If there’s a particle, there’s no banding in the future. If there’s banding, there wasn’t a particle in the past.
At any given point in the configuration space there is a particle, but since we’re not looking at it (and it’s not interacting with anything else) no decoherence occurs, and so we still get an interference pattern.
At any given point in the configuration space there is a particle, but since we’re not looking at it (and it’s not interacting with anything else) no decoherence occurs, and so we still get an interference pattern.