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Unequal but Fair? Weights in the Serial Integration of Haptic Texture Information

  • Alexandra Lezkan
  • Knut Drewing
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8618)

Abstract

The sense of touch is characterized by its sequential nature. In texture perception, enhanced spatio-temporal extension of exploration leads to better discrimination performance due to combination of repetitive information. We have previously shown that the gains from additional exploration are smaller than the Maximum Likelihood Estimation (MLE) model of an ideal observer would assume. Here we test if this suboptimal integration can be explained by unequal weighting of information. Participants stroke 2 to 5 times across a virtual grating and judged the ridge period in a 2IFC task. We presented slightly discrepant period information in one of the strokes in the standard grating. Results show linearly decreasing weights of this information with spatio-temporal distance (number of intervening strokes) to the comparison grating. For each exploration extension (number of strokes) the stroke with the highest number of intervening strokes to the comparison was completely disregarded. The results are consistent with the notion that memory limitations are responsible for the unequal weights. This study raises the question if models of optimal integration should include memory decay as an additional source of variance and thus not expect equal weights.

Keywords

Psychophysics Texture Serial integration 

Notes

Acknowledgements

This work was supported by grants from the Deutsche Forschungsgemeinschaft (GRK 1901/1; TRR 135/1, A05).

References

  1. 1.
    Henriques, D.Y., Soechting, J.F.: Approaches to the study of haptic sensing. J. Neurophysiol. 93(6), 3036–3043 (2005)CrossRefGoogle Scholar
  2. 2.
    Drewing, K., Lezkan, A., Ludwig, S.: Texture discrimination in active touch: Effects of the extension of the exploration and their exploitation. In: World Haptics Conference (WHC), 2011 IEEE, pp. 215–220. IEEE (2011)Google Scholar
  3. 3.
    Ernst, M.O., Bülthoff, H.H.: Merging the senses into a robust percept. Trends Cogn. Sci. 8(4), 162–169 (2004)CrossRefGoogle Scholar
  4. 4.
    Giachritsis, C.D., Wing, A.M., Lovell, P.G.: The role of spatial integration in the perception of surface orientation with active touch. Atten. Percept. Psychophys. 71(7), 1628–1640 (2009)CrossRefGoogle Scholar
  5. 5.
    Louw, S., Kappers, A.M.L., Koenderink, J.J.: Haptic detection of sine-wave gratings. Perception 34(7), 869–885 (2005)CrossRefGoogle Scholar
  6. 6.
    Gescheider, G.A., Bolanowski, S.J., Pope, J.V., Verrillo, R.T.: A four-channel analysis of the tactile sensitivity of the fingertip: frequency selectivity, spatial summation, and temporal summation. Somatosens. Mot. Res. 19(2), 114–124 (2002)CrossRefGoogle Scholar
  7. 7.
    Luck, S.J., Vogel, E.K.: The capacity of visual working memory for features and conjunctions. Nature 390(6657), 279–328 (1997)CrossRefGoogle Scholar
  8. 8.
    Lau, S., O’Mahony, M., Rousseau, B.: Are three-sample tasks less sensitive than two-sample tasks? Memory effects in the testing of taste discrimination. Percept. Psychophys. 66(3), 464–474 (2004)CrossRefGoogle Scholar
  9. 9.
    Wichmann, F.A., Hill, N.J.: The psychometric function: I. Fitting, sampling, and goodness of fit. Percept. Psychophys. 63(8), 1293–1313 (2001)CrossRefGoogle Scholar
  10. 10.
    Gilson, E.Q., Baddeley, A.D.: Tactile short-term memory. Q. J. Exp. Psychol. 21(2), 180–184 (1969)CrossRefGoogle Scholar
  11. 11.
    Bancroft, T.D., Hockley, W.E., Servos, P.: Can vibrotactile working memory store multiple items? Neurosci. Lett. 514(1), 31–34 (2012)CrossRefGoogle Scholar
  12. 12.
    Jones, S.A., Fiehler, K., Henriques, D.Y.: A task-dependent effect of memory and hand-target on proprioceptive localization. Neuropsychologia 50(7), 1462–1470 (2012)CrossRefGoogle Scholar
  13. 13.
    Hollins, M., Bensmaïa, S.J.: The coding of roughness. Can. J. Exp. Psychol. (Revue canadienne de psychologie experimentale) 61(3), 184–195 (2007)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Justus-Liebig University GiessenGiessenGermany

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