Objective: Since the direct measurement of attention via brain signals is significantly effective in eliminating excessive interfaces and has special importance for researchers, this study investigated the relations between visual sustained attention and EVENT RELATED POTENTIALS (ERPs) using morphological features.Method: Continuous Performance Test (CPT) was used to measure sustained attention. Signals were recorded using 32-channel Walter device with 19-channel electrode cap. Extracted epochs which were time-locked to stimuli onset in each group were averaged to calculate the ERPs. Four hundred morphological features in ERPs of different electrodes were computed in 51 subjects and Pearson correlation was calculated between these features and the result of the CPT.Results: The P3 peak on target stimuli (X) was clearly observed in comparison with non-target stimuli. Calculated correlations indicated that thirty three of these features had significant relation with the level of sustained attention.Conclusion: Based on the oddball paradigm, the resulted qualitative findings were in line with previous research with regard to P3 production. Most characteristics with significant relation with results of CPT, were RELATED to the voltage of relative EVENT dependent POTENTIALS (correctly responded X relative to non-X). In general, CPT results showed appropriate relation with brain signal parameters in many areas, which could be used for the assessment of level of sustained attention.

Objectives: Risk-taking is a personality trait which plays a part in the occurrence of work-RELATED accidents. For this reason, people who are highly risk-taking whose decision might cause accident should not be employed in critical situations. The purpose of this survey was to design and verify the validity of the risk tolerance questionnaire, suitable for control room operators, through examining the EVENT RELATED potential (ERP). Methods: At first, the questions were selected from reliable scientific resources based on the conceptual model. The questions of the initial questionnaire were selected based on face validity, and then the questionnaire was filled out by 178 control room operators. At the next step, the best questions of the questionnaire were extracted using exploratory factor analysis (EFA). In terms of reliability, 42 individuals of the study group refilled in the questionnaire again after three months as a test-retest. The ERPs were assessed using electroencephalography along with Balloon Analogue Risk Task (BART). The correlation coefficient calculated between the ERPs, and risky behaviors, and questionnaire scores. Results: One factor and 13 questions were identified as the best questions regarding EFA. Cronbach's alpha was 0. 91. The Spearman correlation coefficient was calculated between the questionnaire score and risk-taking behavior as well as between the questionnaire score and P300, which was 0. 38 (P = 0. 01, η,2 = 0. 70) and 0. 63 (P = 0. 01, 2 η, = 0. 99), respectively. Conclusion: The Operator control Room Risk-Taking (ORTQ) questionnaire consists of 13 questions which can be used as an appropriate tool to assess the risk-taking trait in control room operators and also for research purposes. This questionnaire has got three personality dimensions including risk-taking nature, impulsivity and venturesomeness.

Introduction: Emotional stimulus is processed automatically in a bottom-up way or can be processed voluntarily in a top-down way. Imaging studies have indicated that bottom-up and top-down processing are mediated through different neural systems. However, temporal differentiation of top-down versus bottom-up processing of facial emotional expressions has remained to be clarified. The present study aimed to explore the time course of these processes as indexed by the emotion-specific P100 and late positive potential (LPP) EVENT-RELATED potential (ERP) components in a group of healthy women.Methods: Fourteen female students of Alzahra University, Tehran, Iran aged 18–30 years, voluntarily participated in the study. The subjects completed 2 overt and covert emotional tasks during ERP acquisition.Results: The results indicated that fearful expressions significantly produced greater P100 amplitude compared to other expressions. Moreover, the P100 findings showed an interaction between emotion and processing conditions. Further analysis indicated that within the overt condition, fearful expressions elicited more P100 amplitude compared to other emotional expressions. Also, overt conditions created significantly more LPP latencies and amplitudes compared to covert conditions.Conclusion: Based on the results, early perceptual processing of fearful face expressions is enhanced in top-down way compared to bottom-up way. It also suggests that P100 may reflect an attentional bias toward fearful emotions. However, no such differentiation was observed within later processing stages of face expressions, as indexed by the ERP LPP component, in a topdown versus bottom-up way. Overall, this study provides a basis for further exploring of bottomup and top-down processes underlying emotion and may be typically helpful for investigating the temporal characteristics associated with impaired emotional processing in psychiatric disorders.

Background: The P600 brain wave reflects syntactic processes in response to different first language (L1) syntactic violations, syntactic repair, structural reanalysis, and specific semantic components. Unlike semantic processing, aspects of the second language (L2) syntactic processing differ from the L1, particularly at lower levels of proficiency. At higher L2 proficiency, syntactic violations are more likely to result in P600, similar to the L1 native speakers. Objectives: This study aims to assess the effect of proficiency on L2 syntactic processing in late bilinguals and determine whether L1-like cerebral activation patterns will result. Materials & Methods: In this descriptive quantitative research, the subjects were two groups of Persian-English bilinguals (L1=Persian, L2=English; n=10 high-proficient, n=10 low-proficient; gender=female who started learning English as a Foreign Language (EFL) after the age of 15 through explicit instructions. Within the violation paradigm, EVENT-RELATED POTENTIALS (ERPs) were collected from the subjects in the neurocognitive lab of Shahid Beheshti University, Iran, in 201920. The experimental trials of the ERP task included violated English regular past tense verbs. ERP components were compared with those of the L1 (components closer to P600). Results: The t-value for P600 peak latency differed significantly only for the Incorrect past tense verb (ICV) condition and only in O2 (P=0. 039463, t=2. 2205, CI: 0. 003112-0. 11249, P<0. 05) between the two groups (higher in the high proficient group). Conclusion: P600 for the high-proficient group demonstrated that L2 proficiency was a more determinant factor in L1-like cortical representation of L2 than the age of acquisition and or the type of context.

Autism spectrum disorder is a developmental disorder that involves disorders in social interaction and communication and repetitive or stereotypical behavior. In some children with autism, the sensitivity to acoustic stimuli is much higher than normal (hypersensitive) versus in some other children, this sensitivity is less than normal (hyposensitive). In this study a method for evaluation of auditory system of hypersensitive and hyposensitive autism children using EVENT RELATED POTENTIALS (ERPs) was presented. The EEG signal was recorded from 10 autism children (2 girls) with average age of 7. 7 2. 31 years. In order to record ERPs, 2000 audio stimulation based on the MissMatch Negetivity (MMN) Pattern was presented to participants. These stimulus include 1600 standard sounds with a frequency of 1000 Hz, deviant at 1300 Hz, and noise at frequencies of 1500-1000, 500 and 2000 Hz. In order to analyze ERP data, 18 time domain features have been extracted from the ERP components in all three types of stimulation (standard, deviation, noise). Based on the results, in the deviant stimuli, total positive area of the Pz channel in the hypersensitive group was significantly increased (p=0. 028) compared to the hyposensetive group. Also, in the noise stimuli, total positive area in C4 and Pz channels has significantly increased (p=0. 028, p=0. 009) in the hyposensitive group compared to hypersensetive group. In conclusion, when hypersensitive children were exposed to deviant stimulue, neural activity was increased in parietal lobe, wheras in hyposensitive children neural activity increased in central and parietal lobe during noise stimulue. Therefore, this method can be useful in assessing children's autism spectrum in terms of hearing loss sensitivity.