Herseyblanchard Situational

LEADERSHIP THEORY. See LEADERSHIP, THEORIES OF.

HESS EFFECT. See PERCEPTION (I. GENERAL), THEORIES OF.

HESS IMAGE. See PURKINJE EFFECT/ PHENOMENON/SHIFT.

HEURISTIC THEORY OF PERSUASION. See ATTITUDE AND ATTITUDE CHANGE, THEORIES OF; PERSUASION/ INFLUENCE THEORIES.

HEYMAN'S LAW. See INHIBITION, LAWS OF.

HICK-HYMAN LAW. See HICK'S LAW.

HICK'S LAW. The English physician William Edmund Hick (1912-1974) "reformulated" this principle [it was first described in 1885 by the German physiologist Julius Merkel (1834-1900)], which states that the rate of processing a signal is a linear increasing function of stimulus information (e.g., choice reaction time increases as a linear function of stimulus uncertainty), or that the rate of gain of information is a constant. The time between the occurrence of a stimulus and the initiation of a response is called reaction time (RT). The study of RT represents one of the oldest problems in psychology, dating from 1850 when Hermann von Helmholtz developed the RT experiment. A Hirsch measured the physiological time of the eye, ear, and sense of touch; F. Donders invented the disjunctive RT experiment; S. Exner introduced the term reaction time; Wilhelm Wundt's students began studies of single and complex RTs in 1879; and J. McK. Cattell and his students worked extensively on RT investigations. One of the first experimental studies of the effects of stimulus uncertainty on choice RT was made by Julius Merkel who found a predictable regularity in the nature of RT [cf., Merkel 's law, which is the generalization that to equal differences between stimuli at above-threshold strength, there correspond equal differences in sensation; however, today, this is considered to be an incorrect assumption or generalization]. It was not until many years later, and the advent of information theory, that the general applicability of Merkel's initial finding be-came apparent. W. E. Hick realized that the uncertainty produced by variations in the number of stimulus alternatives could be viewed in information theory terms by expressing the number of alternatives in bits (i.e., "binary digit" where a bit is the amount of information needed to reduce the alternatives in a choice situation by one half). Hick found that RT increases as a linear function of the log (base 2) of the number of stimulus alternatives and, thus, in information theory terms, RT is proportional to stimulus uncertainty. Hick's discovery was not in itself new but was a confirmation of Merkel's earlier finding in 1885, using a different scale for describing the number of stimulus alternatives. Hick's approach makes it possible to map a number of ways to manipulate stimulus uncertainty onto a common scale. Although there is some disagreement, the general trend of the data seems to indicate that choice RT is proportional to stimulus information (cf., symbolic distance effect - when a participant has to gauge from memory the relative posi tion of two items on a dimension - such as length - the smaller the difference between the two items on the dimension, the longer is the participant's RT). Within limits, it does not seem to matter if uncertainty is manipulated through variations in the number of stimulus alternatives or through variations in stimuli probabilities or their sequential dependencies. A variation of Hick's law, called the Hick-Hyman law - named after W. E. Hick and the American psychologist Ray Hyman (1928- ), is the generalization that RT increases as a function of the amount of information transmitted in making a response. Apparently, Hick's law possesses generality because it applies to vigilance tasks as well as to the choice RT tasks for which it was originally formulated. See also DONDERS' LAW; FECHNER'S LAW; FITTS' LAW; INFORMATION AND INFORMATION-PROCESSING THEORY; REACTION-TIME PARADIGMS/MODELS; SYSTEMS THEORY. VIGILANCE, THEORIES OF. REFERENCES

Hirsch, A. (1861-1865). Experiences chrono-scopiques sur la vitesse des differentes sensations et de la transmission nerveuse. Societe Science National Bulletin, 6, 100-114. Donders, F. (1868). Die schnelligkeit psychischer processe. Archiv fur Anatomie und Physiologie, 2, 657-681. Exner, S. (1873). Experimentelle untersuchung der einfachsten psychischen processe. Pflugers Archiv Gesamte Physiologie, 7, 601-660. Merkel, J. (1885). Die zeitlichen verhaltnisse der willensthatigkeit. Philosophische Studien, 2, 73-127. Cattell, J. McK. (1886a). Psychometrische untersuchungen. Philosophische Studien, 3, 305-335, 452-492. Cattell, J. McK. (1886b). The time taken up by the cerebral operations, Mind, 11, 220-242, 377-392, 524-538. Hick, W. E. (1952). On the rate of gain of information. Quarterly Journal of Experimental Psychology, 4, 11-26. Hyman, R. (1953). Stimulus information as a determinant of reaction time. Journal of Experimental Psychology, 45, 188-196.

Garner, W. (1962). Uncertainty and structure as psychological concepts. New York: Wiley. Kornblum, S. (1968). Serial-choice reaction time: Inadequacies of the information hypothesis. Science, 159, 432434.

Smith, E. (1968). Choice reaction time: An analysis of the major theoretical positions. Psychological Bulletin, 69, 77-110.

Alluisi, E. (1970). Information and uncertainty: The metrics of communications. In K. DeGreene (Ed.), Systems psychology. New York: McGraw-Hill.

Teichner, W., & Krebs, M. (1974). Laws of visual choice reaction time. Psychological Review, 81, 75-98.

HIERARCHICAL ASSOCIATIONS THEORY. See ESTES' STIMULUS SAMPLING THEORY.

How To Win Your War Against Anxiety Disorders

How To Win Your War Against Anxiety Disorders

Tips And Tricks For Relieving Anxiety... Fast Everyone feels anxious sometimes. Whether work is getting to us or we're simply having hard time managing all that we have to do, we can feel overwhelmed and worried that we might not be able to manage it all. When these feelings hit, we don't have to suffer. By taking some simple steps, you can begin to create a calmer attitude, one that not only helps you feel better, but one that allows you the chance to make better decisions about what you need to do next.

Get My Free Ebook


Post a comment