Popovic M., Lisitsyn D., Berkes P., Lengyel M. & Fiser J. (2011) Uncertainty representation of low-level visual attributes. VSS 2011, Journal of Vision 11 (11), 807-807 [Abstract]
There is increasing behavioral evidence that humans represent uncertainty about sensory stimuli in a way that it is suitable for decision making and learning in a statistically optimal manner. Do such representations of uncertainty exist for low-level visual stimuli, and furthermore, are they probabilistic in nature? We tested whether subjective assessment of the orientation uncertainty […]
Galperin H., Bex P. & Fiser J. (2009) Orientation integration in complex visual processing. VSS 2009, Journal of Vision 9 (8), 1020-1020a [Abstract]
How does the visual system integrate local features to represent global object forms? Previously we quantified human orientation sensitivity in complex natural images and found that orientation is encoded only with limited precision defined by an internal threshold that is set by predictability of the stimulus (VSS 2007). Here we tested the generality of this […]
White BL. & Fiser J (2007) The effect of anesthesia on neural activity in the primary visual cortex of the rat. SFN 2007, San Diego, CA [Abstract]
Much of what we know about visual processing in the brain is based on neural data collected in anesthetized animals assuming that the essential aspects of the computations are preserved under such conditions. However, recent findings support an alternative view on visual perception that puts a strong emphasis on the role of ongoing activity which […]
Fiser J., Savin C., Berkes P., Chiu C. & Lengyel, M. (2012) Visual experience drives the increase in similarity between spontaneous and stimulus evoked activity in V1. SFN 2012, New Orleans, LA [Abstract]
Despite ample behavioral evidence for probabilistic learning in the brain, the neural underpinnings of this process remain unclear. It has been recently hypothesized that spontaneous activity in primary sensory areas could be a marker for this learning process (Fiser et al, 2010). In this view, the increase in similarity between spontaneous and stimulus-evoked activity over […]
Fiser J., Orbán G. & Lengyel M. (2011) Uncertainty in scene segmentation: statistically optimal effects on learning visual representations. VSS 2011, Journal of Vision 11 (11), 994-994 [Abstract]
A number of recent psychophysical studies have argued that human behavioral processing of sensory inputs is best captured by probabilistic computations. Due to conflicting cues, real scenes are ambiguous and support multiple hypotheses of scene interpretation, which require handling uncertainty. The effects of this inherent perceptual uncertainty have been well-characterized on immediate perceptual decisions, but […]
Cui M., Orban G., Lengyel M. & Fiser J. (2009) What eye-movements tell us about online learning of the structure of scenes. VSS 2009, Journal of Vision 9 (8), 389-389 [Abstract]
We have recently proposed that representations of novel multi-element visual displays learned and stored in visual long-term memory encode the independent chunks of the underlying structure of the scenes (Orban et al. 2008 PNAS). Here we tested the hypothesis that this internal representation guides eye movement as subjects explore such displays in a memory task. […]
Orbán G., Fiser J, Aslin RN. & Lengyel M. (2007) Do we develop visual representations based on pair-wise statistics of the visual scene? Sloan-Swartz Meeting of Theoretical Neurobiology 2007, San Diego, CA [Abstract]
The dominant view on how humans develop new visual representations is based on the paradigm of iterative associative learning. According to this account, new features are developed based on the strength of the pair-wise correlations between sub-elements, and complex features are learned by recursively associating already obtained features. In addition, Hebbian mechanisms of synaptic plasticity […]
Savin C., Berkes P., Chiu C., Fiser J. & Lengyel M. (2012) Similarity between spontaneous and sensory-evoked activity does suggest learning in the cortex. SFN 2012, New Orleans, LA [Abstract]
Over development, spontaneous activity (SA) in primary visual cortex (V1) becomes increasingly similar to stimulus evoked activity (EA) (Berkes et al, Science 2011). This increasing similarity has been taken to reflect a progressive adaptation of the animal’s internal models to the statistics of the environment (Berkes et al, 2011). An alternative interpretation (Okun et al, […]
Selig G., Lisitsyn D., Bex P. & Fiser J. (2011) The diagnostic features used for recognizing faces under natural conditions. VSS 2011, Journal of Vision 11 (11), 614-614 [Abstract]
Classical studies of face perception have used stimulus sets with standardized pose, feature locations and extremely impoverished information content. It is unclear how the results of these studies translate to natural perception, where faces are typically encountered in a wide variety of viewpoints and conditions. To address this issue, we used a 2-AFC coherence paradigm, […]
Fiser J., Orbán G., Lengyel M. & Aslin R. (2009) Coarse-to-fine learning in scene perception: Bayes trumps Hebb. VSS 2009, Journal of Vision 9 (8), 865-865 [Abstract]
Recent studies suggest that the coherent structures learned from multi-element visual scenes and represented in human memory can be best captured by Bayesian model comparison rather than by traditional iterative pair-wise associative learning. These two learning mechanisms are polar opposites in how their internal representation emerges. The Bayesian method favors the simplest model until additional […]