Abstracts - Association for Chemoreception Sciences

#P237 POSTER SESSION V:
HUMAN TASTE PSYCHOPHYSICS;
OLFACTION RECEPTORS; TASTE DEVELOPMENT
Language Determines Whether Taste Sensitivity is Related
to Moral Disgust
Rachel S, Herz
Department of Psychiatry and Human Behavior Providence, RI, USA
The stimuli that trigger emotional disgust are currently debated.
Most contested is whether responses to visceral triggers of
disgust (e.g., cockroaches, disease) are fundamentally the same as
responses elicited by moral transgressions (e.g., lying, cheating).
To address this issue, the present study examined whether: (1)
visceral and moral disgust share a common oral origin (the
rejection of bitter tasting poisons); (2) verbal priming can alter
whether disgust is experienced as a function of taste sensitivity.
102 undergraduates completed a “Behavioral Situations
Questionnaire” developed for the present research which
compared “grossed out” and “angry” to assess three types of
moral transgressions that varied in the degree to which a visceral
disgust dimension was invoked (non-visceral, implied visceral,
directly visceral), and two standard tests of disgust sensitivity.
After completing the questionnaires, taste sensitivity was
assessed with a bitter tasting compound (6-n-propylthiouracil;
PROP). Results showed that the more bitter PROP tasted the
more sensitive a participant was to visceral measures of disgust
sensitivity, but not to moral disgust sensitivity. There were also
no effects for taste sensitivity or type of moral transgression
when “angry” was primed for evaluating the transgressions.
However, when “grossed out” was primed, the more intense
PROP tasted the more “grossed out” participants were by all
transgressions, regardless of their visceral nature. This supports
the proposition that moral and visceral disgust do not share
a common oral origin, but shows that linguistic priming can
transform a moral response into a viscerally repulsive event
and that susceptibility to this priming varies as a function of
an individual’s sensitivity to the origins of visceral disgust—
bitter taste.
#P238 POSTER SESSION V:
HUMAN TASTE PSYCHOPHYSICS;
OLFACTION RECEPTORS; TASTE DEVELOPMENT
Individual differences in the rate of salivary a-amylase
production and its role in the perception of glucose polymers
Trina J. Lapis, Michael H. Penner, Juyun Lim
Oregon State University Corvallis, OR, USA
Our recent data suggest that some humans can consistently
taste glucose polymers, implying possible existence of a glucose
polymer receptor. A potential confound of this idea is that the
hydrolysis byproducts of the glucose polymers, i.e., glucose
and/or maltose, may have, at least to some extent, influenced
taste responsiveness of the tasters. The latter scenario is easily
rationalized due to the catalytic activity of salivary a-amylase.
The present study was designed to investigate (1) individual
differences in the rate of a-amylase production and (2) the
role that it may play in glucose polymer perception. Measured
rate of salivary flow (mg/sec) and a-amylase activity per mg
saliva were used to calculate the rate of a-amylase production
(activity/sec). The same Ss rated the taste intensity of glucose,
sucrose, and glucose polymer solutions (differing in average
chain length) following a sip and spit procedure. Results showed
large individual differences in the rate of a-amylase production
(>30-fold). This can be attributed to the large differences in
salivary flow rate (>18-fold) and a-amylase activity (>30-fold).
Notably, average rates of a-amylase production were similar
between the taster and non-taster groups. Further, within each
group, responsiveness to glucose polymers did not appear to
differ between individuals with high and low rates of a-amylase
production. These findings suggest that salivary a-amylase plays
an insignificant role in glucose polymer perception. Alternatively,
it is possible that the chain lengths of the glucose polymers tested
were too short, i.e., the effect of a-amylase on the hydrolysis was
comparable between high and low a-amylase producers. This
possibility is currently being explored in a follow-up experiment
by using more complex carbohydrates as test stimuli.
#P239 POSTER SESSION V:
HUMAN TASTE PSYCHOPHYSICS;
OLFACTION RECEPTORS; TASTE DEVELOPMENT
Evidence that humans can taste glucose polymers
Juyun Lim, Trina J. Lapis
Oregon State University Corvallis, OR, USA
Previous findings of behavioral and electrophysiological studies
have shown that rodents can taste solutions of Polycose and
further can discriminate the taste of Polycose from that of
sugars. Recent studies have also shown that the T1R2/T1R3
single and double KO mice respond significantly to Polycose.
Based on these data, the possible existence of a glucose polymer
receptor has been proposed. In contrast, it has been assumed
that glucose polymers are tasteless to humans, although it is
known that they evoke a slight odor. During a preliminary study
of the role of salivary a-amylase in the perception of glucose
polymers, some Ss reported that the glucose polymers had
“bread-” or “cereal-like” taste which they could differentiate
from the sweet taste of sugars. The current study was therefore
designed to measure individual differences in taste perception of
various carbohydrates (glucose, sucrose, and glucose polymers
of different chain length) and NaCl. Ss rated taste intensity
of test solutions while their noses were clamped. The results
showed that the perceived intensities of glucose, sucrose, and
NaCl were significantly correlated (r=.68~.80, p