CORRELATION & CORRELATION & MODELLING OF EEG SIGNALSMODELLING OF EEG SIGNALS

A. Erol Fazlıoğlu A. Erol Fazlıoğlu

What is EEG?What is EEG?

• Electroencephalography (EEG) is a medical Electroencephalography (EEG) is a medical imaging technique that measures brain imaging technique that measures brain function by analyzing the scalp electrical function by analyzing the scalp electrical activity generated by brain structures. activity generated by brain structures.

• It is a completely noninvasive procedureIt is a completely noninvasive procedure..

• The small electrical signals detected by The small electrical signals detected by the scalp electrodes are amplified the scalp electrodes are amplified thousands of times, then displayed on thousands of times, then displayed on paper or stored to computer memory.paper or stored to computer memory.

• IIt is currently being widely used to t is currently being widely used to study the brain organization of study the brain organization of cognitive processes such as perception, cognitive processes such as perception, memory, attention, language, and memory, attention, language, and emotion in normal adults and children.emotion in normal adults and children.

• For this purpose, the most useful For this purpose, the most useful application of EEG recording is the ERP application of EEG recording is the ERP technique.technique.

How is EEG used?How is EEG used?

The ongoing EEGThe ongoing EEG

• ERPs (event-related potentials) are ERPs (event-related potentials) are small voltage fluctuations resulting small voltage fluctuations resulting from evoked neural activity. from evoked neural activity.

• The ERP reflects, with high temporal The ERP reflects, with high temporal resolution, the patterns of neuronal resolution, the patterns of neuronal activity evoked by a stimulusactivity evoked by a stimulus..

What are ERPs?What are ERPs?

• Due to their high temporal resolution, Due to their high temporal resolution, ERPs provide unique and important ERPs provide unique and important timing information about brain timing information about brain processing.processing.

• Mental operations, such as those Mental operations, such as those involved in perception, selective involved in perception, selective attention, language processing, and attention, language processing, and memory, proceed over time ranges in memory, proceed over time ranges in the order of tens of millisecondsthe order of tens of milliseconds

How are ERPs used?How are ERPs used?

Obtaining ERPs from the Obtaining ERPs from the ongoing EEGongoing EEG

EEG WAVES AS DEFINED BY EEG WAVES AS DEFINED BY FREQUENCYFREQUENCY

• ALPHA  ALPHA 

• BETA  BETA 

• THETA  THETA 

• DELTADELTA  

NUMERICAL BRAIN MODELLING OF THE NUMERICAL BRAIN MODELLING OF THE HUMAN EEGHUMAN EEG

• The work focuses on the The work focuses on the development of a mathematical development of a mathematical model of the critical physiological model of the critical physiological mechanisms that underlie the mechanisms that underlie the electrical signals measured on the electrical signals measured on the scalp. scalp.

Thank YouThank You

• Any Questions?Any Questions?

• Erol FazlıoğluErol Fazlıoğlu