Nicotinic antagonist effects on functional attention networks.

Cholinergic neurotransmission has been implicated in memory and attention. We investigated the effect of the non-competitive nicotinic antagonist mecamylamine on three components of attention processes (i.e.

General and specific responsiveness of the amygdala during explicit emotion recognition in females and males.

Background: The ability to recognize emotions in facial expressions relies on an extensive neural network with the amygdala as the key node as has typically been demonstrated for the processing of fearful stimuli. A sufficient characterization of the factors influencing and modulating amygdala function, however, has not been reached now. Due to lacking or diverging results on its involvement in recognizing all or only certain negative emotions, the influence of gender or ethnicity is still under debate.

Amygdala activation during recognition of emotions in a foreign ethnic group is associated with duration of stay.

Cultural differences in emotion recognition performance have frequently been reported, whereby duration of stay in a foreign culture seems to be a crucial factor. Furthermore, cultural aspects influence the neural correlates of face and emotion processing thereby also affecting the response of the amygdala. Here, the exposure to a foreign culture and its influence on the cerebral correlates of facial emotion recognition were examined in 24 Asian and 24 age-matched European males.

Amygdala activity to fear and anger in healthy young males is associated with testosterone.

Neuroimaging studies have documented modulation of the activity of the amygdala - a key node in the neural network underlying emotion perception and processing, and one that has also been associated with regulating aggression - by exogenous testosterone. However, results on the impact of normal range testosterone levels on explicit emotion recognition as a prerequisite for social interaction and amygdala activation in healthy young males are missing. Hence, we performed functional MRI at 3T in a group of 21 healthy males during explicit emotion recognition with a protocol specifically optimized to reliably detect amygdala activation.

Generalized deficit in all core components of empathy in schizophrenia.

Empathy is a multidimensional construct composed of several components such as emotion recognition, emotional perspective taking and affective responsiveness. Patients with schizophrenia demonstrate deficits in several domains of emotion processing and perspective taking, thus suggesting a dysfunctional emotional competence. We assessed empathic abilities via three paradigms measuring emotion recognition, perspective taking and affective responsiveness as well as self-report empathy questionnaires in 24 (12 females, 12 males) schizophrenia patients meeting the DSM-IV criteria for schizophrenia and 24 matched healthy volunteers.

Differential brain activation during facial emotion discrimination in first-episode schizophrenia.

Background: Aberrant brain activation during facial emotion discrimination has been described in chronic schizophrenia, while little is known about early stages of the illness. The aim of the current study was to investigate valence-specific brain activation of emotion discrimination in first-episode schizophrenia. These patients provide the advantage of lacking the effects of long-term medication and chronic illness course and can hence further enhance the understanding of underlying psychopathological mechanisms.

Cerebral dysfunctions of emotion-cognition interactions in adolescent-onset schizophrenia.

Objective: Schizophrenia is among the most severe of psychiatric disorders, leading to impairments of affective and cognitive abilities. These dysfunctions affect each other mutually. Adolescent-onset schizophrenia (AOS) constitutes a particularly severe form of the disorder.

Neuregulin 1 ICE-single nucleotide polymorphism in first episode schizophrenia correlates with cerebral activation in fronto-temporal areas.

The Neuregulin (NRG1) gene has been associated with schizophrenia, but its functional implications are largely unknown. Our aim was to assess differential brain activation between patients carrying an at-risk allele on the Neuregulin 1 gene and patients without this genetic risk. Neural signal changes between 14 first episode schizophrenia patients with the at risk allele (SNP8NRG221533) from the Icelandic core haplotype and 14 without were measured with fMRI during a working memory task.

Mood induction with olfactory stimuli reveals differential affective responses in males and females.

Olfactory perception is characterized by interpersonal variability. Although gender has been identified as a potential influencing factor, currently little is known about its effect on perceived hedonicity of individual odorants. This study assessed gender differences in emotional appraisal of 3 odorants (eugenol, vanillin, and hydrogen sulfide [H(2)S]), presented to 25 healthy subjects (13 males, 12 females) in a blocked design.

Facial emotion recognition and amygdala activation are associated with menstrual cycle phase.

Converging evidence has accumulated that menstrual cycle and thus hormonal levels can affect emotional behavior, in particular facial emotion recognition. Here we explored the association of ovarian hormone levels and amygdala activation during an explicit emotion recognition task in two groups of healthy young females: one group was measured while in their follicular phase (n=11) and the other during their luteal phase (n=11). Using a 3T scanner in combination with a protocol specifically optimized to reliably detect amygdala activation we found significantly stronger amygdala activation in females during their follicular phase.

Neuronal correlates of facial emotion discrimination in early onset schizophrenia.

Emotion discrimination deficits represent a well-established finding in schizophrenia. Although imaging studies addressed the cerebral dysfunctions underlying emotion perception in adult patients, the question of trait vs state characteristics is still unresolved. The investigation of juvenile patients offers the advantage of studying schizophrenia at an age where influences of illness course and long-term medication are minimized.

Structural brain abnormalities in psychopaths-a review.

The biological basis of psychopathy has not yet been fully elucidated. Few studies deal with structural neuroimaging in psychopaths. The aim of this article is to review these studies in order to contribute to our understanding of the biological basis of psychopathy.

Deformation field morphometry reveals age-related structural differences between the brains of adults up to 51 years.

Age-related differences in the anatomical structure of the brains from 51 healthy male subjects (age: 18-51 years) were analyzed by deformation field morphometry in a cross-sectional study. The magnetic resonance images of the brains were nonlinearly registered onto the image of a reference brain: the registration algorithm simulated an elastic deformation of each brain (source brain) so that the voxelwise intensity differences with the reference brain were minimized. A three-dimensional deformation field was calculated for each source brain that encoded the anatomical differences between the source brain and the reference brain.

Increased neural response related to neutral faces in individuals at risk for psychosis.

Objective: The reliable discrimination of emotional expressions in faces is essential for adequate social interaction. Deficits in facial emotion processing are an important impairment in schizophrenia with major consequences for social functioning and subjective well-being. Whether neural circuits underlying emotion processing are already altered before illness onset is yet unclear.

Emotion recognition accuracy in healthy young females is associated with cycle phase.

Several studies reported a significant influence of ovarian hormone status on cognition and person perception. In particular, it has been stated that female mating preferences are shifted during the menstrual cycle. It remains, however, unclear if facial emotion recognition, a prerequisite for successful social interaction, is also influenced by estradiol and progesterone levels.

Gender differences in the cognitive control of emotion: An fMRI study.

The interaction of emotion and cognition has become a topic of major interest. However, the influence of gender on the interplay between the two processes, along with its neural correlates have not been fully analysed so far. In this functional magnetic resonance imaging (fMRI) study we induced negative emotion using negative olfactory stimulation while male (n=21) and female (n=19) participants performed an n-back verbal working memory task.

Neural substrates of olfactory processing in schizophrenia patients and their healthy relatives.

Odorants represent powerful stimuli capable of eliciting various emotional responses. In schizophrenia patients and their non-affected relatives, olfactory and emotional functions are impaired, revealing a familial influence on these deficits. We aimed at determining the neural basis of emotional olfactory dysfunctions using odors of different emotional valence for mood induction and functional magnetic resonance imaging (fMRI) by comparing 13 schizophrenia patients, their non-affected brothers and 26 matched healthy controls.

Stability of emotional dysfunctions? A long-term fMRI study in first-episode schizophrenia.

Objective: Patients with schizophrenia are characterized by emotional symptoms such as flattened affect which are accompanied by cerebral dysfunctions. This study aimed at determining changes of mood-related neural correlates under standardized pharmacological therapy in first-episode schizophrenia.

Method: Using fMRI in a longitudinal approach, 10 first-episode schizophrenia patients (6 males) and 10 healthy subjects (same education, gender and age) were investigated during sad and happy mood induction using facial expressions.

The influence of olfactory-induced negative emotion on verbal working memory: individual differences in neurobehavioral findings.

The influence of emotion on cognition plays an important role in people's everyday life as well as in psychiatric and neurological disorders. The present study used fMRI to examine the neural correlates of cognitive-emotional interactions and its inter-individual differences. Twenty-one healthy males performed a 0-back/2-back task while negative or neutral emotion was induced by negative/neutral olfactory stimulation.

Amygdala activation and facial expressions: explicit emotion discrimination versus implicit emotion processing.

Emotion recognition is essential for social interaction and communication and is a capacity in which the amygdala plays a central role. So far, neuroimaging results have been inconsistent as to whether the amygdala is more active during explicit or incidental facial emotion processing. In consideration of its functionality in fast automatic evaluation of stimuli and involvement in higher-order conscious processing, we hypothesize a similar response to the emotional faces presented regardless of attentional focus.

A special role of negative emotion in children and adolescents with schizophrenia and other psychoses.

Emotional impairments are apparent at an early stage in schizophrenia. While emotion processing has been studied intensively in adult patients, investigations focusing on children and adolescents with psychoses are rare. Emotion probes for mood induction and emotion discrimination that have been standardized in healthy subjects and applied to adult schizophrenia patients were evaluated in young patients (11-20 years).

Neural correlates of working memory dysfunction in first-episode schizophrenia patients: an fMRI multi-center study.

Working memory dysfunction is a prominent impairment in patients with schizophrenia. Our aim was to determine cerebral dysfunctions by means of functional magnetic resonance imaging (fMRI) in a large sample of first-episode schizophrenia patients during a working memory task. 75 first-episode schizophrenia patients and 81 control subjects, recruited within a multi-center study, performed 2- and 0-back tasks while brain activation was measured with fMRI.

Interaction of negative olfactory stimulation and working memory in schizophrenia patients: development and evaluation of a behavioral neuroimaging task.

Negative affect plays a crucial role in the psychopathology of schizophrenia. Although it is known that negative emotion has a strong effect on cognitive performance, this interaction has mainly been studied in healthy volunteers. Hence, working memory was assessed in 24 schizophrenia patients and 24 matched comparison subjects with a 0-back/2-back continuous performance test.

Impairment in the specificity of emotion processing in schizophrenia.

Objective: Deficits in emotion processing are a hallmark of schizophrenia, with consequences for social functioning and subjective well-being. However, their specificity and characteristics have not been ascertained psychometrically. The authors' purpose was to examine a differential deficit for processing emotional facets of the face compared to judgment of nonemotional features (age) and facial memory.

Dependence of amygdala activation on echo time: results from olfactory fMRI experiments.

Echo time dependence of the BOLD sensitivity is an important topic in fMRI whenever brain regions are considered where the EPI data quality suffers from susceptibility gradients. Here, an fMRI study is presented showing that a reduced echo time EPI sequence significantly enhances the statistical inference in subcortical (limbic) brain regions, with special focus on the amygdala. As a consequence, to facilitate whole-brain fMRI with optimal echo times, a sequence with slice-dependent echo time is demonstrated with a focus on structures suffering from susceptibility changes.