Editing Neurolinguistics (section)

==Technology used==
{{Multiple image|direction=vertical|align=right|image1=PET-image.jpg|image2=Functional magnetic resonance imaging.jpg|width=150|caption2=Images of the brain recorded with [[Positron emission tomography|PET]] (top) and [[fMRI]] (bottom). In the PET image, the red areas are the most active. In the fMRI image, the yellowest areas are the areas that show the greatest difference in activation between two tasks (watching a moving stimulus, versus watching a black screen).}}
Since one of the focuses of this field is the testing of linguistic and psycholinguistic models, the technology used for experiments is highly relevant to the study of neurolinguistics. Modern brain imaging techniques have contributed greatly to a growing understanding of the anatomical organization of linguistic functions.<ref name="phillipssakai"/><ref name="LSA">{{cite web | publisher=[[Linguistic Society of America]] | last=Menn | first=Lise | access-date=18 December 2008 | title=Neurolinguistics | url=http://www.lsadc.org/info/ling-fields-neuro.cfm | archive-url=https://web.archive.org/web/20081211081710/http://www.lsadc.org/info/ling-fields-neuro.cfm | archive-date=11 December 2008 | url-status=dead }}</ref>  Brain imaging methods used in neurolinguistics may be classified into [[hemodynamic]] methods, [[Electrophysiology|electrophysiological]] methods, and methods that stimulate the cortex directly.

===Hemodynamic===
{{Main|Neuroimaging}}
Hemodynamic techniques take advantage of the fact that when an area of the brain works at a task, blood is sent to supply that area with oxygen (in what is known as the Blood Oxygen Level-Dependent, or BOLD, response).<ref name="ward">{{cite book | last=Ward | first=Jamie | year=2006 | chapter=The imaged brain | title=The Student's Guide to Cognitive Neuroscience | isbn=978-1-84169-534-1 | publisher=Psychology Press}}</ref>  Such techniques include [[Positron emission tomography|PET]] and [[fMRI]].  These techniques provide high ''spatial resolution'', allowing researchers to pinpoint the location of activity within the brain;<ref name="phillipssakai"/> ''temporal resolution'' (or information about the timing of brain activity), on the other hand, is poor, since the BOLD response happens much more slowly than language processing.<ref name="weisler293">Weisler (1999), p. 293.</ref><ref name="kutas">{{cite journal | year=2002 | volume=4 | issue=12 | journal=[[Trends (journals)|Trends in Cognitive Sciences]] | last1=Kutas | first1=Marta |author2=Kara D. Federmeier | author-link2=Kara Federmeier|title=Electrophysiology reveals memory use in language comprehension}}</ref>  In addition to demonstrating which parts of the brain may subserve specific language tasks or computations,<ref name=embicketal/><ref name="friederici2002">{{cite journal | last=Friederici | first=Angela D. | year=2002 | journal=[[Trends (journals)|Trends in Cognitive Sciences]] | title=Towards a neural basis of auditory sentence processing | volume=6 | issue=2 | pages=78&ndash;84 | doi=10.1016/S1364-6613(00)01839-8| pmid=15866191 | doi-access=free | hdl=11858/00-001M-0000-0010-E573-8 | hdl-access=free }}</ref> hemodynamic methods have also been used to demonstrate how the structure of the brain's language architecture and the distribution of language-related activation may change over time, as a function of linguistic exposure.<ref name=wangetal>{{cite journal | year=2003 |author1=Wang Yue |author2=Joan A. Sereno; Allard Jongman; and Joy Hirsch | title=fMRI evidence for cortical modification during learning of Mandarin lexical tone | pmid=14614812 | journal=Journal of Cognitive Neuroscience | volume=15 | issue=7 | pages=1019&ndash;1027 | doi=10.1162/089892903770007407|hdl=1808/12458 |s2cid=4812588 | url=https://kuscholarworks.ku.edu/bitstream/1808/12458/1/JongmanJCN15.pdf | hdl-access=free }}</ref><ref name=sereno/>

In addition to PET and fMRI, which show which areas of the brain are activated by certain tasks, researchers also use [[diffusion tensor imaging]] (DTI), which shows the neural pathways that connect different brain areas,<ref name=Filler1992>Filler AG, Tsuruda JS, Richards TL, Howe FA: Images, apparatus, algorithms and methods. GB 9216383, UK Patent Office, 1992.</ref> thus providing insight into how different areas interact. [[Functional near-infrared spectroscopy]] (fNIRS) is another hemodynamic method used in language tasks.<ref name="dieleretal2011">{{cite journal | first1=Ana Inés | last1=Ansaldo | first2=Karima | last2=Kahlaoui | first3=Yves | last3=Joanette | title=Functional near-infrared spectroscopy: Looking at the brain and language mystery from a different angle | journal=Brain and Language | year=2011 | volume=121 | issue=2, number 2 |pages=77–8 |doi=10.1016/j.bandl.2012.03.001| pmid=22445199 | s2cid=205792249 }}</ref>

===Electrophysiological===
[[File:Spike-waves.png|left|thumb|Brain waves recorded using [[Electroencephalography|EEG]]]]
Electrophysiological techniques take advantage of the fact that when a group of neurons in the brain fire together, they create an [[Dipole|electric dipole]] or current.  The technique of [[Electroencephalography|EEG]] measures this electric current using sensors on the scalp, while [[Magnetoencephalography|MEG]] measures the magnetic fields that are generated by these currents.<ref name="tracking"/> In addition to these non-invasive methods, [[electrocorticography]] has also been used to study language processing. These techniques are able to measure brain activity from one millisecond to the next, providing excellent ''temporal resolution'', which is important in studying processes that take place as quickly as language comprehension and production.<ref name="tracking">{{cite journal | journal=[[Trends (journals)|Trends in Cognitive Sciences]] | year=2003 | volume=7 | issue=5 | title=Tracking the time course of word recognition with MEG | last1=Pylkkänen | first1=Liina |author2=Alec Marantz | pages=187&ndash;189 | doi=10.1016/S1364-6613(03)00092-5| pmid=12757816 | s2cid=18214558 | author2-link=Alec Marantz | doi-access=free }}</ref>  On the other hand, the location of brain activity can be difficult to identify in EEG;<ref name="kutas"/><ref name="van petten?">{{cite journal | last1=Van Petten | first1=Cyma | last2=Luka | first2=Barbara | title=Neural localization of semantic context effects in electromagnetic and hemodynamic studies | year=2006 | journal=Brain and Language | volume=97 | issue=3 | pages=279–93 | doi = 10.1016/j.bandl.2005.11.003 | pmid=16343606 | s2cid=46181 }}</ref> consequently, this technique is used primarily to ''how'' language processes are carried out, rather than ''where''.  Research using EEG and MEG generally focuses on [[event-related potential]]s (ERPs),<ref name="kutas"/> which are distinct brain responses (generally realized as negative or positive peaks on a graph of neural activity) elicited in response to a particular stimulus.  Studies using ERP may focus on each ERP's ''latency'' (how long after the stimulus the ERP begins or peaks), ''amplitude'' (how high or low the peak is), or ''topography'' (where on the scalp the ERP response is picked up by sensors).<ref>{{cite book | chapter-url=http://l3d.cs.colorado.edu/~ctg/classes/lib/cogsci/Rugg-ColesChp1.pdf | chapter=Event-related brain potentials: an introduction | year=1996 | title=Electrophysiology of Mind | pages=[https://archive.org/details/electrophysiolog0000unse_z3l2/page/1 1&ndash;27] | publisher=Oxford Scholarship Online Monographs | author2=Michael D. Rugg | last1=Coles | first1=Michael G.H. | isbn=978-0-19-852135-8 | url=https://archive.org/details/electrophysiolog0000unse_z3l2/page/1 }}</ref> Some important and common ERP components include the [[N400 (neuroscience)|N400]] (a negativity occurring at a latency of about 400 milliseconds),<ref name="kutas"/> the [[mismatch negativity]],<ref name="pulvermulleretal2008"/> the [[early left anterior negativity]] (a negativity occurring at an early latency and a front-left topography),<ref name="frisch194"/> the [[P600 (neuroscience)|P600]],<ref name=neurocognition280/><ref>{{cite journal | last1=Kaan | first1=Edith |author2=Swaab, Tamara | year=2003 | journal=Journal of Cognitive Neuroscience | volume=15 | pmid=12590846 | issue=1 | pages=98&ndash;110 | title=Repair, revision, and complexity in syntactic analysis: an electrophysiological differentiation| doi=10.1162/089892903321107855| s2cid=14934107 }}</ref> and the [[lateralized readiness potential]].<ref name=vanTurrenout>{{cite journal | last1=van Turrenout | first1=Miranda | last2=Hagoort | first2=Peter | last3=Brown | first3=Colin M | year=1998 | journal=[[Science (journal)|Science]] | volume=280 | title=Brain activity during speaking: from syntax to phonology in 40 milliseconds | pmid=9554845 | issue=5363 | pages=572–4 | doi=10.1126/science.280.5363.572| bibcode=1998Sci...280..572V | hdl=21.11116/0000-0002-C13A-3 | hdl-access=free }}</ref>