1.
Perception of oral food breakdown. The concept of sensory trajectory.
Lenfant, F, Loret, C, Pineau, N, Hartmann, C, Martin, N
Appetite. 2009;(3):659-667
Abstract
Texture perceived in mouth largely depends on the behaviour of the food when it is broken down and transformed by the mouth elements. Texture results from a dynamic process in which texture attributes are continuously analysed by the oral sensory systems during mastication. However, the particular sequence of perceptual events that occur during oral food breakdown remains unknown. The aim of the present study is to describe the succession of perceptual events that happen in mouth during mastication and to show that for each food a texture pathway can be built. This for, we used a sensory method enabling to evaluate the dynamics of texture perceptions during food consumption: the Temporal Dominance of Sensation. On different breakfast cereals, we measured the sensation dominating at each point of the mastication process. We showed that the dynamics of appearance and disappearance of each texture sensation experienced in mouth during the eating process differed among cereals. However, some common features in this sensory trajectory were also observed for the category of products studied. Hardness, crackliness and crispness were rather perceived at the beginning of the mastication period, brittleness and lightness in the middle and stickiness at the end.
2.
Oral perception of bolus in healthy young women.
Miyaoka, S, Ashida, I, Miyaoka, Y
Perceptual and motor skills. 2008;(3):870-80
Abstract
This study was designed to characterize oral perception of both weight and volume of boluses. A total of 80 healthy young female subjects was recruited and divided into bolus weight (n = 40) and bolus volume (n = 40) conditions. Tap water (25 degrees C) was the experimental material, and seven reference stimulus amounts ranging from 10 to 40 (grams and mL) were prepared. The reference stimuli, including a modulus of 20 (grams and mL), were delivered to the subjects in randomized order. The estimated magnitudes (psi) conformed to both the Fechner's and Stevens' psychophysical laws by the following equations: (1) psi(W) = 314.3 log (S+1) - 300.2 where S is stimulus intensity or weight, and psi(V) = 249.7 log (S+1) - 222.3 (volume) on logarithmic (log)-linear scales, and (2) psi(W) = 1.908 S1.297 and psi(V) = 4.097 S1.032 on log-log scales, respectively. The results indicate that oral perception of bolus weight and bolus volume conforms to the representative psychophysical laws.
3.
Odor-induced changes in taste perception.
Djordjevic, J, Zatorre, RJ, Jones-Gotman, M
Experimental brain research. 2004;(3):405-8
Abstract
We investigated odor-induced changes in taste perception (OICTP), by examining the influence of strawberry and soy sauce odors on perceived sweetness (Experiment 1) and saltiness (Experiment 2). We explored whether taste-smell interactions occur at the central level, by delivering odorants (strawberry, soy sauce, odorless water) and tastants (sucrose, sodium chloride) separately, and whether effects of imagined odors are comparable to those of physically presented odors. We found specific taste-smell interactions: sweetness enhancement induced by strawberry odor and saltiness enhancement induced by soy sauce odor. These interactions were elicited with separate delivery of olfactory and gustatory stimuli. Secondly, we found a similar but rather limited effect with the imagined odors: imagined strawberry enhanced perceived sweetness of water solutions, and imagined soy sauce enhanced perceived saltiness of weak sodium chloride solutions. We concluded that OICTP is a centrally mediated phenomenon, and that imagined odors can to some extent induce changes in perceived taste intensity comparable to those elicited by perceived odors.
4.
Heart rate-perceived exertion relationship during training and taper.
Martin, DT, Andersen, MB
The Journal of sports medicine and physical fitness. 2000;(3):201-8
Abstract
BACKGROUND Examine the heart rate-perceived exertion (HR-RPE) relationship under conditions of high-intensity training and taper. METHODS Experimental design and participants: prospective with collegiate cyclists (n=11) completed six weeks of high-intensity interval training, followed by a one-week taper. INTERVENTIONS participants completed a high-intensity training regimen along with graded exercise tests (GXT) throughout the training and the taper. MEASURES heart rates (HR) and ratings of perceived exertion (RPE) were recorded following each stage of the GXTs. Scores on GXTs were also recorded. RESULTS . The HR-RPE relationship during GXTs changed over the course of the training with greater RPEs for a given HR at the end of the training compared to the beginning. The most powerful predictors of the performance response to the taper were training induced changes in the HR-RPE relationship and decreases in HR for a given power output. Those individuals who reported higher RPEs for lower HRs were more likely to have better performance responses to taper (r=0.72) as were those who had larger changes in the HR-power output relationship (r=0.76). CONCLUSIONS These results indicate that changes in the HR-RPE relationship during high-intensity training may be used to monitor the magnitude of overreaching that is necessary for a positive response to a taper. For coaches and athletes, the HR-RPE ratio may be a practical measure for monitoring an aspect of fatigue associated with high-intensity training.