Biological Approach Quiz for seniors

Describe excitatory and inhibitory neurotransmitters and give an example of each.

Excitatory neurotransmitters increase the chance that the recieving neuron will generate an action potential while inhibitory neurotransmitters decrease the likelihood that the recieving neuron will generate an action potential. An example of an inhibitory neurotransmitter is serotonin. Glutamate is an excitatory neurotransmitter.

Describe agonists and antagonists and give an example of each.

Agonists and antagonists are chemicals which affect the function of neurotransmitters. Agonists increase the effect of neurotransmitters while antagonists decrease the effect of neurotransmitters. SSRIs are serotonin agonists and ketamine is a glutamate antagonist.

Describe two ways agonists function and one way antagonists function.

Agonists function by mimicking the neurotransmitter and binding to the receptors themselves or by reducing degradation or reuptake of the neurotransmitter..For example, . Antagonists work by binding to and blocking receptor sites on the neurons.

Describe two ways serotonin influences human behavior.

Serotonin influences human behavior by playing a role in sleep and may increase pro-social behavior. It can also affect mood and low amount of serotonin might be accociated with risk of developing depression.

Describe two ways glutamate influences human behavior.

Glutamate is associated with memory and learning. Glutamate also promotes wakefulness, are accociated with increased pain response, and may also contribute to symptoms of depression.

Describe an action potential.

an electrical signal that travels from cell body to axon terminals; it involves a quick voltage change across the cell membrane

Describe synaptic transmission.

process of neurotransmitter released from presynaptic neuron into synapse, bind to receptors on postsynaptic neuron creating a response

Describe how neurotransmitters are removed from the synapse.

reuptake by presynaptic neurons or degradation by enzymes in synaptic gap

Define neuroplasticity and name the three processes that occur during neuroplasticity.

Neuroplasticity is the ability of the brain to change itself. The three proceses are synaptogenesis (creation of new synapses), neural pruning (the destruction of old synapses), and long-term potentiation (the strengthening of existing synapses)

Describe 2 examples of evidence for neuroplasticity.

1) The growth and shrinkage in grey matter of the brain indicates synaptogenisis and neural pruning as one either gains or loses a skill (Ex: Draganski's jugglers had increased the grey matter in their motor region). 2) Other parts of the brain take over the lost function of damaged areas (Ex: Over time patients have successfully regained control over previous paralized body parts)

Describe one imaging technique, including how it works, spatial and temporal resolution, and how it can be used in psychology.

fMRI measures brain activiation by tracking oxgenated blood flow in the brain. In an fMRI, the protons in the body align with the magnetic field; when the magnetic field is turned off, the protons return to their original positions and release pulses of energy. Spatial resolution: 1cubic mm; Temporal resolution: 1 second

Describe localization of function and give an example of a localized function.

Localization is the theory that specific tasks are set to be done by specific parts of the brain . An example is that expressive language is localized in Broca's area.

Describe 3 types of evidence for localization.

Localization can be demonstrated from loss-of-function studies (matching an area of brain damage to the loss of skill), from using an fMRI or PET scan (showing which areas of the brain are active when someone does a specific task), or from doing repeat MRI scans and looking for growth of a specific area of the brain following practice of a specific skill

Describe hormones.

Hormones are chemical messengers produced by glands and released into the blood stream to affect cells throughout the body. Hormones are slower and longer-lasting than neurotransmitters.

Describe one hormone including what gland releases it and its physiological and psychological effects.

Oxcytocin is a hormone that is released by the pituitary gland. The physiological effects of oxcytocin include increasing labor contractions and milk letdown during breastfeeding. The psychological effects include promoting social bonds between parents and babies, and romantic partners.

Describe pheromones and behaviors commonly associated with pheromones.

Pheromones are chemicals released into the environment by an organism, affecting the behavior or physiology of other members of the same species. Behaviors commonly associated with pheromones are mating, raising an alarm, or signaling food.

Define evolution, natural selection, & sexual selection.

Evolution is the change in heritable characteristics of a population over time. There are many mechanisms of evolution including mutation, drift, and migration, but only selection produces adaptation. Natural Selection occurs if a heritable trait leads to increased survival and reproduction. Over time, this trait is expected to increase in the population. Sexual Selection is a type of natural selection related to mate choice.

Since females are usually a limiting resource when it comes to reproduction, sexual selection in most species favors ...

Choosy females who pick mates who can give them the most or best quality offspring (picking based on factors such as resources, protection, good genes, or good parenting) and showy (decorative) or competitive males who compete for females or they resources they want

Define neural networks.

Neural networks are the "communication pathways" in the brain - groups of neurons, connected by synapses that communicate with each other.

Describe SSRIs and how they work.

SSRI's are agonists of serotonin and increase the levels of serotonin by blocking reuptake, essentially making more serotonin available to transmit signals between nerve cells

Define gene, alleles, and genetic relatedness.

Genes are regions of DNA that encode for a protein. Alleles are different versions of the same gene. Genetic relatedness is the proportion of alleles two individuals are expected to share due to their family relationship, and it ranges from 0-1.

Describe a study related to localization.

Study: Lashley 1950 | Aim: Determine where memory of maze is stored in cortex. | Sample: Healthy Rats | Method: Experiment | Description: Mice were trained to run a maze, and after learning it, Lashley surgically removed varying amounts (10% to 50%) of their cerebral cortex from different locations. He then placed them back into the maze and observed their behavior. The Independent Variable was the amount and location of cerebral cortex removed and the Dependent Variable was the mice's performance in the maze. | Results: Maze performance was not affected by the location of the brain lesion, as all mice retained some ability to complete the maze. However, performance worsened as the amount of cortex removed increased. | Conclusion: Lashley's findings suggest that memory is widely distributed across the cerebral cortex, with task performance depending on the percentage of cells damaged, not location (principle of mass action) and undamaged areas compensating for damaged ones (equipotentiality).

Describe a study related to neuroplasticity.

A study related to neuroplasticity is Draganski et al. 2004. The aim of the study was to determine if the brain changes in response to specific activities (juggling). The sample was taken using self-selected sampling and consisted of 24 individuals in their early 20s who didn't have any pre-exsting experience with juggling. The subjects were then randomly assigned to a treatment group: jugglers or non-jugglers. The jugglers would be the ones larning and practicing a basic 3-ball juggling technique while the non-jugglers served as a control group. To determine the change in the brain from the beginning to the end, MRIs were conducted at the start of the experiment, after 3 months of practice, and then after another 3 months when the jugglers stopped practicing. The method was an experiment. The independent variable was the group the participants were asisnged into and the dependent variable was the change in brain matter in the mid-temporal area. After conducting the experiment, the researchers found out that there were no significant differences in the brains of the jugglers and non-jugglers at the start of the experiment. However, there was a significant increase in gray matter volume in the mid-temporal area in the jugglers after 3 months of practice. Lastly, after 3 months of practicing, the volume of grey matter decreased signifiacntly. These results reinforce the idea that constant practice results in synaptogenesis and long term potentiation while a lack of practice results in neural pruning.

Describe a study related to neurotransmitters.

A study related to neurotransmitters is Crockett et al 2010. The aim was to determine if serotonin had an effect on pro-social behavior, using citalopram as the SSRI. The sample was 24 people, both male and female, mean age of 26. All were healthy and had no history of abuse. It was an experiment, counterbalanced, repeated measures, and a double blind design. The participants were asked to respond to 6 non moral dilemmas, 6 impersonal dilemmas, and 16 personal dilemmas. Non-moral dilemmas involved a choice unrelated to morality. Impersonal and Personal moral dilemmas both involved a choice to harm one person in order to save several others, but personal moral dilemmas involved a more direct harmful action (such as pushing someone into danger). The results were that there was no significant difference between citalopram and the placebo in response to impersonal and non moral dilemmas, however the SSRI significantly reduced the "acceptability" of going through with a harmful action in the personal version of the dilemma. The conclusion is that serotonin may play a role in promoting pro-social behavior by making it seem less acceptable to hurt others. (Note: you might want to use TADS instead of this to reduce total number of studies you need to know.)

Describe a study related to hormones.

Kosfeld et al aimed at determining whether oxytocin influences levels of trust among strangers in an investment game. The sample was male university students from universities in Zurich (excluded if they had a physical/psychological illness, medication usage, drug/alcohol abuse, or if they didn't believe they were playing against a real person after the game). The method was an experiment (random allocation to recieve placebo or oxytocin). Participants in the trust experiment played 4 rounds of the investment game against 4 different strangers while those in the risk experiment played 4 rounds against a computer whose responses were modeled after those of real people. In the game, participants could invest in trustees (human or computer), and their investments would automatically be tripled. Trustees could then choose how much (if any) money to give back to the investors The IV was whether participants were administered oxytocin before the game and the DV was the amount of money participants invested with their partner (indicating level of trust). The results showed that oxytocin significantly increased investments when the game was played against people, but there was no effect when the game was played against the computer. The study concluded that oxytocin increases trust in interpersonal relationships (indicated by the lack of effect with a computer - which also helps to rule out alternate explanations like effect on mood or risk avoidance)

Describe a study related to pheromones.

Mishor et al. (2021) aimed to investigate the role of hexadecanal, a putative pheromone found on the heads of infants, on aggression. The sample included healthy young adults. The method was double-blind, independent measures experiment. Each participant atached a sticky pad to their upper lip and half of the sticky pads were soaked in hexadecanal and the other half in a placebo (IV). Each participant told that they would play a game on computer against another participant. In reality, each participant was playing against a computer that whose responses were programmed. In the first game, participants were repeatedly offered small sums of money and told they could keep itif they and their partner could agree how to divide it. The problem was the other participant (computer) would only agree to divide the money if they got the greater share. This task was designed to cause feelings of aggression. The second game appeared to be a reaction time test, but in reality the participant was guaranteed to win a certain percentage of times. Each time the participant won, they chould 'punish' their opponent by blasting them with sound. The purpose of this game was to measure aggression by the volume of the sound used to punish the opponent (DV). The results showed that hexadecanal reduced aggression in men but increased aggresion in women. This suggests that hexadecanal might be a pheromone because it is produced humans, released into the environment, and effects the behavior of other.

Describe a study related to genes.

Capsi et al: The aim is to determine if different alleles for a serotonin transport gene are associated with depression in response to stressful life events. This is an quasi-experiment and the sample consists of 25 year olds from a longitudinal study. The independent variables were genotype and number of stressful life events within the past 5 years. The dependent variable is whether or not the participant had MDD (all participants underwent a diagnostic interview with a trained clinical psychologist). The results showed that having several stressful life strongly predicted risk of depression. Genotype by itself was not correlated with risk of depression, however, among people with 3 or more stressful life events, people who had the short allele for the serotonin transport gene were at increased risk of depression. The results show that the genes influence risk of depression, under certain environmental conditions.

Describe a study related to genetic similarity.

Bouchard et al. 1990 - Minnesota Twin Study Aim: determine the extent to which genes influence IQ. The sample was derived from self-selection of more than 137 monozygotic (MZ) and dizygotic (DZ) twins from around the world, who were either reared together or separately with an average age of 41.Method: Twin study / quasi-experiment. Participants took IQ tests(primary focus), were interviewed, and were tested in other aspects Description: Monozygotic and dizygotic twins, both reared apart and together, wereanalyzed through various methods of testing, including IQ tests, personality inventories, and life history interviews. The Independent Variable was were the twins were reared together or apart and if they were Monozygotic or dizygotic twins. Dependent Variables was similarity (between-twin correlation) of IQ scores, personality traits, and social attitudes. Results: IQ scores of MZ twins reared together had the highest similarity in IQ (r = .88) followed by MZ eared apart (0.69). DZ twins reared together and DZ reared apart had much less similarity. The high similarity of MZ twins (regardless of how they were reared indicate a strong role for genetics in IQ. The greater similarity of reared together compared to reared apart within each type of twin indicates environment also plays a role, though smaller. Researchers esimated that70% of variation in IQ is due to genetic factors, and about 30% is due to environmental factors.

Describe a study related to evolution.

"Wedekind et al 1995: This Quasi-Experiment, related to evolution, aimed to determine wether women are more attracted to the scent of men with dissimilar MHC genes or simiilar MHC genes. MHC genes encode for immune system proteins, and it is thought that the greater variety of MHC genes a person has, the stronger their immune system. The sample consisted of university students, and female university students were tested at the midpoint of their menstrual cycle. Male participants were given new t shirts and asked to wear them to bed for 2 nights, then bring them to he lab. Each woman was given 7 tshirts (3 from men with similar MHC genes to her own, 3 from men with different MHC genes than their own, and a control that hadn't been worn) - this was the IV. The women rated the pleasantness of the odor on a 1-10 scale (unpleasant to pleasant). Women who were not on hormonal contraceptives rated the shirts worn by men with dissimilar MHC genes as more pleasant than those worn by men with similar MHC genes.This provides evidence for sexual selection on female mate preference for males with dissimilar MHC genes, possibly because it might lead to healthier children.

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Describe a study related to techniques to study the brain.

"Maguire et al. 2000. Aim: To investigate whether the hippocampus of London taxi drivers, who have extensive spatial navigation experience, differs structurally from non-taxi drivers.Sample: right-handed male London taxi drivers with over 1.5 years of experience, compared to right-handed male non-taxi drivers matched in age.Method: A quasi experiment using structural MRI scans to analyze hippocampal volumeDescription: Taxi drivers and controls underwent MRI scans; researchers measured gray matter volume (independent variable: occupation; dependent variable: hippocampal structure).Results: Taxi drivers had significantly larger posterior hippocampi and smaller anterior hippocampi compared to controls; a positive correlation was found between the number of years driving taxis and posterior hippocampal volume. Conclusion: The study demonstrates neuroplasticity, as the hippocampus adapts to spatial navigation demands, supporting the role of the posterior hippocampus in memory and spatial navigation while highlighting MRI's efficacy in detecting structural brain changes. (Side note 1: you don't need both Draganski and Maguire - pick your favorite one to study for both neuroplasticity and techniques to study the brain.) (Side note 2: Eleanor Maguire passed away a few days ago at the relatively young age of only 55!)

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