+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

How low can you go: spatial frequency sensitivity in a patient with pure alexia

How low can you go: spatial frequency sensitivity in a patient with pure alexia

Brain and Language 126(2): 188-192

Pure alexia is a selective deficit in reading, following lesions to the posterior left hemisphere. Writing and other language functions remain intact in these patients. Whether pure alexia is caused by a primary problem in visual perception is highly debated. A recent hypothesis suggests that a low level deficit - reduced sensitivity to particular spatial frequencies - is the underlying cause. We tested this hypothesis in a pure alexic patient (LK), using a sensitive psychophysical paradigm to examine her performance with simple patterns of different spatial frequency. We find that both in a detection and a classification task, LK's contrast sensitivity is comparable to normal controls for all spatial frequencies. Thus, reduced spatial frequency sensitivity does not constitute a general explanation for pure alexia, suggesting that the core deficit in this disorder is at a higher level in the visual processing stream.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 036936685

Download citation: RISBibTeXText

PMID: 23774289

DOI: 10.1016/j.bandl.2013.05.006

Related references

Neuro psychology of pure alexia a case of pure alexia in a patient who had occipital lobectomy. Psychiatria et Neurologia Japonica 70(8): 689-700, 1968

Music alexia in a patient with mild pure alexia: disturbed visual perception of nonverbal meaningful figures. Cortex 33(1): 187-194, 1997

Fusiform type alexia: pure alexia for words in contrast to posterior occipital type pure alexia for letters. Journal of the Neurological Sciences 247(1): 81-92, 2006

On pure alexia--a case of pure alexia following occipital lobectomy. Seishin Shinkeigaku Zasshi 70(8): 689-700, 1968

Pure alexia from impaired visuo spatial perception. Neurology 31(4 Part 2): 82, 1981

Pure alexia for kana. Characterization of alexia with lesions of the inferior occipital cortex. Journal of the Neurological Sciences 268(1-2): 48-59, 2008

Nonconvulsive status epilepticus manifesting as pure alexia (alexia without agraphia). Epilepsy and Behavior 10(4): 626-628, 2007

Pure alexia in a patient with multiple sclerosis. Neurological Sciences 38(3): 511-513, 2017

Visual command hallucinations in a patient with pure alexia. Journal of Neurology Neurosurgery and Psychiatry 75(1): 80-86, 2004

Neurolinguistic features during recovery of a Chinese patient with pure alexia. Nan Fang Yi Ke Da Xue Xue Bao 33(5): 713-718, 2013

Pure alexia and word-meaning deafness in a patient with multiple sclerosis. Archives of Neurology 55(11): 1473-1474, 1998

Development of pure alexia due to a lesion in the left fusiform gyrus in a patient with hypertrophic pachymeningitis. Brain and Nerve 61(9): 1075-1077, 2009

Central visual fields in pure alexia "without hemianopsia"--visual dysfunction in the right hemifield, and alexia for "kana" words in the left. Rinsho Shinkeigaku 31(10): 1083-1089, 1991

Pure alexia in Japanese and agraphia without alexia in kanji. The ability dissociation between reading and writing in kanji vs kana. Archives of Neurology 45(10): 1157-1159, 1988