1 1 Symposium Chemosensory Receptors Satellite DEVELOPMENT ...

501 Poster Developmental, Neurogenesis, and ConsumerResearchPLEASANTNESS INFORMATION FACILITATES DETECTIONIN TASTEVeldhuizen M.G. 1 , Meggelen Van C. 1 , Kroeze J.H. 2 1 PsychologicalLaboratory, Utrecht University, Utrecht, Netherlands; 2 WageningenTaste and Smell Center, Wageningen University and Research Center,Wageningen, NetherlandsAffective context has been shown to influence performance on anumber of tasks in several sensory modalities. It is not known whetheraffective context is able to influence perceptual processing in taste. Intwo experiments we investigated a special cross-modal top-downexample of affective priming, namely detection of taste targets precededby visually presented words containing pleasantness information. In thefirst experiment with long prime presentation times (1000 ms) and longprime-target intervals (750-1000 ms) we found that detection times ofgustatory target stimuli are shortened if the pleasantness information inthe prime is congruent with hedonic tone of the taste stimulus (e.g.“good”-sucrose; “bad”-caffeine; “neutral”-demineralised water) ascompared to incongruent prime-target combinations (F (1,14) = 5.253, p =0.038). In the second experiment using shorter prime presentation times(200 ms), this facilitation of detection by an affectively congruentcontext was replicated (F (2,24) = 8.787, p = 0.001). In the firstexperiment congruency facilitation was most prominent for sucrose, inthe second experiment for caffeine. This finding supports the idea ofpreferential facilitation of the processing of negative stimuli under timeconstraints.Without time-constraints positive stimuli might benefitmost from congruency facilitation. This is in line with findings in theperceptual-defense literature, claiming that the defense against negativestimuli demand extra attentional resources leading to a delay ofresponse.503 Poster Developmental, Neurogenesis, and ConsumerResearchIDENTIFICATION OF LATENT VARIABLES IN A SEMANTICODOR PROFILE DATABASE USING PRINCIPALCOMPONENT ANALYSISZarzo M. 1 , Stanton D. 2 1 Procter & Gamble, Cincinnati, OH;2 Corporate Modeling and Simulations, Procter & Gamble, Cincinnati,OHMany classifications of odors have been proposed, but none of themhas yet gained wide acceptance. Odor sensation is usually described bymeans of odor character descriptors. If these semantic profiles areobtained for a large diversity of compounds, the resulting database canbe considered representative of odor perception space. Few of thesecomprehensive databases are publicly available, being a valuable sourceof information for fragrance research. Their statistical analysis hasrevealed that the underlying structure of odor space is highlydimensional, not governed by a few primary odors. In a new effort tostudy the underlying sensory dimensions of the multivariate olfactoryperception space, we have applied Principal Component Analysis to adatabase of 881 perfume materials with semantic profiles comprising 82odor descriptors. The relationships identified between the descriptorsare consistent with those reported in similar studies, and have allowedtheir classification into 15 groups. This work has been funded by apostdoctoral grant sponsored by the Fulbright Program and the SpanishMinistry of Education and Science.502 Poster Developmental, Neurogenesis, and ConsumerResearchCORRELATION BETWEEN BRAIN ACTIVITY AND ONLINEPSYCHOPHYSICAL MEASUREMENT: HOW THEEVALUATIVE TASK AFFECTS BRAIN ACTIVATIONCerf-Ducastel B. 1 , Haase L.B. 1 , Kemmotsu N. 1 , Jacobson A. 1 , Green E. 1 ,Murphy C. 1 1 Psychology, San Diego State University, San Diego, CAWe used event related fMRI (3T GE) to investigate corticalactivations related to taste. Subjects performed two separate runs. Inone, they evaluated the pleasantness of the simuli, in the other, theirintensity, while stimuli were presented to the mouth as 0.3 ml ofsolution in 1 s boluses alternating with water. An important questionrelated to this type of paradigm is whether the cognitive task, i.e.evaluating intensity or pleasantness, affects the perception of thestimuli. To investigate this question, we compared the level ofcorrelation between the psychophysical measures of intensity ofpleasantness and the brain activity in both cognitive tasks, in 4 regionsof interest, amygdala, orbitofrontal cortex BA13, BA47 and insula.Image analysis was conducted using AFNI (Cox, 1996). Results showedthat for sucrose, saccharin, citric acid and caffeine, pleasantness ratingswere significantly more strongly correlated with brain activity whensubjects evaluated pleasantness than when subjects evaluated intensity(p = 0.039); there was a similar effect for intensity ratings thatapproached significance (p = 0.057) with intensity ratings more stronglycorrelated with brain activity when subjects evaluated intensity.Interestingly, 2 of the 6 stimuli, GMP and NaCl showed oppositeeffects. Although the interpretation of this observation is still unclear, itreinforces the importance of sampling a wide range of stimuli in orderto understand the complex mechanisms at play in gustatory function.Supported by NIH grant numbers R01AG04085 to CM andR03DC051234 to BCD.126