OPTIONAL BACKGROUND READING (OVERVIEW):

Shelton, J. R., & Carmazza, A. (2001) The organization of semantic memory. In In B. Rapp (Ed.), The Handbook of Cognitive Neuropsychology: What Deficits Reveal About the Human Mind, Philadelphia: Psychology Press.

REQUIRED READING:

1. Caramazza, A. (1998). The interpretation of semantic category-specific deficits: What do they reveal about the organization of conceptual knowledge in the brain. Neurocase, 4, 265-272

2. Lambon-Ralph, M. A., Howard, D., Nightingale, G., & Ellis, A. W. (1998). Are living and non-living category-specific deficits causally linked to impaired perceptual or associative knowledge? Evidence from a category-specific double dissociation. Neurocase, 4, 311-338.

3. Shelton, J. R., Fouch, E., & Caramazza, A. (1998). The selective sparing of body part knowledge: A case study. Neurocase, 4, 339-351.

3. Moss. H. E., & Tyler, L. K. (2000). A progressive category-specific semantic deficit for non-living things. Neuropsychologia, 38(1), 60-82.

QUESTION FOR CRITICAL THINKING:
(just one this time)

1. Patient HW shows a deficit in semantic information for animals. His impairment was first noticed by co-workers at the San Diego Zoo, where he worked as a pretzel vendor. When he was told to set up his pretzel cart near the zebra compound, he instead put it up near the pony fields. After a peacock escaped, his co-worker, LF, asked if he had seen it and he said that it was right over there - but pointed to a chicken. With additional interrogation, it was discovered that he could not produce accurate descriptions or drawings of many animals if given the name (either visually or auditorily). Often these descriptions (or drawings) took the form of generic 4-legged animals and lacked defining features (e.g., the zebra's stripes). Imagine you are a neuropsychologist seeing this patient for the first time. Describe the predicted pattern of category deficits, include what other types of category or feature deficits (besides animals) this patient might exhibit (and how you would test for them), according to each of the following theories of conceptual organization in semantic memory. Please be sure to explain thoroughly why each of these theories would predict the pattern you describe (referring to data from the above articles).

• Domain-specific organization (i.e., evolutionarily salient domains)
• Modality-specific organization (i.e., sensory(perceptual)/function theory; SFT)
• Distributed models of organization (i.e., semantic feature space where semantic properties are organized together and are intercorrelated; contrast predictions of Devlin's model with those of Durrant-Peatfield)
• Organization is "Artefactual" (i.e., items are organized by non-semantic features such as familiarity or age of acquisition)

ADDITIONAL READINGS IF YOU WANT TO LEARN MORE ABOUT THE TOPIC:

1.  Crosson, B., Moberg, P. J., Boone, J. R., Rothi, L. J., & Raymer, A. (1997). Category-specific naming deficit for medical terms after dominant thalamic/capsular hemorrhage. Brain & Language, 60(3), 407-42.

2.  Bell, B.D., Davies, K. G., Hermann, & Walters, G. (2000). Confrontation naming after anterior temporal lobectomy is related to age of acquisition of the object names. Neuropsychologia, 38(1), 83-92.

3.  Kurbat, M. A., & Farah, M. J. (1998). Is the category-specific deficit for living things spurious? Journal of Cognitive Neuroscience, 10(3), 355-61.

4.  Caramazza A, Shelton JR (1998). Domain-specific knowledge systems in the brain the animate-inanimate distinction. Journal of Cognitive Neuroscience, 10(1), 1-34.

A full bibliography of all the papers on patients with category-specific deficits (up to 1998) can be found at: Neuroscase (1998). Vol. 4, pp. 399-427.