Developmental psychology.pdf

140 Modes of Awareness
'I've often wondered if our
"tastes" don't change a good deal
as we grow older. I really have
noticed a change in myself when it
comes to a taste for dizziness. As a
kid I loved to twirl around and
around or roll over and over down
a hill until my head was "spinning"
so much I couldn't stand up. Now I
have no desire at all for that kind of
feeling. Is it possible that
something in my ears has changed
so that I am more sensitive—or
less sensitive—to that kind of
motion?
canals is at right angles to the others, one corresponding to each of the three planes of
space. Turning the head in any direction produces movements of hair cells in at least
one canal (Figure 5.14).
Research and Demonstrations Human beings are generally exposed only to mild
rotary motion, as when a car rounds a curve or some brief spinning motion is involved
in a dance or athletics. When the movement is pronounced and sustained, motion
sickness can result, caused partly by activity in the nonauditory labyrinth. Sometimes
further experience enables the individual to become accustomed to this nauseous feeling,
and adaptation can be accelerated by simulated exposure, as in motion pictures (Parker
& Howard, 1974).*
Despite the absence of prolonged rotary and linear motion in most of our lives,
the future probably will bring closer study of the mechanisms that mediate these experiences.
The semicircular canals and vestibular system will be most important for
life in space, with its immense changes in acceleration and gravitational pull.
SENSATION AND PERCEPTION
With the frog on the kitchen floor, or wherever it would land, one might suppose the
story is finished. But something remains, for our survey of the senses has omitted an
important point.
What we know about the world is due to more than the stimulation of our
various sense organs. This information is combined with that already stored in the
brain, which is what we call memory. In other words, we add past experience to current
sensations; we make some interpretation or derive meaning in a process called perception.
We experience more than warmth, wetness, and a mild popping sound. We combine
this information with past experience and we know that a pot is boiling on the
stove. Perception is an organized, unified experience, usually arising from several sensory
processes.
Intersensory Perception
Recognizing that our senses usually operate in conjunction with one another, we often
speak of multisensory or intersensory perception. By this term, we mean that information
is obtained from two or more senses simultaneously, and it is added to acquired
information (Figure 5.15).
Senses as Interrelated On this basis the frog in the pot would have been confronted
with far more than an overheated skin. The rising bubbles would have disrupted its
balance and perhaps generated a sense of passive motion; the popping and hissing would
have constituted auditory stimulation; steam might have disrupted the animal's vision;
and the amphibian might even have smelled something peculiar, depending upon what
was burning. Through some combination of t these sensations, there is no doubt that
any normal frog would have perceived dangef,""or at least it would have been aroused
by the circumstances.
At the human level, eating a meal is an intersensory experience. What is commonly
called taste is a composite of gustatory, olfactory, and cutaneous sensitivities.
Uncooked potato and apple are discriminated only when vision or smell is added to
taste. Uncooked cauliflower can be identified by noting the texture, which is a cutaneous
experience. Even our perception of saltiness and sweetness is influenced by texture
(Christensen, 1980).
We orient ourselves in space not only by balance and kinesthetic receptors but
also by visual and auditory cues. A person tipped backward in a dentist's chair is aware
of the situation through what is seen, what may be heard, and also through information