Biology subjects

Klamer, K.

Publications and source records attributed to Klamer, K..

4 recordsLinked to original sources

bioRxiv2024

Lower perceived stress enhances neural synchrony in perceptual and attentional cortices during naturalistic processing

Perceived stress is the subjective appraisal of the level of stress experienced by an individual in response to external or internal demands. Recent research on perceived stress has highlighted its role in influencing cognition, leading to a disruption in cognitive processes, such as emotional processing, attention, and perception. However, most neuroimaging studies examining stress have used static stimuli (e.g., still images) that do not encapsulate real-life multimodal processing in the brain. The current research uses data from the Naturalistic Neuroimaging Database (v2.0; Aliko et al., 2020) to examine differences in neural synchrony (as measured by intersubject correlations; ISCs) associated with perceived stress using functional magnetic resonance imaging (fMRI). We evaluated how self-reported perceived stress levels influence neural synchrony patterns in response to different naturalistic stimuli by examining the differences in neural synchrony between individuals with low and high perceived stress levels. We determined that lower perceived stress was observed with greater neural synchrony areas associated with perceptual and attention processing, including the lateral occipital cortex, superior temporal gyrus, superior parietal lobule, orbital frontal cortex, and the occipital pole. These results indicate that high levels of perceived stress heavily alter neural processing of complex audiovisual stimuli. Together, these results provide evidence that perceived stress influences cognitive processing in everyday life.

neuroscience↗

bioRxiv2023

Psychological well-being modulates neural synchrony during naturalistic fMRI

Psychological well-being (PWB) is a combination of self-acceptance, life purpose, personal growth, positive relationships, and autonomy, and has a significant relationship with physical and mental health. Previous studies using resting-state functional magnetic resonance imaging (fMRI) and static picture stimuli have implicated the anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), orbitofrontal cortex (OFC), insula and thalamus in PWB, however, the replication of associations across studies is scarce, both in strength and direction, resulting in the absence of a model of how PWB impacts neurological processing. Naturalistic stimuli better encapsulate everyday experiences and can elicit more "true-to-life" neurological responses, and therefore may be a more appropriate tool to study PWB. The current study seeks to identify how differing levels of PWB modulate neural synchrony in response to an audiovisual film. With consideration of the inherent variability of the literature, we aim to ascertain the validity of the regions previously mentioned and their association with PWB. We identified that higher levels of PWB were associated with heightened neural synchrony in the bilateral OFC and left PCC, and that lower levels of PWB were associated with heightened neural synchrony in the right temporal parietal junction (TPJ) and left superior parietal lobule (SPL), regions related to narrative processing. Taken together, this research confirms the validity of several regions in association with PWB and suggests that varying levels of PWB produce differences in the processing of a narrative during complex audiovisual processing.

neuroscience↗

bioRxiv2023

Trait level somatic arousal modulates fMRI neural synchrony to naturalistic stimuli

Somatic arousal refers to the physiological and bodily responses that occur in reaction to different emotional and psychological stimuli and is a crucial component of the fight or flight response. Symptoms associated with higher levels of somatic arousal such as higher heart and respiration rates have been shown to impact the blood oxygenation level dependent (BOLD) signal during functional magnetic resonance imaging (fMRI) studies. Differences in baseline levels of somatic arousal may therefore modulate the brains response to incoming stimuli during fMRI. Previous studies typically investigate somatic arousal as a state, rather than as a trait, in which some individuals are more likely to have heightened physiological responses to psychological stimuli, causing the neurological mechanisms behind baseline somatic arousal levels to remain poorly understood. The current study seeks to identify how differing levels of baseline somatic arousal modulate neural synchrony in response to an audiovisual film. We hypothesize that individuals with higher levels of somatic arousal will show overall heightened neural synchrony in response to a complex audiovisual stimulus. We identified that higher levels of somatic arousal are associated with widespread neural synchrony across the brain, including frontal gyri, parietal and temporo-occipital cortices. Taken together, this research suggests that baseline somatic arousal levels should be measured during naturalistic fMRI paradigms, as baseline somatic arousal levels may have a profound influence on synchronous neural activity.

neuroscience↗

bioRxiv2023

Mapping the Changing Neural Architecture of Narrative Processing Using Naturalistic Stimuli: an fMRI Study

A narrative is a coherent representation of actual or fictional events designed to connect experiences. Narratives provide a unique opportunity to investigate brain functions in scenarios more closely resembling real-world experiences. However, most neuroimaging studies examining narrative formation have utilized static stimuli that fail to capture the intricacies of narrative construction in everyday life, particularly how cognitive demands change over the course of narrative processing. The current research uses functional magnetic resonance imaging (fMRI) to examine dynamic narrative processing over the course of a full-length audiovisual narrative. We examined changes in neural synchrony (as quantified by intersubject correlations) in areas related to semantic memory, episodic memory, and visuospatial attention between the beginning, middle, and end of the narrative. Results from two experiments identified two core narrative processing networks responsible for constructing coherent representations across extended timescales. The first network is associated with the early narrative construction, and includes the right intraparietal sulcus/superior parietal lobule, bilateral angular gyrus, bilateral precuneus, and left fusiform gyrus. The second network consists of the right ventral frontal cortex and bilateral parahippocampal cortices, and is associated with longer term narrative integration. Together, these regions provide the framework for successful narrative processing during naturalistic stimuli.

neuroscience↗