Sebastian Ocklenburg

MSH Medical School Hamburg – University of Applied Sciences and Medical University | MSH · Department of Psychology

Structural hemispheric asymmetry has long been assumed to guide functional lateralization of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional lateralization than macrostructural asymmetries. To investigate the li...

Athletes in bodybuilding can pose favouring one side or the other of the body while being evaluated in the contests. While previous research assessed lateral bias of posing in a variety of situations, no investigation has been conducted in bodybuilding. We analyzed the lateral posing bias of the Top 15 athletes for the mandatory poses in Classic Ph...

Borderline personality disorder (BPD) is characterized by increased mood reactivity and affective instability. Since core structures involved in emotion processing, such as the amygdala, demonstrate strong lateralization, BPD is an interesting target for laterality research. So far, a systematic integration of findings on lateralization in BPD is m...

How stress affects functional hemispheric asymmetries is relevant because stress represents a risk factor for the development of mental disorders and various mental disorders are associated with atypical lateralization. Using three lateralization tasks, we investigated whether functional hemispheric asymmetries in the form of hemispheric dominance...

Several neurodevelopmental disorders are associated with a higher prevalence of atypical laterality (e.g., left-handedness). Both genetic and non-genetic factors play a role in this association, yet the underlying neurobiological mechanisms are largely unclear. Recent studies have found that stress, mediated by the hypothalamic-pituitary–adrenal (H...

The traditional classifications of motor skills nature (open vs closed; fine vs gross) have not been considered in handedness investigations. Instead, previous research focused on comparing complex vs less complex motor behaviour, leaving a gap in the literature. We compared manual preference between different motor skill characteristics, namely: f...

Structural hemispheric asymmetry has long been assumed to guide functional asymmetry of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional asymmetries than macrostructural asymmetries. To investigate the link betwe...

Structural hemispheric asymmetry has long been assumed to guide functional asymmetry of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional asymmetries than macrostructural asymmetries. To investigate the link betwe...

Human-induced climate change has led to an increased likelihood of several types of natural disasters in recent years, including wildfires and floods. These are often acutely life-threatening and traumatic for the people affected, leading to an increased prevalence of post-traumatic stress disorders and other mental illnesses.

The healthcare system in Germany is not prepared for the additional strain caused by the climate crisis. Urgent political decisions are needed to equip our healthcare provision for climate-related damages. We have an important role to play, not only in supporting patients and clients, but also in shaping this process.

The brain of a species has evolved over evolutionary time periods to adapt to the ecological niche that this species occupies. Due to the climate crisis, many ecological niches are changing rapidly and some are disappearing entirely. Species whose brains are strongly adapted to a specific ecological niche will therefore likely struggle more with th...

The structure and function of the brain can change throughout life due to training processes and environmental influences. Environmental neuroscience deals with the processes by which the environment influences the brain. As the climate crisis is associated with massive changes in the environment, environmental neuroscience research is essential to...

At the Paris Climate Agreement, the majority of the world agreed to limit global warming to 1.5 °C. Today, we are already at 1.1 °C and the probability of staying below 1.5 °C is considered by scientists to be vanishingly small. The reason for this is the lack of political implementation of climate protection measures and the increasingly likely re...

Human-induced climate change will be one of the most significant influences on the human psyche over the coming decades. It is therefore of central importance to further expand psychological and neuroscientific research on the effects of climate change on brain function and mental health.

We are not only in a climate crisis, but also in a biodiversity crisis closely linked to it. Many animal and plant species are threatened with extinction and more and more ecosystems are being destroyed by humans. Studies show that spending time in nature is beneficial for our mental health. Moreover, witnessing the destruction of the environment t...

Temperature affects our mental well-being, and extremely cold or hot temperatures can lead to dissatisfaction. Research findings indicate that increasing heat will negatively impact our mental health. It will lead to reduced sleep quality, more fatigue, fewer social contacts, and potentially increased suicidality in some regions of the world. Indiv...

While most people are right-handed, a minority are left-handed or mixed-handed. It has been suggested that mental and developmental disorders are associated with increased prevalence of left-handedness and mixed-handedness. However, substantial heterogeneity exists across disorders, indicating that not all disorders are associated with a considerab...

The widespread prevalence of brain asymmetries in animals and humans indicates that there is an evolutionary pressure towards an asymmetric organization of nervous systems. Therefore, this chapter explains various approaches to the evolution of left-handedness and brain asymmetries.

For a long time, it was assumed that left-handedness is a typically human phenomenon and animals do not show comparable preferences. This assumption is fundamentally wrong. Current studies show that paw preference and similar phenomena occur in all major groups of animals. Therefore, brain asymmetries represent a fundamental principle of brain orga...

Left-handedness and brain asymmetries are influenced by a variety of genetic and environmental factors. Interestingly, left-handedness is determined in many people even before birth, which suggests an important role of early developmental factors.

A number of studies have investigated whether left-handed people have an advantage in various sports. It was found that this is indeed the case in various martial arts and ball sports. This is probably because left-handed people have an element of surprise on their side in sports.

Not every person retains their innate handedness until the end of their life. Sometimes, due to an injury to the hand or the amputation of an arm, it may be necessary to relearn handedness. In addition, there is also forced relearning by parents or school staff. This chapter therefore deals with the effects of such relearning of handedness.

Are left-handed people actually more intelligent and creative than right-handed people? While some older studies with small sample sizes reported such correlations, newer and larger studies have shown that there are no substantial differences in intelligence between left-handed and right-handed people. The data situation regarding creativity is sti...

Left-handedness is a form of so-called brain asymmetries, that is, functional differences between the right and left halves of the brain. Beyond handedness, there are many other forms of brain asymmetries, such as in language or the processing of faces or emotions.

Many, but not all, mental disorders and developmental disorders are associated with an increased rate of left-handedness and mixed-handedness, as well as an increased rate of hemispheric asymmetries with atypical direction. An explanation for this pattern could be that genes and environmental factors influencing brain development affect both handed...

In determining left-handedness, a distinction is made between the subjectively perceived hand preference and the objectively measured hand skill.

No two human brains are alike, and with the rise of precision medicine in neurology, we are seeing an increased emphasis on understanding the individual variability in brain structure and function that renders every brain unique. Functional and structural brain asymmetries are a fundamental principle of brain organization, and recent research sugge...

The human brain shows distinct lateralized activation patterns for a range of cognitive processes. One such function, which is thought to be lateralized to the right hemisphere (RH), is human face processing. Its importance for social communication and interaction has led to a plethora of studies investigating face processing in health and disease....

An increased prevalence of mixed-handedness has been reported in several neurodevelopmental and psychiatric disorders. Unfortunately, there is high between-study variability in the definition of mixed-handedness, leading to a major methodological problem in clinical laterality research and endangering replicability and comparability of research fin...

Hugs are a form of social touch that serve to allow people to interact in social situations and communicate emotions. On the hormonal side, they increase the release of the bonding hormone oxytocin.

Humans are not the only organisms that hug. Especially in great apes and other monkey species, there is convincing evidence for a wide distribution of hugs. Evolutionary advantages of hugging include social thermoregulation, comforting after conflicts, and stress reduction.

Hugs can help to reduce stress, and stress affects the immune system and the risk of various physical illnesses. Therefore, various studies have investigated the extent to which hugs affect physical health. It was found that hugs have a positive effect on the risk of catching a cold, various risk factors for cardiovascular diseases, and self-percei...

What determines who we hug and who we do not hug? Besides the emotional closeness to the other person, our cultural background is a decisive factor. Here it was shown that people in warmer countries hug more than people in colder countries. People in more religious countries, on the other hand, hug less than people in less religious countries. In a...

The study of the hug is a young field in psychological and neuroscientific research. Therefore, there are still many unanswered questions that should be explored in future studies.

Hugs are a complex, multidimensional behavior that can be characterized by a whole range of aspects. These include the number of people hugging, the duration of the hug, the movements of individual body parts, the strength of the squeeze, the side of the hug, the emotional significance of the situation, as well as the relationships, personalities,...

Many people, especially during stressful periods of life, feel the desire to be hugged. Various studies have shown that hugs can help regulate stress. Both hugs from others and self-hugs lead to a reduction in the stress hormone cortisol.

Background Bipolar disorder (BD) is often seen as a bridge between schizophrenia and depression in terms of symptomatology and etiology. Interestingly, hemispheric asymmetries as well as behavioral lateralization are shifted towards a tendency of left-side or mixed-side bias in schizophrenia whereas no shift is observed in subjects with depression....

Touching a mark on the own body when seeing this mark in a mirror is regarded as a correlate of self-awareness and seems confined to great apes and a few further species. However, this paradigm often produces false-negative results and possibly dichotomizes a gradual evolutionary transition of self-recognition. We hypothesized that this ability is...

Reduced hemispheric asymmetries, as well as their behavioral manifestation in the form of atypical handedness (i.e., non-right, left-, or mixed-handedness), are linked to neurodevelopmental disorders, such as autism spectrum disorder, and several psychiatric disorders, such as schizophrenia. One neurodevelopmental disorder that is associated with r...

The development of handedness and other form of functional asymmetries is not yet understood in its critical determinants. Early life factors (e.g., birth weight, birth order) have been discussed to contribute to individual manifestations of functional asymmetries. However, large-scale data such as the UK Biobank suggest that the variance in handed...

Handedness is a core phenotype in clinical laterality research and several different disorders such as schizophrenia and autism spectrum disorders have been linked to a higher prevalence of non-right-handedness. Moreover, subclinical personality traits like schizotypy have been linked to a higher prevalence of non-right-handedness. The association...

Since almost a hundred years, psychologists have investigated the link between hand preference and dyslexia. We present a meta-analysis to determine whether there is indeed an increase in atypical hand preference in dyslexia. We included studies used in two previous meta-analyses (Bishop, 1990; Eglinton & Annett, 1994) as well as studies identified...

Virtual reality (VR) is increasingly used in neuroscientific research to increase ecological validity without sacrificing experimental control, to provide a richer visual and multisensory experience, and to foster immersion and presence in study participants, which leads to increased motivation and affective experience. But the use of VR, particula...

Most studies on emotion processing induce emotions through images or films. However, this method lacks ecological validity, limiting generalization to real-life emotion processing. More realistic paradigms using virtual reality (VR) may be better suited to investigate authentic emotional states and their neuronal correlates. This pre-registered stu...

The amygdala is an evolutionarily conserved core structure in emotion processing and one of the key regions of interest in affective neuroscience. Results of neuroimaging studies focusing on the amygdala are, however, often heterogeneous since it is composed of functionally and neuroanatomically distinct subnuclei. Fortunately, ultra-high-field ima...

Hemispheric asymmetries differ considerably across species, but the neurophysiological base of this variation is unclear. It has been suggested that hemispheric asymmetries evolved to bypass interhemispheric conduction delay when performing time-critical tasks. This implies that large brains should be more asymmetric. We performed preregistered cro...

Stress exposure and reactivity may show differential associations with handedness, but shallow phenotyping may influence the current knowledge. Importantly, different handedness measures do not necessarily show high correlations with each other and should not be used interchangeably as they may reflect different dimensions of laterality. Here, data...

Stress has been suggested as a factor that may explain the link between altered functional lateralization and psychopathology. Modulation of the function of the corpus callosum via stress hormones may be crucial in this regard. Interestingly, there is evidence that interhemispheric integration and hemispheric asymmetries are modifiable by endocrino...

The COVID-19 pandemic has necessitated a drastic decrease in human social interactions including social touch. One of the most prevalent forms of touch is hugging. Hugging has been demonstrated to benefit both physical and mental well-being. In the present study, we used an ecological momentary assessment approach to assess the relationship between...

Intelligence is highly heritable. Genome-wide association studies (GWAS) have shown that thousands of alleles contribute to variation in intelligence with small effect sizes. Polygenic scores (PGS), which combine these effects into one genetic summary measure, are increasingly used to investigate polygenic effects in independent samples. Whereas PG...

Dogs are one of the key animal species in investigating the biological mechanisms of behavioral laterality. Cerebral asymmetries are assumed to be influenced by stress, but this subject has not yet been studied in dogs. This study aims to investigate the effect of stress on laterality in dogs by using two different motor laterality tests: the Kong™...

The brain is built with hemispheric asymmetries in structure and function to enable fast neuronal processing. In neuroimaging studies, several mental disorders have been associated with altered or attenuated hemispheric asymmetries. However, the exact mechanism linking asymmetries and disorders is not known. Here, studies in animal models of mental...

Was bestimmt, wen wir umarmen und wen nicht? Neben der emotionalen Nähe zu der anderen Person ist unser kultureller Hintergrund ein entscheidender Faktor. Hier zeigte sich, dass Menschen in wärmeren Ländern mehr umarmen als Menschen in kälteren Ländern. Menschen in religiöseren Ländern umarmen hingegen weniger als Menschen in weniger religiösen Län...

Umarmungen sind ein komplexes, multidimensionales Verhalten, das durch eine ganze Reihe von Aspekten charakterisiert werden kann. Dazu zählen die Anzahl der sich umarmenden Menschen, die Dauer der Umarmung, die Bewegungen einzelner Körperteile, der Stärke des Drückens, die Seite der Umarmung, die emotionale Bedeutung der Situation sowie die Beziehu...

Umarmungen sind eine Form sozialer Berührungen, die dazu dienen, dass Menschen sich in sozialen Situationen austauschen und Emotionen kommunizieren. Auf der hormonellen Seite erhöhen sie die Ausschüttung des Bindungshormons Oxytocin.

Viele Menschen haben besonders in stressigen Lebensabschnitten das Gefühl, dass sie gerne mal in den Arm genommen werden möchten. Verschiedene Studien konnten zeigen, dass Umarmungen helfen können, Stress zu regulieren. So führen sowohl Umarmungen durch andere Menschen als auch Selbstumarmungen zu einer Reduktion des Stresshormons Cortisol.

Die Erforschung der Umarmung ist ein junges Feld in der psychologischen und neurowissenschaftlichen Forschung. Daher gibt es noch viele ungeklärte Fragen, die in zukünftigen Studien erforscht werden sollten.

Menschen sind nicht die einzigen Organismen, die umarmen. Grade bei Menschenaffen und anderen Affenarten gibt es überzeugende Belege für eine weite Verbreitung von Umarmungen. Evolutionäre Vorteile von Umarmungen beinhalten soziale Thermoregulation, das Trösten nach Konflikten und die Reduktion von Stress.

Umarmungen können helfen, Stress zu reduzieren und Stress wirkt sich auf das Immunsystem und das Risiko verschiedener körperlichen Erkrankungen aus. Daher wurde in verschiedenen Studien untersucht, inwiefern sich Umarmungen auf die körperliche Gesundheit auswirken. Es zeigte sich, dass Umarmungen einen positiven Effekt auf das Erkältungsrisiko, ver...

Hemispheric asymmetries differ considerably across species, but the neurophysiological base of this variation is unclear. It has been suggested that hemispheric asymmetries evolved to bypass interhemispheric conduction delay when performing time critical tasks. This implies that large brains should be more asymmetric. We performed preregistered cro...

Structural hemispheric asymmetry has long been assumed to guide functional asymmetry of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional asymmetries than macrostructural asymmetries. To investigate the link betwe...

Structural hemispheric asymmetry has long been assumed to guide functional lateralization of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional lateralization than macrostructural asymmetries. To investigate the li...

The main objective of this meta-analysis was to investigate handedness in post-traumatic stress disorder on a meta-analytical level. For this purpose, articles were identified via a search in PubMed, PsychInfo, PubPsych, ResearchGate, and Google Scholar. Studies reporting findings relating to handedness in PTSD patients and healthy controls were co...

Reduced hemispheric asymmetries, as well as their behavioral manifestation in the form of atypical handedness (i.e., non-right, left-, or mixed-handedness), are linked to neurodevelopmental disorders, such as autism spectrum disorder, attention deficit hyperactivity disorder, and several psychiatric disorders. One neurodevelopmental disorder that i...

A single chronic stress is often considered a potential reinforcer in psychiatric disorders. Lithium and ketamine both seem to ameliorate the consequences of stress. Here, male mice were either injected with lithium carbonate (LiCl), ketamine hydrochloride (KET), or sodium chloride (NaCl; controls) over nine consecutive days. Treatment was followed...