Because the Triangle model has direct connections between orthography and meaning, in addition to semantically mediated connections, it is consistent with a weak phonological theory (Frost, 1998). The direct connections between orthography and phonology embody assembled phonology in a way that is sensitive to the distributional properties of the writing system. The semantically mediated connections are the equivalent of the addressed route, albeit different. The difference with DRC and CPD+ is that this route in the Triangle model always includes meaning. To explain the observation that patients with semantic dementia can name words with inconsistent grapheme‐phoneme correspondences, Woollams et al. (2016) argued that the semantic network is not completely lost, merely deficient. The combined activation through the direct orthography‐phonology connections and the deficient semantically mediated connections can still result in the correct naming of inconsistent words when the meaning is no longer fully understood (Woollams et al., this volume).
Phonology, Reading, and Neuroscientific Findings
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).
Conclusions
In this chapter, I have reviewed extensive evidence that phonology plays a central role in skilled reading. This is even the case in groups with suboptimal access to phonological forms within spoken language (such as people born deaf and students learning a second language in school), and notably, deficits in phonological processing are associated with reading problems (dyslexia).
Alphabetic languages use letters to represent the sounds of spoken words and this introduces two ways for deriving phonology. First, letters can be recoded into sounds, a process seen when readers name new or meaningless letter strings, such as teel. This has been called assembled phonology. Second, addressed phonology captures the observation that a visual word can be recognized as a familiar visual stimulus associated with a particular spoken name. This allows words such as awry or yacht to be named correctly, even though these words violate the most frequent letter‐sound correspondences. This type of addressed phonology also works in non‐alphabetic languages such as Chinese.
Figure 4.6 Brain regions involved in language processing, illustrating the dorsal pathway, connecting the phonology‐related brain areas, and the ventral pathway, connecting the meaning‐related brain areas. The pathways are bidirectional, combining bottom‐up and top‐down information streams.aFG = anterior fusiform gyrus, AG = angular gyrus, aSTG = anterior superior temporal gyrus, IFG = inferior frontal gyrus (also called Broca’s area), MFG = middle frontal gyrus, mSTG = middle superior temporal gyrus (includes the primary auditory cortex), PCA = precentral area, pFG = posterior fusiform gyrus, pSTG = posterior superior temporal gyrus (also called Wernicke’s area), SMG = supramarginal gyrus, SPL = superior parietal lobule.
For some time, researchers defended extreme positions about the contribution of phonology to visual word recognition: Either it was not involved at all, or phonological recoding was an essential step in visual word recognition. At present, it is widely accepted that orthographic and phonological information jointly contribute to visual word recognition and that this is achieved through rapid interactions between different forms of coding information in the brain. I discussed three computational models of how this can be realised (the DRC model, the CDP+ model, and the Triangle model). The hypothesis of two pathways in written word recognition with multiple interactions between orthographic, phonological and semantic codes also provides fruitful insights for the understanding of brain activity in visual word recognition (Figures 4.5 and 4.6).
In summary, it is clear from the evidence reviewed in this chapter, that visual language processing cannot be understood properly without taking phonology into account.
References
1 Adelman, J. S., Johnson, R. L., McCormick, S. F., McKague,