The aim of this thesis is to examine where in the human brain sensory and affective processing of taste takes place. Two patient studies and two neuroimaging studies were performed. Taste intensity perception was evaluated in patients with unilateral resection from the AMTL, and in healthy control subjects. The results from two independent experiments indicate that AMTL removal leads to taste intensity perception changes, including decreases in the accuracy of judging actual concentrations of taste solutions, and increases in the perceived intensities of an aversive bitter taste. It is possible that the latter result reflects a potentiation of the aversiveness of bitter as opposed to, or in addition to a change in intensity perception of taste intensity alone. / To define more precisely the regions of the insula/operculum and orbitofrontal cortex (OFC) {putative primary and secondary gustatory regions (PGA and SGA, respectively)} that are activated by gustatory stimulation in humans, standardized Talairach coordinates from all available studies were compiled and plotted onto an averaged MRI image. As in non-human primates, it is likely that the human PGA is represented in several regions within the middle to anterior insula, and in frontal and parietal opercula. The precise location of the human SGA is less clear, but is likely within the caudal region of the OFC. / In the final study, successive [15O]H2O PET scans were performed on volunteers as they ate chocolate to beyond satiety. Thus, the sensory stimulus was held constant while its reward value was manipulated by feeding. As predicted, modulation was observed in both the primary and secondary gustatory regions, corresponding to the regions identified in the previous study. This finding suggests overlapping representation of sensory and affective processing of taste in humans. Additionally, different groups of structures were selectively recruited depending on whether subjects were eating chocolate when they were highly motivated to eat or highly motivated not to eat. / In summary, the work contained within this thesis suggests that sensory and affective processing of taste occurs in the AMTL, PGA, and SGA. Such an interaction marks a departure from classical theories of sensory organization based upon studies performed largely in the visual modality.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.37842 |
| Date | January 2000 |
| Creators | Small, Dana. |
| Contributors | Jones-Gotman, Marilyn (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Psychology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001809660, proquestno: NQ70159, Theses scanned by UMI/ProQuest. |
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