Chemosensory Perception: A Review on Electrophysiological Methods in “Cognitive Neuro-Olfactometry”

Invitto Invitto,Grasso Grasso

doi:10.3390/chemosensors7030045

Abstract

Various brain imaging techniques are available, but few are specifically designed to visualize chemical sensory and, in particular, olfactory processing. This review describes the results of quantitative and qualitative studies that have used electroencephalography (EEG) and magneto-encephalography (MEG) to evaluate responses to olfactory stimulation (OS). EEG and MEG are able to detect the components of chemosensory event-related potentials (CSERPs) and the cortical rhythms associated with different types of OS. Olfactory studies are filling the gaps in both the developmental field of the life cycle (from newborns to geriatric age) and the clinical and basic research fields, in a way that can be considered the modern “cognitive neuro-olfactometry”.

Highlights

Introduction to Electrophysiological Techniques and ChemicalPerceptionNeuroimaging techniques allow us to investigate the neuronal mechanisms underlying information processing, and are an indispensable tool in efforts to gain a greater understanding of how human behaviour is related to sensations and perceptions
There are no substantial differences between the olfactory event-related potentials (OERPs) averages that follow the normal event-related potentials (ERP) processing, as the tasks with OERP can take into account many electrophysiological aspects; these aspects do not depend on whether the stimulus is chemical or not, but on the type of component the researcher needs to consider
We speak instead of putative pheromone when the chemical substance related to the social odour is Chopra used EEG to record chemosensory event-related potentials (CSERPs), investigating olfactory sensitivity to social odour and quantified precisely in its dosage and in its chemical composition

Summary

Introduction to Electrophysiological Techniques and Chemical Perception

Neuroimaging techniques allow us to investigate the neuronal mechanisms underlying information processing, and are an indispensable tool in efforts to gain a greater understanding of how human behaviour is related to sensations and perceptions. The EEG artefacts can normally be caused by small muscular contractions of the face, due to the inhalation of the chemical substance through breathing This can be solved by using a good olfactometer, which allows a correct and precise stimulation so that the subject is free to breathe and inhale without having to make many muscular adjustments (especially those of the face, which are very recorded by the electrodes). There are no substantial differences between the OERP averages that follow the normal ERP processing, as the tasks with OERP can take into account many electrophysiological aspects; these aspects do not depend on whether the stimulus is chemical or not, but on the type of component the researcher needs to consider.

Example

Magneto-Encephalography and Chemical Perception

Chemosensation and the Peripheral Nervous System

Findings

Developmental Olfactory Electroencephalography in Infant Research