Wednesday, March 23, 2011

Remembering David Rumelhart

“Language, like most knowledge, relies mainly on memory and is represented in the brain by a network of connected meaning.” ~ David Rumelhart [link]
While at the University of California, San Diego, David Rumelhart developed the ‘adaptive structural network’ model for both encoding and retrieving information in long-term memory. According to his model, information is stored in a database and retrieved by an active interpretive process. Storage is a process of construction from a sensory-base whereas retrieval is a process of re-construction from a conceptual base [link]. David’s contributions influenced my field of study; he informed the direction I took and the decisions I made. He will be missed.

Tuesday, March 22, 2011

Aphasia

Written in response to an article in the LATimes ~>[progressive aphasia]
No wonder we don’t know how to relieve aphasia, we still talk about it as though it were a speech problem. It’s actually a memory problem. What’s lost are the pathways that enable look-up and retrieval of words stored in memory. It only presents itself as a speech problem at early onset [link]. That’s why aphasia doesn’t lend itself to speech therapy. Treatments that focus on memory skills for word-retrieval are more helpful [link].
Symptoms: First, you have difficulty finding the right pronouns and names for things. They may escape the speaker entirely. Verb usage generally remains intact. “I can’t find the right world.” comes out instead of “I can’t find the right word.” “I’m going to the office.” in place of “I’m going to the store.” Homonyms or words that sound alike frequently get switched: “I’m going dental.” for “I’m going mental.” When I think of the all the steps that have to be performed in a fraction of a second and in the right sequence ..I’m surprised speech is possible at all. Even though speaking feels like a single, automatic process ..it’s by no means a  single skill. When you break it down, it looks something like this:

Idea ~>  Lexical    ~>     Context    ~>   Syntax     ~>     Speech
              Look-up &         Integation        Generation        Timing & Production
              Selection                                                                        

Tuesday, March 15, 2011

Psychology of facebook

Presented to the Santa Barbara Institute
for Consciousness Studies
Part two
Continued from [ part one ] below:   Now I want to talk about ‘discourse analysis’ and what it reveals about communication over social networks. Discourse analysis is the branch of psychology dealing the way people process information from what they hear and read. I think it’s telling. Face to face communication is a probabilistic event. Language is a relatively narrow band of communication that can only suggest what the speaker has in mind. This presents the listener with a range of possibilities. Communication is successful only when the listener infers the most likely meaning intended by the speaker. Ordinary conversation is generally successful because we have context to help guide us along. We rely on facial expressions, intonation, emphasis, location and other visual and auditory cues. However, where ordinary communication is probabilistic, text messaging is a crapshoot. Text is cryptic. Context is lost and we rely on memory to supply the missing cues. However, memory is fallible. Research in discourse processing has shown that the biggest piece of missing information we supply is the intention of the speaker ..and it’s their intention that we most often get wrong. We perceive threat where none was intended. Offense at what may have only been sarcasm. By nature, the flow of conscious experience is displaced over social networks. This simply means it occurs outside the context of our immediate situation. That’s the beauty of the Internet. It allows us to share experiences that are ‘displaced’ in time and space with users from all over the world. It also places a heavy burden on text comprehension, which is much less developed than speech comprehension in the language centers of the brain. I believe this will provide a rich source of field-observation for the study of human consciousness for years.

Monday, March 14, 2011

Psychology of facebook

Presented to the Santa Barbara Institute
for Consciousness Studies
Anthropology:   I’m going to start with what I know about anthropology, which isn’t much but I feel it’s relevant. In my view, facebook is a fairly tame and nontoxic community – unlike others I’ve been in (such as high school, workplaces, dinner tables, neighborhoods, yahoo chat rooms). Without a constitution or written protocol, congeniality prevails. I think this says something about human nature.  Social networks are tuned to the way we are wired.  Like taking the first step out of a cave and into a larger community where there’s no anonymity – it’s best not to offend anyone. Privacy is a recent development. Tribal villages are more typical of human existence. Just look at the indigenous people of the Amazon. They live in circular settlements with one wall surrounding the perimeter, but no walls on the inside. They’re never alone and everyone can see what everyone else is doing. It pays to be on-guard and congenial otherwise you risk offending others and being banished from the tribe. In the Amazon, that means certain death. I believe that’s where the fear of abandonment comes from. I’m not talking about some trendy catch-phrase from pop psychology. It’s built into our constitution because it was essential for our survival. The threat of death-by-banishment is no longer real but the feelings certainly are. So, on facebook ..we tread carefully.
Behavioral science:   Psychologists have known for a long time now that there are few things more rewarding in life than validation from our peers. It beats television and ice cream and it’s the motivation underlying most communication. That’s why Twitter is so widely popular. Without let-up, it provides a constant stream of validation for every thought that crosses our brain.
“Still your mind and you will not age as fast as people whose minds are constantly struggling to hold their personalities together.” 
This is a Buddhist recommendation aimed at countering a very active function of the human ego:  impression management.   We put a lot of effort into presenting the right ‘persona’ .. or the way we want others to see and remember us. There’s nothing spontaneous going on there. The messages we broadcast are anxiously crafted to make us look the way we want to be perceived. Don’t believe me ..? Look no further than politicians approaching an election year. Newt Gingrich recently found religion because it sends the right message to Christian conservatives. Mitt Romney has ‘reinvented’ himself to look stupid and appeal to the average voter. What people choose to share on facebook in no way presents the whole picture. It’s not our nature.

Thursday, March 03, 2011

Extraterrestrial adaptation

Robert Sapolsky
If an alien creature invaded earth by entering the brain of human beings, hijacking their nervous system and driving them to engage in high-risk ventures sure to lower their chances of survival .. you’d think some of us might notice something. Yet something disturbingly like this may be happening without notice. When mice get infected with toxoplasmosis, an alien bacterium, the toxoplasmum goes dormant inside the amygdala of their brain and reduces their fear of cats [link]. Cats eat the reckless mice and ingest the toxoplasmas where they wind up in the intestine mingling with others of their kind. Toxoplasmas reproduce sexually only in the gut of the cat, so suppressing the fear response in rats and mice is a sure way of gaining entrance into the cat intestine. Neuro-practitioners call this ‘adaptation by behavioral manipulation’ [link]. A parasite learns to manipulate host behaviors that enhance their own chances of survival. In other words, these alien bacteria learn to perform brain surgery in order to get rides to wild parties where they can exchange DNA and procreate!
Apparently these clever little creatures have found their way into people too. Nearly one third of all humans have dormant toxoplasmas sleeping inside their amygdala. Since people are pretty high up in the food chain ..the only real threat comes from themselves (or perhaps an unsuspecting bear or mountain lion). Chances are, infected individuals will start acting recklessly and wind up getting killed in a car accident involving excessive speed. So they only appear in the traffic section of the paper, or the actuarial tables of an insurance company. Otherwise, symptoms appear close enough to schizophrenia that they wind up in a psychiatric population and are never heard from again. I think I would call this a successful alien predation.