Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/4557

Title

Investigation of changes in brain electrical activity associated with preference responses to odours

Author(s)

Owen, Caroline M.;  Patterson, John

Abstract

Traditionally, research investigating preference responses to odours is qualitative, based on subjective reports and dependent on the subject’s conscious detection of the odour stimulus. Previous research revealed changes in brain electrical activity associated with physiological responses to odours which were subjectively not detected [1]. Preliminary studies with different odours suggested changes in responses between odours and associated with reported preference for the odours [2], supporting previous reports of changes in regional activation related to hedonic responses [3, 4]. The current research was designed to further investigate these differences in responses. Subjective responses were correlated with objective physiological responses to investigate differences in perceptual responses to low concentration odours delivered during natural respiration. Eight subjects [balanced for gender, age, smoking status, handedness and olfactory ability] participated in repeated recordings of brain activity responses to d-limonene [citrus smell] and hexanoic acid [sweaty, cheese, sour smell]. Brain electrical activity was recorded with a 64-channel EGI system [saline electrodes] during delivery of air or odour. Stimulus delivery was synchronised with inspiration using a continuous respiration olfactometer [3], and presented at a ratio of three air to each odour in a pseudo-random order for five minutes recording periods. Subjective responses to the odour stimulus were assessed pre-recording. Subsequently, subjects indicated if they perceived an odour during the recording and completed preference response ratings of the odour. Subjects were placed in like and dislike groups based on their pre-recording preference responses to the odour stimulus. Neurophysiological responses to the test odour were examined and correlated with these preference groups. The brain activity responses of the odour differed in comparison to air. These responses were analysed using traditional EEG techniques to determine the relationship of the brain activity to the reported preferences. The power spectrum analysis for the like and dislike groups reflected differences in electrophysiological activation associated with preference responses, suggesting that odour preference may be reflected, in part, by these differences in the power spectrum in response to low concentrations of the odour. This analysis demonstrated a method of utilising different techniques to better quantify the neurophysiological effects of odour inhaled during natural respiration.

Publication type

Conference abstract

Research centre

Swinburne University of Technology. School of Biophysical Sciences and Electrical Engineering

Source

Annual Meeting of the Australasian Association for ChemoSensory Science (AACSS), 30 November - 1 December 2000, Melbourne, Victoria, Australia, pp. 15

Publication year

2000

Publisher

Swinburne University of Technology

Publisher URL

http://www.swinburne.edu.au/lss/SNL/presentations.html