Editing Semantic memory (section)

== Neural correlates and biological workings ==
The hippocampal areas associate semantic memory with declarative memory. The left inferior [[prefrontal cortex]] and the left posterior [[Temporal lobe|temporal]] areas are other areas involved in semantic memory use. [[Temporal lobe]] damage affecting the lateral and medial cortexes have been related to semantic impairments. Damage to different areas of the brain affect semantic memory differently.<ref name="Autobiographical, Episodic 2007">{{cite journal | last1 = Burianova | first1 = H. | last2 = Grady | first2 = C. L. | year = 2007 | title = Common and Unique Neural Activations in Autobiographical, Episodic, and Semantic Retrieval | url = http://espace.library.uq.edu.au/view/UQ:320651/UQ320651_OA.pdf| journal = Journal of Cognitive Neuroscience | volume = 19 | issue = 9| pages = 1520–34 | doi=10.1162/jocn.2007.19.9.1520| pmid = 17714013 | s2cid = 6110963 }}</ref>

Neuroimaging evidence suggests that left hippocampal areas show an increase in activity during semantic memory tasks. During semantic retrieval, two regions in the right [[middle frontal gyrus]] and the area of the right [[inferior temporal gyrus]] similarly show an increase in activity.<ref name="Autobiographical, Episodic 2007"/> Damage to areas involved in semantic memory result in various deficits, depending on the area and type of damage. For instance, Lambon Ralph, Lowe, & Rogers (2007) found that category-specific impairments can occur where patients have different knowledge deficits for one semantic category over another, depending on location and type of damage.<ref name=":5">{{cite journal | last1 = Lambon Ralph | first1 = M. | last2 = Lowe | first2 = C. | last3 = Rogers | first3 = T.T. | year = 2007 | title = Neural Basis of Category-specific Semantic Deficits for Living Things: Evidence from semantic dementia, HSVE and a Neural Network Model | journal = Brain | volume = 130 | issue = 4| pages = 1127–37 | doi=10.1093/brain/awm025 | pmid=17438021| doi-access = free | url = https://research.manchester.ac.uk/files/22806563/POST-PEER-REVIEW-PUBLISHERS.PDF }}</ref> Category-specific impairments might indicate that knowledge may rely differentially upon sensory and motor properties encoded in separate areas (Farah and McClelland, 1991).{{Full citation needed|date=July 2023}}

Category-specific impairments can involve cortical regions where living and nonliving things are represented and where feature and conceptual relationships are represented. Depending on the damage to the semantic system, one type might be favored over the other. In many cases, there is a point where one domain is better than the other (such as the representation of living and nonliving things over feature and conceptual relationships or vice versa).<ref>{{cite journal | last1 = Garrard | display-authors = etal   | year = 2001 | title = Longitudinal Profiles of Semantic Impairment for Living and Nonliving Concepts in Dementia of Alzheimer's Type | journal = Journal of Cognitive Neuroscience | volume = 13 | issue = 7| pages = 892–909 | doi=10.1162/089892901753165818| pmid = 11595093   | s2cid = 36930117 | url = https://pure.manchester.ac.uk/ws/files/29049693/POST-PEER-REVIEW-PUBLISHERS.PDF }}</ref>

Different diseases and disorders can affect the biological workings of semantic memory. A variety of studies have been done in an attempt to determine the effects on varying aspects of semantic memory. For example, Lambon, Lowe, & Rogers studied the different effects [[semantic dementia]] and herpes simplex virus encephalitis have on semantic memory. They found that semantic dementia has a more generalized semantic impairment. Additionally, deficits in semantic memory as a result of herpes simplex virus encephalitis tend to have more category-specific impairments.<ref name=":5" /> Other disorders that affect semantic memory, such as [[Alzheimer's disease]], has been observed clinically as errors in naming, recognizing, or describing objects. Whereas researchers have attributed such impairment to degradation of semantic knowledge.<ref>{{cite journal | last1 = Lambon | first1 = R. | last2 = Matthew | first2 = A. | year = 2007 | title = Neural Basis of Category-specific Semantic Deficits for Living Things: Evidence from semantic dementia, HSVE and a Neural Network Model | journal = Brain | volume = 130 | issue = 4| pages = 1127–37 | doi=10.1093/brain/awm025 | pmid=17438021| doi-access = free | url = https://pure.manchester.ac.uk/ws/files/22806563/POST-PEER-REVIEW-PUBLISHERS.PDF }}</ref>

Various neural imaging and research points to semantic memory and [[episodic memory]] resulting from distinct areas in the brain. Other research suggests that both semantic memory and episodic memory are part of a singular declarative memory system, yet represent different sectors and parts within the greater whole. Different areas within the brain are activated depending on whether semantic or episodic memory is accessed.<ref>{{cite journal | last1 = Rajah | first1 = M.N. | last2 = McIntosh | first2 = A.R. | year = 2005 | title = Overlap in the Functional Neural Systems Involved in Semantic and Episodic Memory Retrieval | journal = Journal of Cognitive Neuroscience | volume = 17 | issue = 3| pages = 470–482 | doi=10.1162/0898929053279478| pmid = 15814006 | s2cid = 22334103 | url = http://direct.mit.edu/jocn/article-pdf/17/3/470/1935153/0898929053279478.pdf }}</ref>