Golnaz Baghdadi | AmirKabir University Of Technology (original) (raw)

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Videos by Golnaz Baghdadi

In this video, it was shown how you can use Graphpad prism to implement an unpaired t-test Key... more In this video, it was shown how you can use Graphpad prism to implement an unpaired t-test

Keywords: Graphpad prism; statistical analysis; t-test; non-parametric; unpaired; rank-sum; Wilcoxon matched-pairs signed-rank test

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Papers by Golnaz Baghdadi

Frontiers in Systems Neuroscience

Neurocognitive Mechanisms of Attention, 2021

2nd Basic and Clinical Neuroscience Congress, 2013

Sustained attention is the ability to keep your attention on a task over some time. It is a criti... more Sustained attention is the ability to keep your attention on a task over some time. It is a critical point in some important brain processes such as learning. In this abstract, we present a mathematical model to describe the interaction between bottom-up and top-down processes in sustained attention.
Bottom-up attention selects an object for attention based on its salient features. However, top-down attention usually selects a part of the environment for attention based on a predefined goal or previous knowledge. If bottom-up and top-down processes select different objects, sustained attention cannot be created, and the attention switches between these two selections. The principle hypothesis of our model is a control system to ignore one of the selections (bottom-up or top-down).
The proposed mathematical model has two blocks: 1- the controlled system so-called plant (both bottom-up and top-down attention that interact with each other to produce different kinds of attention), and 2- the controller (executive control that regulates the interaction). The plant is implemented by a two-dimensional differential equation whose parameters define the mentioned interaction. If there are both salience features and a predefined goal in the environment, the plant produces at least two basins of an attractor. One attractor is attributed to the bottom-up selection that can attract our attention to the salience feature and the other is related to the goal-based top-down selection. Therefore, our attention follows the trajectory that switches between these two basins. To neglect the distracting salience feature and attend to the goal, the controller changes the interaction parameters to remove the basin that is produced by bottom-up attention.
This model is capable to present other kinds of attention (e.g., divided attention) and also some behavioral symptoms of people with attention deficit disorder (ADD).

Frontiers in biomedical technologies, Aug 30, 2022

Neurocognitive Mechanisms of Attention, 2021

Neurocognitive Mechanisms of Attention, 2021

Neurocognitive Mechanisms of Attention

International Journal of Machine Learning and Cybernetics

Roughness recognition is an important function in the nervous system that facilitates our interac... more Roughness recognition is an important function in the nervous system that facilitates our interactions with the environment. Previous studies have focused on the neuro-cognitive aspects and frequency-based changes in response to the roughness stimuli. In this study, we investigate the effect of different roughness levels on the nonlinear characteristics of EEG signals. Nine healthy subjects participated in the current research and touched three surfaces with different levels of roughness in a passive dynamical way. The experiment was repeated for both hands separately. During the experiment, the EEG signals were recorded. Next, three nonlinear features were extracted using the recurrence quantification analysis (RQA) method; and four classifiers were hired to distinguish six conditions, including three levels of roughness and the touching hand. The results showed that EEG nonlinear characteristics were significantly affected by the variation of surface roughness. The effects were different between touching by the left or the right hand. Moreover, it was observed that employing the RQA-based features leads to the higher accuracy of classification compared to the conventional frequency-based features. Additionally, we found that the brain representation of tactile roughness has a pseudo-random dynamic, and the amount of roughness can influence a network of brain channels. Finally, utilizing the weighted combination of different brain channels while considering the extracted nonlinear features, the LDA classification accuracy was reached 93%. Therefore, it can be suggested that not only temporal variations of brain signals but also their spatial distribution (brain channels) are important to recognize the surface roughness.

Posture balance control is an essential ability that is affected by the attention load. We invest... more Posture balance control is an essential ability that is affected by the attention load. We investigated the effect of attention load on posture balance control experimentally and computationally. Fifteen young individuals participated in an experiment containing simultaneous performing of a balance control task and an auditory task. A previous computational model was extended by introducing the effect of attention load as a gain in a Proportional-Integral-Derivative (PID) controller. Results demonstrated that the sensitivity of the posture balance control to the attention load should be considered besides other influential factors in designing sport or physical rehabilitation exercises. Simulations suggested that the issues of joint impedance stiffness or viscosity might also be compensated by changing the attention load.

Attention deficit hyperactivity disorder (ADHD) is one of the neurodevelopmental disorder that is... more Attention deficit hyperactivity disorder (ADHD) is one of the neurodevelopmental disorder that is common in children. Most of the studies showed the impairment of visual attention in ADHD children. Little investigations have also addressed the difference in auditory attention in children with and without ADHD. In the current study, we investigated the difference between normal and ADHD children based on the performance in visual and auditory attention. Twelve normal and eight ADHD-inattentive-subtype children participated in our study. They did an integrated visual and auditory attention test. Mean and variability of the correct reaction times and the accuracy of response were recorded during the test. Results showed the performance decline (i.e., increasing mean and variability of reaction time and response error) of ADHD children with respect to the normal in auditory attention. According to the results, more attention to the auditory stimuli in diagnosis tools is suggested.

Trigeminal Neuralgia (TN) is an attacking, abrupt and electric-shock headache in the realm of one... more Trigeminal Neuralgia (TN) is an attacking, abrupt and electric-shock headache in the realm of one or two branches of trigeminal nerves. It is one of the most severe neuropathic pains ever known. By considering main known regions of the brain involved in TN, we made a conceptual model named TN pain neuro matrix. Then we took an external stimulation into account and assayed the different possible approaches about how it may be concluded to pain relief.

In this video, it was shown how you can use Graphpad prism to implement an unpaired t-test Key... more In this video, it was shown how you can use Graphpad prism to implement an unpaired t-test

Keywords: Graphpad prism; statistical analysis; t-test; non-parametric; unpaired; rank-sum; Wilcoxon matched-pairs signed-rank test

3 views

Frontiers in Systems Neuroscience

Neurocognitive Mechanisms of Attention, 2021

2nd Basic and Clinical Neuroscience Congress, 2013

Sustained attention is the ability to keep your attention on a task over some time. It is a criti... more Sustained attention is the ability to keep your attention on a task over some time. It is a critical point in some important brain processes such as learning. In this abstract, we present a mathematical model to describe the interaction between bottom-up and top-down processes in sustained attention.
Bottom-up attention selects an object for attention based on its salient features. However, top-down attention usually selects a part of the environment for attention based on a predefined goal or previous knowledge. If bottom-up and top-down processes select different objects, sustained attention cannot be created, and the attention switches between these two selections. The principle hypothesis of our model is a control system to ignore one of the selections (bottom-up or top-down).
The proposed mathematical model has two blocks: 1- the controlled system so-called plant (both bottom-up and top-down attention that interact with each other to produce different kinds of attention), and 2- the controller (executive control that regulates the interaction). The plant is implemented by a two-dimensional differential equation whose parameters define the mentioned interaction. If there are both salience features and a predefined goal in the environment, the plant produces at least two basins of an attractor. One attractor is attributed to the bottom-up selection that can attract our attention to the salience feature and the other is related to the goal-based top-down selection. Therefore, our attention follows the trajectory that switches between these two basins. To neglect the distracting salience feature and attend to the goal, the controller changes the interaction parameters to remove the basin that is produced by bottom-up attention.
This model is capable to present other kinds of attention (e.g., divided attention) and also some behavioral symptoms of people with attention deficit disorder (ADD).

Frontiers in biomedical technologies, Aug 30, 2022

Neurocognitive Mechanisms of Attention, 2021

Neurocognitive Mechanisms of Attention, 2021

Neurocognitive Mechanisms of Attention

International Journal of Machine Learning and Cybernetics

Roughness recognition is an important function in the nervous system that facilitates our interac... more Roughness recognition is an important function in the nervous system that facilitates our interactions with the environment. Previous studies have focused on the neuro-cognitive aspects and frequency-based changes in response to the roughness stimuli. In this study, we investigate the effect of different roughness levels on the nonlinear characteristics of EEG signals. Nine healthy subjects participated in the current research and touched three surfaces with different levels of roughness in a passive dynamical way. The experiment was repeated for both hands separately. During the experiment, the EEG signals were recorded. Next, three nonlinear features were extracted using the recurrence quantification analysis (RQA) method; and four classifiers were hired to distinguish six conditions, including three levels of roughness and the touching hand. The results showed that EEG nonlinear characteristics were significantly affected by the variation of surface roughness. The effects were different between touching by the left or the right hand. Moreover, it was observed that employing the RQA-based features leads to the higher accuracy of classification compared to the conventional frequency-based features. Additionally, we found that the brain representation of tactile roughness has a pseudo-random dynamic, and the amount of roughness can influence a network of brain channels. Finally, utilizing the weighted combination of different brain channels while considering the extracted nonlinear features, the LDA classification accuracy was reached 93%. Therefore, it can be suggested that not only temporal variations of brain signals but also their spatial distribution (brain channels) are important to recognize the surface roughness.

Posture balance control is an essential ability that is affected by the attention load. We invest... more Posture balance control is an essential ability that is affected by the attention load. We investigated the effect of attention load on posture balance control experimentally and computationally. Fifteen young individuals participated in an experiment containing simultaneous performing of a balance control task and an auditory task. A previous computational model was extended by introducing the effect of attention load as a gain in a Proportional-Integral-Derivative (PID) controller. Results demonstrated that the sensitivity of the posture balance control to the attention load should be considered besides other influential factors in designing sport or physical rehabilitation exercises. Simulations suggested that the issues of joint impedance stiffness or viscosity might also be compensated by changing the attention load.

Attention deficit hyperactivity disorder (ADHD) is one of the neurodevelopmental disorder that is... more Attention deficit hyperactivity disorder (ADHD) is one of the neurodevelopmental disorder that is common in children. Most of the studies showed the impairment of visual attention in ADHD children. Little investigations have also addressed the difference in auditory attention in children with and without ADHD. In the current study, we investigated the difference between normal and ADHD children based on the performance in visual and auditory attention. Twelve normal and eight ADHD-inattentive-subtype children participated in our study. They did an integrated visual and auditory attention test. Mean and variability of the correct reaction times and the accuracy of response were recorded during the test. Results showed the performance decline (i.e., increasing mean and variability of reaction time and response error) of ADHD children with respect to the normal in auditory attention. According to the results, more attention to the auditory stimuli in diagnosis tools is suggested.

Trigeminal Neuralgia (TN) is an attacking, abrupt and electric-shock headache in the realm of one... more Trigeminal Neuralgia (TN) is an attacking, abrupt and electric-shock headache in the realm of one or two branches of trigeminal nerves. It is one of the most severe neuropathic pains ever known. By considering main known regions of the brain involved in TN, we made a conceptual model named TN pain neuro matrix. Then we took an external stimulation into account and assayed the different possible approaches about how it may be concluded to pain relief.

2017 Artificial Intelligence and Signal Processing Conference (AISP), 2017

The predictive brain is a term that is known because of the capability of our neural system to fi... more The predictive brain is a term that is known because of the capability of our neural system to find a model of the environment and to use it for predicting the incoming stimulus. It has not been fully understood that how our neural system that consists of millions of oscillatory networks can create, update, and maintain a model for the sequential prediction. In the current paper, we have proposed an oscillatory network that its units connect to each other through synchronization mechanism. The network has been used to suggest a possible mechanism of extracting the regularities exist in a continuous performance test. The result of simulations has been compared with the recorded human experiment data. Outcomes showed that the proposed model can mimic the pattern of human behaviors. It can be concluded that brain may create and modified the model of the environment by updating the coupling weight or the level of synchronization between its different units. There are some parameters in ...

Brief overview of EEG (Electroencephalography) Brain Waves Terminologies Role of synchronization... more Brief overview of EEG (Electroencephalography)
Brain Waves
Terminologies
Role of synchronization and connectivity in the brain?
Why do we need to study synchronization and connectivity?
Role of Synchronization and Connectivity in Diagnosis
Connectivity and Synchronization Measures
Cross-frequency Coupling
ERD and ERS
Common software
Future works

BCI, 2021

This file is an introductory presentation of BCI systems

cognitive neuroscience, 2021

Some important points to define a study in cognitive neuroscience

COMPUTATIONAL PSYCHIATRY, 2021

An introduction to COMPUTATIONAL PSYCHIATRY

استفاده از ماوس و صفحه کلید های رایج برای افرادی که در اثر آسیب های مغزی-نخاعی و یا قطع عضو دارای... more استفاده از ماوس و صفحه کلید های رایج برای افرادی که در اثر آسیب های مغزی-نخاعی و یا قطع عضو دارای ناتوانی در ناحیه دستها هستند، امکان پذیر نمی باشد. در نتیجه این افراد از ارتباط با رایانه محروم هستند. در این پژوهش بر آن شدیم تا با استفاده از یک تکنیک مناسب در زمینه ردیابی حرکات، سیستمی را طراحی کنیم که به کمک حرکات چشم، امکان استفاده از رایانه به افراد معلول داده شود تا به این ترتیب از منزوی شدن این افراد جلوگیری کرده و به حضور آنها در جامعه کمک شود. علاوه بر توانبخشی به افراد معلول، استفاده از این سیستم برای افراد عادی نیز دارای جذابیت است و باعث افزایش میزان ارتباط بین کاربر و رایانه می شود. افزون بر دو مورد اشاره شده، امروزه از سیستم های ردیاب حرکات چشم در زمینه ارتباط بین بیمار و پرستار در بیمارستان ها، میزان و نحوه حرکت چشم برروی نقاط مختلف تصاویر تبلیغاتی ، حرکت ویلچر و ... استفاده می شود. در این طرح مرز بین عنبیه و صلبیه که لیمباس نامیده می شود، به کمک فرستنده و گیرنده های مادون قرمز ردیابی می شود. مقادیر اندازه گیری شده از موقعیت چشم به کمک یک نرم افزار مورد پردازش قرار گرفته و به مقادیر مناسب جهت حرکت مکان نما برروی صفحه نمایشگر، تبدیل می شوند. از آنجایی که تغییرات نور محیط، تغییر کاربر وحرکات ناخواسته سر می تواند روی عملکرد سیستم تاثیر بگذارد، در این نرم افزار یک مرحله کالیبراسیون نیز در نظر گرفته شده است تا سیستم بتواند برروی شرایط جدید تنظیم شود. در مرحله کالیبراسیون نرم افزار، کارایی الگوریتم های طبقه بندی کننده مختلفی از جمله شبکه های عصبی و الگوریتم K تا نزدیک ترین همسایه (KNN) مورد آزمون قرار گرفت. در نتیجه این آزمایش، الگوریتم طبقه بندی کننده KNN کارایی بهتری را از خود نشان داد و نرم افزار سیستم بر پایه آن طراحی گردید. در این نرم افزار محیط های مختلفی جهت تایپ حروف با حرکات چشم، اجرای بازی، محاسبات ریاضی ساده، اجرای فیلم و موسیقی و همچنین گزینه ای جهت کالیبراسیون مجدد سیستم تعبیه شده است. این نرم افزار به کاربر اجازه می دهد که تنها به کمک حرکات چشمش عملیات اشاره شده را اجرا نماید. حتی کالیبراسیون مجدد سیستم در حین کار نیز به کمک حرکات چشم قابل اجراست و بر خلاف بعضی از سیستم های خارجی موجود نیاز به کمک یک فرد دیگر جهت اجرای کالیبراسیون را ندارد. طراحی نرم افزار بر پایه الگوریتم های طبقه بندی کننده یک نوآوری در اینگونه سیستم ها به حساب می آید که باعث افزایش کارایی و بهبود عملکرد سیستم می شود. این سیستم برروی 10 فرد مختلف مورد آزمایش قرار گرفت، نتایج حاکی از آن است که با آموزش کاربر و طی یک دوره کار با سیستم، کاربر می تواند با سیستم ارتباط برقرار کرده و به راحتی از آن جهت کنترل و ارتباط با رایانه استفاده نماید. در مقايسه با دیگر سیستم های طراحی شده در داخل و خارج از کشور که بر اساس روشها و تکنیک های دیگری برای همین منظور طراحی شده اند می توان به مزایای قیمت بسیار پایین تر به علت استفاده از روش ردیابی اپتیکی (فتوالکتریک) حرکات چشم، سهولت استفاده، عدم تماس مستقیم سیستم با چشم و بدن کاربر، عدم نیاز به ردیابی حرکات سر و یا گردن (در بعضی از سیستم های مشابه از ردیابی حرکات سر و گردن استفاده شده است که در بعضی از آسیب های مغزی نخاعی فرد امکان حرکت گردن را ندارد)، بهبود عملکرد سیستم به علت استفاده الگوریتم طبقه بندی کننده در نرم افزار سیستم و اجرای مجدد مرحله کالیبراسیون سیستم به وسیله خود کاربر با حرکات چشم را اشاره نمود.

کلمات کلیدی: ردیابی حرکات چشم، روش فتوالکتریک، توانبخشی، الگوریتم طبقه بندی کننده

In the field of ophthalmology, vision researchers use eye tracking to study oculomotor behavior, ... more In the field of ophthalmology, vision researchers use eye tracking to study oculomotor behavior, cognitive visual function and vision deficiencies. Quantifiable eye-movement analysis enables new diagnostic markers and identification of disease at a much earlier stage of progression. Current methodologies that rely on observation can be automated, reducing variability. Therefore in this research it was tried to design a non-invasive eye tracker system which can be useful in the ophthalmology related research.
In our system, we have used Infrared photoelectric oculography (IR-Tracking) method that is contact-free, and can be used for a long time without any discomfort for the subject. The system works based on the principle of reflection of infrared light by the sharp boundary between iris and sclera, the limbus. The measured values of the eye position were processed by the system’s software which shows the result of processing numerically or graphically. As different factors such as changing the environment lights, or changing the user during the use and etc, can affect the performance of the system, a calibration stage was considered in the software in order to reduce such effects. The calibration stage takes the advantage of classification methods such as K-nearest neighborhood.
The system was tested on 10 subjects several times. The test subjects were asked to look at points in different directions and the system measured the direction of their gaze. The result shows that the designed system can track the eye movements and shows the gaze direction in different time graphically or as a numerical index.
In this research an eye tracker system was designed which is novel in our country because of the implemented tracking method and its calibration stage. This system that can track the eye movements in different directions can be useful in diagnosis of oculomotor disease. The other advantage of the system is that there is no necessity for the subject to sit in front of a monitor. The system can track the gaze direction even if the subject is lying down on the bed. Therefore the system can be used to investigate the performance of the eye movements after eye surgeries. The designed eye tracker can also be used as an appropriated tool in the study of cognitive visual function and vision deficiencies.

How we can use artificial intelligence in our research.

Advanced EEG signal processing workshop slides

Some of the feature selection or dimension reduction methods are introduced in this file.

در این فایل راهنمای مقدماتی از نحوه کار با جعبه ابزار EEGLAB آورده شده است

انتشارات دانشگاه صنعتی امیرکبیر, 2019

انشارات دانشگاه شاهد, 2021

نظریه آشوب شاخه‌ای از علوم ریاضی است که به دنبال عدم توجیه برخی از پدیده‌های طبیعی به کمک قوانین ... more نظریه آشوب شاخه‌ای از علوم ریاضی است که به دنبال عدم توجیه برخی از پدیده‌های طبیعی به کمک قوانین نیوتن با پیشرفت علم ارائه گردید و به‌تدریج توسعه چشمگیری پیدا کرد. تا کنون محققین توانسته‌اند بسیاری از رفتارها و پدیده‌های پیچیده¬ی مشاهده‌شده در حوزه‌های مختلفی از جمله زیست‌شناسی، علوم اعصاب، انسان‌شناسی، مکانیک، اقتصاد، بوم‌شناسی، جامعه‌شناسی، شیمی، فیزیک و کامپیوتر را به کمک مفاهیم مطرح در این نظریه توجیه کنند. این نظریه بر مطالعه، استخراج و کمّی سازی الگوهای منظم در رفتارهای به‌ظاهر تصادفی و بی‌نظم در انواعی از دینامیک‌های پیوسته و گسسته استوار است. اثر بال پروانه و حساسیت به شرایط اولیه از جمله معروف‌ترین اصول در علم و نظریه آشوب است که به چگونگی وقوع تغییرات و پیامدهای بسیار بزرگ در اثر تغییرات بسیار کوچک در سیستم‌های قطعی و غیرخطی اشاره دارند.
کتاب حاضر که به‌عنوان یک کتاب مرجع آموزشی به‌طور گام‌به‌گام مفاهیم و روش‌های مطرح در بررسی و تحلیل سیستم‌ها و دینامیک‌های غیرخطی پیوسته و گسسته را تشریح نموده است. در فصول آخر مباحث ارتباط آشوب و هندسه فرکتال‌ها، انواع آنتروپی و روش‌های محاسبه انواع بعد فرکتال و کمّی سازی سیگنال‌ها با ارائه مثال‌های کاربردی ارائه ‌شده است.

انتشارات جهاد دانشگاهی دانشگاه صنعتی امیرکبیر, 2021

چکیده مدل‌سازی و شبیه‌سازی از ابزارهای بسیار مهم در مهندسی سیستم‌ها بوده و جزء دروس اصلی در کلیه ... more چکیده
مدل‌سازی و شبیه‌سازی از ابزارهای بسیار مهم در مهندسی سیستم‌ها بوده و جزء دروس اصلی در کلیه رشته‌های مهندسی و علوم هستند. ابزار مدل‌سازی نه تنها به محققین كمك می‌کند كه درك بهتری از كاركرد سیستم‌ها و فرایندهای پیرامون خود داشته باشند، بلکه آن‌ها را قادر می‌سازد رفتار سیستم‌ها را پیش‌بینی کرده و آن‌ها را تحت شرایط مختلف تجزیه و تحلیل کنند.
مزیت‌های ذکر شده در مورد ابزار مدل‌سازی، در مورد سیستم‌های زیستی پر رنگ‌تر شده، در حدی که وجود آن را بسیار ضروری می‌سازد. زیرا سیستم‌های زیستی به‌خصوص بدن انسان با حساسیت‌های ویژه‌ای همراه هستند و در اکثر موارد جهت شناخت بیشتر، بررسی کارایی روش‌های تشخیصی و درمانی مختلف و یا کنترل عملکرد آن‌ها نمی‌توان بر روی آن‌ها آزمایش‌هایی را بر مبنای سعی و خطا انجام داد.
روش‌های متعددی برای مدل‌سازی سیستم‌ها و فرایندهای زیستی وجود دارد. لازم به ذکر است که این روش‌ها در مورد سیستم‌های غیر زیستی نیز قابل استفاده هستند. این روش‌ها را از یک جنبه می‌توان به مدل‌های محاسباتی و مدل‌های کیفی تقسیم‌بندی نمود و از جنبه دیگر می‌توان آن‌ها را به دو دسته مقدماتی نظیر روش‌های بر پایه تابع تبدیل، پاسخ ضربه، پاسخ پله و یا آنالیز طیف و پیشرفته مانند شبکه‌های عصبی، قوانین فازی و یا تئوری آشوب طبقه‌بندی نمود. در این کتاب تمرکز بر روی مدل‌های محاسباتی بر اساس روش‌های مقدماتی است و به روش‌های پیشرفته در مدل‌سازی پرداخته نمی‌شود.
این کتاب در دو بخش مباحث تئوری و مباحث کاربردی تنظیم شده است. در بخش اول در شش فصل، مباحث پایه و الگوریتم‌های مربوط به روش‌های مختلف شناسایی سیستم و مدل‌سازی ارائه شده است و سعی شده است به ارائه مثال‌های متنوع نحوه استفاده ازاین‌روش‌ها تفهیم شود. همچنین در این بخش با پیاده‌سازی مثال‌های ساده در محیط نرم‌افزار متلب، نحوه استفاده از این الگوریتم‌ها به‌صورت کاربردی ارائه شده است. فصول اصلی بخش اول کتاب شامل روش¬های مدل¬سازی تحلیلی، شناسایی سیستم به روش¬های پارامتریک و غیرپارامتریک، نکات مهم در ارزیابی مدل و همچنین روش باندگراف است.
در بخش دوم کتاب، در هفت فصل، به کاربردهای مختلف روش‌های مدل‌سازی مقدماتی در مورد سیستم‌های زیستی پرداخته شده است. در این فصل‌ها مثال‌های پیچیده‌تر با تنوع بیشتری آورده شده است تا به محققین یک دید پایه در مورد نحوه استفاده از روش‌های ارائه شده داده شود. در این بخش محتوا بر اساس سیستم¬های مختلف بدن انسان شامل سیستم¬های سلولی، حرکتی، قلب و عروق، تنفسی، انتقال مواد و فرایندهای شیمیایی، عصبی-شناختی و انواع بیماری¬ها تقسیم¬بندی شده است. در مورد این سیستم¬ها تاکنون مدل¬های بسیار زیاد و پیچیده¬ای ارائه شده است، لیکن در این بخش از کتاب سعی شده فقط به ارائه مثال¬های نسبتا ساده¬تر که در سطح مباحث تئوری ارائه شده در بخش اول هستند، پرداخته شود.
تلاش شده است مطالب این کتاب به‌خصوص در بخش اول که شامل پایه‌های تئوری مسئله است، زبان ساده و قابل درک داشته باشد تا برای مبتدیان در این زمینه انگیزه و توانمندی لازم ایجاد گردد. این کتاب را می‌توان به‌عنوان پیش‌نیاز جهت یادگیری راحت‌تر روش‌های مدل‌سازی پیشرفته در نظر گرفت و هدف اصلی آن ایجاد درک اساسی از اهمیت و کاربردهای مدل‌سازی به‌خصوص در سیستم‌های زیستی، توانایی به‌کارگیری و پیاده‌سازی انواع روش‌های مقدماتی مدل‌سازی و توانایی شبیه‌سازی و ارزیابی این مدل‌ها در خوانندگان است.
قابل توجه است که این کتاب می تواند به عنوان منبع اصلی درس "مدلسازی سیستم های بیولوژیکی" در نظر گرفته شود که یکی از دروس اصلی-اجباری مقطع تحصیلات تکمیلی رشته مهندسی پزشکی بوده و همچنین جزء دروس آزمون دکترای مهندسی پزشکی می باشد و اخیرا نیز از طرف دانشجویان کارشناسی ارشد رشته مکاترونیک مورد استقبال قرار گرفته است. شایان ذکر است که نویسنده اول کتاب بمدت 25 سال در دانشگاه صنعتی امیرکبیر این درس را تدریس نموده و سرفصل ها و محتوای کتاب کاملا منطبق با سیلابس مصوب (وزارت عتف) این درس تنظیم گردیده است.
کتاب¬های لاتین موجود به طور جامع به تمامی جنبه¬های مدل¬سازی به خصوص در مورد سیستم¬های زیستی نپرداخته¬اند و متاسفانه مرجع کاملی وجود ندارد که هر دوجنبه نظری و کاربردی را در این زمینه پوشش دهد. به این ترتیب، ازآنجایی‌که تاکنون مرجع جامع و مناسبی از مدل‌سازی سیستم‌های زیستی در زبان فارسی و لاتین وجود نداشته است، کتاب حاضر که نتیجه سال‌ها تدریس درس مدل‌سازی توسط نویسنده اول کتاب در دانشکده مهندسی پزشکی دانشگاه صنعتی امیرکبیر است، می‌تواند به‌عنوان یک منبع مناسب برای درس مدل‌سازی در رشته مهندسی پزشکی و همچنین دیگر رشته‌های مهندسی و علوم پایه که در حوزه مدل¬سازی به خصوص مدل¬سازی سیستم¬های زیستی در حال فعالیت هستند می¬تواند مفید واقع شود.
مخاطب اصلی این کتاب محققین و دانشجویان در مقاطع تحصیلات تکمیلی هستند ولی نظر به بیان ساده مطالب و ارائه مثال‌های متنوع، دانشجویان در مقطع کارشناسی نیز می‌توانند از آن در انجام پروژه‌ها و تحقیقات خود استفاده لازم را ببرند و امید بر آن بوده است که این کتاب بتواند وسیله‌ای باشد که راه ورود به این حوزه را برای دانشجویان در تمامی مقاطع و دیگر علاقه‌مندان هموارتر بنماید.

Elsevier, 2021

This book provides an overview of the concepts behind the human attention control system from neu... more This book provides an overview of the concepts behind the human attention control system from neuro-cognitive and computational points of view in three parts.
The first part contains four chapters. In the first chapter, different forms of attention are classified according to processing paths, clinical models, stimulus types, and appearance. This chapter provides a brief introduction and general overview of different kinds of attention and various terms related to the attention control system's characteristics. In the second chapter, the functional anatomy of attention is explained based on the most famous attentional networks and pathways. The neurotransmitters' role in the proper functioning of the attention control system is described following the electrophysiological observations reported in experimental studies on the attention system. The first and second chapters are useful for students and researchers who have just started studying this system. Students who are familiar with the cognitive neuroscience of attention can skip these two chapters. Memory and attention have a close relationship that is described in the third chapter. In this chapter, the strong dependency between memory and different types of attention is discussed. The fourth chapter shows how attention and motor control systems interact. In addition to researchers in neuroscience and engineering, this chapter can be attractive to researchers in sport sciences to design more efficient activities and tools.
The information provided in the first part is the basis of findings reported in the second part that includes four chapters. The fifth chapter is about potent factors, such as nutrition, that can affect the human attention control system's function. General information about these factors can be helpful for anyone who wants to increase attention span and concentration. In the sixth chapter, the most common diseases and disorders associated with attention deficit and specific features of each are described. One of the problems and challenges for students and researchers outside the fields of psychiatry and psychology is how they can evaluate and quantify the attention control system's performance. Several famous subjective and objective (behavioral or neurophysiological) assessment methods are introduced in the seventh chapter. In the eighth chapter, various medicinal, non-medicinal, alternative therapeutic and rehabilitation methods and technologies are explained. The explanations given for these diagnostic and therapeutic methods can also pave the way for developing new techniques.
The last part, which would be of most interest to people keen on modeling, emphasizes conceptual and computational models of attention. These models help scientists developing new diagnostic and therapeutic methods, and finding out more knowledge about the function of the attention control system. The last chapter of this part contains the description of a novel oscillatory computational model of the human attention control system proposed by the authors.

The 10th Basic and Clinical Neuroscience Congress (BCNC-2021), 2021

The 10th Basic and Clinical Neuroscience Congress (BCNC-2021), 2021

Background and Aim: Alzheimer's disease is the most common type of dementia, about one million pe... more Background and Aim: Alzheimer's disease is the most common type of dementia, about one million people suffer from Alzheimer's disease in Iran. According to the Alzheimer's Association report, three-quarters of people with dementia have not been diagnosed and therefore do not have access to supportive care. The development of assistive diagnosis techniques can help to decrease the number of undiagnosed cases. In recent years, scientists have considered using EEG-based assistive diagnosis systems, which are in-site, not expensive, and easy to access, and tried to increase the accuracy of these systems using optimum biomarkers. The most commonly used biomarkers are linear features such as power-based indices for AD detection. Nonlinear features have not received much attention in Alzheimer's diagnosis, while their strength has been shown in other EEG studies. In this study, we investigate the changes in linear and nonlinear EEG features in individuals with AD. We also compared the performance of these features in discriminating AD from healthy individuals. Methods: Power-based indices (power spectral density (PSD) of EEG bands and the PSD ratio of different EEG bands') as linear features and complexity-based indices (fuzzy entropy, spectral entropy, Higuchi fractal dimension, and scaling exponent) as nonlinear features were extracted from publicly available EEG signals recorded from twenty-four individuals (12 ADs and 12 healthy control (HC)). Wilcoxon rank-sum test was used to statistically evaluate the significant differences between EEG features in AD and HC groups, considering each extracted feature in different EEG channels. To differentiate ADs from HCs, both types of features were fed into a support vector machine (SVM) classifier with a Gaussian kernel. Results: Statistical analysis showed that PSD in the delta band is significantly lower in the ADs than in the HC subjects (P-value < 0.01). In contrast, PSD of the theta band is significantly increased in AD subjects, especially in frontal channels (P-value <0.05). PSD is meaningfully lower in higher frequency bands (alpha and beta) in the AD group compared to the HC individuals in most channels. Delta/theta, theta/alpha, and theta/beta were the power ratios which are significantly different in the two groups in most channels. Nonlinear features of EEG also change outstandingly in AD. Fuzzy entropy is significantly decreased in AD subjects compared to the HC group (P-value < 0.05) in all channels except for the frontal ones. The scaling exponent and Higuchi fractal dimension are also lower in AD subjects compared to the HC group (P-value < 0.01) in most channels. The mean differentiating accuracy was 82.09% (using one linear feature) and 81.35% (using one nonlinear feature) considering the test data. Conclusion: The results showed that both linear and nonlinear features have nearly equal capability to distinguish AD subjects with high accuracy. Although linear features are easier to calculate and provide information about the power of EEG bands in people with AD, nonlinear features provide information about the irregularity and complexity of brain dynamics in ADs. According to the statistical analysis of nonlinear features, it seems that irregularity and complexity of brain activity reduce in AD individuals compared to the HC group.