Event related potentials
From Psy3242
Event Related Potentials
Event related potentials (ERP) also known as ‘evoked’ potentials (EP); is a Neuroscientific technique enabling the observation of human brain activity and its role in cognitive processing.
EEG
Electroenphalography (EEG) is a medical imaging technique used to measure brain functioning. EEG analyzes electrical activity in the scalp induced by structures of the brain. The ERP technique is a very useful application of EEG that is used to study how the brain’s organization of cognitive processes. ERP is an electrical signal averaging method which uses EEG scalp potentials specific to a certain time period specific to repeated external events. In other words, ERP involves taking the average amount of electrical signals from the scalp that occurred within a time period when an external stimulus was presented. The electrical signals are produced by the nervous system in response to a stimulus. Some controversy remains about the accuracy of ERP due to the difficulty to distinguish whether the electrical signals were a result of the external stimulus presented by the researcher or from another stimuli. However, background stimuli also known as ‘noise’ can be averaged out leaving an accurate estimate of ERP signals that are only associated with the processing of the presented stimulus. ERP is able to monitor how quickly nerve signals reach the brain as a response to a stimulus which aides in the learning of how different types of information is processed.
Clinical Evoked Potentials
Auditory, visual, and other sensory stimuli are used in clinical evoked potential studies. Visual evoked potential (VEP) involves the stimulation of vision. For example, a patient may sit in front of a screen while alternating patterns are shown. Auditory evoked potential (AEP) involves the presentation of sound. For example, a patient may listen to a series of clicks in their ear. Sensory evoked potential is when short electrical impulses are administered on an arm or leg. ERPs provide documentation of brain activity down to milliseconds providing a specific measurement of amount of time involved in neural activation during different tasks. .
