Psychophysics, animal

Acids eliciting similar responses are thus, on average, closer than those giving dissimilar responses which are at the opposite ends of the space. Clearly the distances between alanine (A) and B-arginine (B) are markedly altered upon changing concentration. The conclusion is that response similarities measured at one concentration do not necessarily predict those existing at other concentrations. A similar conclusion was reached on the basis of animal psychophysical studies (24). 

Prior to 1960, the conventional wisdom in the textbooks was that humans and only a few other animals could see in color. This changed rapidly beginning at that time as a flurry of laboratory activity showed that nearly all animals had multiple channels of spectral sensitivity137. It then became popular to discuss whether the animals with such sensitivity actually processed the collected data in order to perceive color. The laboratory explorations of this subject, primarily psychophysical, were frequently hampered by the indifference of the animal to the investigators desires. Cats in particular were felt to not see in color while in fact they did not want to actively participate in the experiments. 

Animals can be trained to report reliably and in great detail about their sensory perception. This is accomplished through psychophysical techniques that is, sensory function is determined by behavioral means. Such methodology is appropriate for determination of no-effect levels and for detailed... 

Over the past two decades scientists in many disciplines have become increasingly interested in mechanisms of smell. Researchers from physics, chemistry, biology, psychophysics, and animal behavior have focused their attention on the relation between behavior and chemical structure, each using the techniques of his or her discipline. We still lack an understanding of why chemicals smell the way they do. However, with refined methods of physical and sensory measurement, researchers are beginning to ask the proper questions. 

The present Interest in the characterization of both animal and human secretions has paralleled the development in psychophysical measurement techniques and in analytical methods such as headspace concentration, gas chromatography, and the combination of gas chromatography/mass spectrometry (GC/MS) which have made it possible to routinely separate and identify submicrogram quantities of organic compounds. GC/MS profiling of the small organic compounds present in body secretions, such as blood serum, cerebrospinal fluid, and urine of diseased and healthy individuals, has provided useful diagnostic information (2). 

Recent evidence suggests that the oral detection of fatty acids such as stearic acid do occur in the human and rodent oral cavity, and stimulate a fatty acid taste response. Both animal and human studies indicate that stearic acid elicits a small to moderate taste response in the oral cavity. The hedonic appeal of fats may be enhanced especially when consumed with carbohydrates. Future studies will determine whether long-chain fatty acids such as stearic acid or linoleic acid represent a primary taste stimulus in the human oral cavity. Finally, improved dehvery methods for saturated and unsaturated fatty acids for psychophysical studies will stimulate the advancement of this important field of study. 

Circadian Rhythm Cycle of roughly twenty-four hours in behavioral, psychophysical, biochemical, and physiological processes in humans as well as in other animals, fungi, plants, and certain forms of bacteria. 

---