20

CHAPTER II

REACTIONS 21

The Reaction Time Experiment 22

Reflex Action 24

The Nerves in Reflex Action 26

Internal Construction of the
Nerves and Nerve Centers 31

The Synapse 34

Cooerdination 37

Reactions in General 39

Exercises 42

References 44

CHAPTER III

REACTIONS OF DIFFERENT LEVELS 45

Different Sorts of Stimuli 47

The Motor Centers, Lower and Higher 49

How the Brain Produces
Muscular Movements 53

Facilitation and Inhibition 54

Super-motor Centers in the Cortex 56

Speech Centers 57

The Auditory Centers 59

The Visual Centers 62

Cortical Centers for the Other Senses 68

Lower Sensory Centers 64

The Cerebellum 66

Different Levels of Reaction 65

Exercises 67

References 67

CHAPTER IV

TENDENCIES TO REACTION 68

Purposive Behavior 70

Organic States that Influence Behavior 72

Preparation for Action 74

Preparatory Reactions 77

What the Preparatory
Reactions Accomplish 79

What a Tendency Is,
in Terms of Nerve Action 82

Motives 84

Exercises 86

References 88

CHAPTER V

NATIVE AND ACQUIRED TRAITS 89

The Source of Native Traits 90

Reactions Appearing at
Birth Must Be Native 91

Reactions That Cannot Be
Learned Must Be Native 92

Experimental Detection
of Native Reactions 93

Is Walking Native or Acquired? 95

Universality as a Criterion
of Native Reactions 97

Some Native Traits Are
Far from Being Universal 98

Why Acquired Traits Differ from
One Individual to Another 99

What Mental Traits Are Native? 100

Exercises 103

References 1