The human brain is supposed to have a capacity for supramodal evaluation of information-interaction from several senses (often studied through fMRI). Gunnar Borg’s Range Model is a theoretical framework for interindividual, intermodal and interdisciplinary comparisons. The model postulates that the total natural subjective dynamic range from zero (or the threshold) to maximum (or a terminal level very close to the maximal intensity) is approximately subjectively equal for all individuals. Each individual experience is thus interpreted in relation to its position in the individual range, regardless of the size of the physical stimulus range. For interindividual and intermodal comparisons it is also important to have a good reference, a firmly schematized conception, with high interindividual agreement. A maximal perceived exertion has been found to work well for this purpose. Perceived exertion is an emergent modality consisting of many symptoms and cues with several sensory systems involved in conveying information to the brain from the muscles, respiration, skin, joints etc.; and with several important physiological correlates (e.g., heart rate, blood lactate, ventilation, skin temperature). In contrast to many other modalities, the perception of exertion comes from an active interaction of the body with the environment and the person usually regulates performance as a response to the perception. For healthy people it is also not harmful with a maximal exertion. Thus, a maximal perceived exertion is something most of us have experienced. In a questionnaire study the idea was investigated that, at least in some cases, what schematized conception is used will have importance. This should for example be true for modalities where individual experiences vary greatly, as, e.g., for pain. Modalities included were taste (sourness and sweetness), heaviness, loudness, brightness, fear, smell, and pain. Two groups of 20 persons (10 men and 10 women) followed one of two instructions. Group A compared each item with their conception of a maximal heaviness (as “100”) and Group B used item-specific (intramodal) references of "sourest, sweetest, loudest, etc., imaginable". The cross-modal task of comparing different modalities to the conception of a maximal heaviness worked well. As expected there was a significant difference between the two kinds of instructions for pain (with a lower mean value for group B, p < 0,001), but, and more importantly, also a larger variance for group B. For most modalities, except for pain, the intramodal references (sourest, sweetest, loudest, etc.) may thus be conceived of as similar across individuals as well as approximately equal to the reference of a maximal heaviness, or at least was used that way. For a modality, such as pain, where individual experiences may differ extensively, the cross-modal task of using the conception of a maximal heaviness should be preferred.
Lund: International Society for Psychophysics , 2014. 7-7 p.