Motor command in the ventrolateral thalamic nucleus: Neuronal variability can be overcome by ensemble average (original) (raw)
Summary
The variability and stationarity of single unit activity and reaction times in a simple reaction time task were investigated by means of unit recordings from the ventrolateral thalamic nucleus in the cat. The study was carried out on eight neurons recorded over many trials and displaying an increase in activity correlated with the performed reaction time. The stationarity of the correlation appeared to be better than that of the unit activity or reaction time taken alone. In this stationary process the neuronal variability is considerable, and the investigator has to use time averages over many trials to be able to extract information from the single unit data. Since the nervous system does not require repeated presentations of a stimulus to trigger a movement, it must be using parallel processing of information through ensemble averages. A simulation of an ensemble average based upon the data from these eight neurons showed that such a process can be efficient. An evaluation of the number of neurons required to obtain a quasi deterministic neuronal command of the reaction time value, gave the speculative figure of 70. This figure could represent the dimension of the set of neurons with the same characteristics involved in the motor command.
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References
- Amalric M, Condé H, Dormont JF, Schmied A (1980) Unitary recording and cooling in the interposito-rubral system during a conditioned motor task, in the cat. Neurosci Lett [Suppl] 5: S438
Google Scholar - Bénita M, Condé H, Dormont JF, Schmied A (1979) Effects of cooling the thalamic ventrolateral nucleus of cats on a reaction time task. Exp Brain Res 34: 435–452
Google Scholar - Bullock TH (1980) Reassessment of neural connectivity and its specification. In: Pinsker HM, Willis WD, Jr (eds) Information processing in the nervous system. Raven Press, New York, pp 199–220
Google Scholar - Evarts EV (1966) Pyramidal tract activity associated with a conditioned hand movement in the monkey. J Neurophysiol 29: 1011–1027
Google Scholar - Heggelund P, Albus K (1978) Response variability and orientation discrimination of single cells in striate cortex of cat. Exp Brain Res 32: 197–211
Google Scholar - Humphrey DR, Schmidt EM, Thompson WD (1970) Predicting measures of motor performance from multiple cortical spike trains. Science 170: 758–762
Google Scholar - Hyvärinen J, Hyvärinen L, Linnankoski I (1981) Modification of parietal association cortex and functional blindness after binocular deprivation in young monkeys. Exp Brain Res 42: 1–8
Google Scholar - Lee YW (1966) Statistical theory of communication. Wiley, New York
Google Scholar - Moore GP, Perkel DH, Segundo JP (1966) Statistical analysis and functional interpretation of neuronal spike data. Ann Rev Physiol 28: 493–522
CAS PubMed Google Scholar - Mountcastle VB, Talbot WH, Sakata H, Hyvärinen J (1969) Cortical neuronal mechanisms in flutter-vibration studied in unanesthetized monkeys. Neuronal periodicity and frequency discrimination. J Neurophysiol 32: 452–484
Google Scholar - Perkel DH, Gerstein GL, Moore GP (1967) Neuronal spike trains and stochastic processes. I. The single spike train. Biophys J 7: 391–418
Google Scholar - Perkel DH, Bullock TH (1968) Neural coding. Neurosci Res Prog Bull 6: 226–343
Google Scholar - Rispal-Padel L (1979) Functional characteristics of the cerebello-thalamo-cortical pathway in the cat. In: Massion J, Sasaki K (eds) Cerebro-cerebellar interactions. Elsevier, Amsterdam, pp 67–103
Google Scholar - Rodieck RW, Kiang NYS, Gerstein GL (1962) Some quantitative methods for the study of spontaneous activity of single neurons. Biophys J 2: 351–358
Google Scholar - Rose D (1979) An analysis of the variability of unit activity in the cat's visual cortex. Exp Brain Res 37: 595–604
Google Scholar - Schmied A, Bénita M, Condé H, Dormont JF (1979) Activity of ventrolateral thalamic neurons in relation to a simple reaction time task in the cat. Exp Brain Res 36: 285–300
Google Scholar - Schreiner RC, Essick GK, Whitsel BL (1978) Variability in somatosensory cortical neuron discharge: Effects on capacity to signal different stimulus conditions using a mean rate code. J Neurophysiol 41: 338–349
Google Scholar - Stein RB (1970) The role of spike trains in transmitting and distorting sensory signals. In: Schmitt FO (ed) The neurosciences, second-study program. The Rockfeller University Press, New York, pp 597–604
Google Scholar - Werner G, Mountcastle VB (1963) The variability of central neural activity in a sensory system, and its implications for the central reflection of sensory events. J Neurophysiol 26: 958–977
Google Scholar
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- Laboratoire de Neurobiologie du Dévelopement, Université de Paris Sud, Bât. 440, F-91405, Orsay, France
J. F. Dormont, A. Schmied & H. Condé
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- J. F. Dormont
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Dormont, J.F., Schmied, A. & Condé, H. Motor command in the ventrolateral thalamic nucleus: Neuronal variability can be overcome by ensemble average.Exp Brain Res 48, 315–322 (1982). https://doi.org/10.1007/BF00238606
- Received: 21 December 1981
- Issue Date: December 1982
- DOI: https://doi.org/10.1007/BF00238606