yourself
by aid of a hand mirror. On another person you can also observe the
"crossed" pupillary reflex, by throwing the light into one eye only
while you watch the other eye. What sort of connection do you
suppose to exist between the two eyes, making this crossed reflex
possible?

9. The lid reflex, or wink reflex, (a) Bring your hand suddenly
close to another person's eye, and notice the response of the
eyelid, (b) See whether you can get a crossed reflex here, (c) See
whether your subject can voluntarily prevent (inhibit) the lid
reflex, (d) See whether the reflex occurs when he gives the
stimulus himself, by moving his own hand suddenly up to his eye.
(e) What other stimulus, besides the visual one that you have been
using, will arouse the same response?

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REFERENCES

C. Judson Herrick, in his _Introduction to Neurology_, 2nd edition,
1918, gives a fuller and yet not too detailed account of the neurone
in Chapter III, and of reflex action in Chapter IV.

Percy G. Stiles, in his _Nervous System and Its Conservation_, 1915,
discusses these matters in Chapters II, III and IV.

Ladd and Woodworth's _Elements of Physiological Psychology_, 1911, has
chapters on these topics.

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CHAPTER III

REACTIONS OF DIFFERENT LEVELS

HOW SENSATIONS, PERCEPTIONS AND THOUGHTS MAY BE CONSIDERED AS FORMS OF
INNER RESPONSE, AND HOW THESE HIGHER REACTIONS ARE RELATED IN THE
NERVOUS SYSTEM TO THE SIMPLER RESPONSES OF THE REFLEX LEVEL.

Having defined a reaction as an act of the individual aroused by a
stimulus, there is no reason why we should not include a great variety
of mental processes under the general head of reactions. Any mental
process is an activity of the organism, and it is aroused by some
stimulus, external or internal; therefore, it is a reaction.

I hear a noise--now, while the noise, as a physical stimulus, comes to
me, my hearing it is my own act, my sensory reaction to the stimulus.
I recognize the noise as the whistle of a steamboat--this recognition
is clearly my own doing, dependent on my own past experience, and may
be called a perception or perceptive response. The boat's whistle
reminds me of a vacation spent on an island--clearly a memory
response. The memory arouses an agreeable feeling--an affective
response, this may be called. In its turn, this may lead me to imagine
how pleasant it would be to spend another vacation on that island, and
to cast ab