INTRODUCTION: Altered subjective visual sensitivity manifests as feelings of discomfort or overload elicited by intense and irritative visual stimuli. This can result in a host of visual aberrations including visual distortions, elementary visual hallucinations and visceral responses like dizziness and nausea, collectively referred to as "pattern glare." Current knowledge of the underlying neural mechanisms has focused on overall excitability of the visual cortex, but the individual contribution of excitatory and inhibitory systems has not yet been quantified. METHODS: In this study, we focus on the role of glutamate and γ-aminobutyric acid (GABA) as potential mediators of individual differences in subjective visual sensitivity, measured by a computerized Pattern Glare Test-a series of monochromatic square-wave gratings with three different spatial frequencies, while controlling for psychological variables related to sensory sensitivity with multiple questionnaires. Resting neurotransmitter concentrations in primary visual cortex (V1) and right anterior insula were studied in 160 healthy participants using magnetic resonance spectroscopy. RESULTS: Data showed significant differences in the perception of visual distortions (VD) and comfort scores between men and women, with women generally reporting more VD, and therefore the modulatory effect of sex was considered in a further examination. A general linear model analysis showed a negative effect of occipital glutamate on a number of reported visual distortions, but also a significant role of several background psychological traits. When assessing comfort scores in women, an important intervening variable was the menstrual cycle. DISCUSSION: Our findings do not support that baseline neurotransmitter levels have a significant role in overreactivity to aversive stimuli in neurotypical population. However, we demonstrated that biological sex can have a significant impact on subjective responses. Based on this additional finding, we suggest that future studies investigate aversive visual stimuli while examining the role of biological sex.

• Publikační typ
• časopisecké články MeSH

The article introduces an original VR-based experiment which explores context-dependent memory recall in humans. It specifically examines the recall of correct and falsely induced semantic memories. With the aid of VR head-mounted displays, 92 students of psychology were placed in a computer-generated indoor virtual environment and asked to memorize the presented lists of words. Afterwards, the participants were placed in the same indoor virtual environment or an alternative outdoor virtual environment and asked to recall the words. The number of correct and falsely induced words was then measured. On average, women recalled significantly more correct words from the list than men, regardless of the environmental context. Despite the assumptions, we did not observe a separate effect of exposure to different environments during learning and recall of material on memory performance. Likewise, we did not detect any effects of the learning context or biological sex in the case of the production of false memories. These results provide a novel insight into previous knowledge regarding the memory processes that occur in virtual environments. Although we failed to confirm the role of context in recalling learned material in general, we found a hint that this context might interact with specific memory processes of biological sexes. However, the design of this study only captured the effect of changing the environment during memory recall and did not address the role of specific context in remembering learning material. Further research is therefore needed to better investigate these phenomena and examine the role of biological sex in context-dependent memory processes.

• MeSH
• kognice MeSH
• lidé MeSH
• paměť * MeSH
• represe (psychologie) MeSH
• rozpomínání MeSH
• učení * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Mental imagery related to the recent death of a loved one is associated with intense sadness and distress. Social relations, such as with one's significant other, can regulate negative emotions and provide comfort, but the neural correlates of social comfort are largely unknown. In this functional magnetic resonance imaging study, we examined brain responses to sad mental imagery and how these are modulated by holding hands with one's romantic partner. We found that mental imagery of a recently deceased loved one was associated with increased reactivity in the dorsal striatum, medial prefrontal cortex, anterior and posterior cingulate cortex, thalamus and cerebellum. Holding hands with one's partner as compared to being alone or holding hands with a stranger provided subjective comfort and reduced neural reactivity in the dorsal striatum without affecting the vividness of the imagery. Our findings indicate an important role for the dorsal striatum in sad mental imagery and social comfort and suggest that tactile social support by one's romantic partner regulates subjective distress through other processes than mere distraction from the mental imagery.

• MeSH
• cingulární gyrus diagnostické zobrazování   fyziologie   MeSH
• dospělí MeSH
• hmatová percepce fyziologie   MeSH
• imaginace fyziologie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mladý dospělý MeSH
• mozeček diagnostické zobrazování   fyziologie   MeSH
• neostriatum diagnostické zobrazování   fyziologie   MeSH
• prefrontální mozková kůra diagnostické zobrazování   fyziologie   MeSH
• připoutání k objektu * MeSH
• sexuální partneři MeSH
• smutek fyziologie   MeSH
• sociální opora * MeSH
• thalamus diagnostické zobrazování   fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Social touch may modulate emotions, but the neurobehavioral correlates are poorly understood. Here, we investigated neural responses to a picture of a deceased close person and if neural activity and connectivity are modulated by social touch from one's romantic partner. Using functional magnetic resonance imaging, we found altered reactivity in several brain areas including the anterior cingulate cortex (ACC) and the anterior insula in response to the personal picture compared to a picture of an unfamiliar person. Hand holding with the romantic partner, compared to being alone, reduced reactivity in the ACC and cerebellum and provided subjective comfort. To separate physical touch from the emotional effect of partner presence, we evaluated hand holding with the partner relative to a stranger and found reduced reactivity in the anterior insula. Connectivity between the anterior insula and the ACC was reduced during partner touch, and the connectivity strength was negatively related to attachment security, with higher reported partner security associated with weaker connectivity. Overall, holding hands with one's partner attenuates reactivity in emotional brain areas and reduces between-region connectivity.

• MeSH
• cingulární gyrus fyziologie   MeSH
• dospělí MeSH
• emoce fyziologie   MeSH
• hmat MeSH
• hmatová percepce fyziologie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mapování mozku metody   MeSH
• mozek fyziologie   MeSH
• mozková kůra fyziologie   MeSH
• sexuální partneři psychologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH