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When problem size matters: differential effects of brain stimulation on arithmetic problem solving and neural oscillations.

Rütsche B, Hauser TU, Jäncke L, Grabner RH - PLoS ONE (2015)

Bottom Line: After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems.Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased.These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

View Article: PubMed Central - PubMed

Affiliation: Research on Learning and Instruction, Institute for Behavioral Sciences, ETH Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland.

ABSTRACT
The problem size effect is a well-established finding in arithmetic problem solving and is characterized by worse performance in problems with larger compared to smaller operand size. Solving small and large arithmetic problems has also been shown to involve different cognitive processes and distinct electroencephalography (EEG) oscillations over the left posterior parietal cortex (LPPC). In this study, we aimed to provide further evidence for these dissociations by using transcranial direct current stimulation (tDCS). Participants underwent anodal (30min, 1.5 mA, LPPC) and sham tDCS. After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems. We found that the tDCS effects on performance and oscillatory activity critically depended on the problem size. While anodal tDCS improved response latencies in large arithmetic problems, it decreased solution rates in small arithmetic problems. Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased. These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

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Related in: MedlinePlus

Mean solution rate after anodal and stimulation for small and large problems.Solution rate in small problems was decreased after anodal compared to sham stimulation. Error bars indicate standard errors (SE). *p < 0.05, **p < 0.01.
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pone.0120665.g004: Mean solution rate after anodal and stimulation for small and large problems.Solution rate in small problems was decreased after anodal compared to sham stimulation. Error bars indicate standard errors (SE). *p < 0.05, **p < 0.01.

Mentions: In large problems, we found an improvement in response latencies after anodal (M = 2809 ms, SD = 707) compared to sham stimulation (M = 2989 ms, SD = 842; t(22) = 2.14, p = 0.04, d = 0.45; Fig. 3 left panel). Solution rates in large problems remained unaffected by stimulation (t(22) = 0.50, p = 0.62, d = 0.10; Fig. 4 left panel).


When problem size matters: differential effects of brain stimulation on arithmetic problem solving and neural oscillations.

Rütsche B, Hauser TU, Jäncke L, Grabner RH - PLoS ONE (2015)

Mean solution rate after anodal and stimulation for small and large problems.Solution rate in small problems was decreased after anodal compared to sham stimulation. Error bars indicate standard errors (SE). *p < 0.05, **p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4366159&req=5

pone.0120665.g004: Mean solution rate after anodal and stimulation for small and large problems.Solution rate in small problems was decreased after anodal compared to sham stimulation. Error bars indicate standard errors (SE). *p < 0.05, **p < 0.01.
Mentions: In large problems, we found an improvement in response latencies after anodal (M = 2809 ms, SD = 707) compared to sham stimulation (M = 2989 ms, SD = 842; t(22) = 2.14, p = 0.04, d = 0.45; Fig. 3 left panel). Solution rates in large problems remained unaffected by stimulation (t(22) = 0.50, p = 0.62, d = 0.10; Fig. 4 left panel).

Bottom Line: After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems.Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased.These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

View Article: PubMed Central - PubMed

Affiliation: Research on Learning and Instruction, Institute for Behavioral Sciences, ETH Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland.

ABSTRACT
The problem size effect is a well-established finding in arithmetic problem solving and is characterized by worse performance in problems with larger compared to smaller operand size. Solving small and large arithmetic problems has also been shown to involve different cognitive processes and distinct electroencephalography (EEG) oscillations over the left posterior parietal cortex (LPPC). In this study, we aimed to provide further evidence for these dissociations by using transcranial direct current stimulation (tDCS). Participants underwent anodal (30min, 1.5 mA, LPPC) and sham tDCS. After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems. We found that the tDCS effects on performance and oscillatory activity critically depended on the problem size. While anodal tDCS improved response latencies in large arithmetic problems, it decreased solution rates in small arithmetic problems. Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased. These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

Show MeSH
Related in: MedlinePlus