Amnesia: Difference between revisions
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'''Amnesia''' is a global impairment in the ability to acquire new memories regardless of sensory modality, and a loss of some memories, especially recent ones, from the period before amnesia began.<ref name=" | '''Amnesia''' is a global impairment in the ability to acquire new memories regardless of sensory modality, and a loss of some memories, especially recent ones, from the period before amnesia began.<ref name="SquireZola1997">{{cite journal|last1=Squire|first1=L. R.|last2=Zola|first2=S. M.|title=Amnesia, memory and brain systems|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=352|issue=1362|year=1997|pages=1663–1673|issn=0962-8436|doi=10.1098/rstb.1997.0148}}</ref> During states of amnesia a person will usually retain functional perceptual abilities and short-term memory which can still be used to recall events that recently occurred; this effect is distinct from the memory impairment produced by [[sedation]].<ref>Veselis, R. A., Reinsel, R. A., & Feshchenko, V. A. (2001). Drug-induced Amnesia Is a Separate Phenomenon from Sedation: Electrophysiologic Evidence. Anesthesiology: The Journal of the American Society of Anesthesiologists, 95(4), 896-907. https://www.ncbi.nlm.nih.gov/pubmed/11605930</ref> As such, a person experiencing amnesia may not obviously appear to be doing so, as they can often carry on normal conversations and perform complex tasks. | ||
This state of mind is commonly referred to as a "blackout", an experience that can be divided into 2 formal categories: "fragmentary" blackouts and "en bloc" blackouts.<ref>Hartzler | This state of mind is commonly referred to as a "blackout", an experience that can be divided into 2 formal categories: "fragmentary" blackouts and "en bloc" blackouts.<ref name="HartzlerFromme2003">{{cite journal|last1=Hartzler|first1=Bryan|last2=Fromme|first2=Kim|title=Fragmentary and en bloc blackouts: similarity and distinction among episodes of alcohol-induced memory loss.|journal=Journal of Studies on Alcohol|volume=64|issue=4|year=2003|pages=547–550|issn=0096-882X|doi=10.15288/jsa.2003.64.547}}</ref> Fragmentary blackouts, sometimes known as "brownouts", are characterized by having the ability to recall specific events from an intoxicated period but remaining unaware that certain memories are missing until reminded of the existence of those gaps in memory. Studies suggest that fragmentary blackouts are far more common than "en bloc" blackouts.<ref>White, A. M., Signer, M. L., Kraus, C. L., & Swartzwelder, H. S. (2004). Experiential aspects of alcohol‐induced blackouts among college students. The American journal of drug and alcohol abuse, 30(1), 205-224. https://www.ncbi.nlm.nih.gov/pubmed/15083562</ref> In comparison, En bloc blackouts are characterized by a complete inability to later recall any memories from an intoxicated period, even when prompted. It is usually difficult to determine the point at which this type of blackout has ended as sleep typically occurs before this happens.<ref name="GoodwinCrane1969">{{cite journal|last1=Goodwin|first1=Donald W.|last2=Crane|first2=J. Bruce|last3=Guze|first3=Samuel B.|title=Alcoholic "Blackouts": A Review and Clinical Study of 100 Alcoholics|journal=American Journal of Psychiatry|volume=126|issue=2|year=1969|pages=191–198|issn=0002-953X|doi=10.1176/ajp.126.2.191}}</ref> | ||
Amnesia is often accompanied by other coinciding effects such as [[disinhibition]], [[sedation]], and [[memory suppression]]. It is most commonly induced under the influence of [[dosage#heavy|heavy]] [[dosage|dosages]] of [[GABAergic]] [[depressant|depressants]], such as [[alcohol]],<ref>Lee | Amnesia is often accompanied by other coinciding effects such as [[disinhibition]], [[sedation]], and [[memory suppression]]. It is most commonly induced under the influence of [[dosage#heavy|heavy]] [[dosage|dosages]] of [[GABAergic]] [[depressant|depressants]], such as [[alcohol]],<ref name="LeeRoh2009">{{cite journal|last1=Lee|first1=Hamin|last2=Roh|first2=Sungwon|last3=Kim|first3=Dai Jin|title=Alcohol-Induced Blackout|journal=International Journal of Environmental Research and Public Health|volume=6|issue=11|year=2009|pages=2783–2792|issn=1660-4601|doi=10.3390/ijerph6112783}}</ref> [[benzodiazepines]],<ref>Mejo, S. L. (1992). Anterograde amnesia linked to benzodiazepines. The Nurse Practitioner, 17(10), 44-49. https://www.ncbi.nlm.nih.gov/pubmed/1357612</ref> [[GHB]],<ref name="BarkerHarris2007">{{cite journal|last1=Barker|first1=Judith C.|last2=Harris|first2=Shana L.|last3=Dyer|first3=Jo E.|title=Experiences of Gamma Hydroxybutyrate (GHB) Ingestion: A Focus Group Study|journal=Journal of Psychoactive Drugs|volume=39|issue=2|year=2007|pages=115–129|issn=0279-1072|doi=10.1080/02791072.2007.10399870}}</ref> and [[zolpidem]]<ref>Canaday, B. R. (1996). Amnesia possibly associated with zolpidem administration. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 16(4), 687-689. https://www.ncbi.nlm.nih.gov/pubmed/8840378</ref>. However, it can also occur to a much lesser extent under the influence of extremely heavy dosages of [[hallucinogen|hallucinogenic]] compounds such as [[psychedelic|psychedelics]], [[dissociative|dissociatives]], [[Salvia divinorum]], and [[deliriant|deliriants]]. | ||
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===Psychoactive substances=== | ===Psychoactive substances=== |