The Interactive Activation Model (jIAM)

Walter van Heuven > Research > jIAM

jIAM is an implementation of the Interactive Activation (IA) model of word perception (McClelland & Rumelhart, 1981; Rumelhart & McClelland, 1982) in Java.

Click here to start jIAM

Requirements: Java 1.4 or higher needs to be installed on your computer. You don't need to install Java on MacOS X because it is included in the OS, but for Windows you need to install Java (J2SE Runtime Environment). Firefox might need a java plugin. Java applet is tested with Safari and Firefox on MacOS X, and Explorer and Firefox on Windows.

How to run a simulation

First, you have to load a lexicon into the program. Click on the 'Get Lexicon' button to load an English lexicon. This lexicon contains 1323 English 4-letter words. Next, you have to enter a string of exactly 4 characters in the input field, then press the 'Run' button to start the simulation. A graph will be presented during the simulation with the activation values of all active nodes. You can highlite an activation curve of a node by selecting the node from a popup menu that appears when you right-click on the graph.

Special input characters

  • '_'     Underscore : Specifies a blank; Absence and presence (letter feature) units off
  • '.'     Period : Absence units on and presence units off
  • '*'     Asterisk : Letter feature units of letter K and R on (ambiguous R-K character)
  • '#'     Hash mark : Mask character; Features of the letters X and O are turned on

The IA model is described in detail in Chapter 7 of McClelland & Rumelhart (1988).

References

McClelland, J. L., & Rumelhart, D. E. (1981). An interactive activation model of context effects in letter perception, Part 1: An account of basic findings. Psychological Review, 88, 375-405.

McClelland, J. L., & Rumelhart, D. E. (1988). Explorations in the microstructure of cognition: A handbook of models, programs, and exercises. Cambridge, MA: MIT Press.

Rumelhart, D. E. & McClelland, J. L. (1982). An interactive activation model of context effects in letter perception: Part 2. The contextual enhancement effect and some test ans extensions of the model. Psychological Review, 89, 60-94.

 

Last updated: 3/11/08