Modulatory Effect Of Consciousness On Emotional Response Inhibition

ObjectiveResponse inhibition is an important component of executive function. The ability of response inhibition to negative events is crutial for human social adaption. Although numerous studies had focus on the emotional effect on response inhibition and its neural mechanism, it is hard to draw a conclusion about how emotion influences response inhibition in behavior and neural aspects.Thus, the present study aims to investigate the emotional response inhibition and neural mechanism in conscious and unconscious levels using implicit and explict emotional task. In addition, compared to controls, we explore if emotional disorders, such as general anxiety disorder and depression showed dissociated effect of emotion on response inhibition in conscious and unconscious conditions.Methods1. Thisty voluntary (15females) subjects in the study1were recruited from Anhui Medical University. In second and third study,11general anxiety disorders and11depressions (7females in each group) from Hefei Center for Mental Health were dioganosed by experted psychiatrist. Paired control participants were selected from The Anhui Medical University and The First Affiliated Hospital of Anhui Medical University. The participants were paired for gender, age and education between anxieties, depressions and controls. All participants in the three groups met the following exclusion criteria:(a) No current substance (including alcohol) abuse.(b) No brain damage.(c) Participants in control group with no mental disorder.(d) General anxiety disorders and depression with no other mental disorder. 2. Event-related brain potential (ERP):ERP records the brain evoked potential from skull surface by average superposition technology. ERP with high time resolution facilliate reseachers to investigate the time course of information processing in the brain and is frequently used for cognitive neuroscience research.Standardized low-resolution brain electromagnetic tomography (sLORETA):sLORETA with relatively accurate spatial localization is a three-dimensional discrete linear solution for the EEG inverse problem within specified time windows.3. Implicit and explicit tasks:Facial stimuli consisting of40sad and40neutral faces were selected from the native Chinese Facial Affective Picture System. The stimuli included20female and20male faces displaying each emotion type. In implicit task, participants were instructed to response or inhibit their behavior according to the facial gender. While in explicit task, they make theior decision based on facial expressions. Thus, implicit and explict task were matched in stimuli except experimental instructions.Results1. In study1, the amplitudes of Nogo-P3in explict negative conditions were significantly larger than that in implicit negative tasks. The results indicate emotional consciousness have effect on emotion-modulated response inhibition in the late procession stage.2. Nogo-P3amplitudes of general anxiety disorder were significantly lower than control group in implict negative conditions. However, the Nogo-P3amplitudes of depression participants were significantly smaller than controls in both implicit and explicit tasks. The results indicate that general anxiety disorder and depression show dissociative performance on modulated effect of emotion consciousness on response inhibition.3. Emotional response inhibition in implicit and explict tasks showed dissociative brain activative pattern. In implict task, right inferior frontal gyrus and right inferior frontal junction were activated for emotional response inhibition. Right inferior frontal gyrus was involved for conflict detection and mornitoring. Right inferior frontal junction was activated for behavior response inhibition. In explict task, the right frontal junction was recruited for the overall process for emotional response inhibition. In addition, the corelationship between right inferior frontal gyrus and anterior cingulated cortex was significant in explict task, but not in implict task, which confirmed that anterior cingulated cortex was a hub for the interaction between emotion and cognition in explict condition.4. The brain activation level of left inferior frontal gyrus was significantly higher in general anxiety disorder than in control in implict negative task. The activation of dorsal lateral prefrontal cortex was significantly higher in control group than in anxiety group. In addition, the corelationship between left inferior frontal gyrus and rostral anterior cingulated cortex was significant in negative Nogo condition in general anxiety disorder group. Further more, depression participants showed lower activation of dorsal lateral prefrontal cortex than control in all Nogo tasks. Current density of rostral anterior cingulated cortex of depression subjects was significantly smaller than that of control, which indicated abnormal function of dorsal lateral prefrontal cortex and rostral anterior cingulated cortex maybe pathophysiology mechanism for depression symptom.ConclusionsIn conclusion, electrophysiological data in the present study revealed that emotional response inhibition was modulated by emotion consciousness. In conscious and unconscious conditions, emotional response inhibition showed dissociative brain active pattern. Further more, patients with general anxiety disorder show significant deficits in unconscious emotional response inhibition. While patients with depresson disorder showed significant dificits in both conscious and unconscious conditions. In conclusion, the prefrontal-cingulate loops play a crucial role in emotional response inhibition. The different active pattern between patients under emotional response inhibition may offer objective evidence for the differential diagnosis and treatment between general anxiety disorder and depression.