Event related potential (ERP) correlates of perceptual and functional categories: comparison between stimuli-matching by identity and equivalence

YORIO, ALBERTO; TABULLO, ÁNGEL; WAINSELBOIM, ALEJANDRO; BARTTFELD, PABLO; SEGURA, ENRIQUE

NEUROSCIENCE LETTERS

Elsevier

Año: 2008 p. 113 - 118

0304-3940

Event-related potentials (ERPs) correlates of two test criteria of an abstract category taskwere dissociated. In a stimulus equivalence task, 10 subjects observed pairs of figures presented serially in three conditions: reflexivity (generalized identity), equivalence (arbitrary derived relations from a previous training), and unrelated pairs. Theywere instructed to decide whether the second itemin a pair matched or mismatched the first one. Participants’ performance in reflexivity matching tests was faster and more accurate than in equivalence matching or mismatching responses. In the three conditions, an occipital P2, a frontalN2and a parietal P3 ERPcomponentwere elicited. The earliercomponents P2 andN2exhibited reflexivity matching effects, while the later component (P3) exhibited the only equivalence matching effect. In addition, the subtracted ERP components from unrelated minus identity and unrelated minus equivalence trials were computed within two time windows: 150–250ms (dN300) and 350–450ms (dN400). While both dN300 waveswere not significantly different, thecomparison of both dN400waves showed statistical differences. Correlates of partially perceptual (but contextually abstract) concepts are elicited earlier than those of pure abstract concepts. These ERPs correlates of stimulus equivalence relation tests of semantic categories are in concordance with the behavioral data.