VOL-6 Test 1 Passage 3 — IELTS Reading

Picture the following and prepare to be amazed. You’re walking across a college campus when a stranger asks you for directions. While you’re talking to him, two men pass between you carrying a wooden door. You feel a moment’s irritation, but you carry on describing the route. When you’ve finished, you’re told you’ve just taken part in a psychology experiment. ‘Did you notice anything after the two men passed with the door?’, the stranger asks. ‘No,’ you reply uneasily. He explains that the man who initially approached you walked off behind the door, leaving him in his place. The first man now rejoins you. Comparing them, you notice that they are of different height and build and are dressed very differently.

Picture the following and prepare to be amazed. You’re walking across a college campus when a stranger asks you for directions. While you’re talking to him, two men pass between you carrying a wooden door. You feel a moment’s irritation, but you carry on describing the route. When you’ve finished, you’re told you’ve just taken part in a psychology experiment. ‘Did you notice anything after the two men passed with the door?’, the stranger asks. ‘No,’ you reply uneasily. He explains that the man who initially approached you walked off behind the door, leaving him in his place. The first man now rejoins you. Comparing them, you notice that they are of different height and build and are dressed very differently.

Daniel Simons of Harvard University found that 50% of participants missed the substitution because of what is called ‘change blindness’. When considered with a large number of recent experimental results, this phenomenon suggests we ‘see’ far less than we think we do. Rather than logging every detail of the visual scene, says Simons, we are actually highly selective. Our impression of seeing everything is just that. In fact, we extract a few details and rely on memory, or even our imagination, for the rest.

Until recently, scientists believed that vision involved creating images within the brain. By forming detailed internal representations of our surroundings and comparing them over time, we could detect any alterations. However, in his book Consciousness Explained, philosopher Daniel Dennett argued that our brains only store a few key details about the world, which is why we can function effectively.

According to Dennett, creating elaborate images in short-term memory would consume valuable cognitive resources. Instead, we record what has changed and assume everything else remains unchanged. As a result, we inevitably overlook some details. Experiments had demonstrated that we tend to ignore elements in our visual field that seem unimportant, such as a repeated word or line in a text. But even Dennett didn’t fully realize just how little we actually ‘see’.

A year later, John Grimes from the University of Illinois drew attention by showing that people who were presented with computer-generated images of natural scenes failed to notice changes made while their eyes were, for example, scanning the scene or blinking. Dennett was pleased: ‘In hindsight, I wish I had been bolder, as the effects are more pronounced than I originally claimed.’

Subsequently, it was discovered that our eyes don’t even need to be moving to be deceived. A typical laboratory experiment might display an image on a computer screen, like a couple dining on a terrace. The image would briefly disappear, replaced by a blank screen, then reappear with a significant change, such as a raised railing behind the couple. Many people search the screen for up to a minute before spotting the alteration, and some never see it.