PSYC2015 Final Exam Content Flashcards
What are Tinberg’s 4 questions about the causes of behaviour?
Causation - hormones, genes etc.
Development - imprinting, issues of learning etc.
Evolution - e.g parental care in birds but not most reptiles
Function - the contribution of the behaviour to fitness
Describe Darwin’s theory of evolution by natural selection
- Limited resources = competition
- Survival of the fittest
What is meant by fitness?
The reproductive success of an animal relative to direct competitors in the population
What are SSDR’s and how do they increase fitness
SSDR -> Species-specific defense responses
- Increased survival = increased fitness
Explain how one psychological trait could have been shaped into its present form via natural selection
Aggression -> increased competition for resources leading to increased fitness
Explain the differences between adaptations, exaptations, spandrels, by-products & noise
Adaptations - An inherited characteristic that emerged through natural selection as it contributed to fitness
Spandrels/By-products - Traits that don’t affect fitness but are linked to other adaptations (e.g. human chins)
Noise - Random variation in a trait that doesn’t affect fitness
Exaptations “Co-adaptations” - A characteristic that didn’t arise as an adaptation, but was later co-opted for its function
How does inclusive fitness and reciprocation solve the problem of altruism and other prosocial instincts
Lose something of low value to you by altruism but later gain something of high value to you by reciprocation
- This increases the collective fitness of the population
What is the social theory of intelligence in evolution
- A socially demanding context
- Development of general problem-solving skills in order to:
- Maximise personal fitness in this context
Examples:
- Remembering personal interactions
- Deception
- Planning
- Arguing and getting your way
What is the theory of sexual selection, what sort of traits are selected for this process
- Selection pressure on traits of health and parental investment
Physical traits - signalling health, determining attractiveness
Behavioural traits - signalling competitiveness & parental investment
Describe how twins and siblings can be compared to estimate the heritability of traits
Differences in correlations for some phenotype between siblings/twins -> used to estimate genetic variability (A) & environmental variability (C)
R(MZa)/R(MZt) = A/(A+C)
- If poor involvement of environment, approaches 1
- If large involvement of environment, approaches 0.5 or lower
Describe the quantitative genetic analysis approach to studying psychological traits and the problems associated with it
- Quantitatively characterise a behavioural phenotype in a given population
- Examine the changes in the phenotype distribution in sets of progeny
- Statistically infer the number of genes responsible for the phenotype
- If phenotype was due to one gene, it would sort itself into a Mendellian inheritance pattern
- E.g., rats good at maze and rats bad at maze bred together
Problems:
- Results do not identify individual genes
- Necessity for large pedigrees & cross-mating makes human studies unlikely
Describe the single gene approach to studying psychological traits and the problems associated with it
- Some phenotypes have neurobiological bases (e.g., alcohol dehydrogenase for alcoholism)
- To test -> test people with multiple alleles of the gene
- E.g., people with “Met/Met” allele had better working memory than those with “Met/Val” & “Val/Val” genotypes
Problems:
- Ignores epistasis (the background contribution of other genes)
- Redundancy & Pleiotrophy
Describe the 4 main points at which genetic activity can be modulated by environmental factors
- Transcriptional control - onset of transciption
- Translational control - translation rate & mRNA lifespan
- Post-translational control - protein activation, feedback inhibition (protein inhibits transcription of its own gene)
- Natural selection of phenotype
Describe the 4 models of gene-environment interactions
- Genetic and environmental effects might be independent but additive
- Some environmental effects might only be seen under certain genetic conditions
- Some genetic effects might only be seen in certain environments
- Some genetic effects might influence the environment to which an individual is exposed (alcoholics having alcohol in the house)
Describe the epigenetic modification of gene expression
Where the environment changes the functional genotype of the cell
- The DNA is not altered
- It is chemically modified to be expressed more/less
Describe the non-genetic processes and mechanisms by which maternal care patterns can be inherited from generation to generation
E.g., arched-back nursing and licking & grooming in rodent dams produce offspring that are less fearful
How do nerves communicate with each other across synapses
- Action potential travels down the axon
- Releases vesicles of neurotransmitters into the synaptic gap
- Neurotransmitters bind to receptors on the post-synaptic neuron
- Change in form causes membrane to reach threshold
- Another action potential is caused
What is the rate law and what is spatial & temporal summation
Rate law- the strength of a stimulus is represented by the rate of firing of an axon
Temporal summation - sufficiently fast inputs from one neuron
Spatial summation - synchronised inputs from multiple synapses in a small region
What are the different types of neurotransmitters
Cholines - Acetylcholine (bind to nicotinic receptors)
Lipids - Anandamides (bind to cannabanoid receptors)
Amino acids - Glutamate & GABA
Monoamines - Dopamine, Noradrenaline, Serotonin
Peptides - Endorphins (bind to opioid receptors)
Nucleosides - Adenosine
What are the different ways in which drugs can act as agonists and antagonists
Agonists:
- Drug that mimics an NT & activates an action potential
- Enhance the release of NT
- Blocking the reuptake of NT
- Blocking enzymes that destroy NT
Antagonists:
- Blocks the post-synaptic receptors to stop action potentials from occurring
- Opposite of agonist
What chemical systems do these drugs affect;
nicotine, cocaine, amphetamine, heroin, ecstasy, alcohol
Nicotine - Acetylcholines Cocaine - Dopamine Amphetamine - Dopamine Heroin - Endorphins Ecstasy - Serotonin Alcohol - GABA
What neurochemical systems do these drugs affect and what are they mostly used for clinically;
ritalin, antipsychotics, benzodiazepines, SNRIs, SSRIs, beta-blockers, donezipil, morphine, ketamine, cannabidiol
Ritalin - dopamine, ADHD
Antipsychotics. - dopamine, schizophrenia
Benzodiazepines - GABA, sedatives
SNRIs - noradrenaline, depression
SSRIs - serotonin, depression
Beta-blockers - noradrenaline, heart problems/anxiety
Donezipil - acetylcholines, dementia
Morphine - endorphins, painkiller
Ketamine - glutamate, sedative
Cannabidiol - anandamides, epilepsy, Parkinson’s
What do these terms mean;
Homeostasis, distress, eustress
Homeostasis - the body’s tendency towards a stable equilibrium
Distress - Stress with negative implications
Eustress - Stress that is beneficial to health
Describe the sympathetic and parasympathetic nervous system response to stress and how they are regulated
Sympathetic system - stimulates tissues, dilates pupils, elevates heart rate etc.
Parasympathetic system - “calms everything back down”, opposite effects to the sympathetic system
Regulation:
Alpha 2 autoreceptors uptake NA from the synaptic gap
Describe the central noradrenergic response to stress
Central noradrenergic = Brain
- Locus coeruleus (LC) activity is associated with arousal, vigilance and reaction speed
- LC activity increased when in fear/pain
- Also important for memory, attention and sensory processing
Describe the HPA axis and how it is regulated
Hypothalamus-pituitary-adrenal axis
- Hypothalamus releases CRH, which travel to the anterior pituitary
- Anterior pituitary releases ACTH, which travels to the adrenal glands
- Adrenal glands release glucocorticoids
- Positive feedback loop (CRH -> noradrenaline -> CRH)
Regulation:
Stimulation of glucocorticoid receptors, inhibiting the HPA axis
Describe the pattern and effects of HPA axis activation in depression
- Depression is associated with chronically elevated levels of glucocorticoids
- Caused by a loss of negative feedback inhibition over the HPA axis
- Hippocampus is smaller in people with depression
Describe Schacter and Singer’s two-factor theory of emotion
- Perception of fearful stimuli
- Acitvation of sympathetic nervous system
- Awareness of psychological state/arousal
- Cognitive appraisal of the situation to determine the most appropriate emotion
