PerceptionPerception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system. Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves.
Visual memoryVisual memory describes the relationship between perceptual processing and the encoding, storage and retrieval of the resulting neural representations. Visual memory occurs over a broad time range spanning from eye movements to years in order to visually navigate to a previously visited location. Visual memory is a form of memory which preserves some characteristics of our senses pertaining to visual experience. We are able to place in memory visual information which resembles objects, places, animals or people in a mental image.
N400 (neuroscience)The N400 is a component of time-locked EEG signals known as event-related potentials (ERP). It is a negative-going deflection that peaks around 400 milliseconds post-stimulus onset, although it can extend from 250-500 ms, and is typically maximal over centro-parietal electrode sites. The N400 is part of the normal brain response to words and other meaningful (or potentially meaningful) stimuli, including visual and auditory words, sign language signs, pictures, faces, environmental sounds, and smells.
Neural correlates of consciousnessThe neural correlates of consciousness (NCC) refer to the relationships between mental states and neural states and constitute the minimal set of neuronal events and mechanisms sufficient for a specific conscious percept. Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena; that is, neural changes which necessarily and regularly correlate with a specific experience.
P600 (neuroscience)The P600 is an event-related potential (ERP) component, or peak in electrical brain activity measured by electroencephalography (EEG). It is a language-relevant ERP component and is thought to be elicited by hearing or reading grammatical errors and other syntactic anomalies. Therefore, it is a common topic of study in neurolinguistic experiments investigating sentence processing in the human brain.
N200 (neuroscience)The N200, or N2, is an event-related potential (ERP) component. An ERP can be monitored using a non-invasive electroencephalography (EEG) cap that is fitted over the scalp on human subjects. An EEG cap allows researchers and clinicians to monitor the minute electrical activity that reaches the surface of the scalp from post-synaptic potentials in neurons, which fluctuate in relation to cognitive processing. EEG provides millisecond-level temporal resolution and is therefore known as one of the most direct measures of covert mental operations in the brain.
Difference due to memoryDifference due to memory (Dm) indexes differences in neural activity during the study phase of an experiment for items that subsequently are remembered compared to items that are later forgotten. It is mainly discussed as an event-related potential (ERP) effect that appears in studies employing a subsequent memory paradigm, in which ERPs are recorded when a participant is studying a list of materials and trials are sorted as a function of whether they go on to be remembered or not in the test phase.
Visual cortexThe visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 (V1), Brodmann area 17, or the striate cortex.
Visual systemThe visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (the ability to detect and process visible light) as well as enabling the formation of several non-image photo response functions. It detects and interprets information from the optical spectrum perceptible to that species to "build a representation" of the surrounding environment.
N170The N170 is a component of the event-related potential (ERP) that reflects the neural processing of faces, familiar objects or words. Furthermore, the N170 is modulated by prediction error processes. When potentials evoked by images of faces are compared to those elicited by other visual stimuli, the former show increased negativity 130-200 ms after stimulus presentation. This response is maximal over occipito-temporal electrode sites, which is consistent with a source located at the fusiform and inferior-temporal gyri, confirmed by electrocorticography.
