Impairment in decision making is a result of what part of the brain

prefrontal cortex

Explanation:

Impaired decision-making ability means that the individual is unable to comprehend all information that might be important to the decision, including maintain such information, even for a limited time, the implications, communicating the information and use of decision-making information.

Brain is responsible for all the decision making activities. The prefrontal cortex present in brain is often described as executive control and decision-maker. Damage to the prefrontal lobe of the brain is known to affect one's capacity for reasoning and making choices.

Hence, impairment in decision making is caused by damage to prefrontal cortex.