Prefrontal cortex activation during incremental inspiratory loading in healthy participants

Background: The present study aimed to examine the acute neurophysiological effects of 1Hz transcranial magnetic stimulation (TMS) administered to the right dorsolateral prefrontal cortex (DLPFC) in healthy participants. Methods: TMS combined with simultaneous electroencephalography (EEG) recording was conducted for 21 healthy participants. For the right DLPFC, 1Hz-TMS (100 pulses/block × 17 sessions) was applied in the resting-state, while for the left DLPFC, 1Hz-TMS (100 pulses/block × 2 sessions) was administered during the verbal fluency tasks (VFTs). For TMS-EEG data, independent component analysis (ICA) was applied to extract TMS-evoked EEG potentials to calculate TMS-related power as well as TMS-related coherence from the F4 and F3 electrode sites during the resting-state and VFTs. Results: TMS-related power was significantly increased in alpha, beta, and gamma bands by 1Hz-TMS at the stimulation site during the resting-state, while TMS-related power was significantly increased in alpha and beta bands but not in the gamma band during the VFTs. On the other hand, TMS-related coherence in alpha and beta bands significantly increased but not in gamma band by 1Hz-TMS that was administered to the right DLPFC in resting-state, whereas there were no significant changes in coherence for all frequency bands by 1Hz-TMS that applied to the left DLPFC during the VFTs. Conclusions: Collectively, 1Hz-repetitive TMS (rTMS) to the right DLPFC may rapidly neuromodulate EEG activity, which might be associated with a therapeutic mechanism for depression.

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The Effects of Prior Cognitive Control Task Exposure on Responses to Emotional Tasks in Healthy Participants

Behavioural and Cognitive Psychotherapy ◽

10.1017/s1352465810000652 ◽

2010 ◽

Vol 39 (2) ◽

pp. 205-220 ◽

Cited By ~ 16

Author(s):

Amanda W. Calkins ◽

Christen M. Deveney ◽

Meara L. Weitzman ◽

Bridget A. Hearon ◽

Greg J. Siegle ◽

...

Keyword(s):

Prefrontal Cortex ◽

Cognitive Control ◽

Mood Induction ◽

Peripheral Vision ◽

Training Session ◽

Future Research ◽

Comparison Task ◽

Emotional Challenge ◽

Computer Based ◽

Healthy Participants

Background: Recent advances have been made in the application of cognitive training strategies as interventions for mental disorders. One novel approach, cognitive control training (CCT), uses computer-based exercises to chronically increase prefrontal cortex recruitment. Activation of prefrontal control mechanisms have specifically been identified with attenuation of emotional responses. However, it is unclear whether recruitment of prefrontal resources alone is operative in this regard, or whether prefrontal control is important only in the role of explicit emotion regulation. This study examined whether exposure to cognitive tasks before an emotional challenge attenuated the effects of the emotional challenge. Aims: We investigated whether a single training session could alter participants' reactivity to subsequent emotional stimuli on two computer-based tasks as well as affect ratings made during the study. We hypothesized that individuals performing the Cognitive Control (CC) task as compared to those performing the Peripheral Vision (PV) comparison task would (1) report reduced negative affect following the mood induction and the emotion task, and (2) exhibit reduced reactivity (defined by lower affective ratings) to negative stimuli during both the reactivity and recovery phases of the emotion task and (3) show a reduced bias towards threatening information. Method: Fifty-nine healthy participants were randomized to complete CC tasks or PV, underwent a negative mood induction, and then made valence and arousal ratings for IAPS images, and completed an assessment of attentional bias. Results: Results indicated that a single-session of CC did not consistently alter participants' responses to either task. However, performance on the CC tasks was correlated on subsequent ratings of emotional images. Conclusions: While overall these results do not support the idea that affective responding is altered by making healthy volunteers use their prefrontal cortex before the affective task, they are discussed in the context of study design issues and future research directions.

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When Brain Stimulation Backfires

10.31219/osf.io/jv9bc ◽

2020 ◽

Author(s):

Sarah Beth Bell ◽

Brian Turner ◽

Lumy Sawaki ◽

C. Nathan DeWall

Keyword(s):

Prefrontal Cortex ◽

Individual Differences ◽

Direct Current ◽

Brain Stimulation ◽

Stop Signal Task ◽

Impulsive Behavior ◽

Trait Impulsivity ◽

Behavior Scale ◽

Healthy Participants ◽

Intended Effect

Transcranial direct current stimulation can sometimes cause the opposite of its intended effect. These reverse effects may be related in part to individual differences in personality and neurochemistry. Previous studies have demonstrated that dopamine levels can impact the effects of tDCS. In the present study, 124 healthy participants took the UPPS Impulsive Behavior scale. Participants then underwent a single, randomized anodal or sham tDCS session on the prefrontal cortex. While the effects of tDCS were still active, they performed the Stop Signal Task, a measure of state impulsivity. tDCS was associated with increased errors on this task in people who had higher scores on the UPPS in two facets of impulsivity that correlate with dopamine levels. tDCS had no effects on people low in trait impulsivity. These results suggest that the reverse effects of tDCS could be associated with inter-individual differences in personality and neurochemistry.

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T54. EFFECTS OF GAMMA TRANSCRANIAL ALTERNATING CURRENT STIMULATION TO THE LEFT DORSOLATERAL PREFRONTAL CORTEX ON WORKING MEMORY IN SCHIZOPHRENIA PATIENTS

Schizophrenia Bulletin ◽

10.1093/schbul/sbaa029.614 ◽

2020 ◽

Vol 46 (Supplement_1) ◽

pp. S251-S252

Author(s):

Irina Papazova ◽

Wolfgang Strube ◽

Lina Hoffmann ◽

Tobias Schwippel ◽

Frank Padberg ◽

...

Keyword(s):

Working Memory ◽

Prefrontal Cortex ◽

Cognitive Load ◽

Dorsolateral Prefrontal Cortex ◽

Reaction Times ◽

Alternating Current ◽

Primary Study ◽

Dorsolateral Prefrontal ◽

Transcranial Alternating Current Stimulation ◽

Healthy Participants

Abstract Background Working memory (WM) impairment is characteristic for schizophrenia patients, lowering their occupational status and quality of life. Recent research suggests that non-invasive brain stimulation could have the potential to treat such cognitive deficits. One novel and promising approach is the transcranial alternating current stimulation (tACS) that could entrain the endogenous gamma oscillations in the dorsolateral prefrontal cortex (DLPFC), previously shown to be abnormal in schizophrenia patients and associated with WM deficits. Indeed, first studies demonstrated WM improvement in healthy participants following tACS at the gamma frequency (γ-tACS) to the DLPFC in healthy participants. However, till date, there is only one pilot study with ten schizophrenia patients, where cognitive enhancement was not evident. Here, we aimed to investigate the efficacy and feasibility of γ-tACS on simultaneous WM performance in schizophrenia patients with a bigger study sample and in regard of cognitive load Methods A total of fifteen patients with schizophrenia (N = 15, 8 female) participated in the current study. They underwent a pre-stimulation baseline, an active γ-tACS and a sham single-session in a double-blind, cross-over design. Stimulation was administered over the left DLPFC (F3, anode) and the contralateral region (F4, cathode) at a current of -1mA to 1mA (peek-to-peek) at 40 Hz for 20 min (48000 cycles). We assessed WM during stimulation using a verbal n-back task with three cognitive loads (1- to 3-back). Reaction times and discriminability index d prime served as primary study outcomes. Using several RM-ANOVAs, we compared working memory performance during γ-tACS and sham across all cognitive loads. Results Data analysis showed no significant main effect of γ-tACS compared to sham on both d prime values (p = .269) and reaction times (p = .166). However, we observed a significant stimulation x load interaction effect on reaction times (p = .043), suggesting that with increasing cognitive load participants responded slightly slower during active than during sham γ-tACS. Discussion The current work is one of the first to investigate the effects of γ-tACS to the DLPFC on simultaneous WM performance in schizophrenia patients. In line with previous research, we did not find any significant changes in cognition due to stimulation. Surprisingly, we observed a slight decrease in WM speed with higher cognitive load during active compared to sham tACS. Results are discussed in line of study protocol and tACS feasibility and emphasize the need for future research on the specific study design parameters.

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When brain stimulation backfires: the effects of prefrontal cortex stimulation on impulsivity

Social Cognitive and Affective Neuroscience ◽

10.1093/scan/nsaa049 ◽

2020 ◽

Author(s):

Sarah Beth Bell ◽

Brian Turner ◽

Lumy Sawaki ◽

Nathan DeWall

Keyword(s):

Prefrontal Cortex ◽

Individual Differences ◽

Direct Current ◽

Brain Stimulation ◽

Stop Signal Task ◽

Impulsive Behavior ◽

Trait Impulsivity ◽

Behavior Scale ◽

Healthy Participants ◽

Intended Effect

Abstract Transcranial direct current stimulation (tDCS) can sometimes cause the opposite of its intended effect. These reverse effects may be related in part to individual differences in personality and neurochemistry. Previous studies have demonstrated that dopamine levels can impact the effects of tDCS. In the present study, 124 healthy participants took the UPPS impulsive behavior scale. Participants then underwent a single, randomized anodal or sham tDCS session on the prefrontal cortex. While the effects of tDCS were still active, they performed the Stop Signal Task, a measure of state impulsivity. tDCS was associated with increased errors on this task in people who had higher scores on the UPPS in two facets of impulsivity that correlate with dopamine levels. tDCS had no effects on people who are low in trait impulsivity. These results suggest that the reverse effects of tDCS could be associated with inter-individual differences in personality and neurochemistry.

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Role of the prefrontal cortex in prosocial and self-maximization motivations: an rTMS study

Scientific Reports ◽

10.1038/s41598-021-01588-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Oksana Zinchenko ◽

Olga Savelo ◽

Vasily Klucharev

Keyword(s):

Prefrontal Cortex ◽

Prosocial Behavior ◽

Dictator Game ◽

Prosocial Motives ◽

Dorsolateral Prefrontal ◽

The Right ◽

Theta Burst ◽

Continuous Theta Burst Stimulation ◽

Healthy Participants

AbstractMore than a decade of neuroimaging and brain stimulation studies point to a crucial role for the right dorsolateral prefrontal cortex (rDLPFC) in prosocial behavior. The intuitive prosociality model postulates that the rDLPFC controls intuitive prosocial behavior, whereas the reflective model assumes that the rDLPFC controls selfish impulses during prosocial behavior. The intuitive prosociality model implies that the transient disruption of the rDLPFC should increase voluntary transfers in both dictator and generosity games. In contrast, the reflective model suggests that the transient disruption of the rDLPFC should decrease transfers in the dictator game, without affecting voluntary transfers in the generosity game, in which selfish motives are minimized. The aim of this paper was to compare predictions of the intuitive and reflective models using the classic dictator game and generosity game and continuous theta burst stimulation (cTBS). In this study, two groups of healthy participants (dictators) received either cTBS over the rDLPFC or right extrastriate visual areas. As shown by the results, the transient disruption of the rDLPFC significantly promoted prosocial motives in the dictator game only, particularly in the trials with the lowest dictator’s costs. These findings partially support the notion that the rDLPFC controls intuitive prosocial behavior.

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The relationship between brain cortical activity and brain oxygenation in the prefrontal cortex during hypergravity exposure

Journal of Applied Physiology ◽

10.1152/japplphysiol.01426.2012 ◽

2013 ◽

Vol 114 (7) ◽

pp. 905-910 ◽

Cited By ~ 14

Author(s):

Craig Smith ◽

Nandu Goswami ◽

Ryan Robinson ◽

Melanie von der Wiesche ◽

Stefan Schneider

Keyword(s):

Prefrontal Cortex ◽

Near Infrared ◽

Brain Activity ◽

Cortical Activity ◽

Brain Oxygenation ◽

Electromagnetic Tomography ◽

Long Duration ◽

The Central Nervous System ◽

The Relationship ◽

Healthy Participants

Artificial gravity has been proposed as a method to counteract the physiological deconditioning of long-duration spaceflight; however, the effects of hypergravity on the central nervous system has had little study. The study aims to investigate whether there is a relationship between prefrontal cortex brain activity and prefrontal cortex oxygenation during exposure to hypergravity. Twelve healthy participants were selected to undergo hypergravity exposure aboard a short-arm human centrifuge. Participants were exposed to hypergravity in the +Gz axis, starting from 0.6 +Gz for women, and 0.8 +Gz for men, and gradually increasing by 0.1 +Gz until the participant showed signs of syncope. Brain cortical activity was measured using electroencephalography (EEG) and localized to the prefrontal cortex using standard low-resolution brain electromagnetic tomography (LORETA). Prefrontal cortex oxygenation was measured using near-infrared spectroscopy (NIRS). A significant increase in prefrontal cortex activity ( P < 0.05) was observed during hypergravity exposure compared with baseline. Prefrontal cortex oxygenation was significantly decreased during hypergravity exposure, with a decrease in oxyhemoglobin levels ( P < 0.05) compared with baseline and an increase in deoxyhemoglobin levels ( P < 0.05) with increasing +Gz level. No significant correlation was found between prefrontal cortex activity and oxy-/deoxyhemoglobin. It is concluded that the increase in prefrontal cortex activity observed during hypergravity was most likely not the result of increased +Gz values resulting in a decreased oxygenation produced through hypergravity exposure. No significant relationship between prefrontal cortex activity and oxygenation measured by NIRS concludes that brain activity during exposure to hypergravity may be difficult to measure using NIRS. Instead, the increase in prefrontal cortex activity might be attributable to psychological stress, which could pose a problem for the use of a short-arm human centrifuge as a countermeasure.

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