Compare And Contrast Fmri And Electroencephaloggraphy

Compare and contrast the neuroimaging techniques of ERP and fMRI in terms of their relative advantages and disadvantages. Then, choosing just one technique, discuss how this has been used to address one aspect of cognitive psychology that interests you.
Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are two techniques commonly used to noninvasively examine functions within the human brain. When independent of one another these methods fail to provide sufficient information to understand the spatio-temporal aspects of information processing in the human brain. Electroencephalography (EEG) refers to the measurement of electrical activity within the brain, specific neural responses can be calculated by the changes
fMRI, therefore, is not strictly a quantitative measure of mental activity however, it is more objective than using typical qualitative measures. The BOLD signal associated with fMRI can only measure brain activity indirectly. ERP, on the other hand, provides a direct measure between stimulus and response which is recorded by the electrodes at the scalp (Liotti, Woldorff, Perez, & Mayberg 2000). The BOLD signal in fMRI is at risk of being influenced a number of factors that may cause non-neural changes in the body such as- drugs, age, attention and brain pathology. It is therefore difficult to interpret positive and negative BOLD responses owing to the fact that fMRI is only an indirect measure of neural activity (Morita, Fukuda, Kikuchi, Ikeda, Yumoto, & Sato,
Itier and Taylor (2004) conducted a study involving 450 gray-scale pictures including upright and inverted faces. ERP recordings showed that attention to a facial stimulus was about 25 msec faster than attention to a non-face object. Participants were able to recognise faces faster than other images irrespective of their relevance and orientation in the visual display. These results may provide evidence for specific face perception and recognition abilities in the temporal domain (Itier & Taylor 2004). Results were very similar with those presented in Caldera, Thut, Servoir, Michel, Bovit and Renault (2003) race facial study. Caldera et al 2003 indicated that human’s process faces quicker than objects even if they are not of the same race. ERP results suggested that humans are slightly slower to recognize and respond to a face if it is not the same race but are still significantly faster at acknowledging them than an alternative stimulus. The N2pc component placed further emphasis on the significance of faces compared to other stimuli. Eimer and Kiss (2007) demonstrated how, even when faces were named ‘irrelevant stimuli’, individuals still produced a significant negative response (N2pc). ERP recordings indicated how individuals shifted their attention from relevant stimuli to fearful faces in the visual display. This supports the notion that our