
PREDRAG PETROVIC LAB
Cognitive Neuropsychiatry

What is Cognitive Neuropsychiatry ?
Cognitive neuroscience may be defined as research of all the processes that take place in the brain and create behavior. The core of cognitive neuroscience is to understand how networks including different brain areas process information on a human system level. It is translational as it brings many different research areas together. For example, cognitive neuroscience mixes psychological cognitive models of behavior together with brain imaging and computational models. The advances in imaging technology development (including functional and structural MRI, magnetic encephalography (MEG) and receptor positron emission tomography(PET) have contributed to an exponential increase in the understanding of how the human brain processes information.
Cognitive neuropsychiatry tries to apply the knowledge from cognitive neuroscience to psychiatry and thereby better understand what drives clinical disorders on a system level. Early models of psychiatric states, such as the dopamine hypothesis of psychosis or the serotonin model of depression, have often been oversimplified - and have therefore not had the potential to explain the underlying pathological mechanism. The main criticism is that they did not take into account how all the different nodes in the brain networks together contribute to behavior and the different disorders. Cognitive neuropsychiatry is a promising research field precisely since it is focusing on the interaction between all these areas. In other words, it offers complex models of psychiatric disorders.
In the present project I want to bring the field of cognitive neuropsychiatry forward on several areas including placebo effects, psychosis, depression and emotional dysregulation. The common nominator is a set of expectation processes that exist on a system level. Expectations processes can be found in all hierarchies in the brain and may be non-conscious or conscious. It has been proposed that they represent fundamental a principle of how the brain processes information. In short, the brain compares all new inputs with previously stored information (i.e. expectations). If the expectations don’t match with the input the brain constructs error-signals. These are fed forward in the brain and can change the knowledge of the brain. Without this process the brain would never be able to learn or adapt to new environments. Expectations and error signals can also modulate how incoming information is processed. Thus, they have a direct impact on how we understand and experience the world. As will be shown below it seems that this process may be crucially involved in several psychiatric states and treatments. Expectation processes have the potential to explain the effect of placebo treatments, and the mechanisms underlying psychosis, depression and emotional dysregulation. In order to understand how expectations relate to brain function and psychiatric states we plan to use several functional imaging techniques, e.g. functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and magnetoencephalography (MEG), which are present at Karolinska Institutet. We have been using functional imaging techniques over 15 years.