|MadSci Network: Neuroscience|
Technically, your friend is right because this doesn't have anything to do with touch, smell, hearing or sight affecting taste. But you're right that it is an interaction in the nervous system -- an interaction with stress.
I looked up "stress" and "taste" on everybody's friend, www.pubmed.gov, and found 3 abstracts: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=9700013&query_hl=3&itool=pubmed_docsum
Different people react in different ways to stress, and not always the same way each time. In some people, stress suppresses the appetite. Food tastes the same to me when I'm stressed, but either I find my stomach turns at the thought of food, or I begin craving comfort foods.
The bitter with the sweet: the taste/stress/temperament nexus.
* Dess NK, Edelheit D.
Department of Psychology, Occidental College, Los Angeles, CA 90041, USA.
Is the tongue a window to the psyche? In rats, stress alters taste, and individual differences in taste are related to measures of emotion. The present study concerned stress-induced changes in taste and its modulation by temperament in people. College students rated saccharin's bitterness and sweetness and a tone's loudness after exposure to a mild stressor. Temperament (trait arousability, pleasure, and dominance) was assessed separately. When individual differences were ignored, stress appeared to selectively increase sensitivity to saccharin's bitterness. However, the stressor's impact was modulated by temperament: Stress nonselectively augmented stimulus magnitude ratings among highly arousable individuals; relative to high-pleasure counterparts, low-pleasure individuals gave higher bitterness ratings and lower sweetness ratings after stress. Taste does seem to provide a glimpse of the emotional life of humans and other animals and opens new avenues to the study of the biological bases of affect.
Changes in taste perception following mental or physical stress. * Nakagawa M, Mizuma K, Inui T.
Suntory Ltd, Institute for Fundamental Research, Osaka, Japan.
Taste perception depends not only on the chemical and physical properties of tastants, but may also depend on the physiological and psychological conditions of those who do the tasting. In this study, the effects of mood state on taste sensitivity was evaluated in humans who were exposed to conditions of mental or physical fatigue and tension. Taste responses to quinine sulfate (bitter), citric acid (sour) and sucrose (sweet) were tested. The intensity of the taste sensations were recorded by a computerized time-intensity (Tl) on-line system. Subjects performed mental tasks by personal computer or physical tasks by ergometer for 10-40 min. Before and after these sessions, the duration of the after-taste and the intensity of the sensation of taste were recorded by the Tl system, and in addition, psychological mood states were evaluated with POMS (Profile of Mood State). Tl evaluation showed that after the mental tasks, the perceived duration of bitter, sour and sweet taste sensations was shortened relative to the control. Total amount of bitterness, sourness and sweetness was also significantly reduced. Furthermore, the maximum intensity of bitterness was significantly reduced. There were no significant differences in bitterness and sweetness sensations following physical tasks. However, relative to before the physical task, the duration of the after-taste of sourness was significantly shortened by the physical task. After the physical task, the buffering capacity of saliva was significantly increased. Thus mental and physical tasks alter taste perception in different ways; the mechanisms underlying these changes remain to be determined.
PMID: 8670698 [PubMed - indexed for MEDLINE]
Human taste contrast and self-reported measures of anxiety. * Specht SM, Twining RC.
Department of Psychology, Lebanon Valley College, Garber Science Center, Annville, PA 17003-0501, USA.
Successive negative taste contrast in humans was demonstrated with a common taste stimulus, i.e., cherry-flavored Kool-Aid. A total of 31 male and female college-aged participants rated a 7% sucrose solution which was cherry-flavored as less sweet when it was preceded by a 28% rather than a 7% sucrose solution which was cherry-flavored. Because drugs such as the benzodiazepines affect taste contrast in rats and act as anxiolytics in humans, the present experiment also examined whether several self-reported measures of anxiety were related to taste contrast in humans. Neither scores on Taylor's Manifest Anxiety Survey nor those on the State-Trait Anxiety Inventory were related to "sweetness" ratings or contrast effects.
PMID: 10483624 [PubMed - indexed for MEDLINE]
Try the links in the MadSci Library for more information on Neuroscience.