294 Action Selection
texts. The view of many cognitive psychologists seems to be
that input and central processes can be investigated without
one’s having to be concerned with the translation of the out-
come of these processes into output. This view is ironic,
given that a major impetus to the rise of contemporary cogni-
tive psychology was research on human performance con-
ducted by Paul Fitts (see Fitts & Posner, 1967), Donald
Broadbent (1958), and others in the 1950s. Outside of the
United States, more recognition has been given to the impor-
tance of selection and execution of action in human informa-
tion processing. Action selection is seen as fundamental
because it involves the interface between perception and ac-
tion. It is the theme of this chapter that action selection is of
vital importance to many of the phenomena studied in con-
temporary cognitive psychology.
FUNDAMENTAL ISSUES, MODELS,
AND THEORIES
Historical Background
Astronomers in the first half of the nineteenth century made
the initial contribution to the measurement of RT by estimat-
ing the time it took a star to reach the midline of a grid of
vertical lines relative to when it first entered the grid (see
Woodworth, 1938). Although this was a clever method of
measuring RT, individual differences in the judgment of when
the star entered and reached the midline resulted in unreliable
readings from one astronomer to another. In an attempt to
compensate for individual differences, a personal equation
was developed in which a constant correction was made in
order to equate the readings of astronomers. However, later
investigations showed that the difference between two indi-
viduals was not constant after all.
The study of action selection was of central concern in
the last half of the nineteenth century. Interest arose out of
issues concerning the speed of nerve transmission. Most
physiologists thought that nerve transmission occurred too
rapidly to be measured. However, Helmholtz (1850) con-
ducted an experiment in which he stimulated motor nerves
of frogs and measured the time between the presentation of
the stimulus and muscular contraction. He estimated the rate
of nerve transmission to be 26 m/s. One important contri-
bution of this work was to demonstrate that the durations
of nervous systems’ processes are measurable. Helmholtz
was also the first to measure RT in a procedure intended toFigure 11.1 Sample Palm Beach County, Florida, butterfly ballot in the 2000 U.S. presidential election.