Biological Approach

Question 1

Techniques used to study the brain in relation to behavior: Study one technique used to understand the brain and behavior (The relationship between the brain and behavior).

Answer 1

fMRI (functional magnetic resonance imaging:

Functional due to the fact that it is dynamic, captures brain processes over time.

Usually, a subject is instructed to complete a task, and hence areas of the brain are activated and blood flow increases in said areas. A signal is then obtainable from the oxygenated blood, known as the BOLD signal.

The (spatial) resolution is measured in voxels (volumetric pixels), where one voxel contains several million neurons. The ‘FPS’ of the scan is called temporal resolution, and currently lies at about 1 second.

fMRI is strengthened by good spatial resolution and that it allows to see brain processes.

Limited by poor temporal resolution (no fast brain processes) and the fear (random noise), similar to MRI.

(use Fisher, Aron and Brown (2005) as for section on neurotransmitters).

Question 2

Localization of function: Study one example of localization of function (The relationship between the brain and behavior).

Answer 2

Maguire et al (2000) [see section on neuroplasticity]

Question 3

Neuroplasticity: Study one example of neuroplasticity (The relationship between the brain and behavior).

Answer 3

Maguire et al (2000):
A: correlational study to investigate the structure of the hippocampus to validate a hypothesis that it is involved in spatial abilities.
M: Training program
P: 16 males, right-handed, good health London taxi drivers with 1.5 years’ experience. Control: 50 right-handed healthy males that weren’t taxi drivers. All participants received MRI scans.
R: the volume of gray matter was similar, but it was redistributed for the taxi drivers. They had more gray matter in the posterior hippocampus compared to the anterior as opposed to non-Taxi drivers.
C: Correlation between variables. The hippocampus has been linked to the way in which humans are able to remember directions and where they have been, known as spatial memory.
E: Quasi-experiment: the allocation of groups was not randomized. Only correlational. Not very generalizable. It does however provide evidence in support of the localization of spatial memory in that it could be linked to the hippocampus.

Question 4

Neuroplasticity

Answer 4

the ability of the brain to change through synaptic connections between neurons due to environmental and genetic factors.

Question 5

Neuron

Answer 5

Neurons are nerve cells and the basic building blocks of our entire nervous systems. The neurons act as sensors for all types of stimuli and communicate the stimuli throughout the body – they transfer information throughout the brain, which is communicated through chemical signals.

Question 6

Neural network

Answer 6

series of connected neurons whereby information travels through chemical signals. They help us form habits.

Question 7

Naural/synaptic pruning

Answer 7

When we stop practicing something which we have earlier, our synaptic connections (synapses are how information is travelled, located on our dendrites which are little branches on the neurons) slowly dissipate. We lose synaptic connections because we don’t use them: they are pruned.

Use Draganski et al (2004) for question on neural pruning: juggling, brain scans before during and after; neural pruning occurred. Jugglers and non-jugglers.

Question 8

Neurotransmitters and their effects on behavior: Study one neurotransmitter and its effect on behavior. (The relationship between the brain and behavior).

Answer 8

See Atri et al (2004) in agonists and antagonists.

Question 9

Agonists and antagonists (The relationship between the brain and behavior).

Answer 9

Atri et al (2004):
A: aimed at investigating the role of acetylcholine in memory formation with particular focus centered around what is known as proactive interference, which is when previously acquired information interferes with the acquisition and retrieval of new information. Focused on how the agonist glycepyrrolate and antagonist scopolamine influences the action potential.
M: independent measures design
P: garnered a sample of 28 participants, this sample was required to read a list of 18 related pairs of closely related words (e.g., robber and jail), after which a 30–50-minute delay ensued and they then read another list of words (here, the second word was changed (i.e., robber and x) after this time had elapsed, finally having to recall the words. A second trial followed the same procedure, but participants were admitted either scopolamine, glycopyrrolate, or no injection. As glycopyrrolate is supposed to enhance the acetylcholine receptor sites, it was expected that this agonist would lead to more words being remembered.
R: results showed that, although most conditions lead to a similar mean of words recalled, there was a significant difference between the words recalled for the glycopyrrolate agonist and the participants who were admitted scopolamine.
C: this study therefore proves the role of the agonist glycopyrrolate in its role in enhancing the acetylcholine neurotransmitter and its receptor sites, demonstrating how agonists can operate and effect a given physiological outcome by enhancing the receptor sites of a neurotransmitters.
E: participant differences, since it was not a repeated measures design.

Question 10

Synapse

Answer 10

Located where the axon of one neuron approaches a dendrite or soma (cell body) of another neuron. The connections between neurons. Each neuron, on average, has about 15000 synapses with other neurons. They form synaptic connections, whereby information travels.

Question 11

Excitatory and inhibitory neurotransmitters

Answer 11

Chemical messenger (about 100 of them). They are constantly synthesized in the neutron and moved to the axon terminal to be stored. A released neurotransmitter is available in the synapse for a short period during which it may be metabolized, pulled back through reuptake or reach the post-synaptic membrane (dendrite) and bind to one of the receptors on its surface. Neurotransmitters transmit through the synaptic cleft. Neurotransmitters are either excitatory or inhibitory (excitatory or inhibitory effects on the neuron, meaning they either increase or decrease the likelihood of action potential).

Question 12

Agonist

Answer 12

Chemicals that enhance the action potential of a neurotransmitter

Question 13

Antagonist

Answer 13

Chemicals that counteract a neurotransmitter and so prevent a signal from being passed further.

Question 14

Hormones and their effects on behavior: study one hormone and its effect on behavior (Hormones and pheromones and their effects on behavior)

Answer 14

Hormones: chemical messengers released from endocrine glands that travel through the blood system to influence the nervous system to regulate behaviors such as aggression, mating, and parenting of individuals.

De Dreu et al (2011)
A: Studied whether oxytocin promotes human ethnocentrism, a type of intergroup bias where one’s own ethnic group is perceived as more important than or superior to others.
M: repeated measures design. Used trolley problem.
P: sampled indigenous Dutch male participants. Participants then self-administered oxytocin or a placebo nasally. Afterwards, participants were shown images of people belonging to their in-group (Dutch males) or an outgroup (Middle Easterners/Germans). Finally, used moral choice dilemma tasks such as the trolley dilemma.
R: under oxytocin males were more likely to sacrifice an outgroup target than an ingroup target, while under the placebo there was no difference.
C: This suggests that oxytocin promotes ingroup favoritism.
E: Correlational. Oxytocin has not usually been associated with this behavior.

Question 15

Pheromones and their effects on behavior: Study one pheromone and its effect on behavior. (Hormones and pheromones and their effects on behavior)

Answer 15

Pheromones: Chemical substances responsible for chemical communication – they carry stimulation and affect behavior.

Hare et al (2017):
A: Aimed at investigating whether androstadienone (AND) and estratetraenol (EST) signal gender and affect male perception.
M: Repeated measure design
P: heterosexual participants completed two computer-based tasks twice on two consecutive days. While completing the task, they were exposed to either AND or EST, or just the control scent. The participants were then to look at five gender-neutral facial morphs. In the second task, participants were shown opposite-sex photographs and asked to rate the attractiveness (1-10).
R: Results showed no impact of AND and EST on the rating of attractiveness.
C: AND and EST are not sex pheromones.
E: confounding variables, more smells.

Question 16

Genes and their effects on behavior: study one gene and its link to behavior. (The relationship between genetics and behavior.)

Answer 16

Kaminsky et al (2008)
A: investigated the role of epigenetics in phenotypical differences between MZ twins
M: case study and questionnaires
P: looked at two 49-year-old females, one a war journalist and the other an office manager in a law firm. Personality questionnaires were carried out and showed differences; the law twin had a tendency to overreact to minor problems and is more risk-aversive than war twin.
R: Researchers found one gene, the DLX1 gene (responsible for formation of neurons creating a stress center of the brain) to have an effect.
C: concluded that DLX1 methylation may play a role in the development of stress responses in MZ twins.
E: a bit inconclusive: “may”

Question 17

Genetic similarity: Study genetic similarity (twins, siblings, parents, adopted children) for one behavior. (The relationship between genetics and behavior.)

Answer 17

The transracial adoption study (Minnesota adoption study) (reported by Scarr and Weinberg, 1983):
A: Investigate if black children adopted by white families performed on IQ tests and school achievement as well as other adoptees.
M: Adoption study, longitudinal, correlational.
P: Sampled 101 adoptive families who have biological children and adopted a transracial child. Some of the adopted children were black and others white. The children were adopted around age 0-2. The children were assessed on IQ and school achievement tests.
R: Showed an increase in IQ scores in black children in white families, and that early adoption resulted in higher IQ scores than late adoption.
However, the correlation between the IQ of adoptive parents and adopted children was lower than the correlation between adopted children and their biological parents, which suggests an influence of genetics as well.
C: Adoption increased cognitive abilities – and an increase in IQ occurs due to environmental factors, but the child’s genetics have a say in how the child responds to the environmental factors.
Also, young, adopted siblings had an IQ correlation nearly as high as biological siblings, which contradicts the other findings of genetic factors on cognitive ability (biological parents having correlating IQ to biological child).
E: Ethical considerations?

Question 18

Twin studies

Answer 18

studying dissimilarities between identical twins (monozygotic or MZ) or fraternal (dizygotic) twins.

Question 19

Kinship studies

Answer 19

studies focusing on patterns of social relationships in cultures.

Question 20

Evolutionary explanation for behavior: Study one example of an evolutionary explanation for behavior.

Answer 20

Curtis, Aunger and Rabie (2004):
A: suggested that disgust evolved as protection from the risk of disease.
M: survey/questionnaire
P: Researchers reasoned that if this was true, the following condition would have to be fulfilled:
- disgust should be felt more strongly when faced with a disease-salient stimulus
- disgust should operate in a similar way across cultures
- disgust should be more pronounced in females (have to protect babies)
- disgust should become weaker as the individuals age (don’t have to protect babies anymore)
- disgust should be stronger in contact with strangers.
Researchers made a survey with questions where participants had to (answer where they were from, age, gender, etc.) rate how disgusting certain images were.
R: All five conditions were fulfilled.
C: Study supports the evolutionary explanation of disgust as a response that reduces the risk of disease.
E: Merely a theory.

Question 21

Gene expression

Answer 21

the process by which the heritable information in a gene, the sequence of DNA base pairs, is made into a functional gene product, such as protein or RNA. The basic idea is that DNA is transcribed into RNA [ribonucleic acid] (transcription), which is then translated into proteins (translation). There are many mechanisms that can be used by the body to increase or decrease the production of proteins based on the genetic code. These mechanisms are known as regulation of gene expression, and this results in epigenetic changes (deviation in phenotype from the genetic code in DNA) (https://cdn.britannica.com/96/114896-050-3F22219B/Genes-promoter-regions-production-introns-exons-gene.jpg)

Question 22

Methylation

Answer 22

DNA methylation effects the expression of a gene. It occurs by the addition of a methyl group to the DNA, modifying the function of genes.

Question 23

Epigenetics

Answer 23

the phenomenon of what role genetics take in the shaping of behavior as an organism matures due to biological factors and environmental inputs. This mainly concerns how nurture can have an impact on physiology and behavior. Epigenetic changes are reversible.

Question 24

Animal models (HL extension: animal research)

Answer 24

a concept that refers to using animal research to test a certain cause-effect hypothesis about a certain human behavior. An example would be stress models (explain depression due to exposure to stressful situations), separation models (separation from others causing depression), medical models (chemical imbalances in the brain), etc.

Ethical considerations that can be applied:

• Anesthesia and euthanasia for more humane treatment.
• Guidelines and healthy benevolent treatment for nonhuman animals.
• Non-invasive methodologies and experimental techniques. E.g. behavioral observation

Main experimental manipulation types used in animal models:

• Genetic manipulation (when animals are bred in a certain way)
• Invasive manipulations with the nervous system (brain parts are stimulated with electrodes, lesioned, or removed)
• Invasive manipulations with other body parts (by substances or damage)
• Behavioral and environmental manipulations (e.g. electric shocks for maze training of rats)

Question 25

Advantages and disadvantages of animal research

Answer 25

Advantages:

• Easy gene modification for research
• Animals are easy to control.
• (Potential) medical discoveries
• Increased understanding and development of treatments for neurological and psychological disorders
• Many similarities between mice and humans
• Animals live shorter lives, which allows for studying the full lifespan.
• Inexpensive

Disadvantages and ethical considerations:

• Trivial findings are likely as non-human animals are different than humans in many areas. (E.g. drugs can affect nonhuman animals differently).
• Even if humans and animals are similar in some biological aspects, they can still differ psychologically.
• Animals can’t tell us what they want - they have no saying in their own destiny.
• Environmental (laboratory) and other specific effects will not be taken into consideration when researching phenomena such as depression. - social psychology
• Problems with transferability (to humans).
• An animal model is never going to be 100 percent representative of human anatomy, physiology, cognition or behavior.

Question 26

Ethical guidelines for animal research (APA)

Answer 26

Any animal study should be justified with a clear scientific purpose. It should increase scientific knowledge of behavior, our understanding of a particular species, or have beneficial results for humans or animals.
It should be ensured that the chosen species is the best choice, the minimum number of them is used, and what pain is caused.
Study proposals must be sent to the Ethics Committee.
Researchers must know the normal behavior of the species.
Lab animals must be given humane care.
Studies should always try to minimize discomfort for animals.
If in much pain, the animal should be euthanized.
Lab animals must not be released into the wild.

Question 27

The relationship between the brain and behavior (animal research)

Answer 27

Karl Lashley:
Topic: Brain and behavior (localization).
Study: Lashley’s experiments with rats: removing varying portions of the cortex to see if the memory of the maze disappears
Findings: Performance deterioration depends on the percentage of cortex destroyed but not on the location of the destroyed cells. This challenges the idea of localization of function for memory.
A: localize memory in rats
M: lab experiment
P: removed parts of rats’ brains after having taught them how to run through a maze.
R: Change in behavior was observed after removing certain percentage of the cortex in the hopes of discovering where memory is localized. However, he found that rather than the removal of certain areas of the brain, certain percentage of cortex removed had a correlation to learning abilities.
C: This was later to be known as the principle of mass action. This was further explained by equipotentiality which refers to the ability of one part of the cortex to take over the functions of another part of the cortex.
E: Inconclusive: what parts were being removed? Ethical considerations with the abuse of rats.

Merzenich et al (1984) Topic: Brain and behavior (neuroplasticity) Study: cortical representations of the hand in adult owl monkeys Findings: There was re-specialization of brain matter responsible for one digit so that it became responsible for other, adjacent digits.  A: to study the cortical representation of the hand in eight owl monkeys and map it. M: lab experiment P: 1: Stimulation of areas on all fingers to map the hand digits in the cortex. 2: Middle finger amputated. 3: Another mapping to see the change. R: The area for digit three was removed but reoccupied by digit 2 and 4. C: cortical remapping of sensory inputs from the hand occurs within 62 days in owl monkeys. E: cause-and-effect relationship can be determined, as it is an experimental design and monkeys share genomes, ethical considerations regarding the treatment of animals.

Question 28

Hormones and pheromones and their effects on behavior (animal research)

Answer 28

Romero et al (2014):
Topic: Hormones and behavior
Study: The role of oxytocin in promoting social bonds in mammals in non-reproductive contexts
Findings: Dogs were placed in a room with their owner and another dog. Dogs sprayed with oxytocin showed higher affiliation towards their owner. Similar results were observed for the other dog in the room: affiliation and approach behaviors were more frequent in the oxytocin condition.
A: Oxycontin’s role in promoting social bonds in mammals in non-reproductive contexts.
M: Repeated measures, double blind, counterbalanced design
P: 16 dogs sprayed intra-nasally with oxytocin or placebo. Dog placed with their owner and another dog in the same, empty, room. Owner moved every 10 minutes and behavior recorded.
R: results showed that dogs sprayed with oxytocin showed higher affiliation towards their owner.
C: researchers concluded that oxytocin performs the function of maintaining close social bonds in mammals.
E: limited generalizability.

Young and Olzábal (2006): A: investigate the correlation between oxytocin (the love hormone) receptor density in the nucleus accumbens and “spontaneous mothering” in prairie voles to understand oxytocin’s role in affection and motherly behavior.  M: lab experiment (?) P: 40 sexually naïve female prairie voles in an enclosure with newborns. 24 of them displayed spontaneous mothering. Researchers then observed oxytocin levels in the nucleus accumbens.  R: Results showed a statistically significant increase in oxytocin levels. C: naturally occurring higher levels of oxytocin receptor density led to the spontaneous mothering.  E: Only have of sample displayed this. Generalizable to humans?

Question 29

The relationship between genetics and behavior (animal research)

Answer 29

Weaver et al (2004):
Topic: Genetics and behavior (epigenetics)
Study: Weaver et al (2004): epigenetic research on how the type of nurturing rats receive from their mothers in early life affects the way their brain responds to stress in later life.
A: investigate the effects of environment on behavior, here levels of stress.
M: combination: quasi experiment, rat adoption study, an independent measures design experiment.
P: Compared rats who had experienced low or high levels of affection. Then, the stress levels of the rats were measured by placing each rat in a confined tube for 20 minutes and then recording the amount of corticosterone, a stress hormone, was in the rat after the confined tube. Another experiment: two conditions where rats where either nurtured a lot by mothers or very little.
R: Less nurturing in early life was linked to the suppression of the glucocorticoid receptor gene. The genetic sequences themselves did not differ.
C: This study demonstrates the effects of gene suppression on behavior, and how genes and gene expression may be affected by the environment. Vulnerability to stress may therefore be determined by epigenetic factors: methylation of a gene responsible for production of stress hormone receptors.
E: ethical considerations and limited generalizability.

Francis et al (1999):  A: Investigate how the interaction between genes and the environment influence how rats nurture their offspring and whether this is heritable. M: independent measures design P: Within the first 12 hours of being born, baby rats were switched to either mother’s that show affection a lot versus some that don’t. There were also two control groups in which the pup remained with their biological mothers. Results: The rats raised by affectionate mothers grew up to be less stressed and eventually became more affectionate themselves (even if they were with not so affectionate mothers). Through an examination of the rat's genetics, the researchers found that the rats raised by affectionate mothers had lost the methyl groups around the associated genes, allowing them to be expressed. C: this study supports that being raised in a nurturing, affectionate environment causes changes in gene expression, which is then passed onto the next generation.  E: Ethical considerations with swapping babies. Generalizable to humans?

Question 30

fMRI scanner study

Answer 30

Fisher, Aron and Brown (2005):
A: investigating the neural mechanisms of romantic love
M: Self-selected sampling. fMRI of ten men and seven women who were ‘intensely in love’
P: Participants were shown photos of their love and later an emotionally neutral acquaintance with countdowns in between.
R: Pattern of activation in the ventral tegmental area and caudate nucleus (both rich in dopamine) in response to photos of loved ones. These dopamine-rich regions form the dopaminergic pathway, which increases dopamine activity in the brain.
C: Dopamine activity in the brain plays a role in romantic love, as dopaminergic activity is linked to motivation and pleasure.
E: What constitutes being ‘intensely in love?’
How acquainted where the ‘emotionally neutral acquaintances’?
Fatigue due to the procedure being repeated 6 times.