Biomedical subjects
Peter Gordon
Publications and source records attributed to Peter Gordon.
Facts, events, and inflection: when language and memory dissociate.
We report on two brain-damaged patients who show contrasting patterns of deficits in memory and language functioning. One patient (AW) suffers from a lexical retrieval deficit and failed to produce many irregularly inflected words such as spun, forgotten, and mice, but demonstrated intact production of regularly inflected words such as walked and rats. She also had preserved declarative memory for facts and events. The other patient (VP) presented with a severe declarative memory deficit but showed no signs of impairment in producing either regular or irregular inflections. These patterns of deficits reveal that the retrieval of irregular inflections proceeds relatively autonomously with respect to declarative memory. We interpret these deficits with reference to three current theories of lexical structure: (a) Pinker's "words and rules" account, which assumes distinct mechanisms for processing regular and irregular inflections and proposes that lexical and semantic processing are subserved by distinct but interacting cognitive systems; (b) Ullman's "declarative/procedural" model, which assumes that mechanisms for the retrieval of irregular inflections are part of declarative memory; (c) Joanisse and Seidenberg's connectionist model, in which semantic information is critical for the retrieval of irregular inflections.
Numerical cognition without words: evidence from Amazonia.
Members of the Pirahã tribe use a "one-two-many" system of counting. I ask whether speakers of this innumerate language can appreciate larger numerosities without the benefit of words to encode them. This addresses the classic Whorfian question about whether language can determine thought. Results of numerical tasks with varying cognitive demands show that numerical cognition is clearly affected by the lack of a counting system in the language. Performance with quantities greater than three was remarkably poor, but showed a constant coefficient of variation, which is suggestive of an analog estimation process.
Gene expression profiling in the myelodysplastic syndromes using cDNA microarray technology.
The myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal disorders of the haematopoietic stem cell and primarily involve cells of the myeloid lineage. Using cDNA microarrays comprising 6000 human genes, we studied the gene expression profiles in the neutrophils of 21 MDS patients, seven of which had the 5q- syndrome, and two acute myeloid leukaemia (AML) patients when compared with the neutrophils from pooled healthy controls. Data analysis showed a high level of heterogeneity of gene expression between MDS patients, most probably reflecting the underlying karyotypic and genetic heterogeneity. Nevertheless, several genes were commonly up or down-regulated in MDS. The most up-regulated genes included RAB20, ARG1, ZNF183 and ACPL. The RAB20 gene is a member of the Ras gene superfamily and ARG1 promotes cellular proliferation. The most down-regulated genes include COX2, CD18, FOS and IL7R. COX2 is anti-apoptotic and promotes cell survival. Many genes were identified that are differentially expressed in the different MDS subtypes and AML. A subset of genes was able to discriminate patients with the 5q- syndrome from patients with refractory anaemia and a normal karyotype. The microarray expression results for several genes were confirmed by real-time quantitative polymerase chain reaction. The MDS-specific expression changes identified are likely to be biologically important in the pathophysiology of this disorder.