This file was created by the Typo3 extension sevenpack version 0.7.14 --- Timezone: CEST Creation date: 2013-05-21 Creation time: 20-13-29 --- Number of references 11 article FischerLBB2011 Cerebral Cortex 2012 4 22 4 865-876 Motion processing regions apart from V5+/MT+ are still relatively poorly understood. Here, we used functional magnetic resonance imaging to perform a detailed functional analysis of the recently described cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex. We used distinct types of visual motion stimuli to compare CSv with V5/MT and MST, including a visual pursuit paradigm. Both V5/MT and MST preferred 3D flow over 2D planar motion, responded less yet substantially to random motion, had a strong preference for contralateral versus ipsilateral stimulation, and responded nearly equally to contralateral and to full-field stimuli. In contrast, CSv had a pronounced preference to 2D planar motion over 3D flow, did not respond to random motion, had a weak and nonsignificant lateralization that was significantly smaller than that of MST, and strongly preferred full-field over contralateral stimuli. In addition, CSv had a better capability to integrate eye movements with retinal motion compared with V5/MT and MST. CSv thus differs from V5+/MT+ by its unique preference to full-field, coherent, and planar motion cues. These results place CSv in a good position to process visual cues related to self-induced motion, in particular those associated to eye or lateral head movements. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://cercor.oxfordjournals.org/content/22/4/865.full.pdf+html 10.1093/cercor/bhr154 efischerEFischer nikosNKLogothetis hhbHHBülthoff abartelsABartels article FischerBLB2012 Neuron 2012 3 73 6 1228-1240 Little is known about mechanisms mediating a stable perception of the world during pursuit eye movements. Here, we used fMRI to determine to what extent human motion-responsive areas integrate planar retinal motion with nonretinal eye movement signals in order to discard self-induced planar retinal motion and to respond to objective (“real”) motion. In contrast to other areas, V3A lacked responses to self-induced planar retinal motion but responded strongly to head-centered motion, even when retinally canceled by pursuit. This indicates a near-complete multimodal integration of visual with nonvisual planar motion signals in V3A. V3A could be mapped selectively and robustly in every single subject on this basis. V6 also reported head-centered planar motion, even when 3D flow was added to it, but was suppressed by retinal planar motion. These findings suggest a dominant contribution of human areas V3A and V6 to head-centered motion perception and to perceptual stability during eye movements. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.sciencedirect.com/science/article/pii/S0896627312001407 10.1016/j.neuron.2012.01.022 efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels article 6095 Journal of Vision 2009 5 9 5:14 1-16 Trichromatic color vision is a fundamental aspect of the visual system shared by humans and non-human primates. In human observers, color has been shown to facilitate object identification. However, little is known about the role that color plays in higher level vision of non-human primates. Here, we addressed this question and studied the interaction between luminance- and color-based structural information for the recognition of natural scenes. We present psychophysical data showing that both monkey and human observers equally profited from color when recognizing natural scenes, and they were equally impaired when scenes were manipulated using colored noise. This effect was most prominent for degraded image conditions. By using a specific procedure for stimulus degradation, we found that the improvement as well as the impairment in visual memory performance is due to contribution of image color independent of luminance-based object information. Our results demonstrate that humans as well as non-human primates exploit their sensory ability of color vision to achieve higher performance in visual recognition tasks especially when shape features are degraded. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis http://journalofvision.org/9/5/14/ Biologische Kybernetik Max-Planck-Gesellschaft en 10.1167/9.5.14 sliebeSLiebe efischerEFischer nikosNKLogothetis gregorGRainer article 4939 Cancer Research 2004 8 1 64 5-5 Ataxia telangiectasia (AT) is a hereditary human disorder resulting in a wide variety of clinical manifestations, including progressive neurodegeneration, immunodeficiency, and high incidence of lymphoid tumors. Cells from patients with AT show genetic instability, hypersensitivity to radiation, and a continuous state of oxidative stress. Oxidative stress and genetic instability, including DNA deletions, are involved in carcinogenesis. We examined the effect of dietary supplementation with the thiol-containing antioxidant N-acetyl-L-cysteine (NAC) on levels of oxidative DNA damage and the frequency of DNA deletions in Atm-deficient (AT-mutated) mice. We confirmed that Atm-deficient mice display an increased frequency of DNA deletions (Bishop et al., Cancer Res 2000;60:395). Furthermore, we found that Atm-deficient mice have significantly increased levels of 8-OH deoxyguanosine, an indication of oxidative DNA damage. Dietary supplementation with NAC significantly reduced 8-OH deoxyguanosine level and the frequ ency of DNA deletions in Atm-deficient mice. These levels were similar to the levels in wild-type mice. Our findings demonstrate that NAC counteracts genetic instability and suggest that genetic instability may be a consequence of oxidative stress in Atm-deficient mice. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://cancerres.aacrjournals.org/cgi/content/full/64/15/5148 Biologische Kybernetik Max-Planck-Gesellschaft en RHSchiestl efischerEFischer RReliene poster 7096 2010 12 http://www.kyb.tuebingen.mpg.de/fileadmin/user_upload/files/publications/WSnips2010_[0].pdf http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Schölkopf http://nips.cc/Conferences/2010/Program/event.php?ID=2002 Biologische Kybernetik Max-Planck-Gesellschaft Whistler, BC, Canada NIPS 2010 Workshop on Learning and Planning from Batch Time Series Data en jsheltonJAShelton blaschkoMBBlaschko arthurAGretton JMüller efischerEFischer abartelsABartels poster 7056 2010 11 40 74.11 The model of “predictive coding” suggests that feedback from a higher- to a lower-order visual area carries predictions of lower-level neural activities, whereas the feedforward connections carry the residual errors between the predictions and the actual lower-level activities (Rao and Ballard, 1999). We tested this theory in context of processing of planar motion in early (foveal) visual cortex. In a 2x2 factorial design, human subjects either fixated (eyes still) or carried out smooth pursuit on a display containing a planar random dot-field that was either stationary or moving coherently in-plane. This led to four conditions: (a) fixation on static dot-field, (b) fixation on moving dot-field, (c) pursuit on static dot-field, (d) pursuit of moving dot-field (pursuit was locked to the dot-motion). Neural activity was measured using fMRI at 3T. If early visual cortex coded for retinal motion, (b) and (c) would be expected to activate early visual cortex equally, and more than (a) and (d). In contrast, predictive coding would result in different responses. In addition to the above, early visual cortex would also code the error signal for mismatches between retinal motion input and the prediction for retinal motion, based on e.g. pursuit-related efferent copies. Such mismatches between prediction and input would occur in (b) (retinal motion without prediction of it) and in (d) (absence of retinal motion despite prediction of it). Note that these mismatches are equivalent to the presence of objective motion in the display. Thus, predictive coding would lead to highest responses in (b) (error + input), medium responses in (c) (input only) and (d) (error only), and lowest response in (a). We found (across the whole brain) the only activity satisfying these criteria in the occipital poles. The occipital poles contain the foveal confluence of early visual areas V1-V3, and are thus the key candidate for the above hypothesis. Their responses matched the hypothesized pattern precisely. In contrast, activity in motion responsive areas such as V5/MT+ and parietal regions was mainly driven by eye-movements and by retinal motion. Offline eye-tracking revealed that our results cannot be explained by differential fixation accuracies across conditions. It remains to be elucidated whether predictive coding actually accounts for the results, or whether direct feedback of objective motion signals from higher-level areas sums up with retinal input to the response observed in the occipital pole. Nevertheless, our results let us conclude that activity in the foveal representation of the early visual cortex fully match the predictions of Rao and Ballard (1999) for predictive coding. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.sfn.org/am2010/index.aspx?pagename=abstracts_main Biologische Kybernetik Max-Planck-Gesellschaft San Diego, CA, USA 40th Annual Meeting of the Society for Neuroscience (Neuroscience 2010) en efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels poster FischerBLB2010 Perception 2010 8 39 ECVP Abstract Supplement 95 Motion processing regions apart from V5+/MT+ are still relatively poorly understood. The cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex (dPCC) was previously described to respond preferentially to coherent motion and implied in ego-motion processing. We used fMRI to compare responses of CSv/dPCC and of areas V5/MT and MST to distinct types of motion and self-motion cues such as retinal motion and objective motion, determined during pursuit. Both V5/MT and MST had a strong preference for contra- versus ipsi-lateral stimulation, no preference for 2D planar motion versus 3D flow, and reduced yet significant responses to random motion. In contrast, CSv/dPCC preferred 2D planar motion over 3D flow, showed no lateralization, and did not respond to random motion. All areas responded strongly to eye-movement related signals, however CSv responded more to ‘real’ motion than to retinal motion while the reverse was the case for V5/MT and MST. CSv/dPCC thus differs from other motion-responsive regions by its unique preference to full-field, coherent and planar motion cues and its enhanced capability to respond to real motion. These results place CSv/dPCC in a good position to process visual and non-visual cues related to self-induced motion, especially those associated to eye-movements. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.perceptionweb.com/abstract.cgi?id=v100307 Lausanne, Switzerland 33rd European Conference on Visual Perception efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels poster 6162 2009 10 39 558.21 Self- and object-motion processing greatly relies on visual cues. There are at least two entirely independent kinds of self-induced visual motion that combine to optic flow in the visual field: expansion flow, such as that induced by forward motion in depth, or planar motion, such as induced by translational self-motion or by pursuit eye movements across a visual scene. In real life, both signals may occur in combination, yet, only one of the cues may be of behavioral relevance, thus requiring to be selectively attended to. In this fMRI study we attempt to address the question whether differential neural substrates get modulated by selective attention to either one of these motion cues. We created a stimulus combining an expansion flow pattern with translational motion on the same set of dots. In a feature-based detection task, subjects selectively attended either to the expansion or to the translation component of the stimulus and reported changes in the speed of the attended motion component. In control conditions that used the same stimuli subjects attended to color hue changes of the fixation cross, or passively fixated the stimulus without any attentional demand. In each of the three attention conditions, the attentional load was kept constant across conditions by a continuously updating staircase procedure. We found that attention to expansion modulated the separately localized areas MT/V5, MST, and V3A significantly more than attention to translation. This is in line with stimulus-driven studies that showed a preference to expansion/contraction stimuli in these areas (Smith et al., 2006). In contrast, V7 and the cingulate sulcus visual area (CSv) differed from all other regions, in that they did not show any selective modulation by attention to expansion flow. Most interestingly, we found motion selective modulation in the foveal confluence of V1, despite a physical match between stimulus conditions. This might be due to differential attentional enhancement within V1, or by differential feedback from higher regions such as MT/V5, MST or V3A. Our results therefore show a differential attentional modulation within the motion-processing pathway, depending on the type of motion-component that is attended to within the same flow stimulus. Smith AT, Wall MB, Williams AL, Singh KD (2006) Sensitivity to optic flow in human cortical areas MT and MST. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=3b1b2e24-3671-4e3d-9051-5dfbb3c15f6c&cKey=81bf6c91-1c74-4f55-870b-c12dbcb94af7 Biologische Kybernetik Max-Planck-Gesellschaft Chicago, IL, USA 39th Annual Meeting of the Society for Neuroscience (Neuroscience 2009) en efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels poster 5293 2008 11 38 461.19 For the successful estimation of self-motion based on visual cues it is necessary to take self-induced motion signals into account, such as those induced by eye-movements. In this fMRI study we used stimulus conditions that allowed us to differentiate neural responses to (a) retinal motion, (b) eye-movements (visual pursuit) and (c) objective motion. Responses to these three motion cues were measured in context of two types of visual stimuli, namely moving 2D dot-sheets and 3D-expanding flow fields. An additional localizer experiment segregated responses to contra- and ipsi-lateral stimulation as well as to full field coherent expansion as opposed to trajectory matched scrambled random motion. We found that MT/V5 and MST responded primarily to retinal motion and to eye-movements. More parietal regions such as V7 and IPS (intra-parietal sulcus) and a region recently implicated in self-motion processing, the cingulate sulcus visual area (CSv), seem to be driven by all three motion cues. The localizer experiment revealed that all of these regions responded almost exclusively to coherent motion types, while MT+/V5+ also responded, but less strongly, to the matched random motion display. CSv differed from all other regions in that it favored 2D translational coherent motion over 3D expanding flow fields, and in that its responses to ipsi- and contralateral flow were indistinguishable. It thus appears to be a strong candidate for integrating translational motion signals of retinal and non-retinal origin. Area V3A/B differed from most other motion processing regions in that it was primarily affected by objective motion, and also, but less, by visual pursuit. Furthermore, in the localizer it responded equally to coherent 3D flow and to the random motion stimulus. This suggests that V3A/B processes differential rather than coherent or self-induced motion. Our results lead us to suggest that there is a clear functional segregation among higher level motion processing regions in context of self-motion processing cues. It remains to be resolved to which extent the distinct regions inter-operate in a hierarchical or rather in a parallel fashion. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.sfn.org/am2008/ Biologische Kybernetik Max-Planck-Gesellschaft Washington, DC, USA 38th Annual Meeting of the Society for Neuroscience (Neuroscience 2008) efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels poster FischerBLB2008 2008 10 9 5 For the successful estimation of self-motion based on visual cues it is necessary to take self-induced motion signals into account, such as those induced by eye-movements. In this fMRI study we used stimulus conditions that allowed us to differentiate neural responses to (a) retinal motion, (b) eye-movements (visual pursuit) and (c) objective motion. Responses to these three motion cues were measured in context of two types of visual stimuli, namely moving 2D dot-sheets and 3D-expanding ow fields. An additional localizer experiment segregated responses to contra- and ipsi-lateral stimulation as well as to full field coherent expansion as opposed to trajectory matched scrambled random motion. We found that MT/V5 and MST responded primarily to retinal motion and to eye-movements. More parietal regions such as V7 and IPS (intra-parietal sulcus) and a region recently implicated in self-motion processing, the cingulate sulcus visual area (CSv), seem to be driven by all three motion cues. The localizer experiment revealed that all of these regions responded almost exclusively to coherent motion types, while MT+/V5+ also responded, but less strongly, to the matched random motion display. CSv differed from all other regions in that it favored 2D translational coherent motion over 3D expanding ow fields. Also, its responses to ipsi and contralateral ow were indistinguishable. It thus appears to be a strong candidate for integrating translational motion signals of retinal and non-retinal origin. Area V3A/B differed from most other motion processing regions in that it was primarily affected by objective motion, and also, but less, by visual pursuit. Furthermore, in the localizer it responded equally to coherent 3D now and to the random motion stimulus. This suggests that V3A/B processes differential rather than coherent or self-induced motion. Our results lead us to suggest that there is a clear functional segregation among higher level motion processing regions in context of self-motion processing cues. It remains to be resolved to which extent the distinct regions inter-operate in a hierarchical or rather in a parallel fashion. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Bülthoff Department Logothetis http://www.neuroschool-tuebingen-nena.de/index.php?id=284 Ellwangen, Germany 9th Conference of the Junior Neuroscientists of Tübingen (NeNa 2008) efischerEFischer hhbHHBülthoff nikosNKLogothetis abartelsABartels poster 4888 2007 7 10 133 Color is a salient feature which conveys important information about the objects in our visual world and may help identification and recognition. Previous psychophysical experiments in humans suggest that color can be beneficial in visual memory tasks, when shape information is no longer available. Here, we ask whether color in natural scenes improves object recognition under conditions in which shape information is degraded. We used a procedure based on Fourier analysis to create natural scenes, for which we manipulated color and shape information independently. Psychophysical performance of human observers was measured in a delayed matching to sample paradigm. Our observers were presented with natural scenes that contained object related (color image), irrelevant (colored noise) or no color (achromatic image and noise) for which we parametrically varied shape information by introducing noise into the images. Subjects performed significantly better when images contained object related color than no or irrele vant color information across the different noise levels (N = 8, p<0.05). In addition, performance across subjects did not differ for the achromatic stimuli and the images including unrelated color. Our results suggest that recognition of natural scenes can be enhanced by color information that is related to the object. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis http://www.twk.tuebingen.mpg.de/twk07/abstract.php?_load_id=elvira01 Biologische Kybernetik Max-Planck-Gesellschaft Tübingen, Germany 10th Tübinger Wahrnehmungskonferenz (TWK 2007) en efischerEFischer sliebeSLiebe nikosNKLogothetis gregorGRainer