Posts Tagged ‘basal ganglia’

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.

Self Awareness

February 25, 2019

This title of this post is the same as the title of a chapter in Daniel Goleman’s book “The Brain and Emotional Intelligence: New Insights.” There was a corporate lawyer who had a brain tumor. Fortunately, that tumor was diagnosed early and operated on successfully. But during the operation the surgeon had to cut circuits that connects key areas of the prefrontal cortex, the brain’s executive center, and the amygdala in the midbrain’s area for emotions.

After the surgery on every test of IQ memory and attention, the lawyer was as smart as he had been before the surgery. But he couldn’t do his job anymore. He lost his job and found that he couldn’t keep any job. He ended up living in his brother’s spare bedroom and, in desperation, he went to the neuroscientist Damasio to find out what was wrong.

The lawyer was fine on every neurological test. The clue to the problem became clear when Damaisio asked the lawyer, “When shall we have out next appointment?” Although the lawyer could provide rational pros and cons of every hour for the next two weeks, he could not decide which was best. Damaisio concluded that in order to make a good decision, we need to have feelings about our thoughts— and the lesion created during surgery meant he could no longer connect his thought with the emotional pros and cons.

These feelings come from the emotional centers in the midbrain, interacting with a specific area in the prefrontal cortex. When we have a thought its valences either positive or negative are evaluated by these brain centers. This helps us shuffle our thoughts into priorities, like when would be the best time for an appointment. Lacking that input, we don’t know what to feel about our thoughts, so we can’t make good decisions.

Our basal ganglia extracts decision rules as we go through every situation in life. Our accumulated life wisdom is stored in this primitive circuitry. However, when we face a decision, it’s our verbal cortex that generates our thoughts about it. But to more fully access our life experience on the matter at hand, we need to access further inputs from that subcortical circuitry. Although the basal ganglia have some direct connection to the verbal areas, it turns out also to have very rich connections to the gastrointestinal tract—the gut. So when making a decision, a gut sense of it being right or wrong is important information, also. It’s not that you should ignore the data, but if it doesn’t fit what you’re feeling, maybe you should think twice about it.

Coleman writes, “That rule-of-thumb seems to be at play in a study of highly successful California entrepreneurs who were asked how they made crucial business decisions. They all reported more or less, the same strategy. First, they were voracious consumers of any data or information that might bear on their decision, casting a wide net. But second, they all tested their rational decisions against their gut feeling—if a deal didn’t feel right they might not go ahead, even if it looked good on paper.”

The answer to the question,’Is what I’m about to do in keeping with my sense of purpose, meaning, or ethics?’ doesn’t come to us in words; it comes to us via this gut sense. Then we put it into words.”

Readers might remember that Trump says he thinks with his gut. However, unlike the entrepreneurs mentioned above, he is not a voracious consumer of data. In fact, he ignores data and depends on his gut. In this case what he gets from his gut is similar to what we find in our toilets.

A review of cortical and subcortical functions taken from Goleman follows:

The neocortex contains centers for cognition and other complex mental operations. The subcortex is where more basic mental processes occur. Just below the thinking brain, and projecting into the cortex, is the limbic center, the brain’s main areas for emotion. These areas are also found in the brains of other mammals. The more ancient parts of the subcortex extend down to the brainstem, known as the reptilian brain because we share this basic architecture with reptiles.