People argue constantly about the role of specific brain changes in affecting human behavior. As you probably know if you’re a frequent A3 reader, I’m a big believer in the notion that just like every other physical aspect of our “selves,” biological changes in our brain function brought about by genetics, experience, or other influences have a huge effect on how we think.
Apparently, researchers just found at least one aspect of brain function that can make us exaggerate our perception of our own negative responding.
The story here is pretty compelling –
In rats, a specific neurotransmitter system, called NPS (or neuro-peptide S) has been implicated in anxious responding and fear. Later research in humans revealed that a specific variation in one of the genes that plays a role in this system, NPSR1T (the T version of the neuro-peptide S receptor subtype 1), is associated with panic disorder.
The most recent piece of the puzzle, published in the journal Molecular Psychiatry, has revealed that humans that carry 1 copy of this variation have significantly stronger evaluations of their own negative responses to a standard fear-conditioning experiment. Essentially they “catastrophized” their own reaction to an experimental fear-associated signal. Also, this catastrophe registered in a very specific part of their brain called the rostral dorsomedial prefrontal cortex (dmPFC), an area that supports the explicit, conscious appraisal of threat stimuli (see picture on the left).
One of the most interesting pieces in my opinion is this – These individuals had no elevation in their physiological fear responses either in skin response, heart rate, or the brain areas known to be associated with them.
Apparently, just because you believe that something is worst than someone else doesn’t mean that your body responds to it that way. Pretty cool!
K A Raczka, N Gartmann, M-L Mechias, A Reif, C Büchel, J Deckert and R Kalisch (2010). A brain area for catastrophizing. Molecular Psychiatry 2010 15: 1045.
K A Raczka, N Gartmann, M-L Mechias, A Reif, C Büchel, J Deckert and R Kalisch (2010). A neuropeptide S receptor variant associated with overinterpretation of fear reactions: a potential neurogenetic basis for catastrophizing. Molecular Psychiatry 2010 15: 1067-1074.