Use of transcranial magnetic stimulation (TMS) for studying cognitive control in depressed patients: A systematic review.

Major depressive disorder (MDD) is a debilitating mental disorder and the leading cause of disease burden. Major depressive disorder is associated with emotional impairment and cognitive deficit. Cognitive control, which is the ability to use perceptions, knowledge, and information about goals and motivations to shape the selection of goal-directed actions or thoughts, is a primary function of the prefrontal cortex (PFC). Psychotropic medications are one of the main treatments for MDD, but they are not effective for all patients. An alternative treatment is transcranial magnetic stimulation (TMS). Previous studies have provided mixed results on the cognitive-enhancing effects of TMS treatment in patients with MDD. Some studies have found significant improvement, while others have not. There is a lack of understanding of the specific effects of different TMS protocols and stimulation parameters on cognitive control in MDD. Thus, this review aims to synthesize the effectiveness of the TMS methods and a qualitative assessment of their potential benefits in improving cognitive functioning in patients with MDD. We reviewed 21 studies in which participants underwent a treatment of any transcranial magnetic stimulation protocol, such as repetitive TMS or theta-burst stimulation. One of the primary outcome measures was any change in the cognitive control process. Overall, the findings indicate that transcranial magnetic stimulation (TMS) may enhance cognitive function in patients with MDD. Most of the reviewed studies supported the notion of cognitive improvement following TMS treatment. Notably, improvements were predominantly observed in inhibition, attention, set shifting/flexibility, and memory domains. However, fewer significant improvements were detected in evaluations of visuospatial function and recognition, executive function, phonemic fluency, and speed of information processing. This review found evidence supporting the use of TMS as a treatment for cognitive deficits in patients with MDD. The results are promising, but further research is needed to clarify the specific TMS protocol and stimulation locations that are most effective.

Prefronto-cerebellar neuromodulation affects appetite in obesity.

Human neuroimaging studies have consistently reported changes in cerebellar function and integrity in association with obesity. To date, however, the nature of this link has not been studied directly. Emerging evidence suggests a role for the cerebellum in higher cognitive functions through reciprocal connections with the prefrontal cortex. The purpose of this exploratory study was to examine appetite changes associated with noninvasive prefronto-cerebellar neuromodulation in obesity. Totally, 12 subjects with class I obesity (mean body mass index 32.9 kg/m2) underwent a randomized, single-blinded, sham-controlled, crossover study, during which they received transcranial direct current stimulation ((tDCS); active/sham) aimed at simultaneously enhancing the activity of the prefrontal cortex and decreasing the activity of the cerebellum. Changes in appetite (state and food-cue-triggered) and performance in a food-modified working memory task were evaluated. We found that active tDCS caused an increase in hunger and desire to eat following food-cue exposure. In line with these data, subjects also tended to make more errors during the working memory task. No changes in basic motor performance occurred. This study represents the first demonstration that prefronto-cerebellar neuromodulation can influence appetite in individuals with obesity. While preliminary, our findings support a potential role for prefronto-cerebellar pathways in the behavioral manifestations of obesity.

Inhibitory control failures and blunted cortisol response to psychosocial stress in amphetamine consumers after 6 months of abstinence.

BACKGROUND: Amphetamine abuse has been conceived as an addictive illness where stress regulation and inhibitory control may be crucial factors determining chronicity and relapse. Since amphetamine consumption may disrupt the cerebral systems regulating inhibition and stress behaviors, deregulation on these systems may be expected even after long-term abstinence periods. The present study aimed to evaluate the ability of abstinent amphetamine consumers to regulate stress parameters and to inhibit cognitive patterns under the acute trier social stress test (TSST) paradigm. MATERIALS AND METHODS: A cohort study was conducted in a sample of 44 young individuals (average age: 24.6 years). The sample included 22 amphetamine consumers recruited from an addiction treatment center and 22 healthy nonconsumers belonging to the same sociodemographic conditions. Both groups were exposed to the TSST once the consumers completed 6 months in abstinence. To evaluate stress reactivity, we collected five saliva samples distributed before, during, and after stress exposure. Inhibitory capacity was also assessed before and after stress using the Stroop and d2 cancellation tests. RESULTS: Under stress conditions, cortisol measures were significantly lower in amphetamine consumers (1105.34 ± 756.958) than in healthy nonconsumers (1771.86 ± 1174.248) P = 0.022. Without stress, amphetamine consumers also showed lower cortisol values (1027.61 ± 709.8) than nonconsumers (1844.21 ± 1099.15) P = 0.016. Regarding inhibitory capacity, stress also was associated to consumer's lower scores on the Stroop (5.17 ± 8.34 vs. 10.58 ± 7.83) P = 0.032 and d2 tests (190.27 ± 29.47 vs. 218.00 ± 38.08) P = 0.010. CONCLUSION: We concluded that both the stress regulatory system and executive function system (attentional/inhibitory control) represent key vulnerability conditions to the long-term effect of compulsive amphetamine consumption.

Visual EMDR stimulation mitigates acute varied stress effects on morphology of hippocampal neurons in male Wistar rats.

Introduction: Stress is a pervasive health concern known to induce physiological changes, particularly impacting the vulnerable hippocampus and the morphological integrity of its main residing cells, the hippocampal neurons. Eye Movement Desensitization and Reprocessing (EMDR), initially developed to alleviate emotional distress, has emerged as a potential therapeutic/preventive intervention for other stress-related disorders. This study aimed to investigate the impact of Acute Variable Stress (AVS) on hippocampal neurons and the potential protective effects of EMDR. Methods: Rats were exposed to diverse stressors for 7 days, followed by dendritic morphology assessment of hippocampal neurons using Golgi-Cox staining. Results: AVS resulted in significant dendritic atrophy, evidenced by reduced dendritic branches and length. In contrast, rats receiving EMDR treatment alongside stress exposure exhibited preserved dendritic morphology comparable to controls, suggesting EMDR's protective role against stressinduced dendritic remodeling. Conclusions: These findings highlight the potential of EMDR as a neuroprotective intervention in mitigating stress-related hippocampal alterations.

New functional dissociations between prefrontal and parietal cortex during task switching: A combined fMRI and TMS study.

Preparatory control in task-switching has been suggested to rely upon a set of distributed regions within a frontoparietal network, with frontal and parietal cortical areas cooperating to implement switch-specific preparation processes. Although recent causal evidence using transcranial magnetic stimulation (TMS) have generally supported this model, alternative results from both functional neuroimaging and neurophysiological studies have questioned the switch-specific role of both frontal and parietal cortices. The aim of the present study was to clarify the involvement of prefrontal and parietal areas in preparatory cognitive control. With this purpose, an fMRI study was conducted to identify the brain areas activated during cue events in a task-switching paradigm, indicating whether to switch or to repeat among numerical tasks. Then, TMS was applied over the specific coordinates previously identified through fMRI, that is, the right inferior frontal gyrus (IFG) and right intraparietal sulcus (IPS). Results revealed that TMS over the right IFG disrupted performance in both switch and repeat trails in terms of delayed responses as compared to Sham condition. In contrast, TMS over the right IPS selectively interfered performance in switch trials. These findings support a multi-component model of executive control with the IFG being involved in more general switch-unspecific process such as the episodic retrieval of goals, and the IPS being related to the implementation of switch-specific preparation mechanisms for activating stimulus-response mappings. The results are discussed within the framework of contemporary hierarchical models of prefrontal cortex organization, suggesting that distinct prefrontal areas may carry out coordinated functions in preparatory control.

A comparison of PTSD and traumatic event rates in a clinical sample of non-refugee immigrants and native-born individuals with a psychotic disorder: a case-control study.

Background: Migration is a multi-stage social process linked to traumatic event exposure and a notably increased risk of psychosis. Although these conditions affect refugee and non-refugee immigrants, prior trauma research has focused mainly on the refugee population.Objective: To compare and describe the rate and the clinical characterization of PTSD and traumatic events between non-refugee immigrants and native-born individuals with psychotic disorder.Methods: 99 immigrants and 99 native-born individuals (n = 198) with at least one psychotic episode according to DSM-5 criteria were compared on the rate of PTSD diagnosis and traumatic events, using standardized and validated trauma scales.Results: In the non-refugee immigrant group, 31% met diagnostic criteria for PTSD compared to only 7.1% in the native-born group. Total scores in childhood trauma and last year stressful events were 1.5 and 2 times higher in non-refugee immigrants, respectively. Likewise, cumulative lifetime trauma was three times higher in non-refugee immigrants. Finally, non-refugee immigrants reported more violent and life-threatening traumatic events than native-born individuals.Conclusions: These results are relevant since they highlight that non-refugee immigrants with psychotic disorders are highly trauma-exposed, meaning a routine trauma assessment and a trauma-focused intervention for this population should be included in individualized treatment plans.

Traumatic events and PTSD rates in the non-refugee immigrant population with psychotic disorder have previously received scant attention.This study found that in a psychotic population, 31% of the non-refugee immigrants presented a PTSD diagnosis compared to only 7.1% of the native-born individuals.Compared to native-born individuals with psychosis, non-refugee immigrants with psychosis have 1.5 times more childhood trauma exposure, 2 times more stressful events in the past year and 3 times more cumulative trauma over their lifetime.

Effects of prefrontal and parietal neuromodulation on magnitude processing and integration.

Numerical cognition is an essential skill for survival, which includes the processing of discrete and continuous quantities, involving a mainly right fronto-parietal network. However, the neurocognitive systems underlying the processing and integration of discrete and continuous quantities are currently under debate. Noninvasive brain stimulation techniques have been used in the study of the neural basis of numerical cognition with a spatial, temporal and functional resolution superior to other neuroimaging techniques. The present randomized sham-controlled single-blinded trial addresses the involvement of the right dorsolateral prefrontal cortex and the right intraparietal sulcus in magnitude processing and integration. Multifocal anodal transcranial direct current stimulation was applied online during the execution of magnitude comparison tasks in three conditions: right prefrontal, right parietal and sham stimulation. The results show that prefrontal stimulation produced a moderated decrease in response times in all magnitude processing and integration tasks compared to sham condition. While parietal stimulation had no significant effect on any of the tasks. The effect found is interpreted as a generalized improvement in processing speed and magnitude integration due to right prefrontal neuromodulation, which may be attributable to domain-general or domain-specific factors.

Effects of Caffeine Consumption on Attention Deficit Hyperactivity Disorder (ADHD) Treatment: A Systematic Review of Animal Studies.

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity. ADHD impairments arise from irregularities primarily in dopamine (DA) and norepinephrine (NE) circuits within the prefrontal cortex. Due to ADHD medication's controversial side effects and high rates of diagnosis, alternative/complementary pharmacological therapeutic approaches for ADHD are needed. Although the number of publications that study the potential effects of caffeine consumption on ADHD treatment have been accumulating over the last years, and caffeine has recently been used in ADHD research in the context of animal models, an updated evidence-based systematic review on the effects of caffeine on ADHD-like symptoms in animal studies is lacking. To provide insight and value at the preclinical level, a systematic review based on PRISMA guidelines was performed for all publications available up to 1 September 2021. Caffeine treatment increases attention and improves learning, memory, and olfactory discrimination without altering blood pressure and body weight. These results are supported at the neuronal/molecular level. Nonetheless, the role of caffeine in modulating ADHD-like symptoms of hyperactivity and impulsivity is contradictory, raising discrepancies that require further clarification. Our results strengthen the hypothesis that the cognitive effects of caffeine found in animal models could be translated to human ADHD, particularly during adolescence.

Use of transcranial magnetic stimulation for studying the neural basis of numerical cognition: A systematic review.

Complex numerical cognition is a crucial ability in the human brain. Conventional neuroimaging techniques do not differentiate between epiphenomena and neuronal groups critical to numerical cognition. Transcranial magnetic stimulation (TMS) allows defining causal models of the relationships between specific activated or inhibited neural regions and functional changes in cognition. However, there is insufficient knowledge on the differential effects of various TMS protocols and stimulation parameters on numerical cognition. This systematic review aimed to synthesize the evidence that different TMS protocols provide regarding the neural basis of numerical cognition in healthy adults. We included 21 experimental studies in which participants underwent any transcranial magnetic stimulation such as a single pulse TMS, repetitive TMS, and theta-burst stimulation. The primary outcome measures were any change in numerical cognition processes evidenced by numerical or magnitude tasks, measured with any independent variable like reaction times, accuracy, or congruency effects. TMS applied to regions of the parietal cortex and prefrontal cortex has neuromodulatory effects, which translate into measurable behavioral effects affecting cognitive functions related to arithmetic and numerical and magnitude processing. The use of TMS for the study of the neural bases of numerical cognition allows addressing issues such as localization, timing, lateralization and has allowed establishing site-function dissociations and double site-function dissociations. Moreover, this technique is in a moment of expansion due to the growing knowledge of its physiological effects and the enormous potential of combining TMS with other techniques such as electroencephalography, functional magnetic resonance imaging, or near-infrared spectroscopy to reach a more precise brain mapping.

Prevalence and Characterization of Psychological Trauma in Patients with Fibromyalgia: A Cross-Sectional Study.

Background: Preliminary evidence suggests that psychological trauma, especially childhood trauma, is a risk factor for the onset of fibromyalgia (FM). Objective: The main objective of this study consisted of evaluating the prevalence and detailed characteristics of psychological trauma in a sample of patients with FM, the chronology of trauma across the lifespan, and its clinical symptoms. We also calculated whether childhood trauma could predict the relationship with different clinical variables. Method: Eighty-eight females underwent an interview to assess sociodemographic data, psychiatric comorbidities, level of pain, FM impact, clinical symptoms of anxiety, depression, insomnia, quality of life, and psychological trauma. Results: The majority of participants (71.5%) met the diagnostic criteria for current post-traumatic stress disorder (PTSD). Participants reported having suffered traumatic events throughout their lifespan, especially in childhood and early adolescence, in the form of emotional abuse, emotional neglect, sexual abuse, and physical abuse. Traumatic events predict both poor quality of life and a level of pain in adulthood. All patients showed clinically relevant levels of anxiety, depression, insomnia, suicidal thoughts, and pain, as well as somatic comorbidities and poor quality of life. Pain levels predicted anxiety, depression, dissociation, and insomnia symptoms. 84% of the sample suffered one or more traumatic events prior to the onset of pain. Conclusions: Our data highlight the clinical complexity of patients with FM and the role of childhood trauma in the onset and maintenance of FM, as well as the high comorbidity between anxiety, depression, somatic symptoms, and FM. Our data also supports FM patients experiencing further retraumatization as they age, with an extremely high prevalence of current PTSD in our sample. These findings underscore the need for multidisciplinary programs for FM patients to address their physical pain and their psychiatric and somatic conditions, pay special attention to the assessment of psychological trauma, and provide trauma-focused interventions. Trial registration: ClinicalTrials.gov NCT04476316. Registered on July 20th, 2020.

High incidence of PTSD diagnosis and trauma-related symptoms in a trauma exposed bipolar I and II sample.

Background: Post-traumatic stress disorder (PTSD) is an established comorbidity in Bipolar Disorder (BD), but little is known about the characteristics of psychological trauma beyond a PTSD diagnosis and differences in trauma symptoms between BD-I and BD-II. Objective: (1) To present characteristics of a trauma-exposed BD sample; (2) to investigate prevalence and trauma symptom profile across BD-I and BD-II; (3) to assess the impact of a lifetime PTSD diagnosis vs. a history of trauma on BD course; and (4) to research the impacts of sexual and physical abuse. Methods: This multi-center study comprised 79 adult participants with BD with a history of psychological trauma and reports baseline data from a trial registered in Clinical Trials (https://clinicaltrials.gov; ref: NCT02634372). Clinical variables were gathered through clinical interview, validated scales and a review of case notes. Results: The majority (80.8%) of our sample had experienced a relevant stressful life event prior to onset of BD, over half of our sample 51.9% had a lifetime diagnosis of PTSD according to the Clinician Administered PTSD scale. The mean Impact of Event Scale-Revised scores indicated high levels of trauma-related distress across the sample, including clinical symptoms in the PTSD group and subsyndromal symptoms in the non-PTSD group. Levels of dissociation were not higher than normative values for BD. A PTSD diagnosis (vs. a history of trauma) was associated with psychotic symptoms [2(1) = 5.404, p = 0.02] but not with other indicators of BD clinical severity. There was no significant difference between BD-I and BD-II in terms of lifetime PTSD diagnosis or trauma symptom profile. Sexual abuse significantly predicted rapid cycling [2(1) = 4.15, p = 0.042], while physical abuse was not significantly associated with any clinical indicator of severity. Conclusion: Trauma load in BD is marked with a lack of difference in trauma profile between BD-I and BD-II. Although PTSD and sexual abuse may have a negative impact on BD course, in many indicators of BD severity there is no significant difference between PTSD and subsyndromal trauma symptoms. Our results support further research to clarify the role of subsyndromic PTSD symptoms, and highlight the importance of screening for trauma in BD patients.

Intracranial self-stimulation recovers learning and memory capacity in basolateral amygdala-damaged rats.

We studied the capacity of post-training intracranial self-stimulation (SS) to reverse or ameliorate learning and memory impairments caused by amygdala damage in rats. A first experiment showed that lesions of the basolateral amygdala (BLA) slow down acquisition of two-way active avoidance conditioning (2wAA). In a second experiment we observed that a post-training SS treatment administered immediately after each 2wAA conditioning session is able to completely reverse the disruptive effects of the BLA lesions, and the facilitative effect lasts for 10days. A third experiment allowed us to differentiate the strong recuperative effects of the SS treatment from the slight effect caused by overtraining the same conditioning response. We concluded that SS is able to counteract the behavioral deficit induced by BLA damage, probably by activating alternative undamaged brain structures related to learning and memory, such as the hippocampus.

Cognitive Enhancement via Neuromodulation and Video Games: Synergistic Effects?

Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique able to modulate cortical excitability. This modulation may influence areas and networks responsible for specific cognitive processes, and the repetition of the induced temporary changes can produce long-lasting effects. TMS effectiveness may be enhanced when used in conjunction with cognitive training focused on specific cognitive functions. Playing video games can be an optimal cognitive training since it involves different cognitive components and high levels of engagement and motivation. The goal of this study is to assess the synergistic effects of TMS and video game training to enhance cognition, specifically, working memory and executive functions. We conducted a randomized 2 × 3 repeated measures (stimulation × time) study, randomly assigning 27 healthy volunteers to an active intermittent theta-burst stimulation or a sham stimulation group. Participants were assessed using a comprehensive neuropsychological battery before, immediately after, and 15 days after finishing the video game+TMS training. The training consisted of 10 sessions where participants played a 3D platform video game for 1.5 h. After each gaming session, TMS was applied over the right dorsolateral prefrontal cortex (DLPFC). All participants improved their video gaming performance, but we did not find a synergistic effect of stimulation and video game training. Neither had we found cognitive improvements related to the stimulation. We explored possible confounding variables such as age, gender, and early video gaming experience through linear regression. The early video gaming experience was related to improvements in working memory and inhibitory control. This result, although exploratory, highlights the influence of individual variables and previous experiences on brain plasticity.

General anesthesia in infants: neurobiological and neuropsychological concerns.

General anesthetics are crucial drugs for surgical interventions, which are indicated to induce analgesia, diminish pain, and reduce anxiety in order to facilitate invasive procedures. In pediatric patients, benefits of general anesthetics also include abolishment of motility. Besides their probed benefits on surgery, the recent warning of the Food and Drug Administration (FDA) on the use of general anesthetics in children yielded a controversy on their potential neurotoxic effects. In this review, the main facts of the cerebral development are studied, and the available evidence concerning the use of general anesthesia on the neuropsychological development of children is analyzed. Most of the studies found were uncontrolled retrospective cohorts for which conclusions are difficult to obtain. However, a few group of controlled studies, including the Mayo Anesthesia Safety in Kids study (MASK), have partially supported the FDA warning. Cumulated evidence appears to support the safety use of general anesthetics, but no conclusive data supporting that it may induce massive effects on the cognitive development of exposed children has been reported. Important evidence suggests that specific cognitive functions may result altered under long-term expositions. Such data must be considered for those involved in anesthetic procedures.

La anestesia general es una herramienta imprescindible para el proceso quirúrgico, ya que disminuye el dolor, reduce la ansiedad y genera inconsciencia. Sin ella, las cirugías serían dolorosas, riesgosas y emocionalmente traumáticas. La reciente emisión de una alerta sobre el uso de fármacos anestésicos en niños menores de 3 años por parte de la Food and Drug Administration (FDA) de los Estados Unidos generó controversia en torno a sus posibles efectos negativos. En este artículo se abordan los principales hitos del desarrollo neurobiológico del niño y se revisan las posibles consecuencias neuropsicológicas del uso de anestesia general en esta población. La mayoría de los reportes que abordan este tema son de tipo retrospectivo y arrojan resultados controversiales por sus inherentes dificultades metodológicas. Sin embargo, el estudio prospectivo sobre seguridad del uso de anestesia general en niños de la Clínica Mayo (MASK, Mayo Anesthesia Safety in Kids), junto con otros estudios a gran escala, han confirmado algunos datos obtenidos en los estudios experimentales que dieron sustento a la alerta emitida por la FDA. Así, las evidencias hasta ahora publicadas sugieren que el uso de anestesia general es seguro para el desarrollo cognitivo general del niño, aunque evidencian también alteraciones focalizadas en procesos cognitivos específicos que deben ser consideradas por el médico y la familia ante un procedimiento quirúrgico-anestésico.

Intracranial self-stimulation improves memory consolidation in rats with little training.

Post-training intracranial electrical self-stimulation can improve learning and memory consolidation in rats. However, the molecular mechanisms involved are not known yet. Since previous paradigms of this kind of facilitation are relatively unsuitable to try a molecular approach, here we develop a single and short model of learning and memory facilitation by post-training self-stimulation that could make easier the research of its neural and molecular basis. Thus, three consecutive experiments were carried out to ascertain whether post-training self-stimulation is able to facilitate memory when learning consists of only a brief (5 trials) two-way active avoidance conditioning session. The results of Experiment 1 showed that it is actually possible, and that 48 h after the acquisition session is a very good time to observe the memory improvement. As a way to probe the retroactive effect of self-stimulation, in Experiment 2 we observed that the same self-stimulation treatment given to the subjects not post-training but 48 h before a single two-way active avoidance session does not improve the acquisition of conditioning. In Experiment 3, we showed that the SS facilitative effect observed 48 h after the acquisition session in Experiment 1 was still maintained one week later. We concluded that post-training intracranial self-stimulation can consistently improve memory consolidation even when little acquisition training is given to the animals in a single training session.

Transcranial magnetic stimulation intervention in Alzheimer's disease: a research proposal for a randomized controlled trial.

OBJECTIVE: Alzheimer's disease is a major health problem in our society. To date, pharmacological treatments have obtained poor results and there is a growing interest in finding non-pharmacological interventions for this disease. Transcranial magnetic stimulation (TMS) is a non-invasive technique that is able to induce changes in brain activity and long-term modifications in impaired neural networks, becoming a promising clinical intervention. Our goal is to study the benefit of individualized TMS targeting based on the patient's functional connectivity (personalized targeting), and short duration TMS protocol, instead of current non-individualized and longer session approaches. A double blind randomized controlled trial will be conducted to assess the effects of TMS treatment immediately, 1 month, 3 months and 6 months after the end of the intervention. Fifty-four patients with a diagnosis of Alzheimer's disease will be randomly allocated into experimental (active TMS), sham control, or conventional intervention control group. We will quantify changes in cognitive, functional, and emotional deficits in Alzheimer patients, as well as the functional connectivity changes induced by the TMS treatment. RESULTS: We expect to demonstrate that personalized TMS intervention has a measurable positive impact in cognition, emotion, daily living activities and brain connectivity, thus representing a potential treatment for Alzheimer's disease. Trial registration The trial has been prospectively registered at ClinicalTrials.gov, identifier NCT03121066. Date of registration: 04/19/2017.

Intracranial self-stimulation after memory reactivation: immediate and late effects.

To assess whether intracranial self-stimulation (SS) given after memory reactivation could improve memory retrieval, we tested the immediate (Experiment 1) and late (24 h; Experiment 2) effects of an SS treatment on the retrieval of a two-way active avoidance conditioning in Wistar rats. Memory was reactivated 24 h after training and the reminder (Rm) used consisted of a 3 s exposure to the conditioned stimulus (a tone) in the same context as in the original learning. SS treatment (2500 trains at 100% of each rat's optimal intensity) was administered immediately afterwards. No significant differences between SS-treated and control groups were observed when the retrieval was tested immediately after the SS treatment with or without memory reactivation. However, retrieval was improved when tested 24 h after SS treatment alone or after the reminder exposure alone. The greatest improvement in avoidance was observed when both treatments were given together, that is, when the SS treatment was administered immediately after memory reactivation. Moreover, there were no significant statistical interactions between the effect of SS treatment and the ones of memory reactivation in any of both experiments. The present results show that the effect of an immediate SS treatment can be added to the ones of memory reactivation causing a strong long-term facilitation of memory retrieval.

Neural Basis of Video Gaming: A Systematic Review.

Background: Video gaming is an increasingly popular activity in contemporary society, especially among young people, and video games are increasing in popularity not only as a research tool but also as a field of study. Many studies have focused on the neural and behavioral effects of video games, providing a great deal of video game derived brain correlates in recent decades. There is a great amount of information, obtained through a myriad of methods, providing neural correlates of video games. Objectives: We aim to understand the relationship between the use of video games and their neural correlates, taking into account the whole variety of cognitive factors that they encompass. Methods: A systematic review was conducted using standardized search operators that included the presence of video games and neuro-imaging techniques or references to structural or functional brain changes. Separate categories were made for studies featuring Internet Gaming Disorder and studies focused on the violent content of video games. Results: A total of 116 articles were considered for the final selection. One hundred provided functional data and 22 measured structural brain changes. One-third of the studies covered video game addiction, and 14% focused on video game related violence. Conclusions: Despite the innate heterogeneity of the field of study, it has been possible to establish a series of links between the neural and cognitive aspects, particularly regarding attention, cognitive control, visuospatial skills, cognitive workload, and reward processing. However, many aspects could be improved. The lack of standardization in the different aspects of video game related research, such as the participants' characteristics, the features of each video game genre and the diverse study goals could contribute to discrepancies in many related studies.

Impact of Prefrontal Theta Burst Stimulation on Clinical Neuropsychological Tasks.

Theta burst stimulation (TBS) protocols hold high promise in neuropsychological rehabilitation. Nevertheless, their ability to either decrease (continuous, cTBS) or increase (intermittent, iTBS) cortical excitability in areas other than the primary motor cortex, and their consistency modulating human behaviors with clinically relevant tasks remain to be fully established. The behavioral effects of TBS over the dorsolateral prefrontal cortex (dlPFC) are particularly interesting given its involvement in working memory (WM) and executive functions (EF), often impaired following frontal brain damage. We aimed to explore the ability of cTBS and iTBS to modulate WM and EF in healthy individuals, assessed with clinical neuropsychological tests (Digits Backward, 3-back task, Stroop Test, and Tower of Hanoi). To this end, 36 participants were assessed using the four tests 1 week prior to stimulation and immediately following a single session of either cTBS, iTBS, or sham TBS, delivered to the left dlPFC. No significant differences were found across stimulation conditions in any of the clinical tasks. Nonetheless, in some of them, active stimulation induced significant pre/post performance modulations, which were not found for the sham condition. More specifically, sham stimulation yielded improvements in the 3-back task and the Color, Color-Word, and Interference Score of the Stroop Test, an effect likely caused by task practice. Both, iTBS and cTBS, produced improvements in Digits Backward and impairments in 3-back task accuracy. Moreover, iTBS increased Interference Score in the Stroop Test in spite of the improved word reading and impaired color naming, whereas cTBS decreased the time required to complete the Tower of Hanoi. Differing from TBS outcomes reported for cortico-spinal measures on the primary motor cortex, our analyses did not reveal any of the expected performance differences across stimulation protocols. However, if one considers independently pre/post differences for each individual outcome measure and task, either one or both of the active protocols appeared to modulate WM and EF. We critically discuss the value, potential explanations, and some plausible interpretations for this set of subtle impacts of left dlPFC TBS in humans.

Post-training intracranial self-stimulation facilitates a hippocampus-dependent task.

Previous research has shown that post-training intracranial self-stimulation facilitates implicit or procedural memory. To know whether it can also facilitate explicit memory, post-training intracranial self-stimulation was given to Wistar rats immediately after every daily session of a delayed spatial alternation task that seems to depend on the integrity of the hippocampal memory system. We tested the effects of intracranial self-stimulation in three consecutive learning phases which tried to make the task progressively more difficult: 10 s delay (D10 phase), 30 s delay (D30 phase), and inverting the starting position of the animals to make their response more dependent on allocentric cues (INV phase). Every phase finished when each rat achieved a fixed learning criterion. Intracranial self-stimulation facilitated the flexible expression of the learned response (INV phase). That is, when the starting position was randomly inverted, only the rats that received intracranial self-stimulation maintained the performance level acquired in the previous training phases. Changing the starting position reduced the correct performance of the non-treated subjects, which need more training sessions to achieve the learning criterion and made less correct responses than treated rats. These findings show that post-training intracranial self-stimulation can facilitate hippocampus-dependent memories.