Experimental Brain Research

, Volume 163, Issue 2, pp 239–241 | Cite as

Effect of visual noise on pattern recognition

  • Munetaka Shidara
  • Barry J. Richmond
Research Note


We recognize objects even when they are partially degraded by visual noise. Using monkeys performing a sequential delayed match-to-sample task, we studied the relation between the amount of visual noise (5, 10, 15, 20 or 25%) degrading the eight black and white stimuli used here, and the accuracy and speed with which matching stimuli were identified. The correct response rate decreased slightly as the amount of visual noise increased for both monkeys. Even at the 25% noise level, the correct response rate was more than 80%, indicating that the monkeys can recognize the pattern they are trying to match when the pattern is masked with visual noise. In contrast, the reaction time to the match stimulus increased substantially as the amount of visual noise increased. Thus, the monkeys appear to be trading time to maintain accuracy, suggesting that the monkeys are accumulating information and/or testing hypotheses about whether the test stimulus is likely to be a match for the sample being held in short-term memory.


Pattern recognition Visual noise Behavioral latency Rhesus monkey 



This work is supported by AIST/Japan and IRP/NIMH/USA.


  1. Bussey TJ, Saksida LM, Murray EA (2003) Impairments in visual discrimination after perirhinal cortex lesions: testing ‘declarative’ vs. ‘perceptual-mnemonic’ views of perirhinal cortex function. Eur J Neurosci 17:649–660Google Scholar
  2. Eskander EN, Richmond BJ, Optican LM (1992a) Role of inferior temporal neurons in visual memory I. Temporal encoding of information about visual images, recalled images, and behavioral context. J Neurophysiol 68:1277–1295Google Scholar
  3. Eskander EN, Richmond BJ, Optican LM (1992b) Role of inferior temporal neurons in visual memory II. Multiplying temporal waveforms related to vision and memory. J Neurophysiol 68:1296–1306Google Scholar
  4. Jones DG, Anderson ND, Murphy KM (2003) Orientation discrimination in visual noise using global and local stimuli. Vision Res 43:1223–1233Google Scholar
  5. Judge SJ, Richmond BJ, Chu FC (1980) Implantation of magnetic search coils for measuring eye position: an improved method. Vision Res 20:535–558CrossRefPubMedGoogle Scholar
  6. Logothetis NK, Sheinberg DL (1996) Visual object recognition. Ann Rev Neurosci 19:577–621Google Scholar
  7. Miyashita Y (1993) Inferior temporal cortex: where visual perception meets memory. Ann Rev Neurosci 16:245–263Google Scholar
  8. Richmond BJ, Optican LM (1987) Temporal encoding of two-dimensional patterns by single units in primate inferior temporal cortex. I. Response characterics. J Neurophysiol 57:132–146Google Scholar
  9. Robinson DA (1963) A method of measuring eye movements using a scleral search coil in a magnetic field. IEEE Trans Biomed Eng 10:137–145PubMedGoogle Scholar
  10. Ungerleider LG, Mishkin M (1982) Two cortical visual systems. In: Ingle DJ, Goodale MA, Mansfield RJW (eds) Analysis of visual behavior. MIT, Cambridge, MA, pp 549–586Google Scholar
  11. Wurtz RH (1969) Visual receptive fields of striate cortex neurons in awake monkeys. J Neurophysiol 32:727–742Google Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Neuroscience Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)Tsukuba, IbarakiJapan
  2. 2.Laboratory of NeuropsychologyNational Institute of Mental Health, NIH, DHHSBethesdaUSA

Personalised recommendations