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A further way to understand print‐phonology connections comes from neuroimaging (see Yeatman, this volume). Following a meta‐analysis of the relevant literature, Taylor et al. (2013) described two routes from print to sound. Visual word processing starts in an area on the border of the occipital and temporal lobes (named posterior fusiform and occipitotemporal cortex in Figure 4.5). This region extracts (abstract) letter information from the visual stimulus. From this area, the assembled phonology pathway goes upward to the parietal lobe (angular gyrus, inferior parietal cortex) and from there to the inferior frontal gyrus, which is involved in speech perception and speech production. This pathway is called the dorsal route. The pathway for addressed phonology goes forward into the temporal lobe. It includes brain regions that can be linked to an orthographic lexicon (anterior fusiform gyrus) and regions linked to extracting the meaning from words (anterior fusiform gyrus, middle temporal gyrus, and angular gyrus). This pathway is called the ventral route.

Figure 4.5 Brain areas involved in the activation of addressed and assembled phonology in reading

(Taylor et al., 2013 / With permission of American Psychological Association).

Figure 4.6 gives a wider summary of the brain regions involved in visual and auditory language processing. It makes a distinction between the area involved in orthographic processing (the posterior fusiform gyrus), the areas involved in phonological processing (the superior temporal gyrus, part of the angular gyrus, the supramarginal gyrus, the precentral area, part of the inferior prefrontal gyrus, and part of the insula), the areas involved in meaning (anterior fusiform gyrus, middle temporal gyrus, part of the angular gyrus, part of the inferior frontal gyrus, the middle frontal gyrus, and part of the insula), and an area involved in directing attention to the relevant information (superior parietal lobule). It also shows the involvement of noncerebral structures (basal ganglia, hippocampus, right hemisphere of the cerebellum) and the major white matter tracks between the cortical areas. All connections are bidirectional, going bottom‐up and top‐down.

Tan et al. (2005) compared brain activation during word naming in Chinese and alphabetic languages. In line with the fact that Chinese is a logographic language with less scope for assembled phonology, the authors reported different brain regions active in the dorsal route in Chinese word reading. In particular, the middle frontal gyrus seemed to be heavily involved. Further research will need to confirm these differences, especially as it is difficult to fully match stimuli and tasks across different languages (Liu et al., 2020; Zhao et al., 2017).

A further neuroscientific finding is that the reading system is largely lateralized to the hemisphere controlling speech production. For the majority of people this is the left hemisphere, although for some 10% of lefthanders it is the right hemisphere (Gerrits et al., 2019; van der Haegen et al., 2012). The likely reason for this organization is that the many interactions between orthography and phonology are hindered when the language centers are distributed over the two hemispheres of the brain (Cai et al., 2008).