fMRI can only measure blood flow in the brain, it cannot tell us the exact activity of individual neurons and so it can be difficult to tell what kind of brain activity is being represented on the screen. Electroencephalogram (EEG) EEGs measure electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap. The scan recording represents the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity. The main 4 of EEG waves are alpha, beta, theta and delta. Scientists can also measure activity through amplitude and frequency. Amplitude is the intensity or size of activity, frequency is the speed or quantity of activity. In the diagram above, the delta wave has the largest amplitude. The beta wave has the highest frequency (14-30 Hz). EEG is often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity (i.e. no particular rhythm) may indicate neurological abnormalities such as epilepsy, tumours or disorders of sleep. Strengths Weaknesses EEG has been very valuable at helping Only general information is received diagnose conditions such as epilepsy, from an EEG (the activity of many depression and schizophrenia because thousands of neurons). the difference in brain activity can be detected on the screen. EEG is not useful in pinpointing the exact source of neural activity and does not It has contributed to our understanding of allow researchers to tell the difference the stages of between activity in locations that are very close to one another. It has extremely high temporal resolution (unlike fMRI) it can accurately detect in a single millisecond. potentials (ERPs) ERP’s use similar equipment to EEG (electrodes attached to the however, a stimulus is presented to a participant i.e. picture or sound, and the researcher looks for activity related to the stimulus and investigate how an EEG wave pattern changes in response to the stimulus. This change is an ERP. (Types of brainwaves triggered by particular events).
fMRI can only measure blood flow in the brain, it cannot tell us the exact activity of individual neurons and so it can be difficult to tell what kind of brain activity is being represented on the screen. Electroencephalogram (EEG) EEGs measure electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap. The scan recording represents the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity. The main 4 of EEG waves are alpha, beta, theta and delta. Scientists can also measure activity through amplitude and frequency. Amplitude is the intensity or size of activity, frequency is the speed or quantity of activity. In the diagram above, the delta wave has the largest amplitude. The beta wave has the highest frequency (14-30 Hz). EEG is often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity (i.e. no particular rhythm) may indicate neurological abnormalities such as epilepsy, tumours or disorders of sleep. Strengths Weaknesses EEG has been very valuable at helping diagnose conditions such as epilepsy, depression and schizophrenia because the difference in brain activity can be detected on the screen. It has contributed to our understanding of the stages of It has extremely high temporal resolution (unlike fMRI) it can accurately detect in a single millisecond. Only general information is received from an EEG (the activity of many thousands of neurons). EEG is not useful in pinpointing the exact source of neural activity and does not allow researchers to tell the difference between activity in locations that are very close to one another. potentials (ERPs) ERP’s use similar equipment to EEG (electrodes attached to the however, a stimulus is presented to a participant i.e. picture or sound, and the researcher looks for activity related to the stimulus and investigate how an EEG wave pattern changes in response to the stimulus. This change is an ERP. (Types of brainwaves triggered by particular events).
biopsychology_pack_2018.docx