Delay discounting and frontostriatal fiber tracts: A combined DTI and MTR study on impulsive choices in healthy young adults

Jiska S. Peper, René C.W. Mandl, Barbara R. Braams, Erik De Water, Annemieke C. Heijboer, P. Cédric M.P. Koolschijn, Eveline A. Crone

Research output: Contribution to journalArticleAcademicpeer-review

119 Citations (Scopus)

Abstract

Delay discounting, a measure of impulsive choice, has been associated with decreased control of the prefrontal cortex over striatum responses. The anatomical connectivity between both brain regions in delaying gratification remains unknown. Here, we investigate whether the quality of frontostriatal (FS) white matter tracts can predict individual differences in delay-discounting behavior. We use tract-based diffusion tensor imaging and magnetization transfer imaging to measure the microstructural properties of FS fiber tracts in 40 healthy young adults (from 18 to 25 years). We additionally explored whether internal sex hormone levels affect the integrity of FS tracts, based on the hypothesis that sex hormones modulate axonal density within prefrontal dopaminergic circuits. We calculated fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity, radial diffusivity (RD), and magnetization transfer ratio (MTR), a putative measure of myelination, for the FS tract. Results showed that lower integrity within the FS tract (higher MD and RD and lower FA), predicts faster discounting in both sexes. MTR was unrelated to delay-discounting performance. In addition, testosterone levels in males were associated with a lower integrity (higher RD) within the FS tract. Our study provides support for the hypothesis that enhanced structural integrity of white matter fiber bundles between prefrontal and striatal brain areas is associated with better impulse control.

Original languageEnglish
Pages (from-to)1695-1702
Number of pages8
JournalCerebral cortex
Volume23
Issue number7
Early online date12 Jun 2012
DOIs
Publication statusPublished - 1 Jul 2013

Keywords

  • DTI
  • delay discounting
  • frontostriatal tracts
  • impulsivity
  • testosterone

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