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Dorsal and ventral stream interaction: contributions from optic ataxia.
J Cogn Neurosci. 2005 Apr; 17(4):632-40.JC

Abstract

In monkeys and humans, two functionally specialized cortical streams of visual processing emanating from V1 have been proposed: a dorsal, action-related system and a ventral, perception-related pathway. Traditionally, a separate organization of the two streams is assumed; the extent of functional interaction is unknown. After lesions of the dorsal stream in patients with optic ataxia, it has recently been shown that the ventral perception-related system might contribute to visuomotor processing if movements rely on remembered target positions. The ventral pathway thus seemed to participate in goal-directed movements, a function that previously has been assigned exclusively to the dorsal stream. We wondered whether different types of pointing movements are controlled by switching between two separated cortical pathways or whether a variable interaction of interconnected systems should be assumed. Our study investigated two acute stroke patients with optic ataxia following lesions of the dorsal stream in a delayed pointing task. The delays ranged from 0 to 10 sec. The patients' pointing error decreased in a linear manner with the length of time. The finding suggests a gradual change between dorsal and ventral control of reaching behavior, rather than a sudden switch between two separated cortical processing streams. Although our observations with two patients require further validation, the results suggest that the ventral and dorsal systems interact closely in the sensorimotor control of reaching behavior.

Authors+Show Affiliations

Section Neuropsychology, Department of Cognitive Neurology, University of Tübingen, Germany. marc.himmelbach@uni-tuebingen.deNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15829083

Citation

Himmelbach, Marc, and Hans-Otto Karnath. "Dorsal and Ventral Stream Interaction: Contributions From Optic Ataxia." Journal of Cognitive Neuroscience, vol. 17, no. 4, 2005, pp. 632-40.
Himmelbach M, Karnath HO. Dorsal and ventral stream interaction: contributions from optic ataxia. J Cogn Neurosci. 2005;17(4):632-40.
Himmelbach, M., & Karnath, H. O. (2005). Dorsal and ventral stream interaction: contributions from optic ataxia. Journal of Cognitive Neuroscience, 17(4), 632-40.
Himmelbach M, Karnath HO. Dorsal and Ventral Stream Interaction: Contributions From Optic Ataxia. J Cogn Neurosci. 2005;17(4):632-40. PubMed PMID: 15829083.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Dorsal and ventral stream interaction: contributions from optic ataxia. AU - Himmelbach,Marc, AU - Karnath,Hans-Otto, PY - 2005/4/15/pubmed PY - 2005/6/18/medline PY - 2005/4/15/entrez SP - 632 EP - 40 JF - Journal of cognitive neuroscience JO - J Cogn Neurosci VL - 17 IS - 4 N2 - In monkeys and humans, two functionally specialized cortical streams of visual processing emanating from V1 have been proposed: a dorsal, action-related system and a ventral, perception-related pathway. Traditionally, a separate organization of the two streams is assumed; the extent of functional interaction is unknown. After lesions of the dorsal stream in patients with optic ataxia, it has recently been shown that the ventral perception-related system might contribute to visuomotor processing if movements rely on remembered target positions. The ventral pathway thus seemed to participate in goal-directed movements, a function that previously has been assigned exclusively to the dorsal stream. We wondered whether different types of pointing movements are controlled by switching between two separated cortical pathways or whether a variable interaction of interconnected systems should be assumed. Our study investigated two acute stroke patients with optic ataxia following lesions of the dorsal stream in a delayed pointing task. The delays ranged from 0 to 10 sec. The patients' pointing error decreased in a linear manner with the length of time. The finding suggests a gradual change between dorsal and ventral control of reaching behavior, rather than a sudden switch between two separated cortical processing streams. Although our observations with two patients require further validation, the results suggest that the ventral and dorsal systems interact closely in the sensorimotor control of reaching behavior. SN - 0898-929X UR - https://www.unboundmedicine.com/medline/citation/15829083/Dorsal_and_ventral_stream_interaction:_contributions_from_optic_ataxia_ L2 - https://www.mitpressjournals.org/doi/10.1162/0898929053467514?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -