Magas D., Koblinger Á., Lengyel M. & Fiser J. (2022) Reducible and irreducible uncertainty in low-level visual representations. VSS 2022 [Abstract]
Humans use their subjective uncertainty in their internal representations to make optimal decisions. However, perceptual uncertainty can have two components which have not been systematically distinguished or separately measured. Reducible uncertainty stemming from the noisiness of the system that can be modulated by external and internal factors such as contrast level or attention and that […]
Avarguès-Weber A., Finke V., Nagy M., Szabó T., Dyer A. & Fiser J. (2018) Visual Statistical Learning in Honeybees. ECVP 2018 [Abstract]
The ability of developing complex internal representations of the visual environment is crucial to the emergence of humans’ higher cognitive functions. Yet it is an open question whether there is any fundamental difference in how humans and other good visual learner species naturally encode aspects of novel visual scenes. We investigated how honeybees encode instinctively […]
Fiser J., Arato J., Khani A. & Rainer G. (2016) Change-related weighting of statistical information in visual decision making. VSS 2016, Journal of Vision 16 (12), 574-574 [Abstract]
There is a complex interaction between short- and long-term statistics of earlier percepts in modulating perceptual decisions, yet this interaction is not well understood. We conducted experiments, in which we independently manipulated the appearance probabilities (APs) of abstract shapes over short and long time ranges, and also tested the effect of dynamically changing these probabilities. […]
Haefner RM. & Fiser J. (2014) Good noise or bad noise? The role of correlated variability in a probabilistic inference framework. COSYNE 2014, Salt Lake City, UT [Abstract]
The responses of sensory neurons in cortex are variable, and this variability is often correlated [Cohen and Kohn, 2011]. While correlations were initially seen as primarily detrimental to the ability of neuronal populations to carry information about an external stimulus [Zohary et al., 1994], more recent studies have shown that they need not be information-limiting […]
Popovic M., Lengyel M. & Fiser J. (2013) The role of time in human decision-making. VSS 2013, Journal of Vision 13 (9), 305-305 [Abstract]
The effects of time on human decision-making are well known, yet, the precise mechanisms underlying these effects remain unclear. Under the classic signal processing framework (e.g. integration-to-bound) the passing of time allows for accumulation of evidence, parametric models of probabilistic neural representations (e.g. PPC) hold that time is used for averaging internal noise for a […]
Lengyel G., Lengyel M., & Fiser J. (2022) Contextual learning and inference in perceptual learning Journal of Vision 22 (14), 3999-3999 [Abstract]
Recent studies established that perceptual learning (PL) is influenced by strong top-down effects and shows flexible generalization depending on context. However, current computational models of PL utilize feedforward architectures and fail to capture parsimoniously these context-dependent and generalization effects in more complex PL tasks. We propose a Bayesian framework that combines sensory bottom-up and experience-based […]
Bex P., Christensen JH. & Fiser J. (2018) Optimal variance encoding of contours in naturalistic images. ECVP 2018 [Abstract]
We investigated feature ensemble encoding at the lowest level of visual processing by focusing on contour encoding in natural images. In such images, the mean contour is not a single value, but it varies locally with spatial position, and variability of the contour can be quantified by the noisiness of the contour segments. We used […]
Jellinek S. & Fiser J. (2016) Evidence for automatic generative learning in humans. ECVP 2016, Perception 45, 274-274 [Abstract]
It is commonly assumed that humans learn generative or discriminative representations of the sensory input depending on task context (e.g. Hsu & Griffiths, 2010). Following our earlier findings (Orban et al., 2008), we propose that humans always form generative models based on the statistics of the input. To test this proposal, we investigated whether a […]
Jellinek S. & Fiser J. (2014) Neural correlates of learning and uncertainty during the acquisition of novel categories. BCCCD 2014, Budapest, Hungary [Abstract]
In our study, we addressed the question of whether and how the learning process of a novel category and uncertainty in our knowledge about it is reflected in ERP responses and alpha-band suppression of the brain. To test these ideas, we built our experimental procedure on the oddball paradigm that is frequently used to investigate […]
Savin C., Berkes P., Chiu C., Fiser J. & Lengyel M. (2013) Similarity between spontaneous and sensory-evoked activity does suggest learning in the cortex. COSYNE 2013, Salt Lake City, UT [Abstract]
The developmental increase in similarity between spontaneous (SA) and average stimulus-evoked activity (EA) in the primary visual cortex has been suggested to reflect a progressive adaptation of the animal’s internal model to the statistics of the environment (Berkes et al., Science 2011). However, it is unknown how much of this adaptation is due to learning […]