Biological Bases of Behavior Flashcards

Which neurotransmitter is released at the neuromuscular junction to trigger muscle contraction?

Answer: Acetylcholine

Motor neurons release acetylcholine (ACh) at the neuromuscular junction, which binds nicotinic receptors to initiate muscle contraction.

Damage to the amygdala most consistently impairs which psychological function?

Answer: Fear conditioning and threat detection

The amygdala is critical for acquiring and expressing conditioned fear responses, as demonstrated by the famous case of patient S.M.

In split-brain research, if an image is presented only to the LEFT visual field, it is processed by which hemisphere?

Answer: Right hemisphere

The left visual field projects to the right hemisphere via the optic chiasm, where nasal fibers cross and temporal fibers stay ipsilateral.

Which structure in the midbrain contains dopamine-producing neurons whose degeneration causes Parkinson's disease?

Answer: Substantia nigra

The substantia nigra pars compacta houses dopaminergic neurons that project to the striatum; their loss causes the motor deficits of Parkinson's disease.

Long-term potentiation (LTP), a cellular model of memory formation, primarily involves which receptor?

Answer: NMDA glutamate receptor

NMDA receptors act as coincidence detectors; their activation during LTP allows calcium influx that strengthens synaptic connections.

The HPA axis stress response involves which sequence of hormone release?

Answer: CRH → ACTH → Cortisol

The hypothalamus releases CRH, which triggers ACTH release from the pituitary, which then stimulates cortisol release from the adrenal cortex.

Which method allows researchers to establish causal relationships between specific brain regions and behavior by temporarily disrupting neural activity?

Answer: Transcranial Magnetic Stimulation (TMS)

TMS uses magnetic pulses to temporarily disrupt cortical activity, creating virtual lesions that allow causal inference about brain-behavior relationships.