Physiological & Behavioral Neuroscience - GRE Subject Test: Psychology

The corpus callosum is a wide set of nerve fibers that connects the two hemispheres of the human brain. Agenesis of the corpus callosum, a rare birth defect, results in impaired cognitive abilities (e.g. key processes like face processing and other socially-important skills).

In order to examine brain functions, researchers must examine living individuals, rather than the brains of cadavers. This poses several challenges. Sometimes, animal brains are studied using invasive techniques that would be unethical to perform on human subjects. In order to mitigate these challenges and study brain activities, researchers in psychology have developed several noninvasive techniques including PET scans, MRIs, and electroencephalograms.

The correct answer is frontal lobe. The frontal lobe is responsible for reward, attention, short-term memory tasks, planning, and motivation. It is also the part that tells a person if they are making a good decision or not. If the frontal lobe is injured, people may not realize they are behaving socially unacceptably. The other choices are incorrect. The parietal lobe is responsible for processing sensory information from your environment. The occipital lobe is responsible for eyesight processing. The temporal lobe is responsible for hearing and memory input. Last, the anterior lobe does not exist.

The rCBF refers to the regional cerebral blood flow, a noninvasive procedure that detects broad patterns of neural activity based on increased flow to different brain areas. CAT scans, PET scans, and MRIs are all computerized scanning techniques but not specialized to test blood flow in the brain.

The hippocampus—located in the brain's temporal lobe—is the center for making, storing, and retrieving memories. Damage to this particular area is likely to result in difficulty with one or all of these memory-related processes.

Acetylcholine or aka ACH is the neurotransmitter that is released from the axon terminal to through the neuromuscular junction across the synaptic cleft.

While each of the other options is involved in the release and/or inhibition of hormones (including the hypothalamus, which produces hormones that direct the rest of the endocrine system), the pons function as a relayer of messages from the cortex and the cerebellum.

Oxytocin and vasopressin receptors are more prevalent in prairie voles who have a pair-bond than in those who've yet to mate, indicating higher releases of those two neurotransmitters in monogamous prairie voles--prairie voles which are considered promiscuous, when does with both of these neurotransmitters, become monogamous.

This scenario is an example of a fight or flight response. Epinephrine is the only hormone listed here that is involved in this response. Another correct answer, not listed, would be norepinephrine. The other choices are incorrect. Acetylcholine is responsible for the "rest and digest" response. Dopamine is responsible for the body's reward system. Neostigmine is a drug that acts like acetylcholine. Last, estrogen is a female sex hormone.

Relaxation indicates that the body possesses a high level of acetylcholine. This is know as the "rest and digest" stage. Epinephrine and norepinephrine perform the opposite task of acetylcholine and are "fight or flight" neurotransmitters. Last, dopamine is a pleasure hormone

The nucleus accumbens has long since been considered a key anatomical structure in the body's reward and reinforcement system. It is one of the key producers and regulators of neural dopamine, and has been linked to several different addictive behaviors—including addictive reinforcement from food, sex, drugs, music, and maternal behavior. It is considered part of the "pleasure center" for the brain due to its release of reinforcing dopamine.

The parietal lobe is responsible of the sensory integration of taste, temperature, and touch. If someone damages their parietal lobe, then they will experience difficulty with sensory integration.

Physiological testing (e.g. blood screenings, radiologic scans and hormonal level measures) have shown that in male primates including humans, cortisol and stress levels have a moderate positive correlation, whereas this correlation is weakly negative in females of the same species.

Remember that typical antipsychotics refer to the first generation of antipsychotics, while atypical antipsychotics refer to the second generation of antipsychotics. Both typical and atypical antipsychotics block dopamine pathways, but many atypical antipsychotics also block seratonin pathways. The other listed neurotransmitters are not associated with psychosis.

While SSRIs can be utilized to treat multiple disorders, it is primarily used in the treatment of depression. Depression is thought to be caused by low serotonin release, and SSRIs prevent the re-uptake and subsequent breakdown of serotonin. Antisocial Personality Disorder, previously known as Psychopathy, has no known treatment though group therapy can be utilized. ADHD is primarily treated with methylphenidates (ex. Ritalin) or amphetamines (ex. Adderall). BPD is treated with cognitive behavioral therapy (CBT).

The mechanism behind the refractory period—formally known as the after-hyperpolarization—for an action potential is not yet well understood, but is thought to be a built-in defense against sodium ion overload inside the voltage gate of a cell membrane.

This can seem like a "which is the best response" type of question where more than one of these choices could be correct. Do not be fooled. The exchange of information or "impulses" in which dendrites and axons are involved is straightforward. Axons send out neural "messages" and dendrites receive. Sometimes it can be helpful to use a mnemonic device to remember: Axon has four letters like send. Dendrite has eight letters like receives.

An action potential describes the event of an electrical impulse being activated by a given neuron once it is sufficiently polarized. We may think of an experience such as pain. If I prick my finger with a needle, I feel a small amount of pain. If, however, I unfortunately lose my fingertip due to a mechanical accident of some sort, I will feel much more pain. This difference in pain is not due to the strength of any one given action potential. An action potential either leads to an electrical impulse or it does not (in other words, it is all-or-none). There are no gradients in strength or degree; however, the number of action potentials occurring across neurons can have a cumulative effect (e.g., greater number of nerve cells involved in the more serious injury of losing a finger tip equates to a greater experience of pain).

The tiny space between a synapse of one neuron and the synapse of another is called the synaptic gap. It is also known as the synaptic cleft. It is in this space where neurotransmitters can be exchanged between neurons. It is important to note that not all neurotransmitter molecules emitted by a given synapse or necessarily received by the synapse across the synaptic gap. Multiple variables are at play. The gap is not needed for the neurons to have space to grow nor is the brain kept moist via these clefts.