Internally generated reactivation of single neurons in human hippocampus during free recall.
The emergence of memory, a trace of things past, into human consciousness is one of the greatest mysteries of the human mind. Whereas the neuronal basis of recognition memory can be probed experimentally in human and nonhuman primates, the study of free recall requires that the mind declare the occurrence of a recalled memory (an event intrinsic to the organism and invisible to an observer). Here, we report the activity of single neurons in the human hippocampus and surrounding areas when subjects first view cinematic episodes consisting of audiovisual sequences and again later when they freely recall these episodes. A subset of these neurons exhibited selective firing, which often persisted throughout and following specific episodes for as long as 12 seconds. Verbal reports of memories of these specific episodes at the time of free recall were preceded by selective reactivation of the same hippocampal and entorhinal cortex neurons. We suggest that this reactivation is an internally generated neuronal correlate for the subjective experience of spontaneous emergence of human recollection.
Gelbard-Sagiv
Hagar
H
Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel.
Mukamel
Roy
R
Harel
Michal
M
Malach
Rafael
R
Fried
Itzhak
I
D000200:Action Potentials; D001931:Brain Mapping; D003463:Cues; D004567:Electrodes, Implanted; D018728:Entorhinal Cortex / Q000502:physiology*; D004827:Epilepsy; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D011939:Mental Recall; D009474:Neurons / Q000502:physiology*
Science. 2008 Sep 5;321(5894):1322-7
18772431
Neuron. 1997 May;18(5):753-65
9182800
Trends Cogn Sci. 2008 Mar;12(3):87-91
18262826
Neuron. 1999 Feb;22(2):233-42
10069330
Nature. 2005 Jun 23;435(7045):1102-7
15973409
Proc Natl Acad Sci U S A. 2000 Sep 26;97(20):11120-4
11005878
Science. 2004 Oct 15;306(5695):435-40
15486288
J Cogn Neurosci. 2000 Nov;12(6):913-23
11177413
Nature. 2000 Nov 16;408(6810):357-61
11099042
Annu Rev Neurosci. 2004;27:279-306
15217334
Philos Trans R Soc Lond B Biol Sci. 1997 Nov 29;352(1362):1689-95
9415920
Nat Rev Neurosci. 2008 Mar;9(3):182-94
18270514
Nature. 1999 Feb 18;397(6720):613-6
10050854
Neuron. 2002 Dec 19;36(6):1183-94
12495631
Science. 2005 Dec 23;310(5756):1963-6
16373577
Nat Neurosci. 2002 May;5(5):458-62
11976705
Nature. 2006 Mar 30;440(7084):680-3
16474382
Neuron. 2006 Mar 16;49(6):805-13
16543129
Nat Neurosci. 2000 Sep;3(9):946-53
10966627
Brain Res. 1971 Nov;34(1):171-5
5124915
J Neurosci. 2004 Apr 28;24(17):4172-80
15115812
Science. 1996 Mar 29;271(5257):1870-3
8596957
J Cogn Neurosci. 2006 Oct;18(10):1654-62
17014370
J Neurosurg. 1999 Oct;91(4):697-705
10507396
Science. 1994 Jul 29;265(5172):676-9
8036517
Trends Cogn Sci. 2008 Jan;12(1):24-30
18069046
J Neurol Neurosurg Psychiatry. 1957 Feb;20(1):11-21
13406589
Nature. 1988 Jun 23;333(6175):773-5
3386719
Proc Natl Acad Sci U S A. 2000 Sep 26;97(20):11125-9
11005879
Curr Opin Neurobiol. 2006 Apr;16(2):179-90
16564688
Nat Neurosci. 2002 Jan;5(1):64-71
11753418
Nat Neurosci. 2007 Oct;10(10):1241-2
17828259
Neuron. 2004 Sep 30;44(1):109-20
15450164
J Neurosci. 2007 Nov 7;27(45):12176-89
17989284