[Event-related potentials of relational memory in target and delay phases of working memory].

Objective: To compare the spatiotemporal pattern of event-related potentials (ERPs) of relational memory retention between color-location binding and semantics-location binding.

Methods: The ERPs of 19 channels were recorded from 14 healthy subjects while performing the two binding delayed-match-to-sample tasks. A paired-sample t test was used for analysis of both the behavioral performance and ERPs, and statistical parametric mapping (SPM) of the t values was applied to ERPs.

Results: Behavioral performances (reaction time and accuracy) in color-location binding were significant better than those of semantics-location binding. The SPM(t) of the ERPs showed significant effects in the middle frontal region and most areas of the parietal lobe (about 200 ms), the bilateral prefrontal and frontal regions (260 approximately 320 ms), and the left occipital region (500 approximately 580 ms).

Conclusion: Retention of semantics-location relation involves more brain regions than that of color-location relation, and the largest effect occurs in the frontal region.