The Effect of Body Position on Flavor Release and Perception: Implications for fMRI Studies J. Hort & S. Redureau & T. Hollowood & L. Marciani & S. Eldeghaidy & K. Head & J. Busch & R. C. Spiller & S. Francis & P. A. Gowland & A. J. Taylor Received: 10 September 2008 / Accepted: 9 October 2008 / Published online: 31 October 2008 # 2008 Springer Science + Business Media, LLC Abstract Increasingly functional magnetic resonance im- aging (fMRI) of the brain is being used to assess the cortical response to flavor perception. fMRI requires the subject to adopt a supine position; hence, if the results from such experiments are to be meaningfully extrapolated to flavor perception, it is pertinent to establish whether body position has a significant impact on consumers’ sensitivity to flavor. Body position is known to impact on some aspects of sensory perception, but no studies have reported the effect of body position on retronasal flavor perception. In this study, A/Not-A tests (ISO 1987), together with sureness ratings, were performed to evaluate subjects’ (n = 10) ability to differentiate between two subtly different emulsion samples under two conditions: seated in a quiet sensory booth environment and supine in a 3 T fMRI scanner mimicking real scanning conditions. In vivo volatile release was also measured in both seated and supine positions using atmospheric pressure chemical ionization mass spectrometry. Results indicated that body position had some impact on volatile release, but no overall effect on subject’ s ability to discriminate between the two samples was observed. Consequently, brain imaging data collected in this context at least would have direct relevance to sensory perception data. However, more extensive research is required to fully understand the impact of body position on flavor perception and release. Keywords Body Position . Brain Imaging . Flavor Release . Retronasal Flavor Perception Introduction Not surprisingly, the technique of functional magnetic resonance imaging (fMRI) is increasingly being used to study the neural pathways of flavor perception(Small et al. 2004b; Small and Prescott 2005). The perception of flavor normally involves the consumption of fairly large liquid samples in an upright position. In the fMRI laboratory setting, however, small quantities of liquid samples are often delivered either through tubes with the subjects’ swallowing several seconds after stimulus delivery or via taste flow chambers applied to the tongue (Bujas et al. 1991;O’Doherty et al. 2001; de Araujo et al. 2003; De Araujo and Rolls 2004; Kringelbach et al. 2004; Small et al. 2004a). These methods limit the assessment of flavor as stimuli are delivered solely to a small area of the mouth, while flavor perception is universally interpreted as a multisensory process, including the whole mouth as well as throat and nose. An fMRI protocol, which eliminates this limitation by spraying samples to disperse stimuli across the tongue and other mouth surfaces and, most notably, to allow subjects to swallow immediately following stimulus delivery to transport the volatile component of flavor to the Chem. Percept. (2008) 1:253–257 DOI 10.1007/s12078-008-9034-0 J. Hort (*) : S. Redureau : T. Hollowood : A. J. Taylor Division of Food Sciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK e-mail: Joanne.hort@nottingham.ac.uk L. Marciani : S. Eldeghaidy : K. Head : S. Francis : P. A. Gowland Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, UK L. Marciani : R. C. Spiller Wolfson Digestive Diseases Centre, QMC, Nottingham, UK J. Busch Unilever R&D Vlaardingen, Vlaardingen, the Netherlands