Neural regions essential for writing verbs

Functional imaging data collected during cognitive tasks show which brain regions are active during those tasks, but do not necessarily indicate which regions are essential for those tasks. Here, in a study of two cases of selectively impaired written naming of verbs after focal brain ischemia, we combined imaging and behavioral testing to unambiguously identify brain regions that are crucial for a specific cognitive process. We used magnetic resonance perfusion imaging to show that the selective impairment in each case was due to hypoperfusion (low blood flow) in left posterior inferior frontal gyrus (PIFG) and precentral gyrus (PrG); the impairment was immediately reversed when blood flow was restored to these regions, indicating that parts of the left frontal lobe are crucial for representing and processing verbs.

[1]  A. Caramazza,et al.  Representation of Grammatical Categories of Words in the Brain , 1995, Journal of Cognitive Neuroscience.

[2]  R. Berndt,et al.  Retrieval of nouns and verbs in agrammatism and anomia , 1990, Brain and Language.

[3]  Manjit,et al.  Neurology , 1912, NeuroImage.

[4]  G. Gainotti,et al.  Evidence for a possible neuroanatomical basis for lexical processing of nouns and verbs , 1994, Neuropsychologia.

[5]  A. Caramazza,et al.  On the Basis for the Agrammatic's Difficulty in Producing Main Verbs , 1984, Cortex.

[6]  A. N. Haendiges,et al.  Verb Retrieval in Aphasia. 1. Characterizing Single Word Impairments , 1997, Brain and Language.

[7]  H. Ellis.  stroke , 1997, The Lancet.

[8]  F. Buonanno,et al.  Pharmacological elevation of blood pressure in acute stroke. Clinical effects and safety. , 1997, Stroke.

[9]  A R Damasio,et al.  A Neural Basis for the Retrieval of Words for Actions , 2001, Cognitive neuropsychology.

[10]  A. Damasio,et al.  Nouns and verbs are retrieved with differently distributed neural systems. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[11]  Elizabeth K. Warrington,et al.  Category specificity in an agrammatic patient: The relative impairment of verb retrieval and comprehension , 1985, Neuropsychologia.

[12]  A. Hillis,et al.  Hypoperfusion of Wernicke's area predicts severity of semantic deficit in acute stroke , 2001, Annals of neurology.

[13]  A. Caramazza,et al.  Lexical organization of nouns and verbs in the brain , 1991, Nature.

[14]  S M Davis,et al.  Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI , 1998, Neurology.

[15]  Alfonso Caramazza,et al.  Modality-Specific Deterioration in Naming Verbs in Nonfluent Primary Progressive Aphasia , 2002, Journal of Cognitive Neuroscience.

[16]  J R Hodges,et al.  Selective impairment of verb processing associated with pathological changes in Brodmann areas 44 and 45 in the motor neurone disease-dementia-aphasia syndrome. , 2001, Brain : a journal of neurology.