Feeling Neglected

 

What do you notice about the pictures below?

Drawing of scene

(http://www.acbrown.com/neuro/Lectures/Assc/NrAsscPrtl.htm )

Obviously, the “copies” of the original drawings are incomplete.  More specifically, they are missing their left halves.  This is an effect of a condition called contralateral neglect, which is a result of damages/lesions to the right parietal lobe (Wede, 2014).  Victims of this condition unconsciously neglect the world to their left.  This lack of attention spans from drawings like the ones above, to bathing only one side of the body, eating only half of a plate of food, and brushing only one side of teeth within the mouth (Wede, 2014).

 

(http://www.neuroskills.com/brain-injury/parietal-lobes.php)

Aside from receiving sensory information such as touch and temperature, the parietal lobe is responsible for visual tasks, such as mapping (Anon., 2014).  The visual/mapping skills pertain more so to the right parietal lobe, which is where contralateral neglect comes into play.  Along with visually mapping our surroundings, the parietal lobe also maps out our bodies (Freudenrich, Boyd, 2001).   It is this that allows us to know if something is touching us, an instant description of this something (sharp, hot, wet, etc), and most importantly in this case, where it is touching us.

When our brain cannot receive proper sensory information from the left side of the body, it is as if the left side does not exist; this leads contralateral neglect sufferers to behave as such, in ways like those relayed above (Anon., 2001).  To summarize an example given by British neurologist W. R. Brain, subjects now known to have suffered from contralateral neglect would frequently get lost in their own homes.  They would repeatedly make right turns throughout hallways, or choose to enter/exit doors only on their rights (Anon., 2001 [Brain, 1941]).  According to Brain’s research, some people can acknowledge the existence of the left sides of their bodies, while others live in denial of its existence due to lack of sensory “evidence.”

The following is a series of paintings done by stroke sufferer Anton Raederscheidt, who displayed neglect.  You can see the improvement in his spatial skills through his self-portraits over time (Anon., 2001).

(www.ib.cnea.gov.ar)

Contralateral neglect deals not only with attentional processing, but also displays what we call localization of function, or how “specific functions are served by specific areas of the brain” (Goldstein, 29).  The fact that damage to a specific area (in this case, the right parietal lobe) causes consistent results (neglecting the left half of the world, no sensory information received from left half of body, poor mapping skills) demonstrates exactly what localization defines.  This condition also provides insight into how the brain processes the objects we attend to.  It has been acknowledged across a number of studies that many areas of the brain are involved with attentional processing, and “attentional processing enhances neural responses” (Wede, 2014).  Basically, even though visual information may be attended to by areas all over the brain, the right parietal lobe seems to be of extreme importance in this realm.

The right parietal lobe within the brain is responsible for receiving sensory information like touch, along with mapping out visual information we receive.  This mapping ability not only applies to our surroundings, but also to the different parts of our bodies.  When the right parietal lobe is damaged, our spatial and sensory knowledge becomes less accurate.  Known as contralateral neglect, this condition causes its victims to mind only the right side of the world, neglecting the left side of the body and surrounding area.  This bizarre condition provides evidence for localization of function within the brain, and gives us more interest in learning about the power and complexity which exists inside of our own bodies.

 

RESOURCES

Anon. “Lesions of the Parietal Association Cortex: Deficits of Attention” NCBI 2001 <http://www.ncbi.nlm.nih.gov/books/NBK10998/ >

Anon. “Parietal Lobes” Centre for Neuro Skills 2014 <http://www.neuroskills.com/brain-injury/parietal-lobes.php>

Wede, Joshua. “Physiological Underpinnings of Attentional Processing” Psych256: Introduction to Cognitive Psychology 2014     <https://courses.worldcampus.psu.edu/sp14/psych256/001/content/05_lesson/12_page.html>

Goldstein, Bruce E. Cognitive Psychology: Connecting Mind, Research, and Everyday Experience. Belmont: Wadsworth, Cengage Learning, 2011, 2008.

Freudenrich, Ph.D., Craig, and Robynne Boyd.  “How Your Brain Works” HowStuffWorks.com. 06 June 2001.  <http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain.htm>

2 thoughts on “Feeling Neglected

  1. Stacey Dian Brantley

    Your blog post on contralateral neglect was both interesting and informative. In gaining further insight into the condition, I was intrigued to find out what types of treatment if any were available to those who are afflicted.

    According to the Journal of Neurology, Neurosurgery and Psychiatry, hemispatial neglect is an extremely common and equally challenging neuropsychological condition that follows unilateral brain damage, most usually of the right hemisphere. Although the cause of neglect can be from various pathological conditions, it is most often seen due to lesions caused after stroke or hemorrhage. Patients with cerebral lesions involving the posterior-inferior parietal and the premotor cortex, most often in the right hemisphere, sometimes fail to explore the extra-personal and personal sectors of space contralateral to the side of the lesion, are not aware of the stimuli presented in these portions of space, or of contralateral body parts and their disordered function. (Vallar).

    Due to the heterogeneous nature of both the condition and the patients who suffer from it, no single treatment of hemispatial neglect has proven effective. Attempts at pharmacological treatment have shown only mixed results while behavioral studies using conditioning, sensory stimulation or sensory depravation has fared only slightly better showing short-term improvement. The most promising form of rehabilitation has been reported with prism adaptation therapy.

    Prism adaptation therapy, the benefits of which were first reported by Rosetti, et al, is an inexpensive, simple to administer treatment that appears to be free of side effects and has shown to be effective for relatively long-term improvement. During therapy, an individual wears special prismatic goggles that displace the visual field either laterally or vertically in a rightward or leftward direction; they then engage in the perceptual motor task of pointing to a visual target directly in front of them. Initially, the prisms will cause subjects to misreach for the target, however during adaptation training they learn to correct the reach trajectory. In their article ‘Neglect Syndrome’, Springer.com reports “twenty-minute sessions of prism adaptation delivered twice per day for 2 weeks led to improved performance in patients with neglect. Improvement lasted for up to 17 weeks. Follow-up studies indicate that prism adaptation may facilitate recovery after treatment ends and that gains may generalize to other activities of daily living.”

    While no two injuries to the brain are alike and each patients experience of hemispatial neglect varies greatly, it appears that prism adaptation therapy offers promise as a form of rehabilitation for some.

    WORKS CITED:

    Mennemeier M.: Neglect Syndrome. In: Caplan B., DeLuca J., Kreutzer J. (Ed.) Encyclopedia of Clinical Neuropsychology: SpringerReference (www.springerreference.com). Springer-Verlag Berlin Heidelberg, 2011. DOI: 10.1007/SpringerReference_184105 2011-05-09 09:18:39 UTC. Web. 29 Mar. 2014.

    Parton, A., Mahorta, P., Husain, M., ‘Hemispatial Neglect.’ Journal of Neurology, Neurosurgery and Psychiatry 75.1 (2004): n. pag. Web. 29 Mar. 2014.

    United States Nat’l. Library of Medicine, Nat’l. Institutes of Health, ‘Spatial hemineglect in humans’ by Vallar, G., 1998 Mar. 1. Web. 29 Mar. 2014.

    Wikipedia contributors. “Prism adaptation.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 15 Jan. 2014. Web. 30 Mar. 2014.

  2. Julie Hall

    Contralateral neglect is an interesting condition and supports the idea of localization of function. The parietal lobe is involved in representing visual space and directing attention. Brain scans support the idea that neurons fire in the right parietal lobe in response to stimuli on the both sides, but the left parietal lobe only reacts to stimuli on the right side. This helps explain way patients with damage to the right parietal lobe may neglect the environment and their body on the left side.
    http://www.ncbi.nlm.nih.gov/books/NBK10998/figure/A1807/?report=objectonly

    As you mentioned, the degree of inattention can vary with some patients unaware of items or people and others neglecting the left side of their body when they have the physical motor skills to attend to them (dressing themselves, drawing, etc.). As noted in the text, parietal lobe lesions can damage the action pathway, preventing patients from correctly performing “the task that combines vision and action” (Goldstein, 2011, p. 74). This is demonstrated by Peggy’s attempt to draw, http://www.youtube.com/watch?v=ymKvS0XsM4w. It is interesting to see that Peggy acknowledges the missing left side when it is pointed out and that the neglect was projected to memory and not just current interactions.

    Treatment for contralateral neglect is still being researched and tested. Patients that are aware of their condition may be trained to attend to stimuli, success has been limited as many patients are not aware and those that are rarely transfer the training task to task. Another method is physically maneuvering a patient to attend to surroundings. Awareness has improved in cases where the patient’s body was turned to the left while keeping the head and eyes straight, adjusting what the patient’s mind perceived as the body’s midpoint. While treatments and understanding of the condition have improved there is still much work to be done in the field.

    References

    Cogmonaut. (2011, February 17). A visual neglect patient [Video file]. Retrieved from http://www.youtube.com/watch?v=ymKvS0XsM4w

    Goldstein, E. Bruce, (2011). Cognitive Psychology: Connecting Mind, Research, and Everyday Experience (3rd ed.). Belmont, CA: Wadsworth, Cengage Learning.

    Parton A, Malhotra P, Husain M. (2003, August 6). Hemispatial Neglect. Journal of Neurology, Neurosurgery & Psychiarty. Retrieved from http://jnnp.bmj.com/content/75/1/13.full

    Purves D, Augustine GF, Fitzpatrick D, et al., editors. Sunderland (MA): Sinauer Associates. (2001). Lesions of the Parietal Association Cortex: Deficits of Attention. NCBI. Retrieved from http://www.ncbi.nlm.nih.gov/books/NBK10998/

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