The Cross-Modal Priming Task (CMPT), developed by David Swinney, is an online measure used to detect activation of lexical and syntactic information during sentence comprehension.
Prior to Swinney's introduction of this methodology, studies of lexical access were largely procured by offline measures, such as a phoneme-monitoring task.
Since Swinney considered the system of resolving ambiguities to be an autonomous, fast, and mandatory process, he suggested that the “downstream” temporal delay between stimulus and response could contaminate results.
During this task, study participants heard recorded sentences containing lexical or syntactic ambiguities while seated in front of a computer screen.
Particularly, they were interested in how these different groups resolved non-canonical object-relative constructions that contained an ambiguous noun with a strong biasing context.
The Probe Positions 1, 2 and 3 indicated in the sentence above indicate the points at which the study participants were presented with a word on a computer screen, in a cross-modal decision task similar to the one described above.
Moreover, the Probes represented either one ("pencil") or another interpretation ("jail") of the noun "pen" or were non-related controls ("jacket" or "tale") or a non-word of equivalent length.
Researchers attributed this difference to the prior exposure of many in the non-NINES groups to languages that relied less explicitly on word order for comprehension.
In this experiment, Zurif, Swinney and Garret built upon existing research on language processing errors in Broca's and Wernicke's aphasia patients.
Here, the gap between the subject noun phrase and relative pronoun is necessarily resolved through mental reordering of the sentence's structural elements.
Study participants were then asked to respond as quickly as possible by pressing either a "yes" or "no" button depending on whether the stimulus on the computer screen was an actual word or not.
Findings indicated that, in support of the hypothesis, the capacity and resources available to patients with Wernicke's aphasia to procure appropriate gap filling remain intact.
The researchers argue, based on these results, that neurological damage to the left anterior cortex implicates this region in resolving gap-filling operations during sentence comprehension.