Intro to Psych - WEEK 2

Biopsychology and Neuroscience

What are some methods to study the living brain?

EEG, MRI, fMRI, fNIRS, brain stimulation

How do EEG’s work? What are some advantages?

• Places electrodes on scalp to measure electrical activity of brain cells 

  • Has millisecond precision

  • Measures how brain responds to stimuli

  • E.g study sleep stages

How do MRI’s work? What are some advantages?

• Uses magnetic fields and radio waves to create detailed pictures of brain structure

  • Revolutionised how the brain looks while thinking, feeling etc.. 

How do MRI’s work?

• Reviews which areas of the brain are active through the blood flow 

  • More oxygen needed in that area, so blood flows there

How do fNIRS’s work?

• Uses infra-red light to measure brain activity through changes in blood oxygen

How does brain stimulation work? What are some advantages? How about deep brain stimulation?

• Low level currents/magnetic pulses to the scalp

  • Can enhance or impair certain functions

  • Can then review which part of the brain is responsible for which function

  • Non-invasive, don’t last permanently

HOWEVER… deep brain stimulation is invasive and could last a long time because it requires drilling a hole into the head

What is the nervous system? (HINT: Also mention soma, myelin sheath, dendrites…)

• Made up of multiple neurons

• Neurons bundled together forms nerves

• Soma receives signals from multiple dendrites and decides whether to pass on the information to the axon

• Myelin sheath = insulation, speeds up signal

What does excitatory mean? What are some examples of excitatory chemicals?

When receptor binds, it can excite the next neuron and cause it more likely to fire. Examples include:

• Acetylcholine

• Noriephinepherine

• Dopamine

• Serotonin

• Glutamate = involved in learning, memory formation, nervous system development, synaptic plasticity

What does inhibitory mean? What are some examples of inhibitory chemicals?

Makes the neuron less likely to fire.

• GABA = Calms neural activity

How is dopamine associated with addiction to drugs?

Stimulates pathway associated with it

• Interferes with neurotransmitter systems

What are agonists and antagonists? How do they function? What are some examples of agonists and antagonists?

• Functions similar to neurotransmitters (AGONIST) or opposite of it (ANTAGONIST)

  • Morphine = Agonist, can simulate endorphins which then help prevent pain

  • Alcohol = Antagonist, block/reduce neurotransmitters from binding

What is the CNS composed of?

Brain + spinal cord

What is the spinal cord made up of?

• Sensory neurons/Afferent neurons

• Motor neurons/Efferent neurons

• Interneurons

What does the peripheral nervous system do?

Connect the CNS with the rest of the boddy

What are the two parts of the peripheral nervous system?

Automatic nervous system and somatic nervous system

What does the automatic nervous system do?

Help trigger fight or flight

• Automatically regulates glands, internal organs, blood vessels, pupil dilation, digestion, and blood pressure

What are the two parts of the automatic nervous system?

Parasympathetic division and sympathetic division

What is the function of the parasympathetic division?

• Helps save energy

• Maintains the body’s function under ordinary conditions

What is the function of the sympathetic division?

• Prepares the body to react and expend energy in in times of stress

What is the somatic nervous system?

• Carries sensory information

• Controls movement of skeletal muscles

What are the two parts of the somatic nervous system?

Sensory system (afferent)

Motor system (efferent)

What is the function of the sensory system?

Carries messages from sensory organs to CNS

What is the function of the motor system?

Carries messages from CNS to muscles and glands

What is the function of the endocrine system?

• Releases hormones into bloodstream, affecting entire body

• Glands secrete hormones

• Influences body behaviour, emotions and development

What is known as ‘the master gland’? What is its function

• Pituitary gland

• Secretes many different hormones, may even affect other glands

• CONTROLLED BY THE HYPOTHALAMUS

What are some of the other types of glands?

• Adrenal glands = Secretes adrenaline

• Thyroid glands = Affects metabolism

• Pancreas = Secretes insulin, helps to manage blood sugar

What is the hindbrain’s function?

Keeping us alive

What are some parts of the hindbrain?

Medulla, Pons, Reticular formation, Cerebellum (MY PONY READS CRIME)

What is the medulla’s function?

Breathing, heart rate, blood pressure

(MEDULLA = MY = ME = WHAT I NEED TO LIVE)

What is the pons’s function?

• Connects different brain areas

• help coordinate movement and sleep cycle

• (PONS = PONY = MOVING + SLEEPING + CONNECTING)

What is the function of the reticular function?

• Helps determine wakefulness

• Controls attention

• (RETICULAR = READS = WAKEFULNESS AND ATTENTION)

What is the function of the cerebellum?

• Control balance, muscle coordination, fine motor skills, higher order cognitive function

What is the limbic system?

Brain system involved in emotions, memory, and drive.

What are the different parts of the limbic system?

Thalamus, Hippocampus, hypothalamus, amygdala, cingulate cortex (THE HUGE HAIRY ANT CAKE)

Thalamus

Relays information from sensory organs to cerebral cortex, helping to make sense of it.

Hypothalamus

Controls when we feel hungry/full, regulates sleep cycle and body temp, and links the brain to endocrine glands.

Hippocampus

Brain structure that plays a role in learning and memory.

Amygdala

Brain structure that triggers the fight or flight response.

Cingulate cortex

Structure that plays a role in emotion and thinking, helping to detect errors.

What is the occipital lobe?

The visual processing centre of the brain.

What is the occipital lobe made up of?

Primary visual cortex and visual association cortex

What is the function of the primary visual cortex?

Receives raw visual information

What is the function of the visual association cortex?

Processes raw visual information

What is the function of the parietal lobe?

 Process touch, temperature, body position, spatial awareness from skin etc…

What is the parietal lobe made up of? What is the function of it?

Primary somatosensory cortex = Receives data about sensations in skin, muscles, joints

What is the temporal lobe made up of?

Primary auditory cortex, auditory association cortex, wernicke’s area,

What is the function of primary auditory cortex

Detects audio, such as discrete qualities of sound like pitch and volume.

Auditory association cortex

Interprets auditory information.

Wernicke's area

Interprets written and spoken language.

What is the function of the frontal lobe?

Planning, decision making, fluent speech

What is the frontal lobe made up of?

Motor cortex, prefrontal cortex, brocca’s area

Motor cortex

Sends commands to muscles.

Prefrontal cortex

Handles executive functions, like decision making and thinking of the future.

Broca's area

Vital for the formation of speech.

What is the role of the cerebral cortex?

Thinking and consciousness

Corpus callosum

Connects the two hemispheres of the brain.

contralateral pathways

Each brain hemisphere controls the opposite side of the body

• HOWEVER… both hemispheres are not identical

• FOR RIGHT HANDED PEOPLE: The left hemisphere is for language, reading, making them into meaning. Right hemisphere becomes for understanding visual-spatial relationship, emotions, pattern-recognition

• FOR LEFT HANDED PEOPLE, it is the opposite of the above.

split brain patients

Individuals with surgically severed corpus callosum

• Can only see and process things with one side of the body, can’t do with the other side

Neuroplasticity

The brain’s ability to change its structure and function based on new experiences

How does neuroplasticity happen?

Neurogenesis: Formation of new neurons

Synaptic pruning = Elimination of unused connections, making neurons available for future development