Puzzles and other interactive art mediums have been shown to have a number of cognitive and psychological benefits for individuals with dementia and memory-related decline. These activities are often used as therapeutic tools to help improve memory, attention, and problem-solving skills, and to reduce anxiety, depression, and agitation.

Research has shown that completing puzzles can help improve memory function in individuals with dementia. One study published in the International Journal of Geriatric Psychiatry found that elderly individuals with dementia who completed puzzles regularly showed significant improvement in memory function compared to those who did not.

Another study published in the Journal of the American Geriatrics Society found that older adults with dementia who participated in a program of interactive visual art therapy had a significant reduction in agitation and an improvement in mood compared to a control group who did not participate in the therapy.

Interactive art projects also have benefits for caregivers, by providing a focused and fun activity to do together and it can foster communication and emotional connection.

Interactive art and puzzles can also help to promote feelings of self-esteem and self-worth in individuals with dementia, by providing them with a sense of accomplishment and purpose. It may also help to promote social interaction and communication among participants.

It is worth noting that for people with advanced dementia, these activities may not have much effect, as their cognitive abilities have degenerated too much. But for people with mild to moderate dementia, these activities can have great benefits.

Overall, the research suggests that puzzles and other interactive art can be beneficial for individuals with dementia and memory-related decline. It is important to consult with the health care professional for the elderly person involved before starting any activities, as each individual's needs will vary.