Maxim Kireev

In present research, the brain maintenance of the error detection mechanism was studied in resting condition and while subjects consciously implemented incorrect actions (i.e. deception). Assessment of the regional cerebral blood flow revealed involvement of anterior cingulated cortex in deception. The obtained data indicate that it is impossible to consciously control the activity of the error detection mechanism. PET study of patients with obsessive compulsive disorder in resting condition revealed a decrease of brain glucose metabolism in the anterior cingulated cortex in comparison with healthy subjects. These data pointed to malfunctioning of the error detection mechanism. The findings support the formerly proposed hypothesis about the impact of the error detection mechanism in formation and support of obsessive compulsive disorder.

In the present article the features of the functional activity of the anterior cingulate cortex (ACC), a key element of neuroanatomical brain system of an error detection, in drug-resistant forms of obsessive-compulsive disorder (OCD) are discussed on a basis of both original and literature data. Available data indicate the presence of functional deficit in the ACC during OCD. This allows to suggest that functions of the ACC in OCD patient are partially redistributed between other brain areas. Thus in contrast to the previously accepted notion, the ACC as the target ofstereotactic surgery for OCD is pathologically altered brain region. Probably this is the reason why stereotactic destruction of ACC does not lead to significant changes in the patient's psyche. The essence of the pathological reorganisation of the functional activity of the brain in OCD remains unclear and requires further investigation.

ABSTRACT The goal of the study was analysis of the cerebral mechanisms of deliberate deception. The eventrelated functional magnetic resonance (ER fMRI) imaging technique was used to assess the changes in the functional brain activity by means of recording the blood oxygen level-dependent (BOLD) signal. Twelve right-handed healthy volunteers aged 19–44 years participated in the study. The BOLD images were obtained during three experimental trials: deliberate deception, manipulative honest and control truthful trials (catch trials). The deliberate deception and manipulative honest actions were characterized by a BOLD signal increase in the anterior cingulate (Brodmann’s area (BA) 32), frontal (BAs 9/10, 6), and parietal (BA 40) cortices as compared with a truthful response. Comparison of the ER fMRI data with the results of earlier studies where event-related potentials (ERPs) were recorded under similar conditions indicates the involvement of the brain mechanism of error detection in deliberate deception.