Plasma cobalamin levels affect information processing speed in a longitudinal study of HIV-1 disease

G. Shor-Posner, R. Morgan, F. Wilkie, C. Eisdorfer, M. K. Baum

Research output: Contribution to journalArticle

16 Scopus citations


Objective: To determine whether information processing speed is influenced by change in plasma cobalamin status in human immunodeficiency virus type 1 disease. Design: A longitudinal study, using autoregression, to evaluate the relationship between plasma cobalamin status and change in information processing speed assessed by Posner Letter Matching, Sternberg Short-Term Memory Search, Figure Visual Scanning and Discrimination of Pictures, and continuous paired associates learning tasks. Setting: University of Miami (Fla) School of Medicine from fall 1987 through summer 1991. Participants: Eighty-four human immunodeficiency virus type 1-infected homosexual men aged 20 to 55 years. None of the subjects displayed acquired immunodeficiency syndrome-defining symptoms at baseline; over the course of the study, 9.5% progressed to acquired immunodeficiency syndrome. Main Outcome Measures: Biochemical measurement of plasma cobalamin; performance on information processing speed tasks. Results: Significant improvement in the Posner Letter Matching NI-PI (Name Identity minus Physical Identity) differential was associated with becoming cobalamin adequate or remaining adequate. Becoming cobalamin deficient, in contrast, was associated with a significant decline in the speed of accessing overlearned name codes. Conclusion: Normalization of plasma cobalamin inadequacy in human immunodeficiency virus type 1 disease may provide significant improvement in the speed of retrieving overlearned information from long-term memory.

Original languageEnglish
Pages (from-to)195-198
Number of pages4
JournalArchives of Neurology
Issue number2
StatePublished - Jan 1 1995
Externally publishedYes


ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Shor-Posner, G., Morgan, R., Wilkie, F., Eisdorfer, C., & Baum, M. K. (1995). Plasma cobalamin levels affect information processing speed in a longitudinal study of HIV-1 disease. Archives of Neurology, 52(2), 195-198.