Biological Approach Flashcards
Studies for Biological Approach (17 Total)
Localization (2)
Neuroplasticity (3)
Neurotransmitters and behavior (2)
Influence of hormones on behavior (3)
Influence of pheromones on behavior (2)
Genes and Behavior (3)
Evolutionary explanations to behavior (2)
Localization:
-Experiment, Karl Lashley 1929
-Split brain case study, Sperry 1968 and Gazzaniga 1967
Neuroplasticity:
-Experiment, Merzenich et al 1984
-Experiment, Draganski et al 2004
-Quasi-experiment, Maguire et al 2000
Neurotransmitters and behavior:
-Experiment, Crockett et al 2010
-Experiment, Freed et al 2001
Influence of hormones on behavior
-Experiment, Ferguson et al 2000
-Experiment, Scheele et al 2012
-Experiment De drue et al 2011
Influence of pheromones on behavior
-Experiment, Lundstrom and Olsson 2005
-Experiment, Cutler, Friedman and McCoy 1998
Genes and Behavior
-Meta-analysis, Bouchard and McGue 1981
-Adoption study, Scarr and Weinberg 1983
-Longitudinal study, Caspi et al 2003
Evolutionary explanations to behavior
-Correlational study, Curtis, Aunger and Rabie 2004
- Fessler et al 2005
Localization of function
The theory that certain areas of the brain are responsible for certain functions
Strict localization def mock
The idea that functions can be mapped to certain parts of the brain
Weak localization
The idea that a function is not exclusive to one part of the brain and may be taken over by other parts
Widely distributed functions def
Functions that are not localized to anywhere in the brain
Aphasia
Brocas aphasia, inability to speak and write while maintaining comprehension. Posterior inferior frontal gyrus.
Wernickes aphasia, impaired speech comprehension but their speech is intact. Temporal lobe of the dominant hemisphere.
Karl Lashley 1929
Procedure: Trained rats to go through maze and find food, then removed 10%-50% of the cortex.
Results: The memory of the maze was a factor the percentage removed rather than which area.
Conclusion: Memory is not localized, it is distributed across the cortex, and different functions can be overtaken by different parts of the brain.
Sperry and Gazzaniga 1967-1968
Method: In depth case study
Aim: Investigating how two hemispheres function independently
Participants: four patients with severed corpus collosum to treat epilepsy
Procedure: Items were flashed on a screen to their left or right eye or feeling objects behind curtain with one hand.
Results:
When the left eye saw an object they could not describe it, but the left hand could feel around and find that object, but participants could not explain why.
Language is localized to the left hemisphere.
But when words were flashed a similar effect would occur, therefore the right hemisphere has some language comprehension
Language comprehension is a function of both (weak localization)
Conclusion: Language localization is not strict
Language production and comprehension are mostly localized to the left hemisphere, but the right can perform simple tasks.
MUST MENTION THIS STUDY IS ON LATERALIZATION ( a type of localization)
Cortical remapping def
Neuroplasticity on the level of the cortex
Neuroplasticity def
The ability of the brain to change itself in response to environmental demands
Merzenich et al 1984
Method: Experiment, repeated measure design
Aim: How the sensory cortex which controls the hand will respond to injury
Participants: Eight adult owl monkeys
Procedure: Electrodes were attached to skull, so that the are of the cortex responsible for hand control was being read by the electrodes. Then different fingers were stimulated, and it was recorded which electrodes responded to the stimuli.
One or several fingers were amputated, and 62 days after the amputation the adaptation of the cortex was observed
Results: First mapping showed 5 adjacent areas, each responsible for one finger. Second mapping, post amputation shows adjacent area took over non-used areas.
Conclusion: The sensory cortex of owl monkeys adapts to injury by cortical remapping,
Draganski et al 2004
Method: Experiment, mixed design
Aim: Investigate whether structural changes would occur in the brain due a juggling routine.
Participants: Self selected sampling of 24 people with no experience in juggling
Procedure: Two groups, jugglers and non-jugglers.
Jugglers spent 3 months learning how to juggle, followed by 3 months of no practice. The second group was a control and never learned juggling.
MRI scans after 3 months and 6 months on both groups
Results: No difference in brain structure before experiment
After 3 months jugglers had significantly more grey matter in areas responsible for coordination of movement (mid-temporal)
After 6 months the difference decreased, however, they still had more grey matter than in the first scan
Conclusion: Grey matter grows in the brain in response to stimuli and shrinks in absence of stimuli. Therefore there is a cause and effect relationship between learning and brain structure.
Maguire et al 2000
Method: Quasi-experiment
Aim: How brain structure of London taxi drivers compare to others
Participants: 16 right hand male taxi drivers, with avg experience of 14 years
50 healthy right-handed men who didn’t drive a taxi as a control
Procedure: MRI scans of both groups were compared
Results: Taxi drivers had more grey matter in posterior hippocampus, and control group had more grey matter in anterior hippocampus.
A correlation was seen between grey matter volume and experience of taxi driving.
Conclusion: Grey matter from the anterior hippocampus was redistributed to the posterior hippocampus.
The posterior hippocampus is know to be involved in using previously learned spatial memory, while anterior hippocampus is know to be used in learning new spatial memory
Agonist def
A chemical that enhances the action of a neurotransmitter
Antagonist def
A chemical that inhibits the action of a neurotransmitter
Neurotransmitter def
A chemical messenger stored in the axon and released into the synaptic gap
SSRIs
A class of chemicals that prevent the reuptake of excess serotonin in the synapse
Crockett et al 2010
Method: Experiment, counterbalanced , repeated measure design and double blind
Aim: Investigate the effect of serotonin on prosocial behavior
Participants: 30 healthy volunteers
Procedure: In condition one participants given an SSRI, and condition 2 were given a placebo
Presented with two moral dilemmas, personal and impersonal in which it involves deciding whether 1 or 5 people die.
Results: Impersonal scenario participants were unaffected, personal scenario participants were less likely to interfere.
Conclusion: SSRI reduced the acceptability of personal harm and thus promotes prosocial behavior. Increased serotonin in the brain may cause people to be reluctant to inflict harm
Freed et al 2001
Method: Experiment, independent measure design
Aim: Investigate effect of dopamine on Parkinson’s disease.
Participants: 40, 34-75 year olds with severe Parkinson’s disease,
Procedure: Dopamine producing nerve cells were transplanted into the participants brain.
Control group underwent surgery without receiving the dopamine producing nerve cells
PET scans, interviews and observations were conducted over the span of a year
Results: Participants under 60 had a 28% decrease in symptoms after receiving dopamine producing tissue
Conclusion: Transplanting dopamine producing tissue into the brain reduces symptoms of sever Parkinson’s disease in younger but not older patients, therefore dopamine has an effect on behavior
Fisher, Aron and Brown 2005 (Not Mock)
Method: Experiment, repeated measure design
Aim: Investigate neural mechanisms of romantic love
Participants: 17 participants “intensely in love” for a mean duration of 7 months
Procedure: Participants were placed in an fMRI scanner and went through 4 steps which were repeated 6 times.
-Viewing photo of person they love for 30 seconds
-Filler activity for 40 seconds
-Neutral acquaintance photo for 30 seconds
-Filler activity 20 seconds
Results: Specific pattern activation of dopamine rich areas of the brain in response to phot of loved one
Conclusion: Activity of dopamine plays a role in the romantic feeling
Ferguson et al 2000
Method: Experiment, mixed design
Aim: Investigate the role of oxytocin in social memory in rodents.
Participants: 42 oxytocin gene knockout mice and 42 mice with normal genotype. All mice were male.
Procedure: Female mouse was introduced into the cage for one minute. This was done 4 times with the same mouse. On the fifth trial a new female mouse was introduced.
Behavior was scored and recorded by trained raters. Time spent sniffing the female mouse was the operationalization
Results: Mice with normal genotype spent less and less time sniffing the female mouse with each trial. On the fifth trial the time spent sniffing was the same as the original time
Oxytocin knockout mice spent the same amount of time sniffing on all trials
Conclusion: Oxytocin is necessary for developing social memory in mice and plays a role in recognizing members of the same species.
Scheele et al 2012
Method: Experiment, independent measure design, double blind
Aim: Investigate the role of oxytocin promoting fidelity
Participants: 86 heterosexual men, some single and some in a stable relationship
Procedure: Either oxytocin or a placebo was given to participants nasally
1. Stop distance paradigm- Participants stood at one end of the room across an attractive female and the men slowly approached them until they got to an uncomfortable distance
2.Approach/Avoidance task- Participants were positioned in front of a screen with a joy stick and show a series of 4 picture types:
-Positive social pictures (attractive women)
-Positive non social pictures (beautiful landscape)
-Negative social pictures (mutilations)
-Negative non social pictures (dirt)
Using the joy stick the participants indicated their enjoyment by enlarging the image
Results: Oxytocin participants kept a larger distance only when in a stable relationship.
Only positive social pictures were affected by oxytocin with men in a relationships enlarging the image more slowly and with a larger delay than single men
Conclusion: Oxytocin causes men in a relationship to keep a greater distance to attractive females who are not their partner, thus it promotes fidelity
Oxytocin is highly specific to the stimuli of attractive women
Lundstrom and Olsson 2005
Method: 2 x 2 Repeated measures design - Experiment
Aim: Investigate the effect of androstadienone (AND) the mood of women in the presence of men
Participants: 37 heterosexual women, with a normal menstrual cycle
Procedure: The women were assessed after being exposed to either androstedienone (AND) or a control solution and in the presence or absence of a male.
Questionnaires were conducted on the females by a female or male experimenter
Results: Androstadienone increased women’s mood in the presence of a male experimenter but not a female experimenter.
Conclusion: Androstadienone may serve the function of signaling sexual attractiveness
Hare et al 2017 (Not Mock)
Method: Experiment, repeated measure design
Aim: Investigate if Androstadienone (AND) and estratetraenol (EST) signal gender and affect mate perception
Participants: 140 heterosexual adults
Procedure: Participants completed two computer based tasks for two consecutive. On one of those days they were exposed to AND or EST masked with clove oil. On the other day they were exposed to the control scent. This was counter balanced.
In the first task participants were shown five gender neutral facial morphs and had to indicate the gender.
In the second task they were show photographs of individuals of the opposite sex and asked to rate their attractiveness.
Results: There was no difference in conditions for the first task nor a difference in rating attractiveness in task 2
Conclusion: AND and EST do not act as signals of gender or attractiveness. These chemicals do not qualify as human pheromones.
Cutler, Freidman and McCoy 1998
Method: Field experiment, independent measure design
Aim: To investigate if a synthesized human pheromone can increase sociosexual behavior of men
Participants: 38 men aged 25-42, heterosexual volunteers in good health and a regular appearance
Procedure: Each participant used their regular aftershave and filled out a behavioral calendar daily on six behaviors:
-kissing
-sleeping next to a partner
-sexual intercourse
-informal and formal dates
-masturbation
There was a baseline for two weeks. After the baseline either ethanol or a synthesized pheromone with ethanol into their aftershave.
This was followed by 6 more weeks of using the after shave and filling out the calendar
Results: Participants in the pheromone group showed an increase over the baseline in the first four behaviors and no differences between groups in formal dates and masturbation
Conclusion: Synthetic pheromone increased attractiveness of women to men or the pheromone caused the men’s libido to increase but no increase in masturbation contradicts this theory.
DNA Methylation def
The process by which certain chemicals are added to the DNA molecule, affecting gene transcription
Epigenetic changes def
Deviations of the phenotype from genotype occurring due to changes in gene expression
Gene def
A part of DNA responsible for a specific trait or behavior
Gene expression def
The process of synthesizing organic molecules based on the DNA blueprint; manifesting the genotype in phenotypical traits
Gene transcription def
The replication of a DNA sequence to an RNA molecules
Gene translation def
Decoding RNA into a sequence of amino acids to from a protein
Genotype def
A set of traits encoded in an individuals DNA
Phenotype def
A set of observable characteristics
Bouchard and McGue 1981
Method: Meta analysis
Aim: To estimate heritability of IQ
Participants: 111 twin studies which consisted of MZ and DZ twins, siblings, each either reared together or apart, as well as parents and their offspring
Procedure: Calculated median correlations of IQ Scores
Results: MZ twins reared together 0.85 correlation
MZ twins reared apart 0.67 correlation
DZ twins reared together 0.58 correlation
Siblings reared together 0.45 correlation
Conclusion: 54% of intelligence is inherited considering falconers models
However, the fact MZ twins reared together didn’t have a correlation of 1.00 shows that the environment plays a role in the development of IQ
Scarr and Weinberg 1983
Method: Adaption study
Aim: Investigate environmental malleability of intelligence
Participants: 101 adoptive families who hap both biological and adopted children. Some adopted children were white, other black. Some were adopted before 12 months of age others after. At the time of the study in Minnesota, being black usually meant having a lower socio-economical status.
Procedure: Children were assessed on IQ and school achievement tests. Correlations were calculated between IQ of children and parents
Results: Group - Avg IQ
Black children in their own homes - 90
Adopted black children - 106
Black children adopted in first 12 months - 110
Adopted white children - 111
Biological children of adoptive parents - 119
Adoptive parents - 120
Correlation
Adoptive parents and adopted children 0.29
Adopted children and their biological parents 0.43
Conclusion: Improvement of IQ of adopted children and higher correlation between biological parents suggests additive influence
Caspi et al 2003
Method: Longitudinal study, genetic mapping divided participants into 3 groups:
-two short alleles of 5-HTT
-one short allele of 5-HTT
-two long alleles of 5-HTT
Aim: Investigate the role of 5-HTT gene in developing depression in response to stressful life events
Participants: 1,037 children from New Zealand
Procedure: Participants were assessed between ages 3-26, by a life history calendar to assess stress and interviews to assess depression
Results: one or two short allele participants developed more depressive symptoms to stress
Conclusion: 5-HTT gene is responsible for modulating an individuals vulnerability to stress.
What happens to neurotransmitters in the synapse
-They can diffuse across the junction and bind to the receptors of the next neuron
-Reuptake of neurotransmitters into releasing neuron
Limitations of Neurotransmitter research (4)
-It may be undirect
-The effect might be postponed
-X may not be the only factor affecting Z
- X may results in various side effects
5 techniques
-CT
-MRI
-fMRI
-PET
-EEG
Spatial resolution def
The ability of a scanner to discriminate between nearby locations
Temporal resolution def
The smallest time period in which a brain scan can register changes in the brain
CAT scan
X-rays in a large cylindrical apparatus
Pro: Quick and non-invasive, allowed for those with metal implants
Con: Radiation exposure
MRI
Nuclei emit energy to response of a magnetic field in large cylindrical apparatus
Pro: No radiation and a better spatial resolution
Con: High resolution may pic up abnormalities causing panic, people with metal transplants are not eligible, MRIs are expensive and may not be suitable with claustrophobia
fMRI
Blood-oxygen-level dependent signals in the brain. Oxidized blood emits energy in a magnetic field.
Similar to MRIs but participants can carry out tasks.
Pros: Great spatial memory, can map brain structure and shows ongoing processes
Cons: Random thoughts and movements may cause anomalies
PET scans
Radioactive tracer in blood stream emits energy, The more active areas of the brain require more blood therefore more energy will be emitted from that area
Pro: Good spatial resolution, small and portable scanner
Cons: Radioactivity exposure, and poor temporal resolution.
EEG
Electrical pulses sensed by electrodes attached to the scalp
Pros: Perfect temporal resolution, non-invasive
Cons: Poor spatial resolution, can’t detect subcortical areas
Oxytocin def
A hormone produced by the hypothalamus and released by the pituitary gland; known for its role in social interactions and sexual reproduction (not a sex hormone!)
Gene knockout def
A technique in which genes of an organism are turned off
Pheromone def
A chemical messenger that communicates information from one member of a species to another.
Pheromone processing in mammals
The VNO located in the nasal cavity is connected via nerves to the accessory olfactory bulb. Humans also have this but lose it after birth, those who keep it have it inactive.
Criticism on human pheromone research (3)
-Inconclusive research
-Contradictory findings
-Commercial interest
Nature vs Nurture debate
The debate whether biological factors (inheritance) or environmental factors influence behavior.
Falconer model
A way to estimate heritability of a trait from observed similarities between MZ and DZ twins
Niche-picking def
The phenomenon in which genetic predisposition causes individuals to select certain environments which in return influences behavior
Theory of evolution
Those which are best adapted to the environment are the best fit to survive, when an environmental pressure occurs, the best fit survive and reproduce passing on their superior genotype.
What are the 4 major parts of the brain?
-Cortex
-Cerebellum
-Limbic system
-Brain stem
Parts of the cortex
-Frontal lobe
-Parietal lobe
-Occipital lobe
-Temporal lobe
Parts of the Limbic system
-Thalamus
-Hypothalamus
-Amygdala
-Hippocampus
What is the Cortical Homunculus?
A map of the sensory cortex to which part of the body it controls
What is the principle of mass action?
Brain performance deterioration depends of the percentage of cortex destroyed
What is Equipotentiality?
The ability for one part of the brain to take over for another
What is synaptic plasticity?
The formation of new links between neurons
What is sense substitution?
The idea that other sense can take over for lost senses
Excitatory neurotransmitters and Inhibitory neurotransmitters
Excitatory produce a stimulating effect, inhibitory stop signals from passing and calm the brain
Criticism of evolutionary explanations in psychology (4)
-Speculation about the environment
-Testability (Ad hoc reasoning)
-Assuming the linearity of development
-Cultural variation
Curtis, Aunger and Rabie 2004
Aim: To test if disgust is a product if evolution by seeing if the following are true:
-Disgust should be stronger in response to stimuli that are associated with disease
-Disgust response should be similar cross-culturally
-Disgust should be more prevalent in females
-Disgust should become weaker with age
Participants: 77,000 volunteers form 165 countries
Method: Correlational study
Procedure: Via a Survey on the BBC website, participants filled out questions about their age and origin.
Then, 20 pairs of photographs were presented, with each pair having one disease related picture. Participants on a sale from 1-5 would rate how disgusting a photo was.
Results: All the four statements were proven
Define hormone
Hormones are a particular class of chemical that affect human behaviour. Hormones are produced in the human body by glands that make up the endocrine system. Hormones are then released into the blood stream, where they can influence behaviour
How does oxytocin promote monogamy?
Researchers believe that oxytocin’s influence on reward pathways creates a positive behaviour loop for engaging in social and sexual contact with a reliable, monogamous partner.
During sex oxytocin is released, causing dopamine to release in the reward pathway which in turn provides pleasure. This is the reward pathway creating a positive behaviour loop.
De Drue et al 2011
Aim: Test the role of oxytocin on Ethnocentrism
Participants: Indigenouss Dutch men
Method: Double blind independent measures experiment
Procedure: Oxytocin or placebo nasally self administered. The men were faced with moral dilemas where either one memeber of their inner group was to be killed or in other conditions a member of their outer group and Alternativley 5 men with unkown ethniciity. The names were manipulated to set if the member was in the ingroup or outgroup within the trial.
Results: Placebo showed no signiificant difference. Experiemntal showed that oxytocin condition was more likey to not sacrifice ingroup member but also not more likely to sacrafice outgroup member. Therefore oxytocin promotess ingroup favoratism
Fessler et al 2005
Aim: To investigate if disgust sensitivity in the first trimester of pregnancy was elevated
Method: Survey
Procedure: - A Web-based survey was completed by 691 women recruited through pregnancy-related Web sites.
- No compensation was offered for participation. The women’s mean age was 28.1 years.
- On the Web-based questionnaire, the participants (1) indicated their current level of nausea using a 16-point scale and (2) answered questions to test their disgust sensitivity in eight different areas (e.g. food; contact with animals, body products, and dead animals; hygiene; contact with toilets)
Results: - Overall, disgust sensitivity related to food and body products in women in the first trimester was higher compared to those in the second and third trimesters.
- Disgust was particularly elevated in relation to food.
Concusion:
- Food-borne diseases are particularly dangerous to women in the first trimester and therefore it was predicted that disgust sensitivity related to food would be high. This was supported by the results.
- The results may indicate that nausea and vomiting are evolved behavior because they limit the likelihood that pregnant women will eat dangerous food.
