TY  - JOUR
A1  - Hautzel, H.
A1  - Taylor, J. G.
A1  - Krause, B. J.
A1  - Schmitz, N.
A1  - Tellmann, L.
A1  - Ziemons, Karl
A1  - Shah, N. J.
A1  - Herzog, H.
A1  - Müller-Gärtner, H.-W.
T1  - The motion aftereffect: more than area V5/MT? Evidence from 15O-butanol PET studies
JF  - Brain Research
N2  - The motion aftereffect is a perceptual phenomenon which has been extensively investigated both psychologically and physiologically. Neuroimaging techniques have recently demonstrated that area V5/MT is activated during the perception of this illusion. The aim of this study was to test the hypothesis if a more broadly distributed network of brain regions subserves the motion aftereffect. To identify the neuronal structures involved in the perception of the motion aftereffect, regional cerebral blood flow (rCBF) measurements with positron emission tomography were performed in six normal volunteers. Data were analysed using SPM96. The motion-sensitive visual areas including area V5/MT were activated in both hemispheres. Additionally, the lateral parietal cortex bilaterally, the right dorsolateral prefrontal cortex, the anterior cingulate cortex and the left cerebellum showed significant increases in rCBF values during the experience of the waterfall illusion. In a further reference condition with identical attentional demand but no perception of a motion aftereffect elevated rCBF were found in these regions as well. In conclusion, our findings support the notion that the perceptual illusion of motion arises exclusively in the motion-sensitive visual area V5/MT. In addition, a more widespread network of brain regions including the prefrontal and parietal cortex is activated during the waterfall illusion which represents a non-motion aftereffect-specific subset of brain areas but is involved in more basic attentional processing and cognition.
Y1  - 2001
SN  - 0006-8993
VL  - 892
IS  - 2
SP  - 281
EP  - 292
ER  - 
TY  - JOUR
A1  - Taylor, J. G.
A1  - Schmitz, N.
A1  - Ziemons, Karl
A1  - Grosse-Ruyken, M.-L.
A1  - Gruber, O.
A1  - Müller-Gärtner, H.-W.
A1  - Shah, N. J.
T1  - The network of brain areas involved in the motion aftereffect
JF  - Neuroimage
N2  - A network of brain areas is expected to be involved in supporting the motion aftereffect. The most active components of this network were determined by means of an fMRI study of nine subjects exposed to a visual stimulus of moving bars producing the effect. Across the subjects, common areas were identified during various stages of the effect, as well as networks of areas specific to a single stage. In addition to the well-known motion-sensitive area MT the prefrontal brain areas BA44 and 47 and the cingulate gyrus, as well as posterior sites such as BA37 and BA40, were important components during the period of the motion aftereffect experience. They appear to be involved in control circuitry for selecting which of a number of processing styles is appropriate. The experimental fMRI results of the activation levels and their time courses for the various areas are explored. Correlation analysis shows that there are effectively two separate and weakly coupled networks involved in the total process. Implications of the results for awareness of the effect itself are briefly considered in the final discussion.
Y1  - 2000
SN  - 1053-8119
VL  - 11
IS  - 4
SP  - 257
EP  - 270
ER  - 
TY  - JOUR
A1  - Makovicka, C.
A1  - Gärtner, G.
A1  - Hardt, Arno
A1  - Hermann, W.
A1  - Wiechert, D. U.
T1  - Impregnated cathode surface investigations by SFM/STM and SEM/EDX
JF  - Applied surface science. Vol. 111
Y1  - 1997
SN  - 1873-5584 (E-Journal); 0169-4332 (Print)
SP  - 70
EP  - 75
ER  - 
TY  - JOUR
A1  - Fonti, Patrick
A1  - von Arx, Georg
A1  - García-González, Ignacio
A1  - Eilmann, Britta
A1  - Sass-Klaassen, Ute G. W.
A1  - Gärtner, Holger
A1  - Eckstein, Dieter
T1  - Studying global change through investigation of the plastic responses of xylem anatomy in tree rings
JF  - New Phytologist
N2  - Variability in xylem anatomy is of interest to plant scientists because of the role water transport plays in plant performance and survival. Insights into plant adjustments to changing environmental conditions have mainly been obtained through structural and functional comparative studies between taxa or within taxa on contrasting sites or along environmental gradients. Yet, a gap exists regarding the study of hydraulic adjustments in response to environmental changes over the lifetimes of plants. In trees, dated tree-ring series are often exploited to reconstruct dynamics in ecological conditions, and recent work in which wood-anatomical variables have been used in dendrochronology has produced promising results. Environmental signals identified in water-conducting cells carry novel information reflecting changes in regional conditions and are mostly related to short, sub-annual intervals. Although the idea of investigating environmental signals through wood anatomical time series goes back to the 1960s, it is only recently that low-cost computerized image-analysis systems have enabled increased scientific output in this field. We believe that the study of tree-ring anatomy is emerging as a promising approach in tree biology and climate change research, particularly if complemented by physiological and ecological studies. This contribution presents the rationale, the potential, and the methodological challenges of this innovative approach.
Y1  - 2010
U6  - https://doi.org/10.1111/j.1469-8137.2009.03030.x
SN  - 1469-8137 (Online)
SN  - 0028-646X (Print)
VL  - 185
IS  - 1
SP  - 42
EP  - 53
PB  - Wiley-Blackwell
CY  - Oxford
ER  -