Explanation​:
A, B and C are functions of the MRI, whereas D is the function of the positron emission tomography (PET) scans.

MRI scans use magnetic fields and radio waves to produce 3D computer-generated images. All metal objects and clothing on the body have to be removed before lying in the MRI machine. This is a disadvantage of the technique, as people with metallic implants cannot use this technique.

Explanation​:
Pheromones are chemical messengers used for communication among the same species. There is evidence for the existence of pheromones, and there is evidence that shows that pheromones don’t affect behaviour.

A few common critical evaluation points found in the research done for pheromones are - population validity, construct validity, ethics, demand characteristics as most research is for a self-selected sample, lack of internal validity due to the effect of extraneous variables, replicability because the nature of human behaviour is constantly changing.

Explanation​:
Neurotransmitters are released from the presynaptic terminal of a neuron. The presynaptic terminal is the end of the axon, specifically the terminal bouton or synaptic knob, where the neuron forms synapses with other neurons or target cells. Once an action potential reaches the presynaptic terminal, neurotransmitters are released into the synaptic cleft, the small gap between the presynaptic neuron and the postsynaptic neuron or target cell. The neurotransmitters can bind to receptors on the postsynaptic neuron or target cell, transmitting the signal and facilitating communication between neurons.

Explanation​:
Evolutionary explanations for behaviour can also be linked to emotional processing. There is an influence of emotion on cognition and behaviour. LeDoux (1996) described two physiological pathways of emotions - processing fear stimuli. The evolutionary meaning of this is that the brain is wired to produce an automatic quick reaction to fear stimuli linked to the principles of natural selection (survival instinct).

Explanation​:
The phenomenon where genetic predisposition causes individuals to select environments that affect their behaviours is called niche picking. Individuals seek our particular/specific environments based on their experiences. For example - a student showing symptoms of borderline depression will choose complicated options where they are not likely to succeed, such as demanding environments causing stress.

Explanation​:

The modern theory of evolution is based on the following premise:

• organisms are driven by the need to survive and reproduce
• organisms having different traits are adapted to their environment to varying degrees, or what is called differential fitness
• organisms that adapt well to environmental changes have a higher chance of survival

Explanation​:
Research on depression suggests that heritability of depression is a result of both genetic and environmental factors (Caspi et al., 2003). Genetic factors contribute to individual differences in depression, and environmental factors contribute.

Explanation​:

Answer C is correct. The study of genetic adaptations of behaviours and other psychological traits is a focus of evolutionary psychology.

Answers A, B, and D do not focus on genetics, evolution, or adaptation.

Explanation​:
Molecular genetics studies use modern technology for genetic mapping and identifying the alleles of particular genes in a particular individual. Genetic variants are then correlated with observed behaviour. These methods are commonly used to identify specific genes responsible for specific behaviour. For example, the gene that causes depression, the gene that causes aggression.

Explanation​:

A, B and D are functions of the MRI and fMRI.

The difference between the MRI and fMRI is C, the ability to produce a video representation of brain activity over time, which a normal MRI cannot do.

MRI scans use magnetic fields and radio waves to produce 3D computer-generated images.

Explanation​:
Twin studies are small in sample size and rare due to the uniqueness of their target group. It becomes difficult to collect samples depending on the aim of the research. Twin studies are on monozygotic or dizygotic twins or both. This results in issues with the replication of similar studies.

Options A, B and C are strengths of twin studies.

Explanation​:

Stress hormones such as adrenaline and cortisol released after an event activates the amygdala often linked to the formation of flashbulb memories.

Choices B, C and A are hormones but are not related to the amygdala.

Explanation​:
The study done by Maguire et al. (2000) used an MRI scan to study the changes in the brain of taxi drivers in London.

They selected 16 taxi drivers and 50 non-taxi drivers for the study and scanned the brains of all the participants using the MRI. With the help of the MRI scan, they found that the posterior hippocampus was more prominent in taxi drivers compared to non-taxi drivers. The hippocampus is often associated with spatial memory - the ability to remember directions and places.

Explanation​:
Vasopressin has been found to play a role in stable, long-term pair bonding in prairie voles. Prairie voles are rodents who actively select mates, are monogamous, share parenting and are characterised by long-term pair bonds.

These social characteristics found in them, along with similar brain structures and neurochemical make-up, make them a perfect sample to study social behaviour in humans.

Explanation​:
The limbic system is an older subcortical structure of the brain. It is commonly called the “emotional brain” and includes several parts like the thalamus, hypothalamus, amygdala, and hippocampus. It is located on both sides of the thalamus, beneath the medial temporal lobe of the cerebrum.

It supports various functions such as emotion, behaviour and long-term memory.

Additionally, the amygdala, together with the hippocampus, are both involved in emotion and cognition as they are central to processing emotion in relation to cognitive processes such as memory.

Explanation​:
Antagonists counteract neurotransmitters and prevent a signal from being passed further. It decreases the activation of a synaptic receptor by blocking the neurotransmitters from binding/bonding. An example of an antagonist is scopolamine, which affects the neurotransmitter Acetylcholine (ACh).

Explanation​:
Synaptogenesis is an explosion of synaptic formation between neurons during early brain development. The brain experiences a lot of growth during infancy. This period of synaptogenesis plays an essential role in learning, memory formation. Active synapses are strengthened, and less active synapses are weakened. The process of removing the irrelevant/pruned synapses is referred to as synaptic pruning.

Explanation​:
Split-brain studies represent research on brain lateralisation which is the division of functions between the two hemispheres of the cortex. Lateralization is a particular case of localization. Roger Sperry conducted initial animal research to understand this phenomenon.

Explanation​:
Regulation of gene expression results in epigenetic changes, which mean deviation of phenotypes from the genetic code in the DNA sequence. Epigenetic changes can be attributed to environmental factors explaining how nurture influences nature in certain situations. Epigenetic changes can affect the growth of neurons in a baby’s developing brain and brain activity in adults. They result in a change of behaviour in individuals.

Explanation​:
EEG - Electroencephalography measures the electric potentials generated by the neural circuits; neurons here interact with each other by sending electrical impulses. In this method, electrodes are attached to the scalp and pick up the changes in the electric potential of the scalp areas. EEG has a perfect temporal resolution and can detect changes in brain activity within milliseconds. Because of this, it outperforms techniques such as fMRI.

Explanation​:
Cortical remapping, or cortical reorganization, is the ability of one part of the brain area to assume the functions of another part of the brain in case of an injury.

Cortical remapping is explained in the research by Merzenich et al. (1984) on eight adult owl monkeys. The middle finger of the monkey was amputated, and remapping was observed in 62 days. Adjacent areas from other fingers spread and occupied the parts of the unused area / amputated area.

Explanation​:
The nervous system comprises neurons consisting of soma, dendrites, and axons. A synapse or synaptic gap is the space between two neurons. An action potential is a process in which one neuron sends a message to the other neurons through an axon. An action potential is an all-or-none phenomenon. When it reaches the end of the axon, a neurotransmitter is released in the synaptic gap from the axon terminals.

Explanation​:
Serotonin is a neurotransmitter responsible for regulating essential bodily functions, including mood, sleep, and learning and memory processes. It acts as a chemical messenger and passes messages from the brain to the rest of the body. Serotonin deficiency can result in depressive symptoms and anxiety in people.