Experimental Brain Research

, Volume 90, Issue 1, pp 40–46 | Cite as

Spatiotemporal characteristics of direction-selective neurons in the middle temporal visual area of the macaque monkeys

  • Akichika Mikami


In an attempt to elucidate the mechanisms of directional selectivity in the neurons of the middle temporal visual area (MT) of macaque monkeys, we presented small numbers of sequentially flashed stimuli with various temporal and spatial intervals within the receptive field (RF) of direction-selective MT neurons. Experiments were performed using awake macaque monkeys trained to fixate on a set of short stationary lines. Stimuli were presented on a CRT screen under computer control. In two-flash experiments, responses to a test flash presented in the center of the RF were examined following a conditioning flash presented in various locations within the RF. Inhibition in the null direction was observed in about 78% of MT neurons, while facilitation was relatively weak in this group of neurons. In most of these neurons, the ranges of temporal and spatial intervals that produced directional selectivity in two-flash experiments were within half the values and double the values, respectively of those in multi-flash experiments. In the remaining 22% of direction-selective MT neurons, several flashed stimuli were necessary to produce directional selectivity. Most of these neurons showed facilitation in the preferred direction. It appears that the inhibitory mechanisms in the null direction are sufficiently strong to be induced by a single conditioning flash whereas the facilitatory mechanisms are weaker and several stimuli are required for production of the direction-selective response.

Key words

Area MT Visual motion Spatial and temporal interaction Single neuron activities Rhesus monkey 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Barlow HB, Levick WR (1965) The mechanism of directionally selective units in rabbit's retina. J Physiol 178:477–504Google Scholar
  2. Bond HW, Ho P (1970) Solid miniature silver-silver chloride electrodes for chronic implantation. Electroenceph Clin Neurophysiol 28:206–208Google Scholar
  3. Dubner R, Zeki SM (1971) Response properties and receptive fields of cells in an anatomically defined region of the superior temporal sulcus. Brain Res 35:528–532Google Scholar
  4. Ganz L, Felder R (1984) Mechanism of directional selectivity in simple neurons of the cat's visual cortex analyzed with stationary flash sequences. J Neurophysiol 51:294–324Google Scholar
  5. Komatsu H, Wurtz RH (1989) Modulation of pursuit eye movements by stimulation of cortical areas MT and MST. J Neurophysiol 62:31–47Google Scholar
  6. Komatsu H, Wurtz RH (1988a) Relation of cortical area MT and MST to pursuit eye movements. I. Localization and visual properties of neurons. J Neurophysiol 60:580–603Google Scholar
  7. Komatsu H, Wurtz RH (1988b) Relation of cortical area MT and MST to pursuit eye movements. III. Interaction with full field visual stimulation. J Neurophysiol 60:621–644Google Scholar
  8. Maunsell JHR, Van Essen DC (1983) Functional properties of neurons in middle temporal visual area of the macaque monkey. I. Selectivity for stimulus direction speed and orientation. J Neurophysiol 49:1127–1147Google Scholar
  9. McKee SP, Welch L (1985) Sequential recruitment in the discrimination of velocity. J Opt Soc Am 2:243–251Google Scholar
  10. Mikami A, Newsome WT, Wurtz RH (1986a) Motion selectivity in macaque visual cortex. I. Mechanisms of direction and speed selectivity in extrastriate area MT. J Neurophysiol 55:1308–1327Google Scholar
  11. Mikami A, Newsome WT, Wurtz RH (1986b) Motion selectivity in macaque visual cortex. II. Spatiotemporal range of directional interactions in MT and V1. J Neurophysiol 55:1328–1339Google Scholar
  12. Mikami A (1986) Inhibition and facilitation of the direction selective MT neurons of the macaque monkeys tested by a small number of stimuli. Neurosci Res Suppl 3:186Google Scholar
  13. Nakayama K, Silverman GH (1984) Temporal and spatial characteristics of the upper displacement limit for motion in random dots. Vision Res 24:293–299Google Scholar
  14. Newsome WT, Pare EB (1988) A selective impairment of motion perception following lesions of the middle temporal visual area (MT). J Neurosci 8:2201–2211Google Scholar
  15. Newsome WT, Britten KH, Movshon JA (1989) Neuronal correlates of a perceptual decision. Nature 341:52–54Google Scholar
  16. Newsome WT, Mikami A, Wurtz RH (1986) Motion selectivity in macaque visual cortex. III. Psychophysics and physiology of apparent motion. J Neurophysiol 55:1340–1351Google Scholar
  17. Newsome WT, Wurtz RH, Dursteler MR, Mikami A (1985) Deficits in visual motion processing following ibotenic acid lesions of extrastriate area MT of the macaque monkey. J Neurosci 5:825–840Google Scholar
  18. Saito HK, Tanaka K, Isono H, Yasuda M, Mikami A (1989) Direction selective response of cells in the middle temporal area (MT) of the macaque monkey to the movement of equiluminous opponent color stimuli. Exp Brain Res 75:1–14Google Scholar
  19. Wurtz RH (1969) Response of striate cortex neurons to stimuli during rapid eye movements in the monkey. J Neurophysiol 32:975–986Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Akichika Mikami
    • 1
  1. 1.Department of Neurophysiology, Primate Research InstituteKyoto UniversityInuyamaJapan

Personalised recommendations