The medial occipital cortex of blind subjects is active during Braille reading (Sadato et al.,
1996). This activation occurs in early blind subjects (Cohen et al.,
1999; Sadato, Okada, Honda, & Yonekura,
2002), whereas the late blind and sighted deactivate these regions (Sadato et al.,
2002). Moreover, transcranial magnetic stimulation (TMS) over medial occipital cortex impaired the ability of early blind subjects to identify Braille or Roman characters (Cohen et al.,
1997), and infarction of bilateral occipital cortex caused alexia for Braille in an early blind person (Hamilton, Keenan, Catala, & Pascual-Leone,
2000), suggesting that visual cortex is functionally involved in Braille reading in the early blind. However, it remained unclear whether the visual cortical activity associated with Braille reading depends on sensory or cognitive (including language-related) processes, since the aforementioned imaging studies employed rest-state controls. In a study of Braille reading that controlled for linguistic processes using an auditory word control, only the late blind recruited activity in early visual cortex, whereas the early blind did not (Büchel, Price, Frackowiak, & Friston,
1998), suggesting that early visual cortical recruitment might actually arise from linguistic processing in the early blind. A number of subsequent studies lent strong support to this idea (Amedi, Floel, Knecht, Zohary & Cohen,
2004; Büchel, Price & Friston,
1998; Burton, Diamond & McDermott,
2003; Burton & McLaren,
2006; Burton, McLaren & Sinclair,
2006; Burton, Snyder, Conturo et al.,
2002; Burton, Snyder, Diamond, & Raichle,
2002; Röder, Stock, Bien, & Rösler,
2002).