title: The impact of mediodorsal thalamic lesions on olfactory attention and flavor perception.
abstract: Olfactory attention may be important in generating odor-induced tastes - an arguably universal form of synesthesia - by ensuring that the taste concurrent is captured by the nose and olfaction, not by the mouth and gustation (oral-capture). To examine the role of olfactory attention in generating odor-induced tastes and oral capture we tested a small sample (n=4) of participants with likely impairments in olfactory attention - individuals with mediodorsal thalamic nucleus (MDNT) lesions. These participants were compared to two sets of controls on tests of olfactory attention, oral capture, odor and flavor perception, and control tasks. MDNT participants demonstrated impaired olfactory attention and enhanced oral capture. Greater oral capture was associated with greater olfactory attentional impairment. These findings imply that olfactory attention may be important in attributing odor-induced tastes to the olfactory modality. However, unlike for visual binding and for the neurodevelopmental synesthesias, where attention may be necessary to demonstrate both phenomena, olfactory attention deficits did not impair flavor binding or the experience of odor-induced tastes.
authors.affiliation: Department of Psychology, Macquarie University, NSW 2109, Australia.
authors.forename: Wendy W P
authors.initials: WW
authors.lastname: Tham
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Stevenson
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Miller
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D020645:Mediodorsal Thalamic Nucleus / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology; D008875:Middle Aged; D055696:Olfactory Perception / Q000502:physiology*; D010468:Perceptual Disorders / Q000473:pathology / Q000503:physiopathology*; D012016:Reference Values; D012684:Sensory Thresholds / Q000502:physiology; D055697:Taste Perception / Q000502:physiology*