[show abstract][hide abstract] ABSTRACT: The study of olfactory lateralization in humans has given rise to many publications, but the findings have often been contradictory. There is growing evidence to suggest that the nature of the olfactory stimulus influences the processes of lateralization. An important factor could be the trigeminal component. Indeed, most odorants simultaneously stimulate both olfactory (CN I) and trigeminal (CN V) systems which differ in terms of their central projections, ipsilaterally for CN I and contralaterally for CN V. The aim of this study was to investigate variations in psychophysiological measurements between a nasal input with low (phenyl ethyl alcohol (PEA)) and high (allyl isothiocyanate (AIC)) intranal trigeminal stimulation. In a first experiment (20 subjects), the intensity, hedonicity and irritation levels of stimulus were tested with a psychophysical evaluation to study the possible influences of perceptual characteristics. A second experiment (37 subjects) used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for both nasal inputs on either monorhinal and birhinal stimulations. Firstly, the electrodermal activity (EDA) results showed no differences between the two nostrils for PEA as well as AIC, but differences in relation to the type of stimulus, e.g. higher amplitude in response to AIC versus PEA. Secondly, the results indicated bilateral differences in EDA recordings related to the nature of the stimulus and are discussed in terms of hemispheric asymmetric activation.
Behavioural Brain Research 08/2002; 133(2):205-10. · 3.33 Impact Factor
[show abstract][hide abstract] ABSTRACT: The sex of individuals plays an important part in determining their olfactory abilities, with females generally being superior to males. The present review examines the way in which sex differences influence sensitivity, identification, familiarity, and recognition of odours. It also examines whether sex differences are more pronounced with some odours than others, and how sex differences are affected by the manner of testing. Two different explanations for the superiority of females over males in olfaction are evaluated.
The Quarterly Journal of Experimental Psychology 09/2001; 54(3):259-70. · 4.67 Impact Factor
[show abstract][hide abstract] ABSTRACT: In order to examine the reliability of lateralised behaviours, BALB/c mice were tested in three different situations: the Collins paw preference test (PPT), the rotatory swimming test (RST), and the T maze test (TMT). The results showed a significant correlation between the scores of lateralisation in the PPT and the RST, but a lack of lateralisation in the TMT. Considering the tasks involved in these tests, these results appear to support the hypothesis of close links between lateralised behaviours, emotional processes, and neural pathways.
[show abstract][hide abstract] ABSTRACT: The study of olfactory lateralization in human subjects has given rise to many publications, but the findings have often been contradictory. Most research used either birhinal or monorhinal stimulations, but rarely a comparison between these two types of olfactory input. The aim of this study was to investigate variations in psychophysiological measurements and test each side of the nose and binasal performances. This work used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for a pleasant odorant (isoamyl acetate) and an unpleasant odorant (triethylamine) in a suprathreshold concentration on 30 dextral subjects (16 females and 14 males). First, the results reported no differences between the two nostrils but differences in electrodermal activity (EDA) in relation to the odorant: 1) higher amplitude in response to unpleasant versus pleasant odorant; 2) no differences between monorhinal and birhinal stimulations for the unpleasant odour but higher amplitude in response to birhinal versus monorhinal for the pleasant odour. Second, the results showed constant bilateral differences in EDA recordings and are discussed in terms of hemispheric asymmetry activation.
Comptes Rendus de l Académie des Sciences - Series III - Sciences de la Vie 12/2000; 323(11):959-65.
[show abstract][hide abstract] ABSTRACT: The smelling behavior of 52 right-handed subjects was videotaped during tasks involving identification and recognition of different odors. Analysis showed that men more often used the right nostril than the left whatever the odor. There was no significant difference for the women. These results support a more marked cerebral asymmetry in men than in women and a main involvement of the right cerebral hemisphere in the olfactory processes at least by right-handed men.
Perceptual and Motor Skills 05/2000; 90(2):444-50. · 0.49 Impact Factor
[show abstract][hide abstract] ABSTRACT: The study of hemispheric asymmetry in olfaction in human subjects has given rise to many publications, but the findings have often been contradictory. This study used bilateral electrodermal activity recordings with unilateral stimulation as a measure of functional hemispheric asymmetry. A specific odorant (lavender) was used by monorhinic (single nostril) stimulation on 30 dextral subjects (20 females and 10 males). Intraindividually, the results showed no difference between the two nostrils, but all subjects exhibited a constant direction of electrodermal asymmetry: 20 subjects systematically showed a greater response amplitude for the right hand and 10 subjects systematically showed a greater response amplitude for the left hand, whatever hemisphere stimulated.