tVNS paired with easier-to-learn categories increases retention of correct stimulus-response associations between training blocks¶

Claim · All claims
Evidence · 1 study · causal r1 · q3
Currency · newest study 2020 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? The tVNS-easy group retained a larger percentage of correct categorization trials between consecutive blocks (significant for Blocks 3–5, marginal for Block 6), while the tVNS-hard group did not differ from Control. → Llanos 2020

Evidence¶

Llanos 2020¶

Llanos, F., McHaney, J. R., Schuerman, W. L., Yi, H. G., Leonard, M. K. and Chandrasekaran, B. (2020). Non-invasive peripheral nerve stimulation selectively enhances speech category learning in adults. npj Science of Learning. https://doi.org/10.1038/s41539-020-0070-0

q3 · i? · causal · r1

Linear mixed-effects model of percentages of trials correctly categorized on block n and block n-1, starting at Block 2. The tVNS-easy group-by-block interaction was significant for Blocks 3–5; the tVNS-hard group interaction was not significant for any block (p > 0.05).

"In contrast, the interaction for the tVNS-easy group was signi ficant for all blocks but the last one (Block 3: β = 13.95, z = 2.42, p = 0.016; Block 4: β = 15.52, z = 2.69, p = 0.007; Block 5: β = 16.04, z = 2.78, p = 0.006; Block 6: β = 11.35, z = 1.97, p = 0.0505 Fig. 2d)."

Discussion¶

Related Claims¶

• Brief tVNS paired with speech training produces no measurable change in the sensory representation of non-native pitch as indexed by frequency-following responses — related
• Sub-perceptual-threshold tVNS evokes brainstem vagal potentials consistent with peripheral nerve engagement, and the pulse-evoked response follows an inverted-U function of stimulation intensity — related
• Pairing sub-perceptual tVNS with easier-to-learn Mandarin tone categories improves trial-by-trial speech category learning faster than training alone, and the enhancement is specific to the stimulated categories — related
• The tVNS-easy group's performance falls outside the normal range of individual learning variability observed across 678 comparable unstimulated learners — related
• Pairing tVNS with feedback after correct responses does not enhance speech category learning, suggesting the enhancement is not driven by a reward signal — related
• tVNS-enhanced speech category learning generalizes to new talkers' exemplars without accompanying stimulation or feedback — related