Cognitive quiz 6 Flashcards
Apperceptive agnosia
Visual perceptual disorder that impairs (ухудшает) the ability to recognize objects, forms, or shapes due to difficulties in perceiving and analyzing visual information accurately.
Difficulties with:
1. recognizing shapes, faces, or objects
2. combining different visual features: lines, colors, or textures, into a whole (в единое целое)
3. tasks that involve copying or matching (сопоставление) visual stimuli, such as drawings (рисунки) or puzzles
4. reproducing shapes or patterns accurately (воспроизведением форм или узоров)
5. misperceiving (неправильное восприятие) the size, orientation, or spatial relationships of objects (пространственных соотношений объектов).
Unlike other visual impairments (нарушений), individuals with apperceptive agnosia typically have intact visual acuity (сохраненную остроту зрения), meaning their eyesight (зрение) is normal.
Apperceptive agnosia happens due to damage or dysfunction in the pathways leading from the primary visual cortex to the secondary and associative visual areas (путей, ведущих от первичной зрительной коры ко вторичной и ассоциативной зрительным областям).
In apperceptive agnosia, the primary visual cortex (V1) is intact (не повреждена). The disruption occurs primarily in the connection between V1 and higher visual areas, such as V2 and V3, which are responsible for more complex visual processing.
In apperceptive agnosia, the disruption in the visual pathways that connect V1, V2, V3 areas leads to a breakdown (разрушение) in the ability to interpret and make sense of visual stimuli (способности интерпретировать и придавать смысл зрительным стимулам). While the early visual cortices (V1, V2, V3) might be structurally intact, the connectivity (связь) and communication with higher visual areas may be compromised (нарушена), leading to the symptoms of apperceptive agnosia.
Апперцептивная агнозия связана с трудностями в формировании цельного визуального восприятия объекта. Это значит, что человек может видеть отдельные элементы объекта, предметов, но не может их собрать вместе, чтобы распознать весь объект. При этом базовые визуальные функции человека (контраст и цвет) остаются неповрежденными.
Early Visual Cortex (V1, V2, V3)
The primary visual cortex (V1), located in the occipital lobe (затылочной доле) at the back of the brain, is responsible for initial (первоначальную) processing of visual information. V1 is the first stop for visual information in the brain. It receives signals from the eyes and processes basic visual features (характеристики) such as edges (края), lines, and orientation. V1 helps in constructing an initial representation of the visual world (построении первоначального представления визуального мира).
Visual Area 2 (V2):
V2 is the next area after V1 in the visual processing hierarchy.
It receives information from V1 and further analyzes and integrates visual features. V2 helps in perceiving more complex visual attributes like shapes, colors, and textures.
Visual Area 3 (V3):
V3 is the third area in the early visual cortex. It receives inputs from V2 and continues to process and refine (усовершенствовать) visual information. V3 is involved in higher-level visual processing, including the perception of depth (глубины) and motion (движения).
Function and Interconnections (взаимосвязи): V1, V2, and V3 work together in a hierarchical manner (образом) to process visual information. Information flows (поступает) from V1 to V2, and then from V2 to V3, with each area building upon the representations created by the previous area (каждая область основывается на изображениях, созданных предыдущей областью).
This sequential processing (последовательная обработка) helps in extracting (извлекать) more complex visual features and forming a coherent (целостное) perception of the visual world.
In summary, the early visual cortex, comprising (включающая) V1, V2, and V3, is responsible for the initial processing of visual information. V1 processes basic visual features, while V2 and V3 analyze more complex attributes (свойства). These areas work together in a hierarchical manner to build representations of the visual world, allowing us to perceive shapes, colors, textures, depth, and motion.
V1 - receives signals from the eyes. edges (края), lines, and orientation.
V2 - information from V1. shapes, colors, and textures.
V3 - receives inputs from V2. perception of depth (глубины) and motion (движения).
Associative agnosia (Ассоциативная агнозия)
Visual perceptual disorder in which is difficult to recognize and interpret visual stimuli, even though their early visual processing is intact (ранняя зрительная обработка не нарушена).
It is characterized by a failure (неспособностью) to assign meaning or make sense (неспособностью придать значение или осмыслить) of what is being seen.
Symptoms:
1. Object recognition deficits: Individuals with associative agnosia struggle to recognize familiar objects or visually presented stimuli, such as common objects, faces, or places.
2. Difficulty with visual categorization (классификацией): trouble with categorizing objects based on their visual features or grouping them into meaningful categories (значимым категорям).
3. Impaired visual memory (Нарушение зрительной памяти): Associative agnosia can also affect visual memory, difficulties with recalling and recognizing previously seen objects or faces.
4. Preservation (Сохранение) of basic visual abilities: Unlike other visual impairments (нарушений), individuals have intact visual acuity (сохраненной остротой зрения) and basic visual processing abilities.
5. Normal intellectual functioning (Нормальное интеллектуальное функционирование): The impairment is specific to visual recognition (рительного распознавания) and does not impact general intellectual functioning.
Involvement of the Lateral Occipital Complex (LOC) - Поражение латерального затылочного комплекса:
The Lateral Occipital Complex (LOC) is a brain region located in the occipital and temporal lobes (затылочной и височной долях), involved in higher-level visual processing and object recognition.
In associative agnosia, the dysfunction primarily occurs in the LOC, disrupting the ability to integrate visual information and associate it with semantic knowledge.
The LOC plays a crucial role in connecting visual perception with stored knowledge and memories related to objects and their meaning.
Dysfunction in the LOC leads to difficulties in accessing and retrieving this semantic information, resulting in impaired recognition and interpretation of visual stimuli.
In summary, associative agnosia is a visual perceptual disorder characterized by difficulties in recognizing and assigning meaning to visual stimuli. Individuals with this condition have intact early visual processing but struggle with object recognition, visual categorization, and visual memory. The impairment arises from dysfunction in the Lateral Occipital Complex (LOC), which disrupts the integration of visual information with semantic knowledge, resulting in an inability to make sense of what is being seen.
Ассоциативная агнозия относится к трудностям связать визуальное восприятие объекта с предыдущими знаниями об этом объекте. Человек может описать объект и его внешний вид, но не может распознать или назвать его.
Ассоциативная агнозия — невозможность семантически категоризировать предмет (объяснить, зачем он нужен, что с ним делают, как он называется), форма которого при этом воспринимается правильно (может точно перерисовать).
Prosopagnosia
Пациенты испытывают трудности в распознавании лиц. Они могут воспринимать лица как набор отдельных особенностей, но не могут их синтезировать в уникальное “целое”. У них может быть способность распознавать объекты.
N170
The N170 is an event-related potential (ERP) component (компонент потенциала, связанного с событием) recorded from the scalp using electroencephalography (EEG).
It is a neural response that occurs approximately 170 milliseconds after viewing (рассмотрение) a face stimulus, hence (отсюда) the name N170.
The N170 is particularly sensitive to face processing and is often used as an electrophysiological marker of face perception.
N170 - это компонент электроэнцефалограммы (EEG), который представляет собой отрицательное возбуждение, происходящее примерно в 170 миллисекунд после предъявления визуального стимула. N170 выражен в ответ на стимулы лиц.
Involvement of the Fusiform Gyrus (Веретенообразная извилина)
The fusiform gyrus is a brain region located in the temporal lobe (височной доле), specifically in the ventral visual pathway (вентральном зрительном тракте).
It is commonly associated with face processing and recognition (обработкой и распознаванием лиц).
In individuals with prosopagnosia, there is often dysfunction or reduced activation in the fusiform gyrus during face perception tasks.
The fusiform gyrus is believed to play a critical role in processing facial features and integrating them into a holistic (целостное) representation of a face (обработке черт лица и их интеграции в целостное представление о лице).
The N170, an ERP component, is a neural marker of face processing (нейронным маркером обработки лиц). Dysfunction in the fusiform gyrus, a region associated with face processing (обработкой лица), often have individuals with prosopagnosia. This disrupts the integration of facial features (черт лица) and impairs the ability to recognize and process faces.
Parahippocampal place area (Область парагиппокампального пространства)
In the posterior parahippocampal gyrus, there are many neurons that respond most strongly to “spaces” (scenes, rooms, buildings in locations), as opposed to objects and face. Seeing “where”.
Inferior temporal lobe lesions (Поражения нижней височной доли): impairs learning of discrimination of rewarded objects by shape, color, texture (ухудшает способность различать вознаграждаемые объекты по форме, цвету, текстуре).
Posterior parietal lesions (Поражения задней части теменной области): impair learning selection of rewarded positions by proximity to landmark (затрудняют обучение выбору вознаграждаемых позиций в зависимости от близости к ориентиру).
Therefore, 2 separate perceptual abilities.
Dorsal and Ventral Streams (дорсальный и вентральный потоки)
Два основных пути обработки визуальной информации в мозге.
Вентральный поток (называемый “что” или потоком распознавания объектов) проходит из первичной визуальной коры в затылочный и височный доли мозга. Отвечает за распознавание объектов - их формы, цвета и др.
Дорсальный поток (называемый “где” или потоком пространственной локализации) проходит из первичной визуальной коры в теменную долю. Отвечает за пространственное восприятие: где объекты находятся в пространстве относительно нас и друг друга, и как мы можем взаимодействовать с ними.
The dorsal and ventral streams are two distinct pathways in the brain involved in visual processing.
They are often referred to as the “where” and “what” pathways.
- The dorsal stream is responsible for processing the spatial location and movement (пространственного расположения и перемещения) of visual stimuli.(where)
It starts from the primary visual cortex (V1) and extends to the parietal lobe (первичной зрительной коры (V1) и распространяется на теменную долю). The dorsal stream helps us answer questions like “Where is an object located?” and “How is it moving?” It plays a crucial role in visual attention (зрительном внимании), visually guided actions (визуально управляемых действиях), and spatial awareness (пространственном восприятии). - The ventral stream is responsible for processing the visual characteristics and identity of objects (what). It begins from the primary visual cortex (V1) and extends to the temporal lobe (аспространяется на височную долю). The ventral stream helps us answer questions like “What is the object?” and “What are its features?”
It is involved in object recognition, perception of colors, shapes, and faces, and extracting meaning (извлечении смысла) from visual stimuli.
Functional Differences between the dorsal stream and the ventral stream
The dorsal stream prioritizes the spatial and temporal aspects of vision (отдает приоритет пространственным и временным аспектам зрения), allowing us to interact with the environment and navigate our surroundings (взаимодействовать с окружающей средой и ориентироваться в ней).
The ventral stream prioritizes the detailed analysis of visual information, enabling us to recognize and interpret objects and their attributes (позволяя нам распознавать и интерпретировать объекты и их атрибуты).
Interaction between the dorsal stream and the ventral stream
they interact to provide a holistic understanding of visual perception.
The information processed (обрабатываемая) in the ventral stream can influence attention and guide the processing in the dorsal stream.
The spatial and movement information from the dorsal stream can inform object recognition and identification in the ventral stream.
The dorsal and ventral streams are two pathways in the brain involved in visual processing. The dorsal stream processes spatial location and movement (обрабатывает пространственное местоположение и движение), while the ventral stream processes visual characteristics and object identity. They collaborate to provide a understanding of visual perception, with the dorsal stream focusing on “where” information and the ventral stream on “what” information.
Visual object agnosia
a condition in which an individual has difficulty identifying or recognizing objects based on visual perception. This typically results from damage to the ventral stream of processing in the brain’s occipital and temporal lobes. People with visual object agnosia can often perceive colors and shapes but can’t synthesize this information into a perception that allows them to identify a specific object. can reach and grasp objects that they cannot recognize
Visual object agnosia is divided into apperceptive agnosia and associative agnosia.
Optic ataxia (Оптическая атаксия)
a neurological condition characterized by a deficit in visually guided hand movements (зрительно управляемых движений рук). Individuals have trouble reaching for objects using visual guidance, particularly when reaching towards objects in their peripheral vision. Occurs when damage to the parietal lobe of the brain, specifically in areas associated with the dorsal stream of visual processing (the “where” or “how” pathway).
Patients can identify objects visually and have normal strength and coordination.
Optic ataxia is one of the components of a syndrome known as Balint’s syndrome, which also includes simultanagnosia - difficulty perceiving the visual field (поля зрения) as a whole; and ocular apraxia - difficulty voluntarily moving the eyes (произвольным движением глаз).
Vision for knowledge and vision for action
Vision for Knowledge:
Associated with the ventral stream (from V1 to temporal lobe).
Focuses on perceiving and understanding the visual world.
Involves object recognition, perception of shapes, colors, and faces, and extracting (извлечение) meaning from visual stimuli.
Vision for Action:
Associated with the dorsal stream (from V1 to parietal lobe).
Guides and executes (выполняет) motor actions based on visual information.
Processes spatial location, movement, and interaction with the environment.
Depth Perception
It refers to our ability to perceive and understand the spatial relationships and distances (пространственные соотношения и расстояния) between objects in a three-dimensional (3D) world.
It allows us to gauge the relative distance (измерять относительное расстояние) of objects from ourselves and from each other.
Depth perception is vital for tasks such as judging distances, perceiving the layout (расположения) of our surroundings, and interacting with objects in the environment.
Восприятие глубины возникает из множества сигналов глубины. Обычно они подразделяются на бинокулярные сигналы, которые основаны на получении сенсорной информации в трех измерениях от обоих глаз, и на монокулярные сигналы, которые могут быть представлены только в двух измерениях и наблюдаются только одним глаз.
Occlusion
is a depth cue (индикатор глубины) that occurs when one object partially blocks or obscures (затемняет) another object.
When an object occludes another, the occluded object is perceived as being farther away (находящийся дальше).
This depth cue provides important information about the relative (относительных) positions and distances of objects.
Importance of Occlusion:
Occlusion is a powerful depth cue that helps us perceive the spatial layout (расположение) of objects
in relation to one another.
It provides depth information by indicating which objects are closer or farther away based on their overlap or occlusion.
By detecting occlusion, our visual system can infer the relative depth order of objects and create a sense of depth perception.
In summary, depth perception is our ability to perceive and understand the spatial relationships (пространственные соотношения) and distances between objects in a 3D world.
