VISUAL PATHWAYS AND AGNOSIA

The dorsal pathway processes information about spatial location and movement, allowing us to interact with the world. It's like a GPS system for our actions.

The ventral pathway is responsible for recognizing objects, their features, and their meaning. It's like the brain's 'what' department.

A condition where a person has difficulty recognizing objects despite having normal vision. They might struggle to name or identify objects, even though they can see them.

A type of visual agnosia where a person cannot recognize faces. They may be able to see the face, but they can't tell who the person is.

A condition where a person has difficulty reaching for and interacting with objects, despite being able to see them. They may misjudge distances and struggle with tasks like threading a needle.

A rare condition where a person can only perceive one stimulus at a time. They may struggle to see the whole picture, only focusing on individual details.

A category-specific visual agnosia where someone has difficulty recognizing objects, but can still recognize faces. This suggests that different parts of the brain may be involved in recognizing different types of objects.

A category-specific visual agnosia characterized by a difficulty in recognizing faces, although other types of visual objects can be recognized. It is a challenge for the brain to recognize patterns of features that together form a person's identity.

The ability to recognize an object's shape, regardless of its size, distance, or orientation. For example, recognizing a chair as a chair, even if it is upside down or far away.

A disorder where individuals struggle to recognize faces, even those of familiar people, including their own. They might rely on secondary cues like clothing or voice.

A type of visual agnosia where individuals struggle to recognize places, even though they may have the ability to remember them after verbal descriptions.

A visual processing stage where features like color, depth, and shape are combined to form recognizable shapes. This helps distinguish between objects based on their overall form.

A visual agnosia where individuals struggle to identify, name, or associate colors with objects. This is distinct from achromatopsia which is a complete inability to perceive color.

A visual processing stage where groupings of features are formed based on alignment or straight lines, helping to identify object edges and boundaries.

Assessment steps for visual agnosia involve a comprehensive evaluation of cognitive and visual processing abilities, including tasks related to shape perception, object recognition, and spatial awareness.

Treatments for visual agnosia aim to target specific deficits, taking into account the nature and extent of the brain damage. Strategies include compensatory approaches and restorative therapies.

The inability to recognize and name objects due to a disruption in the processing of visual information, even without sensory deficits. It affects only the visual modality. Patients can describe features of objects but cannot recognize the overall object.

The inability to integrate individual parts of a visual stimulus into a complete, coherent perception, resulting in difficulties recognizing objects as a whole. This is distinct from recognizing individual features like shape or color.

A type of agnosia where a visual stimulus can be perceived as a whole, but the patient cannot identify it as a specific object. This suggests a problem in linking the visual percept to stored knowledge of the object.

Inability to form links between the perceived object and stored semantic information. This means patients can see an object, but they cannot remember its name, purpose, or how it's used.

Patients with this type of agnosia can differentiate between objects but cannot identify them. They can copy drawings and may even sort objects by category, but they lack the ability to name objects.

Presenting a linear drawing instead of the real object, overlapping multiple images of objects in space, or showing incomplete, masked, or degraded images, unusual perspectives, or silhouettes can exacerbate recognition deficits in apperceptive agnosia.

Individuals with apperceptive agnosia struggle to follow the contours of objects with their fingers and make copies of drawings. This highlights their difficulty in forming a coherent perception.

Patients with apperceptive agnosia can draw objects from memory since the stored knowledge relating to the visual aspects of the object remains intact.

A cognitive model that describes the steps involved in recognizing and naming objects, including potential failures in apperceptive and associative agnosia. This model outlines different stages of processing, from visual perception to semantic knowledge.

Prosopagnosia that is present from birth and persists throughout life.

Prosopagnosia that develops after a brain injury or stroke.

A type of acquired prosopagnosia characterized by difficulty processing facial features.

A type of acquired prosopagnosia characterized by difficulty connecting visual face information with memories about the person.

A brain region located in the fusiform gyrus, involved in face recognition.

The idea that there are two separate pathways for face recognition: one for conscious recognition and one for unconscious processing.

A psychological disorder where a person believes a familiar person has been replaced by an identical impostor.

The inability to recognize sounds, despite normal hearing ability.

A type of prosopagnosia characterized by a lack of emotional response to familiar faces.

A type of prosopagnosia characterized by a conscious inability to recognize faces, but with underlying unconscious processing of facial information.

A brain area involved in face processing, located in the occipital lobe.

A brain area involved in face processing, located in the anterior temporal lobe.

A bundle of nerve fibers that connects the occipital and temporal lobes, important for face processing.

A type of therapy for prosopagnosia that focuses on training visual features, face matching, and name association.

The inability to recognize objects by touch despite having normal somatosensory abilities.

The ability to perceive and manipulate the world, including spatial relationships and mental rotation.

Indicates what actions can be performed with an object, regardless of its visual features.

A neuropsychological syndrome involving optic ataxia, simultanagnosia, and oculomotor apraxia.

Paralysis of eye fixation, making it difficult to voluntarily look into the peripheral visual field.

Higher-level processing that relies heavily on visual perception and experience.

A rare neurological syndrome marked by four specific deficits: finger agnosia (inability to recognize individual fingers), agraphia (difficulty writing), acalculia (difficulty with math), and left-right disorientation. This syndrome is typically associated with damage to the left angular gyrus in the brain.

A condition where individuals are unaware of their own disabilities. This can occur with various neurological disorders and often accompanies Simultanagnosia.

A condition resulting from damage to the right angular gyrus (inferior parietal lobe), causing individuals to neglect the left side of their bodies and the left half of their environment.

The concept that individual parts of the brain specialize in different functions, but these functions are not completely independent. There is ongoing communication and interaction between different brain areas.