An Event-Related fMRI Investigation of Implicit Semantic Priming

Abstract

Abstract& The neural basis underlying implicit semantic priming was investigated using event-related fMRI. Prime-target pairs were presented auditorily for lexical decision (LD) on the target stimulus, which was either semantically related or unrelated to the prime, or was a nonword. A tone task was also administered as a control. Behaviorally, all participants demonstrated semantic priming in the LD task. fMRI results showed that for all three conditions of the LD task, activation was seen in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the inferior parietal lobe, with greater activation in the unrelated and nonword conditions than in the related condition. Direct comparisons of the related and unrelated conditions revealed foci in the left STG, left precentral gyrus, left and right MTGs, and right caudate, exhibiting significantly lower activation levels in the related condition. The reduced activity in the temporal lobe suggests that the perception of the prime word activates a lexicalsemantic network that shares common elements with the target word, and, thus, the target can be recognized with enhanced neural efficiency. The frontal lobe reductions most likely reflect the increased efficiency in monitoring the activation of lexical representations in the temporal lobe, making a decision, and planning the appropriate motor response. &

Functional neuroimaging of word priming in males with chronic schizophrenia

“…Many studies have found priming related decreases in the same regions as shown in our studies, however, some studies have shown semantic priming related increases in activity (e.g.. Rossell et al, 2003;Kotz et al, 2002). As was found in our study, the majority of semantic priming studies have found semantic priming related reductions in at least some portion of the middle temporal gyrus (Copeland et al, 2003;Giesbrecht et al, 2004;Rissman et al, 2003;Rossell et al, 2003;Kotz et al, 2002 andGold et al, 2006) and of the inferior frontal region (Copeland et al, 2003;Giesbrecht et al, 2004;Kotz et al, 2002;Matsumo et al, 2005;Wheatley et al, 2005). In fact, the one region that showed activity related to both long and short SOA priming in Gold et al, (a portion of the posterior middle temporal gyrus) was neuranatomically very close to the region showing correlations with thought disorder in the current study.…”

“…However, a number of other regions not found in the current study were also described to have shown priming effects in some studies. These include the superior temporal gyrus (Rissman et al, 2003;Kotz et al, 2002;Matsumo et al, 2005) and the posterior fusiform gyrus in studies using visual words (Wheatley et al, 2005;Gold et al, 2006). Schizophrenic subjects displayed less clear within-group activation reductions in response to word pair connectivity in left frontal and temporal regions.…”

Relationship between trait anxiety, prefrontal cortex, and attention bias to angry faces in children and adolescents

“…A Monte Carlo simulation (Rissman, Eliassen, & Blumstein, 2003;Monk et al, 2006) was used to control for multiple tests within the primary areas of interest. This method controls for type I errors, offering a reasonable correction for multiple tests during group level analyses in the regions of interest (ROIs).…”

Balanced bilinguals favor lexical processing in their opaque language and conversion system in their shallow language

“…not exclusive) engagement of each pathway would depend on the degree of the regularity, lexicality and/or familiarity of the word being read. Both routes have been proposed to rely on common structures, such as the left occipito-temporal region, which has been found to be activated in both phonological (non-lexical;Binder, Medler, Desai, Conant, & Liebenthal, 2005;Kronbichler et al, 2004;Mechelli et al, 2004;Xu et al, 2001) and lexical processing (Binder et al, 2005;Fiebach, Friederici, Muller, & von Cramon, 2002;Ischebeck et al, 2004;Rissman, Eliassen, & Blumstein, 2003). Regular and unfamiliar word or non-word reading may preferentially rely on phonological pathways, where each grapheme is sequentially mapped to its corresponding phoneme.…”

“…from orthographic and their corresponding phonological lexical entries. Lexico-sematic processing has most commonly been linked to bilateral inferiormiddle temporal (Ischebeck et al, 2004;Jobard et al, 2003) and inferior frontal regions/pars triangularis; BA 45; Fiebach et al, 2002;Jobard et al, 2003;Binder et al, 2005;Rissman et al, 2003;Ischebeck et al, 2004).…”