Semantic Context and Visual Feature Effects in Object Naming: An fMRI Study using Arterial Spin Labeling

Abstract

Abstract& Previous behavioral studies reported a robust effect of increased naming latencies when objects to be named were blocked within semantic category, compared to items blocked between category. This semantic context effect has been attributed to various mechanisms including inhibition or excitation of lexico-semantic representations and incremental learning of associations between semantic features and names, and is hypothesized to increase demands on verbal self-monitoring during speech production. Objects within categories also share many visual structural features, introducing a potential confound when interpreting the level at which the context effect might occur. Consistent with previous findings, we report a significant increase in response latencies when naming categorically related objects within blocks, an effect associated with increased perfusion fMRI signal bilaterally in the hippocampus and in the left middle to posterior superior temporal cortex. No perfusion changes were observed in the middle section of the left middle temporal cortex, a region associated with retrieval of lexical-semantic information in previous object naming studies. Although a manipulation of visual feature similarity did not influence naming latencies, we observed perfusion increases in the perirhinal cortex for naming objects with similar visual features that interacted with the semantic context in which objects were named. These results provide support for the view that the semantic context effect in object naming occurs due to an incremental learning mechanism, and involves increased demands on verbal self-monitoring. &

A perfusion fMRI investigation of thematic and categorical context effects in the spoken production of object names

“…An alternative explanation involves assuming the verbal cue allowed participants to generate a composite mental image from the objects. For example, Lloyd Jones and Vernon (2003) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Semantic context effects 30 comparable semantic interference effects in the PWI paradigm, suggesting common lexical-level selection mechanisms operate in both paradigms (e.g., de Zubicaray & McMahon, 2009;de Zubicaray et al, 2013;Piai et al, 2013). In addition, the hippocampal involvement is consistent with the operation of an incremental learning mechanism (e.g., Gluck et al, 2003;Meeter et al, 2005;Norman et al, 2007;Oppenheim et al, 2010).…”

“…In the Introduction (Section 1.1) to this paper, we noted that prior neuroimaging, lesion and tDCS studies had either not included presentation cycle as a factor in their analyses (e.g., Hocking et al, 2009;Janssen et al, 2011;Maess et al, 2002;Pisoni et al, 2012;Wirth et al, 2011) or partialed it out (e.g., Schnur et al, 2009), with LIFG involvement reported inconsistently across studies. We also noted this approach likely conflates two separate mechanisms proposed to operate in the first and subsequent cycles (e.g., Damian & Als, 2005;Navarrete et al, 2012).…”

“…Hence, the analysis involved non-independent data. The perfusion fMRI, magnetoencephalography (MEG) and electroencephalography (EEG) studies by Hocking et al (2009), Maess et al (2002 and Janssen et al (2011), respectively, all presented results for the interference effect averaged over cycles. Neither Hocking et al (2009) nor Maess et al (2002 observed differential activity in the LIFG, although both observed interference-related activity in the left posterior temporal cortex.…”

What do patients with epilepsy tell us about language dynamics? A review of fMRI studies

“…TLE is often accompanied by HS reflected in reduced hippocampal volume and an increased T2 MRI signal (Sisodiya et al, 1997). Although medial temporal regions such as hippocampus are mainly associated with memory functions (Scoville and Milner, 1957;Squire and ZolaMorgan, 1991;Lech and Suchan, 2013), a handful of neuroimaging studies have found increased hippocampal activity during language production (Pihlajamaki et al, 2000;Binder et al, 2008;Hocking et al, 2009;Whitney et al, 2009;Bonelli et al, 2011;Hamamé et al, 2014). Typically, lateralization of language and verbal memory are correlated .…”

The roles of conceptual feature overlap and distinctiveness during lexical access in spoken word production

“…However, several studies using perfusion fMRI, magnetoencephalography (MEG) and electroencephalography (EEG) have not reported involvement of the LIFG (Hocking, McMahon, & de Zubicaray, 2009;Janssen, Carreiras, & Barber, 2011;Maess, Friederici, Damian, Meyer, & Levelt, 2002). Those studies reporting LIFG involvement tended to average data over all cycles or include cycle as a covariate of no interest (de Zubicaray, Johnson, Howard, & McMahon, 2014).…”