Measuring Temperature and Phantom Taste Related Brain Activity in - PowerPoint PPT Presentation

Measuring Temperature and Phantom Taste Related Brain Activity in Thermal Tasters Compared to Thermal non Tasters M. Skinner* 1,2 , S. Eldeghaidy 2 , R. Ford 1 , T. Giesbrecht 3 , A. Thomas 3 , S. Francis 2 , J. Hort 1 . 1 Sensory Science Centre, University of Nottingham, UK. 2 Sir Peter Mansfield Imaging Centre, University of Nottingham, UK. 3 Unilever R&D, Port Sunlight, UK.

What is thermal taster status? • Salty Sweet Sour • Umami • Metallic WARMING COOLING • Minty stimuli stimuli • Spicy Bitter (Yang et al , 2014) (Cruz & Green, 2000) Food Choice? Thermal taste phenotypes • Thermal taster (TT) • Thermal non taster (TnT) TTs are more sensitive to other oral stimuli • Taste • Trigeminal (Hort et al , 2016; Green & George, 2004) 2

Exploring thermal taste phenotypes Multidisciplinary approach Sensory Science & functional Magnetic Resonance Imaging (fMRI) • Perceptual response Captured by sensory evaluation techniques • Brain activation Captured by fMRI techniques • Brain activation maps show areas of the • brain involved in the response to a stimulus 3

Study aims Identify mechanisms involved in the phantom taste response? Perceptual response Can we identify the temperature range at which phantom • taste is perceived during temperature stimulation? Does this differ across TTs? • Brain response Do we see activation in the gustatory cortex when phantom • taste is reported? Is there a difference in temperature related brain activation in • the somatosensory cortex across thermal taste phenotypes? 4

Thermal taste phenotyping Classify TT/TnT • Measure perceived temperature intensity • Warming trial Cooling trial 2 replicates Recruited General labelled magnitude scale 12 TT/12 TnT • (gLMS) 5

Modified phantom taste testing 5°C trial 40°C trial Rating Rating Temporal taste response 10 replicates 6

Reproducibility of phantom taste Phantom taste is reproducibly reported across replicates • Phantom taste is perceived at a specific temperature range • 7

Inter-individual responses 8

Inter-individual responses TTs perceive phantom taste at different temperature ranges 9

fMRI brain imaging • 3 T Philips Achieva scanner, 32-element SENSE head coil • fMRI data acquired with double-echo gradient EPI (TE: 20 ms, 45 ms), 3mm3 isotropic voxel size, 36 transverse slices, TR = 2.5 s 10

fMRI testing Subject 07 40°C trial Control task 5°C trial Subject 07 11

Phantom taste related brain activation in TTs Brain activation in regions associated with taste processing in TTs Taste cortex (anterior insula) Are gustatory nerve fibres activated by temperature in TTs? Is ‘phantom’ taste really a phantom? fMRI data analysed by Dr Sally Eldghaidy-Sir Peter Mansfield Imaging Centre UoN 12

Temperature response across thermal taste phenotypes Oral somatosensory areas TTs have greater temperature related brain activation than TnTs fMRI data analysed by Dr Sally Eldghaidy-Sir Peter Mansfield Imaging Centre UoN 13

Conclusions • TTs perceive phantom taste at variable temperature ranges during the temperature trials • Brain regions associated with taste processing are activated in response to temperature stimulation in TTs, accounting for the perceived ‘phantom’ taste • TTs have greater temperature related brain activation than TnTs These findings aid in elucidating the mechanism/s driving phantom taste perception and the heightened oral sensitivity to temperature in TTs 14

Thank you for your attention! Acknowledgments SPMIC SSC Unilever • Joanne Hort • Susan Francis • Anna Thomas • Rebecca Ford • Sally Eldeghaidy • Timo Giesbrecht • Martha Skinner • Marco Hoeksma www.nottingham.ac.uk/biosciences/research/research-themes/taste-map/taste-map.aspx 15