Questions 53 - 56 are based on the following passage.

    How are we able to find things in the dark? It is because our brain is able to store information in such a way that it can be retrieved by different senses. This multisensory integration allows us to form mental images of the world and underpins our conscious awareness.

    It turns out that the ability to recognise objects across different senses is present in the tiny brains of an insect. Researchers at Queen Mary University of London and Macquarie University in Sydney have published new work in the journal Science showing that bumblebees can also find objects in the dark they've only seen before.

    In the light, but barred from touching the objects, bumblebees were trained to find rewarding sugar water in one type of object (cubes or spheres) and bitter quinine solution in the other shape. When tested in the dark, bees preferred the object that was previously rewarding, spending more time exploring them.

    Dr Cwyn Solvi is the lead author on the paper who was based at Queen Mary University of London and is now at Macquarie University in Sydney. She said: "The results of our study show that bumblebees don't process their senses as separate channels-they come together as some sort of unified representation."

    Selene Gutierrez AI-Khudhairy, co-author on the paper, and now PhD student at the University of York, said: "This is an amazing feat when you consider the miniscule size of a bee's brain. future investigations of the neural circuitry underlying this ability in bees may one day help reveal how our own brains imagine the world as we do."

Source: https://www.sciencedaily.com. accessed November 15, 2019

54. The word "barred" in Paragraph 3 can be best replaced by ____