SPATIAL SUMMATION IN THE WARMTH SENSE

The warmth sense is characterized by generous spatial summation: perceived strength of warmth sensation increases with increasing areal extent of stimulation as well as with increasing stimulus intensity. When intensity is low, area exerts its greatest effect, in that warmth depends on the product of stimulus area and intensity - i.e., on total power in watts. Response to integrated heat input at low intensity enables the warmth sense to help maintain constant body temperature. As stimulus intensity increases, area’s relative influence on warmth diminishes until the pain threshold is reached, whereupon spatial summation vanishes. Lack of summation at high intensity enables the warmth sense to help protect the skin from potentially damaging heat. The level-dependence of spatial summation is reflected in the way stimulus size influences the psychophysical power functions that relate warmth sensation to stimulus intensity: the larger the areal extent of the stimulus, the smaller the exponent of the power function.

[1]  L. Marks,et al.  Thermally induced pain, the Dol scale, and the psychophysical power law. , 1968, The American journal of psychology.

[2]  Spatial summation of pain. , 1958, Journal of applied physiology.

[3]  D. Kenshalo,et al.  Spatial summation on the forehead, forearm, and back produced by radiant and conducted heat. , 1967, Journal of comparative and physiological psychology.

[4]  W. Banks.  Reaction time as a measure of summation of warmth , 1973 .

[5]  Lawrence E. Marks,et al.  Spatial summation and the dynamics of warmth sensation , 1971 .

[6]  J D Hardy,et al.  STUDIES IN TEMPERATURE SENSATION. III. THE SENSITIVITY OF THE BODY TO HEAT AND THE SPATIAL SUMMATION OF THE END ORGAN RESPONSES. , 1937, The Journal of clinical investigation.

[7]  J. Hardy.  The nature of pain. , 1956, Journal of chronic diseases.

[8]  J. Craig.  Vibrotactile loudness addition , 1966 .

[9]  S. S. Stevens.  The direct estimation of sensory magnitudes-loudness. , 1956, The American journal of psychology.

[10]  D. Murgatroyd.  SPATIAL SUMMATION OF PAIN FOR LARGE BODY AREAS , 1964 .

[11]  W S Cain,et al.  Spatial discrimination of cutaneous warmth. , 1973, The American journal of psychology.

[12]  H. Barlow,et al.  Change of organization in the receptive fields of the cat's retina during dark adaptation , 1957, The Journal of physiology.

[13]  S. S. Stevens.  On the psychophysical law. , 1957, Psychological review.

[14]  J. C. Stevens,et al.  Families of Converging Power Functions in Psychophysics , 1974 .

[15]  Lawrence E. Marks,et al.  Sensory Processes: The new Psychophysics , 1975 .

[16]  L E Marks,et al.  Spatial summation of warmth: influence of duration and configuration of the stimulus. , 1973, The American journal of psychology.