We examine the anatomic basis for abstract and concrete lexical representations in semantic memory by assessing patients with focal neurodegenerative disease. Prior evidence from healthy adult studies suggests that there may be an anatomical dissociation between abstract and concrete representations: abstract words more strongly activate the left inferior frontal gyrus relative to concrete words, while concrete words more strongly activate left anterior-inferior temporal regions. However, this double dissociation has not been directly examined. We test this dissociation in two patient groups with focal cortical atrophy in each of these regions, the behavioral variant of Frontotemporal Degeneration (bvFTD) and the semantic variant of Primary Progressive Aphasia (svPPA). We administered an associativity judgment task for abstract and concrete words, where subjects select which of two words is best associated with a given target word. Both bvFTD and svPPA patients were significantly impaired in their overall performance compared to controls. While controls treated concrete and abstract words equally, we found a category-specific double dissociation in patients’ judgments: bvFTD patients showed a concreteness effect (CE), with significantly worse performance for abstract compared to concrete words, while svPPA patients showed reversal of the CE, with significantly worse performance for concrete over abstract words. Regression analyses also revealed an anatomic double dissociation: The CE is associated with inferior frontal atrophy in bvFTD, while reversal of the CE is associated with left anterior-inferior temporal atrophy in svPPA. These results support a cognitive and anatomic model of semantic memory organization where abstract and concrete representations are supported by dissociable neuroanatomic substrates.

Observers falsely remember seeing beyond the bounds of a photograph (i.e., boundary extension [BE]). Do observers "zoom in" when viewing negative emotion photographs, resulting in boundary restriction (Safer, Christianson, Autry, & Österlund, 1998)? Studies have yielded inconsistent outcomes, perhaps because emotional valence was compared across photographs of completely different scenes. To control physical scene structure, two contrasting (negative vs. positive) emotional versions of the same scenes were created by dramatically changing individuals' facial expressions; 14 such scene pairs were selected based on participants' (n = 134) ratings of the emotional valence elicited. We attempted to enhance sensitivity to negative scene content by including participants who scored either high (n = 104) or low (n = 104) on trait rumination, which is characterized by repetitive analysis of negative mood and a narrowing of attention. They viewed either all negative or all positive emotion scenes (15 s each). These scenes were repeated at test and rated as "the same," "closer-up," or "farther away" than the stimulus view (on a 5-point scale). Participants in all groups exhibited BE, but neither emotional valence nor trait rumination affected performance, even though mood induction had occurred. Only physical scene context affected BE (irrespective of the emotional valence of the scenes). Results underscore the importance of controlling physical scene context in tests of the effect of emotion on spatial memory. The resilience of BE to negative-mood-inducing scenes is discussed in terms of the adaptive value of anticipating one's surroundings while navigating through scenes in the world. (PsycINFO Database Record