Dynamics of the semantic priming shift: behavioral experiments and cortical network model

Abstract

Multiple semantic priming processes between several related and/or unrelated words are at work during the processing of sequences of words. Multiple priming generates rich dynamics of effects depending on the relationship between the target word and the first and/or second prime previously presented. The experimental literature suggests that during the on-line processing of the primes, the activation can shift from associates to the first prime to associates to the second prime. Though the semantic priming shift is central to the on-line and rapid updating of word meanings in the working memory, its precise dynamics are still poorly understood and it is still a challenge to model how it functions in the cerebral cortex. Four multiple priming experiments are proposed that crossmanipulate delays and association strength between the primes and the target. Results show for the first time that association strength determines complex dynamics of the semantic priming shift, ranging from an absence of a shift to a complete shift. A cortical network model of spike frequency adaptive neuron populations is proposed to account for the non-continuous evolution of the priming shift over time. It allows linking the dynamics of the priming shift assessed at the behavioral level to the nonlinear dynamics of the firing rates of neurons populations.

Early dynamics of the semantic priming shift

“…Results show a main effect of relatedness, and deactivates previously activated associates to Prime 1 (similar to Lavigne et al, 2012, Experiment 2, using 200-ms PD2 and 50-ms ISI2).…”

“…As it is the case in the range of longer SOAs (Lavigne et al, 2012), UR priming is significant when SOA2 is equal or longer than SOA1…”

“…When of only the stronger associates to the Prime 1 (cf. Experiment 3) that would correspond to a "partial meaning" of the prime when the shift is on its way to the activation of all of the associates to the Prime 2 (see also Lavigne et al, 2012). A "single meaning" of the second prime only would rely on a full shift, such as the one that occurs at longer SOA2 (see Lavigne et al, 2012, Experiment 3).…”

“…At longer SOAs, the initially fast inhibition continues to build up, slowly, with the increased level and number of associates that become activated (Lavigne et al, 2011(Lavigne et al, , 2012.…”

“…A recent experimental study has revealed that the slow dynamics of the priming shift in the long SOA range depend on the strength of the association between the target and its related prime (Lavigne, Dumercy, Chanquoy, Mercier, & Vitu, 2012). An RU target strongly associated to its related Prime 1 becomes rapidly activated and stays activated longer after processing of the unrelated Prime 2.…”