IB Psych SL Biological Approach

crying on the inside

MRI

imaging device that gives a detailed picture of the brain’s structure

fMRI

scan using magnetic resonance imaging that also shows activity within the brain through oxygenated hemoglobin.

• shows structure and activity in the brain

PET scan

• tracer injected swallowed or inhaled

• When active, increase in blood flow gives brain more oxygen

• used to create images of the brain

Nueroplasticity

ability of neural networks in the brain to change through growth

• maguire,

Dendritic Branching

the process by which new neurons are formed in the brain.

• maguire

synpatic pruning

a process that eliminates extra synapses that are no longer needed

• maguire

nuerotransmitter

chemical messengers in the nervous system that transmit messages between nuerons

acetylcholine

nuerotransmitter related to memory and muscle movement

• excitatory nuerotransmitter which increases the chances of nuerons firing

• Antonova

Love Cocktail (Fisher)

Theory that dopamine, serotonin, and norepinephrine play a role in motivation for romantic relationships.

Hormones- Testosterone

Hormone related to risk taking and mating

• significantly higher rates of testosterone in men.

• Ronay Von Hippel

Potential Pheromones

chemical substance released into the environment an an animal

• affects behavior of physiology of others of the same species

• under debate whether or not humans have pheromones

• MHC- hormone produced through sweat that is a possible pheromone

• Wedekind

Kendler

Biological/ Abnormal

Aims:

• determine heritability of MDD in swedish twins

• Determine if there are significant gender differences in the heritability of major depression

• determine if there is evidence of genetic and environmental factors of MDD

Procedures

Research uses identical (monozygotic) and fraternal (dizygotic) twins from Sweden

Results:

• concordance rates for MDD significantly higher in women than men

• significantly higher in monozygotic twin vs dizygotic twins

Diathesis-stress theory of depression

predicts that an individual’s reaction to stressful events depend on their genetic make-up.

• Caspi

Caspi

Aim- determine if there is evidence for a gene-environment interaction for a mutation of 5-HTT (serotonin transporter gene)

Procedures

• Correlational study

• New Zealand 26-year olds

• Split into 3 groups: 2 short alleles, 1 short 1 long, 2 long

• Filled out a stressful life events questionnaire about the frequency of certain stressful life events

• Assessed for depression

Results

• Those who inherited one or more short alleles demonstrated more symptoms of MDD

• Strongest for those with three or more stressful life events

Wedekind

• “Sweaty T-shirt Experiment”

Aim: investgating mate preference based on genetic makeup

• evolutionary aim: studies whether females can identify males who had a genetic makeup which would boost the immune system of potentional children when combined with their own

Procedures

• Men were asked to sleep with a T-shirt for 2 nights and keep it in a plastic bag

• Women were asked to rate the smell fo the mens t-shirts based on attraction

Results

• showed women preferred the odors of men with an immune system different than theirs

Antonova

Aim: see if scopolamine (antagonist for acetylcholine) affected hippocampal activity in the creation of spatial memory.

Procedures:

20 Healthy males, double blind

• either injected with scopolamine or a placebo

• Put into an fMRi where researchers scanned their brains while the participants played complex virtual reality games

Results:

• found that participants injected with scopolamine demonstrated a significant reduction in hippocampal activity

HM

• Localization/ Methods of Brain Study

Aim: better understand the role of the hippocampus

Procedures: Case study conducted after HM had his hippocampus removes.

• Method Triangulation: use of one or more research method

• - studied memory and motor skill tasks

• IQ testing (Psychometric testing): results above average

• Observations, interviews, cognitive testing

Results: the hippocampus is in charge of converting memories and experiences from the short term to the long term memory (localization)

Experiment

researcher manipulates an independent variable and measures its effect on a dependent variable

• Participants are randomly allocated into groups

Quasi Experiment

Researcher manipulates an independent variable and measures its effect on a dependent variable

• participants are assigned to condition based on pre-existing traits

Natural Experiment

Uses a pre-test/post-test design but does not manipulate independent variable

Questionnaire

series of questions leading to qualitative data

Localization

The theory that behaviors have their origin in specific areas of the brain. Damage to that part of the brain would result in an inability to carry out that behavior.

Ethic go- tos

a. Informed Consent: Participants agree to be part of a study after being told what the study is about, what the possible outcomes of the study are, and what their rights are as a participant.

Undue harm/stress: refers to any stress that would be more than a participant would encounter in everyday life. Simple discomfort or embarrassment is not "undue stress or harm."

SM

• localization

Aim: study relationship between amygdala and fear response

• Case Study

Procedures: took her to a variety of places and showed her things that would trigger her fear response

• Haunted house, showed her horror movies, exotic pet store

• Observe her behavior along with asking her to rate her fear level on a 10 point scale

Results: amygdala plays a role in fear responses

Giedd

• Nueroplasticity, nueral networks, pruning

• Longitundinal repeated measures research design

Procedures: conducted MRI scans on children every two years between the ages of 6-20

Results: Found that the brain is constantly changing and adapting

Fisher

• Nuerotransmitters

AIm: determine if there are specific nueral mechanisms associated with romantic love

Sample: men and women who reported being in love for an average of 7.4 months

Procedures

• Participants completed the Passionate Love Scale to measure the traits associated with romantic love

• fMRI machine: shown a picture of their parter for 30 seconds, then shown a distraction for 30 seconds

  • repeated 6 times

Results:

• Brains reward system was active when the participants were looking at a picture of their partner

• Increased levels of dopamine nuerons

Maguire

• Nueroplasticity, localization

Aim: see if London taxi drivers brain would be diffferent as a result of their familarity with the streets of london

Sample: London taxi drivers and non london taxi drivers

Procedures:

• fMRI machine, compared London taxi drivers brain to non london taxi drivers

Results:

• taxi drivers had a significantly larger prosterier hippocampus

• Maguire argues that this explains that the hippocampus may change in response to environmental demands.

Streeter

• inhibitory nuerotransmission

AIM: investigate if changes in mood, anxiety, and GABA (nt) levels are specific to yoga related physical activity

METHOD: true experiment

PROCEDURES: 34 healthy adults- random allocation (19 for yoga, 15 for walking)

• directed to walk or do yoga for 60 minutes three times a week for 12 weeks

• took mood and anxiety scales at 0,4,8,12 weeks and 3 MRS scans

  • scan 1: 0 weeks, baseline scan

  • scan 2: after 12 weeks

  • scan 3: after intervention

RESULTS:

• yoga group reported more improvement and a stronger decrease in anxiety than the walking group

• Positive correlation: increased mood= decreased anxiety= decreased gaba levels

EVAL:

• 12 weeks allowed for consistent comparison; using an MRS machine= increased reliability

• Benefits could be caused by external factors- decreased internal validity

• self reported data- could be biased with social desirability bias

Mishor et al

• pheromones

AIM: studied pheromone Hexadecanal and its link with aggression

PROCEDURES: volunteer sample of men/women, double blind

• sticky pad on lips containing Hex or placebo

• played computer game with mysterious partner- never agreed beforehand (issues with consent)

• Participants could blast opponent with loud noises whenever

RESULTS:

• women exposed to hex= more likely to “punish” opp with noise blast than women with placebo

• men exposed to hex less likely to blast loud noises than those who weren’t

Goetz

• nueroplasticity

AIM:n see if testosterone influence activity in the amygdala

PROCEDURES: 16 healthy young men, lab experiment, repeated measurews

• IV: testosterone or placebo

• DV: fMRI activity while shown images of face expressing different emotions

RESULTS: testosterone condition; reactivity in amygdala/ increased activity in hypothalamus when shown angry faces

EVAL: lab experiment; cause and effect

• controls of testosterone levels

• controls: participant variability

• sampling bias: only had young men, small sample

Draganski (HL)

• nueroplasicity

AIM: see if learning a new skill affects the brain in any way

SAMPLE/METHOD: 24 volunteers between 20 and 24; 21 females 3 females. non jugglers at the start

• pre-test: MRI scan as start of study: base rate for grey matter and brain structure

PROCEDURES: 2 conditions:

1. jugglers: taught three-ball cascade juggling routine; asked to practice routine and notify researchers when they mastered it

2. non jugglers: serves as control group

• juggling group had a second MRI scan, told not to juggle anymore, final scan carried out three months later

• researchers used VBM to determine if there were significant differents in grey matter in jugglers vs non jugglers.

RESULTS:

• jugglers showed significantly larger amount of grey matter in the mid-temporal area of both hemispheres: area associated with visual memory

  • 3 months later: amount of grey matter decreased

• proves nueroplascitiy by showing that the brain can adapt and change when learning new skills

  • synaptic pruning (delete), dendritic branching (add)

Clark and Hatfield

• evolutionary psych

AIM: determine how receptive men vs women are to sexual advanced

METHOD: field experiment- 5 college women/ 4 college men

PROCEDURES:

• stand in area on campus and approach opposite gender- 48 males, 48 females and ask 1/3 questions

  • would you go out with me?

  • would you come to my apartment tonight?

  • would you sleep with me?

RESULTS:

• both sexes responded similarly to request to date

• Apartment/sex males FAR more agreeing (75%) than women (0%)

WHY?

• different roles in child bearing- beneficial for men to have multiple partners because theres a higher probability their genes will be passed on

• women have to be selective- only 1 child per year

  • beneficial to choose mate who will help raise child

Buss (1989)

• evolutionary psych

AIM/PROCEDURES:

• one of the largesr cross-cultural studies ever

• 2 questionaires regarding mate selection

• 10,000+ respondents from 37 cultures

• surveys given participaipants in native language and back translated

RESULTS:

• 36/37 women ranked financial prospects higher than men

• all 37 men preferred younger while women preferred older

• 23 males ranked chastity more important

• agreement in sex differences across cultures implies mate selection preferences are universal

EVAL:

• sampling bias- rural and uneducated underrepresented

• generalizability- cultural validity- diverse

• Construct validity: marriage: some cultures lives together and practiced polygamy

Buss (1991)

AIM: see if men and women experience different forms of jealousy in response to thoughts of infidelity

PROCEDURES: male/female US students asked to think of current/prior partner becoming involved with someone else

• which would be more upsetting?

  • partner forming deep emotional attachment

  • having passionate sex

• pulse measures

RESULTS:

• men more distressed by sexual infidelity- higher heart rate

• women more distressed about emotional infidelity- heart rate normal

EVAL:

• measures heartrate as well as distressing feelings- method triangulation

• low cultural validity- only studied americans

Cases et al

• transgenic mice and MAOA

AIM: studies origins of aggression in transgenic mice

PROCEDURES: removed gene that regulates production of MAOA and introduced mouse to a cage with a control mouse

• transgenic mice: threatening, hunches position, engaged in aggressive behavior

• control mice: “checks out” other mouse by sniffing, non aggressively engaging with mice

• killed the mouse and autopsy its brain

RESULTS:

• autopsies of brain- increased serotonin, dopamine and norepinephrine- MAOA deficient mice were more aggressive

EVAL:

• animal model: aggression manifests differently in humans

• Experimental: cause and effect relationship could not be studied in humans

• Ethical concerns: undue harm and stress, killed the mice afterwords

Albert et al

• castrated mice; testosterone, aggression

AIM: understand the role of testosterone and aggression

PROCEDURES: placed rats in cage and identified the alpha rats (dominant)

• measured testosterone levels when non-aggressive rats were placed in a cage

  • 4 conditions

• 1. castration

• 2. castration and implant tubes with testosterone

• 3. castration and empty tubes (placebo)

• 4. sham castration

  • measured change in aggression when non-aggressive rats put in cage

RESULTS:

• If the operation lowered testosterone levels (A,C)- rats were less aggressive

• if the operation didn’t change testosterone levels (B, D)- no significant change

EVAL: HORRIBLY UNETHICAL

• rat study- determines correlation without ethical concern

• lab study- cause/effect but limited

Rogers and Kesner

• Neurotransmission: Antonova with rats

AIM: Determine role of acetylcholine in formation of spatial memory in rats

PROCEDURES: 30 rats acclimate to Hebbs-Williams maze

• injected half with scopolamine- antagonist for acetylcholine; and half with placebo

CONTROLS: pre-training, random allocation, use of placebo

• assessed by number of errors in start of Day 1 compared to end of Day 1

• late Day 1 compared to early day 2 assessed for retrieval

RESULTS:

• scopolamine group took longer and made more mistakes- highest average of mistakes was in late Day 1

• acetylcholine plays a role in spatial memories

evolutionary theory

• the primary motive for mating is to successfully reproduce

arguments for animal testing

• can lead to creation of safe and effective drugs

• can “ethically “study them for entire life

• more ethical than human testing

• can save lives

arguments against animal use (without ethics)

• Low external validity- cant be 100% sure that results can be generalized to humans

• low construct validity- we have anatomic, metabolic, and cellular differences

• anthropomorphism- seeing a behavior in animals and assuming its the same with humans

animal testing ethics

• utilitarian rights- if experimentation results in greater good use then its acceptable

• Animal rights argument- believes all animals have rights, animal testing is not ethical because

  • undue harm, consent, value of research, right to withdrawl, animal care

the 3 r’s to stopping animal testing

1. replace- use of animals with alternative techniques

2. reduce: use the least amount of animals as possible

3. refine- make sure animals suffer as little as possible

selective breeding

animals that are bred with a goal of producing a specific phenotype

transgenic mice

mice that had a single gene removed to study the role of certain genes