Bio LOA Intro

8/11/2019 Bio LOA Intro

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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.htm


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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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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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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?

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