On the theory of behavioral mechanics.

The Theory of Behavioral Mechanics is the behavioral analogue of Newton's laws of motion, with the rate of responding in operant conditioning corresponding to physical velocity. In an earlier work, the basic relation between rate of responding and sessions under two FI schedules and over a range of commonly used session values had been shown to be a power function. Using that basic relation, functions for behavioral acceleration, mass, and momentum are derived here. Data from other laboratories also support the applicability of a power function to VI schedules. A particular numerical value is introduced here to be the standard reference value for the behavioral force under the VI-60-s schedule. This reference allows numerical values to be calculated for the behavioral mass and momentum of individual animals. A comparison of the numerical values of the momenta of two animals can be used to evaluate their relative resistances to change, e.g., to extinction, which is itself viewed as a continuously changing behavioral force being imposed on the animal. This overall numerical approach allows behavioral force-values to be assigned to various experimental conditions such as the evaluation of the behavioral force of a medication dosage.

Power spectral density analysis of lateral human standing sway.

A number of investigators have used power spectral density (PSD) analysis to try to identify and quantify various sensory systems which are involved in upright standing. Using PSD analysis, over a frequency range from 0.02-2.5 Hz, the present study examined two trials of lateral sway in each of 80 men. The results showed that little change occurred in PSD values between the first and second trials. Exponential curves were fit to the averaged trials data of each subject. The values of the parameter estimates obtained from the curve-fitting were regressed on the values of various direct, and derived anthropometric variables to try to explain the variance of the parameter estimates in terms of the anthropometrics. The subject's center of gravity location accounted for no more than 15.8% of the parameter variance, whereas the remaining anthropometrics explained even less. The overall averaged data suggest that three functions (related to visual, vestibular, and proprioceptive processes) may underlie the sway pattern over this frequency range. PSD curves of individuals with a history of high-level athletic activity clearly differed from those of sedentary subjects.

Psychophysical Relationship between Sweetness and Redness in Strawberry-Flavored Drinks.

A consumer-like taste panel of 10 men and women, ages 22-50, evaluated the sweetness, pleasantness and color acceptability of five sweetened, strawberry-red colored beverages, containing 3.2% to 4.8% sucrose, using magnitude estimation. Five intensities of strawberry colors were formulated using increasing volumes of FD&C Red 40 and a constant volume of both FD&C Yellow 6 and imitation strawberry flavoring. Color measurements from the Gardner XL-23 colorimeter and the G. E. Recording Spectrophotometer were converted to L*, a*, b*. Sensory responses were evaluated against the value arctan (a*/b*), representing color intensity, and sucrose concentration, as percent sugar. Sweetness perception increased with increasing sucrose concentration, producing a slope greater than 2.00 (r2≥0.87) but produced an exponent less than 1.0 (r2<0.91) when evaluated against arctan (a*/b*). Sweetness increased approximately 2 to 12% with increasing color intensity in 4% sucrose solutions. Perceived sweetness was influenced by pleasantness effects and color acceptability. Color 3 samples were rated as the sweetest, most pleasant-tasting drinks and had the most acceptable color. The color-sweetness function was linear over a narrow color range.

Psychophysical Relationships Between Perceived Sweetness and Color in Cherry-Flavored Beverages.

Sweetness of cherry-flavored and colored beverages, containing 3.2 to 4.8% sucrose, was quantified by a panel of 10 men and women, ages 22-50, using magnitude estimation. Five intensities of cherry colors were formulated using increasing volumes of Red 40 and a constant volume of both Blue 1 and imitation cherry flavoring. Color measurements from the Gardner XL-23 Colorimeter and the G. E. Recording Spectrophotometer were converted to L*, a* and b*. Sweetness was evaluated against sucrose concentration and arctan (a*/b*). Magnitude tests to evaluate color acceptability and pleasantness were also conducted. All magnitude estimates were normalized and subjected to a two-way ANOVA. Sweetness perception was highly correlated with increasing sucrose concentration (r2> .90), producing a power function exponent of 1.98. Sweetness increased approximately 3 to 13% with increasing color intensity in solutions containing 3.96 to 4.4% sucrose. The exponent describing the sweetness-color relationship was less than 1.0, and followed the power law over a narrow range of color intensities. Color 4 was the most acceptable color and color 3 containing 4.6% sucrose had the most pleasant taste. Color might be used to replace some sucrose and can optimize pleasurable taste sensations.

The effect of signal probability, food intake, sex, and smoking on gustation, as measured by the theory of signal detection.

The possibility of applying Signal Detection Theory (SDT) to gustation was investigated by testing the effect of three variables--smoking, signal probability, and food intake (confounded with time of day)--on the taste sensitivity to sucrose of 24 male and 24 female Ss. No main effects or interactions were significant. The study indicated a "warm-up" effect, while adaptation was questionable. An analysis of false alarm (FA) reports was undertaken and discussed. Correlations were obtained between numerous variables and sensitivity. None of the correlations was statistically significant. It was concluded that although SDT is theoretically applicable to the gustatory modality, it is not practical for large-scale research.