TRACE (psycholinguistics)

TRACE was created during the formative period of connectionism, and was included as a chapter in Parallel Distributed Processing: Explorations in the Microstructures of Cognition.

[3] The researchers found that certain problems regarding speech perception could be conceptualized in terms of a connectionist interactive activation model.

The problems were that Each of these causes the speech signal to be complex and often ambiguous, making it difficult for the human mind/brain to decide what words it is really hearing.

"TRACE was the first model that instantiated the activation of multiple word candidates that match any part of the speech input.

Then, soon after, only bald and ball remain in competition (bad, bill have been eliminated because the vowel sound doesn't match the input).

If simulations are being compared to reaction time data from a perceptual experiment (e.g. lexical decision), then typically an activation threshold is used.

TRACE’s relevance to the modularity debate has recently been brought to the fore by Norris, Cutler and McQueen’s (2001) report on the Merge (?)

While TRACE permits word units to feedback activation to the phoneme level, Merge restricts its processing to feed-forward connections.

Merge advocates for modularity by arguing that the same class of perceptual phenomena that is accounted for in TRACE can be explained in a connectionist architecture that does not include feedback connections.

For example, it has been suggested that language deficits in expressive aphasia may be caused by excessive competition between lexical units, thus preventing any word from becoming sufficiently activated.

[9] Arguments for this hypothesis consider that mental dysfunction can be explained by slight perturbation of the network model's processing.

This emerging line of research incorporates a wide range of theories and models, and TRACE represents just one piece of a growing puzzle.