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Biology subjects

Seppälä, K.

Publications and source records attributed to Seppälä, K..

6 recordsLinked to original sources

Neural Representations of Embodied Musical Emotions

Bodily sensations shape the emotional experience of music, yet the neural underpinnings of embodied musical emotions remain poorly understood. Here we investigated the correspondence between neural activity patterns and self-reported bodily sensations induced by emotional music. Participants (n=74) listened to emotionally engaging (aggressive, happy, sad, scary) music while their hemodynamic brain activity was measured with functional magnetic resonance imaging (fMRI). Music-induced bodily sensations were measured after imaging. Representational similarity analysis (RSA) was used to identify brain regions where the representational geometries of neural responses to music align with the topographical patterns of the corresponding bodily sensations, emotions, and musical features. Bodily sensations maps (BSMs) showed emotion-specific topographies. Univariate general linear model (GLM) analysis revealed increased neural activity within motor, somatosensory, interoceptive, limbic, and auditory brain regions during music listening, with little difference between the emotion categories. In contrast, RSA revealed significant correspondence between the representational geometries of neural activity patterns and emotion category-specific bodily sensations in motor, somatosensory, emotion-related and auditory brain regions. Multivariate pattern (MVP) classification analysis showed that activity in the auditory cortex accurately predicted the emotion categories. Our results indicate neural correspondence to bodily sensations in somatomotor and somatosensory brain regions, providing novel evidence for the neural basis of embodied music-induced emotions.

neuroscience↗

Intraspecific genetic variation modulates immune responses to acute heat exposure in an aquatic ectotherm

Climate change-induced heatwaves threaten ectotherms, whose physiology is tightly coupled to ambient temperature. Vulnerability assessments often rely on data from one or a few populations, implicitly assuming uniform thermal sensitivity across species genetic diversity. Quantifying such variation is especially important for traits with wider ecological consequences; our focus here is on immune function, which shapes disease dynamics. We addressed this knowledge gap using ten clonal lineages of the New Zealand snail Potamopyrgus antipodarum exposed to ambient (17{degrees}C) or heatwave conditions (27{degrees}C) for 4 or 8 days. We measured two complementary innate immune traits: general phenoloxidase-like (PO-like) activity, which integrates the activity of multiple phenoloxidase enzymes, and laccase activity, which targets a specific PO enzyme subclass important in mollusc immunity. Heat exposure suppressed both traits, but patterns differed across clones. While PO-like activity declined uniformly, laccase activity showed substantial among-clone variation in heatwave responses at day 4, though these differences converged by day 8. Heat-induced immune suppression is thus trait-specific, depends on genetic background, and varies with exposure duration. Together, these results demonstrate that studies limited to a single genotype, population, or timepoint risk miscalculating species-level vulnerability.

physiology↗

Attentional reconfiguration during acute and sustained fear

BACKGROUNDFear is a fundamental survival mechanism that both enhances the chances of survival by rapid detection and adaptive responses to potential threat and by optimizing sensory input and cognitive processing. Here we used naturalistic design with eye tracking to map the spatiotemporal dynamics of attention and arousal during fearful events with slow and fast temporal dynamics. METHODS21 participants watched a full-length horror movie while their eye-movements were recoded with eye tracker. Moment-to-moment intensity of sustained fear as well as the onsets of the jump scares (acute fear) were annotated and used to predict gaze parameters (fixation duration & counts, blink frequency, saccade amplitude, pupil size and intersubject synchronization of gaze position). RESULTSAcute fear events led to shortening of fixation duration, suppression of blinking, as well as increase of fixation count, saccade amplitude, and pupil size. Sustained fear was in turn associated with increased pupil size and decrease in blinking and saccade amplitude. These effects remained significant when controlling for luminosity. CONCLUSIONSDuring natural vision both acute and sustained fear cause rapid reconfiguration, state dependent and individual changes in visual attention prioritizing that is accompanied by increased affective arousal.

neuroscience↗

Exposure to bullying engages social distress circuits in the adolescent and adult brain

Despite advances in understanding the psychological and social consequences of peer victimization, the immediate effects of bullying on the central nervous system remain elusive. Here we mapped the neural responses to simulated bullying in adolescents and adults and tested whether these responses are associated with real-life victimization experiences. Fifty-one adolescents aged 11-14 years, and 47 adults underwent a functional MRI (fMRI) while watching first-person videos of bullying (victimization) in the school environment, as well as neutral and positive social interactions in a similar setting. Exposure to bullying versus positive social interaction engaged the socio-emotional and threat response systems, as well as regions related to social cognition, sensory and interoceptive processing, and motor control. These responses were consistent across adolescents and adults and dependent on the current and past victimization experiences of the participants. This large-scale activation of neural systems subserving socioemotional, somatosensory, and interoceptive processing highlights how peer victimization evokes a severe stress and alarm state in the central nervous system.

neuroscience↗

Endogenous opioid receptor system mediates costly altruism in the human brain

Functional neuroimaging studies suggest that a large-scale brain network transforms others pain into its vicarious representation in the observer, potentially modulating helping behaviour. The neuromolecular basis of individual differences in vicarious pain and helping, however, have remain poorly understood. Here we investigated the role of the endogenous -opioid receptor (MOR) system - known for its role in analgesia and sociability - in altruistic costly helping. MOR density was measured with high-affinity agonist radioligand [11C]carfentanil. In a separate fMRI experiment, participants could choose to donate money to reduce the pain of the confederate who was subjected to electric shocks of varying intensity. We found that subjects were in general willing to engage in costly helping, and haemodynamic activity in amydala, anterior insula, anterior cingulate cortex, striatum, primary motor cortex, primary somatosensory cortex, and thalamus increased when participants witnessed the pain of others. These haemodynamic responses were negatively associated with MORs availability in the striatolimbic and cortical emotion circuits. In turn, haemodynamic responses during helping were positively associated with MOR availability in the anterior cingulate cortex and hippocampus. Altogether these data suggest that the endogenous MOR system modulates the processing of altruistic behaviour and costly helping in the human brain.

neuroscience↗

Dissociable neural systems for unconditioned acute and sustained fear

Fear protects organisms by increasing vigilance and preparedness, and by coordinating survival responses during life-threatening encounters. The fear circuit must thus operate on multiple timescales ranging from preparatory sustained alertness to acute fight-or-flight responses. Here we studied the brain basis of sustained (\"looming\") and acute fear using naturalistic functional magnetic resonance imaging (fMRI) enabling analysis of different time-scales of fear responses. Subjects (N = 51) watched feature-length horror movies while their hemodynamic brain activity was measured with fMRI. Time-variable intersubject correlation (ISC) was used to quantify the reliability of brain activity across participants, and seed-based phase synchronization was used for characterizing dynamic connectivity. Subjective ratings of fear were obtained from a separate sample, and were used to assess how synchronization and functional connectivity varied with emotional intensity. These data suggest that acute and sustained fear are supported by distinct neural pathways, with sustained fear amplifying mainly sensory responses, and acute fear increasing activity in brainstem, thalamus, amygdala and cingulate cortices. Sustained fear increased ISC in regions associated with acute fear, and also amplified functional connectivity within this network. The results were replicated in two independent experiments with different subject samples. The functional interplay between cortical networks involved in sustained anticipation of, and acute response to, threat involves a complex and dynamic interaction that depends on the proximity of threat, and the need to employ threat appraisals and vigilance for decision making and response selection.

neuroscience↗