ETUDE DES FONCTIONS ATTENTIONNELLES ET EXECUTIVES CHEZ L'ENFANT PAR LES POTENTIELS EVOQUES ENDOGENES (APPLICATION AUX SYNDROMES D'HYPERACTIVITE AVEC DEFICIT DE L'ATTENTION)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Interference of Cellular Phone Conversations with Visuomotor Tasks: An ERP Study

This version of the article may not completely replicate the final authoritative version published in Journal of Psychophysiology at https://doi.org/10.1027//0269-8803.15.1.14. It is not the version of record and is therefore not suitable for citation. Please do not copy or cite without the permission of the author(s)The use of mobile phones has been shown to increase drivers’ reaction times (RTs), but whether this results from interference with attention, stimulus identification, or response production remains unclear. We recorded RTs and event-related brain potentials (ERPs) reflecting speed of stimulus processing, attentional allocation, and preparedness to respond during a visual reaction task performed with or without the concomitant use of a mobile phone, in either “hands-free” or “phone-in-hand” operating modes. As expected, maintaining a phone conversation increased RTs to visual targets, this effect being associated with complex ERP effects. Phone conversations did not appear to delay target detection times, as assessed by N2–P3 latencies, but did significantly decrease stimulus-induced alerting and attentional allocation (P3 amplitude) and interfered with motor preparation processes (readiness potential). P3 amplitude drop was identical whatever the mode of phone use, while decrease of readiness potential was progressive from the “hands-free” to the “phone-in-hand” condition. These results suggest that two mechanisms contributed to degrade performance in this experiment: first, a general decrease of attention to sensory inputs, characteristic of “dual-task” situations, probably acting through a delay in sensory-motor transfer times. This effect was independent of whether the phone was handled or “hands-free.” Conversely, the second factor was specifically sensitive to manipulation of the phone and caused a weakening of the readiness to respond with a motor act.This work was supported by the “MAIF Foundation for Acident Research” (“Fondation MAIF de Recherche sur les Risques Accidentels,” and benefited from discussions with Dr. G. Pachiaudi and A. Chapon, researchers at the INRETS (Institut National sur la Recherche sur les Transports et leur Sécurité)S

INVOLUNTARY ORIENTING OF ATTENTION TO NOCICEPTIVE EVENTS. NEURAL AND BEHAVIORAL SIGNATURES.

Pain can involuntarily capture attention and disrupt pain-unrelated cognitive activities. The brain mechanisms of these effects were explored by laser- and visual-evoked potentials. Consecutive nociceptive laser stimuli and visual stimuli were delivered in pairs. Subjects were instructed to ignore nociceptive stimuli while performing a task on visual targets. Because involuntary attention is particularly sensitive to novelty, in some trials (17%) unexpected laser stimuli were delivered on a different hand area (location-deviant) relative to the more frequent standard laser stimuli. As compared to frequent standard laser stimuli, deviant stimuli enhanced all nociceptive evoked brain potentials (laser N1, N2, P2a, P2b). Deviant laser stimuli also decreased the amplitude of late-latency evoked responses (visual N2-P3) to the subsequent visual targets and delayed reaction times to them. The data confirm that nociceptive processing competes with pain-unrelated cognitive activities for attentional resources, and that concomitant nociceptive events affect behavior by depressing attention allocation to ongoing cognitive processing. The laser-evoked potential magnitude reflected the engagement of attention to the novel nociceptive stimuli. We conclude that the laser-evoked potentials index the activity of a neural system involved in the detection of novel salient stimuli in order to focus attention and prioritize action to potentially damaging dangers

EEG changes reflecting pain: is alpha suppression better than gamma enhancement?

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Cold‐evoked potentials in clinical practice: A head‐to‐head contrast with laser‐evoked responses

International audienceAbstractBackground: Innocuous cooling of the skin activates cold-specific Aδ fibres, and hence, the recording of cold-evoked potentials (CEPs) may improve the objective assessment of human thermo-nociceptive function. While the feasibility of CEP recordings in healthy humans has been reported, their reliability and diagnostic use in clinical conditions have not been documented.Methods: Here, we report the results of CEP recordings in 60 consecutive pa- tients with suspected neuropathic pain, compared with laser-evoked potentials (LEPs) which are the gold standard for thermo-algesic instrumental assessment. Results: CEP recording was a well-tolerated procedure, with only ~15 min of sur- plus in exam duration. The reproducibility and signal-to-noise ratio of CEPs were lower than those of LEPs, in particular for distal lower limbs (LLs). While laser responses were interpretable in all patients, CEPs interpretation was inconclu- sive in 5/60 because of artefacts or lack of response on the unaffected side. Both techniques yielded concordant results in 73% of the patients. In 12 patients, CEPs yielded abnormal values while LEPs remained within normal limits; 3 of these patients had clinical symptoms limited to cold sensations, including cold-heat transformation.Conclusions: CEPs appear as a useful technique for exploring pain/temperature systems. Advantages are low cost of equipment and innocuity. Disadvantages are low signal-to-noise ratio for LL stimulation, and sensitivity to fatigue/habitu- ation. Joint recording of CEPs and LEPs can increase the sensitivity of neuro- physiological techniques to thin fibre- spinothalamic lesions, in particular, when abnormalities of cold perception predominate.Significance: Recording of cold-evoked potentials is a well-tolerated, inexpen- sive and easy-to-use procedure that can be helpful in the diagnosis of abnormali- ties in the thin fibre- spinothalamic pathways. Supplementing LEPs with CEPs allows consolidating the diagnosis and, for some patients suffering from symp- toms limited only to cold, CEPs but not LEPs may allow the diagnosis of thin fibre pathology. Optimal CEP recording conditions are important to overcome the low signal-to-noise ratio and habituation phenomena, which are less favourable than with LEPs

Hyperalgesia when observing pain-related images is a genuine bias in perception and enhances autonomic responses

International audienceObserving pain in others can enhance our own pain. Two aspects of this effect remain unknown or controversial: first, whether it depends on the 'painfulness' of the visual stimulus; second, whether it reflects a genuine bias in perception or rather a bias in the memory encoding of the percept. Pain ratings and vegetative skin responses were recorded while 21 healthy volunteers received electric nociceptive shocks under three experimental conditions: (i) observing a painful contact between the body and a harmful object; (ii) observing a non-painful body contact, (iii) observing a control scene where the body and the object are not in contact. Pain reports and vegetative responses were enhanced exclusively when the subjects observed a painful body contact. The effect on perception was immediate, abated 3 sec after the shock, and positively correlated with the magnitude of vegetative arousal. This suggests that (a) hyperalgesia during observation of painful scenes was induced by their pain-related nature, and not by the simple body contact, and (b) hyperalgesia emerged from a very rapid bias in the perceptual encoding of the stimulus, and was not the result of a retrospective bias in memory recollection. Observing pain-depicting scenes can modify the processing of concomitant somatic stimuli, increasing their arousal value and shifting perception toward more painful levels