Search results for "Visual Perception"
showing 10 items of 387 documents
Perceptual semantics: A three-level approach
2010
In this work we suggest a model according to which semantics has been already generated during the perception through the interaction of three dynamic levels of perceptual organization. We consider perceptual grouping as the first order processing. Shape formation is considered as the second order processing. Both grouping and shape formation can be considered as two complementary and interrelated processes of perceptual organization. The third — partially overlapping — level is meaning assignment. Most of the results are supported by empirical evidence based on new visual illusions of shape and meaning and are consistent with several other proposals (e.g., [1], [2] and [3]).
Influence of Global Structure on Musical Target Detection and Recognition
1998
The present study adapted a paradigm used in visual perception by Biederman, Glass, and Stacy (1973) and analyzed the influence of a coherent global context on the detection and recognition of musical target excerpts. Global coherence was modified by segmenting minuets into chunks of four, two, or one bar. These chunks were either reordered (Experiments 1, 3, 4, 5) or transposed to different keys (Experiment 2). The results indicate that target detection is influenced only by a reorganization on a very local level (i.e. chunks of one bar). Context incoherence did not influence the recognition of the real targets, but rendered the rejection of wrong target excerpts (foils) more difficult. Th…
Transposed-Letter Priming Effects for Close Versus Distant Transpositions
2009
Transposing two internal letters of a word produces a perceptually similar item (e.g., CHOLOCATE being processed as CHOCOLATE). To determine the precise nature of the encoding of letter position within a word, we examined the effect of the number of intervening letters in transposed-letter effects with a masked priming procedure. In Experiment 1, letter transposition could involve adjacent letters (chocloate-CHOCOLATE) and nonadjacent letters with two intervening letters (choaolcte-CHOCOLATE). Results showed that the magnitude of the transposed-letter priming effect – relative to the appropriate control condition – was greater when the transposition involved adjacent letters than when it i…
Do happy faces really modulate liking for Jackson Pollock art and statistical fractal noise images?
2017
Flexas et al. (2013) demonstrated that happy faces increase preference for abstract art if seen in short succession. We could not replicate their findings. In our first experiment, we tested whether valence, saliency or arousal of facial primes can modulate liking of Jackson Pollock art crops. In the second experiment, the emphasis was on testing another type of abstract visual stimuli which possess similar low-level image features: statistical fractal noise images. Pollock crops were rated significantly higher when primed with happy faces in contrast to neutral faces, but not differently to the no-prime condition. Findings of our study suggest that affective priming with happy faces may be…
Encoding into Visual Working Memory: Event-Related Brain Potentials Reflect Automatic Processing of Seemingly Redundant Information.
2013
Encoding and maintenance of information in visual working memory in an S1-S2 task with a 1500 ms retention phase were investigated by means of event-related brain potentials (ERPs). Participants were asked to decide whether two visual stimuli were physically identical (identity comparison (IC) task) or belonged to the same set or category of equivalent patterns (category comparison (CC) task). The stimuli differ with regard to two features. (1) Each pattern can belong to a set of either four (ESS 4) or eight (ESS 8) equivalent patterns, mirroring differences in the complexity with regard to the representational structure of each pattern (i.e., equivalence set size (ESS)). (2) The set of pat…
The Adequate Stimulus
2008
The term adequate stimulus describes that class of environmental phenomena that requires the least amount of energy to elicit a percept mediated by a particular sensory system, implying that the receptive organs of that sensory system are specialized to detect those phenomena. It was difficult to transfer this concept to the perception of pain and to the nociceptive system. Many different stimuli may cause pain (pin prick, burn injury, freeze injury, inflammation, etc.), none of which needs particularly low amounts of energy. The common denominator of those stimuli is that they threaten to cause tissue damage (in Greek: νoξη Noxe). Hence the adequate stimulus to elicit pain is traditionally…
Modelling the Effects of Internal Textures on Symmetry Detection Using Fuzzy Operators
2009
Symmetry is a crucial dimension which aids the visual system, human as well as artificial, to organize its environment and to recognize forms and objects. In humans, detection of symmetry, especially bilateral and rotational, is considered to be a primary factor for discovering and interacting with the surrounding environment. Rotational symmetry detecting can be affected by less-known factors, such as the stimulus internal texture. This paper explores how fuzzy operators can be usefully employed in modeling the effects of the internal texture on symmetry detection. To this aim, we selected two symmetry detection algorithms, based on different computational models, and compared their output…
Perceptual adaptive insensitivity for support vector machine image coding.
2005
Support vector machine (SVM) learning has been recently proposed for image compression in the frequency domain using a constant epsilon-insensitivity zone by Robinson and Kecman. However, according to the statistical properties of natural images and the properties of human perception, a constant insensitivity makes sense in the spatial domain but it is certainly not a good option in a frequency domain. In fact, in their approach, they made a fixed low-pass assumption as the number of discrete cosine transform (DCT) coefficients to be used in the training was limited. This paper extends the work of Robinson and Kecman by proposing the use of adaptive insensitivity SVMs [2] for image coding u…
Spatial-temporal interactions in the human brain
2009
The review summarises current evidence on the cognitive mechanisms for the integration of spatial and temporal representations and of common brain structures to process the where and when of stimuli. Psychophysical experiments document the presence of spatially localised distortions of sub-second time intervals and suggest that visual events are timed by neural mechanisms that are spatially selective. On the other hand, experiments with supra-second intervals suggest that time could be represented on a mental time-line ordered from left-to-right, similar to what is reported for other ordered quantities, such as numbers. Neuroimaging and neuropsychological findings point towards the posterio…
Comparative assessment of spatial perception in augmented reality depending on the consistency of depth cues
2021
Discrepancies between depth cues (accommodation and vergence) is one of the major issues caused in a stereoscopic augmented reality at close viewing distances. It adversely affects not only user comfort but also spatial judgements. Images with consonant cues at different distances have become available due to the implementation of multifocal architecture in the head-mounted displays, although its effect on spatial perception has remained unknown. In this psychophysical study, we investigated the effects of consonant and conflicting depth cues on perceptual distance matching in the stereoscopic environment of augmented reality using a head-mounted display that was driven in two modes: multif…