Temporal relationship between perceptual and physiological events triggered by nociceptive heat stimuli

J M Castellote,J Valls-Solé

doi:10.1038/s41598-019-39509-3

Abstract

A combined assessment tool for the perceptual-motor aspects of pain processing will be valuable to clinicians. Fifteen healthy subjects were exposed to contact-heat stimulation (Pathway, Medoc, Israel) to assess perception through a simple task (motor response or conscious appraisal of the time the stimulus was felt) or with a dual task (both responses). The outcome measure was the temporal relationship between contact heat evoked potentials (CHEPS), reaction time (RT) and conscious awareness (AW). There were different temporal profiles for CHEPs, RT and AW to changes in stimulus intensity, AW being the least affected. Performing the dual task led to a significantly more pronounced effect on RT than on AW, while CHEPS were not influenced by task performance. Our results support the dissociation between physiological, behavioral and cognitive events elicited by nociceptive stimuli. The time of conscious appraisal of stimulus occurrence is a complementary information to other responses such as evoked potentials or behavioral tasks. The combined assessment of physiological and behavioral aspects of pain processing may provide clinicians with information on the different paths followed by nociceptive afferent inputs in the central nervous system.

Highlights

The recording and analysis of contact heat evoked potentials (CHEPs) is a well-known method to examine conduction in pain pathways[1,2,3]
A preliminary comparison between men and women gave no differences for aware of stimulus perception (AW), reaction time (RT) or CHEPs (p > 0.05 for all comparisons) and, the data shown correspond to data from both www.nature.com/scientificreports
Characteristics of the CHEPs, RT and AW according to conditions and tasks

Summary

Introduction

The recording and analysis of contact heat evoked potentials (CHEPs) is a well-known method to examine conduction in pain pathways[1,2,3]. Examples can be found in the difficulties to judge if we are able to hold barehanded a hot container long enough to leave it safely on top of a distant table or whether or not a certain amount of sun exposure will burn our skin when lying on the beach. Physiological events, such as CHEPs may reflect the precise time at which the inputs reach the brain, but long-latency event-related evoked potentials are contributed in part by endogenous inputs[7] and stimulus salience[8], and their latency is not necessarily related to the time of conscious perception[6]. The first option would indicate a lineal stream in successive steps of processing sensory inputs, while the second option would indicate the engagement in the process of a flexible and adaptable circuitry to prioritize certain events according to context

Objectives

Methods

Results

Conclusion