Research reportIndividual response speed is modulated by variants of the gene encoding the alpha 4 sub-unit of the nicotinic acetylcholine receptor (CHRNA4)

- We studied the effect of the CHRNA4 rs1044396 polymorphism (C/T) on response speed and selective attention in three behavioral tasks.
- The effects on response speed were uniformly consistent: Reaction times increased in dependence of the C allele dosage.
- No effects of this polymorphism on selective attention were noted.
- We show that the nicotinic acetylcholine receptor influences the speed of information processing.

Acetylcholine (ACh) is a known modulator of several domains of cognition, among them attention, memory and learning. The neurotransmitter also influences the speed of information processing, particularly the detection of targets and the selection of suitable responses. We examined the effect of the rs1044396 (C/T) polymorphism of the gene encoding the nicotinic acetylcholine receptor α4-subunit (CHRNA4) on response speed and selective visual attention. To this end, we administered a Stroop task, a Negative priming task and an exogenous Posner-Cuing task to healthy participants (n = 157). We found that the CHRNA4 rs1044396 polymorphism modulated the average reaction times (RTs) across all three tasks. Dependent on the C allele dosage, the RTs linearly increased. Homozygous T allele carriers were always fastest, while homozygous C allele carriers were always slowest. We did not observe effects of this polymorphism on selective attention. In sum, we conclude that naturally occurring variations within the cholinergic system influence an important factor of information processing. This effect might possibly be produced by the neuromodulator system rather than the deterministic system of cortical ACh.