Biology subjects

Chen, J.-I.

Publications and source records attributed to Chen, J.-I..

3 recordsLinked to original sources

bioRxiv2026

From language to pain: brain-behavior representations of hypnotic verbal suggestions for pain modulation

Language can shape pain by conveying conceptual information about future somatosensory experiences. However, how verbal input is encoded in the brain and how these representations are later implemented during pain modulation remains unclear. We used a standardized hypnotic procedure with fMRI to test how verbal suggestions of hypoalgesia and hyperalgesia (vs neutral control) modulate pain. We quantified convergent neural responses across individuals during both suggestion encoding and pain processing, using inter-subject correlation and multivoxel pattern similarity approaches, respectively, and related these measures to individual differences in hypnotic suggestibility using representational similarity analysis. More suggestible individuals showed similar temporal dynamics in language-related regions during encoding and more similar hypoalgesia-specific patterns in the left parahippocampal gyrus (PHG) during pain. In contrast, lower suggestibility was associated with convergent responses in sensorimotor and monitoring systems across phases, demonstrating different neural implementation in individuals less successful in converting suggestions into hypoalgesia. These findings identify the PHG as a key region linking the effect of verbal suggestions to subsequent pain relief and show that hypnotic suggestibility structures how neural dynamics during language processing translate into altered pain experiences. This study offers a mechanistic lens for understanding how medical hypnosis and language-based therapies influence pain.

neuroscience↗

bioRxiv2026

Facing pain is effortful: key role of the supplementary motor area and anterior midcingulate cortex

Pain captures attention and interferes with executive and motor processes. In the presence of pain, increasing effort may represent a compensatory mechanism to counteract pain-related disruption and maintain task performance. In this preregistered fMRI study, we investigated neural mechanisms underlying preserved task performance during pain and increased perceived effort. Forty right-handed participants performed a visuomotor force-matching task consisting of isometric handgrip contractions at a low and high force levels under individually calibrated painful or non-painful thermal stimulation. Thermal stimulation was applied to the left forearm, and participants rated the intensity of perceived effort after each isometric contraction. Maintaining task performance under pain was associated with increased perceived effort and recruited brain regions involved in pain modulation and cognitive control. Region-of-interest analysis showed perceived effort was consistently linked to decreased anterior midcingulate cortex activity, whereas supplementary motor area contributions varied depending on its role in motor execution or pain processing. Across experimental condition, motor, pain-modulatory and cognitive-control regions were associated with effort perception. Independently of condition, effort perception was modulated by ventromedial prefrontal cortex and ventral striatum. These findings indicate that effort perception is a complex phenomenon reflecting brain activity within areas involved in motor, executive and valuation processes. Significance StatementThis study advances our understanding of the neural mechanisms underlying task performance under pain and increased effort perception. Brain activity was measured during a visuomotor force-matching task performed in the presence or absence of pain. By contrasting task-related activity between painful and non-painful conditions, we identified regions associated with cognitive control and pain modulation involved in preserving task performance under pain. By correlating activity in regions of interest with ratings of perceived effort, we demonstrated the involvement of the supplementary motor area and midcingulate cortex in effort perception. These findings suggest that additional neural resources are recruited to maintain performance during pain and that the supplementary motor area and midcingulate cortex contribute to heightening the effort experienced.

neuroscience↗

bioRxiv2023

Facial expression is a distinctive behavioural marker of pain processing in the brain

Pain is a private experience observable through various verbal and non-verbal behavioural manifestations, each of which may relate to different pain-related functions. Despite the importance of understanding the cerebral mechanisms underlying those manifestations, there is currently limited knowledge on the neural correlates of the facial expression of pain. In this functional magnetic resonance imaging (fMRI) study, noxious heat stimulation was applied in healthy volunteers and we tested if previously published brain signatures of pain were sensitive to pain expression. We then applied a multivariate pattern analysis to the fMRI data to predict the facial expression of pain. Results revealed the inability of previously developed pain neurosignatures to predict the facial expression of pain. We thus propose a Facial Expression of Pain Signature (FEPS) conveying distinctive information about the brain response to nociceptive stimulations with minimal or no overlap with other pain-relevant brain signatures associated with nociception, pain ratings, thermal pain aversiveness, or pain valuation. The FEPS may provide a distinctive functional characterization of the distributed cerebral response to nociceptive pain associated with the socio-communicative role of non-verbal pain expression. This underscores the complexity of pain phenomenology by reinforcing the view that neurosignatures conceived as biomarkers must be interpreted in relation to the specific pain manifestation(s) predicted and their underlying function(s). Future studies should explore other pain-relevant manifestations and assess the specificity of the FEPS against simulated pain expressions and other types of aversive or emotional states.

neuroscience↗