viernes, 28 de septiembre de 2012

BDNF Val66Met polymorphism and goal-directed behavior in healthy elderly — evidence from auditory distraction


Abstract

Aging affects the ability to focus attention on a given task and to ignore distractors. 
These functions subserve response control processes for which fronto-striatal networks have been shown to play an important role. 

Within these networks, the brain-derived-neurotrophic-factor (BDNF), which is known to underlie aging effects, plays a pivotal role. 

We investigated how cognitive subprocesses constituting a cycle of distraction, orientation and refocusing of attention are affected by the functional BDNF Val66Met polymorphism using event-related potentials (ERPs) in 122 healthy elderly. 

Using an auditory distraction paradigm we found that the Val/Val genotype confers a disadvantage to its carriers. 

This disadvantage was partly compensated by intensified attentional shifting mechanisms. 

It could be based on response selection processes being more vulnerable against interference from distractors in this genotype group. 

Processes reflecting transient sensory memory processes, or the re-orientation of attention were not affected by the BDNF Val66Met polymorphism, suggesting a higher importance of BDNF for mechanisms related to response control, than stimulus processing. 

The results add on recent literature showing that the Met allele confers some benefit to its carriers. 

We suggest an account for unifying different results of BDNF Val66Met association studies in executive functions, based on the role of BDNF in fronto-striatal circuits.

Highlights

► Variations in BDNF Val66Met polymorphism modulate goal-directed behavior. ► The Val/Val genotype confers a disadvantage in elderly. ► This disadvantage can partly be compensated by attentional shifting mechanisms. ► BDNF modulates distinct subprocesses within a distraction and re-focusing cycle.

Keywords

  • Sensory processing;
  • Auditory perception;
  • EEG;
  • BDNF Val66Met polymorphism;
  • Healthy elderly

Corresponding author contact information
Corresponding author at: Leibniz Research Centre for Working Environment and Human Factors, Ardeystraße 67, D-44139 Dortmund, Germany. Fax: + 49 231 1084 401.
  • a Leibniz Research Centre for Working Environment and Human Factors at the Technical University of Dortmund (IfADo), Germany
  • b Institute for Cognitive Neuroscience, Biopsychology, Ruhr-University Bochum, Germany
 

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