Which of the following is an additional symptom that may develop with Parkinson's disease?

Memory impairment is a recognized symptom that may develop in individuals with Parkinson's disease. While Parkinson's is primarily known for its motor symptoms—such as tremors, stiffness, and bradykinesia—it can also lead to non-motor symptoms as the disease progresses. Cognitive changes, including memory issues, can occur due to the impact of Parkinson's on brain function and the connections between neurons. This cognitive decline may manifest as difficulties in attention, executive function, and memory, causing challenges in day-to-day activities and overall quality of life.

In contrast, other options do not align with the typical progression of Parkinson's disease. Weight gain is generally not associated with the condition, as many patients experience weight loss due to changes in metabolism and decreased activity levels. Vision improvement is also unlikely, as Parkinson's can lead to vision disturbances rather than enhancements. Enhanced taste is contradictory to the general findings, as individuals with Parkinson's often report changes in taste and smell. Thus, memory impairment stands out as a pertinent additional symptom relating to the overall understanding of Parkinson's disease and its multifaceted effects.