and focus on one particular stimulus. The brain network is susceptible to dispositional and situational influences: the former explain behaviors that are caused by characteristics that exist within the person, and the latter are those that are external to the individual and stem from the environment.
"Thus, the neural signature of a cognitive or affective predisposition can vary significantly across different task contexts," say the authors of the new study.
Drs. Petrican and Grady aimed to test whether age and the influence of environmental factors would have an impact on the neural networks associated with inhibition.
The pair examined functional MRI data from 359 individuals aged between 22 and 36 years, all of whom were involved in the Human Connectome Project to observe whether patterns of brain connectivity linked with inhibition remain stable across different contexts and over time.
Brain connectivity differs through adulthood
Their findings indicated that patterns of connectivity differ between early and middle adulthood. Furthermore, patterns of connectivity vary depending on task. For example, pattern changes were identified between a task that tested working memory and one that required the participants to process social and financial rewards.
These results suggest that the underlying neural basis of inhibition differs depending on the age and circumstances of each individual.
Patterns of neural connectivity change between early adulthood and later adulthood. During later adulthood, fewer specialized brain regions are utilized, which may enable more efficient processing of information.
The researchers found that study participants over the age of 30 who did not exhibit a strong presence of the brain pattern associated with later adulthood had a greater risk of reporting psychological traits connected with anxiety, aggression, attention, and depression.
"Our results suggest that the neural dynamics within networks linked to internal cognition and those involved in environmentally driven control differentiate individuals with higher from those with lower inhibition across a variety of contexts."
"Our findings also point to the distinct processes engaged by individuals with superior inhibitory control during high cognitive load versus high reward value contexts and, as such, they shed some light on the unique mechanisms through which cognitive control may impact cognitive versus social-affective performance," they add.
Overall, the findings by Drs. Petrican and Grady suggest that inhibition develops in later adulthood, and this later development is fundamental to healthy psychological functioning and mental health during mid-adulthood.