11.20.2015
Written By: Zoe Christenson Wick
Neuroscience Part 2!
This was my first time leading a lesson and it was a blast. It was the Friday before Thanksgiving vacation, so many of the students were already out of town so there were only 1 or 2 students per mentor. I think that ended up working really well for this type of lesson; giving each student a lot of one-on-one time and a lot of opportunities to ask questions and explore the experiment.
In the week between neuroscience lessons we compiled the students’ data from the prism goggle experiment and had them interpret the graph independently. At the beginning of this lesson we went through their interpretations and drew conclusions from the prism goggle experiment. This gave them experience interpreting graphs and performing data analysis as well as reinforcing the concept of brain plasticity. I gave a brief introduction of my very unplanned path to college and how I found neuroscience from my experience as a ballerina! The students seemed very interested in the idea of something unacademic leading to a career in something academic. After this we jumped into an introduction of somatosensation – the focus of this week’s lesson.
Somatosensation, or the sensation of touch, varies across your body. For instance, your ability to sense and discriminate touch on your fingertips is very different than your ability to sense and discriminate touch on your forearm. To demonstrate just how diverse this sensation is we used a two-point discrimination task in which the participant closes their eyes and simply has to say whether the experimenter touched them with 1 or 2 pin heads. The pin heads are varying distances from each other (~2mm, 5mm, 10mm, 20mm, 30mm, 40mm) and different parts of your body will have different threshold distances at which they will be able to identify that 2 pins touched them, rather than one. The students were very surprised by how “bad” certain parts of their body were at this task!
Not only did we experiment with distance between pins and various body parts, but we added a temperature component (using an ice pack or a heating pad to cool down or heat up a body part before repeating the task) and an optional pain component (the students pinching themselves) to see how that changed their performance on the task.
We also discussed brain plasticity within the area of the brain that receives somatosensory information and how certain people – people who play guitar or read braille for instance – will likely have perform better on this task on their fingertips than people who don’t.
One thing that we will need to do differently next time is add in more single pins because the students knew that there was only 1 single pin while there were 6 double pin options and some students started playing the odds wanting to boost their accuracy instead of honestly saying whether they perceived the touch of 1 pin or 2 pins.
In the end, I think a lot of the students got the message that their brain gives priority to somatosensory information from parts of their body that they need to use for fine touch and manipulation (like fingertips) over information from their forearms or elbows. The students were very surprised that the discrimination threshold distance was so high in certain areas.