Handed out: Monday March 1, 1999, 11:10AM, Due: Thursday March 4, 1999, 9:00AM Turn in to Computer Science 182 box in Soda
Question 1 of 3: Triangle Nodes in tlearn
Use Tlearn to build and demonstrate a "triangle node" network as discussed in class. Recall that the network has three content nodes, plus some additional circuitry to yield the 2/3 property. If at least two of the content nodes are active, then after a few time steps, all three should become active. If one or fewer of the content nodes is active, then after a few time steps, none should be active. For concreteness, have an active be node positive and an inactive one be (near) zero or negative.
We suggest that you make all the nodes linear. Since the circuit involves feedback you should design it and used fixed connections. You should have three inputs, one or more output units, and have your three content units and triangle node between them. You may want to include weights from the bias unit to any of the content nodes or the triangle node as well. It doesn't matter what the "output units" do, we are interested in the content units.
To allow for Tlearn's initialization, your first data vector should be all zeros so a typical input will look like:
You will need parallel teaching data, but it will not be used. You will need to train the network before testing it, so set the number of sweeps to 1 in the training options menu, and set the learning rate and momentum to 0.
(1) Provide the .cf file for your network. (2) Demonstrate that your circuit works by turning in the "node activations" display for a few time steps and cases. (3) Discuss how robust this architecture is: how does it respond, for example, to:
Question 2 of 3: Spatial Relations Terms and Image Schemata
In this question, you will be functioning as a field linguist studying the difference in spatial relations terms between English and another language. If you are bilingual - a native speaker of a language other than English - you may choose to use yourself as a native consultant. You don't have to do this; you could instead study a language you do not speak natively, but which your consultant does. Be sure that your consultant is available to you for more than one session, in case you need to ask follow-up questions to test a hypothesis.
In either case, you are to find a native speaker of a language other than English to serve as your consultant. You will be given two copies of a chart, previously discussed in class, used in research by Melissa Bowerman and Eric Pedersen. The chart has 17 pictures on it. Each picture is numbered. On one copy, each picture has two English words next to it indicating a trajector (the first word) and a landmark (the second word) of a spatial relation. For example, picture 3 has the words "bugs/wall" next to it. You are to find out what spatial relations term is used in the language you are studying to characterize the relation between "bugs" and "wall" in the picture given. For example, in English, there is a preposition used: "on." In Finnish there is a suffix used: "-lla." In Dutch, there is a preposition: "op."
The first part of the assignment is to find out and (1) list what spatial relations terms are used for the trajector-landmark relations for each picture in the language you are studying. (2) Draw a line on the second, blank copy around all the pictures with the same terms and indicate which terms fit which encircled group of pictures.
You should be aware that spatial relations may reside in parts of speech other than prepositions, postpositions, and suffixes.They may be built into verbs, adverbs, nouns, etc. Moreover, a given spatial relation may be expressed by more than a single form, as in German where a preposition-case combination may be used.
The second part of the assignment is harder. (3) For each of the spatial relations terms you have found, propose a theory where what each terms means that will account for your data. For example, your theory might suggest that the meaning of a given term can be characterized by certain image schemas bound together in a specified way. (Example: "into" in English has the Goal of a Source-Path-Goal schema bound to the Interior of a Container schema and the Source bound to the Exterior.)
(4) For each image-schema, be sure to indicate (i) the image-structure; (ii) the semantic roles; (iii) the trajector and landmark; and (iv) what is profiled. If appropriate, also indicate any deictic centers. If you propose a force-dynamic schema, indicate agonist, antagonist, which force is greater, and any changes over time.
You might hypothesize that there is more than one polysemous sense for a given term. In that case, (5) you are to (i) characterize the meaning of each sense (perhaps giving an image-schema description) and (ii) propose how the senses are systematically related. If you believe that the senses form a radial category, propose a center and types of relations provided links to noncentral senses.
The most important part of any such fieldwork experience is getting enough crucial data to test your hypotheses. This may require going beyond the pictures on the sheet given. You may need to either find or draw other pictures, or to use commonplace typical situations. If so, (6) hand in any further pictures used (or common situations described), the results of your inquiry, and a discussion of what they show.
Please look over the BBS papers or abstracts and (1) tell us which you will select for analysis in your final paper and (2) (in a short paragraph) why (you wil not be required to write on the paper you select now -- you can always change your mind and select another one -- however, starting to look at the paper early is encouraged):
Arthur Glenberg. What Memory is For.: ftp://ftp.princeton.edu/pub/harnad/BBS/.WWW/bbs.glenberg.html
Barsalou, Lawrence W. Perceptual symbol systems ftp://ftp.princeton.edu/pub/harnad/BBS/.WWW/bbs.barsalou.html
Quartz, Steven R. & Sejnowski, Terrence J. The neural basis of cognitive development: A constructivist manifesto: ftp://ftp.princeton.edu/pub/harnad/BBS/.WWW/bbs.quartz.html