Sensory Adaptation

Sensory Adaptation

We have already covered the concept of priming in which exposure to a stimulus heightens the response to that stimulus. More exposure increases the response to that stimulus so, as in the example used in that article, when you are shopping for a specific model of car you are probably going to notice that car more often.

This effect is so profound that it can begin to feel that there are actually more VW Golfs or Nissan Altimas on the road than before (or more people talking about priming, or more websites about psychology, or whatever else you may stumble upon).

This can be useful for us because when something novel is introduced to us, it’s probably a good idea to keep an eye on it until we know what it is. If I’m a caveman just hanging out in my cave and I see a new animal around my sweet cave dwelling, it’s probably not a bad idea to be ever-aware of its presence until I figure out whether or not it’s a threat to me. So what happens when I determine it’s not a threat? What happens when the novel and the insignificant just becomes insignificant? Dedicating energy (physical or mental) to insignificant stimuli is a waste of our resources, so how do we handle that?

Sensory Adaptation

Initially we are more aware of a new stimuli but as time passes we become less aware. For example, you may remember the large furnaces that were in childhood schools. These absurdly loud things buzz and hum so loudly that when they turned off the teacher inevitably spent a few seconds yelling at us before adjusting to the change in noise level.

That’s not the interesting part though. The interesting thing about this example is that in spite of their loudness, they were inevitably tuned out while they were on. They were tuned out so effectively that their silence was temporarily more intruding than their loudness. What’s going on here? The answer is sensory adaptation.

In the most simple terms, as our brain determines that a stimulus is unimportant, or even distracting, it (more accurately, the central nervous system) simply begins to ignore it. This will cover the biology of this process in a later post but the chart above provides a nice visual.

Real World Example

Sensory adaptation happens every day and all around. It’s why your friends house stinks yet they don’t know what you’re talking about. It’s why you don’t smell the perfume you put on this morning by the time you get to class. It’s why the buzzing of the florescent light above you doesn’t seem to buzz, until I just pointed it out to you.

If you would like to find out more about sensory adaptation, please watch the following video:

Facial Recognition

Facial recognition
It is amazing the number of times we meet someone and we’re convinced that we’ve seen him or her before. Despite the fact that we encounter thousands of people in our lifetime, of the billions on this planet we seem to have the ability to remember a random face better than we remember the color of our first car. Facial recognition is a skill dependent on a specific part of our brain

This is a scene that has been played out weekly on TV crime shows; a witness can’t remember what a person was wearing but can spot a crook in a lineup with ease. The truth is that this isn’t merely the work of clever writers. It turns out, humans do have a special face recognition system.

What is the system?

It turns out that there is a specific area of the brain dedicated specifically to recognizing faces. It is an area of the brain that shows heightened activity when a person looks at a face. This activation does not occur when they look at anything else, like a mug or a car. It is known as the fusiform face area or FFA.

The FFA is located in the occipital lobe which is located at the rear of the brain. In most people, the FFA seems to be more prominent in the right hemisphere of the brain. The occipital lobe is where your brain processes what you see, so it makes sense that if there is an area specifically for processing faces that it is located here.

How do we know?

The FFA was first recognized in 1992 by Justine Sergent, Shinksuke Ohta and Brennan Macdonald of Montreal Neurological Institute.

What They Did

Sergent and his researches performed lesion studies on patients who had brain damage in the occipital and temporal lobes. Some of the subjects, it was already known, had problems identifying faces while other patients did not have this problem.

Subjects were presented with grated images, arbitrary objects, and faces. The goal for the subject was to identify what they were looking at as accurately as possible. Note: They were not asked to identify if what they were looking at was a face or an object, but rather identify what face and what object they were looking at.

While the subjects performed this task, a computer analyzed the levels of blood flow throughout the brain. This is a form of brain imaging known as PET. It works under the premise that when the brain works, it uses energy, and when the brain uses energy it needs to replace it. Energy is replaced through the blood. Thus, if a particular area of the brain is working harder, it is also getting more blood.

What they found

As suggested earlier, what they found was that there is a specific area of the brain that ‘lights up’ with activity when looking at a face in subjects who had no issues identifying faces. In subjects with brain damage in this same area, they had a significantly more difficult time identifying the faces.

Pretty simple huh? People who can identify faces have activity in a specific area of the brain, even people who may or may not have had brain damage in other areas of the brain. People who couldn’t identify faces though, also had brain damage in the same area of the brain that was highly active in those that could identify faces.

What to make of this?

For starters, these findings give indications that there are certain areas of the brain that are dedicated to specific tasks. This helps explain why some people may be better artists than mathematicians. Or why some excel at philosophy while others at English. But this is idea is not limited to academics. In fact, a recent study indicates that there is a percentage of the population that excels specifically at recognizing faces.

Psychology of Music Ability

Music abilityWhy is it that some of us are better at music than others? Is music ability genetically pre-determined? Well, it appears the answer to that question is yes!

Perhaps you know this family: The mother teaches piano, the daughter is the best singer in her high school chorus, and the son’s band won Battle Of The Bands last week.

It appears that this pattern isn’t random. A recent study out of Finland has found evidence that musical talent is a genetically inherited trait.

Who Are They?

Liisa T. Ukkola, Päivi Onkamo, Pirre Raijas, Kai Karma and Irma Järvelä of the University of Helsinki in Helsinki, Finland.

What They Did

Ukkola and her team found 343 Finnish individuals from 19 families who had professional or amateur musicians in their families. The individuals were tested on three separate standardized musical aptitude tests. The first tests the ability of an individual to recognize the structure of a musical piece. The second tests the ability for an individual to accurately recognize variations in pitch. The third tests an individuals ability to maintain consistent timing.

Together, these three tests comprise the basic aspects of a musical piece: structure, time and pitch. A fourth test of creativity required the individual to compose or improvise a piece of music. Their piece was then judged by many people through a web-based application.

What They Found

Ukkola and her team found that there was statistically significant correlations within family and how the individuals scored. More creative individuals tended to have more creative siblings.

Most importantly though, they found that music ability was directly related to a specific gene that is, ‘associated with social, emotional and behavioral traits, including pair bonding and parenting’. This provides a neurological basis for musical talent.

What This Means

These findings may seem logical on the surface but the implications are somewhat significant in explaining the psychology of music ability. It appears that many of the things that we are good at, in this case music, are directly related to our parents. This likely explains why there are so many Andretti men in racing or why any number of successful father son combination’s in sports exist.

The physical attributes given to us by our family is nothing new. Tall parents tend to breed tall children. Good-looking parents tend to breed good looking children. What makes this study interesting is that it seems feasible that many of the cognitive traits that we possess are also passed on from our family members biologically.

For years there has been a very intense debate about human intelligence and whether or not it is more the product of nature or nurture. The general consensus has been that there is an inherent genetic potential that must be nurtured to come to fruition. These findings do not exactly dismiss this notion, but they certainly confirm that many of our cognitive abilities are genetic in nature.

In short, there is a good chance that no matter how much you play guitar, you may never be as good as Hendrix. But then, Hendrix would never have gotten as good as he was had he never played, so I wouldn’t suggest not trying.