The modulatory role of pre-SMA in speed-accuracy tradeoff: A bi-directional TMS study

Characterizing the role of the pre‐SMA in the control of speed/accuracy trade‐off with directed functional connectivity mapping and multiple solution reduction

“…Taken together, this pattern of findings suggests that the pre‐SMA serves as the primary region involved in the coordination of SAT, consistent with previous research using univariate fMRI (Forstmann et al, , , ; Mansfield et al, ) and transcranial magnetic stimulation (Berkay et al, ; Georgiev et al, ; Tosun et al, ). It makes a crucial extension of this work by being the first directed functional connectivity analysis to provide evidence that the pre‐SMA implements adjustments to SAT by sending top‐down control signals to an array of other regions, and coordinates SAT in response to a higher‐order control signal from the DLPFC.…”

“…Neural activity in the pre‐SMA as measured by functional magnetic resonance imaging (fMRI) and the integrity of white matter connections between this region and striatum have both been found to display a correlational relationship with individual differences in SAT‐related distance‐to‐threshold changes, as measured by parameters from bounded accumulator models (Forstmann et al, , , ; Mansfield, Karayanidis, Jamadar, Heathcote, & Forstmann, ). Furthermore, transcranial magnetic stimulation of the right pre‐SMA has been repeatedly demonstrated to experimentally alter the same parameters (Berkay, Eser, Sack, Çakmak, & Balcı, ; Georgiev et al, ; Tosun, Berkay, Sack, Çakmak, & Balcı, ). However, a comprehensive understanding of the pre‐SMA's role in SAT is currently lacking, in part because the strength and directionality of functional connections between this region and other regions believed to be involved in the control of SAT, as well as with those linked to evidence accumulation and motor thresholding, is currently unclear.…”

Differential Bilateral Primary Motor Cortex tDCS Fails to Modulate Choice Bias and Readiness in Perceptual Decision Making

“…The absence of an effect of tDCS over the primary motor cortex on motor behavior presents an interesting parallelism to the differential findings regarding the effect of tDCS vs. transcranial magnetic stimulation (specifically, theta burst stimulation) of the right preSMA on decision threshold settings. Two recent studies have shown that the inhibition of right preSMA via continuous theta burst stimulation ( Tosun et al, 2017 ; Berkay et al, 2018 ) leads to higher decision threshold settings whereas the stimulation of the same brain area via intermittent theta burst stimulation ( Berkay et al, 2018 ) leads to lower decision threshold settings. Interestingly, however, in three independent studies Hollander et al (2016) showed that tDCS of pre-SMA by the placement of the anodal electrode on FCZ did not produce any effects on threshold settings.…”

“…These two core parameters of DDM estimated from the shape of the correct and error RT distributions, as well as their relative density, were shown to be sensitive to the signal-to-noise ratio in sensory information (e.g., higher drift rates for high signal-to-noise ratio; Balcı et al, 2011 ) and differential emphasis on speed vs. accuracy (e.g., higher thresholds when accuracy is emphasized; Bogacz et al, 2010 ). A number of neuroimaging and brain stimulation studies have implicated the fronto-parietal pathways for the modulation of the drift rate and the pre-supplementary motor area for the modulation of the decision thresholds ( Mulder et al, 2014 ; Tosun et al, 2017 ; Berkay et al, 2018 ).…”

“…They also observed a modulatory effect of brain stimulation on the response times of the left hand (non-dominant hand in their sample) in correct trials. However, they did not investigate the effect of their brain stimulation manipulations on the latent decision-making processes, which provide a more decision theoretically grounded characterization of the presumed effects based on the unified analysis of the decision accuracy and associated response times (e.g., Tosun et al, 2017 ; Berkay et al, 2018 ).…”