Changes in taste intensity perception following anterior temporal lobe removal in humans

To investigate the role of the anterior temporal lobe in taste perception, we compared taste intensity estimations made by patients who had removal fr om either the left or the right anterior temporal lobe for the treatment of intractable epilepsy with a group of healthy control subjects. Estimations were made for five concentrations of each of four different tastes, as wel l as for five ca rds of varying saturations of gray, which served as a cont rol task. A cross-modal magnitude estimation procedure was employed in whic h subjects used distance on a measuring tape to reflect intensity estimatio n. Distances were then transformed into logs, and the slope and the correla tion with stimulus concentration or saturation was calculated. Correlation was taken as a measure of accuracy of estimation and slope was taken as a m easure of perceived intensity. As predicted, repeated measures analysis of variance (ANOVA) revealed a significant difference between the control grou p and both patient groups in taste intensity estimations, but not for grayn ess, reflecting the importance of the anterior temporal robe in low-level g ustatory but not visual perception. Additionally, repeated measures ANOVA f or slopes indicated that subjects in the right temporal group rated the bit ter taste as more intense than did subjects in other groups, possibly refle cting increased intensity perception of the unpleasant bitter taste.