Psychophysical studies

Doty, R.L. (1977) A review of recent psychophysical studies examining the possibility of chemical communication of sex and reproductive status in humans. In Muller-Schwarz D and Mozell, M.M., Chemical Signals in Vertebrates. Plenum, New York, pp. 273-286. 

Much of the ziziphin chemistry was carried out by Dr. Frank Koehn, and psychophysical studies were performed by Drs. Claire Murphy and... 

Two areas of research, psychophysics and sensory evaluation, have made recent contributions to the understanding of oral sensations of heat derived from peppers. Psychophysical studies have characterized observer s responses to heat from spice-derived compounds, focussing on such aspects as time-intensity functions, areas of oral stimulation, correlation with evoked salivary flow, interactions with basic tastes, and effects of sequential stimulation. Sensory evaluation of the heat level of ground red pepper has recently been advanced by the validation of a new method which solves many of the problems inherent in the previous Scoville procedure. The new method is based on anchored graphic rating by panels Who are trained with physical reference standards. The procedure has shown excellent reliability, fine discriminations among samples, and high correlations with instrumental determinations of capsaicinoid content of pepper samples. 

Since a series of several stimuli are usually presented to subjects in psychophysical studies, the opportunity arises to study effects of sequential stimulation. These effects can have practical implications such as the number of stimuli which may be sampled in applied sensory evaluation without fatigue. During the time-intensity ratings Which produced the data in Figures 2 and 3, stimuli were presented in different orders, with the first and third concentrations in the series of each compound presented either before or after the stimulus of next higher concentration. 

Wood, F. W. 1968. Psychophysical studies on the consistency of liquid foods, S.C.I. Monograph Rheology and Texture ofFoodstiffss, pp. 40-49, Society of Chemical Industry, London. 

Attal N, Gaude V, Brasseur L, Dupuy M, Guirimand F, Parker F, Bouhassira D. Intravenous lidocaine in central pain a double-bhnd, placebo-controUed, psychophysical study. Neurology 2000 54(3) 564-74. 

LaMotte RH, Shain CN, Simone DA, Tsai EF (1991) Neurogenic hyperalgesia psychophysical studies of underlying mechanisms. J Neurophysiol 66 190-211... 

Wood, F.W. "Psychophysical Studies on the Consistency of Liquid foods" SCI Monograph No. 27, Society of Chemical Industry, London, 1968 p. 40. 

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). 

Humans detect at least five primary taste stimuli, which include sweet, sour, salty, bitter, and umcmi taste. Representative taste stimuli for the five primary taste qualities consist of polar molecules that are generally presented as aqueous solutions to subjects for psychophysical studies. Medium- and long-chain fatty acids are non-polar molecules that do not readily dissolve in... 

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. 

There is a wealth of experimental evidence gained from psychophysical studies on humans (e.g. Duchowski, 2002) desalbing the way in which we scan a visual scene. Our eyes are controlled by series of short, fast movements known as saccades. These can be reflex actions derived from a stimulus in the field of view (bottom up) or guided by a conscious (or unconscious) desire to search a particular part of the field of view (top down). Part of the reason for saccadic eye motion is that mammalian eyes do not have even visual acuity across the whole field of view. In fact, the central part of the light-sensitive retina (the fovea) has the highest resolution. So, an entire microscope field of view, for example, can be seen by a series of search-based saccades that direct the eyes towards attractors in the scene. Reflex eye movements tend toward colour and high-contrast areas of the visual field. 

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