To learn about the model and how to run it, see this page from the lecture.
That is, where would the perceived beats of different strength underlying the pattern be? For example, for the repeating pattern (1 1 1 0), people would place accents on the first and third beats (the beginning and end of a run), one stronger than the other:
2 0 1 0 2 0 1 0 ...For the repeating pattern (1 0 1 0 1 1 1 1), people would place accents on every other beat, accenting every fourth beat more and every eighth beat even more, for example:
3 0 1 0 2 0 1 0 3 0 1 0 2 0 1 0 ...Note that there is often more than one possible meter assignment for a pattern?
Recall that patterns are difficult to assign meter to when there is a conflict between grouping and meter, that is, when the places that are accented because of how the events are grouped are not equally spaced. For example, the above patterns are relatively easy, but the pattern (1 1 0 1 1 0 1 0) is difficult because the grouping would lead one to accent things in this way:
1 0 0 1 0 0 1 0or
0 1 0 0 1 0 1 0But this leaves the distances between the accents unequal.
To assess the performance of the production system, you will need to look at the working memory after you run the system on the pattern. The last line of the "interpreted" working memory shows the strengths for each of the 24 time steps in the sequence. Remember that the pattern is repeated several times in the sequence. If you can, figure out a way to combine the information from the different repetitions of the pattern.
There are two ways in which we might expect to see greater difficulty for the network. First, it may take the network longer to find a suitable meter for a pattern. Second, it may not settle on one stable meter. Instead it may show different beat assignments over different places within the sequence of 24 time steps, or it may vary from one cycle of the program to the next. To look for evidence of both of these, you will need to compare the performance after 20, 40, 60, and 80 cycles for the different patterns.
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Last updated: 4 December 1995
Copyright 1995, The Trustees of Indiana University