Post doc Marco Hirnstein
Brain stimulation and the left and right brain.
Our brain consists of two halves (left and right) which are specialized for a number of tasks. For example, we talk mostly with our left brain and recognize faces mostly with our right brain. The left brain is also specialized for carrying out fine motor skills. And since the left brain controls the right hand, most of us are right-handers.
Handedness and schizophrenia
My first research focus lies on why this specialization of the left and right brain half developed and how it is related to schizophrenia. Recently, I showed that patients with schizophrenia are not as strongly right-handed as control individuals. Since handedness and schizophrenia are hereditary, at least to some extent, this result suggests that similar genes are involved in handedness and schizophrenia.
There are many other links between schizophrenia and the specialization of our two brain halves. By better understanding these links I hope to find out more about how and why schizophrenia developed.
The second focus of my research is non-invasive brain stimulation. “Non-invasive” means I use magnetic fields or electrodes attached to the head to stimulate nerve cells in the brain – I do not perform any sort of brain surgery. The induced electricity is so weak and brief that most people do not even notice they are being stimulated. Nevertheless, the stimulation allows me to increase or decrease the activity in certain brain areas.
From previous experiments we know that brain areas devoted to language comprehension are often over-active in patients with schizophrenia. As a result, the patients experience hallucinations. On the other hand, brain areas devoted to reasoning and attention are often not active enough. As a result, patients often feel disorganized and cannot concentrate. I want to find out whether non-invasive brain stimulation has the potential to help schizophrenia patients to reduce the hallucinations and, at the same time, improve their ability to concentrate.
Hirnstein, M., & Hugdahl, K. The excess of non-right-handedness in schizophrenia: A meta-analysis of sex effects and potential biases in handedness assessment. British Journal of Psychiatry, in press.