1.4 Parts of the Brain

Left Hemisphere

Left half of the cerebrum which takes care of sensing, perceiving, motor control, and higher level cognitive processes

• speech, language, recognition of words, letters, and numbers

Right Hemisphere

Right half of the cerebrum

Concerned with perception, motor control, and higher level & cognitive processes, creativity, context, recognition of faces, and objects, and places

Corpus Callosum (Fissures)

Large tract of fibers which run across the longitudinal fissure of the brain which is the principal connection between both halves of the brain

• connect the two hemispheres of the brain

Split Brain Research

The corpus callosum is severed to some degree in order to reduce or prevent seizures

• corpus callostomy

• the two parts of the brain can no longer speak to each other

EEG (electroencephalography)

Method of studying brain waves using electroencephalograph which amplifies brain electrical activity

• amplified recording of the waves of the electrical activity of the brain’s surface

• Measured by electrodes placed on the scalp

• Filter out brain activity from any unrelated stimulus, searching for a specific instance

  • What is happening when this happens?

fMRI (function magnetic resonance imaging)

Used to localize areas of cognitive activation based on correlation between brain activity and blood property changes

• technique for revealing blood flow and therefore brain activity by comparing successive MRI scans

  • MRIs look at radio waves of soft tissue

• fMRI you actively do something, whereas regular MRI you are still

Neuroplasticity

Ability of the nervous system to change in response to stimuli

• brain’s ability to change, especially during childhood by reorganizing after damage or by building new pathways based on experience

Cerebral Cortex

Layer of gray matter which covers the outside of the cerebral hemispheres in the brain

Associated with higher cognitive functions such as learning, language, perception, and planning

Cerebellum

Portion of the hindbrain which rests on the brain stem which modulates muscle movements and contractions

• “little brain” near the rear of the brainstem

• Functions: processing sensory input, coordinating movement, balance, enables non-verbal learning and memory

• Alcohol influences the cerebellum which is why drunk people can’t walk

• If injured: jerky movements, trouble texting, trouble walking

• Reasons you can answer questions quickly: cerebellum

Hippocampus

Seahorse shaped part of forebain, declarative memory and learning

Occipital Lobe

Part of brain on the way back, responsible for sight

Temporal Lobe

Part of brain relating to the temples/around them, responsible for hearing, balance,and feeling

Broca’s Area

Part of the brain responsible for speech

Limbic System

Loosely defined group of brain nuclei that innervate to connect visceral and autonomic functions, below cerebral hemispheres

• includes: amygdala, hypothalamus, hippocampus, thalamus, and pituitary gland

• Associated with emotion and drive

• lima bean portion of the brain

Medulla

Medulla oblongata, most inferior part of the hindbrain, conducts impulses beteween the spine and the brain

• base of the brain stem, slight swelling of the spinal cord right as it enters the skull

  • Autonomic functions like breathing and heartbeat

  • Any destruction → life immediately threatened

Reticular Activating System

Involved with arousal, alertness, and sleep-wake schedules

Part of reticular formation

• severe activating system damage → go into a coma and never wake back up

• If stimulated, wake up

• Puts the reticular formation into gear, wakes it up and activates it

Amygdala

Almond shaped in temporal lobe, basal gangli

Threat, fearr, memory, learning, anger

• Without amygdala, no fear, no anger, very mellow

• One part of it controls fear and the other controls anger

• Lesions on amygdala can cause anger and amygdala dysfunction

• Fear and rage

Parietal Lobe

Left and right sides of the brain which are responsible for hand movement and coordination

Frontal Lobe/Prefrontal Cortex

Front part of the brain often association with maturity and making decisions

Wernick’s Area

Area of the brain association with interpretation of sounds

Thalamus

Part of the brain, gray matter, forms diencephalon, walls form third ventricle

• receives information from all the senses except for smell, sends replies to areas of brain responsible for all senses except this

• Sits atop the brainstem which is a pair of egg shaped structures that act as the brain’s sensory control center

• Also receives replies from brain regions and directs them to the medulla

Hypothalamus

Below the thalamus, wizard’s hat

Controls autonomic system, sleep, thirst, and sexuality, eating, body temperature, governs endocrine system, linked to emotion and reward

Brainstem

Part of the brain which sends out and receives signals to and from the rest of the body

• central core of the brain

• Begins where the spinal cord swells as it enters the skull

• Responsible for autonomic survival functions

• Contralateral hemispheric organization

Sensorimotor Cortex

Responsible for sensing and acting upon external stimuli

Motor Cortex

Responsible for movements of the body and bodily functions

Aphasia

Language impairment from damage to the left hemisphere

Pons

• sit above the medulla and help coordinate movements and control sleep

Reticular formation

Nerve network that filters information and plays an important role in controlling arousal or state of alertness

• extends into spinal cord right up through the thalamus

• Filters information and all stimuli, gets rid of unnecessary information

• When RAS kicks in, jumps starts this reticular formation

• Other stimuli and transmitters come through, if they dont have to do with alertness or arousal, thrown out