100%(2)2 out of 2 people found this document helpful
This preview shows page 10 - 12 out of 37 pages.
consonant strings (only activates basic visual recognition)oFINDINGSLarge individual differences in patterns of activationOverall trends in Wernicke’s/Broca’s but other areas activated too Language is not simply localized-It is difficult to see how a single function could underlie a collection of effects, neural correlates of cog function overlap a lot and our models of the brain need to continue to beimprovedMagnoetencephalography (MEG)-fMRI has good spatial, but bad temporal compared to ERP-Magnoetencephalography (MEG)= non- invasive brain imaging technique that directlymeasures neural activity-Advantages:oHas high spatial of fMRI (not as high) AND high temporal of ERP (bc measures magnetic fields produced by brain)oProvides direct measure of neural changes (PET and fMRI are indirect bc linked to blood flow)oHead/skull abnormalities don’t effect the magnetic fields produced by head (unlike the electrical fields produced by ERP)-2 limitations:oCan only detect signal near cortical surface oNot cost effective / widely available Connectionist Models
-Connectionism= theory focussed on the way cog processes work at the physiological/neurological (as opposed to info processing) level. It holds that the brain consists of networks of simple units (neurons) communicating with one another oAlternative theory, that the brain consists of interconnected neuronso2 basic ideas of connectionism1 – info can be broken down into simple units (neurons)2 – there are connections between these units -Can understand these neural connections through neural imaging techniques such asoDiffusion tension imaging (DTI) = MRI based neuroimaging technique that makes it possible to visualize the white matter tracts in the brain -Neural network= neurons that are functionally related/connectedoNeural connections have different strengths, networks learn by modifying strengthof connections so that the proper output occurs in response to a particular input -One assumption…-Hebb rule= connection between two neurons takes place only if both neurons are firing at approx. the same time oWhen axon of A is near enough to excite B and repeatedly takes part in firing it, some growth process/metabolic change takes place in one/both cells such that A’s efficiency, as one of the cells firing B, is increased-Another assumption is that many connections can be active at same timeoParallel processing= many neural connections can be active at same time – in contrast to serial processing(only 1 neural activity may take place at a time) -Tf connectionist models are called ‘parallel distributed processing models’-Big dif between connectionism and older info processing is that knowledge is embodied in the connections that make up the network, rather than in a series of info processing stages; connectionist models are good at simulating many cog processesCombining Methods-Cog neuroscience melds all of these methods/theories-Hypotheses about brain mechanisms are made from careful control of behaviour using