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Natural Scene Perception
Natural scene perception refers to the process by which an agent (such as a human being) visually takes in and interprets scenes that it typically encounters in natural modes of operation (e.g. busy streets, meadows, living rooms). This process has been modeled in several different ways that are guided by different concepts. Debate over role of attention One major dividing line between theories that explain natural scene perception is the role of attention. Some theories maintain the need for focused attention, while others claim that focused attention is not involved. Focused attention played a partial role in early models of natural scene perception. Such models involved two stages of visual processing. According to these models, the first stage is attention free and registers low level features such as brightness gradients, motion and orientation in a parallel manner. Meanwhile, the second stage requires focused attention. It registers high-level object descriptions, has li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scene (perception)
In the field of perception, a scene is information that can flow from a physical environment into a perceptual system via sensory transduction. A perceptual system is designed to interpret scenes. Examples of scenes include * Still images * Binocular still images * Moving images ( movies) * Binocular moving images (~3D movies) * Sounds of a local environment (audio recordings) * Tactile properties of a local environment. A natural scene is a scene that a perceptual system would typically encounter in a natural mode of operation. Therefore, a very relevant area of research is natural scene statistics Scene statistics is a discipline within the field of perception. It is concerned with the statistical regularities related to scenes. It is based on the premise that a perceptual system is designed to interpret scenes. Biological perceptual sy .... References Perception {{psych-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Processing (psychology)
In psychology, parallel processing is the ability of the brain to simultaneously process incoming stimuli of differing quality. Parallel processing is associated with the visual system in that the brain divides what it sees into four components: color, motion, shape, and depth. These are individually analyzed and then compared to stored memories, which helps the brain identify what you are viewing. The brain then combines all of these into the field of view that then seen and comprehended. Parallel processing has been linked, by some experimental psychologists, to the stroop effect. This is a continual and seamless operation. For example, if one is standing between two different groups of people who are simultaneously carrying on two different conversations, one may be able to pick up only some information of both conversation at the same time. Background Parallel Distributed Processing Models are neurally inspired, emulating the organisational structure of nervous syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipital Lobe
The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin ''ob'', "behind", and ''caput'', "head". The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1 (visual one). Human V1 is located on the medial side of the occipital lobe within the calcarine sulcus; the full extent of V1 often continues onto the occipital pole. V1 is often also called striate cortex because it can be identified by a large stripe of myelin, the Stria of Gennari. Visually driven regions outside V1 are called extrastriate cortex. There are many extrastriate regions, and these are specialized for different visual tasks, such as visuospatial processing, color differentiation, and motion perception. Bilateral lesions of the occipital lobe can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Short-term Memory
In the study of vision, visual short-term memory (VSTM) is one of three broad memory systems including iconic memory and long-term memory. VSTM is a type of short-term memory, but one limited to information within the visual domain. The term VSTM refers in a theory-neutral manner to the non-permanent storage of visual information over an extended period of time. The visuospatial sketchpad is a VSTM subcomponent within the theoretical model of working memory proposed by Alan Baddeley; in which it is argued that a working memory aids in mental tasks like planning and comparison. Whereas iconic memories are fragile, decay rapidly, and are unable to be actively maintained, visual short-term memories are robust to subsequent stimuli and last over many seconds. VSTM is distinguished from long-term memory, on the other hand, primarily by its very limited capacity. Overview The introduction of stimuli which were hard to verbalize, and unlikely to be held in long-term memory, revolutionized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parahippocampal Place Area
The parahippocampal gyrus (or hippocampal gyrus') is a grey matter cortical region of the brain that surrounds the hippocampus and is part of the limbic system. The region plays an important role in memory encoding and retrieval. It has been involved in some cases of hippocampal sclerosis. Asymmetry has been observed in schizophrenia. Structure The anterior part of the gyrus includes the perirhinal and entorhinal cortices. The term parahippocampal cortex is used to refer to an area that encompasses both the posterior parahippocampal gyrus and the medial portion of the fusiform gyrus. Function Scene recognition The parahippocampal place area (PPA) is a sub-region of the parahippocampal cortex that lies medially in the inferior temporo-occipital cortex. PPA plays an important role in the encoding and recognition of environmental scenes (rather than faces). fMRI studies indicate that this region of the brain becomes highly active when human subjects view topographical scene s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraparietal Sulcus
The intraparietal sulcus (IPS) is located on the lateral surface of the parietal lobe, and consists of an oblique and a horizontal portion. The IPS contains a series of functionally distinct subregions that have been intensively investigated using both single cell neurophysiology in primates and human functional neuroimaging. Its principal functions are related to perceptual-motor coordination (e.g., directing eye movements and reaching) and visual attention, which allows for visually-guided pointing, grasping, and object manipulation that can produce a desired effect. The IPS is also thought to play a role in other functions, including processing symbolic numerical information, visuospatial working memory and interpreting the intent of others. Function Five regions of the intraparietal sulcus (IPS): anterior, lateral, ventral, caudal, and medial * LIP & VIP: involved in visual attention and saccadic eye movements * VIP & MIP: visual control of reaching and pointing * AIP: visu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Event-related Potential
An event-related potential (ERP) is the measured brain response that is the direct result of a specific sensory, cognitive, or motor event. More formally, it is any stereotyped electrophysiological response to a stimulus. The study of the brain in this way provides a noninvasive means of evaluating brain functioning. ERPs are measured by means of electroencephalography (EEG). The magnetoencephalography (MEG) equivalent of ERP is the ERF, or event-related field. Evoked potentials and induced potentials are subtypes of ERPs. History With the discovery of the electroencephalogram (EEG) in 1924, Hans Berger revealed that one could measure the electrical activity of the human brain by placing electrodes on the scalp and amplifying the signal. Changes in voltage can then be plotted over a period of time. He observed that the voltages could be influenced by external events that stimulated the senses. The EEG proved to be a useful source in recording brain activity over the en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FMRI
Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. The primary form of fMRI uses the blood-oxygen-level dependent (BOLD) contrast, discovered by Seiji Ogawa in 1990. This is a type of specialized brain and body scan used to map neural activity in the brain or spinal cord of humans or other animals by imaging the change in blood flow ( hemodynamic response) related to energy use by brain cells. Since the early 1990s, fMRI has come to dominate brain mapping research because it does not involve the use of injections, surgery, the ingestion of substances, or exposure to ionizing radiation. This measure is frequently corrupted by noise from various sources; hence, statistical procedures are used to extract the underlying signal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurons
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell body ( soma), dendrites, and a single axon. The soma is a compact structure, and the axon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feedforward Neural Network
A feedforward neural network (FNN) is an artificial neural network wherein connections between the nodes do ''not'' form a cycle. As such, it is different from its descendant: recurrent neural networks. The feedforward neural network was the first and simplest type of artificial neural network devised. In this network, the information moves in only one direction—forward—from the input nodes, through the hidden nodes (if any) and to the output nodes. There are no cycles or loops in the network. Single-layer perceptron The simplest kind of neural network is a ''single-layer perceptron'' network, which consists of a single layer of output nodes; the inputs are fed directly to the outputs via a series of weights. The sum of the products of the weights and the inputs is calculated in each node, and if the value is above some threshold (typically 0) the neuron fires and takes the activated value (typically 1); otherwise it takes the deactivated value (typically -1). N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Hierarchy
Visual hierarchy, according to Gestalt psychology, is a pattern in the visual field wherein some elements tend to "stand out," or attract attention, more strongly than other elements, suggesting a hierarchy of importance. While it may occur naturally in any visual field, the term is most commonly used in design (especially graphic design and cartography), where elements are intentionally designed to make some look more important than others. This order is created by the visual contrast between forms in a field of perception. Objects with highest contrast to their surroundings are recognized first by the human mind. Evidence There is some scientific evidence for visual hierarchy using eye tracking. For example, one study found that when people agree that a graphic design is good, they exhibit more similar eye movements; measured by the Fréchet distance. Theory The concept of visual hierarchy is based in Gestalt psychological theory, an early 20th-century German theory that pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual-task Paradigm
A dual-task paradigm is a procedure in experimental neuropsychology that requires an individual to perform two tasks simultaneously, in order to compare performance with single-task conditions. When performance scores on one and/or both tasks are lower when they are done simultaneously compared to separately, these two tasks interfere with each other, and it is assumed that both tasks compete for the same class of information processing Information processing is the change (processing) of information in any manner detectable by an observer. As such, it is a process that ''describes'' everything that happens (changes) in the universe, from the falling of a rock (a change in posit ... resources in the brain. For instance, reciting poetry while riding a bike are two tasks that can be performed just as well separately as simultaneously. However, reciting poetry while writing an essay should deteriorate performance on at least one of these two tasks, because they interfere with each ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
