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| [1.] Jm/Fragment 038 01 - Diskussion Zuletzt bearbeitet: 2014-01-11 09:40:48 Hindemith | Beckner et al 2006, Fragment, Gesichtet, Jm, SMWFragment, Schutzlevel sysop, Verschleierung |
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| Untersuchte Arbeit: Seite: 38, Zeilen: 1-25 |
Quelle: Beckner et al 2006 Seite(n): 518-519, Zeilen: 518:right col. 22ff - 519:left col. 1ff |
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| [In many of the human studies demonstrating an] impairing effect of elevated cortisol on memory, the stressor or glucocorticoid is applied before stimulus presentation and learning, and recall is tested within 1–2 hours. In such a paradigm, cortisol levels are elevated during all memory phases: the learning period (initial encoding of the information), consolidation (the continuous transfer of information into longer term storage), and retrieval (recall of information from memory stores). Disruption of any one of these memory processes could account for detrimental effects of stress on memory and might also obscure any facilitated process. Roozendaal (2002) has theorized that under stressful conditions, consolidation of novel information related to the situation is enhanced such that one is more likely to later remember information associated with the stressful experience. However, in order to facilitate this new learning during arousing situations, competing processes of retrieving old information (which could result in retroactive interference) may be inhibited. Thus, it may be impaired retrieval that accounts for many of the human findings cited above, rather than stress effects on learning or consolidation.
Indeed, recent studies that have managed to isolate consolidation as a target process point to a facilitative effect of stress. These investigations typically administer the stress induction protocol or corticosteroids prior to or immediately following training (i.e., during encoding and consolidation), followed by retention testing at least 24 hr later. Retrieval is therefore tested after corticosterone levels have returned to baseline, thereby isolating the effect of glucocorticoids on consolidation of new memories. Animal studies using this paradigm have generally found a facilitative effect of moderate levels of glucocorticoids on consolidation (Conrad, Lupien & McEwen, 1999; Oitzl & de Kloet, 1992; Roozendaal & McGaugh, 1996; Sandi, Loscertales & Guaza, 1997). Several recent human studies have also found a facilitative effect of stress or administered cortisol on encoding and consolidation of visual information with affective content when recall is tested at least 24 hr after learning (Buchanan & Lovallo, 2001; Cahill, Gorski & Le, 2003); an additional study found this for [both emotionally arousing and neutral information (Abercrombie et al., 2003).] Abercrombie, H.C., Kalin, N.H., Thurow, M.E., Rosenkranz, M.A., & Davidson, R.J. (2003). Cortisol variation in humans affects memory for emotionally laden and neutral information. Behavioral Neuroscience, 117, 505-516. Buchanan, T.W. & Lovallo, W.R. (2001). Enhanced memory for emotional material following stress-level cortisol treatment in humans. Psychoneuroendocrinology, 26, 307–317. Cahill L, Gorski L, & Le K (2003). Enhanced human memory consolidation with post-learning stress: interaction with the degree of arousal at encoding. Learning and Memory, 10, 270–274. Conrad, C.D., Lupien, S.J., & McEwen, B.S. (1999). Support for a bimodal role for Type II adrenal steroid receptors in spatial memory. Neurobiology of Learning and Memory, 72, 39-46. Oitzl, M.S. & de Kloet, E.R. (1992). Selective corticosteroid antagonists modulate specific aspects of spatial orientation learning. Behavioural Neuroscience, 106, 62-71. Roozendaal, B. (2002). Stress and memory: opposing effects of glucocorticoids on memory consolidation and memory retrieval. Neurobiology of Learning and Memory, 78, 578-595. Roozendaal, B. & McGaugh, J.L. (1996). Amygdaloid nuclei lesions differentially affect glucocorticoid-induced memory enhancement in an inhibitory avoidance task. Neurobiology of Learning and Memory, 65, 1– 8. Sandi, C., Loscertales, M., & Guaza, C. (1997). Experience-dependent facilitating effect of corticosterone on spatial memory formation in the water maze. European Journal of Neuroscience, 9, 637–642. |
[Page 518]
In many of the human studies demonstrating an impairing effect of elevated cortisol on memory, the stressor or glucocorticoid is applied before stimulus presentation and learning, and recall is tested within 1–2 hr. In such a paradigm, cortisol levels are elevated during all memory phases: the learning period (initial encoding of the information), consolidation (the continuous transfer of information into longer term storage), and retrieval (recall of information from memory stores). Disruption of any one of these memory processes could account for detrimental effects of stress on memory and might also obscure any facilitated process. Roozendaal (2002) has theorized that under stressful conditions, consolidation of novel information related to the situation is enhanced so that one is more likely to later remember where the lion naps or when the hostile supervisor takes his coffee break. However, in order to facilitate this new learning during [Page 519] arousing situations, competing processes of retrieving old information (which could result in retroactive interference) may be inhibited. Thus, it may be impaired retrieval that accounts for many of the human findings cited above, rather than stress effects on learning or consolidation. Indeed, recent studies that have managed to isolate consolidation as a target process point to a facilitative effect of stress. These investigations typically administer the stress induction or corticosteroids prior to or immediately following training (during encoding and consolidation), followed by retention testing at least 24 hr later. Retrieval is therefore tested after corticosterone levels have returned to baseline, thereby isolating the effect of glucocorticoids on consolidation of new memories. Animal studies using this paradigm have generally found a facilitative effect of moderate levels of glucocorticoids on consolidation (Conrad, Lupien, & McEwen, 1999; Oitzl & de Kloet, 1992; Roozendaal & McGaugh, 1996; Sandi, Loscertales, & Guaza, 1997). Several recent human studies have also found a facilitative effect of stress or administered cortisol on encoding and consolidation of visual information with affective content when recall is tested at least 24 hr after learning (Buchanan & Lovallo, 2001; Cahill, Gorski, & Le, 2003); an additional study found this for both emotionally arousing and neutral information (Abercrombie, Kalin, Thurow, Rosenkranz, & Davidson, 2003). Abercrombie, H. C., Kalin, N. H., Thurow, M. E., Rosenkranz, M. A., & Davidson, R. J. (2003). Cortisol variation in humans affects memory for emotionally laden and neutral information. Behavioral Neuroscience, 117, 505–516. Buchanan, T. W., & Lovallo, W. R. (2001). Enhanced memory for emotional material following stress-level cortisol treatment in humans. Psychoneuroendocrinology, 26, 307–317. Cahill, L., Gorski, L., & Le, K. (2003). Enhanced human memory consolidation with post-learning stress: Interaction with the degree of arousal at encoding. Learning & Memory, 10, 270–274. Conrad, C. D., Lupien, S. J., & McEwen, B. S. (1999). Support for a bimodal role for Type II adrenal steroid receptors in spatial memory. Neurobiology of Learning and Memory, 72, 39–46. Oitzl, M. S., & de Kloet, E. R. (1992). Selective corticosteroid antagonists modulate specific aspects of spatial orientation learning. Behavioral Neuroscience, 106, 62–71. Roozendaal, B. (2002). Stress and memory: Opposing effects of glucocorticoids on memory consolidation and memory retrieval. Neurobiology of Learning and Memory, 78, 578–595. Roozendaal, B., & McGaugh, J. L. (1996). Amygdaloid nuclei lesions differentially affect glucocorticoid-induced memory enhancement in an inhibitory avoidance task. Neurobiology of Learning and Memory, 65, 1–8. Sandi, C., Loscertales, M., & Guaza, C. (1997). Experience-dependent facilitating effect of corticosterone on spatial memory formation in the water maze. European Journal of Neuroscience, 9, 637–642. |
Although nearly identical (even with regard to the references) nothing has been marked as a citation. Beckner et al. are mentioned on the previous page, but without indication that the following page will be a copy from their paper. |
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Letzte Bearbeitung dieser Seite: durch Benutzer:Hindemith, Zeitstempel: 20140111094132