Merge pull request #80 from RupJyotiUX/main

Updated banner image, course images, and minor tweaks

Author: lorforlinux

courses/basics-of-neuroscience/media/axial-resistance.png

@@ -31,10 +31,11 @@ Membrane resistance refers to resistance to the flow of ions across the neuronal
 - Ion Channels: The presence and density of ion channels directly affect membrane resistance. More channels result in lower resistance because they provide additional pathways for ions to flow.
 - Membrane Composition: The lipid bilayer structure and the types of proteins embedded in the membrane influence its overall resistance. A thicker membrane will have higher resistance.
 
-.. todo:: Add Membrane Resistance (Rm) graphic here.
-
 .. note:: A high membrane resistance helps maintain the membrane's resting potential by minimizing the flow of ions across it. 
 
+.. figure:: ../media/membrane-resistance.*
+   :alt: Membrane Resistance
+
 2. Axial Resistance (Ri)
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -45,7 +46,8 @@ Axial resistance refers to resistance to the flow of electrical current along th
 - Cytoplasmic Conductivity: The concentration of ions and other conductive materials in the cytoplasm affects axial resistance. A higher concentration of conductive ions leads to low axial resistance.
 - Diameter of the Neuron: Larger diameter axons have lower axial resistance because a greater cross-sectional area allows for easier ion flow. This is why larger axons can conduct signals more rapidly.
 
-.. todo:: Add Axial Resistance (Ri) graphic here
+.. figure:: ../media/axial-resistance.*
+   :alt: Axial Resistance
 
 .. note:: Axial resistance affects how far a signal can travel along an axon without significant potential loss. Lower axial resistance allows signals to travel farther and faster.
 
@@ -57,6 +59,7 @@ Axial resistance refers to resistance to the flow of electrical current along th
 
 .. todo:: ADD CONDUCTANCE FORMULA
 
+
 4.1.2 Capacitance:
 ==================
 

courses/basics-of-neuroscience/media/membrane-resistance.png

@@ -24,14 +24,16 @@ Voltage-gated channels are specialized membrane proteins that open or close in r
 allow neurons to transmit signals rapidly and effectively throughout the nervous system. The action potential arises from the activity of two primary voltage-gated ion 
 channels: voltage-gated Na⁺ channels and K⁺ channels. These channels open and close at specific moments, generating ion flow, which leads to an action potential. 
 
-.. todo:: Add voltage-gated channel diagram here .  
+.. figure:: ../media/voltage-gated-on-Ion-channels.*
+   :alt: voltage-gated-on-Ion-channels
 
 .. note:: Voltage gated ion channels open when the neuron’s membrane potential reaches a certain value called threshold value. [1]_
 
 5.2 Phases of the Action Potential 
 ***********************************
 
-.. todo:: Add phases of action potential diagram here.
+.. figure:: ../media/phases-of-the-action-potential.*
+   :alt: phases-of-the-action-potential
 
 The action potential consists of several distinct phases, each characterized by specific changes in membrane potential and ion movement : 
 
@@ -102,6 +104,10 @@ to fire another action potential, or requires a stronger-than-normal stimulus to
 action potentials propagate in one direction (without reversing course) and that the cell has enough time to 
 reset its membrane potential to its resting state.
 
+.. figure:: ../media/refractory-period.*
+   :alt: Refractory Period
+
+
 Types of Refractory Periods
 ----------------------------
 
@@ -142,6 +148,8 @@ Myelination : [1]_
 
 **Nodes of Ranvier:** Action potentials jump between nodes of Ranvier (gaps in the myelin sheath) through a process known as saltatory conduction. This significantly speeds up the transmission of impulses compared to continuous conduction in unmyelinated axons.
 
+.. figure:: ../media/myelination.* 
+   :alt: Myelination
 
 Diameter of Axon : [1]_
 ~~~~~~~~~~~~~~~~~~~~~~~~

courses/basics-of-neuroscience/media/myelination.png

@@ -453,6 +453,27 @@ We have 2 options to measure the EEG signals, either using the gel electrodes or
 
 .. note:: Similarly you can use the band to record EEG signals from the visual cortex part of brain by placing the dry electrodes on O1 and O2 instead of Fp1 and Fp2. Everything else will remain the same.
 
+2-Channel EEG data 
+----------------------
+
+To record 2-channel Electroencephalography (EEG) data using two BioAmp EXG Pills in conjunction with an Arduino Uno R4 Minima, meticulous hardware setup is essential.
+
+**Required Components**
+
+1. Two BioAmp EXG Pill
+2. Arduino Uno R4 minima
+3. Breadboard
+4. Jumper wires
+5. Gel electrodes
+
+**Hardware setup**
+
+To set up the hardware for 2-channel EEG recording using two BioAmp EXG Pill modules and an Arduino Uno R4 Minima, begun by connecting the Arduino's 5V and GND pins to the power rails of a breadboard, then supply VCC and GND from the breadboard to both BioAmp EXG Pills. Connect the OUT pin of the first EXG pill to Arduino's analog pin A0 (channel 1) and the second EXG Pill's OUT to anolog pin A1 (channel 2). For electrodes placement, connect the IN+ of each module (red wires) to different EEG recording sites on the forehead (eg. Fp1 and Fp2), and connect IN- (black wires) and both REF pins (yellow wires) from the EXG Pills to a common reference electrode placed on a neutral location like the mastoid or earlobe to ensure clean and synchonized signal acquisition.
+
+.. figure:: media/channel-2-eeg-connection.*
+    :align: center
+    :alt: 2 Channel EEG Connection
+
 Uploading the code
 -----------------------
 
@@ -521,6 +542,7 @@ be used for a wide variety of interesting biosensing projects, including:
 - Blink detection (EOG)
 - Capturing photos with a blink of an eye (EOG) and many more examples. 
 
+
 Project ideas & tutorials
 ********************************