Reaction time studies that concern
accurate measurement of human mental
processes were one of the earliest
and most important experiments in
experimental psychology. It measured
how long it takes an individual to
respond to different stimuli.
Interests in the measurement of
human reaction time first began in
the field of physiology. Affected by
Dutch physiologist F.C. Donders
(1865) who was interested in
measuring time needed for human
mental processes, Wundt conducted
mental chronometry study which
concerns measuring reaction time of
various human mental processes and
calculating time of metal processes
involved through the subtraction
method.
This category of
apparatus frequently refers to
instruments for mental chronometry.
Mental chronometry is a type
of study that is aimed to measure
the processing time for various
mental processes, and is a broad
term that includes reaction time
studies and time-sense studies. In
the particular context of
psychological research, these
instruments have undergone
development in several widely
differing directions. First type of
apparatus includes chronograph,
which may be categorized as being
analogous, in its principles of
operation, to the graphic recording
devices. It permits the measurement
of extremely small time intervals
all the way down to 1/10,000 of a
second, even granted that the
limiting values of those time
intervals may vary in their general
range with the type of experiment
(sometimes they are positive,
sometimes negative). The Institute
owns an older instrument of this
kind that was constructed by the
technician K. Krille and a more
recent version constructed by the
current technician for the
Institute, E. Zimmermann. Three
Hipp chronoscopes were
also available, two older and one
more recent, as well as the
necessary accessories that go with
them. All of these time-measuring
devices were utilized in the context
of reactionĄŻ experiments, with their
various modifications, to measure
the time elapsing from the moment a
stimulus has its effect on an
observer to the moment at which a
voluntary reaction is made by the
observer to that stimulus; the
researcher also takes a particular
interest in the variety of
psychological processes that may
occupy the reaction interval. The
calibration of these chronoscopes is
facilitated by the use of the
chronograph.
Apparatus designed
for the investigation of the mental
representation of time can be added
to these chronometric
instruments. Among these are the
varieties of so-called "time-sense
apparatus," all of which are
designed to present sensory
impressions (e.g., sound, visual
stimuli) at precisely measured time
intervals, at the same time as
either keeping constant or
systematically varying the intensity
and the quality of each individual
stimulus. The Institute possesses
both a small and a large version of
such an apparatus; both can be
connected to a kymograph
(ideally, a Baltzar kymograph);
the larger version is particularly
well suited for a wide variety of
applications.
