Benjamin ClemensRWTH Aachen University · Department of Psychiatry, Psychotherapy and Psychosomatics
Benjamin Clemens
Dr. rer. medic.
About
32
Publications
14,068
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518
Citations
Citations since 2017
Introduction
Additional affiliations
January 2011 - present
Rheinisch-Westfälische Technische Hochschule Aachen
Education
September 2008 - February 2012
Publications
Publications (32)
The exact neurobiological underpinnings of gender identity (i.e., the subjective perception of oneself belonging to a certain gender) still remain unknown. Combining both resting-state functional connectivity and behavioral data, we examined gender identity in cisgender and transgender persons using a data-driven machine learning strategy. Intrinsi...
Aggression affects nearly all mental disorders and constitutes a burden for society in general and the mental health sector in particular. An incomplete understanding of its underlying neurobiological mechanisms limits treatment efficacy and hinders the development of precision medicine approaches. Here we review recent efforts employing neuroimagi...
The failure to adequately regulate negative emotions represents a prominent characteristic of violent offenders. In this functional magnetic resonance imaging study, we used technical, nonsocial frustration to elicit anger in violent offenders (n = 19) and then increased the provocation by adding personal insults (social provocation). The aim was t...
Background:
Sexual orientation in humans represents a multilevel construct that is grounded in both neurobiological and environmental factors.
Objective:
Here, we bring to bear a machine learning approach to predict sexual orientation from gray matter volumes (GMVs) or resting-state functional connectivity (RSFC) in a cohort of 45 heterosexual a...
The increasing use of machine learning approaches on neuroimaging data comes with the important concern of confounding variables which might lead to biased predictions and in turn spurious conclusions about the relationship between the features and the target. A prominent example is the brain size difference between women and men. This difference i...
We study the statistical properties of facial behaviour altered by the regulation of brain arousal in the clinical domain of psychiatry. The underlying mechanism is linked to the empirical interpretation of the vigilance continuum as behavioral surrogate measurement for certain states of mind. Referring to the classical scalp-based obtrusive measur...
Brain size differs substantially between human males and females. This difference in total intracranial volume (TIV) can cause bias when employing machine-learning approaches for the investigation of sex differences in brain morphology. TIV-biased models will likely not capture actual qualitative sex differences in brain organization but rather lea...
This paper represents the outcome of a multidisciplinary discussion on what works, what does not, and what can be improved, in ongoing work on biobehavioral taxonomies and their biomarkers. The authors of this paper, representing a wide spectrum of biobehavioral disciplines (clinical, developmental, differential psychology, neurophysiology, endocri...
The brain structural changes related to gender incongruence (GI) are still poorly understood. Previous studies comparing gray matter volumes (GMV) between cisgender and transgender individuals with GI revealed conflicting results. Leveraging a comprehensive sample of transmen (n = 33), transwomen (n = 33), cismen (n = 24), and ciswomen (n = 25), we...
Increased aggression and impulsivity represent a key component of several psychiatric disorders, including substance use disorder, which is often associated with deficient prefrontal brain activation. Thus, innovative tools to increase cognitive control are highly warranted.
The current study investigates the potential of transcranial direct curren...
Aggression and psychopathy are multifaceted conditions determined interpersonal and antisocial factors. Only a few studies analyze the link between these separate factors and specific brain morphology distinctively. A voxel-based morphometry (VBM) analysis was performed on 27 violent offenders and 27 controls aiming to associate sub-features of agg...
Current models of aggression suggest that in addition to personality traits and environmental factors, biological vulnerability associated with genetics substantially impacts aggressive behavior. In a functional imaging study, we investigated the influence of the single nucleotide polymorphism of the mu 1 subtype opioid receptor gene (OPRM1), impli...
Using a combined approach of fMRI and non-invasive brain stimulation (tDCS), the present study investigated source memory and its link to mental imagery in the olfactory domain, as well as in the auditory domain. Source memory refers to the knowledge of the origin of mental experiences, differentiating events that have occurred and memories of imag...
Animal studies suggest a causal link between testosterone and aggression. However, in human research the exact role of this hormone is still unclear, having been linked to dominance and approach behavior rather than to aggression per se. In a social context, the induction of aggression might be confounded with dominance or status changes, which pot...
Testosterone, a male sex hormone, has been suggested to partly explain mixed findings in males and females when investigating behavioral tendencies associated with the MAOA polymorphism. Prior studies indicated that the MAOA polymorphism represents a vulnerability factor for financial risk-taking and harm avoidance and that testosterone increases h...
Social stress has a major detrimental impact on subjective well-being. Previous research mainly focused on two methods to induce and measure social stress: social exclusion and performance evaluation. For social exclusion researchers frequently focused on the Cyberball task, which in contrast to many psychosocial stress paradigms does not include a...
Introduction
Recent research found gender‐related differences in resting‐state functional connectivity (rs‐FC) measured by functional magnetic resonance imaging (fMRI). To the best of our knowledge, there are no studies examining the differences in rs‐FC between men, women, and individuals who report a discrepancy between their anatomical sex and t...
Stress affects the brain at a network level: the salience network is supposedly upregulated, while at the same time the executive control network is downregulated. While theoretically described, the effects in the aftermath of stress have thus far not been tested empirically. Here, we compared for the first time resting-state functional connectivit...
Approximately 73% of patients suffering from Borderline personality disorder (BPD) exhibit aggressive behaviour, which severely hinders therapeutic work and clinical improvement. Because the underlying mechanisms of aggression in BPD are not yet completely understood , additional research in this domain has a high clinical and scientific relevance....
Up to now it remains unclear how stress in a social context affects the resting human brain, as assessed by functional magnetic resonance imaging (fMRI). Here, we compared for the first time resting-state functional connectivity in a large sample of healthy volunteers before and after the cyberball task. Of primary interest were the salience restin...
In the clinical practice, particularly during therapy
sessions with psychiatric patients, heightened
aggression constitutes a dangerous and detrimental
situation for both clinicians and patients
according to many experts. The primary reason
for the lack of efficient treatment options for pathological
aggression is an insufficient and incomplete
und...
Violence is a topic of great social relevance, frequently causing tremendous health consequences for those affected and high consequential costs for health care and the national economy. The established consulting and assistance services are usually restricted to offers for ambulant supply, mainly from private agencies or societies. As a result, th...
In functional magnetic resonance imaging (fMRI) studies that apply a “subsequent memory” approach, successful encoding is indicated by increased fMRI activity during the encoding phase for hits vs. misses, in areas underlying memory encoding such as the hippocampal formation. Signal-detection theory (SDT) can be used to analyze memory-related fMRI...
Background:
Violence has many faces and often results in a variety of consequences. Some studies indicated different types of violence and health consequences in men and women. However, it is still unclear whether this is reflected in clinical context, for example in a patient sample of a German university hospital.
Objectives:
The primary goal...
Although numerous studies examined resting-state networks (RSN) in the human brain, so far little is known about how activity within RSN might be modulated by non-invasive brain stimulation applied over parietal cortex. Investigating changes in RSN in response to parietal cortex stimulation might tell us more about how non-invasive techniques such...
Up to now, it remains unclear how monoamine oxidase A (MAOA), which has been repeatedly linked to aggression, affects brain activity within resting-state networks (RSN). Here, we used functional magnetic resonance imaging (fMRI) to test whether the MAOA genotype might influence activity within the common RSN. Our results demonstrate that during res...
Transcranial direct current stimulation (tDCS) is a non-invasive technique which has been used to modulate various cognitive functions in healthy participants as well as stroke patients. Despite the increasing number of tDCS studies, it still remains questionable whether tDCS is suitable for modulating performance in arithmetic tasks and whether a...
Purpose:
Behavioural studies of attention training after brain damage have shown that only training procedures specifically related to the impaired attention function lead to significant improvements in the respective attention domain when using psychometric tests addressing these functions. The main objective of this fMRI study was to investigate...
Mental imagery is a complex cognitive process that resembles the experience of perceiving an object when this object is not physically present to the senses. It has been shown that, depending on the sensory nature of the object, mental imagery also involves correspondent sensory neural mechanisms. However, it remains unclear which areas of the brai...
Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy p...
Questions
Question (1)
We are investigating the cortisol concentration before and after a stress-inducing task (Cyberball) and we’d like to know if there’s a problem if subjects have a dry mouth after the task (which we experience quite a few time with our subjects) or if the salivary flow is increased because of the task. We received a suggestion from a supposed expert, that the contribution of cortisol to saliva is continuous which may be a problem if there’s a different amount of saliva produced but the hormone contribution stays the same. This would mean that the concentration of cortisol is primarily influenced by the salivary flow and not by the actual release of stress induced cortisol.
Is this actually the case or not???
What we would need in this case is some kind of reference-values that can tell us how much saliva has been produced in a certain time.
Does anybody know if there is this salivary influence and do you have any suggestions for a reference or how to handle this problem?!
And does anybody know the influence of salivary flow on testosterone, too?
All suggestions are welcome!!! And in advance - thanks a lot for all answers!
