NOTE: THIS LIST IS IN PROGRESS (AT SNAIL'S PACE)...Ok, so I guess I haven't updated it in 7 years....

Synaptic weight change is all-or-none

O'conner, Wittenberg & Wang 2005 Graded bidirectional synaptic plasticity is composed of switch-like unitary events PNAS, July 5, 2005; 102(27): 9679 - 9684.


Uusitalo 1996 Increasing cell persistence from early to late cortices
Curtis, C.E. & D'Esposito, M. 2003 TICS 7(9) Persistent activity in the prefrontal cortex during working memory
Fuster & Alexander 1971 Delay activity in PFC. Activities up to about 20 sec. Hypothesized as correlate of 'working memory'.
Kubota & Niki 1971  
Erickson & Desimone 1999 "Responses of Macaque Perirhinal Neurons during and after Visual Stimulus Association Learning"
Egorov A. V., Hamam B. N., Fransén E., Hasselmo M. E. and Alonso A. A. (2002): Graded persistent activity in entorhinal cortex neurons. Nature: 420, 173-178 2002 ...graded persistent activity constitutes an elementary mechanism for working memory...
Wang, X-J. 2001 TINS 24(8) Synaptic reverberation underlying mnemonic persistent activity
M. W. HOWARD, T. E. YOUKER, V. S. VENKATADASS SFN 2006 The persistence of memory: temporally defined retrieval effects observed over hundreds of seconds.

Top-Down Modulation of Cortical Activity

Miyashita, Y. (2004) Science .306 Cognitive Memory: Cellular and Network Machineries and Their Top-Down Control
Fiser, J.   Ferret V1 activity modulated only slightly by ongoing sensory inputs. Consistent with the idea that much more of the modulation comes from horizontal and top-down influences.
Kuai et al.


Naure Neuroscience 8(11)

Perceptual learning studies showing that contrast and motion discrimination tasks that cannot be learned when the sequential stimuli are presented in random magnitude order (i.e., 'contrast roving' condition) can be learned when the stimuli are presented in increasing magnitude order. They hypothesize that the ordered condition allows an overlying code to remain active and abet the learning of the contrast whereas the roving condition causes multiple overlying codes to become active, thus causing decreased opportunity for learning.
Wolfart, Debay, Le Masson, Destexhe, Bal


Naure Neuroscience advance on-line pubs

TD cortical modulation of thalamic transfer function
Hans Supe`r, Henk Spekreijse, & Victor A. F. Lamme Science, 2001

"A Neural Correlate of Working Memory in the Monkey Primary Visual Cortex"

Shows task-dependent modulation of V1 cell activity for up to 2 seconds following of offset of the V1 cell. The authors attribute this to top-down (or, contextual) influence that is essentially a memory trace.

Hirata, A., Aguilar, J. & castro-Alamancos, M.A. 2006 J. Neuroscience 26(16) 4426-4436 Noradrenergic Activation Amplifies Bottom-Up and Top-Down Signal-to-Noise Ratios in Sensory Thalamus.
Summerfeld et al. (2006) PloS 2006 Neocortical Connectivity during Episodic Memory Formation

Delay Activity

Ninokura, Mushiake & Tanji 2004 Prefrontal activity encoding temporal order of visual objects.
Freedman, Poggio, Riesenhuber, Miller 2003

"A Comparison of Primate Prefrontal and Inferior Temporal Cortices during Visual Categorization"

Mongillo, Amit & Brunel 2003 Cerebral Cortex 13(11) 1139-1150

"Retrospective and prospective persistent activity inducedby Hebbian learning in a recurrent cortical network"

Describes a neural model that shows a transition from retrospective activity (of modelled PFC neurons) to prospective activity.

wang, x.j. The Journal of Neuroscience, November 1, 1999, 19(21):9587-9603 "Synaptic Basis of Cortical Persistent Activity: the Importance of NMDA Receptors to Working Memory"

Perception is Discrete

VanRullen, R.    
Henderson & Hollingworth 1999  

Memory activity recapitulates encoding activity

Sirota, A., Csicsvari, J., Buhl, D. & Buzsaki, J. 2003 PNAS 100(4) Communication between neocortex and hippocampus during sleep in rodents
Lee, A.K. & Wilson, M.A. 2002 Neuron 36 1183-1194 Memory of Sequential Experience in the Hippocampus during Slow Wave Sleep
Kali, S. & Dayan, P. 2004 Nature Neuroscience 7(3) Off-line replay maintains declarative memories in a model of hippocampal-neocortical interactions
D. JI, M. A. WILSON sfn 2006 Coordinated replay of awake experience in the cortex and hippocampus during slow-wave sleep

Stability of neural representations from inception

muller, kubie, bostock    
ikegaya et al. (Yuste lab) 2004, Science  

Sparseness of activity

Hahnloser et al.    
R. Quian, Quiroga, L. Reddy, G., Kreiman, C., Koch, & I. Fried Nature, 2005

"Invariant visual representation by single neurons in the human brain"

from Olshausen NIPS 2005 talk:


Evidence for sparse coding:

  • Gilles Laurent - mushroom body, insect
  • Michael Fee - HVC, zebra finch
  • Tony Zador - auditory cortex, mouse
  • Bill Skaggs - hippocampus, primate
  • Harvey Swadlow - motor cortex, rabbit
  • Michael Brecht - barrel cortex, rat
  • Jack Gallant - visual cortex, macaque monkey
  • Christof Koch/Itzhak Fried - inferotemportal cortex, human

Episodically-based memory

Palmeri, T.J.& Gauthier, I. 2004 Nature Reviews: Neuroscience 5(4) "Visual Object Understanding"
Weinberger, N.M. 2004 Nature Reviews: Neuroscience 5(4) SPECIFIC LONG-TERM MEMORY TRACES IN PRIMARY AUDITORY CORTEX
Whittlesea & Dorken 1989  
Vokey & Brooks    
Nosofsky & Cohen    
Tomasello 2000  


Mountcastle, V.B. 1957  
Mountcastle, V.B. 1997 Brain 120 701-722 The columnar organization of the neocortex
Mountcastle, V.B. 2003 Cerebral Cortex 13(1) Introduction
Jones, E.G. 2000 PNAS 97(10) 5019-5021 Microcolumns in the cerbral cortex

Cortical Microcircuit

Mayor, J. & Gerstner, W. 2005

"Noise-enhanced computation in a model of a cortical column"

Thomson, A.M. & Bannister, A.P. 2003 Cerebral Cortex 13(1) Intralaminar connections in the neocortex
Goodhill, G.J. & Carreira-Perpinan, M.A. 2002

Cortical Columns --in-- Encyclopedia of Cognitive Science, Macmillan.

Kalisman, N., Silberberg, G. & Markram, H. 2005 PNAS 102(3) The neocortical microcircuit as a tabula rasa.
Sun QQ, Huguenard JR, Prince DA.  

"Barrel cortex microcircuits: thalamocortical feedforward inhibition in spiny stellate cells is mediated by a small number of fast-spiking interneurons."

J Neurosci. 2006 Jan 25;26(4):1219-30

Zhu Y, Stornetta RL, Zhu JJ.  

"Chandelier cells control excessive cortical excitation: characteristics of whisker-evoked synaptic responses of layer 2/3 nonpyramidal and pyramidal neurons."

J Neurosci. 2004 Jun 2;24(22):5101-8.Click here to read

This article suggests that chandelier cells might subserve the general normalization of activity that is utilized in TEMECOR. The spread of a chandelier cell seems to be on the order of 400 microns. A minicolumn's width ~40-50 microns. It is possible that a single chandelier cell might implement the activity normalization for a macrocolumn (hypercolumn).


Abeles   Synfire chains

Neural representation of time and space may be linked

Eagleman, D. 2005 Nature Neuroscience 8(7)

Distortions of Time During Rapid Eye Movements


Spatiotemporal memory traces

Freidrich & Laurent 2001

Spatiotemporal olfactory codes in zebrafish

VanRullen, R.    
Beggs & Plenz 2004

Neuronal Avalanches Are Diverse and Precise Activity Patterns That Are Stable for Many Hours in Cortical Slice Cultures

The Journal of Neuroscience, June 2, 2004, 24(22):5216-5229

Brown, S.L., Joseph,, J, & Stopfer, M.


Naure Neuroscience 8(11)

"Encoding a temporally structured stimulus with a temporally structured neural representation" ...the title says it all...mapping ST input patterns into ST neural patterns...

Very cool article. They show that different odors lead to different trajectories through the ensemble projections-neuron representation space. The subset of cells representing the odor changes over short time during the representational period, i.e., odors, presented under four very different schedules, reliably map to the same spatiotemporal representation in the projection neurons population.

My notes on Graybiel (1998) discussing prior data (hikosaka) on SMA and pre-SMA cells sensitivity to sequential-order.    

Use of Noise to Aid Computation

Mayor, J. and Gerstner, W. Noise-enhanced computation in a model of a cortical column NeuroReport (2005) , 16 (11) : 1237--1240


Noise-enhanced computation in a model of a cortical column They discuss stochastic resonance, a phenomenon that, in the context of sensory systems, can improve recognition of weak signals. I don't see much of a relation between this concept of using noise to aid computation and the use of noise in TEMECOR.


Multiplicative Combination of Inputs

E. Salinas & L.F. Abbott. 1996 PNAS, 93:11956{11961)

A model of multiplicative neural responses in parietal cortex

Larkum, M.E., Zhu, J. & Sakmann, B. 1999 Nature 398 338-341 A new cellular mechanism for coupling inuts arriving at different cortical layers

Reduced Activity in Familiarity Condition vs. Novelty

J.P. Aggleton and M.W. Brown, Q. J. Exp. Psychol., B 58 (2005), pp. 218–233.

"Contrasting hippocampal and perirhinal cortex function using immediate early gene imaging"

TEMECOR's explanation of this general finding is as follows. When the input is unfamiliar, high noise is added into the winner selection process. In terms of the WTA operation of the minicolumn, this could be effected by making ALL the principal neurons (i.e., representing cells) of the minicolumn highly active, thus making them all approximately equally likely to win. This might be effected by a boost of Ach in the minicolumn.

In contrast, familiarity can occur only after prior learning has occurred. In this condition, low or zero noise is added (i.e., no squirt of Ach into the minicolumn). The result is that the single cell that won in the past, will rapidly become active and, via whatever the inhibitory circuitry of the minicolumn is, rapidly inhibit the rest of the minicolumn's cells. Thus, an overall, far smaller level of activity averaged over the cells of the minicolumn.


Distributed Coding

Staedtler, E. S., Pipa, G., Muckl, Goebel, F. R., Munk, M. H. sfn 2006 Dissimilarity of firing rate patterns suggest population coding of visual objects in prefrontal cortex during short-term memory