André Mouraux | UCLouvain (University of Louvain) (original) (raw)
Books by André Mouraux
Thèse présentée en vue de l'obtention du grade de Docteur en Sciences biomédicales Orientation: N... more Thèse présentée en vue de l'obtention du grade de Docteur en Sciences biomédicales Orientation: Neurosciences 2005 2 Cover figure: 3D representation of the time-frequency estimation of average EEG oscillation amplitude changes following CO 2 laser stimulation. Laser stimulus concomitantly activated Aδ-and C-fiber cutaneous nociceptors. Time-axis runs from left to right. Frequency-axis runs from back to front. See figure 3-3 for details.
Papers by André Mouraux
Trials, 2021
Background IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming a... more Background IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming at profiling a set of functional biomarkers of drug effects on the nociceptive system that could serve to accelerate the future development of analgesics, by providing a quantitative understanding between drug exposure and effects of the drug on nociceptive signal processing in human volunteers. IMI2-PainCare-BioPain-RCT3 will focus on biomarkers derived from non-invasive electroencephalographic (EEG) measures of brain activity. Methods This is a multisite single-dose, double-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD) and pharmacokinetic (PK) study in healthy subjects. Biomarkers derived from scalp EEG measurements (laser-evoked brain potentials [LEPs], pinprick-evoked brain potentials [PEPs], resting EEG) will be obtained before and three times after administration of three medications known to act on the nociceptive system (lacosamide, pregaba...
PLOS Biology, 2016
The insula, particularly its posterior portion, is often regarded as a primary cortex for pain. H... more The insula, particularly its posterior portion, is often regarded as a primary cortex for pain. However, this interpretation is largely based on reverse inference, and a specific involvement of the insula in pain has never been demonstrated. Taking advantage of the high spatiotemporal resolution of direct intracerebral recordings, we investigated whether the human insula exhibits local field potentials (LFPs) specific for pain. Forty-seven insular sites were investigated. Participants received brief stimuli belonging to four different modalities (nociceptive, vibrotactile, auditory, and visual). Both nociceptive stimuli and non-nociceptive vibrotactile, auditory, and visual stimuli elicited consistent LFPs in the posterior and anterior insula, with matching spatial distributions. Furthermore, a blind source separation procedure showed that nociceptive LFPs are largely explained by multimodal neural activity also contributing to nonnociceptive LFPs. By revealing that LFPs elicited by nociceptive stimuli reflect activity unrelated to nociception and pain, our results confute the widespread assumption that these brain responses are a signature for pain perception and its modulation.
Anesthesie-Reanimation - Epreuve corrigee par l'auteur. Disponible en ligne depuis le 06/03/2018
It is increasingly recognized that motor routines dynamically shape the processing of sensory inf... more It is increasingly recognized that motor routines dynamically shape the processing of sensory inflow (e.g. hand movements to feel a texture or identify an object). These exploratory movements are often rhythmic, and it has been suggested that movement-perception shaping could be supported by movement-induced neural entrainment. In auditory perception, the shaping of perception by movement has been reported in humans using behavioral methods, but neurophysiological evidence is lacking. To fill this gap, we took advantage of a specific context, music. Participants listened to a cyclical rhythm before and after moving the body on this rhythm according to a specific meter. We found that the brain responses to the rhythm as recorded with EEG after body movement was significantly enhanced at meter frequencies to which participants had moved. These results provide evidence that body movement can shape selectively the subsequent perception and neural representation of auditory rhythms.
Whether the cortical processing of nociceptive input relies on the activity of nociceptive-specif... more Whether the cortical processing of nociceptive input relies on the activity of nociceptive-specific neurons or whether it relies on the activity of non-specific neuronal populations remains a matter of intense debate. Here, we address this question using EEG “frequency-tagging” of steady-state evoked potentials (SS-EPs) combined with an intermodal selective attention paradigm to test whether the cortical processing of nociceptive input relies on nociceptive-specific neuronal populations which can be selectively modulated by top-down attention. Specifically, we hypothesized that if the cortical processing of nociceptive and non-nociceptive sensory inputs involves distinct neuronal populations, selective attention would selectively enhance the SS-EPs elicited by the attended stream of sensory input. Conversely, if the cortical processing of the two sensory inputs involves the same neuronal populations, selective attention would indistinctly enhance the responses elicited by the attend...
PLOS ONE
Thermosensation is crucial for humans to probe the environment and detect threats arising from no... more Thermosensation is crucial for humans to probe the environment and detect threats arising from noxious heat or cold. Over the last years, EEG frequency-tagging using long-lasting periodic radiant heat stimulation has been proposed as a means to study the cortical processes underlying tonic heat perception. This approach is based on the notion that periodic modulation of a sustained stimulus can elicit synchronized periodic activity in the neuronal populations responding to the stimulus, known as a steady-state response (SSR). In this paper, we extend this approach using a contact thermode to generate both heat-and coldevoked SSRs. Furthermore, we characterize the temporal dynamics of the elicited responses, relate these dynamics to perception, and assess the effects of displacing the stimulated skin surface to gain insight on the heat-and cold-sensitive afferents conveying these responses. Two experiments were conducted in healthy volunteers. In both experiments, noxious heat and innocuous cool stimuli were applied during 75 seconds to the forearm using a Peltier-based contact thermode, with intensities varying sinusoidally at 0.2 Hz. Displacement of the thermal stimulation on the skin surface was achieved by independently controlling the Peltier elements of the thermal probe. Continuous intensity ratings to sustained heat and cold stimulation were obtained in the first experiment with 14 subjects, and the EEG was recorded in the second experiment on 15 subjects. Both contact heat and cool stimulation elicited periodic EEG responses and percepts. Compared to heat stimulation, the responses to cool stimulation had a lower magnitude and shorter latency. All responses tended to habituate along time, and this response attenuation was most pronounced for cool compared to warm stimulation, and for stimulation delivered using a fixed surface compared to a variable surface.
PLOS ONE, Apr 23, 2020
Thermosensation is crucial for humans to probe the environment and detect threats arising from no... more Thermosensation is crucial for humans to probe the environment and detect threats arising from noxious heat or cold. Over the last years, EEG frequency-tagging using long-lasting periodic radiant heat stimulation has been proposed as a means to study the cortical processes underlying tonic heat perception. This approach is based on the notion that periodic modulation of a sustained stimulus can elicit synchronized periodic activity in the neuronal populations responding to the stimulus, known as a steady-state response (SSR). In this paper, we extend this approach using a contact thermode to generate both heat-and coldevoked SSRs. Furthermore, we characterize the temporal dynamics of the elicited responses, relate these dynamics to perception, and assess the effects of displacing the stimulated skin surface to gain insight on the heat-and cold-sensitive afferents conveying these responses. Two experiments were conducted in healthy volunteers. In both experiments, noxious heat and innocuous cool stimuli were applied during 75 seconds to the forearm using a Peltier-based contact thermode, with intensities varying sinusoidally at 0.2 Hz. Displacement of the thermal stimulation on the skin surface was achieved by independently controlling the Peltier elements of the thermal probe. Continuous intensity ratings to sustained heat and cold stimulation were obtained in the first experiment with 14 subjects, and the EEG was recorded in the second experiment on 15 subjects. Both contact heat and cool stimulation elicited periodic EEG responses and percepts. Compared to heat stimulation, the responses to cool stimulation had a lower magnitude and shorter latency. All responses tended to habituate along time, and this response attenuation was most pronounced for cool compared to warm stimulation, and for stimulation delivered using a fixed surface compared to a variable surface.
Frontiers in Pharmacology
Frontiers in Neuroscience
The Journal of physiology, 2018
A recent animal study showed that high frequency electrical stimulation (HFS) of C-fibres induces... more A recent animal study showed that high frequency electrical stimulation (HFS) of C-fibres induces a gliogenic heterosynaptic long-term potentiation at the spinal cord that is hypothesized to mediate secondary hyperalgesia in humans. Here this hypothesis was tested by predominantly activating C-fibre nociceptors in the area of secondary mechanical hyperalgesia induced by HFS in humans. It is shown that heat perception elicited by stimuli predominantly activating C-fibre nociceptors is greater, as compared to the control site, after HFS in the area of secondary mechanical hyperalgesia. This is the first study that confirms in humans the involvement of C-fibre nociceptors in the changes in heat sensitivity in the area of secondary mechanical hyperalgesia induced by HFS. It has recently been shown that high frequency electrical stimulation (HFS) of C-fibres induces a gliogenic heterosynaptic long-term potentiation (LTP) at the spinal cord in animals, which has been hypothesized to be th...
Frontiers in behavioral neuroscience, 2017
Simultaneous execution of cognitive and sensorimotor tasks is critical in daily life. Here, we ex... more Simultaneous execution of cognitive and sensorimotor tasks is critical in daily life. Here, we examined whether dexterous manipulation, a highly habitual and seemingly automatic behavior, involves high order cognitive functions. Specifically, we explored the impact of reducing available cognitive resources on the performance of a precision grip-lift task in healthy participants of three age groups (18-30, 30-60 and 60-75 years). Participants performed a motor task in isolation (M), in combination with a low-load cognitive task (M + L), and in combination with a high-load cognitive task (M + H). The motor task consisted in grasping, lifting and holding an apparatus instrumented with force sensors to monitor motor task performance. In the cognitive task, a list of letters was shown briefly before the motor task. After completing the motor task, one letter of the list was shown, and participants reported the following letter of the list. In M + L, letters in the list followed the alpha...
Thèse présentée en vue de l'obtention du grade de Docteur en Sciences biomédicales Orientation: N... more Thèse présentée en vue de l'obtention du grade de Docteur en Sciences biomédicales Orientation: Neurosciences 2005 2 Cover figure: 3D representation of the time-frequency estimation of average EEG oscillation amplitude changes following CO 2 laser stimulation. Laser stimulus concomitantly activated Aδ-and C-fiber cutaneous nociceptors. Time-axis runs from left to right. Frequency-axis runs from back to front. See figure 3-3 for details.
Trials, 2021
Background IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming a... more Background IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming at profiling a set of functional biomarkers of drug effects on the nociceptive system that could serve to accelerate the future development of analgesics, by providing a quantitative understanding between drug exposure and effects of the drug on nociceptive signal processing in human volunteers. IMI2-PainCare-BioPain-RCT3 will focus on biomarkers derived from non-invasive electroencephalographic (EEG) measures of brain activity. Methods This is a multisite single-dose, double-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD) and pharmacokinetic (PK) study in healthy subjects. Biomarkers derived from scalp EEG measurements (laser-evoked brain potentials [LEPs], pinprick-evoked brain potentials [PEPs], resting EEG) will be obtained before and three times after administration of three medications known to act on the nociceptive system (lacosamide, pregaba...
PLOS Biology, 2016
The insula, particularly its posterior portion, is often regarded as a primary cortex for pain. H... more The insula, particularly its posterior portion, is often regarded as a primary cortex for pain. However, this interpretation is largely based on reverse inference, and a specific involvement of the insula in pain has never been demonstrated. Taking advantage of the high spatiotemporal resolution of direct intracerebral recordings, we investigated whether the human insula exhibits local field potentials (LFPs) specific for pain. Forty-seven insular sites were investigated. Participants received brief stimuli belonging to four different modalities (nociceptive, vibrotactile, auditory, and visual). Both nociceptive stimuli and non-nociceptive vibrotactile, auditory, and visual stimuli elicited consistent LFPs in the posterior and anterior insula, with matching spatial distributions. Furthermore, a blind source separation procedure showed that nociceptive LFPs are largely explained by multimodal neural activity also contributing to nonnociceptive LFPs. By revealing that LFPs elicited by nociceptive stimuli reflect activity unrelated to nociception and pain, our results confute the widespread assumption that these brain responses are a signature for pain perception and its modulation.
Anesthesie-Reanimation - Epreuve corrigee par l'auteur. Disponible en ligne depuis le 06/03/2018
It is increasingly recognized that motor routines dynamically shape the processing of sensory inf... more It is increasingly recognized that motor routines dynamically shape the processing of sensory inflow (e.g. hand movements to feel a texture or identify an object). These exploratory movements are often rhythmic, and it has been suggested that movement-perception shaping could be supported by movement-induced neural entrainment. In auditory perception, the shaping of perception by movement has been reported in humans using behavioral methods, but neurophysiological evidence is lacking. To fill this gap, we took advantage of a specific context, music. Participants listened to a cyclical rhythm before and after moving the body on this rhythm according to a specific meter. We found that the brain responses to the rhythm as recorded with EEG after body movement was significantly enhanced at meter frequencies to which participants had moved. These results provide evidence that body movement can shape selectively the subsequent perception and neural representation of auditory rhythms.
Whether the cortical processing of nociceptive input relies on the activity of nociceptive-specif... more Whether the cortical processing of nociceptive input relies on the activity of nociceptive-specific neurons or whether it relies on the activity of non-specific neuronal populations remains a matter of intense debate. Here, we address this question using EEG “frequency-tagging” of steady-state evoked potentials (SS-EPs) combined with an intermodal selective attention paradigm to test whether the cortical processing of nociceptive input relies on nociceptive-specific neuronal populations which can be selectively modulated by top-down attention. Specifically, we hypothesized that if the cortical processing of nociceptive and non-nociceptive sensory inputs involves distinct neuronal populations, selective attention would selectively enhance the SS-EPs elicited by the attended stream of sensory input. Conversely, if the cortical processing of the two sensory inputs involves the same neuronal populations, selective attention would indistinctly enhance the responses elicited by the attend...
PLOS ONE
Thermosensation is crucial for humans to probe the environment and detect threats arising from no... more Thermosensation is crucial for humans to probe the environment and detect threats arising from noxious heat or cold. Over the last years, EEG frequency-tagging using long-lasting periodic radiant heat stimulation has been proposed as a means to study the cortical processes underlying tonic heat perception. This approach is based on the notion that periodic modulation of a sustained stimulus can elicit synchronized periodic activity in the neuronal populations responding to the stimulus, known as a steady-state response (SSR). In this paper, we extend this approach using a contact thermode to generate both heat-and coldevoked SSRs. Furthermore, we characterize the temporal dynamics of the elicited responses, relate these dynamics to perception, and assess the effects of displacing the stimulated skin surface to gain insight on the heat-and cold-sensitive afferents conveying these responses. Two experiments were conducted in healthy volunteers. In both experiments, noxious heat and innocuous cool stimuli were applied during 75 seconds to the forearm using a Peltier-based contact thermode, with intensities varying sinusoidally at 0.2 Hz. Displacement of the thermal stimulation on the skin surface was achieved by independently controlling the Peltier elements of the thermal probe. Continuous intensity ratings to sustained heat and cold stimulation were obtained in the first experiment with 14 subjects, and the EEG was recorded in the second experiment on 15 subjects. Both contact heat and cool stimulation elicited periodic EEG responses and percepts. Compared to heat stimulation, the responses to cool stimulation had a lower magnitude and shorter latency. All responses tended to habituate along time, and this response attenuation was most pronounced for cool compared to warm stimulation, and for stimulation delivered using a fixed surface compared to a variable surface.
PLOS ONE, Apr 23, 2020
Thermosensation is crucial for humans to probe the environment and detect threats arising from no... more Thermosensation is crucial for humans to probe the environment and detect threats arising from noxious heat or cold. Over the last years, EEG frequency-tagging using long-lasting periodic radiant heat stimulation has been proposed as a means to study the cortical processes underlying tonic heat perception. This approach is based on the notion that periodic modulation of a sustained stimulus can elicit synchronized periodic activity in the neuronal populations responding to the stimulus, known as a steady-state response (SSR). In this paper, we extend this approach using a contact thermode to generate both heat-and coldevoked SSRs. Furthermore, we characterize the temporal dynamics of the elicited responses, relate these dynamics to perception, and assess the effects of displacing the stimulated skin surface to gain insight on the heat-and cold-sensitive afferents conveying these responses. Two experiments were conducted in healthy volunteers. In both experiments, noxious heat and innocuous cool stimuli were applied during 75 seconds to the forearm using a Peltier-based contact thermode, with intensities varying sinusoidally at 0.2 Hz. Displacement of the thermal stimulation on the skin surface was achieved by independently controlling the Peltier elements of the thermal probe. Continuous intensity ratings to sustained heat and cold stimulation were obtained in the first experiment with 14 subjects, and the EEG was recorded in the second experiment on 15 subjects. Both contact heat and cool stimulation elicited periodic EEG responses and percepts. Compared to heat stimulation, the responses to cool stimulation had a lower magnitude and shorter latency. All responses tended to habituate along time, and this response attenuation was most pronounced for cool compared to warm stimulation, and for stimulation delivered using a fixed surface compared to a variable surface.
Frontiers in Pharmacology
Frontiers in Neuroscience
The Journal of physiology, 2018
A recent animal study showed that high frequency electrical stimulation (HFS) of C-fibres induces... more A recent animal study showed that high frequency electrical stimulation (HFS) of C-fibres induces a gliogenic heterosynaptic long-term potentiation at the spinal cord that is hypothesized to mediate secondary hyperalgesia in humans. Here this hypothesis was tested by predominantly activating C-fibre nociceptors in the area of secondary mechanical hyperalgesia induced by HFS in humans. It is shown that heat perception elicited by stimuli predominantly activating C-fibre nociceptors is greater, as compared to the control site, after HFS in the area of secondary mechanical hyperalgesia. This is the first study that confirms in humans the involvement of C-fibre nociceptors in the changes in heat sensitivity in the area of secondary mechanical hyperalgesia induced by HFS. It has recently been shown that high frequency electrical stimulation (HFS) of C-fibres induces a gliogenic heterosynaptic long-term potentiation (LTP) at the spinal cord in animals, which has been hypothesized to be th...
Frontiers in behavioral neuroscience, 2017
Simultaneous execution of cognitive and sensorimotor tasks is critical in daily life. Here, we ex... more Simultaneous execution of cognitive and sensorimotor tasks is critical in daily life. Here, we examined whether dexterous manipulation, a highly habitual and seemingly automatic behavior, involves high order cognitive functions. Specifically, we explored the impact of reducing available cognitive resources on the performance of a precision grip-lift task in healthy participants of three age groups (18-30, 30-60 and 60-75 years). Participants performed a motor task in isolation (M), in combination with a low-load cognitive task (M + L), and in combination with a high-load cognitive task (M + H). The motor task consisted in grasping, lifting and holding an apparatus instrumented with force sensors to monitor motor task performance. In the cognitive task, a list of letters was shown briefly before the motor task. After completing the motor task, one letter of the list was shown, and participants reported the following letter of the list. In M + L, letters in the list followed the alpha...
Journal of the Royal Society, Interface, 2017
When we touch an object or explore a texture, frictional strains are induced by the tactile inter... more When we touch an object or explore a texture, frictional strains are induced by the tactile interactions with the surface of the object. Little is known about how these interactions are perceived, although it becomes crucial for the nascent industry of interactive displays with haptic feedback (e.g. smartphones and tablets) where tactile feedback based on friction modulation is particularly relevant. To investigate the human perception of frictional strains, we mounted a high-fidelity friction modulating ultrasonic device on a robotic platform performing controlled rubbing of the fingertip and asked participants to detect induced decreases of friction during a forced-choice task. The ability to perceive the changes in friction was found to follow Weber's Law of just noticeable differences, as it consistently depended on the ratio between the reduction in tangential force and the pre-stimulation tangential force. The Weber fraction was 0.11 in all conditions demonstrating a very ...