Chapter Four: Neurons, Hormones, and the Brain

Two Stubborn Issues in Brain Research

INTRODUCTION

Two mysteries of the brain.

WHAT'S AHEAD

• How do biological theories of dreaming differ from the familiar Freudian view?
• Do men talk about sports and women about feelings because their brains are different?

KEY CONCEPTS

Why Do We Dream?
Are There "His " and "Her" Brains?

---

Why Do We Dream? [p.138]


INTRODUCTION

Why do we sleep and dream.

KEY CONCEPTS EXPLAINED

Sleep

• To physically recuperate from the demands of the day.
• Helps the brain function efficiently.
• Sleep deprivation has negative consequences.

Dreaming - the purpose of dreaming is not so clear.

Realms of Sleep

Dreaming is associated with periods of rapid eye movement. (REM)

• Eyes move.
• Heart rate, blood pressure, and breathing increase.
• EEG shows rapid and irregular patterns.
• Skeletal muscles go limp.
• Paradoxical sleep.
• Cycle occurs every 90 minutes.

Stages of Sleep

1. Drifting on the edge of consciousness.
2. Sleeping soundly.
3. Hard to arouse.
4. Deep sleep and difficult to awaken.
5. REM

Dreaming Brain

• Freud believed there were hidden meanings to gratify unconscious wishes and longings.
  
  
• Conscious preoccupation with daily life.
  
  
  • Deal with every day problems.
    
    
  • "Successful" dreams resolve issues of loss and recover more quickly from a divorce.
    
    
• Biological Theories
  
  
  • Period of consolidation to strengthen synaptic connections and weaken others (dumping the garbage each night).
    
    
  • Activation-Synthesis Theory - Brain stem mechanisms fire spontaneously during REM and the cortex tries to make sense of the signals by synthesizing them with existing memories and produce a coherent interpretation.

GLOSSARY

		rapid eye movement (REM) Sleep
		activation-synthesis theory

LINKS About Dreams

• weblink: The Quantitative Study of Dreams at UC, Santa Cruz.
• weblink: Association for the Study of Dreams.
• weblink: Everything you wanted to know about sleep.

Are There "His" and "Her" Brains? [p.141]

INTRODUCTION

Are men from Mars and women from Venus?

KEY CONCEPTS EXPLAINEDs

..Physical Differences

• No real differences in the size and shape of the splenium -- now that's a relief.
  
  
• Some evidence that there is more lateralization for some language functions in men (bad news when men have strokes).

..Effect of Brain Differences on Behavior

• Popular Beliefs: Women are more intuitive and verbal, while men are better at math but won't ask directions when they are lost.
  
  
  
• Problems with Popular Beliefs
  
  
  1. These gender differences are gender stereotypes. There is more overlap between the sexes than differences between them.
     
     
  2. Biological differences do not necessarily have behavioral implications.
     
     
  3. Brain differences might be the result not the cause of behavioral differences.

  4. A student submitted this definitive description of the differences between the brains of men and women:
     • The Male Brain
     • The Female Brain

LINKS

Your author wants to call a halt to the "Gender Wars."

Next Topic - Taking Psychology With You..................................Chapter Contents