When problem size matters: differential effects of brain stimulation on arithmetic problem solving and neural
Bruno Rütsche1, Tobias U Hauser2, Lutz Jäncke3
1Research on Learning and Instruction, Institute for Behavioral Sciences, ETH Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland.
Plos One
|March 20, 2015
Summary
Brain stimulation using transcranial direct current stimulation (tDCS) impacts arithmetic problem-solving differently based on problem size. Anodal tDCS improved performance on large problems but hindered small ones, showing distinct cognitive processes.
Area of Science:
- Cognitive Neuroscience
- Neuroscience
- Psychology
Background:
- The problem size effect in arithmetic is characterized by reduced performance with larger operands.
- Distinct cognitive processes and electroencephalography (EEG) oscillations in the left posterior parietal cortex (LPPC) are associated with solving small versus large arithmetic problems.
Purpose of the Study:
- To investigate the differential involvement of the LPPC in solving small and large arithmetic problems.
- To examine the effects of transcranial direct current stimulation (tDCS) on cognitive processes underlying arithmetic problem-solving.
Main Methods:
- Participants received anodal or sham tDCS over the LPPC.
- Neural activity was recorded using EEG during the solving of small and large arithmetic problems post-stimulation.
Main Results:
- Anodal tDCS improved response latencies for large arithmetic problems but decreased solution rates for small problems.
- EEG data showed increased lower-alpha desynchronization in large problems and decreased theta synchronization in small problems following tDCS.
- The effects of tDCS on performance and neural oscillations were dependent on arithmetic problem size.
Conclusions:
- The LPPC plays a differential role in solving small and large arithmetic problems.
- The impact of brain stimulation techniques like tDCS on cognitive functions is contingent upon the underlying neuro-cognitive processes involved.
