Post on 03-Jun-2018
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Outline of the unit:Neurotransmitters
Localization of functionHormonesGenetic research
Evolutionary psychology
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Debate
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How does the biological level of analysis
explain behaviour?
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Levels of analysisMicro Level of Analysis - the smallest units of psychologicalmeasure which are within a person (eg. brain waves,
hormones)
Molecular Level of Analysis - units of observable behavior ofa person alone or in a situation (usually small group) (eg.body language, reaction time)
Molar Level of Analysis - the largest units of psychologicalmeasure of a person or people within the context of a largersocial setting (racism, adolescents across cultures)
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Biological Psychologists Use SeveralLevels of Analysis
Levels of analysis range from social interaction down tothe molecular level.
Reductionism breaks a system down into its smallerparts, in order to understand it.
Modern psychologists (goal of IBpsychology) = Interactionist Approach
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Interactionist Approach An approach which does not rely solely on either nature(biological) or nurture (environment), but adopts a moreholistic picture of human behavior used by modernpsychologists
Bidirectional Relationship Biology can affect cognition and cognition can affect biology
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Learning OutcomesPrinciples:
Brain structure influence behavior & cognitive processes
Brain physiology influences behavior & cognitive processes
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Principles of Biological Level of Analysis
1. Behavior can be innate because it is geneticallybased (evolution)
2. Animal research can provide insight intohuman behavior (significant amount of researchis undertaken using animals)
3. Biological correlated of behavior ( (link betweena specific biological factor and a specific behavior)
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Principle humanbehaviour is innate,to a greater or lesser
extent inherited
Method correlational study
Example -Minnesota twin
study (Bouchard etal, 1990)
Charles Darwins Theory of Natural Selection (1859) and
Evolutionary Psychology(Image source: http://darwinday.org/learn-more/about-evolution/)
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Principle animalresearch informsunderstanding ofhuman behaviour
Method animalstudies
Example Martinez andKesner, 1991
Image source: www.animals.nationalgeographic.com/animals/
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Principle biologicalcorrelates ofbehaviour
Method studyusing brainscanning
technology
ExampleDavidson, 2004
Images from wikimedia creative commons and Flickr creative comm
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Communication in the NervousSystem
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Communication in the Nervous SystemLO # 6 & 7
Dendrites
Cell body
Axo
n
DendritesCell body
AxonCellbody
Dendrites
Axon
a Sensor neuron b Motor neuron c Interneuron
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Neurotransmission
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Actionpotential
Vesicles
Neurotransmi
Receptors forneurotransmitSpreading
wave ofdepolarization
DENDRITE
AXON
Synapse
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S y n a p t i c T r a n s m i s s i o n
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Drugs and the SynapseDrugs work by doing one or more of the following to
neurotransmitters:
1. Increasing the synthesis.2. Causing vesicles to leak.3. Increasing release.4. Decreasing reuptake.
5. Blocking the breakdown into inactivechemical.6. Directly stimulating or blocking postsynaptic
receptors.
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Kasamatsu & Hirai (1990) MonkSerotonin Study (Serotonin)
Investigate how sensory deprivation affects the brain
Researchers took blood samples before and after theirpilgrimage.The found increased level of serotonin in the Monks brain. Especially in the Hypothalamus and Frontal Cortex.Resulting in hallucination.
Sensory deprivation triggered the release of Serotonin.Serotonin responsible for Sleep, Arousal level, and Emotions.
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Chemical Messengers in theNervous System
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Types of Neurotransmitters
Serotonin involved in sleep, mood , pain suppression& sensory perception
a) Deficiencies can lead to mood, anxiety, & sleepdisordersb) Many antidepressants enhance effect of serotonin
(SSRI)a) Prozacb) Paxilc) These work by preventing the uptake of serotonin
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Types of NeurotransmittersDopamine emotions, reward
a) Higher than normal levels are found in persons withschizophrenia
b) Low levels causes Parkinsons disease L-Dopa helps to increase dopamine for a while
NorepinephrineCognitive & emotional functions
a) Too low of level associated with depression
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Acetylcholine
a) Low amounts of acetylcholine may play role in Alzheimer's b) Involved in muscle action
1) Botulism prevents release of Acetylcholine2) Curare same effect in preventing release
Types of Neurotransmitters
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Types of Neurotransmittersgamma-amino butyric acid ( GABA )
Main inhibitory neurotransmitter in the braina) Low levels are associated with anxietyb) Valium & Xanax increases GABA has calming effect
Glutamate long term memory major excitatoryneurotransmitter found in 90% of neurons
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Some BIG caveats!1. Causation is an issue!2. Just treating the symptoms3. Hard to pin down direct relationship between
neurotransmitters & behavior4. Aspirin can relieve headaches, but headaches are not
caused by lack of aspirin5. Reductionist
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Chemical Messengers in the NervousSystem
Endorphins :
Involved in reducing pain & promoting pleasure Acts to prolong or shorten the activity of specific
neurotransmitters neuro-modulators
Link between increase in endorphins & pleasures ofsocial contact (attachment)
May be link to pain reducing effects of acupuncture
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Basic information on how the nervoussystem worksIncluded in a lot of Learning Outcomes
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Brain Spinalcord Somatic
PERIPHERALNERVOUS SYSTEMCENTRALNERVOUS SYSTEM
Sympathetic Para-sympathetic
Autonomic
Spinal reflexes:Bypasses brain at
first
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Nervous System
Central Nervous System(brain and spinal cord)
Peripheral Nervous System(neural tissue outside brain and
spinal cord)
Somatic nervous system(sensory and motor nerves,
voluntary)
Autonomic nervous system(internal systems,
involuntary)
Sympathetic division(arousal)
Parasympathetic division(housekeeping)
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The Brain Lateral View
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Dr John Harlow
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AccidentQuick Recovery
Months later: No longer Gage
Before: capable, efficient, best foreman, well-balanced mind After: extravagant, anti-social, liar, grosslyprofane
Died 12 years later
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Localization of function in thebrainThis is where one section of the brain isresponsible for a specific function.
Brocas Areaan area of the left frontal lobe that directs the
muscle movements involved in speechWernickes Area
an area of the left temporal lobe involved inlanguage comprehension and expression
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The Cerebral Cortex Aphasia
impairment of language, usually caused by lefthemisphere damage either to Brocas area (impairingspeaking) or to W ernickes area (impairingunderstanding)
Broca's aphasia: when an individual has problems
producing speech, but is able to understand it. Wernicke's aphasia: when an individual can produce
speech but has problems understanding it.
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Brocas AphasiaIn 1862, showing brain lesions in a stroke patient who could understand language but could not speak(could only say "tan"), he demonstrated that the leftfrontal lobe was responsible for articulation of
speech.
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Sarah Scott - Broca's aphasia casestudy The video on the right is of a British girl from Sarah Scott, who
suffered a stroke at 18 and developed Broca's aphasia as aresult.
There are a series of videos on YouTube, documentingSarah's slow recovery over the course of a number of years. Itmakes for moving viewing at times, but it is a great example ofthe sorts of difficulties that Broca's aphasia can involve.
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Wernickes Aphasia Like Broca, Wernicke 1874 investigated a similar strokevictim. But this time the patient could speak but made nosense. The damaged area was around where the temporaland parietal lobes meet in the posterior part of the lefthemisphere. His findings further revived the localisationist view.
Wernickes aphasics show deficits in languagecomprehension but intact articulation
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The Limbic SystemHypothalamus, pituitary,amygdala, and hippocampusall deal with basic drives,emotions, and memory
Hippocampus Memoryprocessing
Amygdala Aggression(fight) and fear (flight)
Hypothalamus Hunger,thirst, body temperature,pleasure; regulates pituitarygland (hormones)
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Karl Kim and Joy Hirsch (1997)How the brain processes language in bilingualindividuals?1. What conclusions could be reached from this study in
terms of localization of function?2. What could be the advantage of using fMRI in this
study?
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Localization of the Brain functionElectrical stimulation of the nucleus accumbens thepleasure center
Heath (1950) Patient B-19 during a three hour studyadministered 1500 electrical impulses to induce pleasuresensation. James Old
Rats walk across an electricalgrid to push the pleasure lever.they even preferred thesimulation to eating and drinking
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The Nucleus AccumbensStimulation of the neurotransmitterDopamine promotes desireSerotonin promotes satiety and inhibition
Animal studies show drugs increase the levels of DA(dopamine) in the n.a. and lower 5-HT(Serotonin)
Cocaine
NicotineIncreased usage of the drug increases the amount of DA inthe n.a.
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Ethics Animal studies have been used to gain valuableinformation about the nucleus accumbens andaddiction. Animals in these studies suffered and were killed.Find an argument on both sides of the debate about whether it is ethical to use animal research for thebetterment of human beings.
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Each organism contains many neurons , or nerve cells.
Neuronal activity is studied to understand themechanisms underlying behavior.Research can be applied to humans, especially in diseases
of the brain.
Viewpoints to Explore the Biology of Behaviour
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Neurotransmitters and their
Effects on Behaviour
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How environment affects the brainEffects of the environment on psychological process: Jet lag disrupts circadian rhythmsEffects of deprivation of neuroplasticityEffects of environmental stressors on reproductivemechanismsEffects of stress on the immune system
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Neural Plasticity: Behavior CanChange the Brain
Neural plasticity describes the ability of the brain to bechanged by environment and by experience.
This can occur during development as well as in adulthood.Dendritic spines in the brain can change shape in seconds.
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Brain PlasticityCan the brain change in response to the environment?Hubel and Wiesel (1965)
Laboratory experimentRats
Rosenweig & Bennett (1972)Lab experiments with rats
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Rosenzweig & Bennett (1972)Rats in 2 environmentsMeasured the effects of neural develop incerebral cortexGroup 1 : Enrichment (interesting toys) social life too!
Group 2 : Deprivation (no toys)
What were the results?
Brain plasticity
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Environmental influences on neuroplasticity
Impoverished environment
Enriched environment
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Group 1 : Enrichment (interesting toys)30-60 days, then autopsied post-mortem brainsGroup 1 (enrichment) thicker cortex, frontal lobe(thinking, planning, decision making) heavierBrain weight increased 7-10% Number of synapses increased 20% Impoverished rats easy to spotIncreased cerebral thickness.Environmental enrichment canmodify the brain (esp. cerebral
cortex, higher cognitive functioning)
Brain plasticity
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Brain plasticityPlasticity: brains ability to
rearrange the connectionsbetween neurons
Changes that occur in the structure of the brain asresult of learning or experience (adaptation)
High levels of stimulation, numerous learningopportunities, increase in density of neural connections
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Bryan Kolb and Ian Whishaw, 1998 Infant rats given stimulation & touch(holding)Gained more weightDeveloped faster neurologically
Premature babies, the same results(orphans, preemies (Dr. Tiffany Fields)
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Field 2001, Meaney et al 1988 Repeated experiences modified a rats neural tissue
During puberty, those neuralconnections that have not beenactivated by experience will
degenerate awayUse it or lose it!
Application: learninga new skill, newlanguage, love
B i l ti it
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Brain plasticityThe idea that the brain, when damaged, willattempt to find new ways to reroute messages.
Childrens brains are more plastic than adults. Pons 1991 , severed the neural pathways forincoming information from a monkeys arm The sensory cortex that used to receive
this input gradually shifted its functionSimilar studies: 2009 Lorimer
Moseley and Peter BruggerPhantom Body Parts (amputees)(Ramachandran & Mcgeoch, 2013)
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Brain plasticity
New belief: brain is constantly changingthroughout lifespanBrain changes in response to environmental input
(Good or Bad)
True for Phantom LimbHemispherectomy
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Brain plasticityDendritic Branching :Every time we learn something new, the neuronsconnect a new trace in the brainThe dendrites of the neurons grow in numbers
and connect with other neuronsEx: Brain of expert musician has thicker cortex for musicthan non-musicianStudents who study vs. students who dont
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Effects of Cognition on physiologyHumans are able to influence the way the brain functions(pg 47)
Does Meditation change brain activity? Gamma waves linked to higher reasoning
Richard Davidson (2004)8 Buddhist monks, experienced in
mediationControl : 10 volunteers trainedfor 1 week
http://psyphz.psych.wisc.edu/web/News/Meditation_Alters_Brain_WSJ_11-04.htmhttp://psyphz.psych.wisc.edu/web/News/Meditation_Alters_Brain_WSJ_11-04.htm8/11/2019 Bio LOA Intro
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Effect of Cognition?Does Meditation change brain activity?
All participants told to meditate on love & compassionPET scan: ALL monks exper. increase in number ofgamma waves in their brain during meditation(gamma waves have been linked to higher reasoning)2 in the control group
Stopped meditation, gamma waves returned to normalMonks who meditated on compassion more than 10,000hours kept higher gamma waves
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Modern Viewpoint
Neuroplasticity allows the brain toadapt.
Multiple brain areas coordinate tocomplete cognitive functioning.
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Chemical Messengers in the NervousSystemLearning Outcome 7
Hormones The Long-Distance Messengers Bloodstream
1. Secreted by Endocrine glands that affect thefunctioning of other organs
2. Some hormones are similar to neurotransmitters 3. Pituitary Gland Master gland 4. Types of Hormones
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PITUITARYregulates growth;
controls the thyroid,
ovaries or testes,pancreas, and adrenalcortex; regulates water
and salt metabolism
PANCREAScontrols levels of
insulin and glucagon;regulates sugar
metabolism
TESTES (male)affect physicaldevelopment,
reproductive organs,and sexual behavior
HYPOTHALAMUScontrols the pituitarygland
THYROIDcontrols the metabolicrate
ADRENAL CORTEXregulates carbohydrateand salt metabolism
ADRENAL MEDULLA prepares the bodyfor action
OVARIES (female)affect physicaldevelopment,reproductive organs,and sexual behavior
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Chemical Messengers in the Nervous
Systema) Adrenal hormones (Cortisol & adrenaline)
1) Emotions and stress2) Epinephrine (adrenaline), nor-epinephrine, & cortisol (Increases
blood sugar levels)1) Activates sympathetic nervous system ready for action2) Fight or flight3) Stress!
b) Melatonin (regulates sleep cycle)1) Pineal glands regulates biological rhythms2) Some on 24 hour cycle, others less frequently
1) Circadian (sur-CAY-dee-un) rhythm 24 hours2) Controlled by your body clock suprachiasmatic nucleus (SCN)
in the hypothalamus
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Chemical Messengers in the Nervous
SystemSex hormones
1) Androgens (testosterone) testes & ovaries puberty &
sexual arousal male mainly2) Estrogens female menstrual cycle & female puberty3) Effects of these hormones on non-sexual behavior is
still unclear
1) PMS2) Male aggression
Oxytocin : pituitary gland, may promote attachment& trust between people
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Cortisol and MemoryCortisol is a hormoneproduced by the adrenalglands in response to
stress and to restorehomeostasis.Chronic stress may resultin prolonged cortisolsecretion Which can damage theimmune system andimpair memory.
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Newcomer et al (1999)
Experiment on Cortisol andMemory Aim : To investigate how
levels of cortisol levelsinterfere with verbaldeclarative memory.
ewcomer e a
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Experiment on Cortisol and
Memory Procedure: A self selectedsample (through andadvertisement) of 51normal and healthypeople ages 18-30 wasused.Randomized, controlledand double-blind.Three conditions.
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Newcomer et al (1999)
Experiment on Cortisol and MemoryCondition 1: High levelof cortisol (160 mgtablet), was given. Sameas cortisol released in astressful event.Condition 2: Low level ofcortisol (40mg tablet).Same as minor stressfulevent.Condition 3: A placebo
N t l (1999)
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Newcomer et al (1999)Experiment on Cortisol andMemoryResults :
The high level groupperformed worse on verbal memory test thanthe low level group and
placebo group.The low level groupshowed no memorydecrease.
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Newcomer et al (1999)
Experiment on Cortisol and MemoryEvaluationIt was controlled andrandomized so it was
possible to establish acause and effectrelationship.They received informed
consent.Negative effect of cortisollevels was reversible so noharm was done.
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Brain Imagining Technologies
LO #
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Technology in brain researchInvasive techniques procedures used in earlierresearch that produced damage to localized areas.Before and after studies.
Ablation (removal)Lesions (scarring)
Hetherington and Ranson (1942) lesion to the ventromedialhypothalamus in rats
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Modern TechniquesEEGElectroencephalogramBrainwaves study:
SleepEmotionEpilepsy
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Modern Techniques Cont.,PET Positron Emission Topography. Monitors glucosemetabolism in the brainInjected with radioactive glucose
Detects:TumorsChanges such as Amyloid plaque Alzheimer's
Compares normal to abnormal brains:schizophrenia,sex differences Gur et al., (1995) more metabolism in primitivebrain centers controlling violence in men than women.
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Hainer et al , 1988 (pg 102)PET scans, those with higher IQ use less energyto solve problems than low IQ (metabolic rates)Less Effort Hypothesis
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Modern Techniques Cont.,fMRI functional Magnetic Resonance ImagingMagnetic fields and radio wavesThree dimensional view
Most frequently used technologies in bio-psychologicalresearch.Show actual brain activity
and indicates areas of the brainactive when engaged in behavior.
l
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Evaluating Brain scanning
techniquesfMRI is not a natural environment for cognition. Thereis a question of ecological validityThe use of colors may exaggerate the differentactivities of the brain.Brain areas activate for various reasons just becausethe amygdala lights up, doesnt mean that fear isnecessarily part of the response being observed.
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ToK Ethics:Do you think doctors should scan patients to let themknow is they have a predisposition for a mental illness? What effect do you think this would have on the
individual?Could this technology be misused? Does the potentialfor abuse of technology and knowledge mean that itshould not be pursued?