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Single unit activity in the auditory cortex of a monkey performing a short term memory task


Short term memory to tones (STMT) was investigated by recording single unit activity in the auditory cortex of a behaving monkey. The activity of each unit was studied in two behavioral conditions: a) During task performance, the monkey had to compare two tones separated by one second of silence (inter-stimulus interval), b) During a nonperforming period; the monkey heard the two tones but did not respond behaviorally. It was noted that the firing rate of many units during the inter-stimulus interval (ISI) was dependent on the frequency of the first tone. Such dependency was observed even towards the end of the ISI, both during task performance trials (50% of the units) and during the nonperforming period (32% of the units). The activity of these units could be the basis of STMT in both of these behavioral states. In 65% of all the units tested, the responses during the ISI were of a higher magnitude in the performance period than were the responses in the non-performance period. The activity of these units may be related either to general processes such as attention and expectation or to short-term memory processes. During task performance, the responses of 23% of the units to the second tone were dependent on whether its frequency was identical to that of the first tone. Such dependency was never observed during the non-performing period. These units may detect similarity or non similarity between two tones presented one second apart. Periodic patterns of firing were not found in the study, thus suggesting that the ISI responses were not generated by reverberatory activity in simple closed loops. On the basis of these results, several alternative mechanisms of STMT are suggested.

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  1. Abeles M (1982) Quantification, smoothing, and confidence limits for single-units' histograms. J Neurosci Methods 5: 317–325

  2. Abeles M, Goldstein MH Jr (1977) Multispike train analysis. Proc IEEE 65: 762–773

  3. Beaton R, Miller J (1975) Single cell activity in the auditory cortex of the unanesthetized, behaving monkey: correlation with stimulus controlled behavior. Brain Res 100: 543–562

  4. Benson DA, Hienz RD (1978) Single unit in the auditory cortex of monkeys selectively attending left vs. right ear stimuli. Brain Res 159: 307–320

  5. Chorazyna H, Stepien L (1961) Impairment of auditory recent memory produced by cortical lesions in dogs. Acta Biol Exp 21: 177–187

  6. Eriksen CW, Johnson HJ (1964) Storage and decay characteristics of non attended auditory stimuli. J Exp Psychol 68: 28–36

  7. Frostig DR, Gottlieb Y, Vaadia E, Abeles M (1983) The effect of stimuli on the activity and functional connectivity of local neuronal group in the cat auditory cortex. Brain Res 272: 211–221

  8. Fuster JM (1973) Unit activity of pre-frontal cortex during delayed-response performance: neuronal correlates of transient memory. J Neurophysiol 36: 61–78

  9. Fuster JM, Alexander G (1971) Neuron activity related to shortterm memory. Science 173: 652–654

  10. Fuster JM, Jervey JA (1981) Inferiotemporal neurons distinguish and retain behaviourally relevant features of the visual stimuli. Science 212: 952–955

  11. Georgopoulos AP, Schwartz AB, Kettner RE (1986) Neuronal population coding of movment direction. Science 233: 1416–1419

  12. Goldstein MH Jr, Abeles M (1975) Single unit activity of the auditory cortex. In: Keidel DW, Neff WD (eds) Handbook of sensory physiology, Vol V(2). Springer, Berlin Heidelberg New York, pp 199–218

  13. Hebb DO (1949) The organisation of behavior: a neuropsychological theory. Wiley, New York

  14. Hocherman S, Benson DA, Goldstein MH Jr, Heffner HE, Hienz RD (1976) Evoked unit activity in auditory cortex of monkeys performing selective attention task. Brain Res 117: 51–68

  15. Horn G (1967) Neuronal mechanisms of habituation. Nature 215: 707

  16. John ER (1967) Mechanisms of memory. Academic Press. New York

  17. Kitzes LM, Farley GR, Starr A (1978) Modulation of auditory cortex units activity during performance of conditioned response. Exp Neurol 62: 678–697

  18. Komatsu H (1982) Prefrontal unit activity during color discrimination task with GO and NO-GO responses in the monkey. Brain Res 244: 269–277

  19. Kubota K (1975) Prefrontal unit activity during delayed response and delayed-alternation performances. Jpn J Physiol 25: 481–493

  20. Kubota K, Niki H (1971) Prefrontal cortical unit activity and delayed alternation performance in monkeys. J Neurophysiol 34: 337–347

  21. Kubota K, Tonoike M, Mikami A (1980) Neuronal activity in the monkey dorsolateral prefrontal cortex during discrimination task with delay. Brain Res 183: 29–42

  22. Lorente de Nó R (1949) Cerebral cortex: architecture, intracortical connections, motor projections. In: Fulton JF (ed) Physiology of the nervous system, 3rd edn. Oxford University Press, New York, pp 288–330

  23. Massaro OW, Kahn BJ (1973) Effects of central processing in auditory recognition. J Exp Psychol 97: 51–58

  24. Mauritz K-H, Wise SP (1986) Premotor cortex of the rhesus monkey: neuronal activity in anticipation of predictable environmental events. Exp Brain Res 61: 229–244

  25. Mikami A, Kubota K (1980) Inferotemporal neuron activities and color discrimination with delay. Brain Res 182: 65–78

  26. Miller JM, Beaton RD, O'Connor T, Pfingst BE (1974) Response pattern complexity of auditory cells in the cortex of unanesthetized monkeys. Brain Res 69: 101–113

  27. Neff W, Diamond I, Cassedey J (1975) Behavioural studies of auditory discrimination: central nervous system. In: Keider WD, Neff D (eds) Handbook of sensory physiology, Vol V/2. Springer, Berlin Heidelberg New York, pp 307–400

  28. Niki H (1974a) Prefrontal unit activity during delayed alternation in the monkey. I. Relation to direction of response. Brain Res 68: 185–196

  29. Niki H (1974b) Differential activity of prefrontal units during right and left delayed response trials. Brain Res 70: 340–349

  30. Niki H, Watanabe M (1976) Prefrontal unit activity and delayed response relation to cue location versus direction of response. Brain Res 105: 79–88

  31. Perkel DH, Gerstein GL, Moore GP (1967) (i) Neuronal spike trains and stochastic point processes, (ii) Simultaneous spike trains. Biophys J 7: 419–440

  32. Pfingst BE, O'Connor TA (1980) A vertical stereotaxic approach to auditory cortex in the unanesthetized monkey. J Neurosci Methods 2: 22–45

  33. Sanides F (1972) Representation in the cerebral cortex and its lamination patterns. In: Bourne GH (ed) Structure and function of nervous tissue. Academic Press, New York, pp 329–453

  34. Stepien LS, Cordeau JP, Rasmussen T (1960) The effect of temporal lobe and hippocampal lesion on auditory and visual recent memory. Brain 83: 470–489

  35. Tanji J, Kurata K (1985) Contrasting neural activity in supplementary and precentral motor cortex of monkeys. I. Responses to instructions determining motor responses to forthcoming signals of different modalities. J Neurophysiol 53: 129–141

  36. Vaadia E, Abeles M (1978) Computer aided investigation of acquired sensory-motor association. Brain Theory News Lett 3: 148–151

  37. Vaadia E, Gottlieb Y, Abeles M (1982) Single unit activity related to sensorimotor association in auditory cortex of a monkey. J Neurophysiol 48: 1201–1213

  38. Verzeano M, Laufer M, Spear P, McDonald S (1970) The activity of neuronal networks in the thalamus of the monkey. In: Pribram KH, Broadbent DE (eds) Biology of memory. Academic Pres, New York London, pp 239–272

  39. Vinogradova OS, Semyonova TP, Konovalov VPh (1970) Trace phenomena in single neurons of hippocampus and mammillary bodies. In: Pribram KH, Broadbent DE (eds) Biology of memory. Academic Press, New York London, pp 191–222

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Correspondence to Y. Gottlieb.

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Gottlieb, Y., Vaadia, E. & Abeles, M. Single unit activity in the auditory cortex of a monkey performing a short term memory task. Exp Brain Res 74, 139–148 (1989). https://doi.org/10.1007/BF00248287

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Key words

  • Auditory cortex
  • Short term memory
  • Single unit recording
  • Behaving monkeys