Visual inhibition of return (IOR) is a mechanism for preventing attention from returning to previously examined spatial locations. Previous studies have found that auditory stimuli presented simultaneously with a visual target can reduce or even eliminate the visual IOR. However, the mechanism responsible for decreased visual IOR accompanied by auditory stimuli is unclear. Using functional magnetic resonance imaging, we aimed to investigate how auditory stimuli reduce visual IOR. Behaviorally, we found that the visual IOR accompanying auditory stimuli was significant but smaller than the visual IOR. Neurally, only in the validly cued trials, the superior temporal gyrus showed increased neural coupling with the intraparietal sulcus, presupplementary motor area, and some other areas in audiovisual conditions compared with visual conditions. These results suggest that the reduction in visual IOR by the simultaneous auditory stimuli may be due to a dual mechanism: rescuing the suppressed visual salience and facilitating response initiation. Our results support crossmodal interactions can occur across multiple neural levels and cognitive processing stages. This study provides a new perspective for understanding attention-orienting networks and response initiation based on crossmodal information.

Motor simulation theory proposes a functional equivalence between motor execution (ME) and its simulation, suggesting that motor imagery (MI) is the self-intentioned simulation of one\'s actions. This study used functional magnetic resonance imaging (fMRI) with multivoxel pattern analysis to test whether the direction of hand movement is represented with a similar neural code between ME and MI. In our study, participants used their right hand to move an on-screen cursor in the left-right direction with a joystick or imagined the same movement without execution. The results indicated that the left-right direction as well as their modality (ME or MI) could be decoded significantly above the chance level in the presupplementary motor area (pre-SMA) and primary visual cortex (V1). Next, we used activation patterns of ME as inputs to the decoder to predict hand move directions in MI sessions and found a significantly higher-than-chance accuracy only in V1, not in pre-SMA. Moreover, the representational similarity analysis showed similar activation patterns for the same directions between ME and MI in V1 but not in pre-SMA. This study\'s finding indicates distinct spatial activation patterns for movement directions between ME and MI in pre-SMA.

Studies using transcranial magnetic stimulation (TMS) have demonstrated the importance of direction and intensity of the applied current when the primary motor cortex (M1) is targeted. By varying these, it is possible to stimulate different subsets of neural elements, as demonstrated by modulation of motor evoked potentials (MEPs) and motor behaviour. The latter involves premotor areas as well, and among them, the presupplementary motor area (pre-SMA) has recently received significant attention in the study of motor inhibition. It is possible that, similar to M1, different neuronal populations can be activated by varying the direction and intensity of TMS; however, the absence of a direct electrophysiological outcome has limited this investigation. The problem can be solved by quantifying direct cortical responses by means of combined TMS and electroencephalography (TMS-EEG). We investigated the effect of variable coil orientations (0°, 90°, 180° and 270°) and stimulation intensities (100%, 120% and 140% of resting motor threshold) on local mean field potential (LMFP), transcranial evoked potential (TEP) peaks and TMS-related spectral perturbation (TRSP) from pre-SMA stimulation. As a result, early and late LMFP and peaks were larger, with the coil handle pointing posteriorly (0°) and laterally (90°). This was true also for TRSP in the β-γ range, but, surprisingly, θ-α TRSP was larger with the coil pointing at 180°. A 90° orientation activated the right M1, as shown by MEPs elicitation, thus limiting the spatial specificity of the stimulation. These results suggest that coil orientation and stimulation intensity are critical when stimulating the pre-SMA.

We are able to temporally organize multiple movements in a purposeful manner in everyday life. Both the dorsal premotor (PMd) area and pre-supplementary motor area (pre-SMA) are known to be involved in the performance of motor sequences. However, it is unclear how each area differentially contributes to controlling multiple motor sequences. To address this issue, we recorded single-unit activity in both areas while monkeys (one male, one female) performed sixteen motor sequences. Each sequence comprised either a series of two identical movements (repetition) or two different movements (nonrepetition). The sequence was initially instructed with visual signals but had to be remembered thereafter. Here, we showed that the activity of single neurons in both areas transitioned from reactive- to predictive encoding while motor sequences were memorized. In the memory-guided trials, in particular, the activity of PMd cells preferentially represented the second movement (2M) in the sequence leading to a reward generally regardless of the first movement (1M). Such activity frequently began even before the 1M in a prospective manner, and was enhanced in nonrepetition sequences. Behaviorally, a lack of the activity enhancement often resulted in premature execution of the 2M. In contrast, cells in pre-SMA instantiated particular sequences of actions by coordinating switching or nonswitching movements in sequence. Our findings suggest that PMd and pre-SMA play complementary roles within behavioral contexts: PMd preferentially controls the movement that leads to a reward rather than the sequence per se, whereas pre-SMA coordinates all elements in a sequence by integrating temporal orders of multiple movements.SIGNIFICANCE STATEMENT Although both dorsal premotor (PMd) area and pre-supplementary motor area (pre-SMA) are involved in the control of motor sequences, it is not clear how these two areas contribute to coordination of sequential movements differently. To address this issue, we directly compared neuronal activity in the two areas recorded while monkeys memorized and performed multiple motor sequences. Our findings suggest that PMd preferentially controls the final action that ultimately leads to a reward in a prospective manner, whereas the pre-SMA coordinates switching among multiple actions within the context of the sequence. Our findings are of significance to understand the distinct roles for motor-related areas in the planning and executing motor sequences and the pathophysiology of apraxia and/or Parkinson\'s diseases that disables skilled motor actions.

Overactive performance monitoring, as reflected by enhanced neural responses to errors (the error-related negativity, ERN), is considered a biomarker for obsessive-compulsive disorder (OCD) and may be a promising target for novel treatment approaches. Prior research suggests that non-invasive brain stimulation with transcranial direct current stimulation (tDCS) may reduce the ERN in healthy individuals, yet no study has investigated its efficacy in attenuating the ERN in OCD. In this preregistered, randomized, sham-controlled, crossover study, we investigated effects of tDCS on performance monitoring in patients with OCD (n = 28) and healthy individuals (n = 28). Cathodal and sham tDCS was applied over the presupplementary motor area (pre-SMA) in two sessions, each followed by electroencephalogram recording during a flanker task. Cathodal tDCS reduced the ERN amplitude compared to sham tDCS, albeit this effect was only marginally significant (p = .052; mean difference: 0.86 μV). Additionally, cathodal tDCS reduced the correct-response negativity and increased the error positivity. These neural modulations were not accompanied by behavioral changes. Moreover, we found no evidence that the tDCS effect was more pronounced in the patient group. In summary, our findings indicate that tDCS over the pre-SMA modulates neural correlates of performance monitoring across groups. Therefore, this study represents a valuable starting point for future research to determine whether repeated tDCS application induces a more pronounced ERN attenuation and normalizes aberrant performance monitoring in the long term, thereby potentially alleviating obsessive-compulsive symptoms and providing a psychophysiological intervention strategy for individuals who do not benefit sufficiently from existing interventions.

Sensorimotor brain areas have been implicated in the recognition of emotion expressed on the face and through nonverbal vocalizations. However, no previous study has assessed whether sensorimotor cortices are recruited during the perception of emotion in speech-a signal that includes both audio (speech sounds) and visual (facial speech movements) components. To address this gap in the literature, we recruited 24 participants to listen to speech clips produced in a way that was either happy, sad, or neutral in expression. These stimuli also were presented in one of three modalities: audio-only (hearing the voice but not seeing the face), video-only (seeing the face but not hearing the voice), or audiovisual. Brain activity was recorded using electroencephalography, subjected to independent component analysis, and source-localized. We found that the left presupplementary motor area was more active in response to happy and sad stimuli than neutral stimuli, as indexed by greater mu event-related desynchronization. This effect did not differ by the sensory modality of the stimuli. Activity levels in other sensorimotor brain areas did not differ by emotion, although they were greatest in response to visual-only and audiovisual stimuli. One possible explanation for the pre-SMA result is that this brain area may actively support speech emotion recognition by using our extensive experience expressing emotion to generate sensory predictions that in turn guide our perception.

Adaptive context-dependent behaviors necessitate the flexible selection of multiple behavioral tactics, i.e., internal protocols for selecting an action. Previous primate studies have shown that the posterior medial prefrontal cortex (pmPFC) contributes to the selection, retention, and use of tactics, but the manner in which this area employs selected tactics to convert sensory information into action and how that manner differs from downstream cortical motor areas have yet to be fully elucidated. To address this issue, the present study recorded neuronal activity in two monkeys as they performed a two-choice arm reaching task that required the selection of multiple tactics when converting spatial cue information into the direction of arm reaching. Neuronal populations in both pmPFC and presupplementary motor area (pre-SMA) represented tactics during their selection, maintenance in memory, and their use in determining an action. Additionally, they represented the monkeys\' action in the behavioral epoch in which the direction of reaching was determined. A striking contrast between the pmPFC and the pre-SMA was the representation of the spatial cue location in the former and its absence in the latter area. In individual neurons, neurons in pmPFC and pre-SMA had either single or mixed representation of tactics and action. Some of the pmPFC neurons additionally encoded cue location. Finally, neurons in the supplementary motor area mainly represented the action. Taken together, the present results indicate that, of these three areas, the pmPFC plays a cardinal role during the integration of behavioral tactics and visuospatial information when selecting an action.

First, an anatomical and functional review of these cortical areas and subcortical connections with T-fMRI and tractography techniques; second, to demonstrate the value of this approach in neurosurgical planning in a series of patients with tumors close to the SMA.
Implications in language and cognitive networks with a clear hemispheric lateralization of these SMA/pre-SMA. The recommendation of the use of the advanced neuroimaging studies for surgical planning and preservation of these areas. The SMA/pre-SMA and their subcortical connections are functional areas to be taken into consideration in neurosurgical planning. These areas would be involved in the control/inhibition of movement, in verbal expression and fluency and in tasks of cognitive control capacity. Its preservation is key to the patient\'s postsurgical cognitive and functional evolution.

Freezing of gait (FOG) in Parkinson\'s disease (PD) is frequently triggered upon passing through narrow spaces such as doorways. However, despite being common the neural mechanisms underlying this phenomenon are poorly understood. In our study, 19 patients who routinely experience FOG performed a previously validated virtual reality (VR) gait paradigm where they used foot-pedals to navigate a series of doorways. Patients underwent testing randomised between both their \"ON\" and \"OFF\" medication states. Task performance in conjunction with blood oxygenation level dependent (BOLD) signal changes between \"ON\" and \"OFF\" states were compared within each patient. Specifically, as they passed through a doorway in the VR environment patients demonstrated significantly longer \"footstep\" latencies in the OFF state compared to the ON state. As seen clinically in FOG this locomotive delay was primarily triggered by narrow doorways rather than wide doorways. Functional magnetic resonance imaging revealed that footstep prolongation on passing through doorways was associated with selective hypoactivation in the presupplementary motor area (pSMA) bilaterally. Task-based functional connectivity analyses revealed that increased latency in response to doorways was inversely correlated with the degree of functional connectivity between the pSMA and the subthalamic nucleus (STN) across both hemispheres. Furthermore, increased frequency of prolonged footstep latency was associated with increased connectivity between the bilateral STN. These findings suggest that the effect of environmental cues on triggering FOG reflects a degree of impaired processing within the pSMA and disrupted signalling between the pSMA and STN, thus implicating the \"hyperdirect\" pathway in the generation of this phenomenon.

Many perceptual decisions are inevitably subject to the tradeoff between speed and accuracy of choices (SAT). Sequential sampling models attribute this ubiquitous relation to random noise in the sensory evidence accumulation process, and assume that SAT is adaptively modulated by altering the decision thresholds at which the level of integrated evidence should reach for making a choice. Although, neuroimaging studies have shown a relationship between right presupplementary motor area (pre-SMA) activity and threshold setting, only a limited number of brain stimulation studies aimed at establishing the causal link, results of which were inconsistent. Additionally, these studies were limited in scope as they only examined the effect of pre-SMA activity unidirectionally through experimentally inhibiting the neural activity in this region. The current study aims to investigate the predictions of the striatal theory of SAT by experimentally assessing the modulatory effect of right pre-SMA on threshold setting bi-directionally. To this end, we applied both offline inhibition and excitation to the right pre-SMA utilizing transcranial magnetic stimulation in a within-subjects design and tested participants on a Random Dot Motion Task. Decision thresholds were estimated using the Hierarchical Drift Diffusion Model. Findings of our planned comparisons showed that right pre-SMA inhibition leads to significantly higher, whereas right pre-SMA excitation leads to significantly lower thresholds without showing any effects on the evidence integration process itself.