Unit 1 Part 2 APPsych Study Set

The brainstem

• oldest region of the brain, necessary for survival

Medulla (part of brainstem)

• controls functions that occur w/out conscious thought

  • heart rate

  • breathing

  • blood pressure

• UNCONSCIOUS SURVIVAL FUNCTIONS

Reticular Activating System (reticular formation)

• network of nerves - vital in survival functions:

  • attention

  • arousal

  • alertness

• being aware something has come into your environment in order to survive threats

• SURVIVAL FUNCTIONS

cerebrum

• contains the left & right cerebral hemispheres

Cerebral Cortex

• thin layer of neural cells that cover the cerebral hemispheres

• responsible for most of the sophisticated INFORMATION PROCESSING of the brain

• contains the Limbic system along w/ the cerebrum

Cerebellum

• cereBELLum- BALANCE & equilibrium

• coordinates sequences of movement

  • ex: walking

• supports NON-VERBAL learning and skill learning

  • occurs without conscious awareness

a hemispheres subdivisions of the cortex (4 lobes)

• frontal

• parietal

• occipital

• temporal

besides the 4 lobes the cerebrum & cerebral cortex also include:

the limbic system and corpus callosum

parts of limbic system

• thalamus

• hypothalamus

• hippocampus

• amygdala

thalamus

• “sensory switchboard”

• incoming sensory info (except smell) is received & sorted/processed here before being sent to the cortex for further interpretation

hypothalamus

• FIGHT or FLIGHT response

• HUNGER motivation

• directs activities that help as maintain homeostasis

• controls endocrine system

amygdala

• linked to emotions

  • 3 A’s

    • Anger Aggression, Afraid (aka fear)

• helps ingrain highly emotional memories

hippocampus

• converts short term memory into long term memory

• creates, processes, and retrieves memories of facts and events but DOES NOT store them

• dysfunction associated w/ Alzheimer’s 

• losing hippocampus due to surgery or injury will lose their ability to form NEW memories

frontal lobes

• prefrontal cortex

• motor cortex

• association areas

• Broca’s area (left side only)

prefrontal cortex (in frontal lobes)

• involved in cognitive functions

  • thinking, planning, decision making, impulse control

motor cortex (in frontal lobes)

• involved in initiating voluntary movement

• contralateral hemispheric organization

  • LH- controls movement on the right side of body

  • RH- controls movement on the left side of body

• areas of the body that make precise movements get more tissue from this cortex in the brain devoted to them 

  • ex: fingers or lips

Broca’s Area (left frontal lobe only)

• involved in expressing and producing speech

• damage can lead to Broca’s aphasia which is the inability to produce speech

parietal lobes

• somatosensory cortex

somatosensory cortex (in parietal lobes)

• represents sense of touch

• more sensitive parts of the body have more tissue devoted to them on this strip

  • ex: fingers and lips

Occipital Lobes

• primary visual cortex

primary visual cortex (in occipital lobes)

• visual processing

• damage to the Occipital lobe can cause blindness despite the fact that there may be no damage to the eyes

  • due to the interpretation process being lost

temporal lobes

• primary auditory cortex, aka hearing

• LEFT temporal lobe contains Wernicke’s area

Wernicke’s Area (in left temporal lobe)

• involved with understanding and comprehending language 

• Damage can lead to Wernicke’s aphasia which is the inability to comprehend or understand speech

parietal lobes contains

• somatosensory cortex

• association areas

occipital lobes contains

• primary visual cortex

• association areas

temporal lobes contain

• auditory cortex

• association areas

•  wernicke’s area (left side only)

case studies for studying the brain

• for a long time, scientists would observe cases of accidental brain damage in order to understand the brain better

Lesions

• scientists can learn about the brain by observing the effect on brain function when brain tissue is destroyed

• this tissue destruction is a lesion

• these may occur due to disease, trauma, during surgery, or experimentally

Electroencephalogram/EEG (type of brain scan)

• measures brain’s electrical activity 

• the electrodes that is put on the scalp look for normal/abnormal brain wave patterns to diagnose or treat certain conditions

• help diagnose sleep disorders

functional MRI/fMRI (type of brain scan)

• can detect BOTH structure and function

  • measures oxygen and blood flow to brain regions

• used ONLY to look at the brain

• can be used to understand the parts of a patients brain that become active & inactive during various tasks

pathways that use the contra lateral hemispheric organization

motor and sensory pathways

corpus callosum

bundle of fibers that connect the two hemispheres

hemispheric specialization aka lateralization

• tendency for 1 hemisphere to excel at a certain skill compared to the other side

• understood using split brain research

left hemispheric specialization

• language

• analysis

• calculations

right hemispheric specialization

• spatial abilities

• facial recognition

right visual field

• right side of each eyes VF

• its info goes to the LH

left visual field

• left side of each eye’s VF

• its info goes to RH

Visual field diagram

RVF LVF

LHemi RHemi

RHand LHand

neuroplasticity

• the brains ability to change by building new pathways based on experience or reorganizing after damage

• especially in childhood

• some damage is permanent though

  • neurons of a severed brain and spinal cord cannot regenerate

• sometimes it can reorganize and functions that were once under the control of a removed or damaged part of the brain can be taken up by a working part of the brain

neurogenisis

• process by which a brain area that has been deprived of its typical sensory input begins to process new inputs from different sensory modalities

dual processing

• processing more information than we are consciously aware of

• things are processed on either a “high road” or “low road” in our brain

circadian rhythm

• internal biological clock, regular body rhythms like temp and sleep/wake cycle that occur on a 24h cycle

Sleep stages

• NREM sleep

  • stage 1

  • stage 2

  • stage 3

• REM sleep

• the cycle repeats about every 90-120 min

NREM

• distinct EEG patterns

• amount decreases as night goes on

stage 1 aka NREM 1

• beginning of cycle for a few minutes

• lightest stage

• hypnagogic sensations

hypnagogic sensations

• images resembling hallucination, or sensations of falling, floating weightlessly

stage 2 aka NREM 2

• typically lasts about 20 min

• clearly asleep then

stage 3 aka NREM 3

• aka body sleep or slow-wave sleep

• typically lasts for about 30 min

• deep sleep hard to awaken

• hormones are released into bloodstream 

• essential for good health, w/out you are at a greater risk of illness

REM sleep

• heart rate rises

• breathing becomes rapid or irregular

• eyes dart in momentary bursts- indicating dreams

• arousal of genitals

• muscles relax, essentially paralysis

• sometimes called paradoxical sleep

  • cant move, but has high brain activity

• increases over the course of the night

what affects our sleep patterns?

• age

• genetics

• cultural, social, economic influences

• light exposure

restoration theory

• sleep restores our physiological functions during NREM

• sleep restores our mental processes during REM

• needed because our bodies wear out during the day

memory consolidation theory

• NREM 3 consolidates memories by strengthening neural connections of things we’ve learned

• sleep reactivates experiences stored in the hippocampus & moves them to permanent storage elsewhere in the cortex

sleep deprivation affects our…

• brain

• heart

• immune system

• joints

• muscles

• gain of weight

insomnia

• ongoing difficulty falling/staying asleep

• affects 1 in 5 adults

• chronic tiredness, increase risk of depression, hypertension, and more

narcolepsy

• sudden attacks of overwhelming sleepiness

• affects 1-2000 adults

• risk of falling asleep at dangerous moments

sleep apnea

• stopping breathing repeatedly while sleeping causing one to constantly wake up

• affects 1-20 adults

• fatigue, depression, and association w/ obesity

sleepwalking

• repeated episodes of complex motor behavior such as walking while asleep

• occurs in stage 3

• 1-15 in 100 people in the general pop.

• no serious concerns

• won’t remember the next morning

REM sleep behavior disorder

• acting our dreams while asleep

• vocalizing dreams

• risk of accidental injury to self or sleep partner