The judgment of very weak sensory stimuli : with special reference to the absolute threshold of sensation for common salt / by Warner Brown.

  • Brown, Warner, 1882-1956.
Date:
1914
Catalogue details

Licence: In copyright

Credit: The judgment of very weak sensory stimuli : with special reference to the absolute threshold of sensation for common salt / by Warner Brown. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The three figures represent the work of three of the four observers in one of Camerer's experiments (Ztsch. f. Biol., vol. 21 (1885), p. 578). The intensity of the salt solution is measured off to scale along the horizontal base line. The unit solution is 0.0159 per cent, so that “6” means 6 times 0.0159 per cent, or 0.0954 per cent. The first stimulus is water (0), then comes a solution of one-eighth of the unit, then one of one-quarter of the unit, then one of one-half the unit; then of one, one- and-a-half, two, three, four, and six times the unit strength. The height of the solid line represents the percentage of positive judgments out of a possible 50 for each solution. The height of the outlined portion represents one-half of the number of doubtful cases, also reduced to per cent. [268]