It’s a basic knitted muff using different yarn textures and colours. Items, such as beads, buttons and ribbons, are then attached (inside and outside) to provide even more tactile stimulation. People with dementia often have restless hands and can be soothed by having something to keep their hands occupied. The muff provides a source of visual, tactile and sensory stimulation at the same time as keeping hands snug and warm.
Crochet pattern is here. (Ravelry)
Sewn warmers are probably also useful, especially if made with stretchy materials.