The computational modeling of sensitive periods

appear if the document is opened on a computer loaded with different fonts. The symbols are (upper case delta) and e (epsilon). These symbols appear on p. 3, paragraph 4, line 2 (below equation 1): "where a_{i is the activation of the sending unit and aj is the activation of the receiving unit, wij is the connection strength between them, [uppercase delta] is the change in this strength, and [epsilon] is the'learning rate parameter'(see, e. g., O'Reilly and Munakata, 2000, equation 4.2). "}