Associative agnosia

Associative agnosia

People with associative agnosia fail in assigning meaning to an object, animal or building that they can see clearly. Most cases have injury to the occipital and temporal lobes and the critical site of injury appears to be in the left occipito-temporal region, often with involvement of the splenium of the corpus callosum. The clinical "definition" of the disorder is when an affected person is able to copy/draw things that they cannot recognize. The disorder appears to be very uncommon in a "pure" or uncomplicated form and is usually accompanied by other complex neuropsychological problems such as impaired language or memory. The affected individual may not realize that they have a visual problem and may complain of becoming "clumsy" or "muddled" when performing familiar tasks such as setting the table or simple DIY.

There has been debate about whether the fundamental problem in associative agnosia implicates

*Higher-order visual perception - perhaps in integrating the parts of an object into a structured whole
*A disconnection syndrome - a failure of linking vision and perception with language
*Damage to a modality-specific meaning process (semantic system).

Any or all of these interpretations may be appropriate for an individual patient but the same explanation will not necessarily work for all.

Evidence in favour of the semantic hypothesis can be inferred from studies showing that affected people can often show partial knowledge of the things they cannot recognise - such as knowing that an object is a container but not being able to determine whether it is a jug or a mug. They may also have difficulties in deciding whether two different visual forms (visual synonyms) are "the same" - for example, they may be unable to determine that a wine glass and a tumbler are more alike than a tumbler and a vase.

Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Agnosia — For the Spanish film, see Agnosía. Agnosia Classification and external resources ICD 10 R48.1 ICD 9 …   Wikipedia

  • associative mindblindness —    A term that was coined in or shortly before 1890 by the German neurologist Heinrich Lissauer (1861 1891) to denote the inability to integrate a visual percept with information from the other sensory modalities, entailing a failure of prelin… …   Dictionary of Hallucinations

  • Integrative agnosia — Integrative agnosia, as first defined by Riddoch and Humphreys (1987), leon/mivnim/pdfs/Riddoch%20stm%20in%20integartive%20agnosia.pdf] is the disability to recognize objects due to the inability to group and… …   Wikipedia

  • Visual agnosia — is the inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus and is typified by the inability to recognize familiar objects or faces. This is distinct from blindness, which is a lack of sensory input …   Wikipedia

  • Cognitive neuroscience of visual object recognition — Object recognition is the ability to perceive an object’s physical properties (such as shape, colour and texture) and apply semantic attributes to the object, which includes the understanding of its use, previous experience with the object and… …   Wikipedia

  • Memory disorder — Memory can be defined as an organism s ability to encode, retain, and recall information. Disorders of memory can range from mild to severe, yet are all a result of damage to neuroanatomical structures; either in part or in full. This damage… …   Wikipedia

  • Semantic dementia — (SD) is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non verbal domains. The most common presenting symptoms are in the verbal domain however (with loss of word meaning) and it is… …   Wikipedia

  • Cognitive neuroscience of music — The cognitive neuroscience of music is the scientific study of brain based mechanisms involved in the cognitive processes underlying music. Methods include functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS),… …   Wikipedia

  • Prosopagnosia — Infobox Disease Name = Prosopagnosia Caption = DiseasesDB = ICD10 = ICD9 = ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = MeshID = D020238 Prosopagnosia (sometimes known as face blindness) is a disorder of face perception where the… …   Wikipedia

  • List of psychology topics — This page aims to list all topics related to psychology. This is so that those interested in the subject can monitor changes to the pages by clicking on Related changes in the sidebar. It is also to see the gaps in Wikipedia s coverage of the… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”