Fiser J. & Biederman I. (2001) Invariance of long-term visual priming to scale, reflection, translation, and hemisphere. Vision Research 41 (2), 221-234
The representation of shape mediating visual object priming was investigated. In two blocks of trials, subjects named images of common objects presented for 185 ms that were bandpass filtered, either at high (10 cpd) or at low (2 cpd) center frequency with a 1.5 octave bandwidth, and positioned either 5º right or left of fixation. […]
Fiser J., Subramaniam S. & Biederman I. (2001) Size tuning in the absence of spatial frequency tuning in object recognition. Vision Research 41 (15), 1931-1950
How do we attend to objects at a variety of sizes as we view our visual world? Because of an advantage in identification of lowpass over highpass filtered patterns, as well as large over small images, a number of theorists have assumed that size-independent recognition is achieved by spatial frequency (SF) based coarse-to-fine tuning. We […]
Fiser J. & Aslin RN. (2001) Unsupervised statistical learning of higher-order spatial structures from visual scenes. Psychological science 12 (6), 499-504
Three experiments investigated the ability of human observers to extract the joint and conditional probabilities of shape co-occurrences during passive viewing of complex visual scenes. Results indicated that statistical learning of shape conjunctions was both rapid and automatic, as subjects were not instructed to attend to any particular features of the displays. Moreover, in addition […]
Fiser J. & Aslin RN. (2002) Statistical learning of higher-order temporal structure from visual shape sequences.. Journal of Experimental Psychology: Learning, Memory, and Cognition 28 (3), 458
In 3 experiments, the authors investigated the ability of observers to extract the probabilities of successive shape co-occurrences during passive viewing. Participants became sensitive to several temporal-order statistics, both rapidly and with no overt task or explicit instructions. Sequences of shapes presented during familiarization were distinguished from novel sequences of familiar shapes, as well as […]
Fiser J. & Aslin RN. (2002) Statistical learning of new visual feature combinations by infants. Proceedings of the National Academy of Sciences 99 (24), 15822-15826
The ability of humans to recognize a nearly unlimited number of unique visual objects must be based on a robust and efficient learning mechanism that extracts complex visual features from the environment. To determine whether statistically optimal representations of scenes are formed during early development, we used a habituation paradigm with 9-month-old infants and found […]
Weliky M., Fiser J., Hunt RH. & Wagner DN. (2003) Coding of natural scenes in primary visual cortex. Neuron 37 (4), 703-718
Natural scene coding in ferret visual cortex was investigated using a new technique for multi-site recording of neuronal activity from the cortical surface. Surface recordings accurately reflected radially aligned layer 2/3 activity. At individual sites, evoked activity to natural scenes was weakly correlated with the local image contrast structure falling within the cells’ classical receptive […]
Fiser J., Bex PJ. & Makous W. (2003) Contrast conservation in human vision. Vision Research 43 (25), 2637-2648
Visual experience, which is defined by brief saccadic sampling of complex scenes at high contrast, has typically been studied with static gratings at threshold contrast. To investigate how suprathreshold visual processing is related to threshold vision, we tested the temporal integration of contrast in the presence of large, sudden changes in the stimuli such occur […]
Fiser J., Chiu C. & Weliky M. (2004) Small modulations of ongoing cortical dynamics by sensory input during natural vision, Nature 2004 Sep 30; 431:573-578.
During vision, it is believed that neural activity in the primary visual cortex is predominantly driven by sensory input from the environment. However, visual cortical neurons respond to repeated presentations of the same stimulus with a high degree of variability. Although this variability has been considered to be noise owing to random spontaneous activity within […]
Fiser J. & Aslin RN. (2005) Encoding multielement scenes: statistical learning of visual feature hierarchies. Journal of Experimental Psychology: General 134 (4), 521
The authors investigated how human adults encode and remember parts of multielement scenes composed of recursively embedded visual shape combinations. The authors found that shape combinations that are parts of larger configurations are less well remembered than shape combinations of the same kind that are not embedded. Combined with basic echanisms of statistical learning, this […]
Aslin RN. & Fiser J. (2005) Methodological challenges for understanding cognitive development in infants. Trends in cognitive sciences 9 (3), 92-98
Studies of cognitive development in human infants have relied almost entirely on descriptive data at the behavioral level – the age at which a particular ability emerges. The underlying mechanisms of cognitive development remain largely unknown, despite attempts to correlate behavioral states with brain states. We argue that research on cognitive development must focus on […]