1.
Marklund, Niklas, et al.
(författare)
Neurokirurgisk omvårdnad
2024. - 1
Ingår i: Neurokirurgi. - : Studentlitteratur AB. - 9789144161532 ; , s. 285-296
Bokkapitel (populärvet., debatt m.m.)
2.
Alstermark, Bror, et al.
(författare)
Anders Lundberg (1920-2009)
2010
Ingår i: Experimental Brain Research. - : Springer. - 0014-4819 .- 1432-1106. ; 200:3-4, s. 193-195
Tidskriftsartikel (populärvet., debatt m.m.) abstract
Anders Lundberg was one of the founding editorial board members for EBR when it began its life in 1976 under the editorship of John Eccles. He was also one of the most prolific contributors to the journal with a total of 49 papers, including a series of 16 on the topic of "integration in descending motor pathways controlling the forelimb in the cat". He continued as an editor of the journal until volume 16 when he persuaded his younger colleague Hans Hultborn to take his place. Hans is one of the authors of the obituary. –John Rothwell
3.
Madison, Guy, et al.
(författare)
Human sensorimotor tracking of continuous subliminal deviations from isochrony
2004
Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940. ; 370, s. 69-73
Tidskriftsartikel (populärvet., debatt m.m.) abstract
We show that people continuously react to time perturbations in the range 3-96 ms in otherwise isochronous sound sequences. Musically trained and untrained participants were asked to synchronise with a sequence of sounds, and these two groups performed almost equally below the threshold for conscious detection of the deviations. Above this threshold the motor reactions accounted for a larger proportion of the stimulus deviations for musically trained participants.
4.
Mathiesen, Tiit, et al.
(författare)
Övriga benigna hjärntumörer
2024. - 1
Ingår i: Neurokirurgi. - 9789144161532 ; , s. 205-212
Bokkapitel (populärvet., debatt m.m.)
5.
Svensdotter, Emma, et al.
(författare)
Spinala tumörer
2024. - 1
Ingår i: Neurokirurgi. - 9789144161532 ; , s. 213-220
Bokkapitel (populärvet., debatt m.m.)
6.
Mathiesen, Tiit, et al.
(författare)
Pediatrisk neurokirurgi
2024. - 1
Ingår i: Neurokirurgi. - 9789144161532 ; , s. 271-284
Bokkapitel (populärvet., debatt m.m.)
7.
Tyrcha, Joanna, et al.
(författare)
Spike pattern distributions in model cortical networks
2008
Ingår i: COSYNE-Computational and Systems Neuroscience 2008, Salt Lake City.
Konferensbidrag (populärvet., debatt m.m.) abstract
We can learn something about coding in large populations of neurons from models of the spike pattern distributions constructed from data. In our work, we do this for data generated from computational models of local cortical networks. This permits us to explore how features of the neuronal and synaptic properties of the network are related to those of the spike pattern distribution model. We employ the approach of Schneidman et al [1] and model this distribution by a Sherrington-Kirkpatrick (SK) model: P[S] = Z-1exp(½ΣijJijSiSj+ΣihiSi). In the work reported here, we analyze spike records from a simple model of a cortical column in a high-conductance state for two different cases: one with stationary tonic firing and the other with a rapidly time-varying input that produces rapid variations in firing rates. The average cross-correlation coefficient in the former is an order of magnitude smaller than that in the latter.To estimate the parameters Jij and hi we use a technique [2] based on inversion of the Thouless-Anderson-Palmer equations from spin glass theory. We have performed these fits for groups of neurons of sizes from 12 to 200 for tonic firing and from 6 to 800 for the case of the rapidly time-varying “stimulus”. The first two figures show that the distributions of Jij’s in the two cases are quite similar, both growing slightly narrower with increasing N. They are also qualitatively similar to those found by Schneidman et al and by Tkačik et al [3] for data from retinal networks. As in their work, it does not appear to be necessary to include higher order couplings. The means, which are much smaller than the standard deviations, also decrease with N, and the one for tonic firing is less than half that for the stimulus-driven network.However, the models obtained never appear to be in a spin glass phase for any of the sizes studied, in contrast to the finding of Tkačik et al, who reported spin glass behaviour at N=120. This is shown in the third figure panel. The x axis is 1/J, where J = N1/2std(Jij) and the y axis is H/J, where H is the total “field” N-1Σi(hi+ΣjJij‹Sj›). The green curve marks the Almeida-Thouless line separating the normal and spin glass phases in this parameter plane. All our data, for N ≤800 (the number of excitatory neurons in the originally-simulated network), lie in the normal region, and extrapolation from our results predicts spin glass behaviour only for N>5000.[1] E. Schneidman et al., Nature 440 1007-1012 (2006)[2] T. Tanaka, Phys Rev E 58 2302-2310 (1998); H. J. Kappen and F. B Rodriguez, Neural Comp 10 1137-1156 (1998)[3] G. Tkačik et al., arXiv:q-bio.NC/0611072 v1 (2006)
8.
Tyrcha, Joanna, et al.
(författare)
Testing Algorithms for Extracting Functional Connectivity from Spike Data
2008
Ingår i: 1st INCF Congress of Neuroinformatics: Databasing and Modeling the Brain.
Konferensbidrag (populärvet., debatt m.m.) abstract
We can learn something about how large neuronal networks function from models of their spike pattern distributions constructed from data. We do this using the approach introduced by Schneidman et al [1], modeling this distribution by an Ising model: P[S] = Z-1exp(ΣJijSiSj + ΣihiSi). In the work reported here, we explore the accuracy of two algorithms for extracting the model parameters Jij and hi by testing them on data generated by networks in which these parameters are known.Both algorithms use, as input, the firing rates and mutual correlations of the neurons in the network. The first algorithm is straightforward Boltzmann learning. It will yield the parameters correctly if the input statistics are known exactly,but it may be very slow to converge. The second, very fast, algorithm [2] is based on inversion of the Thouless-Anderson-Palmer equations from spin glass theory. It is derived from a small-Jij expansion, but it is in principle correct for all Jij when the network is infinitely large and densely connected.In practice, however, the rates and correlations used as inputs to the algorithms are estimates based on a finite number of measurements. Therefore, there will be errors in the extracted model parameters. Errors will also occur if the data are incomplete, i.e., if the rates and correlations are not measured for all neurons or all pairs. This case is highly relevant to the experimental situation, since in practice it is only possible to record from a small fraction of the neurons in a network.Two particular kinds of error statistics are of special interest: variances of the differences between true and extracted parameters, and variances of the differences between parameters extracted for two independent sets of training data. We study the relation between the two, since the first is what we are interested in but only the second can be computed in the realistic situation, where we do not know the parameters a priori. We also examine the variance of the difference between the true and extracted correlations.Finally, we apply the algorithms to the data of Schneidman et al from salamander retinal ganglion neurons.References--------------------------------------------------------------------------------1. E Schneidman et al, Nature 440 1007-1012 (2006); G Tkacik et al, arXiv:q-bio.NC/0611072 (2006)2. T Tanaka, Phys Rev E 58 2302-2310 (1998); H J Kappen and F B Rodriguez, Neural Comp 10 1137-1156 (1998)
9.
Hjortdal, Anna, et al.
(författare)
Stødet : En vejviser i talestrømmen
2022
Ingår i: Sprog og Samfund. - 0108-433X. ; :4, s. 14-15
Tidskriftsartikel (populärvet., debatt m.m.) abstract
Abstract in DanishLyttere kan bruge stød og ikke-stød på ordstammer til at forudsige de grammatiske endelser, som følger efter.
10.
Lindgren, Stefan, et al.
(författare)
Utbildning utan lottning
2006
Ingår i: Sydsvenskan. - 1652-814X.
Tidskriftsartikel (populärvet., debatt m.m.) abstract
Det är trångt i kön till läkarutbildningen. Därför har Lunds universitet beslutat att utgå från skolbetyg vid antagning till utbildningen och att använda högskoleprovresultat som skiljekriterium vid lika meriter. Det skriver Stefan Lindgren, programdirektör, Lena Sandberg, nämndsekreterare, och Nils Danielsen, ordförande för läkarprogrammet vid Lunds universitet.
