Speeded processing of grammar and tool knowledge in Tourette's syndrome

Neuropsychologia. 2007 Jun 18;45(11):2447-60. doi: 10.1016/j.neuropsychologia.2007.04.001. Epub 2007 Apr 5.

Abstract

Tourette's syndrome (TS) is a developmental disorder characterized by motor and verbal tics. The tics, which are fast and involuntary, result from frontal/basal-ganglia abnormalities that lead to unsuppressed behaviors. Language has not been carefully examined in TS. We tested the processing of two basic aspects of language: idiosyncratic and rule-governed linguistic knowledge. Evidence suggests that idiosyncratic knowledge (e.g., in irregular past tense formation; bring-brought) is stored in a mental lexicon that depends on the temporal-lobe-based declarative memory system that also underlies conceptual knowledge. In contrast, evidence suggests that rule-governed combination (e.g., in regular past tenses; walk+-ed) takes place in a mental grammar that relies on the frontal/basal-ganglia-based procedural memory system, which also underlies motor skills such as how to use a hammer. We found that TS children were significantly faster than typically developing control children in producing rule-governed past tenses (slip-slipped, plim-plimmed, bring-bringed) but not irregular and other unpredictable past tenses (bring-brought, splim-splam). They were also faster than controls in naming pictures of manipulated (hammer) but not non-manipulated (elephant) items. These data were not explained by a wide range of potentially confounding subject- and item-level factors. The results suggest that the processing of procedurally based knowledge, both of grammar and of manipulated objects, is particularly speeded in TS. The frontal/basal-ganglia abnormalities may thus lead not only to tics, but also to a wider range of rapid behaviors, including the cognitive processing of rule-governed forms in language and other types of procedural knowledge.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Female
  • Humans
  • Language Development*
  • Language Tests
  • Linguistics
  • Male
  • Reaction Time / physiology*
  • Recognition, Psychology / physiology*
  • Reference Values
  • Statistics, Nonparametric
  • Tourette Syndrome / physiopathology*
  • Verbal Learning / physiology*