concepts C.4.a.(1). Literature review and background Studies in normal subjects have shown that concrete words, compared to abstract ones, have an earlier age of acquisition (Brown, 1957;Centner, 1982), are easier to learn and remember (Paivio, 1991), and are processed faster in lexical decision tasks (James, 1975;Kroll &Merves, 1986). This phenomenon, termed the """"""""concreteness effect,"""""""" has been addressed at length in several cognitively oriented theoretical accounts (Kieras, 1978;Paivio, 1971, 1991;Plaut &Shallice, 1993;Schwanenflugel, 1991). A strong effect of concreteness has also been demonstrated in many brain-damaged patients (see Saffran &Shod, 1999, for review). For example, aphasics show poorer comprehension and production of abstract words, compared to concrete ones (e.g., Crutch &Warrington, 2005;Franklin et al., 1995;Goodglass et al., 1969;Goodglass & 379 Project 5: Memory and Language DAMASIO, ANTONIO R. Wingfield, 1997;Marshall &Newcombe, 1966). This same pattern is typical of patients with deep dyslexia and deep dysphasia (e.g., Coltheart, 1980;Coltheartet al., 1980;Crutch, 2006;Franklin, 1989;Howard &Franklin, 1988;Martin, 1996;Morton &Patterson, 1980). Comparable results have been obtained in regard to high- imageable versus low-imageable words, where high-imageable words tend to have an advantage (e.g., Franklin et al., 1992;Marshall et al., 1996). Crutch and Warrington (2005) argued that abstract and concrete word meanings are based in representational systems that have qualitatively different properties. Given the potency of the concreteness effect, it is intriguing to find instances in which patients demonstrate the opposite pattern, namely, superiority in processing abstract words and concepts (e.g., Warrington, 1975;Warrington &Shallice, 1984). One of our patients defined duck as """"""""has fur, four legs, and is about 4 feet tall"""""""";for health, though, he said, """"""""the way you are feeling...you should have this to live a long time."""""""" Other cases of superiority for abstract concepts have been reported (Breedin et al., 1994;Carbonnet et al., 1997;Cipolotti &Warrington, 1995;Marshall et al., 1996;Sirigu et al., 1991;Srinivas et al., 1997). The available literature suggests that a relative superiority for concrete concepts is associated with damage to the perisylvian region of the left hemisphere, whereas superiority for abstract concepts is linked to bilateral damage to the anterior and inferior temporal lobes. This pattern has received some mixed support from functional imaging studies (Beauregard et al., 1997;Chertkow et al., 1998;Friederici et al., 2000;Noppeney & Price, 2004;Wise et al., 2000). It has been shown that simple imagery of the referents of concrete words (compared to abstract ones) activates structures in the left inferior temporal region (D'Esposito et al., 1997). Binder and colleagues (2005) found that abstract words, relative to concrete words, activated left inferior frontal regions;in general, concrete concepts triggered greater involvement of bilateral association areas, and abstract concepts triggered almost exclusively left hemisphere activation. Whatmough et al. (2004) found a difference between abstract and concrete concepts in the lateralization of fusiform activation (abstract-right; concrete-left);however, both types of concepts activated the left temporal cortex. Fiebach and Friederici (2004) found that abstract words activated a subregion of the left inferior frontal gyrus more strongly than concrete words, whereas
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