Psych 100 Week 1-4

Psychology

Psychology is the study of behavior and mental process

Mental Processess

private thoughts, emotions feelings and motives

Scientific study

approach to gaining knowledge using systematic observation

Linking to research

The knowledge gained from psychological research can be used to assist people

Link to practice

• Practicing Psychologist should only use techniques and procedures that are effective as shown by research

• Knowledge gained from practice can suggest new research

Areas in Psychology

• Clinical Psychologist - evaluation, diagnosis, treatment - focus on mental health conditions - mild to sever and complex

• Clinical Neuropsychologist - evaluation, diagnosis, treatment - focus on clients with brain disorders - memory, attention, language

• Educational and Developmental Psychologist - evaluation, diagnosis, treatment - developmental and educational difficulties across the lifespan

• Counselling Psychologist - (Career, Marital, Greif) - conflict resolution, can diagnose some disorders - mainly people with everyday problems

• Forensic Psychologist - within legal and justice systems - assessment, evaluation, interventions

• Organisational Psychologist - business, industry, government - recruitment training, career development, increasing productivity

• Health Psychologists - working to promote good health or assist those who already have health problems - working with individuals or public health programs

• Community Psychologist - promote mental health at community level - focus on communities at risk

• Sport and Exercise Psychologist - works to improve performance of athletes

Where does knowledge come from?

• Empiricism (Aristotle, John Locke)

• All humans came into the world as blank slates

• All behavior is learned from environment

• Nativism (Descartes) contrasts with empiricism

• Born with innate knowledge common to all humans independent of personal experience

Structionalism

• Wundt made psychology and independent discipline

• Medical doctor

• Wundt believed psychology should be a science

  • Scientific approach

  • Controlled observations - introspection and reaction times

  • Wanted to explore consciousness (awareness of experience)

• Wundt believed that sensations and feelings were key

• Identify elements of consciousness  - how they combine

• Titchener (1892) coined the term structuralism

• Examine how elements of consciousness are related (sensations, feelings, images)

• (basic elements of consciousness through introspection)

Limitations Structionalism

• Not possible to directly observe workings of the mind

• Subjective experiences

• Thus developed systematic introspection

• Rigorous descriptions

• Selected sensation and perception as seemed easier to establish the elements

• Taste: salty, bitter, sour sweet

Functionalism

• James (1872) Investigation of function of consciousness rather than structure

• Believed that structuralists missed the point of consciousness

• Flow of thoughts

• Explored the formation of habits and self (personality)

• Need to understand overall goal rather than how parts combine

• Darwins natural selection was influential - why does trait persist

• Therefore, what is the adaptive value of psychological process

• Led to more research topics

• Interaction with environment

• Individuals difference

• Allows human behavior to be explored

  • explain psychological processes in terms of the role and there function

Limitation

• Immediate conscious experience is the focus

  • Introspection

• Many psychologists believed introspection was not scientific

  • Subjective

  • Cannot test accuracy

  • Iimitated population who can be participants

Freud additional

• Freud (1900) attempted to treat mental disorders

• Psychanalysis for fears and anxieties

• Led to the notion of unconsciousness

  • Thoughts, memories and desires that drive behavior

• Believed childhood experiences are key - stores

• Highlighted that possibility that we are not masters of our own mind

• The method of psychodynamic approach seeks to interpret meanings

• Infer underlying wishes

• Interpretation of dreams and fantasies

• Psychodynamic psychologists rely on clinical data to support their theories

  • Subjective interpretation

  • In dept observation of one or two people

Behaviorism - Watson

• Psychology is the study of observable behavior

  • Behavior is seen as any overt response

  • Thought to be strengthening scientific approach

• Allows objective replication

• Redefined psychology

• No reference to consciousness or unconsciousness

• Studied the link between behaviors and the environment

• Stimulus response psychology

• Behavior based on previous experience (rewards and punishments)

Skinner

Skinner (1953) supported strict behaviors

• Believed in mental states, but argued not necessary to explain behaviors

• Reinforcement and punishment

Critics

• Critics viewed behaviorism as de-humanising and lacking free will

• Psychoanalysis to have a pessimistic view of humans

Humanism

• Rodgers (1902-1987) behavior relates to our sense of self

• Maslow (1908-1970) Humans have a desire to reach their potential

• Humanistic Psychology: focus on unique qualities of humans allowing for freedom, personal growth and self awareness

• Driven by the desire to reach your full potential

• Focuses on persons unique perspective and experience

  • Not powerless victims, strive to reach potential

  • Goals influenced by experience

  • Personal centered

  • Therapist is supporter rather than the judge

Maslow Heirachy of needs

• self actualisation

• esteem needs

• belongingness needs

• saftey needs

• physiological needs

Cognitive Psychology

• Psychology has a renewed interest in consciousness (1950s/1960s)

• Cognitive revolution

• Cognition: processes in acquiring knowledge

• Piaget: How Children's cognition develops

• Chomsky: How language develops

• Led to people arguing psychology should explore the way people think

Information Processing Model

• Input

• Transformed

• Stored

• Retrieved

• Response

Biological Psychology

• Psychology observed relationships between physiology, behavior and thoughts

• Brain stimulation

• Brain injuries

• Biological psychology argues that much behavior can be explained by brain structures and chemical processes

• Hemispheric specialisation

• Advances in technology have supported research

• Helps understand typical and atypical brain activity

• Increase in understanding of the link between biology and behavior

• Chemicals in the brain relate to psychological disorders

Evoultionary Psychology

• Due to the rise in behaviorism, evolutionary psychology was ignored until recently

• Explanations offered are often deductive - begin with a characteristic

• Explain how this may have supported natural selection

• Why behaviors have adaptive value over time

• Natural selection favors behaviors that will increase reproductive success

• Assumes that we are born with mental processes to guide behavior

• Acquired through natural selection

• Helps solve adaptive problems

• Language - communication

• Finding mate - reproductive success

Positive Psychology

• Seligman believed psychology to be negative

• Much attention towards disorders with little attention towards building positive aspects of life

• Positive subjective experiences: happiness, love

• Positive individual traits: personal strengths

• Positive institutions: supportive communities

Timeline

• 1879: Wundt first psychological lab

• 1860: William James - Structionalism, Functionalism

• 1900: Freud - Psychodynamic approach

• 1910-1920: Watson, Pavlov, Skinner Behaviorist approach

• 1950: Cognitive revolution - Humanistic

• 1980: Biological and Evolutionary

• 1990: Positive Psychology:

• Now Eclectic mix

Culture and Psychology

• Culture plays a large role in modern psychology

• Shared values, customs, beliefs

• Obvious characteristics: race or social class

• Other characteristics: religious or political beliefs

• Culture influences all aspects of behavior and mind

• Until recently Psych explored the environment and an individual person

• Universal laws of group behavior

• Cross cultural differences?

 

Culture influences out behavior as the environment influences our social and cognitive development

• Vygotsky: thoughts originate from social interactions

• Culture affects psychological principles

• Need to consider how an individual is within their social and cultural context

Boundaries and Borders of Psychology

• Biopsychology = examines the physical basis of psychological phenomena such as motivation, emotion and stress

• Sociocultural perspective =  a modern approach to psychology that emphasises social interaction and the cultural determinants of behavior and mental processes

• Cultural and cross- cultural psychologists = each adopt and approach content and context of a culture rather than absolute universal truths are important in the study of human behavior

Parts of Brain oringinal theory

• 1839 Dr Marc Dax suggested lesions in left side of brain were associated with language disorders

• Paul Broce (1824-1880) discovered brain injured people with lesion in front section of left hemisphere could not speak but could comprehend language

• Carl Wernicke (1848-1904) showed that damage behind Broca could lead to another kind of aphasia - could speak fluently and follow grammar but could not understand language or speak in a way that others could understand

Wundt theory

• Methods included introspection - involved looking forwards and reporting on ones consciousness experience

• Not like introspection of philosophers - speculated freely

• Wundt trained observers to report verbally everything in their mind when presented with stimulus or task

• By varying objects  Wundt concluded that the basic elements of consciousness are sensations (colours) and feelings

• These elements combined to make more meaningful perceptions eg a face

Structionalisn vs Functionalism

• Wundt's student Edward Tichener (1867-1927) advocated using introspection with the hope of devising the elements of human consciousness

• Because of his interest in the structure of human consciousness - he created structuralism

• Unlike Wundt, Titchener believed that experimentation was the only appropriate method and concepts like attention implied too much free will 

• Experimental psychologists post Tichener went further, viewing the study of consciousness as unscientific because data was sensation and feelings , could not be observed except person reporting

• Instead of focusing of concepts in the mind functionalism emphaises the function of psychological processes that helped individuals adapt to their environment

• Founder of functionalism William James (1842-1910)

• James believed that knowledge of human psychology could come from many sources including introspection and experimentation

Key propositions psycoanaytic theory

• Aspects of personality emerge in childhood

• Mental representations of self, others and relationships guide peoples interactions

• Mental processes including affective and motivational processes operate simultaneously - individuals can have conflicting feelings outside awareness

• Personality developments involved learning to regulate sexual and aggressive feelings but moving from immature and dependent to mature and independent

• Life is unconscious

Origins of Cognitive Perspective

• Comes from Greek Philosophers like Descartes, Plato

• The mind itself generated knowledge

• Aristotle emphasises the role of experience in generating knowledge

• Locke proposed that complex ideas arise from mental manipulation of simple ideas

• Behaviorists reject Descartes view of an active reasoning mind

Ethology, Socicobilogy and Evolutionary Psychology

• E.O Wilson 1975 invented sociobiology which explores possible evolutionary and biological bases of human social behavior

• Sociobiologists and evolutionary psychologists propose that genetic transmission is not limited to physical traints

• Parents pass on behavioral and mental tendencies

• Behavioral genetics - examines the genetic and environmental bases of differences amount individuals on psychological traits suggest heredity is strong in determining personality and intellectual skills

• Central to evolutionary psychology is the notion that the brain, eye, heart  as evolved for survival and reproduction

Steps in a scientific method

Genrelisability

• Interval validity = measure what you intend to measure

•  External validity = can be generalised outside the lab

Scientific method advantages

• Clear and precise

• Operational definitions so we know exactly what is being discussed

• Intolerant of error

• Scientists test their ideas

• Scientists scrutinise other peoples research

• Objective data must be used

Reliability and validity

• Reliability = closeness of repeated measurements to each other

• Validity = closeness of a measured value to its true value

Descriptive methods

• Simply describe the phenomena

• Benefit = can explore questions which cant be looked at experimentally

• Negative = cannot determine cause and effect

Naturalistic observation

Naturalistic observation: In depth observation in a naturalistic setting

• If someone knows they are being watched they may act differently

• Be a participant- observer

• Only describes behavior and cannot determine cause and effect

• researcher bias

• limited generalisability

Case Study

Case Study: in depth investigation of one person, or a small group

• Good when examining rare disorders

• Techniques include

  • Interviews

  • Psychological testing

• Clinical Psychologists and clinical neuropsychologists commonly conduct case studies

 

Limitations:

• Need to compare multiple case studies to look for commonalities

• obsserver bias

• low sample size

Survey

Survey: Questionnaires or interviews gather data about specific topics

• Look for relationship between the data

• Surveys can obtain information on difficult to observe behavior

 

Limitations:

• Less willing to complete surveys due to identify theft concerns

• Self report data - social desirability affect

Correlational research

 

Correlational Research: Exploring how much two variables are related

• Correlate: extent that the variables are co-vary

• Positive correlation: as ones increases, so does the other

• Negative correlation: as one increases the other decreases

 

Limitations:

• Correlation to not imply causation

quasi experimental design

differ naturally, but matched on other charcteristics

• cannot provide cause and effect

Conducting experiment includes

• Hypothesis

• Operationalising variables

• Developing standardised variables

• Developing standardised procedures

• Selecting and assigning participants

• Applying statistical techniques

• Drawing conclusions

• Limitations include difficulty bringing complex phenomena into a lab

Characterisitcs of quaitiative resarch methods in psychology

• Qualitative research involved deep dive into research topic

• Has a holistic view - takes inductive approach and is in naturalistic settings

• Key theoretical perspectives that underpin qualitative research include:

  • Positivism

  • Interpretivism

  • Critical theory

• Epistemology examine the nature of knowledge using three key approaches - objectivism, constructionism and subjectivism

How to evaluate study critically

• Ask questions abut theoretical framework, sample, measures and procedures, broader conclusions and ethics

• Experiment or study is replicatable is it can produce same results when repeated

• Critical thinking is essential in psychological research - making logical and rational assessment of information

Quantitaive research in psychology

• Quantitative research involved using experiments to gather data that can be statistically analysed

• Normal process is:

  • Carry out survey

  • Tabulate data

  • Analyses it using standard statistical packages and protocols

  • Draw conclusion based on hypothesis

• Normally based on large sample - representative

• Research has high reliability

• Analysis of the results is more objective than qualitative research

• 3 main goals of psychological research:

  • To describe, predict and explain or understand behaviour and mental processes

• Some studies require attempts to describe or classify behaviours and mental processes through observation

• Scientific method represents standardised procedures of research used to gather and interpret objective information

The scientific method

• observation and litrature reiview

• testable hypithesis

• research design

• data collection and analysis

• publication

• theory development

Reliability

• Reliability refers to measures ability to produce consistent results

• Reliable psychological measures should not fluxuate based on presence of random factors

• Retest Reliability = refers to the tendency of a test to yield similar scores for the same individual over time

• Internal Consistency = a measure is internally consistent in several ways of asking the same question yield similar results

• Interrater Reliability = if two different interviews rate an individual on some dimension both should give person similar scores

Validity

• To ensure validity of a psychological measure - researchers conduct validation research

• Validation = demonstrating that a measure consistently relates to some objective criteria or to other measures that have already demonstrated validity

Experimental research

• Psychology takes a scientific approach to research using empirical methodologies to gain knowledge

• Empirical methodologies involve a process where hypothesis are tested - experiments, observations

• Involved rigorous testing of a theory

• Description = summarising data your research has produced in a way that makes events and relationships understandable

• Prediction = using outcome of research to identify what would happen in future

• In experimental research some aspect is manipulated and examine response

• Experimental methods establish causation - one variable leads to predicted changes in anothe

Steps in conducting an experiment

• frame hypothesis

• opertionalising the variables - turning abtsract concept into varaibles defined by actions

• developing a stndardised procedure

• selecting and assingming participants

• applying statistical techniques to the data

• drawing conclusions

Advantages and Limitations of experimenter research

• Advantages:

  • No other method can determine cause and effect so unambiguously

  • Experiments can be replicated to see whether the same findings emerge with different sample

• Limitation:

  • Many complex phenomena cannot be tested

  • Researchers can never be certain how closely phenomena in a lab parallels real life

Aims qualitive research

• Crotty 1988 4 elements

  • What methods do we propose to use  - how to collect data

  • What methodology governs out choice and method - how to Analyse data

  • What theoretical perspective lies behind methodology

  • What epistemology informs this theoretical perspective - branch of philosophy associated with nature, origin and human knowledge

Different types of research processes

• Positivism = perspective that suggest a straightforward relationship between world and out understanding of it - favors objective research

• Interpretivism = concerned with subjective issues like feelings, values, experiences and meanings

• Critical theory = requires the researcher to delve below the surface to uncover the real structure of the material world, concerned with power expression in society e.g feminism

• Objectivism = contends that phenomena exist independently of our beliefs or consciousness of them

• Constructionism = there is not one objective knowledge

• Subjectivism = meaning is assigned to phenomena by the observer - subjective and individual

Approaches to qualitive research

Aspects to designing a qualitative study

• Not that different to quantitative study

  • More general approach to the topic

  • Considerations of how much literature to include

  • Actual format of the study

  • Assumptions and philosophical issues that guide the study

• Janice Morse (2000,2016) what qualitative research should:

  • Be systematic and rigorous

  • Be strategic and sensitive to contextual demands

  • Be reflexive - keep track of engagement in the research and knowledge production process

  • Involve small number of participants but does not mean it is to remain limited

  • Conducted in ethical manner and sensitive to social, cultural and political context

Critical Thinking

• Involves carefully examining and analyzing information to judge its value

• Making a logical and rational assessment - assessing strengths and weaknesses

• Skepticism = questioning assumptions to conclusions and analyzing whether the evidence presented supports the results

• Objectivity = taking an impartial or disinterested approach

• Open mindedness = considering all sides of an issue

Fallacies in arguments

• Straw man = authors deliberately attacking an opposing argument to strengthen their own argument

• Appeals to popularity = refers to the fallacy that a popular and widespread argument is true

• Appeals to authority = refers to the fallacy that an argument must be true because the authority of the person making it

• Arguments directed to the person = refers to the approach in which authors try to strengthen their own argument by attacking the authors alternative arguments

Internet and Psychology research

• Benefits:

  • Online sources mean easy access to research and data on topic

  • Recruitment for participants

  • Cost and efficiency benefits

  • Automation of data entry

  • Having people do surveys from home - more comfortable

• Challenges:

  • Information can be questionable

  • Internet connectivity is not universal

  • Reduced control of researcher

  • Data is easier to be shared - ethics

  • Completing surveys at home can make it difficult to determine harm

  • Difficult for debriefing

Leisons vs Modern

• Lesions

  • Brain injury

  • Electrical stimulation

  • can only be certain one area has been damaged

  • limitation include few participants

• Modern

  • EEG

  • TMS

  • Brain imaging

    • PET, CT and MRI/FMRI

Electroenphalography (EEG)

• A device that detects amplified and record electrical activity of the brain

• Electrical activity can be recorded

• Measure clusters of brain activity over time

• Use of electrodes

• Line tracing aka brain waves

• Used to understand mental activity

• Diagnosis of brain damage and epilepsy

• Can be used to identify sleep stages

Transcranial Magnetic Stimulation (TMS)

• Magnetic coil over persons head

• Virtual lesions

• Painless and non-invasive

• Limitations

  • Cannot be used for deep areas of the brain

• Possible use as intervention, ED, GAD

Computerised tomography (CT) scan:

• X ray of the brain

• Computer combines multiple images

• Horizontal slice

• Least expensive

• Can be used to explore structure and abnormalities

Positron emission tomography (PET) scan:

• Explores function

• Maps activity over time

• Radiative chemicals illustrate blood flow

 

Magnetic resonance imaging (MRI) scan:

• Magnetic fields and radio waves

• Brain structure

• 3D image with high resolution

Function magnetic resonance imaging (fMRI) scan:

• Monitors blood flow and oxygen use

• Function

• Great precision

Statistics

• make sense and intrepret data

• There are different ways to use statistics to inform decisions

• Descriptive statistics: condense the data to make it useful

• Inferential statistics: get more in depth

  • Testing scientific hypothesis

  • Calculating effective sizes

Measures of centre vs spread

• Median: Score that falls in the middle, middle point when data in order

• Mean: average, sum of data, divide by number of data points

  • Most useful

  • Sensitive to outliers

• Mode: most frequent score

• Centre isn't everything

 

Measures of spread:

• Range

• Standard deviation

• Variance

Stratagies of inquiry

• Grounded theory

  • Generates a new theory

• Phenomenology

  • Understanding lived experienced

• Ethnography

  • Description and interpretation of cultural/social group

• Case study

  • In depth study of single/few cases

• Action research

  • Research + action

Research animal vs humans

• For humans

  • Treated with respect

  • Voluntary participation

  • Should not be harmed

  • Debriefed after deception

  • Confidentiality

  • Informed consent

 

• For Animals

  • Harmful procedures should not be used unless the end justifies the means

  • Live in decent conditions

Code of Ethics Principles

• Respect for rights and dignity of people

• Informed consent, privacy, confidentiality, access to own information

• Propriety

• Competence and professional responsibility

• Integrity

• Reputable behavior, impartial, non-exploitative

Flaws in research

• Sampling bias

• Placebo effect

• Distortion in self- report data

• Experimenter bias - expectations

Importance of replication

• Replication: repeating a study

• Can lead to contradictory results

• Science works to explain these contradictions

• Meta- analysis = combing results from many studies to test genrelisability of studies

What is a neural impulse

• How do neurons communicate with one another

• Neural impulse is an electrochemical reaction

• Electrically charged molecules (ions) inside and outside neuron

• Positive: Sodium and Potassium

• Negative: Chloride

• Flow across membrane at different rates

• More negative inside the neuron

• Resting potential: stable negative charge - inside neuron

Resting Potential and action potential

• Channels allow ions to past through cell

• 70 mv is resting potential - negative

• Changes in concentration of ions

• Increase sodium - more positive depolarization

• 30mv is peak in a reduction in charge of cell - repolarization

• Charge of cell can drop below resting potential - hyperpolarization

• Absolute refectory period - neuron cannot be reactivated

• Relative refectory period - difficult for cell to have another action potential - needs a strong action potential

 

Action Potential Propagation

• How does the neural impulse move through the neuron

• When activated positive ions, rush into the neuron - sodium

• More positive

• Triggers action potential along the axon

• The channels then close and resting potential is restores

• Absolute refractory period: minimum time before another action potential can begin

• 1 or 2 milliseconds

• Relative refractory period - heightened threshold

Process

• Presynaptic neuron  start

• Synaptic cleft

• Action potential from cell body through axon

• Vesicles contain neurotransmitters will fuse

• Then neurotransmitters will be released

• Travel to receptor sites then it binds and can be absorbed

Postsynaptic potential

• Postsynaptic potential (PSP) voltage change at the receptor site caused when neurotransmitter and receptor combine

• Vary in size - increase or decrease the change of neural impulse in the receiving cell

  • Excitatory PSP: Positive voltage shift

  • Inhibitory PSP: Negative voltage shift

• Lasts only milliseconds

• Neurotransmitters drift away and enzymes may break them down

• Neurotransmitters can undergo reuptake

Neurotransmitters

• Bind to receptor sites

• May be broken down by specific enzymes in synaptic cleft

• May undergo reuptake at pre-synaptic button

Types of Neurotransmitters - Small Molecules

• Acetylcholine:

  • Memory, movement

  • Malfunction - Alzheimer's disease 

• Norepinephrine:

  • Mood, sleep, learning

  • Malfunction - depression

• Serotonin:

  • Mood, appetite, impulsivity

  • Malfunction - depression

• Dopamine:

  • Movement, reward

  • Malfunction - Parkinsons disease, schizophrenia

Types of Neurotransmiiters: Amino Acids

• GABA:

  • Depressant

  • Sleep, movement, regulation of anxiety

  • Malfunction - anxiety, Huntington's disease, epilepsy

• Glutamate:

  • Excitatory

  • Memory, learning

  • Malfunction - damage after stroke

Other Neurotransmitters

• Endorphins:

  • Pain control

  • Also linked with mood elevation

  • opium elevae mood

• Nitric Oxide:

  • Memory

Agonist and Antagonist

• Receptor sites can be fooled by other chemicals

• Agonist: chemical that mimics the action of a neurotransmitter

  • Produces the same effect then the original neurotransmitters - e.g nicotine

• Antagonist: opposes the action of a neurotransmitter

  • Block the neurotransmitter by occupying its space

  • E.g curare stops muscles moving

Endocrine System

• Endocrine system also relays messages

• Secretes hormones into bloodstream

  • Binds to many receptor sites throughout the body at once

• Hormones often similar to neurotransmitters

• Adrenaline and Noradrenaline = epinephrine and norepinephrine

  • Physiological arousal vs anxiety and fear arousal

• Oxytocin:

• Neurotransmitter = nurturing behaviors

• Hormone = breast milk production

Components of Endocrine System

• Pituitary gland: pea sized structure in the brain

  • Master gland

  • Releases many hormones

  • Connected to CNS

• Thyroid Gland: found in the neck

  • Growth and metabolism hormones

  • Energy levels and mood

  • Underactive thyroid = depression and sluggish behavior

  • Overactive thyroid = increased metabolism

• Adrenal Glands: above the kidneys

  • Adrenaline during emergencies

  • Cortisol

• Gonads: located in testicles or ovaries

  • Sexual development, sex drive and secondary sex characteristics

  • Testosterone vs estrogen/progesterone

Action Potneial and Gradient

• Electrical gradient

  • Difference in electrical charge between inside and outside the neuron

  • Maintained by cell membrane

  • More positive ions one side and more negative on the other side

• Resting potential (resting neuron)

• Neuron not firing, but is ready

• Polarization - inside negative charge outside positive charge

How does action potneial actually work?

• Ion channels open in membrane (wall of the neuron)

• Positive ions (Sodium Na+) rush into neuron

• Once charge reaches (+30/40 millivolts)

• Original ion channels (Na+) close

• Other ion channels open (Potassium K+

  • Positive ions leave the neuron

• Charge goes below resting potential -90mv ion channels close Na- K pump returns to resting potential

• Change in electrical charge in one areas causes change in electrical charge in next area - as impulse moves along neuron

• Threshold of excitation, stimulation needed to cause action potential -50mv

  • Below threshold no action potential

• All or none law

  • Strong stimuli fire more often

Graded Potentials

• Stimulation causes change in the electrical change of the neuron but not action potential

• The change is graded: the amount of change depends on the amount of stimulation

• Change causes change in surrounding areas - does not travel length of neuron

• Change can be:

  • Polarization - increasing the negative charge inside the neuron

  • This makes it less likely neuron will fire action potential

  • Depolarization: decrease in negative charge inside the neuron

  • This makes it more likely the neuron will fire an action potential

Process

• Stimulus causes action potential

• Travels down axon

• Terminal  buttons

• Synaptic vesicles

• Synaptic gap

• Receptor sites on Post Synaptic neuron

• Can trigger action or graded potential

What can neurotransmission trigger

action or graded potential

• Stimulus causes action potential - Action potential travels down axon to terminal button

• NT released

• NT released into synaptic cleft, NT bind to complementary receptors in postsynaptic neuron  dendrites - NT triggers change in action potential or graded potential.

• Triggering action potential = process repeated

• NT released from receptors are broken down or reuptake back into presynaptic neuron axon.

CNS

• Sensory Neurons: transmit information from sensory receptors to the brain either directly or via the spinal cord

• Interneurons: output is received by interneurons, nerve cells that connect other neurons with one another

• Motor Neurons: transmit commands from interneurons to muscles, organs and glands of the body

  • Carry out voluntary and involuntary actionsforebrain, midbrain, hindbrain

  • brain and spinal cord

PNS

• Neurons in the PNS carry messages to and from the CNS

  • Somatic NS - carries sensory information to the brain and motor neurons to direct skeletal muscles

  • Autonomic NS - controls basis life processes like heartbeat and breathing

• Autonomic NS consists of sympathetic and parasympathetic

heritability

Heritability = refers to the proportion of variability among individuals on an observed characteristic that can be accounted for by genetic variability

Characterisitcs of graded potential

• Their strength diminishes as they travel along the cell membrane to the source of stimulation

• Graded potentials are cumulatively if a neuron is depolarized by -2mv at one point on a dendrite and hyperpolarized by -2mv at an adjacent point the two graded potentials add up to zero and cancel each other

Transmission of information between cells

Glutamate

• Glutamate is a neurotransmitter that excites neurons in NS

• Involved in memory, synaptic plasticity, learning

• High glutamate linked with neurodegenerative diseases like Huntington's disease and Alzheimer's

• Neuroimaging and research with mice helps understand knowledge of glutamates activities in the NS - help treat Alzheimer's

Trearment using dopamine

• Treated using L- Dopa chemical that converts to dopamine

• Dopamine cannot be administered because it cant cross blood barrier

• Blood brain barrier results from the fact that cells in blood vessels are tightly packed meaning large molecues cannot enter

• Serves as an adaptive function preventing toxic substances from disrupting neural functioning

• It also rejects medicine that could treat brain disease

• Only small percent of L- Dopa gets past blood brain barrier

• Causes side effects like nausea, vomiting, shortness of breath

• The L-Dopa that does make to brain is used for different purposes

• Can produce disordered thinking

Autonomic NS

• Conveys information to and from internal bodily structures that carry out basic life processes like digestion and respiration

• Consist of sympathetic and parasympathetic

Sympathetic NS

• Activated in response to threats

• Fight or flight

• Stops digestion, diverting blood away from the stomach and redirecting it to muscles which may need extra oxygen

• Increases heart rate, dilates the pupils, caused hairs on body and head stand erect

• Also involved in ejaculation of males

• It is an adaptive function

• Can also be activated when unwanted - anxiety, tremors, sweating, dry mouth

Parasympathetic NS

• Maintain body's store of energy, regulating blood sugar levels, secreting saliva and eliminating aste

• Participates in regulating heart rate and pupil size

• Parasympathetic involved in returning body back to homeostasis after sympathetic NS is activated

Differnet ares of brain - M, H, F

• Forebrain - specialized for sensation at immediate level, small and eventually taste

• Midbrain - controlled for distance stimuli - vision and hearing

• Hindbrain/brainstem - specialized for movement and balance