Mashtishk Vigyan Anusandhan

Abnormal slowing of the alpha rhythm refers to deviations from the typical frequency range and characteristics of the alpha waves observed in EEG recordings.  1.      Characteristics : o   Abnormal slowing of the alpha rhythm is characterized by a decrease in frequency, typically falling below the normal range of 8-13 Hz. o    The alpha rhythm may exhibit frequencies in the range of 6-8 Hz, indicating a slower oscillation pattern compared to the typical alpha activity. 2.    Appearance : o    The abnormal slowing of the alpha rhythm may manifest as extended anterior distribution of the alpha waves. o    In some cases, abnormal slowing may occur without other accompanying signs of drowsiness, distinguishing it from the normal alpha rhythm in drowsiness. 3.    Diagnostic Considerations : o    Identifying abnormal slowing of the alpha rhythm requires comparison with age-appropriate norms and considera...

Transcranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulation technique that involves applying a low-intensity electrical current to the scalp to modulate brain activity. Here is an overview of tDCS: 1.       Principle : o tDCS works by delivering a constant, low-level electrical current (typically between 1-2 milliamps) through electrodes placed on the scalp. o   The current flows from anode (positive electrode) to cathode (negative electrode), modulating the resting membrane potential of neurons in the underlying brain regions. 2.      Effects : o   Anodal Stimulation : Anodal tDCS is thought to depolarize neurons, increasing their excitability and promoting cortical activity in the targeted brain area. o   Cathodal Stimulation : Cathodal tDCS is believed to hyperpolarize neurons, reducing their excitability and inhibiting cortical activity in the targeted brain region. 3.    ...

White matter (WM) is one of the two main types of tissue in the brain, along with gray matter. Here is an overview of white matter in the brain: 1.       Composition : o White matter consists primarily of myelinated nerve fibers, which are long extensions of nerve cells (neurons) that form connections between different brain regions. o   The white appearance of this tissue is due to the high concentration of myelin, a fatty substance that insulates and protects the nerve fibers, facilitating the rapid transmission of electrical signals between neurons. 2.      Function : o White matter plays a crucial role in facilitating communication between different regions of the brain by transmitting electrical impulses along the nerve fibers. o It forms the neural pathways that connect various brain areas, allowing for coordinated functioning of different brain regions involved in sensory processing, motor control, cognition, and other functions. ...

A Volume Conduction Model (VCM) is a computational model used in the field of neurostimulation, particularly in techniques like Transcranial Magnetic Stimulation (TMS) and Transcranial Current Stimulation (TCS). Here is an overview of Volume Conduction Modeling: 1.       Purpose : o VCMs are designed to simulate the flow of electrical currents through different tissues in the head, including the scalp, skull, cerebrospinal fluid, and brain. These models help researchers and clinicians understand how electrical fields generated by external stimulations propagate and interact with neural tissue. 2.      Construction : o A VCM typically divides the head into different compartments representing various tissues with distinct electrical properties, such as conductivity and permittivity. Common compartments include skin, skull, cerebrospinal fluid, gray matter, and white matter. o Geometrically accurate boundaries between tissue compartments are def...