Bibliography 107together into a seamless whole would also be considered to be
an illusion. Since we now understand the physiology underly-
ing both the visual and the auditory processes, we fail to see
either noncorrespondence or illusion in either of these
phenomena.
Apparent motion (Wertheimer’s phi phenomena), percep-
tual organization, stereoscopic depth perception, singleness
of vision, size constancy, shape constancy, brightness con-
stancy, color constancy, shape from shading, adaptation to
heat, cold, light, dark, touch and smell, the nonlinearity of
judged stimulus magnitudes, intensity contrasts, brightness
assimilation, color assimilation, pop-out effects, filling-in of
the blind spot, stabilized image fading, the Purkinje color
shift, and many more such phenomena all started out as “illu-
sions” and instances of noncorrespondence between percep-
tion and reality. As we learn more about these phenomena we
hear less about “illusion” or “distortion” and more about
“mechanism” and “normal sensory processing.”
The psychological study of sensation and perception re-
mains extremely eclectic. Perceptual researchers still are
quick to borrow methods and viewpoints from other disci-
plines. Physical, physiological, optical, chemical, and bio-
chemical techniques and theories have all been absorbed into
the study of sensory phenomena. It might be argued that a
physiologist could study sensory phenomena as well as a psy-
chologist, and, as the history of the discipline shows, if we are
talking about matters of sensory transduction and reception,
or single cell responses, this is sometimes true. David Hubel
and Torston Wiesel were physiologists whose study of the
cortical encoding and analysis of visual properties did as
much to advance sensory psychology as it did to advance
physiology. Georg von Bekesy (1899–1972), who also won
the Nobel Prize for physiology, did so for his studies of the
analysis of frequency by the ear, a contribution that is appre-
ciated equally by physiology and psychology. Although some
references refer to Bekesy as a physiologist, he spent two-
thirds of his academic career in a psychology department and
was initially trained as an engineer. Thus, sensory and per-
ceptual research still represents an amalgam of many research
areas, with numerous crossover theories and techniques.
It is now clear that on the third major theme, the distinction
between sensation and perception, with a possible strong sep-
aration between the two in terms of theories and methodolog-
ical approach, there is at least a consensus. Unfortunately the
acceptance of this separation has virtually led to a schism that
may well split this research area. Psychology has accepted the
distinction between sensation (which is primary, physiologi-
cal, and structural) and perception (which is based on
phenomenological and behavioral data). These two areas
have virtually become subdisciplines. Sensory research re-
mains closely tied to the issue of capturing a stimulus and
transferring its information to the central nervous system for
processing, and thus remains closely allied with the physical
and biological sciences. Perceptual research is often focused
on correspondence and noncorrespondence issues, where
there are unexpected discrepancies between external and in-
ternal realities that require attention and verification, or where
we are looking at instances where the conscious percept is ei-
ther too limited or too good in the context of the available sen-
sory inputs. It is more closely allied to cognitive, learning, and
information-processing issues. Thus, while sensory research
becomes the search for the specific physical or physiological
process that can “explain” the perceptual data, perceptual
research then becomes the means of explaining how we go be-
yond the sensory data to construct our view of reality. The im-
portance of nonsensory contributions to the final conscious
representation still remains an issue in perceptual research but
is invisible in sensory research. The history of sensation and
perception thus has seen a gradual separation between these
two areas. Today, sensory researchers tend to view themselves
more as neuroscientists, while perceptual researchers tend to
view themselves more as cognitive scientists.
While the distinction between sensation and perception is
necessary and useful, the task of the future may be to find
some way of reuniting these two aspects of research. Cer-
tainly they are united in the organism and are interdependent
aspects of behavior. I am reminded of a line by Judith Guest
in her book Ordinary People,where she asked the question
that we must ask about sensation and perception: “Two sepa-
rate, distinct personalities, not separate at all, but inextricably
bound, soul and body and mind, to each other, how did we get
so far apart so fast?”BIBLIOGRAPHY(Some works used for background but not specifically cited in the
text)
Boring, E. G. Sensation and Perception in the History of Experi-
mental Psychology.New York: Appleton-Century-Crofts, 1942.
Coren, S., and J. S. Girgus. Seeing is Deceiving: The Psychology of
Visual Illusions.Hillsdale, NJ: Erlbaum, 1978.
Hearnshaw, L. S. The Shaping of Modern Psychology.New York:
Routledge, 1987.
Pastore, N. Selective History of Theories of Visual Perception:
1650–1950.New York: Oxford University Press, 1971.
Polyak, S. The Vertebrate Visual System.Chicago: Univesity of
Chicago Press, 1957.
Sahakian, W. S. History and Systems of Psychology.New York:
Wiley, 1975.
Spearman, C. Psychology down the Ages.London: Macmillan,
1937.