Psychology Unit IV: The Brain

THE BRAIN

Brain Structures

1. Hindbrain (biggest part)
2. Midbrain
3. Forebrain

Hindbrain

• structures on top of our spinal cord
• controls basic biological structures

Medulla Oblongata

• located above spinal cord
• controls: heart rate, blood pressure, and breathing

Pons

• just above the medulla
• connects hindbrain with midbrain and forebrain
• involved in facial expressions

Cerebellum

• bottom rear of brain
• means "little brain"
• coordinates fine muscle movements

Midbrain

• coordinates simple movement with sensory information
• most important structure in midbrain is the Reticular Formation (controls arousal and ability to focus our attention)
• if destroyed: would sleep

Forebrain

• what makes us human
• largest part
• consists of thalamus, Limbic system, and cerebral cortex

Thalamus

• switchboard of the brain
• receives sensory signals from the spinal cord and sends them to other parts of the forebrain
• every sense except smell

Limbic System

• hypothalamus
• pituitary gland
• amygdala
• hippocampus

Hypothalamus

• most important part of the brain
• controls body temperature, hunger, thirst, sexual arousal, and endocrine system

Hippocampus

• involved in process and storage of memories

Amygdala

• involved in how we process memory
• more involved in volatile emotions like anger

Cerebral Cortex

• made up of densely packed neurons we call "gray matter" 
• Glial cells:support brain cells
• four lobes

More Parts of the Brain

Hemispheres

• divided into two 
• contralateral control: right controls left and vice versa
• left: logic and sequential tasks
• right: spatial and creative tasks

Frontal Lobe

• abstract thought and emotional control
• contains Motor Cortex: sends signals to our body controlling muscle movements
• contains Broca's Area: responsible for controlling muscles that produce speech 
• damage to Broca's Area is called Broca's Aphasia: unable to make movements to talk

Parietal Lobe

• contains Sensory Cortex: receives incoming touch sensations from the rest of the body
• mostly made up of association areas (any area associated with receiving sensory information or coordinating muscle movements

Occipital Lobe

• deals with vision
• contains Visual Cortex: interprets messages from our eyes into images we can understand

Temporal Lobe

• process sounds sensed by our ears
• interpreted in auditory cortex
• not lateralized
• contains Wernike's Area: interprets written and spoken speech
• Wernike's Aphasia: unable to understand language, syntax and grammar jumbled

Corpus Callosum

• bridge of nerve fibers that connects or divides the two hemispheres

Brain Plasticity

• when the brain is damaged, it will attempt to find new ways to reroute messages

Cerebrum

• largest part of the brain
• divided into left and right hemispheres and divided into lobes
• contains the cerebral cortex (gray matter)
• controls voluntary movement, coordinates mental activity, and is the center for all conscious living