Psyc20006 - Biological Psychology

DA system might be more important in the behavioural/habit and cognitive aspects than the pleasant feeling

They were not able to be left alone

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fMRI (functional magnetic resonance imaging) measures brain activity by detecting changes in blood flow. The temporal resolution of fMRI refers to how quickly it can capture changes in brain activity over time. The correct answer, d. 2000 ms, suggests that the typical temporal resolution of fMRI is 2000 milliseconds, or 2 seconds. This means that fMRI can detect changes in brain activity at a rate of once every 2 seconds.

Drugs will often only activate one or a few receptor subtypes , and will be more selective than natural NT

Heritability refers to the proportion of variance in the phenotype (that is, the trait in question) that is attributable to variance from genes. In this fictional scenario, the key thing to notice is that there is no variation in the environment. This means that all variation in the phenotype must be attributable to genetic variation, which means that heritibility is very high (technically, it is 100%).

This illustrates the broader point that the heritability of a trait is a local measurement—it will depend on how much environmental and genetic variation is actually present in the population you're studying.

Regarding the incorrect responses, zero heritability would be observed in the opposite situation, where all individuals are genetically identical. Certain traits do change in heritability throughout the lifespan (intelligence is one), but in the scenario posed in the question, heritability wouldn't decrease unless variation was introduced into the environment. Similarly, all traits would have the same high heritability, so physical traits would be no more or less heritable than behvioural traits.

First let's look at the correct answer, the one that's not a true feature of GWAS. The second answer (b) is the correct one, but it's a little tricky. Because, in fact, microarray technology is what made genome-wide association studies possible. What makes this NOT a feature of GWAS is that we're not interested in measuring gene expression levels. Rather, we're measuring changes in the genetic code at particular sites right across the genome. If you wanted to measure where and how much of a given protein is expressed (that is, measure gene expression), you wouldn't do a GWAS.

The first answer (a) is a true feature of a GWAS, making it an incorrect answer. We have learned that when we do a genome-wide association study, we do lots of tests. Every time we do a test, there's a chance we'll think we've found an association where there really isn't one. That problem gets much worse when we do hundreds of thousands of tests. In fact, if we applied the usual criteria we'd uncover thousands of associations even when there truly aren't any. We deal with the problem by being extremely strict with our statistical criteria. Incidentally, you've also learned about a similar problem in fMRI.

The third answer (c) describes a feature of a GWAS (making it an incorrect answer). Imputation relies on the fact that nearby SNPs are highly correlated. So by using the genotypes we already have from the SNPs that we have measured directly, we can also try to predict genotypes at SNPs that aren't part of our array.

The final answer (d) also describes a feature of a GWAS (making it an incorrect answer). While the first few GWAS examined around 100 000 genetic markers, modern studies test upwards of half a million.

The CHRNA5-A3-B4 gene cluster encodes subunits of an acetylcholine receptor. Research has shown that variants in this gene cluster are associated with an increased risk of heavy smoking. Acetylcholine receptors play a role in the brain's reward system, and genetic variations in this gene cluster can lead to altered nicotine receptor function, making individuals more susceptible to nicotine addiction and heavy smoking. This association between the gene cluster and heavy smoking has been well-established through numerous studies.

X-linked dominant inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the trait or disorder to be expressed in both males and females, but it is more commonly observed in females. In this inheritance pattern, an affected father will pass the trait to all his daughters, while affected mothers can pass it to both sons and daughters. This mode of inheritance is characterized by the presence of affected individuals in every generation of an affected family, and it can skip generations.

The given statement is incorrect because it states "None" as the answer, implying that there is no incorrect statement among the options provided. However, the third statement is incorrect. It states that the G allele at SNP rs6295 impairs the transcriptional repression of the promoter, thus increasing the expression of the 5-HT1A receptor and the binding potential. In reality, the G allele is associated with increased serotonin binding potential, but it does not impair transcriptional repression.

The given answer states that all of the statements provided are correct. This means that each statement in the question is true. THC is indeed the active compound in marijuana. Nucleosides are produced when nucleic acids are enzymatically broken down. Nucleosides can act as cotransmitters that modulate the modulators. Cannabis is known to have antiemetic properties and can be used to reduce nausea. Therefore, all of the statements are correct.

The explanation for the given correct answer is that Woodman and Luck (1999) conducted a study on the N2pc component of the event-related potential. They found evidence that suggests people search the locations in a visual display in a serial fashion. This means that individuals tend to examine each location one at a time when searching for specific targets in a visual display, rather than searching multiple locations simultaneously.

Schizophrenia is the result of abnormal dopamine signalling. Antipsychotics block the DRD2 dopamine receptors associated with schizophrenia

The given answer states that the signal in EEG is band-pass filtered to remove low (<.5-1hz and high frequencies>35-70Hz) because they do not reflect brain activity. This explanation suggests that the limitation of EEG is not related to the band-pass filtering of the signal, as it is a necessary step to remove frequencies that do not reflect brain activity.

Explicit and implicit memory are distinguished partially on the basis of whether conscious recollection is used. Explicit memory refers to the conscious recollection of information, such as recalling facts or events. It involves deliberate effort and awareness. Implicit memory, on the other hand, is the unconscious or automatic recall of information, such as skills or habits. It does not require conscious recollection or deliberate effort. The distinction between explicit and implicit memory is important in understanding how different types of memory are processed and how they can be affected in amnestic syndromes.

After repeated associations between the reward and the beep, no DA will be released at the reward as the reward is expected, but it will now be released at the beep

AD commences in the hippocampus/Medial Temporal Lobes. It then spreads posteriously to the parietal cortex and then to the frontal cortex

High levels of LC/NA activity can lead to stress, anxiety and panic attacks

Both ion channels and G Protein-coupled receptors are transmembrane proteins that span the cell membrane. G Protein-coupled receptors can influence metabolic processes within a cell via second messenger systems, while ion channels primarily regulate the flow of ions across the cell membrane. G Protein-coupled receptors have a relatively long action compared to ion channels. However, ion channels are generally less selective and can be activated by a variety of neurotransmitters, while G Protein-coupled receptors are more selective and respond to specific ligands.

You should remember that both ChR2 and NpHR are microbial opsins used in optogenetics. The correct answer is the first (a): the ChR2 pump is activated by blue light, and the NpHR pump by yellow light.

The second answer (b) is on the right track, but the correspondences are back-to-front. In fact, ChR2 activation causes neural excitation (makes cells more likely to fire), while NpHR activation causes neural inhibition (makes cells less likely to fire).

The third answer (c) is something of a red herring. Both ChR2 and NpHR are used in optogenetics (and could potentially be delivered as part of a CRISPR-Cas9 system). So this doesn't constitute a difference between them.

And because (b) and (c) are incorrect, (d) must also be incorrect.

Glutamate neurons are known to be relatively long and are responsible for transmitting signals from one area of the brain to another. This means that they play a crucial role in communication between different regions of the brain.

Lower p-values are higher up

The given answer states that the excitability of the primary motor cortex during mental rotation of tools was not significantly enhanced compared to images of houses, 3D- and 2D-figures. This suggests that the brain's response in the primary motor cortex is not specifically tied to mental rotation of tools, but rather is more general in nature. It implies that the primary motor cortex does not show a selective increase in excitability during mental rotation of tools compared to other types of stimuli.

X chromosome inactivation is random in each cell and involves the XIST RNA transcript coating the chromosome to be inactivated and the TSIX RNA transcript that suppresses the transcription of XIST

Neurotransmitters/neuromodulators can influence specific brain functions because there are different receptors located in specific areas of the brain that are sensitive to one type of neurotransmitter/neuromodulator. These receptors can trigger different effects depending on the specific area they are located in. This allows for precise control and modulation of brain functions despite the release of neurotransmitters/neuromodulators throughout the brain.

This is not a correct equation: h2 = G + E + 2covGE, where the covariance and correlation between the genes and the environment is taken into consideration in order to calculate heritability

To determine whether our t-test result is statistically significant when we do not have a directed hypothesis, we need to look up the critical t-value for the correct degrees of freedom in the table for the "proportion of two tails combined" column using the threshold of 0.05. This is because we want to capture 2.5% on each end of the distribution's tail. By comparing our t-value to the critical t-value, we can determine if the result is statistically significant.

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The statement "All of the above" is false because it implies that all the previous statements are false. However, the first two statements are true. The frontal lobes do incorporate primary memory systems, and they are essential for relating arbitrarily related pieces of information. The third statement is also true as damage to the thalamus can result in memory impairment. Therefore, the correct answer is "All of the above" is false.

Synthesis and transport of NT is slow and release of NT is fast 

The higher the emotional response, the more profound the storing of the emotional memory

When the Locus Coeruleus (LC) neurons have a burst of firing in response to an arousing external event, their activity will subsequently become temporarily suppressed. This suppression allows attention to focus on the external stimulus, reducing distraction or competition from other stimuli for attention. Additionally, the burst of firing in LC neurons will result in the widespread release of noradrenaline, which further enhances attention and arousal. Therefore, all of the options mentioned in the answer (a, b, and c) are correct.

The given answer states that none of the statements are incorrect. This means that all of the statements provided in the question are true and accurate.

The given answer, "All of the above," is correct because the passage states that there are specialized areas in the ventral visual system that function as modules for certain objects like faces, houses, places, and body parts. However, it also mentions that most objects are not encoded in modular brain regions. Additionally, the passage suggests that the modular brain regions coding for specific objects may serve purposes beyond just processing specific object categories. Therefore, all of the statements mentioned in the answer are supported by the information provided in the passage.

The correct answer, "Indicated that episodic memory and semantic memory can show a single dissociation in performance during encoding," suggests that Vargha-Khadem's research demonstrated that there can be a difference in how episodic memory and semantic memory function during the encoding process. This implies that the two types of memory can be dissociated and have separate performance levels when it comes to encoding information.

Unmasking a mask requires timing the single TMS stimulation to 60-140ms after the mask, you still see the mask, you just do not process it. Schizophrenics have a reduced Cortical Silencing Period (CSP), meaning that the cooling off period is reduced after excitation and thus there is hyperexcitability.

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Again, let's look at the correct answer first. That's the third answer, (c). Those who thought addition was a type of structural variant might have been thinking of an 'insertion' or 'insertion-deletion' variant. That's when some people have a stretch of DNA that is simply missing in others.

Perhaps the trickiest variant is the first answer (a), inversion. Here, the DNA is switched around so that not only is the sequence reversed, but the two strands of the double helix are swapped as well.

The second answer (b), a copy-number variant, refers to when a short stretch of DNA is repeated over and over; some people might have no repeats, some might have many. Recall that in Lecture 2, we learned that a copy-number variant (in this case, 200 or more copies of a CGG sequence of bases) is responsible for fragile X syndrome.

The final answer (d), a block-substitution variant, is a bit like a single-nucleotide polymorphism (SNP). But in a block-substitution variant, a whole sequence of DNA is present in some people, and a whole different sequence is present in others.

Dementia of the Alzheimer's type (DAT) refers to the dementing syndrome that is associated with Alzheimer's disease. This means that individuals with Alzheimer's disease may experience symptoms of dementia, such as memory loss, cognitive decline, and changes in behavior. It is important to note that DAT cannot be diagnosed during life, as it requires postmortem examination of the brain to confirm the presence of characteristic plaques and tangles. While there are treatments available to manage the symptoms of Alzheimer's disease, such as anti-epileptic drugs, there is currently no cure for the condition. The statement that DAT is the process of normal aging sped up is incorrect, as Alzheimer's disease is a distinct neurological disorder.

Fragile X syndrome acquires its name from the appearance of the chromosome itself: We see a constriction on the long arm of the chromosome. This would be visibile in a karyotype map of the kind we saw in Lectures 1 and 2. So the correct answer is the second one (b).

The first answer (a), a Manhattan plot, is the way we visualise results of a genome-wide association study. The third (b), a pedigree chart, is the family-tree-like map we use to trace a trait through generations. It would be possible to create a pedigree chart for fragile-X syndrome, but it wouldn't let you see the genetic mutation. The final answer (d), a PET scan, refers to the technology that you can use to estimate the density of specific receptors in neural tissue. It wouldn't allow you to see the genetic mutation in fragile-X syndrome.

See Lecture 1, Slide 46 & Lecture 2, Slides 9, 11, 13, 19, 31 (Manhattan plot); Lecture 1, Slides 22–23 & Lecture 2, Slide 2 (karyotype map); Lecture 1, Slides 32–35 (pedigree chart); Lecture 3, Slides 8–11, 16 (PET scan).

Protonopia (colour blindness) is X linked recessive

First, you need to remember that CRISPR-Cas9 is a technology that can be used to selectively edit an organism's genome. Then, you need to consider what each of these studies involves. The first answer (a), forward-genetic studies, is incorrect. In forward-genetic studies, researchers are initially focused on the phenotype (that is, trait) of interest. It will likely involve deliberately introducing genetic changes, but these will be random changes most probably caused by radiation. Once a strain of animals exhibiting the phenotype is established, the researchers will then search for genetic differences between unaffected and affected animals.

The second answer (b), was the correct one. In reverse-genetic studies, researchers are initially focused on the genotype of interest. That gene is silenced, or altered in some way, and the study will then characterise the phenotypic consequences of the genetic change.

The third answer (c), genome-wide association studies (GWAS), is incorrect. GWAS rely on natural variation in a population, and don't require gene-editing technologies.

And you can deduce that the final answer (d) is incorrect, because (a) is incorrect.

The systems are entirely parallel within declarative memory, which is dependent on the hippocampal system. Therefore, damage to the hippocampal system leads to the equal impairment of both the memory systems. Therefore, the systems are non-dissociable. (Squire and Zola)

Autosomal recessive inheritance occurs when an individual inherits two copies of a recessive allele, one from each parent. This means that both parents are carriers of the recessive allele but do not show the trait themselves. In autosomal recessive conditions, individuals must have two copies of the recessive allele to express the trait. If only one copy is inherited, the individual is a carrier but does not show any symptoms. This mode of inheritance is commonly seen in conditions such as cystic fibrosis and sickle cell anemia.

The given answer is not informed by the analysis of HM because it does not specifically mention or discuss HM's case or the impact of his medial temporal lobe damage on memory function. The answer focuses on the general concept of intact memory function and the involvement of various brain regions, but it does not address the specific case of HM and the significance of his medial temporal lobe structures in memory.

There is much controversy between glutamate and psychosis, and it is more likely that other NT like dopamine are the cause

Opiates include morphine, heroine and opium, endogenous means naturally occurring. Peptides are the product of larger compounds being broken down in neurons before being released at the terminal buttons. Opiates are used for their analgesic affects (pain relief)

At least 5 symptoms from DSM V must be present within a two week period in order to be diagnosed with depression

The effects of alcohol on memory loss and sedation, is a result of the antagonistic effects of alcohol on glutamate

Fragile X syndrome involves a Copy Number Variant mutation involving a CGG sequence in the promotor of the FMR1 gene, which is critical to synaptic plasticity. The mutation triggers DNA methylation, which constricts the promotor region of the X chromosome and prevents transcription.

The hippocampus is also known as Cornu ammonis and can be labelled CA1 to CA3

Dense amnesic syndrome is associated with damage to the mammillo-thalamic tract, as it connects to the anterior thalamus and hippocampus

The correct answer is that all of the above alternative theories could explain the findings by Kanwisher et al. (1997). The fusiform face area could be recruited when we become experts for something, such as faces. It could also be recruited depending on resolution needs, as faces usually appear in the center where we can perceive the greatest detail. Additionally, the activation profile of the fusiform face area could reflect a combination of face processing, eccentricity coding, and activation related to expertise.

For something to be addictive you must code losses as less significant than gains

Folding within the brain (sulci) destroy signals, therefore there is not an accurate representation

The given answer states that all of the statements provided are correct. This means that each neurotransmitter mentioned (serotonin, noradrenaline, dopamine, acetylcholine, and histamine) is indeed synthesized in the specified areas and released to the mentioned regions of the brain. Additionally, the location of the histamine neurons is correctly stated as being in the posterior hypothalamus. Therefore, all of the statements provided in the question are accurate.

Averaging signals from many trials is required to calculate the event-related potential (ERP) because EEG signals from single trials are very noisy. The average amplitude is not necessarily greater than any single trial amplitude.

The given correct answer states that all three options - No dissociation, Single Dissociation, and Double Dissociation - are correct. This means that in the given system with X and Y parts producing A and B outcomes, all three scenarios can occur. In the case of no dissociation, damaging either X or Y will affect both A and B equally. In single dissociation, damaging X affects A but not B, while damaging Y affects both A and B. In double dissociation, damaging X affects A but not B, and damaging Y affects B but not A. This suggests that the memory systems in this scenario can exhibit different levels of independence from each other.

Declarative memory is not of semantic knowledge i.e. how to perform a task. Declarative memory refers to the ability to consciously remember facts and events. It involves the storage and retrieval of information that can be explicitly stated or declared. Semantic memory, on the other hand, is a type of declarative memory that involves general knowledge and concepts. It is not specifically related to how to perform a task.

When the RF pulse is switched off the transversal magnetisation decays and the longitudinal magnetisation is re-established. This is known as the "relaxation" phase

Artefact rejection and occular correction are necessary steps to clean the raw signal in order to remove any unwanted noise or interference caused by eye movements or blinking. Event related potentials, which involve measuring brain responses to specific stimuli, typically require multiple trials to obtain reliable results. Therefore, options A and D are correct. Option B is incorrect because sweating and electrical noise can indeed affect the signal quality. Option C is incorrect because mathematical algorithms can remove most noise and artefacts, but they may not be able to completely eliminate noise caused by muscle clenching.

The bottom of the equation refers to the standard mean of the sample

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The given answer states that a limitation of fMRI is that although we interpret the results correctly, it is not clear whether we have accounted for extraneous variables. This means that while we may be able to accurately interpret the brain activity shown in an fMRI scan, there is still a possibility that other factors or variables outside of the study's control could be influencing the results. This highlights a potential limitation in the accuracy and reliability of fMRI findings, as there may be confounding factors that have not been taken into consideration.

The correct answer is the first (a): CRISPR-Cas9 is a mechanism borrowed from bacteria, one they use to defend against invading viruses. This was explained in the video in Lecture 3.

The second answer (b) and third answer (c) have mixed up a couple of the components. The system contains both the Cas9 protein and guide RNA. But the RNA is used to locate the desired DNA sequence (at which the Cas9 protein cuts). And because (b) and (c) are incorrect, we know that (d) must also be incorrect.

Carbon monoxide is a poisonous gas that can be deadly when inhaled in high concentrations. It binds to hemoglobin in the blood, reducing its ability to carry oxygen to the body's tissues. In contrast to carbon monoxide, nitric oxide is a signaling molecule in the cardiovascular system. It is involved in dilating blood vessels in active brain regions, which is important for learning and memory. Nitric oxide is synthesized, short-lived, and diffuses immediately, and it does not activate receptors. Therefore, the statement that carbon monoxide is deadly and cannot be utilized in the brain is incorrect.

The correct answer is "Maintaining information over time, in one's mind." This definition accurately describes memory as the process of retaining and storing information in one's mind for later use or retrieval. It implies that memory involves the ability to hold onto and recall information over a period of time, suggesting that it is a cognitive function related to the storage and retrieval of knowledge or experiences.

Monoamine Oxidase Inhibitors can have detrimental affects if a lot of tryptophan is consumed after ingesting the drug

Fourier transformation allows for the measurement and reconstruction of the 3D brain, but takes 1-3 seconds

Absence of a G allele leads to the repression of HTR1A transcription, decreased receptor density (indexed by BP), high amygdala reactivity and a predisposition to high anxiety

The answer is incorrect because it states that if a brain region is activated by many cognitive functions, we learn very little about it. However, the explanation provided in the question suggests that if the experimental setup successfully manipulates the cognitive process of interest, it can still provide useful information about the process. Therefore, even if a brain region is activated by multiple cognitive functions, it can still contribute to our understanding of a specific cognitive process if the experimental setup is effective.

Tulving's Model of Memory (1972-2001): From lesion studies. utilised Atkinson-Shiffron model. Separated LTM into components: procedural, episodic and semantic.

Declarative memory impairment is most reliable when the hippocampus or the Anterior Thalamic Nuclei are lesioned

The greater the ERN, the higher the probability to get it right on the next trial. This is because the ERN is a negative deflection in amplitude that occurs after an erroneous response. It reflects the brain's detection of an error and the subsequent adjustment in behavior. Therefore, a larger ERN indicates a stronger response to errors and a higher likelihood of correcting them on the next trial. Additionally, the statement suggests that a greater ERN is associated with a lower response force to try and correct the error, implying that the brain's automatic error monitoring system is more effective in guiding behavior than conscious effort.

Episodic memory relies on the hippocampal circuit. This means that the hippocampus plays a crucial role in the formation and retrieval of episodic memories. The hippocampus helps in encoding and consolidating episodic memories, as well as in retrieving them when needed. Therefore, the correct answer is that episodic memory relies on the hippocampal circuit.

The key reasoning behind the endophenotype approach is that it should be likely to have a more direct relationship to the underlying genetic mechanisms than the disorder itself. So the third answer (c) is correct.

The first answer (a) is incorrect. As we've learned, part of what makes endophenotypes useful is that we can measure them in psychologically normal individuals. Of course, the endophenotype should be associated with the disorder, but it needn't be present only in affected individuals.

The second answer (b) is also incorrect. This would be a compelling discovery, but it's not necessary that an endophenotype is responsive to the same therapies as the disorder itself.

Finally, as (a) and (b) are incorrect, we can deduce that (d) is incorrect.

Phase 1 lasts 2-3 years and includes the following symptoms: failing memory, muddled inefficiency in Activities of Daily Living. Spatial disorientation and mood disturbances.

LC likely to play the same role  in perceptual and cognitive decisions as they are believed to play in behaviour

Neurofibrillary tangles lie within the neuron and contain amyloid. Amyloid proteins are found in senile plaques

Surgical removal of the lesioned hippocampus can cure or reduce the number of seizures.

The hippocampal formation is necessary in relational memories between two arbitrary pieces of information.

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The answer suggests that the probability of learning from fMRI results and the over-interpretation of null results depend on various factors such as the quality of the task to measure the cognitive process and the specificity of the region for that process. Additionally, it states that when the null hypothesis is accepted, the significance is unknown because statistical tests are designed to make the alternative hypothesis difficult to support, rather than the null hypothesis. Therefore, the answer implies that only a few neurons in a voxel may be showing differences that can only be detected through more sensitive tasks.

Unmasking a mask requires timing the single TMS stimulation to 60-140ms after the mask, you still see the mask, you just do not process it. Schizophrenics have a reduced Cortical Silencing Period (CSP), meaning that the cooling off period is reduced after excitation and thus there is hyperexcitability.

Neuromodulation alters neurotransmitter release at the pre synaptic neuron and neurotransmitter action at the post synaptic neuron