Alcohol's Effects on Judgment, Coordination, and Memory

Acute Alcohol Impairment

• Judgment: Prefrontal cortex suppression → disinhibition, risk-taking, poor decision-making (DUI, unsafe sex, aggression).
• Coordination: Cerebellar & basal ganglia depression → ataxia, dysmetria, slowed reaction time → falls, crashes.
• Memory: Hippocampal disruption → anterograde amnesia (blackouts: fragmentary or en bloc); impaired encoding/consolidation.

Dose-Response

• 0.02–0.05% BAC: Mild relaxation, slight psychomotor decline.
• 0.06–0.10%: Clear impairment (legal driving limit 0.08% in most US states).
• 0.11–0.20%: Significant motor/cognitive deficits, mood lability.
• >0.20%: Severe intoxication; >0.30%: stupor, coma, respiratory depression risk.

Chronic Effects

• Persistent cognitive deficits (executive function, memory).
• Cerebellar atrophy → permanent ataxia.
• Wernicke-Korsakoff (thiamine deficiency).

Key Message

No safe level for driving or complex tasks. Impairment begins below legal limits.