What cognitive impairment might indicate fatigue on the last day of a four-day trip?

Spotty short-term memory can indeed be a significant indicator of cognitive impairment due to fatigue, especially after an extended period of work such as a four-day trip. As fatigue sets in, the brain's ability to function optimally decreases, leading to difficulties in retaining and recalling recent information—also known as short-term memory. This impairment may manifest as forgetting recent events or not being able to concentrate on tasks at hand.

On the other hand, options that suggest improved dexterity, clear decision-making, or vigilant alertness would not typically align with fatigue. Increased fatigue generally results in physical and mental sluggishness, reducing dexterity and making clear decision-making more challenging rather than improving it. Similarly, vigilance tends to wane under fatigue, as tiredness affects energy levels and focus, leading to lapses in awareness or attention. Thus, recognizing spotty short-term memory as an indicator of fatigue provides a crucial understanding of how cognitive functions can degrade under prolonged work conditions.