Gais and Born

Question 1

State the aim

Answer 1

To investigate whether the role of the neurotransmitter ACh in the human hippocampus while a person is in slow-wave sleep

Question 2

Explain the method

Answer 2

• Participants were 29 male participants between 18 and 35
• All participants completed two tasks between 10:00 and 10:30 pm - word memory task (declarative memory) and mirror image tracing (nondeclarative memory).
• Two experimental conditions, one group went two sleep, the other stayed awake
• On the first night they both received an infusion of physostigmine (stimulates ACh production)
• Sleep group received dose at sleep onset, wake control group received at 11:15PM
• Sleep group was woken three hours into sleep and asked to recall words from memory task and complete tracing task
• Control group stayed awake and completed the tasks again at the same time as the sleeping group
• On the second night, conditions were repeated but they all received a placebo

Question 3

Explain the results

Answer 3

During sleep, memory for declarative wordlist task distinctly decreased after physostigmine compared to placebo condition
In wake control elevation of acetylcholine did not result in decreased memory performance but insignificant increase in wordlist recall compared to placebo condition
Neither speed nor accuracy in non-declarative mirror tracing task decreased after physostigmine injection in either experimental or control conditions