Pinker Again

In my previous post Sapir-Whorf Revisited I cited Lakoff's theories on metaphor. A much simpler critique of Pinker can be made, based only on Pinker. He says

"...the famous Sapir-Whorf hypothesis of linguistic determinism, stating that people's thoughts are determined by the categories made available by their language, and its weaker version, linguistic relativity, stating that differences among languages cause differences in the thoughts of their speakers". (The Language Insinct, p. 57)

Now simply substitute "culture" for "language":

"...the Revised S-W hypothesis of cultural determinism, stating that people's thoughts are determined by the categories made available by their culture, and its weaker version, cultural relativity, stating that differences among cultures cause differences in the thoughts of their members."

Sound more reasonable? Most of Pinker's critique in his chapter on "Mentalese" would not apply.

Mentalese also appears to have numerous flaws. On a small scale, what is mentalese for our modern word 'telephone'? On a larger scale, for 'cell doctrine'? For 'plate techtonics'? For 'Standard Social Science Model'? For 'physical symbol system hypothesis / computational theory of mind'? All of these concepts are uniquely made available to us by our culture. They were not hard-wired by evolution. They provide categories which determine (or at least cause differences in) our thoughts.

I also doubt human cognition is based on Predicate Logic. We aren't very good at it, and systems actually based on it normally fall apart on the first inconsistency encountered in the real-world (see Carl Hewitt's heroic attempts to fix this in Common sense for concurrency and strong paraconsistency using unstratified inference and reflection).

Sapir-Whorf Revisited

The Sapir-Whorf Hypothesis asserts that categories in particular human languages influence or even control our possible thoughts. You have most likely heard this presented in its most (in)famous example, about Eskimos having N different works for "snow". I thought this version was well taken-apart by Steven Pinker in The Language Instinct. Recently an Edge essay HOW DOES OUR LANGUAGE SHAPE THE WAY WE THINK? by Lera Boroditsky has made me reconsider.

Using the terminology of Lakoff and Johnson's Philosophy in the Flesh, Pinker's critique is classic first-generation Cognitive Science. Pinker says the brain is the equivalent of a computer or Turing Machine, processing abstract symbols. He asserts that thinking is done in "mentalese", not in a particular human language. Translation to human language is the last step before speaking, so it cannot influence the core of thought.

Lakoff and Johnson's second-generation Cognitive Science can be difficult to grasp, so I'll go slow. It is a big idea, and since you can't see where I'm going, it is easy for me to get too far ahead for you to follow. Simply stated: thinking is largely based on metaphor, and abstract thinking is based on metaphorical analogy to bodily operations in the physical world. Re-read the examples in the first two sentences: "difficult to grasp", "go slow", "big ideas", "see where I'm going", "get too far ahead", "follow". All of these are related to operations or relations in the physical world. Their use in the realm of ideas is much more vague and abstract. It is easy to agree on a measurement for the "bigness" of a tree, but how do you measure bigness for an idea? Works such as Feldman's From Molecule to Metaphor show how evolution started with simple minds able to interact with the physical world, and placed increasing layers of abstraction on top. But abstract thinking still bottoms out at the use of modules originally evolved for physical world manipulation.

So how does this relate to language and Sapir-Whorf? The studies cited by Boroditsky indicate different cultures use different physical-world metaphors for their abstract thinking:

"English speakers tend to talk about time using horizontal spatial metaphors (e.g., "The best is ahead of us," "The worst is behind us"), whereas Mandarin speakers have a vertical metaphor for time (e.g., the next month is the "down month" and the last month is the "up month")."

This is plausible. There is no inherent reason why time should be metaphorically mapped horizontally versus vertically. It can easily be culturally determined rather than hard-wired into the brain. And this puts an interesting new spin on Sapir-Whorf. Thought is not determined by language, but instead both thought and language are determined by culturally transmitted, culturally specific abstract metaphorical mappings. And how is culture transmitted? Primarily through language. So linguistic determinism or linguistic relativity is in a sense correct, but not for the reasons usually proposed.

Brain Scans, Machine Learning, and Trillion-word Web Text Corpus

"The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a computational model that predicts the functional magnetic resonance imaging (fMRI) neural activation associated with words for which fMRI data are not yet available. This model is trained via a combination of data from a trillion-word text corpus, and observed fMRI data associated with viewing several dozen concrete nouns. Once trained, the model predicts fMRI activation for thousands of other concrete nouns in the text corpus, with highly significant accuracies over the 60 nouns for which we currently have fMRI data."

Predicting Human Brain Activity Associated with the Meanings of Nouns, Tom M. Mitchell, Svetlana V. Shinkareva, Andrew Carlson, Kai-Min Chang, Vicente L. Malave, Robert A. Mason, Marcel Adam Just, Science, 320, pp. 1191-1195, May 30, 2008.

This research is the most interesting I have seen on the mapping of internal brain structure based on analysis of large bodies of text available from the web. When generating machine-learned models from fMRI data, they found that for their tested set of concrete nouns the most accurate intermediate semantic features were sensory-motor verbs. This matches with others theories of ideas being represented as the convergence of many related sensory patterns. For instance, apple as the convergence of the word "apple", redness, shiny, apple taste, apple texture, picking-by-hand, etc.

Laser Sound

This project is based on the Make Controller I picked up at Maker Faire. It plays tones controlled by the interruption of laser beams. The laser beams are from Laser Levels, and the MacBook software is implemented in the Processing environment.

Details here.

CUDA GPGPU on MacBook Pro Laptop

I've ported my pthread generic and CUDA GPGPU real-time ray tracers to Mac OS X running on a MacBook Pro laptop. It has a 2.4GHz Intel Core 2 Duo processor and a NVIDIA GeForce 9600M GT graphics processor. The Performance for 1 and 2 software threads is comparable to my older Linux desktop, and the CUDA is within a factor of 3 of the desktop graphics card.

Threads    Frames Per Second
1           8.5
2          17.4
GPU        16.7

TxtView Application for Android

I've written a simple Android application for viewing .txt files from Project Gutenberg. It is still under development.

APK and source available here.

Three Key Concepts, and Their Application

• Occam's Razor
  "the explanation of any phenomenon should make as few assumptions as possible, eliminating those that make no difference in the observable predictions of the explanatory hypothesis or theory"
  


• Falsifiability
  "the logical possibility that an assertion can be shown false by an observation or a physical experiment"
  


• Uniformitarianism
  "the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present"
  

These three concepts form part of the bedrock of the Western scientific method. When taken seriously, they help refute most supernatural claims. Science asserts that physical law has been constant over the time frames of the evolution of life on Earth, the evolution of man, and the development of civilization.

While we cannot travel into the past to directly witness historical events, we can examine evidence that has been (or should have been) left behind. We can also closely examine contemporaries, in both our own and other cultures, making similar claims. In the case of current supernatural claims, not one has held up to scientific examination.

Psychology carefully avoids making judgments about the truth of supernatural claims, instead focusing the individuals ability to function within their local social group. In Western society today we still see individuals making supernatural claims very similar to those we read in ancient texts. Sometimes they are recognized as mentally ill, but this does not stop others from believing and following them. From this it is easy to assume ancient, pre-scientific peoples were even more credulous.

This leaves one with several options on how to partition one's world-view. One extreme is to assert that many contemporary supernatural claims, from many traditions, are all true. A more moderate position is that the world was different two to four thousand years ago, and that supernatural claims from that time period were true. Of course these positions are often subdivided where claims within one tradition are uniformly true while the others are false (or misguided interpretations of events actually powered by the one true source).

The simplest Occam's-Razor explanation is to take a Uniformitarian position and assert that all supernatural claims for all time are purely based in psychology.