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Patients with schizophrenia show deficits in cognitive functioning, and studies on cerebral hemodynamics have revealed aberrant patterns of mean cerebral blood flow velocity (MFV), an equivalent of cerebral blood flow (CBF). Therefore, we carried out a controlled study that assessed MFV in schizophrenia during a well-known neuropsychological task, the Trail Making Test (TMT). We measured MFV in the middle cerebral arteries using functional transcranial Doppler sonography in 15 schizophrenia patients and 15 healthy subjects. In comparison to healthy subjects, patients performed poorer on the TMT-A and the TMT-B, and there was increased cerebral blood flow velocity during the TMT-B. A comparison of subgroups of patients and controls matched in performance on the TMT-B revealed that these patients still showed significantly increased cerebral blood flow velocity. Increased MFV in schizophrenia suggests specific alterations of cerebral hemodynamics during the Trail Making Test, Part B, which are not detectable during visuomotor activity, and which are independent of performance. These findings emphasize the pathophysiological importance of cognitive functioning in schizophrenia, but cast doubts whether performance in this particular test plays a relevant role for CBF abnormalities in schizophrenia. [ABSTRACT FROM AUTHOR]

Cognition–emotion interaction in the brain can be investigated by incorporating stimuli with emotional content into cognitive tasks. Emotional stimuli in the context of a working memory (WM) task yield increased activation in WM-related lateral prefrontal regions, whereas cognitive effort enhances deactivation in emotion-related cortical midline regions. N-methyl- d -aspartate glutamate receptors (NMDA-Rs) are critically involved in WM, and NMDA-R antagonists, such as ketamine, accordingly affect WM but also have a profound impact on emotional processing, as underscored by the rapid reduction of depressive symptoms after administration of a single dose of ketamine. The effect of ketamine on both cognitive and emotional processing therefore makes it a useful tool to further explore cognition–emotion interaction in the brain. Twenty-three healthy subjects were administered ketamine to investigate whether its effects on WM performance and brain reactivity depend on emotional content or emotional valence of stimuli. Furthermore, we aimed at investigating how ketamine affects the integration of emotion and WM processes in emotion-related cortical midline regions and WM-related lateral prefrontal regions. Results show that ketamine modulates cognition–emotion interaction in the brain by inducing lateralized and valence-specific effects in emotion-related cortical midline regions, WM-related lateral prefrontal regions and insula. In emotion-related cortical midline regions ketamine abolishes enhancement of deactivation normally observed during cognitive effort, while in the right DLPFC and the left insula the previously described pattern of increased activation due to emotional content is abrogated exclusively for negative stimuli. Our data therefore shows a specific effect of ketamine on cognition–emotion interaction in the brain and indicates that its effect on amelioration of negative biases in MDD patients might be related to less interference of cognitive processing by negative emotional content. [ABSTRACT FROM AUTHOR]

Abstract: Functional Transcranial Doppler sonography (fTCD) has been applied to assess peak mean cerebral blood flow velocity (MFV) with a high temporal resolution during cognitive activation. Yet, little attention has been devoted to gender-related alterations of MFV, including spectral analysis. In healthy subjects, fTCD was used to investigate a series of cerebral hemodynamic parameters in the middle cerebral arteries (MCA) during the Trail Making Tests (TMT), a means of selective attention and complex cognitive functioning. In females, there was a frequency peak at 0.375Hz in both MCA, and we observed a dynamic shift in hemispheric dominance during that condition. Further, after the start phase, there was an MFV decline during complex functioning for the entire sample. These novel results suggest condition-specific features of cerebral hemodynamics in females, and it adds to the notion that gender is a fundamental confounder of brain physiology. [Copyright &y& Elsevier]

Abstract: Set shifting provokes specific alterations of cerebral hemodynamics in basal cerebral arteries. However, no gender differences have been reported. In the following functional transcranial Doppler study, we introduced cerebral hemodynamic modulation to the aspects of set shifting during Wisconsin Card Sorting Test (WCST). Twenty-one subjects underwent the WCST during insonation of the middle cerebral arteries. We examined gender effects on task performance and cerebral hemodynamic modulation. Further, we investigated the linkage between performance and cerebral hemodynamic modulation. In females, maximum positive modulation was restricted to the behaviorally relevant time point of set shifting, and there were time-locked associations between mental slowing during set shifting and rapid cerebral hemodynamic modulation exclusively in females. This study provides evidence of gender-related cerebral hemodynamic modulation during set shifting, and we detected time-locked brain–behavior relationship during cognitive control in females. [Copyright &y& Elsevier]

Abstract: Emotions are frequently characterized by distinct dimensions such as valence, intensity, and recognition. However, the exact neural representation of these dimensions in different prefrontal cortical regions remains unclear. One of the problems in revealing prefrontal cortical representation is that the very same regions are also involved in cognitive functions associated with emotion processing. We therefore conducted an fMRI study involving the viewing of emotional pictures (using the International Affective Picture System; IAPS) and controlled for associated cognitive processing like judgment and preceding attention. Functional activation was correlated with subjective post-scanning ratings of valence, intensity, and recognition. Valence significantly correlated with the functional response in ventromedial prefrontal cortex (VMPFC) and dorsolateral prefrontal cortex (DLPFC), intensity with activation in ventrolateral prefrontal cortex (VLPFC) and dorsomedial prefrontal cortex (DMPFC), and recognition with the functional response in perigenual anterior cingulate cortex (PACC). In conclusion, our results indicate segregated neural representation of the different emotion dimensions in different prefrontal cortical regions. [Copyright &y& Elsevier]