Relatedness proportion effects in semantic categorization: Reconsidering the automatic spreading activation process.

Abstract

Semantic priming effects at a short prime-target stimulus onset asynchrony are commonly explained in terms of an automatic spreading activation process. According to this view, the proportion of related trials should have no impact on the size of the semantic priming effect. Using a semantic categorization task ("Is this a living thing?"), we show that on the contrary, there is a robust effect of relatedness proportion on the size of the semantic priming effect. This effect is not due to the participants using the prime to predict the target category/response, as manipulating the proportion of category/response-congruent trials produces a very different pattern. Taken together with response time distribution analysis, we argue that the semantic priming effect observed here is best explained in terms of an evidence accumulation process and source confusion between the prime and target.

Evidence accumulation in the integrated and primed Stroop tasks

“…De Wit and Kinoshita (2014) analyzed the RT distribution of the semantic-priming effect in the semantic categorization task. Participants classified target words as denoting “animals” (living things including birds, insects, fish as well as mammals) or “nonanimals” (man-made objects).…”

“…In two different semantic categorization tasks (affective valence decision and person–object decision), Voss et al observed that category-congruent primes facilitated decisions relative to incongruent primes, and that the effect manifested as a distributional shift 4. In addition, de Wit and Kinoshita (2014) showed that increasing the proportion of semantically related trials magnified the size of the semantic-priming effect and that this increase was constant across the range of response latencies (affecting only the μ parameter); that is, it increased the amount of distributional shift. De Wit and Kinoshita (2015a) then showed that the distributional shift pattern of semantic-priming effects is also found when the primes are presented very briefly and (forward- and) backward-masked, so that the participants are unaware of its identity.…”

“…The interpretation offered by de Wit and Kinoshita (2014, 2015a, 2015b) of the distributional-shift pattern is that the semantically related, category-congruent prime provides a head start in the categorization process. In contrast to the tra-ditional “activation” view of semantic priming, in which the activation from the prime spreads and preactivates the target, priming effects here are explained in terms of an evidence accumulation process in which the information accumulated from the prime is combined with that accumulated from the target.…”

The onset and time course of semantic priming during rapid recognition of visual words.

“…This distributional shift has been interpreted to reflect a processing head start (Balota et al, 2008; Yap et al, 2013; for semantic categorization: De Wit & Kinoshita, 2014; 2015a) and as supporting the widely held belief that priming during visual word recognition is driven by the rapid prospective activation of related targets triggered by the prime. However, the current study shows that the observation, or lack thereof, of a distributional shift is strongly affected by the response time floor of the measure.…”

“…This head start mechanism would yield a semantic priming effect that is constant across the RT distribution. A pattern of semantic priming resulting solely from a distributional shift was also observed by De Wit and Kinoshita (2014; 2015a) for responses in a semantic categorization task. Similarly, the authors ascribe the distributional shift to a processing head start for related targets.…”