سمیه حیثیت طلب

Social hierarchy influences behavior across species, including humans, and its formation depends on cognition, social memory, and reinforcement learning processes. The ability to learn from feedback is essential for successful interactions within social environments. Differences in social dominance can significantly impact various aspects of cognition and behavior. The present study aimed to compare the behavioral performance of individuals with high and low social dominance in learning from positive and negative feedback.

An initial sample of 186 individuals completed the State-Trait Anxiety Inventory and the dominance subscale of the Jackson Personality Inventory online. Based on these assessments, 34 individuals were purposively selected, with 19 assigned to the high social dominance group and 15 to the low social dominance group. Both groups completed a probabilistic learning task individually. Behavioral data were analyzed using mixed ANOVA.

No significant differences were observed between the high and low social dominance groups in reaction time or response accuracy when learning from positive and negative feedback (p > 0.05). However, in both groups, response accuracy was significantly higher when learning from negative feedback compared to positive feedback (p < 0.05).

The findings suggest that negative feedback enhances response accuracy in both high and low social dominance groups. This highlights the role of negative reinforcement in guiding learning and decision-making across different levels of social dominance.

Amblyopia is a visual impairment, often unilateral, caused by a developmental disorder that can be associated with cognitive deficits, including attention disorders. This study aimed to investigate the effectiveness of transcranial direct current stimulation (tDCS) in improving the attention network in adults with amblyopia.

This quasi-experimental study employed a pretest-posttest design with a sham-controlled group. The study population included adults aged 20 to 35 with amblyopia who were referred to optometry clinics in Meshginshahr in 1402. Using purposive sampling, 30 individuals were selected and randomly assigned to either the tDCS group (n = 15) or the sham group (n = 15). The experimental group received 10 sessions of 20-minute tDCS applied to the dorsolateral prefrontal cortex (three sessions per week), while the sham group received placebo stimulation. To assess attentional function, the Attention Network Test was administered before and immediately after the intervention.

The findings demonstrated that tDCS significantly improved the attention network in adults with amblyopia, indicating its effectiveness in enhancing attentional processing.

Our results suggest that tDCS, by directly modulating the attention network, may serve as an adjunct therapy to enhance the effectiveness of amblyopia treatment in adults.

Considering the increasing need for finding diagnostic criteria to help reliably predict Alzheimer's disease (AD) and given that neuropathological changes occur in brain areas, especially temporal areas, before the onset of AD clinical symptoms, and there is a functional relationship between these regions and the cognitive functions including spatial working memory (SWM), pattern recognition memory (PRM), and paired associates learning (PAL), this study aims to investigate these three functions in the children of parents with AD and healthy parents.

This is a comparative study. The statistical population consists of the children of parents aged 30-55 years referred to a neurology clinic in Tehran, Iran, in 2022. Of these, 55 children were selected using a convenience sampling method; 31 were the children of AD parents and 24 were the children of healthy parents. They were evaluated using three tests from the Cambridge neuropsychological test automated battery (CANTAB), including SWM, PRM, and PAL. The data were analyzed in SPSS software using independent t-test and Mann-Whitney U test.

Regarding the SWM performance, there were significant differences in the items of between errors (control group: 14.21±12.21; AD group: 34.58±22.69) and total errors (control group: 12.96±9.3; AD group: 37.03±22.22) between the two groups (P<0.01). Regarding the PRM performance, there were significant differences between the two groups in two items of mean latency (control group: 1917.17±364.03; AD group: 2186.94±445.15, P=0.020) and percent correct (control group: 96.33±4.44; AD group: 84.39±8.93; P=0.001). There were no significant differences in the mean correct and incorrect latencies in the PRM test (P>0.05). Regarding the PAL performance, there were significant differences in all three items of first trial memory score (control group: 23.08±1.59; AD group: 17.65±4.32), mean errors to success (control group: 0.54±0.36; AD group: 2.31±1.83), and total errors (control group: 4.54±2.87; AD group: 17.10±1.83) between the two groups (P<0.01).

The PAL, PRM, and SWM of the children of AD and non-AD parents are different which may be considered as the indicators of AD.

Learning disorder is a neurodevelopmental disorder that leads to difficulties in learning and performance of reading, writing, and mathematics. Transcranial electrical stimulation is one of the recent interventions that has been used in this group. The current paper aimed to systematically combine the findings of the existing studies to find the effectiveness of these brain stimulation interventions in improving the executive functions and mathematical performance of individuals with learning disorders, as well as the possible moderating variables using the meta-analysis method.  

The statistical population of the research was all published studies including scientific articles and theses. The systematic literature turned 21 studies in the meta-analysis, and 64 effect size Cohen’s ds were extracted and analyzed using CMA3 software.

The findings showed a significant moderate combined effect size in both fixed and random effects models. Moreover, the effect size of the transcranial random noise stimulation was shown to be larger than the transcranial direct-current stimulation and transcranial alternating current stimulation. In addition, the meta-regression showed that age is a significant predictor and moderator with a better effectiveness in younger individuals.

These findings reveal that transcranial electrical stimulation, especially random noise method, as one of the effective interventions in improving the executive functions and mathematical performance of children with learning disorder.

The present study aims to investigate the effects of repeated transcranial magnetic stimulation (rTMS) on the cognitive functioning of policemen with post-traumatic stress disorder (PTSD). 

This is a quasi-experimental study with a pre-test/post-test design. The study population included all male police officers referred to the neuropsychiatric department of Imam Sajjad Hospital in Tehran, Iran, in 2022. Of these, 30 policemen diagnosed with PTSD were selected using a convenience sampling method and randomly divided into two groups of control and intervention. Their PTSD was diagnosed using a diagnostic interview by a psychiatrist and an expert clinical psychologist. Cognitive functions were evaluated using Rey’s visual memory test (VMT), Rey’s auditory-verbal learning test (AVLT), Tower of London test (TLT), Stroop test, and Wisconsin card sorting test, which were performed at the pre-test and post-test phases for both groups. The intervention group received 20-Hz rTMS at 10 sessions, including 5 seconds of stimulation and 20 seconds of rest interval between each stimulation (1000 pulses per session). The data were analyzed by multivariate analysis of covariance in SPSS software, version 22.

The intervention group showed better scores in the VMT, AVLT, TLT, residual error, number of card designs, interference score, interference time, congruent error, and incongruent  error compared to the control group

The high-frequency rTMS has a positive effect on the cognitive functions of policemen suffering from PTSD.

Glial cells release different gliotransmitters and response to neurotransmitters released from neurons. These cells especially astrocytes, having different transporters, play an important role in synaptic space homeostasis and synaptic plasticity. In this study, the role of hippocampal glial glutamate transporter (EAAT2) in baseline synaptic response and short term synaptic plasticity were investigated.

In this experimental study, ceftriaxone, EAAT2 activator (0.5mmol/0.5μl), was microinjected intrahippcampally for activation of hippocampal glial glutamate transporter in male wistar rats. Baseline synaptic response and short term synaptic plasticity were evaluated by field potential recording. fEPSP was recorded from CA1 following Schaffer collaterals stimulation. After Input/Output curve construction, short term synaptic plasticity was induced by paired pulse stimulations.

Activation of EAAT2 by ceftriaxone microinjection in CA1 did not have any effect on baseline synaptic response (P> 0.05, Two Way ANOVA). There was no significant difference in Paired Pulse Index at 20, 80, and 200 ms inter-pulse interval between ceftriaxone treated and control group (P> 0.05, Two Way ANOVA).

The results suggest that hippocampal glial glutamate transporter activation does not have effect on baseline synaptic response and short term synaptic plasticity in CA1 area of the hippocampus.

Considering the role of glial cells in regulating the excitability of the nervous system as well as synaptic plasticity, correcting these features of the nervous system by manipulating glial cells can help the treatment or prevention of neurological diseases. In this study, the role of glial cells in the homeostasis of the glutamate in the synaptic space of the hippocampus was evaluated, through the stimulation of its uptake, on the basic synaptic activity and short-term synaptic plasticity.

Astrocytic connexins (Cxs) play roles in ion diffusion to the extracellular milieu and in release of ATP and gliotransmitters including glutamate. Connexin 43 (Cx43) is one of the most abundant Cxs in brain tissue, especially in the hippocampus, so, we investigated its role on CA1 baseline synaptic response and short term synaptic plasticity.

In this experimental study, bilateral intrahippocampal microinjection of TAT-Gap19, Cx43 blocker (1nmol/1μl) was performed for inhibition of hippocampal astrocytic connexin 43. Baseline synaptic response and short term synaptic plasticity were evaluated by field potential recording.

 According to two-way ANOVA, inhibition of hippocampal Cx43 did not have any effect on baseline synaptic response (P>0.05). TAT-Gap19 decreased paired pulse index (PPI) at 20 and 80 ms inter pulse intervals (IPI, Unpaired t-test, P<0.05), but it did not affect PPI at 200 ms IPI (P>0.05).

The results suggest that the function of hippocampal astrocytic Cx43 does not affect baseline synaptic response but affects short term synaptic plasticity in CA1 area of the hippocampus.

Electroencephalography refers to the measurement of electrical changes in the brain that indicate spikes, transient currents, random events, and rhythms. Neurotherapy uses brain anatomy, psychological tests, behavioral measurements, and records the patterns of specific brain activities, with a focus on the rhythms and activities of delta, theta, alpha, beta, and gamma frequency bands as well as sensorimotor rhythms. The synchronous and asynchronous pattern of these frequency bands describes specific cognitive and behavioral states of an individual. Therefore, cortical involvement can be identified by measuring the combination of slow and fast rhythms in different parts of the head. Although EEG has a high temporal resolution, it cannot be used as a single imaging technique to study brain function due to the poor spatial resolution. In recent years, several non-invasive high-resolution spatial brain imaging techniques, including Positron Emission Tomography, Computed Tomography, and Functional Magnetic Resonance Imaging have developed to enhance understanding of the function of the human brain. Despite the desirable spatial resolution, these methods have an unfavorable temporal resolution. Therefore, to better understanding the brain function and studying deeper structures of the brain, EEG can be combined with any of these imaging methods. On the other hand, the analyzae of the frequency of EEG signals by identifying abnormalities in the neuronal function of the brain allows the integration with magnetic stimulation of the brain and neurofeedback for cognitive and behavioral enhancement. In this study, we introduce EEG and integrate it with non-invasive methods to identify the relationship between brain structures and abnormal patterns of neural activity, as well as improving the cognitive-behavioral function due to EEG neuroprocessing interventions.

Recently, research has been conducted on the use of social networks as a new platform for identifying people with mental disorders. In addition, because of the complexity of diagnosing psychological diseases using conventional methods, the use of machine learning for identifying theses psychological diseases is increasing. The goal of this article was to systematically review the research conducted using social media data for predicting and diagnosing psychological disorders with the help of machine learning. Based on systematic review on the Prisma method, the aim of this article was achieved through searching the main keywords of diagnosis and the prediction of mental disorders combined with machine learning and social media data without considering the dates of their publications. Depression had the highest frequency among the final 20 selected articles with a predictive power of 42% and 87%, the lowest and the highest respectively. On the other hand, only 30% of studies used questionnaires for gathering data on social media and the most common approach for data collection was public posts on social media by the use of regular expressions. Twitter has also been used as the largest source of data collection in these sorts of studies. It seems that computational psychology based on machine learning methods could help to identify disorders at an appropriate time and select more effective treatments for mental disorders among the users of social media.

The perinatal effects of antidepressants on the central nervous system (CNS) due to its common usage are important issues in neuroscience researches. Bupropion is an atypical antidepressant that is widely used for smoking cessation. The study of synaptic effects of bupropion can reveal its mechanism for nicotine dependence cessation. In this study the effects of long term administration bupropion during perinatal period on synaptic plasticity (Long Term Potentiating or LTP) in neonatal hippocampus slices were evaluated. Hippocampus slices from 19-25 day old rat pups by using standard brain slices techniques were prepared. Slices preparation were accomplished from three groups, control, normal saline and bupropion-treated (40 mg/Kg, i.p) according to maternal perinatal treatments. To produce LTP, the PB stimulation paradigm was applied and evoked responses were recorded from strata pyramidal of area CA1 following stimulation of Schaffer collaterals. Analysis of data showed that LTP induction parameter (PS amplitude) between normal saline and control groups had no significant difference, however there were significant difference between control and treated groups p<0.05, as well as normal saline and treated groups p <0.01. Long term perinatal administration of bupropion decreased induction and maintenance of LTP in strata pyramidal of area CA1. It seems that the loss of LTP maintenance in bupropion-treated animals is more likely the result of the disruption of cellular processes that they contribute following LTP induction.

The perinatal effects of antidepressants on CNS due to its common usage are important issues in neuroscience research. Bupropion is an atypical antidepressant that is used in smoke cessation under FDA approve widely. The study of synaptic effects of bupropion can reveal its mechanism for nicotine dependence cessation. In this study the long term effects of perinatal bupropion on population spike (PS) amplitudes were investigated. The PS amplitude is a good parameter for synaptic plasticity.

Hippocampal slices from 18-25 day old rat’s pups were prepared. The exam groups included control and Bupropion treated groups. Bupropion (40 mg/Kg, i.p) was applied in perinatal period daily as pretreatment. Bupropion also was perfused in ACSF (10, 50, 200 μ mol, 30 minutes) and tested for PS amplitude. PS amplitude of Stratum Radiatum was measured before and after Bupropion perfusion. Amplitude of PS before Bupropion perfusion was fitted as 100% for baseline.

A concentration of 10 μM did not reduce PS amplitude and Bupropion had no significant effects on PS amplitude. Bupropion in concentration of 50μM could reduce the amplitude of responses in 50% of cases. The 200 μM of Bupropion perfusion reduced population spike amplitude all slices (n=22). In the last state population spike amplitude in 8 out 0f 22 slices completely abolished. Decrease population spike amplitude in non-treated slices with 200 μM perfusion was more than treated slices.

Analyzing of data showed that chronic perinatal exposure to Bupropion in concentrations 50,200 µM reduced PS amplitude and we found adaptation synaptic in perfusion 200 µM compare with Bupropion treated slices with non- treated.

Antidepressants are very common therapeutic agents in medicine. Design and using new antidepressants have built a new scope for depression treatment. Bupropion is an atypical antidepressant but it is used as an anti-smoke agent widely due to its smoke cessation. Its effectiveness in producing smoking cessation seems independent of its antidepressant effects. The study of synaptic effects of bupropion can reveal its mechanism for nicotine dependence cessation. This study has tested the effects of bupropion on evoked responses of rat hippocampal slices. 16 hippocampal slices from 18-25 old age rat pops were tested. The hippocampal slices have been prepared according to standard techniques. Bupropion was perfused in ACSF (2 mmol) for 30 minutes. The amplitude of population spikes (PS) amplitude of Stratum Radiatum was measured before and after bupropion perfusion. Amplitude of PS before bupropion perfusion fitted as 100% for baseline. Bupropion (2 mmol) abolished PS of all slices for different periods. PS disappeared in 37.5% of slices for 1 hour, 25% for 1.5 hour, 12.5 % for 2 hour, and 25% for 4 hour or more. Bupropion disappeared PS 5-15 minutes after perfusion. Bupropion abolished or decreased PS amplitude. The results have showed that bupropion can decreases LTP or synaptic plasticity and alters the synaptic behavior in drug dependence.