Does brain stimulation reliably improve memory and attention?

How do assumptions about cathodal and anodal tDCS effects in the motor cortex compare to findings in cognitive studies?

While cathodal tDCS suppresses and anodal tDCS excites the primary motor cortex, cognitive studies show more complex, sometimes paradoxical results that challenge this simple heuristic.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What is the formula used in the study to calculate Cowan's K for estimating visual working memory capacity?

Cowan's K is calculated by multiplying the set size by the difference between the hit rate and the false alarm rate: K = set size * (hit rate - false alarm rate).

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What was the primary hypothesis tested regarding the right parietal lobe in the authors' visual working memory experiment?

The experiment tested whether cathodal tDCS over the right parietal lobe would disrupt visual working memory grouping mechanisms.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What behavioral effect did the authors replicate in their visual working memory task regarding grouped versus ungrouped stimuli?

They successfully replicated the behavioral grouping benefit, showing that working memory capacity was significantly higher when stimuli were grouped (3-grouped) compared to ungrouped (2-ungrouped).

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What was the primary finding regarding the effect of parietal cathodal tDCS on visual working memory performance in Study 1?

There was no significant main effect of tDCS and no significant interaction between stimulation and condition on visual working memory performance, failing to show any difference from sham.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

How did dividing participants into high and low working memory capacity groups affect the tDCS results in Study 1?

The division did not alter the pattern of results; cathodal tDCS failed to interrupt working memory grouping benefits in both high and low capacity groups.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What participant-related explanation did the authors propose for the null tDCS effects in their visual working memory study?

They suggested that participants (undergraduates seeking extra credit) may not have been effortfully engaged in the task, which led to lower overall performance compared to prior research.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

Why might unilateral stimulation fail to disrupt visual working memory tasks that typically show bilateral fMRI activity?

Contralateral hemisphere compensatory mechanisms might support performance, though the authors note this is unlikely given the right parietal's dominant role in bilateral attention.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What structural or functional brain abnormality in the pre-supplementary motor area (pre-SMA) is associated with ADHD during response inhibition?

Individuals with ADHD show smaller activations in the pre-SMA when performing tasks that require response inhibition.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

How does tDCS over the pre-supplementary motor area (pre-SMA) affect response inhibition in healthy adults in the literature?

Response inhibition is predictably modulated: anodal tDCS improves performance, while cathodal tDCS impairs it.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

Why did the researchers include secondary working memory tasks (OSpan and spatial 2-back) in their ADHD symptomology study?

These tasks served to clarify the specificity of tDCS influences, as they engage frontoparietal networks and were not expected to be modulated by pre-SMA stimulation.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What screening tool did the authors use to evaluate and categorize ADHD symptomology in their undergraduate sample?

The Adult ADHD Self-Report Scale (ASRS-v1.1), specifically focusing on the six screening questions in Part A as they are the most predictive of ADHD.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

Why were participants taking stimulants or antidepressants excluded from the tDCS studies?

These medications modulate the underlying excitability of the brain, which can interact unpredictably with or mask the effects of tDCS.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What are the behavioral mechanics of the Go/No-Go task used in this study to measure response inhibition?

Participants view a letter stream and respond to target letters unless the target letter is an exact repetition of the one that immediately preceded it.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What were the effects of anodal, cathodal, and sham tDCS over the pre-SMA on Go/No-Go performance in Study 2?

The study found no significant main effects of tDCS or ADHD symptomology group, and no interaction effects on accuracy or reaction times.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What were the results of pre-SMA tDCS on the OSpan and spatial 2-back working memory tasks in Study 2?

There was no significant modulation of performance on either the OSpan or the spatial 2-back working memory task across the different tDCS conditions.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What task-related flaw did the authors identify in their Go/No-Go paradigm that may have obscured potential tDCS effects?

The task was not difficult enough, which allowed participants to perform near the ceiling and made it impossible to distinguish between easy and challenging trials.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What problem do the authors highlight as a specific challenge for interpreting the overall efficacy of neurostimulation techniques across cognitive research?

The 'file-drawer' problem, which is the systemic bias against publishing null findings, failed replications, and negative results.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

What is the most consistent and frequently reported finding in published literature regarding tDCS and working memory?

Significant improvements in working memory during verbal n-back tasks when anodal tDCS is applied to the left dorsolateral prefrontal cortex (DLPFC).

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

According to human pharmacological work, which channels and receptors are involved in the long-lasting effects of tDCS?

Blocking sodium or calcium channels prevents the long-lasting effects of anodal tDCS, while blocking NMDA receptors prevents the long-lasting effects of both anodal and cathodal tDCS.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

Why is task difficulty considered critical for demonstrating cognitive modulation with tDCS?

tDCS functions as a tipping factor in borderline, challenging cases; if a task is too easy and performance is definitive, tDCS is unlikely to show any effect.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified

Where do the authors argue tDCS has its greatest potential and clinical value?

Its greatest value lies in translational and applied settings where it can be used to maintain or restore cognitive function across aging and clinical populations.

Source: Hits and misses: leveraging tDCS to advance cognitive research · DOI · quote verified