Fiser J., Popovic M., Haefner RM. & Lengyel M. (2013) Time and making perceptual decisions. ECVP 2013, Perception 42, 237-237 [Abstract]
In models of perceptual decision making within the classical signal processing framework (e.g. integration-to-bound), time is used to accumulate evidence. In probabilistic, sampling-based frameworks, time is necessary to collect samples from subjective posterior distributions for the decision. Which role is dominant during perceptual decisions? We have analytically derived the progression of the error and subjective […]
Fiser J. (2013) B10: Bayesian methods and generative models. ECVP 2013, Perception 42, 4-5 [Abstract]
In the last two decades, a quiet revolution took place in vision research, in which Bayesian methods replaced the once-dominant signal detection framework as the most suitable approach to modeling visual perception and learning. This tutorial will review the most important aspects of this new framework from the point of view of vision scientists. We […]
Popovic M., Van Hooser S. & Fiser J. (2013) Testing the functional significance of directional selectivity in the developing primary visual cortex SFN 2013, San Diego, CA [Abstract]
Directional selectivity (DS) is known to increase significantly in ferrets during two weeks after eye opening and it has been shown to strongly depend on visual experience (Li et al. 2008, Nature). Such selectivity to features of the input is traditionally assumed to indicate the functional maturity of the visual system, however, this assumption has […]
Haefner RM., Berkes P. & Fiser J. (2013) Top-down influences on sensory processing during perceptual decision-making and attention. SFN 2013, San Diego, CA [Abstract]
Recent work has established the importance of top-down influences on early sensory processing. These influences are alternatively taken as representing task context, attention, expectation, working memory and motor commands (Gilbert & Li, 2013). At the same time, top-down influences have been recognized as essential for supporting probabilistic inference (Lee & Mumford, 2003). Here, we combine […]
Osik JJ., Roy A., Ritter NJ., Miller J., Wang Y., Fiser J. & Van Hooser SD. (2014) Spatiotemporally controlled optogenetic activation of developing ferret visual cortex. SFN 2014, Washington, DC [Abstract]
Realizing the full potential of optogenetic techniques will require concurrent development of light delivery technologies that improve spatial and temporal control of neuronal stimulation to facilitate increasingly informative electrophysiology recordings. Excitation (or inhibition) by light-activation of channelrhodopsin (ChR) and its many variants has quickly emerged as a preferred methodology in the neurosciences by reason of […]
Jellinek S. & Fiser J. (2014) Dissociation of alpha ERD and P300 measures of categorization with continuously varying stimuli. SFN 2014, Washington, DC [Abstract]
EEG measures, especially alpha ERD and P3 ERP, has often been used as a tool for the investigation of the structure of categorical and conceptual representation of incoming stimuli. Studies of categorization that use alpha ERD and P3 signals typically have three characteristics: they use the oddball paradigm, the categories consist of discretely separable exemplars, […]
Arató J. & Fiser J. (2014) Short term and baseline effect in the estimation of probabilistic visual event sequences. ECVP 2014, Perception 43, 54-54 [Abstract]
Humans’ reliance on expectations based on past experience to evaluate uncertain sensory events of their environment has been interpreted either as local adaptation or probabilistic implicit inference. However the exact interplay between immediate past and longer-term sensory experiences in influencing these expectations has not yet been experimentally explored. In a simple probabilistic visual 2-AFC task, […]
Jellinek S. & Fiser J. (2014) Alpha ERD reflects learning and uncertainty during the acquisition of novel categories. ECVP 2014, Perception 43, 54-54 [Abstract]
How are the learning process of a novel category and uncertainty about the category reflected in the alpha-band suppression of the brain? We built an experimental procedure on the oddball paradigm frequently used to investigate the nature of category representations in humans, but contrary to similar studies, we used a continuous stimulus dimension and recorded […]
Christensen JH., Lengyel M. & Fiser J. (2014) Factors determining the balance between evidence integration and probabilistic sampling in perceptual decision-making. ECVP 2014, Perception 43, 24-24 [Abstract]
We have reported that contrary to theories of Evidence Integration (EI), time in visual perceptual decision-making is needed not only for accumulating external sensory evidence, but also for collecting samples from static internally represented distributions as it is predicted by the theory of Probabilistic Sampling (PS) (Cosyne 2013; VSS 2013). However, the precise relationship between […]
Arató J. & Fiser J. (2014) Short term and baseline effect in the estimation of probabilistic visual event sequences. VSS 2014,Journal of Vision 14 (10), 373-373 [Abstract]
To understand how people build probabilistic internal representations of their dynamic perceptual environment, it is essential to know how the statistical structures of event sequences are encoded in the brain. Previous attempts either characterized this coding by the structure of short-term repetition/alternations or while acknowledging the importance of long-term baseline probabilities, they failed to explore […]