Hemineglect Group 5: Hans Tim Joey Sumanth COGS 175.

Hemineglect

Group 5:

Hans Tim Joey Sumanth

COGS 175

Outline• What is hemineglect (Tim)• Examples of hemineglect (Tim)• Deepness of Neglect (Hans)• Neuroanatomy (Hans)• Neglect and consciousness (Sumanth)• Neglect and attention (Sumanth)• Artists with neglect (Sumanth)• Neglect and rational thinking (Joey)• Neglect and reality (Joey)• Summary (Joey)

What is Hemineglect?

• Hemineglect is due to right parietal damage and results in contralateral neglect

• When a patient has hemineglect, they do not attend to their left visual field, since it is the right parietal lobe that is damaged

• It is not that the patients cannot see it, it’s simply an inability to attend to it

• They do not know they have it

Examples of Neglect

• Line bisection task

• Cancellation task

• Copying task

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Visual Search Eye Tracking

• Here the subject tries to find the T’s among the other shapes

Gradient of Neglect

• Neglect does not perfectly divide the entire visual field, rather it varies between individuals and the attended to or not attended to portions of the VF does not have sharp boundaries

The Deepness of hemineglect

• Memories are also selectively attended to– For example, a woman who went to the Piazza in

Milan, was asked what she saw when looking at the Pope, she reported only seeing things in her right visual field

• Mirror Agnosia– Occurs in half of neglect patients

Neuroanatomy of Neglect

• Classically, hemineglect has been associated with lesions in the posterior parietal cortex, particularly the inferior parietal lobe (IPL) or tempo-parietal junction(TPJ)

• Also, some researchers agree that damage to subcortical regions are also responsible for neglect, like the thalamus and basal ganglia

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Hemineglect and Consciousness

• It’s not the seat of consciousness, because people with hemineglect are conscious, but their consciousness is dramatically altered.

• Individuals with right parietal damage but symptoms of neglect still failed in many visual working memory tasks (Berryhill 2008)

Hemineglect and Attention• Normal conscious people visually attend to

both the left and right sides, where hemineglect patients attend only to the right

• SPECT (Single photon emission-computed tomography) study. (Jodzio 2008)

• Hypoprofusion @ OFC, Parietal, Striatum, Thalamus.

• These areas together form higher thinking and attentional functions.

• Deficits in cortico-striatothalamo-cortical loop.

Hemi-neglected Art

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Lovis CorinthExpressionism1858-1925Stroke = 1911Damage = R

<-- Pre Stroke

Self-portrait with skeleton, 1896.

Post Stroke Work

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'Piéta', drypoint by Lovis Corinth, 1920

Corinth had a stroke in his right hemisphere in 1911 and his work was not not the same till his death 13 years later.

Apple tree in blossom, 1922

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Difference:Internal vsExternalVisualization?

-Lean-Detail

Alterations to Rational Thinking

• 10% of people with hemineglect have anosognosia– It is a denial of their deficit

Hemineglect Reality

• Hemineglect patients have a different perspective in the world when compared to those with no neglect and normal consciousness

Summary• Neglect is usually a result of damage to parietal areas from stroke.

• This leads to lack of attention and analysis of contralaterial visual field.

• Modification of attention leads to changes in consciousness.

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Questions?

• Treatments: drug treatments and behavioral interventions– Difficult because everyone has varying

degrees due to various parts being damaged

– Small subject pool to help design effective treatment options

Citations• Dietrich, A.  Functional neuroanatomy of altered states of consciousness: the transient hypofrontality hypothesis.  Consciousness and Cognition, 12, 231-

256, 2003.

• Husain, Masud. "Hemineglect." Scholarpedia. 25 Apr. 2007. Institute of Cognitive Neuroscience University College, London. 11 Mar. 2008 http://www.scholarpedia.org/article/Hemineglect.

• Laukkanen, Hannu. "ASSESSMENT AND MANAGEMENT OF NEUROLOGIC UNILATERAL SPATIAL INATTENTION/NEGLECT SYNDROME." 2006. Pacific University College of Optometry. 11 Mar. 2008 <http://images.google.com/imgres?imgurl=http://www.opt.pacificu.edu/ce/catalog/16593-NO/Fig3aNew.jpg&imgrefurl=http://opt.pacificu.edu/ce/catalog/16593-NO/16593-NO.html&h=428&w=432&sz=89&hl=en&start=32&um=1&tbnid=j8RUlwooU1CDKM:&tbnh=125&tbnw=126&prev=/images%3Fq%3Danosognosia%26start%3D20%26ndsp%3D20%26um%3D1%26hl%3Den%26sa%3DN>.

• Ramachandran, V.S. "Parietal Lobes and Neglect." University of California, San Diego. 10 Oct. 2007.

• "Visual Neglect." 12 Nov. 2006. University of Minnesota. 11 Mar. 2008 <http://www.psych.umn.edu/courses/fall06/hes/psy5062/lectures/Lecture11-12-neglect-ppt.pdf>.

• Me, Berryhill, and Olson Ir. "The Right Parietal Lobe is Critical forVisual Working Memory." Neuropsychologia (2008). PubMed. Giesel S&E,La Jolla. 11 Mar. 2008. Keyword: visual neglect.

• K, Jodzio, Lass P, Nyka W, Gasecki D, Bandurski T, and Scheffler J."Cerebral Blood Flow SPECT Imaging in Right Hemisphere-DamagedPatients with Hemispatial Neglect. a Pilot Study." Neuropsychologia(2008). PubMed. Giesel S&E, La Jolla. 11 Mar. 2008. Keyword: bloodflow, visual neglect.

• H, Bazner, and Hennerici Mg. "The Consequences of Stroke for theArtist Lovis Corinth." Dev Med Child Neurol (2006). PubMed. GieselS&E, La Jolla. 11 Mar. 2008. Keyword: artists, neglect.