title: The prefrontal cortex and oculomotor delayed response: a reconsideration of the "mnemonic scotoma".
abstract: The concept of the "mnemonic scotoma," a spatially circumscribed region of working memory impairment produced by unilateral lesions of the PFC, is central to the view that PFC is critical for the short-term retention of information. Presented here, however, are previously unpublished data that offer an alternative, nonmnemonic interpretation of this pattern of deficit. In their study, Wajima and Sawaguchi [Wajima, K., & Sawaguchi, T. The role of GABAergic inhibiton in suppressing perseverative responses in the monkey prefrontal cortex. Neuroscience Research, 50(Suppl. 1), P3-P317, 2004] applied the GABA(A) antagonist bicuculline methiodide unilaterally to the PFC of two monkeys while they performed an oculomotor delayed-response task. Consistent with previous studies, errors for the initial memory-guided saccade were markedly higher when the cued location fell into the region of the visual field affected by the infusion. These erroneous saccades tended to select an alternative target location (out of a possible 16) that had not been cued on that trial. By extending the analysis window, however, it was observed that the second, "corrective" saccade often acquired the location that had been cued on that trial. Further analysis of the erroneous initial saccades indicated that they tended to be directed to a location that had been relevant on the previous trial. Thus, the deficit was not one of "forgetting" the cued location. Rather, it was one of selecting between currently and previously relevant locations. These findings suggest a need for a reconsideration of the concept of the mnemonic scotoma, which in turn invites a reconsideration of functional interpretations of sustained neuronal activity in PFC.
authors.affiliation: Kobe University, Japan. tsujimoto@ruby.kobe-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsujimoto
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Postle
mesh_terms: D000818:Animals; D001288:Attention / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D017397:Prefrontal Cortex / Q000502:physiology*; D011930:Reaction Time
references.citation: J Neurophysiol. 1998 Jun;79(6):2919-40
references.pmid: 9636098
references.citation: J Neurosci. 2010 Nov 24;30(47):15801-10
references.pmid: 21106819
references.citation: Cereb Cortex. 2007 Sep;17 Suppl 1:i70-6
references.pmid: 17726005
references.citation: Exp Neurol. 1970 May;27(2):291-304
references.pmid: 4987453
references.citation: BMC Psychiatry. 2003 Jul 30;3:9
references.pmid: 12890293
references.citation: Cereb Cortex. 2008 Dec;18(12):2748-61
references.pmid: 18359779
references.citation: J Neurophysiol. 1994 Feb;71(2):515-28
references.pmid: 7909839
references.citation: Brain Res. 1982 Sep 23;248(1):43-9
references.pmid: 7127141
references.citation: Cereb Cortex. 2007 Sep;17 Suppl 1:i110-7
references.pmid: 17548802
references.citation: Trends Cogn Sci. 2010 Apr;14(4):172-9
references.pmid: 20171926
references.citation: J Neurophysiol. 2001 Oct;86(4):2041-53
references.pmid: 11600660
references.citation: Neuron. 1998 Dec;21(6):1399-407
references.pmid: 9883732
references.citation: Neurosci Res. 2001 Jan;39(1):123-31
references.pmid: 11164260
references.citation: J Neurophysiol. 1971 May;34(3):337-47
references.pmid: 4997822
references.citation: Brain Res. 2009 Jul 28;1282:103-13
references.pmid: 19501072
references.citation: Psychol Aging. 2000 Dec;15(4):671-83
references.pmid: 11144326
references.citation: Cogn Affect Behav Neurosci. 2004 Dec;4(4):528-39
references.pmid: 15849895
references.citation: Nat Neurosci. 2001 Mar;4(3):311-6
references.pmid: 11224549
references.citation: PLoS Biol. 2004 Nov;2(11):e365
references.pmid: 15510225
references.citation: Mem Cognit. 2000 Sep;28(6):1041-9
references.pmid: 11105530
references.citation: Neuron. 2009 Dec 10;64(5):730-43
references.pmid: 20005828
references.citation: Nat Neurosci. 2004 Apr;7(4):404-10
references.pmid: 15004564
references.citation: J Comp Physiol Psychol. 1976 Mar;90(3):293-302
references.pmid: 819472
references.citation: Cortex. 2007 Jan;43(1):38-52
references.pmid: 17334206
references.citation: J Neurosci. 2006 Jul 5;26(27):7305-16
references.pmid: 16822988
references.citation: Eur J Neurosci. 2002 Jul;16(2):291-310
references.pmid: 12169111
references.citation: Science. 1991 Feb 22;251(4996):947-50
references.pmid: 1825731
references.citation: Neuroscience. 2006 Apr 28;139(1):251-61
references.pmid: 16325345
references.citation: Science. 1971 Aug 13;173(3997):652-4
references.pmid: 4998337
references.citation: J Neurophysiol. 1989 Feb;61(2):331-49
references.pmid: 2918358
references.citation: Eur J Neurosci. 2004 Jan;19(2):447-57
references.pmid: 14725639
references.citation: J Neurophysiol. 2002 Jan;87(1):567-88
references.pmid: 11784772
references.citation: J Comp Physiol Psychol. 1969 Apr;67(4):535-46
references.pmid: 4977795
references.citation: Trends Neurosci. 2000 Oct;23(10):475-83
references.pmid: 11006464
references.citation: Neuropsychologia. 2002;40(3):349-56
references.pmid: 11684168
references.citation: Neuron. 1995 Mar;14(3):477-85
references.pmid: 7695894
references.citation: J Neurosci. 2011 Mar 16;31(11):3968-80
references.pmid: 21411640
references.citation: Annu Rev Neurosci. 2001;24:167-202
references.pmid: 11283309
references.citation: Science. 1997 May 2;276(5313):821-4
references.pmid: 9115211
references.citation: Cereb Cortex. 2004 Dec;14(12):1328-39
references.pmid: 15166104
references.citation: J Comp Physiol Psychol. 1952 Dec;45(6):565-75
references.pmid: 13000029
references.citation: J Neurosci. 1993 Apr;13(4):1479-97
references.pmid: 8463830
references.citation: Nat Rev Neurosci. 2005 Apr;6(4):312-24
references.pmid: 15803162
references.citation: J Neurocytol. 2002 Mar-Jun;31(3-5):373-85
references.pmid: 12815254
references.citation: Neuron. 2009 Jul 30;63(2):244-53
references.pmid: 19640482
references.citation: J Neurosci. 2000 Jan 1;20(1):485-94
references.pmid: 10627624
references.citation: J Neurosci. 2011 Apr 27;31(17):6266-76
references.pmid: 21525266
references.citation: Mem Cognit. 2002 Sep;30(6):871-84
references.pmid: 12450091
references.citation: Cereb Cortex. 2011 Dec;21(12):2722-32
references.pmid: 21527786
references.citation: Science. 1969 Sep 19;165(3899):1271-3
references.pmid: 4979528