Scientists have identified a 'Horror film gene that makes some scream while others laugh', The Daily Telegraph reports. Results from a study of 96 women in Germany found that women who had two copies of one version of a gene called COMT 'were significantly more startled by frightening images' than women who didn t, the newspaper says.
This study used a test to measure how women responded to a startling burst of noise when shown pleasant, unpleasant or neutral images. Although this test is an accepted way of testing fear response, it is not clear how closely it resembles real-life fearful situations, or even watching horror movies. As the authors of the study point out in the news reports, anxiety and fear are complex emotions which will be affected by more than one genetic variation. Environmental factors will also play an important role.
Where did the story come from?
Drs Christian Montag, Martin Reuter and colleagues from the University of Bonn and other universities in Germany, Denmark and the US carried out this research. No sources of funding were reported for this study. It was published in the peer-reviewed scientific journal: Behavioural Neuroscience.
What kind of scientific study was this?
This was a cross-sectional study looking at the association between a genetic variation in the COMT gene and people s brain activity when processing fear. The COMT gene encodes a protein that breaks down one of the chemicals used to communicate by nerve cells in the brain. The main genetic variation that the researches were interested in leads to a change in the 158th amino acid (building block) in the chain that makes up this protein, changing it from an amino acid called valine (Val158) to an amino acid called methionine instead (Met158). The Met158 variation means that the protein cannot breakdown the communication chemical as effectively, and this has been found to be associated with anxiety in some studies, although not others.
The researchers selected 101 white female participants of German origin (average age 22 years) from their database of healthy people who had volunteered to take part in behavioural research. In order to be included on the database, the volunteers had to report no symptoms of mental health disorders or neurological diseases. All database participants provided cheek swabs for extraction of DNA, and the DNA was tested for known genetic variations thought to be potentially related to behavioural traits, including the COMT variation.
The researchers selected people who had two, one or no copies of the COMT Met158 variation (each person has two copies of the COMT gene). The selected participants then took part in the 'affective startle response modulation' test or ASRM. The ASRM was reported to be a standard test of fear processing, and other studies have shown that people with anxiety disorders and those with anxious temperament have enhanced responses on the ASRM.
