14 THE STUDENT'S GUIDE TO COGNITIVE NEUROSCIENCE than the micro level of individual synapses).The proiect is based on mrl @ techniques that measure structural connectivity (essentially white matter fibers)and functional connectivity (essentially correlated patterns of brain ONLINE RESOURCES be possible to identify differences in the connectome that are linked to disease and also of particular relevance here to understand how these networks cognitive function.This can be done by.for instance. Connectome Project nces in the cor nectome to individual differences in specific and watch TED asncomenm it also equires the in ists who the co ea2chnanag understand cognition.A complementary roach is to map at the linked ale of individus s is a dau tas the the companion website t conne at www. By of a h (3x10).Aside ode” there is mapping n the code and the protei mple KEY TERM rks wer re from the star Graph theory in the dscape looks agram A mathematical tect nique for archi ectur support biologically wiring diagram)froma the stru and runct upporte y ad ch as graph ory(B Sporn set of correlations 09 This e entially create wiring d gram,rather e a sub way map in wh ome brain regions act as central hubs within the (wher way lines cros in that analogy)and regions are suburbs,in that analogy).Secondly,there has been a shif away from conceptualizing the hubs in the network as highly specialized units.Instead,brain regions might perform a range of different functions depending on which other parts of the brain they are communicating with A good example is Broca's region itself which.whilst everyone agrees it is important for language.seems to also be involved in other cognitive processes such as detecting musical violations(Koelsch et al.,2006). Does this mean that the era of functional specialization.stretching from phrenology through to Broca and Penfield,is now over?This is certainly not the case.It has even been argued on first principles that if the brain is a network then the different hubs in the network must have different functional specializations(Sporns Betzel,2016),except in the hypothetical scenario that all regions in the network connect equally strongly to each other(in which case each hub is identical).However,the function assigned to a region may be harder to map onto simple cognitive concepts in this new framework.For instance,the function of a brain region may be something like "integrating vision and speech"rather than"a store of words." Thus.the central challenge for cognitive neuroscience for the future is to develop new ways of describing the relationship between brain structure (notably connectomics)and function (i.e.,cognition and behavior).Barrett and Satpute(2013)offer a useful summary of three different approaches as shown in Figure 1.9.In the first scenario (a).there is a very simple one-to-one mapping between different brain regions and different cognitive functions
14 THE STUDENT’S GUIDE TO COGNITIVE NEUROSCIENCE than the micro level of individual synapses). The project is based on MRI techniques that measure structural connectivity (essentially white matter fibers) and functional connectivity (essentially correlated patterns of brain activity between regions). By scanning and testing thousands of people it will be possible to identify differences in the connectome that are linked to disease and also, of particular relevance here, to understand how these networks support cognitive function. This can be done by, for instance, linking individual differences in the connectome to individual differences in specific cognitive abilities (Barch et al., 2013). Thus, it is not just an enterprise for biologists and neuroimagers—it also requires the input of psychologists who understand cognition. A complementary approach is to map the connectome at the micro scale of individual synapses. This is a daunting prospect as there are 1010 neurons linked by 1014 synaptic connections (Azevedo et al., 2009). By comparison, the size of a human genome is far smaller (3×109 ). Aside from the sheer scale of this challenge, there is no obvious way of interpreting the connectome “code” (unlike the genome where there is a simple mapping between the code and the proteins they create). Of course, networks are nothing new. Networks were there from the start in the form of black-box-and-arrow diagrams. However, the contemporary and emerging landscape looks very different from this. Firstly, the network architecture that supports cognition is derived from biologically based observations of the structural and functional connectome. This is supported by advanced mathematical tools such as graph theory (Bullmore & Sporns, 2009). This essentially creates a wiring diagram, rather like a subway map, in which some brain regions act as central hubs within the network (where several subway lines cross, in that analogy) and other regions are less connected (the suburbs, in that analogy). Secondly, there has been a shift away from conceptualizing the hubs in the network as highly specialized units. Instead, brain regions might perform a range of different functions depending on which other parts of the brain they are communicating with. A good example is Broca’s region itself which, whilst everyone agrees it is important for language, seems to also be involved in other cognitive processes such as detecting musical violations (Koelsch et al., 2006). Does this mean that the era of functional specialization, stretching from phrenology through to Broca and Penfield, is now over? This is certainly not the case. It has even been argued on first principles that if the brain is a network then the different hubs in the network must have different functional specializations (Sporns & Betzel, 2016), except in the hypothetical scenario that all regions in the network connect equally strongly to each other (in which case each hub is identical). However, the function assigned to a region may be harder to map onto simple cognitive concepts in this new framework. For instance, the function of a brain region may be something like “integrating vision and speech” rather than “a store of words.” Thus, the central challenge for cognitive neuroscience for the future is to develop new ways of describing the relationship between brain structure (notably connectomics) and function (i.e., cognition and behavior). Barrett and Satpute (2013) offer a useful summary of three different approaches as shown in Figure 1.9. In the first scenario (a), there is a very simple one-to-one mapping between different brain regions and different cognitive functions. ONLINE RESOURCES Delve deeper into the Human Connectome Project (humanconnectome. org) and watch TEDx talks on connectomics by Jeff Lichtman and David van Essen. Visit the companion website at www.routledge. com/cw/ward. KEY TERM Graph theory A mathematical technique for computing the pattern of connectivity (or “wiring diagram”) from a set of correlations
INTRODUCING COGNITIVE NEUROSCIENCE 15 b】 tior E.g.Judging a an at DO E.g Judging a o an a Task Domain Soecificit g Exp Eg小9a EIGURE 1 9:Three different ways in which different brain str different functions (tasks and roc 8oh包theeeaOneoCentbem brain structure and function whereas in both(b)and(c)a network of regions may make to a give In (b) of specialized unit act,but in (c)the From Barrett and Satpute (2013)
Introducing cognitive neuroscience 15 FIGURE 1.9: Three different ways in which different brain structures might be mapped to different functions (tasks and processes). In (a) there is a one-to-one association between brain structure and function whereas in both (b) and (c) a network of regions may make different contributions to a given function. In (b) the network consists of specialized units that interact, but in (c) the network consists of interactions between nonspecialized units. From Barrett and Satpute (2013)
16 THE STUDENT'S GUIDE TO COGNITIVE NEUROSCIENCE Few researchers would endorse such a view.In the second scenario (b).there is still a high degree of specialization of brain regions but multiple regions need to interact to generate a cognitive function.In the third scenario (c) there is far less specialization of regions and cognitive functions are generated by the interaction of multiple networks(with each network having some SUMMARY AND KEY POINTS OF THE CHAPTER The mind-body problem refers to the question of how physical matter(the brain)can produce mental experiences.and this remains an enduring issue in cognitive neuroscience. To some extent,the different regions of the brain are specialized Functional neuroimaging has provided the driving force for much of the development of cognitive neuroscience,but there is a danger in merely using these methods to localize cognitive @ without understanding howth ONLINE RESOURCES measures can provide an alternative source of evidence to inform Visit the companion wehsite at www cognitive theory and the brain must provide constraining factors routledge.com/cw/ward on the nature and development of the information-processing for: models of cognitive scier Attempting tomap the huma an connectome,and link it to cognition,is the greatest challenge for the next generation of cognitive neuroscientists.Although old concepts will remain(e.g. the idea of functional specialization).they may be understood in with leading entirely new ways. neuroscientists Wilder Penfield and EXAMPLE ESSAY QUESTIONS Multinle-choice questions and .What is the"mind-body problem"and what frameworks have interactive flashcards been put forward to solve it? to test your Is cognitive neuroscience the new phrenology? nowledge Does cognitive psychology need the brain?Does neuroscience le need cognitive psychology? glossary
16 THE STUDENT’S GUIDE TO COGNITIVE NEUROSCIENCE Few researchers would endorse such a view. In the second scenario (b), there is still a high degree of specialization of brain regions but multiple regions need to interact to generate a cognitive function. In the third scenario (c) there is far less specialization of regions and cognitive functions are generated by the interaction of multiple networks (with each network having some specialization). Barrett and Satpute (2013) favor this third option, although others argue that the cognitive architecture of the brain is more like the second option (Vytal & Hamann, 2010). SUMMARY AND KEY POINTS OF THE CHAPTER • The mind–body problem refers to the question of how physical matter (the brain) can produce mental experiences, and this remains an enduring issue in cognitive neuroscience. • To some extent, the different regions of the brain are specialized for different functions. • Functional neuroimaging has provided the driving force for much of the development of cognitive neuroscience, but there is a danger in merely using these methods to localize cognitive functions without understanding how they work. • Cognitive psychology has developed as a discipline without making explicit references to the brain. However, biological measures can provide an alternative source of evidence to inform cognitive theory and the brain must provide constraining factors on the nature and development of the information-processing models of cognitive science. • Attempting to map the human connectome, and link it to cognition, is the greatest challenge for the next generation of cognitive neuroscientists. Although old concepts will remain (e.g., the idea of functional specialization), they may be understood in entirely new ways. ONLINE RESOURCES Visit the companion website at www. routledge.com/cw/ward for: • References to key papers and readings • Video interviews on key topics with leading neuroscientists Wilder Penfield and Michael Gazzaniga, and philosopher Ned Block • Multiple-choice questions and interactive flashcards to test your knowledge • Downloadable glossary EXAMPLE ESSAY QUESTIONS • What is the “mind–body problem” and what frameworks have been put forward to solve it? • Is cognitive neuroscience the new phrenology? • Does cognitive psychology need the brain? Does neuroscience need cognitive psychology?
INTRODUCING COGNITIVE NEUROSCIENCE 17 RECOMMENDED FURTHER READING Henson,R.(2005).What can functional neuroimaging tell the experimental psychologist?Quarterly Journal of Experimental criticisms.This debate can also be followed in a series of articles in Cortex(2006,42,387-427). .Shallice,T.,Cooper,R.P.(2011).The organisation of mind. ceptual present chapter in more detail. Uttal,W.R.(2001).The new phrenology:The limits of localizing cognitive processes in the brain.Cambridge,MA:MIT Press.An interesting overview of the methods and limitations of cognitive neuroscience Wickens.A.P.(2015).A history of the brain:How we have come to understand the most complex object in the universe.New York:Psychology Press.A good place to start for the history of neuroscience
Introducing cognitive neuroscience 17 RECOMMENDED FURTHER READING • Henson, R. (2005). What can functional neuroimaging tell the experimental psychologist? Quarterly Journal of Experimental Psychology, 58A, 193–233. An excellent summary of the role of functional imaging in psychology and a rebuttal of common criticisms. This debate can also be followed in a series of articles in Cortex (2006, 42, 387–427). • Shallice, T., & Cooper, R. P. (2011). The organisation of mind. Oxford, UK: Oxford University Press. The chapters on “conceptual foundations” deal with many of the issues touched on in the present chapter in more detail. • Uttal, W. R. (2001). The new phrenology: The limits of localizing cognitive processes in the brain. Cambridge, MA: MIT Press. An interesting overview of the methods and limitations of cognitive neuroscience. • Wickens, A. P. (2015). A history of the brain: How we have come to understand the most complex object in the universe. New York: Psychology Press. A good place to start for the history of neuroscience
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