Method of stimulation, mouth movements, concentration, and viscosity: Effects on the degree of taste adaptation

Abstract

Although sensory adaptation, the gradual loss of sensation during prolonged stimulation, has been demonstrated in laboratory taste experiments, a comparable loss of taste intensity is not experienced in real-life eating situations. This discrepancy may be due to differences in the proximal stimuli or to differences in the ways the taste receptors are stimulated. In two experiments, the effects of four potentially relevant variables were investigated: stimulus intensity, stimulus viscosity,mouth movements, and presentation method. During the initial seconds of stimulation, adaptation to the weakest of the two solutions was faster. Although more viscous stimuli were less sweet, viscosity as such did not affect adaptation rate, nor did mouth movements. Among the three presentation methods, a sucrosesoaked filter paper on the tongue produced more adaptation than either sipping the solution or flowingit over the tongue. This suggests that even mouth movements far more subtle than those still present in the no-movement condition of a sip-and-spit experiment can disrupt the adaptation process.

Influence of wearing an unstable shoe on thigh and leg muscle activity and venous response in upright standing

“…This design recreates natural uneven walking surfaces to reduce problems caused by today's rigid soled shoes and hard ground. The adaptation of the human biological system for movement control (Ferrel, Leifflen et al, 2000) includes changes in the response of neural receptors (Theunissen, Kroeze et al, 2000) and changes in the function of central and autonomous nervous systems (LeBlanc, Dulac et al, 1975;Pia, 1985). Exercises repeated daily or weekly can improve postural control (Hu & Woollacott, 1994) and generate structural and functional adaptations in the neuromuscular system (Hakkinen, Kallinen et al, 1996).…”

Postural control adaptation during galvanic vestibular and vibratory proprioceptive stimulation

“…2). Parallel adaptive processes related to specific components in the chemical or biological environment might be common in many biological systems [38], [39]. Thus, the procedures employed in this study to describe postural adaptation could rather easily be applied to other kinds of adaptive processes in various biological and biomechanical systems.…”

Taste adaptation during the eating of sweetened yogurt

“…As these measures were obtained from the same individuals we can relate the individual adaptation data from Experiments 1 and 2. There are substantial individual differences in the degree of adaptation to a filter paper (Meiselman and Buffington, 1980;Theunissen et al, 1999). We expect that subjects with little adaptation in the filter paper condition show a low degree of adaptation with yogurt as well.…”

“…For instance, saliva secretion dilutes the stimulus and thus may decrease perceived taste intensity (O'Mahony & Wong, 1989). In addition, the mouth movements that subjects make during eating may cause recovery from adaptation (Theunissen et al, 1999). Second, in the yogurt condition a complex mixture was judged, whereas in the filter paper condition sucrose and citric acid were offered separately.…”