Parieto-occipital cortex activation during self-generated eye movements in the dark
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Parieto-occipital cortex activation during self-generated eye movements in the dark. / Law, I; Svarer, C; Rostrup, E; Paulson, O B.
I: Brain, Bind 121 ( Pt 11), 11.1998, s. 2189-200.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Parieto-occipital cortex activation during self-generated eye movements in the dark
AU - Law, I
AU - Svarer, C
AU - Rostrup, E
AU - Paulson, O B
PY - 1998/11
Y1 - 1998/11
N2 - A number of extrastriate visual areas in the parieto-occipital cortex are known from single-cell recordings of the macaque monkey to be involved in the coding of eye-position signals in the brain. These are important for the accurate location of visual objects in extrapersonal space. It can be predicted that these areas will show increased activation during the performance of eye movements at high frequency. In the present study PET and measurements of the regional distribution of cerebral blood flow (rCBF) were used as indirect measures of neural activity. Two independent groups of normal volunteers performed large-amplitude self-generated eye movements in complete darkness, thus removing the confounding effects of visual stimulation on parieto-occipital activation. The first group (group A; n = 5) served as a hypothesis-generating group and the second group (group B; n = 4) served as a hypothesis-testing group. The data were analysed using statistical parametric mapping at a significance level corrected for multiple comparisons (group A, Z > 4.08; group B, Z > 4.04). Significant rCBF increases were found for both groups in the frontal eye fields, supplementary eye fields, cerebellar vermis and putamina/thalami. Additionally, activation was found in the cunei in the posterior bank of the parieto-occipital sulcus. Also, the extraocular muscles were activated and, as a consequence of the partial volume effect, projected to the orbitofrontal cortices. At a less conservative threshold, activation was found close to the intraparietal sulci on the left side (Z = 3.91, P = 0.09) and right side (Z = 3.33, P = 0.42). The locations of these areas were confirmed in group B with reference to high-resolution structural MRI scans. The activation of the parieto-occipital cortex without overt visual stimuli is interpreted as the result of neural activity related to the reception of efferent copies of motor commands and/or the activation of neurons coding for eye position relative to the orbits. These are important constituents for the location and remapping of visual stimuli in space.
AB - A number of extrastriate visual areas in the parieto-occipital cortex are known from single-cell recordings of the macaque monkey to be involved in the coding of eye-position signals in the brain. These are important for the accurate location of visual objects in extrapersonal space. It can be predicted that these areas will show increased activation during the performance of eye movements at high frequency. In the present study PET and measurements of the regional distribution of cerebral blood flow (rCBF) were used as indirect measures of neural activity. Two independent groups of normal volunteers performed large-amplitude self-generated eye movements in complete darkness, thus removing the confounding effects of visual stimulation on parieto-occipital activation. The first group (group A; n = 5) served as a hypothesis-generating group and the second group (group B; n = 4) served as a hypothesis-testing group. The data were analysed using statistical parametric mapping at a significance level corrected for multiple comparisons (group A, Z > 4.08; group B, Z > 4.04). Significant rCBF increases were found for both groups in the frontal eye fields, supplementary eye fields, cerebellar vermis and putamina/thalami. Additionally, activation was found in the cunei in the posterior bank of the parieto-occipital sulcus. Also, the extraocular muscles were activated and, as a consequence of the partial volume effect, projected to the orbitofrontal cortices. At a less conservative threshold, activation was found close to the intraparietal sulci on the left side (Z = 3.91, P = 0.09) and right side (Z = 3.33, P = 0.42). The locations of these areas were confirmed in group B with reference to high-resolution structural MRI scans. The activation of the parieto-occipital cortex without overt visual stimuli is interpreted as the result of neural activity related to the reception of efferent copies of motor commands and/or the activation of neurons coding for eye position relative to the orbits. These are important constituents for the location and remapping of visual stimuli in space.
KW - Adult
KW - Brain/blood supply
KW - Brain Mapping
KW - Cerebrovascular Circulation
KW - Darkness
KW - Eye Movements/physiology
KW - Female
KW - Functional Laterality
KW - Humans
KW - Male
KW - Occipital Lobe/diagnostic imaging
KW - Oculomotor Muscles/physiology
KW - Parietal Lobe/diagnostic imaging
KW - Regional Blood Flow
KW - Tomography, Emission-Computed
U2 - 10.1093/brain/121.11.2189
DO - 10.1093/brain/121.11.2189
M3 - Journal article
C2 - 9827777
VL - 121 ( Pt 11)
SP - 2189
EP - 2200
JO - Brain
JF - Brain
SN - 0006-8950
ER -
ID: 274964636