1.1
This statistical term refers to the proportion of variation among individuals in a group that we can attribute to genes, rather than the percentage of a trait inherited by an individual.
What is heritability?
The central nervous system consists of only these two anatomical structures.
What are the brain and spinal cord?
These branching extensions of a neuron receive incoming chemical signals from neighboring cells and conduct them toward the cell body.
What are dendrites?
Located at the base of the brainstem, this structure controls vital, involuntary survival functions such as heart rate and breathing.
What is the medulla?
If a researcher reports that the heritability of height is 80%, this does NOT mean an individual gets 80% of their height from genes; rather, it means that 80% of the differences in height across a given group are due to this factor.
What is Heritability?
Studies of these twins, who share 100% of their genetic material, are often used to isolate the effects of nature versus nurture.
What are identical (or monozygotic) twins?
This branch of the autonomic nervous system is responsible for the "rest and digest" response, slowing heart rate and stimulating digestion.
What is the parasympathetic nervous system?
This fatty layer insulates the axon and accelerates the speed of electrical signal transmission down the neuron.
What is the myelin sheath?
Known as the brain's sensory control center or relay station, this structure routes incoming sensory information (except smell) to the appropriate areas of the cerebral cortex.
What is the thalamus?
In a split-brain patient, an image of an apple is flashed exclusively to their left visual field. Because information travels to the right hemisphere, the patient cannot name the object verbally, but can select the physical apple using this hand.
What is the left hand?
If identical twins raised apart turn out to have nearly identical IQ scores, this suggests that intelligence is heavily influenced by this side of the nature vs. nurture debate.
What is nature (or genetics)?
When you are startled by a sudden loud noise, this branch of the autonomic nervous system triggers your "fight-or-flight" response by accelerating your heart rate and dilating your pupils.
What is the sympathetic nervous system?
This principle dictates that a neuron either fires completely or does not fire at all; a stronger stimulus only increases the frequency of firing, not the signal's speed or strength.
What is the all-or-none response?
Often called the "little brain," this structure sits at the rear of the brainstem and coordinates voluntary movement, balance, and procedural (implicit) memory.
What is the cerebellum?
A runner completes a marathon and reports feeling a sudden "runner's high" along with a reduced sensation of pain in their leg muscles. This phenomenon is primarily caused by the brain releasing these natural pain-relieving chemical messengers.
What are endorphins?
Identical twins raised apart in completely different households and cultures still show remarkably similar scores on tests measuring this cognitive trait, proving a strong genetic component.
What is intelligence (or IQ)?
Voluntary control of our skeletal muscles is governed by this subdivision of the peripheral nervous system.
What is the somatic nervous system?
During an action potential, the rapid inward rush of these positively charged ions across the axon membrane causes depolarization.
What are sodium ions?
Located in the left frontal lobe, damage to this specific region impairs a person's ability to produce spoken language, resulting in slow, labored speech.
What is Broca's area?
After a stroke, Phineas struggles to comprehend spoken language and produces fluent, grammatical sentences that make no logical sense ("word salad"). Damage occurred in this area of his left temporal lobe.
What is Wernicke's area?
A psychologist studies a group of people living in wildly different environments and finds a low heritability score for trait X. This indicates that variance in trait X is primarily caused by this.
What is environmental differences?
Simple reflex actions (like pulling your hand off a hot stove) occur almost instantly because the signal is processed in this structure before reaching the brain.
What is the spinal cord?
Immediately after a neuron fires, it enters this brief recovery period during which it repolarizes and cannot fire another action potential until reset.
What is the refractory period?
This thick band of neural fibers connects the left and right cerebral hemispheres, allowing them to communicate; it is surgically severed in split-brain patients to treat severe epilepsy.
What is the corpus callosum?
Selective Serotonin Reuptake Inhibitors (SSRIs) used to treat depression work by blocking terminal buttons from reabsorbing serotonin from the synaptic gap. By preventing this specific cellular process, SSRIs allow serotonin to remain active in the synapse longer to bind with post-synaptic receptors.
What is reuptake?