Hostname: page-component-7c8c6479df-94d59 Total loading time: 0 Render date: 2024-03-26T17:46:39.661Z Has data issue: false hasContentIssue false

Graphesthesia: A test of graphemic movement representations or tactile imagery?

Published online by Cambridge University Press:  02 October 2009

V. DRAGO*
Affiliation:
Department of Neurology, University of Florida, College of Medicine, Gainesville, Florida and Malcom Randall VA Medical Center, Gainesville, Florida Oasi Institute for Research, on Mental Retardation and Brain Aging, Troina, Enna, Italy
P.S. FOSTER
Affiliation:
Department of Neurology, University of Florida, College of Medicine, Gainesville, Florida and Malcom Randall VA Medical Center, Gainesville, Florida Department of Psychology, Middle Tennessee State University, Murfreesboro, Tennessee
D. EDWARD
Affiliation:
Department of Neurology, University of Florida, College of Medicine, Gainesville, Florida and Malcom Randall VA Medical Center, Gainesville, Florida
B. WARGOVICH
Affiliation:
Department of Neurology, University of Florida, College of Medicine, Gainesville, Florida and Malcom Randall VA Medical Center, Gainesville, Florida
K.M. HEILMAN
Affiliation:
Department of Neurology, University of Florida, College of Medicine, Gainesville, Florida and Malcom Randall VA Medical Center, Gainesville, Florida
*
*Correspondence and reprint requests to: Dr. Valeria Drago, University of Florida, Department of Neurology and Center for Neuropsychological Studies, McKnight Brain Institute at UF, 100 Newell Drive, Rm L3-100l, Gainesville, FL 32610-0236. E-mail: valeria.drago@neurology.ufl.edu

Abstract

Patients with corticobasal degeneration (CBG) often demonstrate agraphesthesia in the same hand they demonstrate apraxia. To recognize letters written in their hand subjects can develop a spatial representation and access graphemic representations. Alternatively, people can use movement working memory and match movement patterns to stored letter movement representations. To learn the method normally used without vision, normal subjects (12) had letters written on their palm either in the normal manner or in a reverse direction. If letters written on the hand are recognized by their spatial features (as when visually reading) direction should not influence letter recognition, but if letters written on the hand are recognized by movement patterns, then in the reverse condition recognition should be impaired. When letters were written normally there were no differences in error between the tactile and visual modality. When letters were written in reverse, however, normal subjects made more errors in the tactile than visual condition. Normally, people identify letters written on their hand by covertly copying (mirroring) the examiner and then access letter movement representations. This might explain why patients with CBG often have agraphesthesia associated with apraxia. (JINS, 2010, 16, 190–193.)

Type
Brief Communications
Copyright
Copyright © The International Neuropsychological Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Heilman, K.M., Coenen, A., & Kluger, B. (2008). Progressive asymmetric apraxic agraphia. Cognitive and Behavioral Neurology, 21, 1417.CrossRefGoogle ScholarPubMed
Lang, A.E., Riley, D.E., & Bergeron, C. (1994). Cortical-basal ganglionic degeneration. In Calne, D.B. (Ed.), eurodegenerative diseases (pp. 877894). Philadelphia, PA: W.B. Saunders.Google Scholar
Riley, D.E., Lang, A.E., Lewis, M.B., Resch, L., Ashby, P., Hornykiewicz, O., et al. (1990). Cortical-basal ganglionic degeneration. Neurology, 40, 12031212.CrossRefGoogle ScholarPubMed
Riley, D.E., & Lang, A.E. (2000). Clinical diagnostic criteria. In Litvan, I., Goetz, C.G., & Lang, A.E. (Eds.). Corticobasal degeneration (pp. 2934). Philadelphia, PA: Lippincott, Williams & Wilkins.Google Scholar