Automatic and controlled aspects of lexical associative processing in the two cerebral hemispheres

Abstract

Associative processing in the cerebral hemispheres was examined using ERPs and visual half-field (VF) methods. Associative strength was manipulated using asymmetrically associated pairs: viewed in one order (forward), there was a strong prime-to-target association, but in the backward order predictability was weak. N400 priming was greater for forward than backward pairs in both VFs and not different across VF, suggesting similar semantic representations and automatic meaning activation in the two hemispheres. However, a frontal P2 enhancement for forward pairs restricted to the LH suggests that it uses context to predict likely upcoming words. Also, greater late positive complex priming for backward pairs in the LH than the RH reveals a LH advantage for strategically reshaping meaning activation for weakly related and/or non-canonically ordered pairs. The results link asymmetries in word processing with those observed at the sentence level.

The language of arithmetic across the hemispheres: An event-related potential investigation

“…A few studies have looked at late positivities in each of the hemispheres. In one, there was greater late positive complex (LPC) priming for backward ordered word pairs in the left hemisphere (e.g., “meat” followed by “butcher”, where “meat” does not strongly prime “butcher”, but the words are clearly related) than in the right, which suggests that there is a left hemisphere advantage for strategically reshaping meaning activation for weakly related and/or non-canonically ordered word pairs (Kandhadai and Federmeier, 2010a). In a subsequent publication, it was observed that the right hemisphere could be forced to appreciate the relatedness in these types of word pairs (Kandhadai and Federmeier, 2010b), but, on the whole, in language contexts there seems to be a clear bias favoring the left hemisphere for sensitivity to semantic relatedness on late positive effects.…”

“…Indeed, over a decade of research has combined visual half-field presentation with event-related potentials (ERPs, a time-sensitive neural measure) to examine how the hemispheres differently apprehend words for meaning under different types of priming conditions (e.g., Kandhadai and Federmeier, 2010a,b; Dickson and Federmeier, 2014) and different types of sentential contexts (e.g., Federmeier and Kutas, 1999b; Wlotko and Federmeier, 2007). In the visual half-field technique, items of interest are presented to subjects lateralized to either visual field, which provides processing advantages to the contralateral hemisphere (i.e., items presented in the periphery of the left visual field will be preferentially apprehended by the right hemisphere, and vice versa for items in the right visual field.).…”

Hemispheric differences in the recruitment of semantic processing mechanisms

“…However, several recent findings have pointed to broad similarity in the hemispheres’ representation and initial activation of semantic information (Richards & Chiarello, 1995; Kandhadai & Federmeier, 2007, 2008, 2010). Such results bolster views that comprehension asymmetries may be driven, instead, by differences in how top-down mechanisms are used to shape initial semantic activation over time.…”

What forgetting tells us about remembering: The influence of top–down control on hemispheric asymmetries in verbal memory

“…Some evidence for PARLO comes from electrophysiology studies measuring event-related potentials (ERPs). In Kandhadai and Federmeier (2010a), amplitudes for the P2 ERP component were larger for prime-target pairs that shared a strong forward association (e.g., pillow-sleep) than for pairs that had weaker backwards associations (e.g., sleep-pillow). Importantly, this effect was larger when items were presented to the RVF-LH compared to when they were presented to the LVF-RH.…”