David’s Ramblings

(ELOG 5 for CS3790: Cognitive Science)

Memento is an interesting movie. I mean, yeah, it’s got the whole doing the entire story backwards thing. But it’s also got a character with anterograde amnesia [wikipedia]. Anterograde amnesia is something I first encountered while watching Memento. Whenever you hear about amnesia in movies, it always seems to be retrograde amnesia – the kind that always happens in soap operas – so I’d never really heard about anterograde amnesia. Apparently it’s more common though.

Anterograde amnesia largely occurs in one of two ways: drug-induced or trauma-induced. Drug induced amnesia can be overcome with time, but trauma-induced damage is typically permanent. Either way, the amnesia is caused by damage to the memory systems of the brain. While we are still unclear on how memory works in the brain, we do know the areas generally responsible for memory. The typical suspect in cases of anterograde amnesia is damage to the medial temporal lobe (MTL). The medial temporal lobe includes the hippocampus.

Memento features a character who is bashed over the head, causing damage to this area of his brain and destroying his ability to form new memories. The extreme extent to which he has this trouble may seem somewhat far-fetched, but if you’ve ever seen anything about Clive Wearing [youtube] then you can consider the main character of Memento as practically normal by comparison. The debilitating effect anterograde amnesia can have on a person is best exemplified in the movie when the main character is trying to remember a person as an enemy and finds himself struggling to find a pen to write this important fact down while he tries to keep the thought in short-term memory using rehearsal.

Anterograde amnesia often only involves what is know as declarative memory – memories of facts, such as what happened when. Often time the amnesiac retains the ability to form new habits or even simple skills and this is known as non-declarative memory. Also, in many cases, the person completely retains memories from before the cause of their illnesses. The contrast between these types of memory and how they are affected by anterograde amnesia definitely shows that the MTL is not the only place memory is dealt with in the brain. We see the main character in the movie using these differences to his advantage by using procedural habits to deal with his lack of memory.

Altogether, Memento is as intriguing a movie as anterograde amnesia is a condition. It’s definitely worth watching, even (or especially) if it was edited together to play out the story backwards. (Each colored scene in the movie happens chronologically before the scenes shown after it, and the black and white shots spliced in happen before all of the color events.) In fact, this style of story telling makes perfect sense from the point of view of the main character, whose life is not linear, but just a bunch of independent scenes.

(ELOG 4 for CS3790: Cognitive Science)

Last Tuesday we had a class discussing Autism and Autism Spectrum Disorders. But… I wasn’t there. In light of this, I decided to read up on Autism and watch the video shown in class.

(The video is: The Mind of a Visual Thinker [youtube])

Temple Grandin is a fascinating person. Her talk (see video above) on visual thinking was a great look into the thought process of someone one the Autistic Spectrum. Apparently she doesn’t think in words like many people, but instead thinks completely in visual pictures. When she hears the word steeple, she doesn’t just call to mind attributes of steeples, or even a generic steeple, but actual pictures of steeples she has seen at some point.

To Grandin, the major feature tying together the various parts of the Autistic Spectrum, is that all have a different way of thinking about things from those that are not in the Autistic Spectrum. She mentions three specific ways of thinking that many in the Autistic Spectrum find themselves in. One is thinking in pictures, which is the way Grandin herself thinks. Others may think in patterns or even in sounds, but the common theme is that these people think in one way more exclusively, rather than being able to easily switch and relate the different ways of thinking.

The physiological causes of Autism have not been found, but the current theory of how the behavioral differences develop follows this model:

The idea being that the genetic and possible environmental factors lead to a difference in the way the brain develops, which affects how the person is able to think, and finally results in an observable difference in behavior. Work is currently being done to develop a model that explains exactly how this process occurs in a way that fits current evidence. (A Cognitive Model of Autism [cc.gatech.edu])

In understanding Autism Spectrum Disorders, we do important work not only in helping those with Autism survive in a world of what Grandin refers to as neurotypicals. but also in understanding how the mind in general works.

(ELOG 3 for CS3790: Cognitive Science)

http://en.wikipedia.org/wiki/Gestalt_psychology

(All of my pictures are stolen from Wikipedia)

Gestalt psychology focuses on the idea that the whole is more than the sum of its parts. Gestalt psychology brings with it four main principles: emergence, invariance, multistability and reification. On top of that, there is also the application of gestalt to perception: prägnanz – our tendency to order our experience in a manner that is regular, orderly, simple and symmetric.

Emergence, the first principle given by gestalt theory, is demonstrated very well by above picture. The dog in the picture is not found by noticing a nose, then an ear, until we say, “a ha! That must be a dog because of all the features like a dog.” We notice the dog all at once. The dots organize themselves into that pattern almost magically.

Invariance is the second principle which states that our mind has a tendency to recognize objects regardless of scale, rotation and translation. Further, we can recognize objects despite warping and skewing, or differences in representation.

Third we look at multistability, our brain will waver between various interpretations of ambiguous experiences. Look at the figure below:

Finally, there’s reification – or generative perception. Our brain has a tendency to fill in the blanks to make a picture more understandable. In C below, our brain has a tendency to see a ball with spikes, not because a ball is drawn, but because the organization of spikes makes more sense in a 3d perspective of a globe.

The rules of prägnanz or the “Gestalt laws” of perception are all pretty simple. The law of common fate, the law of closure, the law of continuity, the law of symmetry, the law of similarity and the law of proximity, are all fairly self-explanatory. (See wikipedia if you need help). They have a real application for HCI purposes as well. If we know how people tend to group objects, we can apply these grouping to apply logical groupings for users.

Overall, the only real problem with Gestalt psychology is that is more a list of observations, and does almost nothing to explain how the brain works in this way. This has drawn a lot of criticism from other psychologists, seeing as it does nothing to extend our understanding. Still, knowing how people tend to group and classify objects is useful, especially when you’re going to be creating some sort of interface.

(ELOG 2 for CS3790: Cognitive Science)

There is a debate in cognitive science about whether the mind and the brain are the same. On the one side, the materialists – those who believe that the mind is simply a part of the brain, completely physical in nature. On the other side, dualists, those who believe that there is a distinct difference between the brain and the mind. The dualists feel that there is something beyond the brain.

Personally, I think I take the side of the dualists, though I do see a lot of merit in the claims of both sides. The materialists posit that everything can be understood in a very scientific manner. They claim that none of our brain actions are beyond scientific understanding. The fact that we can eventually understand everything, including the state of our brain, does appeal to my scientific nature. I like to think that we can eventually understand everything.

Unfortunately, the materialists claim that there is nothing beyond the brain to understand. They claim that we are really just very sophisticated machines with inputs and outputs predefined to certain specifications. To the materialist argument, consciousness is simply a by-product of randomly firing neurons that we could eventually learn to understand and even possibly control.

This leads to a very deterministic view on life in general, implying that if we had a good enough understanding of the person, we could entirely map out and predict every choice they would make. The materialists have to deny the possibility of free will. Everything is cause and effect – the brain is pushed by certain stimuli to create a certain response. As much as I like to believe that science holds all of the answers, I find it hard to swallow that I am a simple automaton carrying out tasks to some already defined specifications.

The dualist argument appeals to me because it does not try to deny free will. It proposes that there is something beyond our simple brain states. It claims that consciousness is not just simulated by random firing of neurons, but that there is something inherently different about the consciousness beyond simple brain states. The possibility of a brain affected by something beside external factors, a soul, if you will, gives me the benefit of having free will, of being in control of my own destiny.

When it comes down to it, the debate really is whether there is more to life than science can ever fully explain. I’m not very religious, but I can’t help but feel that there is.

(This is my Chapter 1 ELOG for CS3790: Cognitive Science )

Dual-coding Theory [wikipedia]

When we first talked about dual-coding theory in class, it intrigued me. I began to look at how I use my brain on a day to day basis and tried to see how well dual-coding applies to my own mental processes.

The basic idea is that we process mentally on two distinct channels – visual and verbal. When our brain must process information, the information comes generally in two forms – analog and digital. Analog information is basically that which is present in the physical world (buildings we see, faces, cars, etc). Digital information is that which is represented symbolically (words, feelings, math). Analog information tends to be better processed visually, while the digital information tends to work with the verbal side of things.

Often we can come up with a digital representation of an analog thought, but it loses a lot of the detail. Turning the time of a mechanical clock into the time 3:32 has the same general meaning, but we don’t know what color or size the clock was. At the same time, a symbolic, digital representation may require many images, or even be impossible to completely capture in an analog fashion.

A story was brought up in class of a woman who was unable to think of things in a digital way. All symbolic information had to be coded in her brain with analog mental pictures. She could not think of love just as an idea, but needed a picture to associate with love to understand it.

When I try to think about working with that sort of limitation, I find it hard to imagine I would be functional. My day-to-day mental process is almost completely based on speech. When I think, I talk silently to myself, phrasing the thoughts as if I am presenting them to an outsider. The purely symbolic nature of this internal dialogue is only occasionally interrupted by something concrete like visualization.

Working Memory [wikipedia]

As we currently understand the brain, memory is not a distinct mental process, but actually quite related to the processing of new experiences. For example, the same parts of the brain are shown to be active when shown a picture as when asked to recall a picture. This implies that the memory is actually a stimulus reconstructed on the fly, and processed in the same way we would process external stimuli.

The Dual-code hypothesis and Baddeley’s model of memory are then somewhat related. Considering my own experiences, they would seem to accurately describe my typical thought processes. Like I said, I usually think in words and not pictures, but the lack of pictures can be explained by the abundance of visual stimuli I am encountered with on a day to day basis. I imagine that my study would be helped by giving myself a chance to process more visual stimuli along with my “inner voice” explaining everything.