Simple objects and toys can help develop children's creativity, and so can well-designed toys. It depends on how children play with them and how much opportunity they're given to explore and discover using their imagination.
Younger children seem to need more realistic props rather than something as simple as a piece of wood to develop their creativity. Their fantasy is still developing, so they're too young to imagine a piece of wood as a bus or a doll. It's not until they're 4 or 5 that they can imagine things as other than they are.
Interestingly, children of all ages seem to like playing with the box and wrapping paper that gifts come in. The younger children explore and discover ways to use them by ripping or crumbling the paper and going in and out of the box. Older children, on the other hand, imagine what else the items can be, by drawing on the box and making it into a car, house or spaceship.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.