Parts of the Brain

Brain Stem

Brain Stem

• controls basic functioning (evolutionarily the oldest part, so most living creatures have it)

• made up of

  • medulla

  • pons (+ reticular formation)

Medulla

controls heartbeat, lungs, digestion

pons

bridges brain and spinal cord

bridges 2 hemispheres of cerebellum

helps with coordination/symmetry

reticular formation

a region in the pons

controls alertness

is a neural network

responsible for sleep/wake cycles

works w/melatonin and circadian rhythm

Cerebellum

balance, coordination, movement

plays role in:

• classical conditioning memory

• procedural memory

Thalamus

structure in the midbrain

• like a router, sorts and sends data

• first place where all the senses are processed EXCEPT for smell

• then relays to rest of the brain

• links brain stem and cortex

limbic system

“the emotional center”

composed of:

• hippocampus

• amygdala

• hypothalamus

Hippocampus

in the limbic system

• processes everyday new memories

Amygdala

brain region in limbic system

threat detection

processes negative emotions (anger, fear, etc.)

Hypothalamus

in the limbic system

• homeostasis (circadian rhythm, hunger)

• 5 Fs: Freeze, flight, fight, feed, fuck

• works with the pituitary gland

basal ganglia

a subcortical structure

helps with motor control (works with acetylcholine)

if damaged, causes shaking

Nucleus Accumbens

brain region part of the reward system

lights up when pleasurable activity

Cerebral cortex

the outermost layer of brain

like 85% of brain

where you process all the senses (thalamus reroutes stimuli to here)

lots of wrinkles = more surface area

composed of 4 lobes

Frontal lobe

one of the four lobes

• contains

  • pre-frontal cortex

  • motor cortex

  • Broca’s area

motor cortex

in frontal lobe

= voluntary movement

Pre-frontal cortex

in frontal lobe

= executive functioning (prospective thinking. helps understand cause and effect, multiple directions)

• abstract reasoning

• decision-making/judgement

• personality

Broca’s area

in frontal lobe (LEFT)

= language production

• helps to make sense of language, make coherent sentences

• writing and speaking

if damaged: can only say one or two words (but others can understand what you mean)

Parietal lobe

one of the four lobes

= touch

somatosensory cortex

in parietal lobe

= processes touch (pain, pressure, and temp)

= proprioception (where you are in space)

Homunculus

= map that shows proportions of somatosensory cortex

• the more space, the more sensitive

  • ex. big face = more nerves in the face that connect to somatosensory cortex

Occipital Lobe

one of the four lobes

= vision

visual cortex

in occipital lobe

= color, object recognition

optical nerve runs all the way from eye to this cortex

Temporal Lobe

one of the four lobes

= near temples

= hearing

auditory cortex

in temporal lobe

= processes hearing

Wernicke’s Area

an association area in the left temporal lobe

= language understanding (need language production first)

if damaged: incoherent gibberish, but fluent

Fusiform facial area

in temporal lobe

= facial recognition

association area

an area thats not committed to sensory/motor function areas

= scattered all over the cerebral cortex, but near primary input locations

• links sensory input with stored memories

• INTEGRATION of new info with old info

• learning, memory, thinking, speaking

• working memory needs association area

Brain Lateralization

= “right and left hemisphere of cortex have slightly different jobs”

Broca and Wernicke

these two did autopsy to to discover language areas (1870s)

Penfield

researcher who used electrode stimulation to design the homonculus

Sperry

researcher who cut the corpus callosum of cats

won noble prize

Corpus Callosum

band of fibers that connects right and left hemispheres of the cortex

just like how pons is bridge for cerebellum, __ ___ is bridge for hemispheres

no, one hemisphere can’t be more dominant than the other for a person

however, for everyone, different functions are localized in a MAJORITY of one side

does left and right-brainedness exist?

left hemisphere

where is language mainly processed?

Left Hemisphere

hemisphere that does sequential processing (step-by-step)

• language functioning (speaking, writing, reading)

• analytical (math)

Right Hemisphere

hemisphere that does holistic processing (big-picture)

• art/music/facial recognition

• irony/sarcasm

• spatial reasoning (rotating object in head)

• processed in right brain

you know it is a triangle, but you can’t recall the word

(can draw it)

If corpus callosum is cut and you see triangle in left vision,

• processed in left brain

language = can identify and say “circle!”

If corpus callosum is cut and you see circle in right vision,