Final answer:
Study 1 indicates that the assessment of alcohol use primarily involved the indicator of difficulty with memory function, due to the association of alcohol with reduced behavioral control and memory loss during excessive intake.
Step-by-step explanation:
The findings of Study 1 suggest that the assessment of alcohol use involved the indicator of difficulty with memory function. Alcohol is associated with decreases in reaction time, visual acuity, and lowered levels of alertness, alongside a reduction in behavioral control.
Excessive alcohol use can lead to a complete loss of consciousness and memories of events that occurred during intoxication.
Furthermore, chronic exposure to alcohol may result in withdrawal symptoms, including difficulty with impulse control, but this specific aspect seems secondary when considering the primary indicators mentioned.