Interactions between visual and semantic processing during object recognition revealed by modulatory effects of age of acquisition Uzma Urooj a,f , Piers L. Cornelissen b , Michael I.G. Simpson f , Katherine L. Wheat c , Will Woods d , Laura Barca e , Andrew W. Ellis a,f, ⁎ a Department of Psychology, University of York, York, UK b Northumbria University, Newcastle, UK c Department of Cognitive Neuroscience, Maastricht University, The Netherlands d Brain and Psychological Sciences Research Centre, Swinburne University of Technology, Victoria, Australia e Institute for Cognitive Sciences and Technologies, National Research Council (CNR), Rome, Italy f York Neuroimaging Centre, University of York, York, UK abstract article info Article history: Accepted 25 October 2013 Available online 6 November 2013 Keywords: Object recognition Object naming Magnetoencephalography MEG Evoked Induced Beta band Semantics Age of acquisition The age of acquisition (AoA) of objects and their names is a powerful determinant of processing speed in adulthood, with early-acquired objects being recognized and named faster than late-acquired objects. Previous research using fMRI (Ellis et al., 2006. Traces of vocabulary acquisition in the brain: evidence from covert object naming. NeuroImage 33, 958–968) found that AoA modulated the strength of BOLD responses in both occipital and left an- terior temporal cortex during object naming. We used magnetoencephalography (MEG) to explore in more detail the nature of the influence of AoA on activity in those two regions. Covert object naming recruited a network within the left hemisphere that is familiar from previous research, including visual, left occipito-temporal, anterior tempo- ral and inferior frontal regions. Region of interest (ROI) analyses found that occipital cortex generated a rapid evoked response (~75–200 ms at 0–40 Hz) that peaked at 95 ms but was not modulated by AoA. That response was followed by a complex of later occipital responses that extended from ~300 to 850 ms and were stronger to early- than late-acquired items from ~325 to 675 ms at 10–20 Hz in the induced rather than the evoked compo- nent. Left anterior temporal cortex showed an evoked response that occurred significantly later than the first occip- ital response (~100–400 ms at 0–10 Hz with a peak at 191 ms) and was stronger to early- than late-acquired items from ~100 to 300 ms at 2–12 Hz. A later anterior temporal response from ~550 to 1050 ms at 5–20 Hz was not modulated by AoA. The results indicate that the initial analysis of object forms in visual cortex is not influenced by AoA. A fastforward sweep of activation from occipital and left anterior temporal cortex then results in stronger activation of semantic representations for early- than late-acquired objects. Top-down re-activation of occipital cor- tex by semantic representations is then greater for early than late acquired objects resulting in delayed modulation of the visual response. © 2013 Elsevier Inc. All rights reserved. Introduction Cognitive neuroscience has taught us a great deal about the neural basis of object naming and lexical processing. The broad structure of the underlying neural networks has been identified and accompanied by analyses of the functions of the different nodes in that network and their patterns of interconnectivity (see Cattinelli et al., 2013; DiCarlo et al., 2012; Martin, 2007; Price, 2012, for reviews). At the same time, a substantial body of work in cognitive psychology and psycholinguistics has shown that some objects and words are recognized and named con- sistently faster and with fewer errors than others, and has explored the contribution of factors such as age of acquisition, frequency, imageability and distinctiveness to generating those reliable differences (see Brysbaert and Cortese, 2011; Cortese and Schock, 2013; Davies et al., 2013; Juhasz, 2005). We know relatively little, however, about how such factors modulate neural processing. fMRI studies have helped to identify the brain regions whose activity levels are influenced by different properties of objects and words (e.g., Carreiras et al., 2006; de Zubicaray et al., 2012; Ellis et al., 2006; Graves et al., 2007; Zhuang et al., 2011), but exactly how and when those factors exert their influence remains poorly understood. The present study was concerned with identifying how and when object recognition and naming are affected by age of acquisition (AoA), one of the most powerful determinants of object and lexical processing speed in adults (Alario et al., 2005; Cuetos et al., 1999; Ellis and Morrison, 1998; Juhasz, 2005; Lagonaro and Perret, 2011; Monaghan and Ellis, 2010). The benefits of early learning in object and word recog- nition are consistent across both participants and languages, and are NeuroImage 87 (2014) 252–264 ⁎ Corresponding author at: Department of Psychology, University of York, York YO10 5DD, UK. Fax: +44 1904 323189. E-mail address: andy.ellis@york.ac.uk (A.W. Ellis). 1053-8119/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.neuroimage.2013.10.058 Contents lists available at ScienceDirect NeuroImage journal homepage: www.elsevier.com/locate/ynimg