Abstracts - Association for Chemoreception Sciences

TGI. The present study investigated the sensation induced by a
thermal stimulation device (six 3mm bars) on the mucocutaneous
surface of the anterior part of the tongue in comparison to a
stimulation on the glabrous skin of the palm. Thermal stimuli
were homogeneous cold (18/18, 20/20, 22/22 and 24/24),
homogeneous warm (36/36, 38/38, 40/40 and 42/42) and mixed
cold and warm bars (TG conditions: 24/36, 22/38, 20/40 and
18/42) temperature (°C±1°C) combinations. Forty subjects
reported their sensation using scales of thermal (cold-warm) and
pain intensities and qualitative descriptors (hot, cold, painful hot,
painful cold, burning, prickling/tingling/stinging). Homogeneous
temperature combinations induced similar sensations on the hand
and on the tongue. In agreement with other studies, a ‘hot’,
‘burning’ sensation associated with higher pain score was reported
for mixed combinations on the hand. The intensity of this TGI
was positively related to the magnitude of temperature difference
between the warm and the cold bars. Interestingly, under the same
TG conditions, sensations induced on the tongue were perceived
as cold and non-painful and described, in some instances, as
‘tingling’. In conclusion, the TG conditions elicited a different
sensation on the tongue and on the hand, most probably due to
variation in thermal spatial sensitivity between these sites.
#P24 POSTER SESSION I: TASTE IMAGING &
PSYCHOPHYSICS; CENTRAL TASTE;
MULTIPLE MODALITIES; CENTRAL &
PERIPHERAL OLFACTION
Flavor Integration of MSG and Citral: Response Time
Measurement
Timothy G. Shepard 1 , Maria G. Veldhuizen 1,2 , Adam Y. Shavit 1,3 ,
Lawrence E. Marks 1,3
1
John B. Pierce Laboratory New Haven, CT, USA,
2
Yale University School of Medicine New Haven, CT, USA,
3
Yale School of Public Health New Haven, CT, USA
Previously, we investigated the integration of gustatory and
retronasal olfactory components of flavorants by measuring
simple response times (RTs) to three oral flavorants: sucrose
(gustatory), citral (olfactory), and their mixture. Responses to
the mixture were faster than values predicted by a model of
probability summation of responses to the separate (independent)
components, suggesting positive coactivation (integration) of
gustatory and olfactory signals in flavor perception (Veldhuizen
et al., Chemical Senses, 2010). In the present experiment, we
tested for evidence of positive coactivation in speeded responses
to a mixture, MSG-citral, that was less pleasant, less familiar, and
less ‘congruent’ than the sucrose-citral mixture previously tested.
Using our computer operated, automated flow system, on each
trial we presented subjects a brief pulse (0.5 sec duration/5 ml
volume) of one of three flavorants (MSG, citral, or their mixture)
or distilled water. Subjects were instructed to press a button as
quickly as possible when they detected any flavor but not respond
to the water. Overall, RTs to the MSG-citral mixture were faster
or equal to the value predicted by probability summation. The
integration of MSG and citral does not appear to be as robust,
however, as the integration of sucrose and citral in the earlier
study. The present findings suggest that familiarity, congruence,
and/or pleasantness with the mixture may influence the degree of
integration of gustatory-olfactory signals during early stages of
flavor processing. Acknowledgements: Supported by NIH grant
R01 DC009021-03 to LEM.
#P25 POSTER SESSION I: TASTE IMAGING &
PSYCHOPHYSICS; CENTRAL TASTE;
MULTIPLE MODALITIES; CENTRAL &
PERIPHERAL OLFACTION
Gustatory-Olfactory Interactions in Favor Perception?
Adam Y. Shavit 1,2 , Timothy G. Shepard 1 , Maria G. Veldhuizen 1,3 ,
Kelly Burger 1 , Lawrence E. Marks 1,2
1
John B. Pierce Laboratory New Haven, CT, USA, 2 Yale School of
Public Health New Haven, CT, USA, 3 Yale University School of
Medicine New Haven, CT, USA
Three experiments examined possible interactions between
gustatory and retronasal olfactory components of flavorants
(sucrose and citral). The first experiment used a two alternative
forced choice method in an unspeeded task to measure the
detection of each flavorant presented in water and in a weak
background of the other flavorant. Results showed the detection
of both sucrose and citral to be largely unaffected by the presence
of a background of the other flavorant. The second experiment
used a single stimulus method in a speeded task to measure
response times (RTs) to discriminate the concentration of sucrose.
Subjects were instructed to identify the sucrose concentration as
weak or strong when it was presented in water and in a
background of citral. (Although we attempted to implement the
complementary experiment, we could not produce discriminable
concentrations of citral because of the small volumes of solute
used in our automated delivery system.) RTs to sucrose were
smaller in the presence of the background, indicating facilitation
(negative masking). The third experiment used a two alternative
forced choice method in an unspeeded task to measure the
discrimination of weak versus strong sucrose in water and in a
background of moderate citral, and the discrimination of weak
versus strong citral in water and in a background of moderate
sucrose. The results showed little effect of the background on
discrimination, although there was a suggestion of masking. The
presence of facilitation (negative masking) in the speeded task but
not in the unspeeded tasks suggests the possibility of distinct early
and late processes in gustatory-olfactory flavor integration.
Acknowledgements: Supported by NIH grant R01 DC009021-03
to LEM.
#P26
POSTER SESSION I: TASTE IMAGING &
PSYCHOPHYSICS; CENTRAL TASTE;
MULTIPLE MODALITIES; CENTRAL &
PERIPHERAL OLFACTION
Taste-odor interactions: Enhancement of odor or taste?
Danielle J Nachtigal 1 , Barry Green 1,2 , Samuel Hammond 3 ,
Juyun Lim 3
1
The John B. Pierce Laboratory New Haven , CT, USA,
2
Yale School of Medicine New Haven, CT, USA, 3 Department of
Food Science and Technology, Oregon State University Corvallis,
OR, USA
Previous studies have reported different types of odor-taste
interactions: some have reported that odors can enhance the
perceived intensity of tastes, and others have reported that tastes
can enhance retronasal odors (or flavors). During informal testing
we observed that the presence of a taste appeared to reduce
adaption to a retronasal odor in a manner consistent with
enhancement of odor by taste. We therefore designed a study to
determine whether enhancement predominates in taste-odor
P O S T E R S
Abstracts are printed as submitted by the author(s)
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