Lesson 3 - Psych Biological Foundations of Behaviour PDF

Biological Foundations of Behaviour Chapter 3  The human brain Neurons An amazingly intricate Cells that receive and network of neurons transmit _____________ electrochemical signals 3 ...

Biological Foundations of Behaviour Chapter 3  The human brain Neurons An amazingly intricate Cells that receive and network of neurons transmit _____________ electrochemical signals 3  Neural Basis of Behaviour Neurons - conducting cells of nervous system Dendrites _______________ – Receive messages from other neurons Cell body – Contains genetic info; determines cell function Axon ______________ – Conducts electrical impulses Axon Terminal – Releases chemical messengers to act on next neuron End of Neuron 4  j connects different neurons 5 6  Nerve Conduction: Electrochemical Process resting potential of -70 mV Neuron creating polarization high concentration of Outside sodium ions (Na+) positively charged Inside potassium ions (K+) banana : Salt on outside and potassium Like a inside 7 on 8  Effect of Neurotransmitters Excitatory Inhibitory neurotransmitters neurotransmitters _______________ Hyperpolarizes Depolarizes ____________ neuron neuron I make it more negativel (making less negative) ____________ Increases _____________ Decreases likelihood of action likelihood of action potential potential 9  Action Potential _____________________ Stimulated by axons terminals Dendrites of 1000’s of other neurons All of the depolarizations & Summation hyperpolarizations added up If the resulting summation Threshold reaches reaches -55 mV (threshold), an AP will fire 10  Action Potential Electrical part of process is the Action Potential Shift in voltage - Resting = -70 mV from minus to plus - depolarization Shift to +40 mV If threshold reached – AP will fire at All or none Law max intensity If threshold not reached – no AP Refractory After AP, neuron has to ‘recharge’ period during which neuron cannot fire again 11  Myelin ________________ Sheath Fatty insulation layer derived from glial cells – insulates axon from electrical activity – acts to increase rate of transmission of signals – ______________ Nodes of Ranvier – gaps in myelin; allows AP to jump 12  Multiple Sclerosis _________________________ – neurological disorder characterized by demyelination of axons – immune system attacks myelin sheath 13  Specialized Transmitter Systems 100-150 different neurotransmitters – More substances suspected! Each has a different effect – Specific excitatory or inhibitory effect – Several linked to specific psychological phenomenon 14  ADNGSE After dinner , nights get so enjoyable Acetylcholine ________ Dopamine ________ __________ Nor-epinephrine Ach Motor Voluntary Control movement Stress Learning & Reward & Response Memory Pleasure Parkinson's Depression Memory loss · Schizophrenia Stress Paralysis/ · Spasticity · Addiction Panic · Drugs disorders 15 ________ GABA Serotonin ________ Endorphin ________ Mood, sleep, Pain relief Anxiety and eating, motor control Euphoria arousal · Anxiety Depression, Pain · Alcohol Sleeping & insensitivity · Epilepsy eating Pain disorders hypersensitivity 16  Turning Neurotransmitters ‘Off’ As long as NT is in the synapse, it is “active” – activity must somehow be turned off Reuptake ____________________ – scoop up and recycle NT ____________________– Enzymatic degradation a NT is broken down by enzymes Adapted from Iacono & Koenig, 1983.  Unlocking the Brain’s Secrets Lesion _______________ Techniques Researcher can produce brain damage destroying tissue with electricity, cold, heat or chemicals Study consequences Typically performed on animals, must wait for accident or disease for human lesions part of the brain · Turning off a certain 18  Unlocking the Brain’s Secrets Electrical Stimulation ________________________ Dr. Wilder Penfield (MNI) – Stimulated parts of cortex with mild electrical current Mapped motor & sensory areas; areas for smell, touch etc. Turning parts · of the brain on 19  Unlocking the Brain’s Secrets Electrical Recording (EEG) Electroencephalogram – ___________________ Records electrical activity of thousands of neurons Some EEG patterns correspond to wakefulness & sleep 20  (MRI) Magnetic Resonance Imaging __________________ Method for studying body and brain tissue; uses magnetic fields Provides clear, 3D images Functional MRI (fMRI) ____________________ – Measure of brain activity – Measures changes in blood flow during tasks  Transcranial Magnetic Stimulation (TMS) _______________________________ Involves delivering a large magnetic current through a wire coil on a person’s head Used to: – ‘activate’ motor responses – temporarily ‘inactivate’ an area of the brain – treat depression 22  Divisions of Nervous System Central Nervous Peripheral Nervous system System Connects CNS with Brain and Spinal muscles, senses, Cord internal organs 23 General Layout of the Nervous System Peripheral Nervous System Somatic NS. Autonomic N S. Somebody  Somatic Nervous system _______________________ Interacts with external environment Bringing info in from the senses and carrying motor output to muscles Autonomic Nervous System _______________________ Controls the automatic functions of the body, regulates internal organs – 2 branches: sympathetic & parasympathetic ↓ ↓ fight or flight rest & digest Neuroanatomy Medulla _____________ – Heart rate & respiration – Throughfare for sensory info – Damage? ↳ Death Pons (bridge) _____________ – Sleep; dreaming 26  Cerebellum ____________________ – “little brain” – Muscle coordination – Learning, memory Alcohol disrupts movement- control functions Damage? - uncoordination 27  Reticular formation - _________________ ‘the Gatekeeper’ arouses cortex and screens incoming information Many general anaesthetics work here Damage? ↳ Coma, Vegitative State 28  ___________ Thalamus Receives sensory information and sends them to appropriate areas of the cerebral cortex. Like a _____________ Switchboar Controls where everything goes Damage? ↳ Trouble understanding things ↳Confused Hypothalamus Involved in the the 4 F’s - Feedling - Fleeing - Fighting - Mating behaviour (fucking Causes the release of hormones from _________ pituitary ________ gland (dangles beneath hypothalmus)  Basal Ganglia _____________________ – Voluntary motor control – Parkinson’s Disease - dopamine neurons here degenerate & die resulting in tremors and inability to initiate movements Wanting to do physical actions Limbic System ___________________ – Processing emotions & memories Who you are Limbic System Hippocampus ________________ – Forming & retrieving memories Amygdala _______________ – Organizes emotional responses - especially aggression & fear – Plays important role in anxiety and depression ______________ Nucleus Accumbens – Linked to effects of drugs, addiction, rewards tansa action in this part 32  Cerebral Cortex - The Crown (outside of brain) 75% of area lies within folds (fissures and sulci) 4 lobes: (F POT) - Frontal __________________ – Emotion, planning, creative thinking and motor cortex Parietal ________________ – Body sensations ________________ Occipital – Vision ________________ Temporal – Auditory, certain types of memory 33  Frontal lobes Constitute 3.5% of cerebral cortex in cats, 7% in dogs, 17% in chimps, 29% in humans Self-awareness; planning; initiative; responsibility; emotional experience Prefrontal ______________________ – Seat of executive functions – Goal-setting; judgment; planning; impulse control outbursts - Controlling yourself , stopping Damage? ↳ Phineas Gage (pole thre brain) 34  Motor & Somatic Sensory Cortex Controls Muscles ↑ motor cortex Left side of brain Left side of controls controls right side voluntary movements of the right side of body , of body Vice Versa 35  Speech ________________ Wernicke's area Comprehension of Speech Temporal Lobe ________________ Broca's area Frontal Lobe Production of Speech ACTIVITY 37  Left Brain - Right Brain Hemispheres connected by _______________ corpus callosum 38  Split Brain Experiments Sever corpus callosum hemispheres no longer communicate Visual info process in opposite side of brain Right visual field - processed in left hemisphere Left visual field - processed in right hemisphere 39  Two minds in one body? Anatomy of visual system made split brain experiments possible Roger Sperry’s experiments 40  Left Brain - Right Brain Hemispheres connected by corpus callosum Lateralization - Functions localized in one hemisphere Left Left Hemisphere Right Hemisphere Verbal Positive Verbal , logical Spatial relations , abilities melodies Positive emotions Negative emotions 41  Lateralization of Language Right-Handers 95% have left hemisphere language dominance (approx. 40 % ) 50% have left hemisphere language dominance Left-Handers 25% have right hemisphere language Lapprox. 10 %) dominance 25% have language functions in both hemispheres 42  Plasticity of the Brain Neural Plasticity change in structure & function ______________= Greater plasticity early in life 1-2 year old has 50% more synapses than adult – Unused, weaker synapses deteriorate In adults neurons can modify themselves structurally or biochemically Recovery of function Neural reorganization – ________________ 43  Case Study: Jody Miller - Epileptic Seizures at 3yrs old - Coming from right hemisphere - Ben Carson (Surgeon - hamispheral sectomy - Lost control of left side of body side of brain - Removed right allowed for her to continue functioning left brain plasticity , - Started controlling 44 right brain functions Reminder – Complete Chapter 3 Quiz on Connect! 45