Journal of Comparative Physiology A

, Volume 155, Issue 2, pp 263–270 | Cite as

A neural coding model for sensory intensity discrimination, to be applied to gustation

  • Frans W. Maes
Article

Summary

This paper presents a model of the neural coding and discrimination of sensory intensity. The model consists of five stages: (1) the coding of stimulus intensity in peripheral receptors or neurons by a ‘rate’ code. The relevance of comparing different analysis intervals for the response is pointed out; (2) neural processing, according to either ‘labeled-line’ or ‘across-fiber pattern’ theory. In addition, two possible non-linearities in the processing are considered: a threshold mechanism, and ‘contrast enhancement’ by reciprocal inhibition; (3) a neural discriminator, based on signal-detection theory; (4) a memory stage; (5) an effector organ providing a behavioral output. Emphasis is put on stages 2 and 3.

The model produces predictions of the differential threshold, which should be directly testable in a behavioral two-alternative forced-choice paradigm. The model will be applied to gustatory intensity discrimination in rat in a subsequent study (Maes and Erickson 1984). The Discussion pays attention to the relative contributions of peripheral and central “noise” sources. It also compares the present model with Beidler's (1958) approach through just noticeable differences (JND's). The model presented here seems more adequate in providing an understanding of sensory information processing.

Keywords

Stimulus Intensity Analysis Interval Differential Threshold Effector Organ Neural Code 

Abbreviations

AFP

across fiber pattern

DA

discrimination acuity

DT

differential threshold

JND

just noticeable difference

LL

labeled line

NTS

nucleus tractus solitarius

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Beidler LM (1954) A theory of taste stimulation. J Gen Physiol 38:133–139Google Scholar
  2. Beidler LM (1958) The physiological basis of taste psychophysics. Office of Naval Res Symp Report ACR-30; 1–11Google Scholar
  3. Den Otter CJ (1977) Single sensillum responses in the male mothAdoxophyes orana (F.v.R.) to female sex pheromone components and their geometrical isomers. J Comp Physiol 121:205–222Google Scholar
  4. Dethier VG (1976) The hungry fly. Harvard University Press, Cambridge, MassachusettsGoogle Scholar
  5. Eijkman E, Vendrik AJH (1963) Detection theory applied to the absolute sensitivity of sensory systems. Biophys J 3:65–78Google Scholar
  6. Ganchrow JR, Erickson RP (1970) Neural correlates of gustatory intensity and quality. J Neurophysiol 33:768–783Google Scholar
  7. Green DM, Swets JA (1966) Signal detection theory and psychophysics. John Wiley Sons, New YorkGoogle Scholar
  8. Halpern BP, Nelson LM (1965) Bulbar gustatory responses to anterior and posterior tongue stimulation in the rat. Am J Physiol 209:105–110Google Scholar
  9. Johnson KO (1980a) Sensory discrimination: Decision process. J Neurophysiol 43:1771–1792Google Scholar
  10. Johnson KO (1980b) Sensory discrimination: Neural processes preceding discrimination decision. J Neurophysiol 43:1793–1815Google Scholar
  11. Maes FW (1980) Neural coding of salt taste quality in blowfly labellar taste organ. In: Van der Starre H (ed) Olfaction and taste, vol 7. IRL Press Ltd, London, pp 123–126Google Scholar
  12. Maes FW, Bijpost SCA (1979) Classical conditioning reveals discrimination of salt taste quality in the blowflyCalliphora vicina. J Comp Physiol 133:53–62Google Scholar
  13. Maes FW, Erickson RP (1984) Gustatory intensity discrimination in rat NTS: a tool for the evaluation of neural coding theories. J Comp Physiol A 155:271–282Google Scholar
  14. Miller GA (1956) The magical number seven plus or minus two: some limits on our capacity for processing information. Psychol Rev 63:81–97Google Scholar
  15. Norgren R, Pfaffmann C (1975) The pontine taste area in the rat. Brain Res 91:99–117Google Scholar
  16. Ogawa H, Sato M, Yamashita S (1973) Variability in impulse discharges in rat chorda tympani fibers in response to repeated gustatory stimulations. Physiol Behav 11:469–479Google Scholar
  17. O'Mahony M (1972) Salt taste sensitivity: A signal detection approach. Perception 1:459–464Google Scholar
  18. Perkel DH, Bullock TH (1969) Neural coding. Neurosci Res Symp Summ 3:405–527Google Scholar
  19. Scott TR, Perrotto RS (1980) Intensity coding in pontine taste area: Gustatory information is processed similarly throughout rat's brain stem. J Neurophysiol 44:739–750Google Scholar
  20. Slotnick BM (1982) Sodium chloride detection threshold in the rat determined using a simple opérant discrimination task. Physiol Behav 28:707–710Google Scholar
  21. Smith DV (1971) Taste intensity as a function of area and concentration: Differentiation between compounds. J Exp Psychol 87:163–171Google Scholar
  22. Somjen G (1972) Sensory coding in the mammalian nervous system. Appleton-Century-Crofts, New YorkGoogle Scholar
  23. Thurstone LL (1927) A law of comparative judgment. Psychol Rev 34:273–286Google Scholar
  24. Uttal WR (1973) The psychobiology of sensory coding. Harper and Row, New YorkGoogle Scholar
  25. Von Békésy G (1967) Sensory inhibition. Princeton University Press, Princeton NJGoogle Scholar
  26. Wasserman GS (1981)Limulus psychophysics: Increment threshold. Percept Psychophys 29:251–260Google Scholar
  27. Werner G, Mountcastle VB (1965) Neural activity in mechano-receptive cutaneous afferents: Stimulus-response relations, Weber functions, and information transmission. J Neurophysiol 28:359–397Google Scholar
  28. Wong F, Knight BW, Dodge FA (1982) Adapting bump model for ventral photoreceptors ofLimulus. J Gen Physiol 79:1089–1113Google Scholar
  29. Yamamoto T, Kato T, Matsuo R, Araie N, Azuma S, Kawamura Y (1982) Gustatory reaction time under variable stimulus parameters in human adults. Physiol Behav 29:79–84Google Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Frans W. Maes
    • 1
  1. 1.Department of Animal PhysiologyState University at GroningenAA HarenThe Netherlands

Personalised recommendations