Biological Bases of Behavior Flashcards

What technique uses magnetic fields and radio waves to produce detailed images of brain structure without radiation?

Answer: MRI

Magnetic Resonance Imaging (MRI) uses magnetic fields and radio waves to generate high-resolution structural brain images.

Heritability estimates from twin studies indicate the proportion of variance in a trait that is due to:

Answer: Genetic factors in a given population

Heritability is a population-level statistic estimating how much of trait variance within that population is attributable to genetic differences.

Which neurotransmitter is the primary inhibitory transmitter in the adult brain?

Answer: GABA

Gamma-aminobutyric acid (GABA) hyperpolarizes neurons by opening Cl- channels, making it the main inhibitory neurotransmitter.

The corpus callosum primarily connects which brain regions?

Answer: Left and right cerebral hemispheres

The corpus callosum is a massive white matter tract allowing communication between the left and right hemispheres.

Which stress hormone, released by the adrenal cortex, is elevated during chronic stress?

Answer: Cortisol

Cortisol is a glucocorticoid released by the adrenal cortex in response to ACTH, and chronically elevated levels impair immune function and memory.

Lesions to the hippocampus most severely impair which type of memory?

Answer: New declarative memory formation

The hippocampus is essential for encoding new explicit (declarative) memories; patient H.M. demonstrated this after bilateral hippocampal removal.

What is the term for the minimum level of stimulation required to trigger a neural action potential?

Answer: Action potential threshold

The action potential threshold is approximately -55 mV; if depolarization reaches this level, an all-or-none action potential fires.