Where were you on 9/11? Most of you have a distinct memory and could explain it to me in great detail. The problem is, you are probably wrong. On September 12, 2001 psychologists asked a group of people where they were on September 11th. They then went back and asked the same question to the same people but this time they got different results. The initial group seemed to be recalling false memories based on the stories from those around them and from the media. I’ve linked an article here that explains this is phenomena in greater detail. The reason I highlighted this example is to show that memory is not as concrete as it seems.This week, I watched Lecture 7 and 8 which focused on perception and memory. Professor Bloom stated that our visual system is based on assumptions. We live in a three dimensional world however, our retinas can only see in two. Our brain makes up the difference and fills in the gaps. For the most part, these assumptions work well. It makes sense that judgement on size correlates with judgement on distance. If we were to stand in a field and look at a tower, our idea of how far away that tower is, is influenced by how tall we think the tower is. If we think the tower is roughly fifty stories tall and we can barely see it then we think that we are far away from it. However, if we think that the tower is only ten stories tall then our brain makes it seem like we are closer to the tower. This is still a confusing concept for me so I am not sure if I did the best job explaining it. Basically, a lot of what we see is based on what we know. Our brain changes how we perceive the outside world depending on what we know about it. Our brains are pretty smart but sometimes they can be tricked as is the case with the Ponzo Illusion:
Since the black lines are getting smaller, it makes the second yellow line look bigger when in fact, it is the same size as the first yellow line.
The Muller-Lyer Illusion works in a similar manner. The arrows on the second line point outward making the entire line look longer while the arrows point inward on the first line causing an opposite effect. I found the topic of perception interesting and may come back to it for my final project. I’m a big fan of Brain Games and am thinking about creating an illusion and seeing how many people fall for it.
Now, onto memory. This is a big topic so I’ll probably split it between this post and next week’s one. There are two types of things that we remember. Semantic which are facts such as Westtown is in West Chester, Pennsylvania. The other is episodic which is something that you have experienced like going on a ski-trip during winter break. Semantic memory stays the same but episodic memory can change as time goes on, as is the case with many of those who witnessed 9/11. I’ll be talking more about memory next week but I just wanted to give everyone a preview.