The Spatial and Temporal Signatures of Word Production Components: A Critical Update

Abstract

In the first decade of neurocognitive word production research the predominant approach was brain mapping, i.e., investigating the regional cerebral brain activation patterns correlated with word production tasks, such as picture naming and word generation. Indefrey and Levelt (2004) conducted a comprehensive meta-analysis of word production studies that used this approach and combined the resulting spatial information on neural correlates of component processes of word production with information on the time course of word production provided by behavioral and electromagnetic studies. In recent years, neurocognitive word production research has seen a major change toward a hypothesis-testing approach. This approach is characterized by the design of experimental variables modulating single component processes of word production and testing for predicted effects on spatial or temporal neurocognitive signatures of these components. This change was accompanied by the development of a broader spectrum of measurement and analysis techniques. The article reviews the findings of recent studies using the new approach. The time course assumptions of Indefrey and Levelt (2004) have largely been confirmed requiring only minor adaptations. Adaptations of the brain structure/function relationships proposed by Indefrey and Levelt (2004) include the precise role of subregions of the left inferior frontal gyrus as well as a probable, yet to date unclear role of the inferior parietal cortex in word production.

Distinct loci of lexical and semantic access deficits in aphasia: Evidence from voxel-based lesion-symptom mapping and diffusion tensor imaging

“…The left temporal lobe is thought to support both lexical and semantic level processing (e.g., Indefrey, 2011, Jefferies, 2013; see also Cloutman et al, 2009), and indeed, damage here is associated with exaggerated relatedness effects in language production (Schnur, Lee, Coslett, Schwartz, & Thompson-Schill, 2005) and M A N U S C R I P T…”

Electrophysiological evidence that inhibition supports lexical selection in picture naming

“…Our analyses revealed that the N2 was observed during the time window of 170-330 ms post picture onset. This corresponds to when lexical selection is likely to take place (i.e., 200-275 ms without scaling and 260-360 ms with scaling) according to Indefrey (2011); see also Costa et al (2009) and Indefrey and Levelt (2004). As can be seen, there was little difference in ERP responses to pictures with high and low NA in the earliest time window (0-170 ms, the time window of the P1, N1, and P2), but differences are seen starting from about 170 ms onwards.…”

“…The N2 effect peaked at about 290 ms after picture onset. In a meta-analysis of word production studies, Indefrey and Levelt (2004) and Indefrey (2011), see also Costa et al (2009), estimated that lexical selection takes place between about 200 to 275 ms after picture onset and phonological code retrieval between 275 and 355 ms. Based on these estimates, Cheng et al concluded that the observed N2 effect fell into the time window of phonological encoding. They assumed, however, that the primary origin of the effect emerged from competition between alternative lexical items which was not resolved before the onset of phonological encoding.…”

Dynamics of phonological–phonetic encoding in word production: Evidence from diverging ERPs between stroke patients and controls

“…Psycholinguistic experimental investigations coupled with neuroimaging studies allowing high temporal resolution (electroencephalography, EEG and magnetoencephalography, MEG) have modelled the mental operations involved in the planning of speech production (Levelt et al 1999;Dell, 1986) and their time course (Indefrey and Levelt, 2004;Indefrey, 2011). This field of research has largely been dominated by investigations of behavioural and neural responses in single word production since, on the one hand, words constitute the building blocks for sentence production, and, on the other hand, experimental and theoretical constraints have given priority to single word paradigms.…”

“…The dynamics of speech encoding processes have been intensively investigated with behavioral and electrophysiological techniques during single word production, leading to an estimate of the relative time course of the main underlying encoding processes (Indefrey and Levelt 2004;Indefrey, 2011). However, although the time course of lexical-semantic and lexical-phonological encoding during single word production has been directly investigated and confirmed by several event-related potential (ERP) studies, the estimate of phonological-phonetic encoding processes is based upon rather indirect evidence.…”