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  • 1
    Electronic Resource
    Electronic Resource
    Visual orientation in the rat: A dissociation of deficits following cortical and collicular lesions (1978)
    Springer
    Experimental brain research 31 (1978), S. 445-457 
    Details
    ISSN: 1432-1106
    Keywords: Superior colliculus ; Visual cortex ; Visually-guided locomotion ; Orienting reflex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats with either bilateral ablations of superior colliculus, bilateral ablations of visual cortex, or sham operations were trained to run across a large arena towards a small illuminated target which varied in location from trial to trial. An impairment in this visually-guided running was apparent in the cortical group, but not in the collicular group. When, in a second experiment, the spatial relationships within the apparatus were changed by extending the entry-tunnel some distance into the arena, the running of the cortical group became even more impaired, while the collicular animals continued to run towards the targets under efficient visual control. In a third experiment, the effect of introducing a novel flashing light in various locations around the perimeter of the arena was investigated. It was found that unlike the other two groups, the collicular animals showed no orienting reflex to the novel stimulus when it was presented outside a broad central area of the visual field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237301
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  • 2
    Electronic Resource
    Electronic Resource
    Visual orientation and detection following lesions of the superior colliculus in rats (1984)
    Springer
    Experimental brain research 56 (1984), S. 106-114 
    Details
    ISSN: 1432-1106
    Keywords: Vision ; Distractibility ; Rats ; Orienting ; Superior colliculus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats with bilateral lesions of the superior colliculus (SC) or with sham operations were trained on a modified version of the running task of Goodale and Murison (1975). The rats were required to shuttle between two large boxes, one of which required a choice between 5 doors, the other having only 1 door. A flashing distractor light at the side of a box was subsequently presented on once-daily test trials. For half the rats of each group these tests were given at 1 month and for the others at 3 months post-operatively. In agreement with previous studies, the SC-lesioned rats showed an abolition of orienting reactions to the distractor. (This was so in both boxes, i.e. a lower attentional load in the running task failed to alleviate the SC lesion-induced deficit.) However, only in the early-tested rats did the lesion cause a loss of freezing response to the distractor. Since in the late-tested group the rats froze but did not orient, it is suggested that the orienting loss at least in their case cannot be attributed to a partial visual field defect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237446
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  • 3
    Electronic Resource
    Electronic Resource
    The perception and prehension of objects oriented in the depth plane (1996)
    Springer
    Experimental brain research 112 (1996), S. 442-451 
    Details
    ISSN: 1432-1106
    Keywords: Visual agnosia ; Visuomotor control ; Orientation ; Depth ; Binocular vision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous studies have reported that the visual form agnosic D.F. is able to use information about visual targets for the control of motor acts, but has great difficulty in using the same visual information for perceptual report. This intact visuomotor performance may be mediated by relatively intact parieto-frontal cortical mechanisms. The present study investigated the ability of D.F. to use binocular and monocular information about the orientation of an object in the depth plane for perceptual and visuomotor purposes. A square plaque was presented at seven different orientations in depth to D.F. and to three age- and sex-matched control subjects. Subjects were required to reach out and grasp the plaque using a precision grip (index finger and thumb) under binocular and monocular viewing conditions, and in separate trials to match the orientation of a hand-held plaque to the perceived orientation of the target object, also under both binocular and monocular conditions. D.F.'s performance in grasping trials was found to be normal under binocular conditions, but was substantially worsened by removal of binocular vision. She was severely impaired at matching the orientation of the test square, although under binocular conditions her performance rose clearly above chance. The data suggest that the separation of cortical processing for visuomotor and visual perceptual purposes also applies, at least in part, to information about the orientation in depth of an object. The impaired performance under monocular viewing conditions on the visuomotor task is in agreement with recent physiological data and suggests that posterior parietal systems depend critically on binocular input for the processing of orientation in depth when ventral-stream information is unavailable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227950
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  • 4
    Electronic Resource
    Electronic Resource
    Nasotemporal overlap in the human retina investigated by means of simple reaction time to lateralized light flash (1983)
    Springer
    Experimental brain research 50 (1983), S. 166-172 
    Details
    ISSN: 1432-1106
    Keywords: Man ; Retina ; Nasotemporal overlap ; Dual representation ; Simple reaction time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary When light flashes are presented laterally simple vocal and manual responses are faster to stimuli in the visual half-field having direct access to the responding hemisphere (an “uncrossed” reaction) than stimuli which go initially to the nonresponding hemisphere (a “crossed” reaction). In the latter case an interhemispheric crossing is presumably necessary and so the crossed-minus-uncrossed difference (CUD) can be identified with interhemispheric transmission time. This paradigm was used to investigate the problem of whether or not there is an overlap of ipsi- and contralaterally projecting ganglion cells at the border between nasal and temporal areas of the human retina, resulting in dual representation of the midline in the brain. If such an overlap does exist then presenting stimuli on this region ought to result in an abolition of the CUD since information would be equally available to both hemispheres. Accordingly vocal and manual reaction times to flashes presented at 1/2, 1, 2, and 4 deg of visual angle were measured. In both cases a consistent CUD was found and this was present at all four points. These results are interpreted as arguing against the existence of overlap in man though some alternative possibilities are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239180
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  • 5
    Electronic Resource
    Electronic Resource
    The effect of stimulus intensity on visual evoked potential estimates of interhemispheric transmission time (1984)
    Springer
    Experimental brain research 57 (1984), S. 89-98 
    Details
    ISSN: 1432-1106
    Keywords: Visual evoked potentials ; Man ; Interhemispheric transmission time ; Intensity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Visual evoked potentials (VEPs) to bright or dim lateralised light flashes were recorded from homologous occipital and central sites. In a GO/NOGO reaction time task (Experiment 1) the latency of the N160 component of the VEP was found to be shorter from the contralateral hemisphere by approximately 16 ms at occipital sites, but only 3 ms centrally. In addition, there was a trend for the occipital contralateral latency advantage to increase with decreasing stimulus brightness. In Experiment 2 a wider intensity range and a simple visual reaction time task were employed. Contralateral N160 latency advantages were again found to be larger occipitally (approx 13 ms) than centrally (3 ms). Furthermore the occipital contralateral latency advantage was significantly increased at the lower stimulus intensity, while that from central sites remained constant. These data suggest that two types of interhemispheric relay can be distinguished — a sensory one recorded occipitally and a non-sensory one recorded from central sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231135
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  • 6
    Electronic Resource
    Electronic Resource
    Visual size processing in spatial neglect (1998)
    Springer
    Experimental brain research 123 (1998), S. 192-200 
    Details
    ISSN: 1432-1106
    Keywords: Key words Neglect ; Spatial perception ; Visumotor tasks ; Visual extent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Evidence from the use of the landmark task and from two size-matching tasks shows that many patients with left-sided neglect systematically under-perceive visual extent in leftward parts of space. This perceptual distortion of size serves to explain the occurrence of rightward line-bisection errors in most neglect patients. One possibility is that attentional biases of a chronic nature might underlie these perceptual changes seen in neglect patients. But contrary to this idea, we have found that attentional cueing in the landmark task causes changes in neglect patients exactly opposite to those seen in healthy subjects. The distortions of size perception seen in neglect could instead be caused by a high-level alteration of visual processing rather than by an attentional bias. In order to explore which visual stream of cortical processing might be compromised in such a disorder, we have begun to examine neglect patients on visuomotor as well as perceptual tasks. We have found clear evidence in one patient for intact grip scaling for object size in the neglected half of space, despite gross perceptual underestimations of the same objects. This result suggests that neglect can occur without major disruption of the dorsal stream, and may result instead from damage to a cortical system whose predominant visual input comes from the ventral stream.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050561
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  • 7
    Electronic Resource
    Electronic Resource
    Inaccourate calculation of drug output from nebulisers (1989)
    Springer
    European journal of pediatrics 148 (1989), S. 473-474 
    Details
    ISSN: 1432-1076
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A multistage liquid impinger was used to collect the nebulised cloud from three separate nebulisers. The output of sodium cromoglycate collected was determined by a spectrophotometric assay. Estimating drug output purely from weight loss during nebulisation resulted in a considerable overestimate compared with direct assay of the drug output from the nebulised cloud. During nebulisation, weight loss from the nebuliser occurs in the form of particle formation and also by evaporation. By only weighing the nebuliser chamber before and after nebulisation, weight loss due to evaporation is not taken into account and this is the cause of the overestimation of drug output by this method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00595919
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    Paper (German National Licenses)
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  • 8
    Electronic Resource
    Electronic Resource
    The effect of changes in inspiratory time on neonatal triggered ventilation (1990)
    Springer
    European journal of pediatrics 149 (1990), S. 648-650 
    Details
    ISSN: 1432-1076
    Keywords: Triggered ventilation ; Inspiratory time ; Neonates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nine preterm infants with hyaline membrane disease were studied using a ventilator triggered from abdominal movement. It was possible to alter respiratory rate over a short space of time by adjustments of the inspiratory time setting. There was a marked inverse relationship between inspiratory time and both ventilator and baby's respiratory rate-mean baby respiratory rate was 62 breaths/min at an inspiratory time of 0.2 s and 45 breaths/min at 0.8 s. This drop was statistically significant (P〈0.005). Mean tidal volume changed little over this range. This interaction meant that mean minute ventilation was optimal at inspiratory times of 0.2 to 0.4 s, being 269 and 258 ml/kg per minute, respectively, but at 0.8 s fell to 213 ml/kg per minute (P〈0.05).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02034755
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    The respiratory syncitial virus and its role in acute bronchiolitis (1992)
    Springer
    European journal of pediatrics 151 (1992), S. 638-651 
    Details
    ISSN: 1432-1076
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01957564
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  • 10
    Electronic Resource
    Electronic Resource
    The effects of mid-trimester amniocentesis on lung function in the neonatal period (1992)
    Springer
    European journal of pediatrics 151 (1992), S. 458-460 
    Details
    ISSN: 1432-1076
    Keywords: Neonate ; Lung function ; Amniocentesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Lung function tests were carried out on 39 healthy full term babies born after pregnancies subjected to mid-trimester amniocentesis. The results were compared to 42 babies born after normal pregnancies. There were no significant differences in gestational age, birth weight, thoracic gas volume or crying vital capacity. Babies subjected to amniocentesis had a significantly lower dynamic compliance (6.96ml/cm H2O vs. 8.60ml/cm H2O) and tended to have higher resistence compared to controls (52.8 cm H2O/l/s vs. 37.3 cm H2O/l/s). This provides further evidence that mid-trimester amniocentesis does have an adverse effect on lung growth and development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01959364
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