Recruitment and Consolidation of Cell Assemblies for Words by Way of Hebbian Learning and Competition in a Multi-Layer Neural Network.
Current cognitive theories postulate either localist representations of knowledge or fully overlapping, distributed ones. We use a connectionist model that closely replicates known anatomical properties of the cerebral cortex and neurophysiological principles to show that Hebbian learning in a multi-layer neural network leads to memory traces (cell assemblies) that are both distributed and anatomically distinct. Taking the example of word learning based on action-perception correlation, we document mechanisms underlying the emergence of these assemblies, especially (i) the recruitment of neurons and consolidation of connections defining the kernel of the assembly along with (ii) the pruning of the cell assembly's halo (consisting of very weakly connected cells). We found that, whereas a learning rule mapping covariance led to significant overlap and merging of assemblies, a neurobiologically grounded synaptic plasticity rule with fixed LTP/LTD thresholds produced minimal overlap and prevented merging, exhibiting competitive learning behaviour. Our results are discussed in light of current theories of language and memory. As simulations with neurobiologically realistic neural networks demonstrate here spontaneous emergence of lexical representations that are both cortically dispersed and anatomically distinct, both localist and distributed cognitive accounts receive partial support.
Garagnani
Max
M
Medical Research Council, Cognition and Brain Sciences Unit, 15, Chaucer Road, Cambridge CB2 7EF, UK.
Wennekers
Thomas
T
Pulvermüller
Friedemann
F
Brain Res Bull. 1999 Nov-Dec;50(5-6):437
10643472
Biol Cybern. 1982;46(1):27-39
6307398
J Cogn Neurosci. 2004 Jul-Aug;16(6):978-87
15298785
Proc Natl Acad Sci U S A. 2008 Nov 18;105(46):18035-40
19004769
Psychol Rev. 1996 Jan;103(1):56-115
8650300
Behav Brain Sci. 1999 Feb;22(1):1-38; discussion 38-75
11301520
Annu Rev Neurosci. 2001;24:139-66
11283308
Neuron. 2004 Sep 30;44(1):5-21
15450156
Neuroimage. 2001 Sep;14(3):607-16
11506534
Neural Comput. 2007 Apr;19(4):910-33
17348767
Nat Neurosci. 2004 Jul;7(7):701-2
15184903
Behav Brain Sci. 2000 Aug;23(4):443-67; discussion 467-512
11301541
Nature. 1990 Sep 6;347(6288):69-72
1975639
Neuron. 1990 Dec;5(6):745-56
2148486
Behav Brain Sci. 1999 Apr;22(2):253-79; discussion 280-336
11301524
Annu Rev Neurosci. 1998;21:149-86
9530495
Nat Neurosci. 1999 Dec;2(12):1131-6
10570492
J Neurosci. 1982 Jan;2(1):32-48
7054394
Neuroinformatics. 2005;3(3):197-221
16077159
Science. 2000 Oct 20;290(5491):533-6
11039938
Biol Cybern. 1976 Jul 30;23(3):121-34
974165
Cortex. 2006 May;42(4):563-76
16881267
Neuroimage. 1999 Jan;9(1):18-45
9918726
Brain Lang. 2004 May;89(2):393-400
15068923
Eur J Neurosci. 2008 Jan;27(2):492-513
18215243
Psychol Rev. 2004 Jan;111(1):205-35
14756594
Cogn Psychol. 1986 Jan;18(1):1-86
3753912
Science. 1999 Sep 17;285(5435):1870-4
10489359
Prog Neurobiol. 1992 Aug;39(2):209-28
1323860
Biol Cybern. 1976 Aug 30;23(4):187-202
963125
Psychol Rev. 1989 Oct;96(4):523-68
2798649
Psychol Rev. 1986 Jul;93(3):283-321
3749399
Proc Natl Acad Sci U S A. 1992 May 15;89(10):4363-7
1350090
Cereb Cortex. 1998 Jun;8(4):310-20
9651128
Kybernetik. 1973 Sep;13(2):55-80
4767470
Nature. 1998 Feb 26;391(6670):892-6
9495341
J Neurosci. 2000 Apr 1;20(7):2451-8
10729325
Neuropsychologia. 2003;41(8):989-94
12667534
Trends Neurosci. 1993 Nov;16(11):480-7
7507622
Eur J Neurosci. 2002 Jul;16(2):291-310
12169111
Brain Lang. 2006 Mar;96(3):280-301
16040108
Vision Res. 1997 Dec;37(23):3339-42
9425548
Eur J Neurosci. 2002 Jan;15(2):399-402
11849307
Proc Natl Acad Sci U S A. 1999 Jun 22;96(13):7592-7
10377460
Proc Natl Acad Sci U S A. 2006 May 16;103(20):7865-70
16682637
Synapse. 1992 Sep;12(1):82-5
1357766
J Cogn Neurosci. 2004 May;16(4):683-701
15165356
Prog Neurobiol. 2006 May;79(1):49-71
16814448
Neuroimage. 2005 Feb 1;24(3):656-66
15652301
Cereb Cortex. 2002 Apr;12(4):339-48
11884349
Trends Neurosci. 1996 Apr;19(4):126-30
8658594
Science. 1996 Nov 15;274(5290):1133-8
8895456
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Feb;61(2):1855-74
11046472
J Cogn Neurosci. 1996 Winter;8(1):69-77
23972236
Neuroimage. 2003 Nov;20(3):1743-55
14642484
Nature. 1996 Jun 6;381(6582):526-8
8632826
Ann Neurol. 2005 Jan;57(1):8-16
15597383
Cereb Cortex. 1996 Jan-Feb;6(1):21-30
8670635
Nat Rev Neurosci. 2005 May;6(5):399-407
15861182
Cognition. 1980 Mar;8(1):1-71
7363578
Neuron. 1996 Sep;17(3):371-4
8816700
Nat Neurosci. 2000 Sep;3(9):919-26
10966623
J Exp Psychol Gen. 1985 Jun;114(2):159-97
3159828
Neural Comput. 2003 Jul;15(7):1511-23
12816564
J Math Biol. 1977 Oct 20;4(4):303-21
925522
Neuroimage. 2004 Apr;21(4):1701-20
15050592
Nature. 1989 May 18;339(6221):215-8
2716848
Nat Rev Neurosci. 2004 Feb;5(2):97-107
14735113
J Neurosci. 1983 May;3(5):1116-33
6188819
Neuron. 1995 Jul;15(1):1-4
7619513