Matthias Gamer

Bio: Matthias Gamer is an academic researcher from University of Würzburg. The author has contributed to research in topics: Gaze & Psychology. The author has an hindex of 36, co-authored 119 publications receiving 3960 citations. Previous affiliations of Matthias Gamer include University of Mainz & Eppendorf (Germany).

Different amygdala subregions mediate valence-related and attentional effects of oxytocin in humans.

Abstract: The neuropeptide oxytocin enhances the processing of positive social stimuli and improves the capacity to effectively attend the eye region of conspecifics. To investigate the neural basis of these effects, we combined intranasal oxytocin administration with high-resolution functional magnetic resonance imaging in a unique emotion classification task. Emotional faces were briefly presented while controlling for the initial fixation, and measuring subsequent eye movements. Oxytocin had differential effects on the activity of specific amygdala subregions. On the one hand, it attenuated activation in lateral and dorsal regions of the anterior amygdala for fearful faces but enhanced activity for happy expressions, thus indicating a shift of the processing focus toward positive social stimuli. On the other hand, oxytocin increased the likelihood of reflexive gaze shifts toward the eye region irrespective of the depicted emotional expression. This gazing pattern was related to an increase of activity in the posterior amygdala and an enhanced functional coupling of this region to the superior colliculi. Thus, different behavioral effects of oxytocin seem to be closely related its specific modulatory influence on subregions within the human amygdala.

Amygdala Activation Predicts Gaze toward Fearful Eyes

Abstract: The human amygdala can be robustly activated by presenting fearful faces, and it has been speculated that this activation has functional relevance for redirecting the gaze toward the eye region. To clarify this relationship between amygdala activation and gaze-orienting behavior, functional magnetic resonance imaging data and eye movements were simultaneously acquired in the current study during the evaluation of facial expressions. Fearful, angry, happy, and neutral faces were briefly presented to healthy volunteers in an event-related manner. We controlled for the initial fixation by unpredictably shifting the faces downward or upward on each trial, such that the eyes or the mouth were presented at fixation. Across emotional expressions, participants showed a bias to shift their gaze toward the eyes, but the magnitude of this effect followed the distribution of diagnostically relevant regions in the face. Amygdala activity was specifically enhanced for fearful faces with the mouth aligned to fixation, and this differential activation predicted gazing behavior preferentially targeting the eye region. These results reveal a direct role of the amygdala in reflexive gaze initiation toward fearfully widened eyes. They mirror deficits observed in patients with amygdala lesions and open a window for future studies on patients with autism spectrum disorder, in which deficits in emotion recognition, probably related to atypical gaze patterns and abnormal amygdala activation, have been observed.

Oxytocin and Reduction of Social Threat Hypersensitivity in Women With Borderline Personality Disorder

Abstract: Objective: Patients with borderline personality disorder are characterized by emotional hyperarousal with increased stress levels, anger proneness, and hostile, impulsive behaviors. They tend to ascribe anger to ambiguous facial expressions and exhibit enhanced and prolonged reactions in response to threatening social cues, associated with enhanced and prolonged amygdala responses. Because the intranasal administration of the neuropeptide oxytocin has been shown to improve facial recognition and to shift attention away from negative social information, the authors investigated whether borderline patients would benefit from oxytocin administration. Method: In a randomized placebocontrolled double-blind group design, 40 nonmedicated, adult female patients with a current DSM-IV diagnosis of borderline personality disorder (two patients were excluded based on hormonal analyses) and 41 healthy women, matched on age, education, and IQ, took part in an emotion classification task 45 minutes after intranasal administration of 26 IU of oxytocin or placebo. Dependent variables were latencies and number or initial reflexive eye movements measured by eye tracking, manual response latencies, and blood-oxygen-level-dependent responses of theamygdalato angryandfearfulcompared with happy facial expressions. Results: Borderline patients exhibited more and faster initial fixation changes to the eyes of angry faces combined with increased amygdala activation in response to angry faces compared with the control group. These abnormal behavioral and neural patterns were normalized after oxytocin administration. Conclusions: Borderline patients exhibit a hypersensitivity to social threat in early, reflexive stages of information processing. Oxytocin may decrease social threat hypersensitivity and thus reduce anger and aggressive behavior in borderline personality disorder or other psychiatric disorders with enhanced threat-driven reactive aggression. (Am J Psychiatry 2013; 170:1169–1177)

Are you looking at me? Measuring the cone of gaze.

Abstract: The processing of gaze cues plays an important role in social interactions, and mutual gaze in particular is relevant for natural as well as video-mediated communications. Mutual gaze occurs when an observer looks at or in the direction of the eyes of another person. The authors chose the metaphor of a cone of gaze to characterize this range of gaze directions that constitutes "looking at" another person. In 4 experiments using either a real person or a virtual head, the authors investigated the influences of observer distance, head orientation, visibility of the eyes, and the presence of a 2nd head on the perceived direction and width of the gaze cone. The direction of the gaze cone was largely affected by all experimental manipulations, whereas its angular width remained comparatively stable.

Oxytocin and vasopressin in the human brain: social neuropeptides for translational medicine

Abstract: The neuropeptides oxytocin (OXT) and arginine vasopressin (AVP) are evolutionarily highly conserved mediators in the regulation of complex social cognition and behaviour. Recent studies have investigated the effects of OXT and AVP on human social interaction, the genetic mechanisms of inter-individual variation in social neuropeptide signalling and the actions of OXT and AVP in the human brain as revealed by neuroimaging. These data have advanced our understanding of the mechanisms by which these neuropeptides contribute to human social behaviour. OXT and AVP are emerging as targets for novel treatment approaches — particularly in synergistic combination with psychotherapy — for mental disorders characterized by social dysfunction, such as autism, social anxiety disorder, borderline personality disorder and schizophrenia.

Biological studies of post-traumatic stress disorder

Abstract: Post-traumatic stress disorder (PTSD) is the only major mental disorder for which a cause is considered to be known: that is, an event that involves threat to the physical integrity of oneself or others and induces a response of intense fear, helplessness or horror. Although PTSD is still largely regarded as a psychological phenomenon, over the past three decades the growth of the biological PTSD literature has been explosive, and thousands of references now exist. Ultimately, the impact of an environmental event, such as a psychological trauma, must be understood at organic, cellular and molecular levels. This Review attempts to present the current state of this understanding on the basis of psychophysiological, structural and functional neuroimaging, and endocrinological, genetic and molecular biological studies in humans and in animal models.

Toward a second-person neuroscience.

Abstract: In spite of the remarkable progress made in the burgeoning field of social neuroscience, the neural mechanisms that underlie social encounters are only beginning to be studied and could-paradoxically-be seen as representing the "dark matter" of social neuroscience. Recent conceptual and empirical developments consistently indicate the need for investigations that allow the study of real-time social encounters in a truly interactive manner. This suggestion is based on the premise that social cognition is fundamentally different when we are in interaction with others rather than merely observing them. In this article, we outline the theoretical conception of a second-person approach to other minds and review evidence from neuroimaging, psychophysiological studies, and related fields to argue for the development of a second-person neuroscience, which will help neuroscience to really "go social"; this may also be relevant for our understanding of psychiatric disorders construed as disorders of social cognition.