Brain and neuropsych

• Brain Stem


  Base of the brain + connects to the spinal cord

  Carries sensory and motor nerves to the brain

  Controls autonomic functions

  Highly developed at birth
• The Nervous System


  Composed of the CNS + PNS

  Collects and responds to information from the environment

  Controls organs and cells in the body
• Central Nervous System


  Consists of the brain+ spinal cord

  Co-ordinates the entire nervous system

  Brain is divided into two halves

  Right hemisphere controls left side of the body (vv)

  Brain controls conscious awareness and makes decisions
• Spinal Cord


  Helps the brain to monitor and regulate body processes and perform simple tasks
• Peripheral Nervous System


  A system of nerve fibres that connects and relays info between the CNS and the rest of the body.

  Sends messages via millions of nerve cells (neurons)

  Divided into sub-divisions (autonomic and somatic)
• Somatic Nervous System


  A system of sensory and motor neurons that relay sensory information to and from the CNS

  Controls vouluntary muscle movement commanded by the motor cortex

  Takes in info from our sensory organs and controls skeletal muscles.

  Has both sensory receptors + motor pathways unlike the ANS which has only motor pathways
• Fight or Flight response


  Hypothalamus identifies the threatening event

  Triggers the sympathetic division of the ANS.

  Adrenaline is released from the adrenal glands/medulla

  Adrenaline affects the cardiovascular system

  Physiological changes occur. Causing flight or fight.
• Sensory Neurons


  Carries nerve impulses from the sensory receptors in peripheral nervous system to the CNS.At the brain, brain translates impulses (sensations)Some stop at the spinal cord to process reflex actionsLong dendrites,Short axons (LS)
• Relay Neurons


  Found between sensory and motor neuronsAllows them to communicateOnly in the brain and the spinal cordShort dendrites andShort axons (SS)
• Motor Neurons


  Carries messages from the CNS to effectors in the body eg muscles and glandsShort dendrites andLong axonsThey from synapses with muscles and control their contractionsWhen stimulated, releases a neurotransmitter that binds to receptors on muscle to create movement.
• Synaptic Transmission


  Messages are passed from one neuron to another by sending neurotransmitters across the synaptic gap so that they can be picked up by the receptors on the next neuron

  Within a neuron- the signal is electric

  Between a neuron- The signal is chemical

  Synaptic transmission begins when an action potential arrives at the terminal button at the end of an axon.
• Neurotransmitters


  A brain chemical that is released across the synpatic cleft by one neurone and picked up by the next neuron. Can cause excitation or inhibition
• Summation


  When both cells receive inhibition and excitation at the same time
• Excitation


  A neurotransmitter binding with a receptor on the next neuron and increasing the likelihood that the next neuron will fire an electrical impulse as increases + charge
• Inhibition


  A neurotransmitter binding with a receptor on the next neuron and decreasing the likelihood that the next neuron will fire an electrical impulse. As increases - charge
• Neuropsychology


  The study of functions and behaviors associated with specific regions of the brain.
• cognitive neuroscience


  A field that attempts to understand the links between cognitive processes and brain activity.
• Neurological damage


  damage to the body's central and peripheral nervous system and affects the ability of neurons to function properly
• autonomic nervous system


  A subdivision of the peripheral nervous system which are responsible for involuntary functions.

  They connect the senses and the internal organs with the CNS.

  Controls heart rate digestion etc

  Divided into 2 sections- parasympathetic and sympathetic

  Controls homeostasis in body by controlling glands, muscles, internal organs
• Parasympathetic branch


  Stops the sympathetic dvision

  Rest +digest+reponse

  Returns body to normal resting state after threat has gone

  1. Decreases heart rate

  2. Constricts pupils

  3. Stimulates saliva production
• Sympathetic branch


  Responds to physiological arousal

  Fight or flight response

  Automatic response when threat is perceived

  1. Increases heart/breathing rate

  2. Dilates pupils

  3. Inhibits digestion/saliva production
• Outline James-Lange Theory of emotion

  Event, Arousal, Interpretation, Emotion

  Phsyiological Arousal- Event (Stressor or threat)

  Event triggers hypothalamus

  Sympathetic division of ANS is activated

  Adrenaline is released during physiological arousal

  Begins fight or flight response

  Brain has to interpret physiological changes so physiological changes = emotion

  No physiological changes= no emotion

  Physical change causes emotion and causes us to react in situations
• Evaluation of James- Lange Theory of Emotion

  + Real life Application

  Fear of public situations (phobia) can develop from anxiety (emotion) from falling down in public

  Emotional responses are a result of physiological arousal

  - Challenged by the Cannon-Bard Theory

  Experience emotions at the same time as physiological arousal not one after the other

  Explain emotional situations like embarrassment and draws attention to emotion
• Outline Hebb's Theory of Learning + Neuronal Growth

  Before Hebb before people thought you reached a certain age and your brain stopped developing.

  He believed that as you learn, you create more connections between neurons in the brain and synaptic connections become stronger.

  Plasticity- Not fixed in structure (brain is constantly developing)

  Learning is a like a sparkler- the trace can be permenant with practice and the trace it leaves is an engram.

  When we learn cell assemblies fire together and the more it happens = stronger synpatic connection

  Cell assembly becomes more efficient.
• Evaluate Hebb's Theory of Learning + Neuronal Growth


  + Scientific basis

  Explains cognitive behaviour and provides a scientific basis for understanding behaviour

  Possible to study learning through processes in the brain

  - Learning is reduced to a neuronal level

  Learning can be explained as a cognitive acitivity but also a social activity as we learn by observing others.

  Hebb's account 'reduces learning
• Engram


  a hypothetical permanent change in the brain accounting for the existence of memory.
• Neuronal Growth


  When a neuron frequently excites another neuron, it results in change or development in one or both of the neurons and learning becomes more effective.
• Reductionism


  Belief that human behaviour can be explained by breaking in smaller component parts.
• Penfield's aim + method

  To investigate how patients responded when parts of their brain were electrically stimulated

  
  

  Patients with epilepsy lay on an operating table and were conscious

  Only a local anaesthetic was used and he stimulated different areas of the brain using the Montreal Procedure (brain mapping)

  Recorded patients' responses
• Penfield's results + conclusion

  Gathered qualitative data

  If stimulation was applied to:

  - Somatosensory: false sense of movement

  - Occipital lobe: Colours and shadows

  - Temporal lobe: Re-living of the past/ deja-vu like experience

  
  

  The area of the temporal lobe he had stimulated had a role in storing memories of previous events

  Interpretative cortex- Stores memories of our knowledge of feelings
• Penfield's Evaluation


  + Precise method for studying the brain

  Developed the Montreal Procedure for treating epilepsy- conduct very detailed investigations of the brain by stimulating particular areas

  Data is reliable and has benefitted neuroscience for decades

  - Used an unusual sample

  Experience of epilepsy could have changed the structure and function of the brain

  May not be possible to generalise Penfield's findings to non-epileptic brains
• Tulving's aim + method


  To investigate if episodic memories produced blood flow in different parts of the brain than thinking about semantic memories

  
  

  Volunteers injected with man-made radioactive gold

  Had a PET scan whilst thought about a personal experience (episodic) or a historical fact (semantic)

  Activity was monitored on a PET scan

  8 trials in total- 4 semantic 4 episodic
• Tulving's Results + Conclusion

  Found clear differences in blood flow patterns for three of the six PPs

  Semantic memory meant greater conc of blood flow towards the back of the brain (posterior cortex)

  Episodic memory meant greater conc of blood flow towards the front of the brain (frontal lobe)

  
  

  Episodic and semantic memories are separate forms of long-term memory and they are localised in different areas of the brain
• Tulving's Evaluation


  - Sample Tulving used was small and restricted

  Blood flow was only seen in 3 PPs which means that data was inconclusive

  Difficult to generalise Tulving's results to wider population

  + PET scans produce objective and scientific data

  If PPs were following instructions they would have not been able to influence the PET scan

  Unlike other investigations as there was no demand characterisitics

  Data produced in Tulving's study is unbiased.
• What happens when you are in a sympathetic state?

  Increases heart rate

  Increases breathing rate

  Dilates pupils

  Inhibits digestion

  Inhibits saliva production

  Contracts rectum
• What happens when you are in a parasympathetic state?

  Decreases heart rate

  Decreases breathing rate

  Contracts pupils

  Stimulates digestion

  Stimulates saliva production

  Relaxes rectum
• What is a cell body?

  nucleus with genetic material (DNA)
• What is an axon?


  Carries signals from the cell body down the neuron covered in myelin sheath
• What is myelin sheath?

  Fatty layer acts as insulation
• What is the terminal button?

  small bulges at the end of axons that send messages to other neurons