The effects of task irrelevant categories on the P3 component

Dora Isabel Lozano, University of Texas at El Paso


The effects of task irrelevant categories on the P3 component of event related potentials (ERPs) were examined in four studies. The “oddball paradigm” was used to elicit the P3 component in order to assess stimulus categorization along both task relevant and irrelevant dimensions. The first experiment examined whether the degree of deviation between a word and its context determines whether these deviations will affect the P3 when task irrelevant. The results showed that degree of deviation did not determine whether a task irrelevant category affected the P3 component, but that the categorizations performed in the first task were maintained in the second task. Experiments 2 through 4 examined this carry-over effect by varying the availability of categories in memory and by adding an intervening task between the first and second tasks. The results showed that pre-existing memory categories or prior experience with stimulus categories are not necessary for the carry-over effect, and that both newly formed and pre-existing categories are maintained through two tasks. Findings provide suggestive evidence that categorizations may become automatic because they are maintained when they are no longer part of the task. Finally, the current findings may have implications for the theories on the functional significance of the P3 component because these findings had not been reported before and should be incorporated into these theories.

Subject Area

Psychology|Experiments|Neurology|Molecular biology

Recommended Citation

Lozano, Dora Isabel, "The effects of task irrelevant categories on the P3 component" (2000). ETD Collection for University of Texas, El Paso. AAI9980094.