Editing Broca's area (section)

== Structure ==
[[File:Brodmann Cytoarchitectonics 44.png|left|120 px|[[Brodmann area 44]]]]
[[File:Brodmann Cytoarchitectonics 45.png|left|120px|[[Brodmann area 45]]]]
Broca's area is often identified by visual inspection of the [[topography]] of the brain either by macrostructural landmarks such as [[Sulcus (neuroanatomy)|sulci]] or by the specification of coordinates in a particular reference space. The currently used [[Talairach coordinates|Talairach and Tournoux atlas]] projects [[Korbinian Brodmann|Brodmann's]] [[Brodmann area|cytoarchitectonic map]] onto a template brain. Because Brodmann's [[Brain mapping|parcelation]] was based on subjective visual inspection of cytoarchitectonic borders and also Brodmann analyzed only one hemisphere of one brain, the result is imprecise. Further, because of considerable variability across brains in terms of shape, size, and position relative to sulcal and gyral structure, a resulting localization precision is limited.<ref name="pmid18930695">{{cite journal | vauthors = Grodzinsky Y, Santi A | title = The battle for Broca's region | journal = Trends in Cognitive Sciences | volume = 12 | issue = 12 | pages = 474–80 | date = December 2008 | pmid = 18930695 | doi = 10.1016/j.tics.2008.09.001 | s2cid = 13023258 }}</ref>

Nevertheless, Broca's area in the left hemisphere and its homologue in the right [[Cerebral hemisphere|hemisphere]] are designations usually used to refer to the [[triangular part of inferior frontal gyrus]] (PTr) and the [[opercular part of inferior frontal gyrus]] (POp). The PTr and POp are defined by structural landmarks that only probabilistically divide the [[inferior frontal gyrus]] into anterior and posterior cytoarchitectonic areas of 45 and 44, respectively, by [[Korbinian Brodmann|Brodmann]]'s classification scheme.<ref name="pmid17533001">{{cite journal | vauthors = Skipper JI, Goldin-Meadow S, Nusbaum HC, Small SL | title = Speech-associated gestures, Broca's area, and the human mirror system | journal = Brain and Language | volume = 101 | issue = 3 | pages = 260–77 | date = June 2007 | pmid = 17533001 | pmc = 2703472 | doi = 10.1016/j.bandl.2007.02.008 }}</ref>

Area 45 receives more [[Afferent nerve fiber|afferent connections]] from the [[prefrontal cortex]], the [[superior temporal gyrus]], and the [[superior temporal sulcus]], compared to area 44, which tends to receive more afferent connections from motor, [[somatosensory]], and inferior parietal regions.<ref name="pmid17533001" />

The differences between area 45 and 44 in cytoarchitecture and in connectivity suggest that these areas might perform different functions. Indeed, recent [[neuroimaging]] studies have shown that the PTr and Pop, corresponding to areas 45 and 44, respectively, play different functional roles in the human with respect to language comprehension and action recognition/understanding.<ref name="pmid17533001" />

The Broca's area is about 20% larger in women than in men.<ref>{{cite journal | vauthors = Schlaepfer TE, Harris GJ, Tien AY, Peng L, Lee S, Pearlson GD | year = 1995 | title = Structural differences in the cerebral cortex of healthy female and male subjects: a magnetic resonance imaging study | journal = Psychiatry Res | volume = 61 | issue = 3| pages = 129–35 | doi = 10.1016/0925-4927(95)02634-a | pmid = 8545497 | s2cid = 25425465 | doi-access = free }}</ref>