Posts Tagged ‘Korsakoff patients’

The Influence of the Past on Our Attention in the Present

July 20, 2019

This post is based on a book by Stefan Van Der Stigchel titled “How Attention Works: Finding Your Way in a World Full of Distraction.” We have excellent memory for the context in which objects are located. It appears that we are good at remembering visual context because the information involved is of the unconscious kind, something for which we have an apparently unlimited memory. But repeating a certain visual context is of no benefit to people who have trouble picking up unconscious information, like learning a new motor skill. This includes patients with Parkinson’s disease who are unable to learn new unconscious motor skills as a result of problem with the basal ganglia. But, when unconscious memory is still intact, as it is in the case of patients with Korsakoff’s syndrome, experiments show that contextual cueing continues to function normally. As it is conscious memory that is affected in these patients, they will probably be unable to remember what they ate for breakfast, but will still be able to react more quickly to a repeated search from the day before.

Regardless of their lack of conscious memory, the fact that Korsakoff’s patients still possess a well-functioning unconscious memory for visual context means that it can be used to learn new tasks. However, it is important that the information is acquired in a completely errorless manner. Otherwise, the patients will also take the errors on board unconsciously resulting in the inability to distinguish between correct and an erroneous one. It is unfortunate when it is assumed that patients who have no conscious memory or are unable to learn new skills.

Recently it has been found that it is possible for these people to acquire new skills when they use “errorless learning.” A team of scientists led by Erik Oudman studied the errorless learning of a specific skill—how to operate a washing machine. This requires the ability to interact successfully with the external visual world by pushing the right button at the right time. Korsakoff patients who had never operated a washing machine before were able to do so after a few errorless learning sessions. They were not able to explain how they did it, because the required actions were not stored in their conscious memory.

Memories influence our choice of where to move our attention. Magicians take advantage of this. Magicians look away from the spot where a change is about to take place, click their fingers to distract our attention, and toward our expectation by allowing changes to occur where we least expect them. The fact that we know they are making fools of us makes it all the more impressive and in no way diminishes the effectiveness of their tricks. A trick only fails to work when we know exactly what to look out for. In that case we focus our attention on the right spot, which allows us to see the change (HM has never been able to do this). It is a myth that magicians’ tricks are all about speed and that objects disappear too fast for us to be able to notice. Although speed is important, we humans are unable to make something disappear so fast that other humans will not notice, provided they are paying attention. The trick lies in distracting our attention.

Dr. Stefan Van Der Stigchel writes, “It is fascinating to see tricks that have been around for hundreds of years still being used in modern scientific experimental studies. One such experiment involved studying the eye movements of an audience watching a magician perform a trick in which he makes a cigarette “disappear” by letting it fall under a table while concentrating his gaze on and clicking his fingers. The results were very similar to the results of attention blindness experiments. The test subjects who failed to see the cigarette disappearing had seen the change with their own eyes but had not paid any attention to it.”

Another good example is the trick with the disappearing ball. The magician throws a ball into the air a couple of times and it just seems to vanish suddenly in midthrow. On the final throw the magician makes it appear as if he has thrown the ball when in actual fact he still as it in his hand. He follows the expected path of the ball with his head and eyes. The audience thinks he has thrown the ball and that it just vanishes into thin air. It is obvious that the audiences’ eyes are looking at the right spot, but that their attention has moved to the expected location of the ball on the basis of the direction of the throw and where the magician is looking.