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  1. Study Categories Stimuli Task 1. Mummery et al (1996) A, T Spoken words Category fluency 2. Mummery et al (1998) A, T Written words Semantic & syllable decisions 3. Moore & Price (1999) A, F, T, V Pictures Naming 4. Moore & Price (1999) A, F, T, V Written words Matching and pictures 5. Gorno-Tempini (2000) Fa, A, T Pictures Naming 6. Phillips et al (submitted) F, T Written words Semantic & screen and pictures size decisions AIP 7b F5 STS Abbreviations: A=animals, F=fruit, Fa=famous faces, T=tools, V=vehicles. L 4 3 2 1 0 -1 W B B W B W P P Relating imaging and patient studies of tool processing J. Devlin1,2, C. Moore1, C. Mummery1, J. Phillips1, M. Gorno-Tempini1, M. Rushworth1,2, and C. Price1 1Wellcome Department of Cognitive Neurology, Institute of Neurology 2Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford Results (cont.) Summary of results Background • First study to demonstrate LPMT activation for tools relative to living things at a corrected level of significance. May be due to: • Small effect sizes (<3% rCBF) and • Context-specific effects, i.e. category effects were only present in tasks required semantic processing • Results consistent with previous imaging studies showing Tools > Animals in ventral pre-motor cortex BUT also demonstrated that this effect was not present relative to fruit • No area was activated only by tools Several functional neuroimaging studies have reported a region in the left posterior middle temporal cortex that is more active when words and pictures represent tools than other categories of objects (see Fig. 1 and ref. 14 for a review). This area is not damaged, however, by fronto-parietal lesions typically associated with selective deficits for man-made items4. The lesion data is more consistent with the few imaging studies that have reported increased left pre-motor activation for tools2, 7, 9. Figure 3: Effect sizes for tools 1. L. post. Middle temproal gyrus 3. L. anterior supramarginal gyrus 4 3 2 1 0 -1 %rCBF change W B B W B W P P 1 2 3 4 5 6 7 8 Figure 1: Tools activate LPMT 1 2 3 4 5 6 7 8 2. L. ventral pre-motor area Contrasts 1. Syllable decisions12 2. Screen size decisions13 3. Semantic decisions13 4. Semantic decisions12 5. W-P matching10 6. Category fluency11 7. Naming pictures6 8. Naming pictures10 4 3 2 1 0 -1 Value = 0.001% %rCBF change Discussion W B B W B W P P • These findings correspond well with the neurophysiological literature showing that in monkeys neurons in the ventral pre-motor area F5 respond to visually presented graspable objects such as tools and fruit5, 8. • This region is part of a “visuo-action” network including pre-motor (F5), anterior intra-parietal (AIP/7b), and inferior bank of the superior temporal sulcus (STS) regions (see Fig. 4) 1 2 3 4 5 6 7 8 Activation in the left posterior middle temporal cortex (LPMT) and left pre-motor area in normals in a picture naming task from (Martin et al. 1996) Key Phonological tasks W Words Perceptual tasks P Pictures Semantic decision tasks B Both words and Word retrieval tasks pictures Current Study • Tasks without a strong semantic component (e.g. screen size decisions and syllable decisions) did not show a consistent advantage for tools • More semantic tasks, on the other hand, such as semantic decisions and picture naming, revealed small ( <3% rCBF changes) but consistent effects for tools > living things • The current study investigated tool-associated brain activations in an attempt to reconcile the apparent discrepancies between the imaging and lesion literature. • Data from 50 subjects performing 6 experiments were acquired on a single PET scanner (see Table) • Single multi-factorial analysis with three factors: 1) Category (natural vs. man-made) 2) Task 3) Stimulus type • Man-made items divided in tools and non-tools. Figure 4: Macaque “visuo-action” network Q: Were these activations truly category-specific? Key A Animals Fr Fruit BP Body parts T Tools Fa Famous Faces V Vehicles FF False fonts Adopted from Jeannerod et al. (1995) Table • The three regions identified in the current study may be homologues of this visuo-action network. • The same regions often activated in human imaging studies of grasping or hand movements1,3 • These results provide a plausible explanation for patients with semantic impairments to man-made items who typically have large left fronto-parietal lesions:  Although the LPMT is spared, the lesion can affect the inferior parietal and ventral pre-motor regions and the connections between them. 1. L. posterior middle temporal area? Word-picture matching10 Picture naming10 Picture naming6 Relative effect sizes A Fr V T FF Fa A T BP A Fr V T MN SN  Tools (T), simple non-objects (SN) and body parts (BP) all activated the LPMT. Results • Tools relative to living things activated three regions in the left hemisphere (see Fig. 2): 1. Posterior middle temporal cortex (LPMT) 2. Ventral pre-motor cortex 3. Anterior supramarginal gyrus but only for tasks with a strong semantic component (see Fig. 3) References 1. Binkofski et al. (1998). Human anterior intraparietal areas subserves prehension: a combined lesion and fMRI activation study. Neurology, 50, 1253-1259. 2. Chao, L. L., & Martin, A. (2000). Representation of manipulable man-made objects in the dorsal stream. NeuroImage, 12, 478-484. 3. Ehrsson et al. (2000) Cortical activity in precision- versus power-grip tasks: An fMRI study. J. Neurophysiology, 83, 528-536. 4. Gainotti, G. (2000). What the locus of brain lesion tells us about the nature of the cognitive deficit underlying category-specific disorders: a review. Cortex, 36, 539-559. 5. Gallese, V., & Goldman, A. (1998). Mirror neurons and the simulation theory of mind-reading. Trends in Cognitive Science, 2(12), 493-501. 6. Gorno-tempini, M. L., Cipolotti, L., & Price, C. J. (2000). Which level of object processing generates category specific differences in brain activation? Proceedings of the Royal Society, London B, 1253-1258. 7. Grabowski, T. J., Damasio, H., & Damasio, A. R. (1998). Premotor and prefrontal correlates of category-related lexical retrieval. NeuroImage, 7, 232-243. 8. Jeannerod, M., Arbib, M. A., Rizzolatti, G., & Sakata, H. (1995). Grasping objects: the cortical mechanisms of visuomotor transformation. Trends in Neuroscience, 18(7), 314-320. 9. Martin, A., Wiggs, C., Ungerleider, L., & Haxby, J. (1996). Neural correlates of category-specific knowledge. Nature, 379, 649-652. 10. Moore, C. J., & Price, C. J. (1999). A functional neuroimaging study of the variables that generate category specific object processing differences. Brain, 122, 943-962. 11. Mummery, C. J., Patterson, K., Hodges, J., & Wise, R. J. (1996). Generating 'tiger' as an animal name or a word beginning with T: Differences in brain activation. Proceedings of the Royal Society of London B Biological Sciences, 263, 989-995. 12. Mummery, C. J., Patterson, K., Hodges, J. R., & Price, C. J. (1998). Functional neuroanatomy of the semantic system: Divisible by what? Journal of Cognitive Neuroscience, 10(6), 766-777. 13. Phillips, J., Noppeney, U., Humphreys, G. W., & Price, C. J. (submitted). A positron emission tomography study of action and category. 14. Price, C. J. & Friston, K. J. (in press) What has neuroimaging contributed to category-specificity? In G. Humphreys & E. Forde (Eds.), Category specificity in mind and brain . Sussex, England: Psychology Press. 2. L. ventral pre-motor area? Word-picture matching10 Picture naming10 Key A Animals FF False fonts Fr Fruit T Tools V Vehicles Relative effect sizes A Fr V T FF A Fr V T Figure 2: Tools > Living thingsfor semantic tasks only  Fruit (Fr) and tools (T) both activate the ventral pre-motor region. 3. L. anterior supramarginal area? Word-picture matching10 Picture naming10 L R L R L R Key A Animals FF False fonts Fr Fruit T Tools V Vehicles Relative effect sizes L. posterior middle temporal cortex (-62, -58, 0) SPM{Z}=5.3 p<0.005 corrected L. ventral pre-motor (-42, 4, 18) SPM{Z}=3.6 p<0.001 uncorrected L. anterior supramarginal (-60, -24, 34) SPM{Z}=3.8 p<0.001 uncorrected A Fr V T FF A Fr V T  Tools (T) and false fonts (FF) activated the anterior supramarginal region.