Human neurobiology最新文献_第2页

Importance of the visual and vestibular cortex for self-motion perception in man (circularvection). 视觉和前庭皮层对人类自我运动知觉的重要性(循环)。

Human neurobiology Pub Date : 1987-01-01

A Straube, T Brandt

{"title":"Importance of the visual and vestibular cortex for self-motion perception in man (circularvection).","authors":"A Straube, T Brandt","doi":"","DOIUrl":"","url":null,"abstract":"Circularvection (CV), the optokinetically induced perception of self-motion, is based neurophysiologically upon visual-vestibular convergence. It is yet not known which visual pathways--subcortical accessory optic tract and/or cortical striate projection--convey optokinetic information to the central vestibular system in order to make possible the convergence that has been found: the vestibular nuclei, the thalamus and the vestibular cortex. The functional significance of the visual cortex was demonstrated in 12 patients with homonymous hemianopia who neither perceived CV nor exhibited a postural destabilization when exposed to optokinetic pattern motion (yaw or roll) restricted to the scotoma. The functional significance of the vestibular cortex as well as ipsilateral visual-vestibular interaction was demonstrated in 4 (out of 20) patients with tumour lesions involving the vestibular cortex areas. They either failed to perceive CV or showed a significant increase of CV-latencies when monocular optokinetic stimulation was restricted to the ipsilateral visual cortex. Arguments for and against the following hypothesis are discussed: circularvection is induced by visual motion stimulation of the primary visual cortex which then activates vestibular nuclei neurons by descending pathways and which also informs the vestibular cortex that self-motion with a perceptual direction is involved. Determination of the velocity of CV is mediated by direct visual-vestibular cortex interaction, which most probably is also involved in the perceptual interpretation of motion perception: Self-motion versus object-motion.","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"6 3","pages":"211-8"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14574030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dream bizarreness and the activation-synthesis hypothesis. 梦的奇异性与激活-合成假说。

Human neurobiology Pub Date : 1987-01-01

J A Hobson, S A Hoffman, R Helfand, D Kostner

引用次数: 0

The reliability of estimates of interhemispheric transmission times derived from unimanual and verbal response latencies. 从单手和言语反应潜伏期得出的半球间传递时间估计的可靠性。

Human neurobiology Pub Date : 1987-01-01

R St John, C Shields, P Krahn, B Timney

{"title":"The reliability of estimates of interhemispheric transmission times derived from unimanual and verbal response latencies.","authors":"R St John, C Shields, P Krahn, B Timney","doi":"","DOIUrl":"","url":null,"abstract":"In this study, the reliability of estimates of interhemispheric transmission times derived from verbal and unimanual responses was assessed. Responses were made to presentations of lateralized light flashes in a series of 20 experimental sessions, with responses being made to stimuli presented at three different retinal eccentricities. The reliability of estimates of interhemispheric transmission across 20 experimental sessions was generally poorer for verbal compared to unimanual responses. This was particularly true for stimuli presented close to the centre of the visual field. In addition, for unimanual response conditions, estimates of interhemispheric transmission times for the female subjects were longer in duration and exhibited poorer reliability than estimates found for the male subjects. In the verbal response conditions, there were no differences between the mean durations of the estimates found for the male and female subjects. The results suggest that for centrally located stimulus presentations, verbal responses do not produce reliable estimates of interhemispheric transmission time. This relatively poor reliability across experimental sessions may account for the mixed results seen in previous studies which have used verbal reaction times to estimate interhemispheric transmission time. The collection of unimanual responses to lateralized visual stimulus presentations is likely the best method of estimating interhemispheric transmission time in normal man.","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"6 3","pages":"195-202"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13973049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Focal and diffuse memory activation assessed by localized indicators of CNS metabolism: the semantic-episodic memory distinction. 中枢神经系统代谢的局部指标评估局灶性和弥漫性记忆激活:语义-情景记忆的区别。

Human neurobiology Pub Date : 1987-01-01

F Wood

引用次数: 0

Selective hemispheric stimulation by unilateral forced nostril breathing. 单侧强迫鼻孔呼吸的选择性半球刺激。

Human neurobiology Pub Date : 1987-01-01

D A Werntz, R G Bickford, D Shannahoff-Khalsa

引用次数: 0

The interaction between EEG and transient muscle activity during sleep in humans. 人类睡眠中脑电图与短暂性肌肉活动的相互作用。

Human neurobiology Pub Date : 1987-01-01

J J Pilcher, H Schulz

引用次数: 0

Cognitive evoked potentials as modulatory processes in human memory formation and retrieval. 认知诱发电位在人类记忆形成和检索中的调节作用。

Human neurobiology Pub Date : 1987-01-01

E Halgren, M E Smith

{"title":"Cognitive evoked potentials as modulatory processes in human memory formation and retrieval.","authors":"E Halgren, M E Smith","doi":"","DOIUrl":"","url":null,"abstract":"The complex experiential nature of human cognitive memories implies that their formation and retrieval result from neural activity that is widespread and patterned. This integration of widespread activity into coherently patterned gestalts is accompanied by event related brain potentials (ERPs). ERP component N4, reflecting associative activation, declines as words or faces become more familiar. ERP component P3, reflecting cognitive closure, generally grows larger with familiarity. Similar changes in the N4/P3 are seen to familiarity in remote semantic memory. The N4/P3 may be generated directly by the multitude of specific neuronal interactions that constitute associative activation and contextual closure. Alternatively, the N4/P3 may be generated by diffuse modulatory pathways exerting non-specific control over these same interactions. In any case, the N4 and P3 appear to be generated simultaneously in several neocortical and subcortical structures, including the medial temporal lobe (MTL), where lesions are known to produce a profound deficit in learning new cognitive material. The MTL in the dominant hemisphere is necessary for the extratemporal N4/P3 generators to alter their response to words that are familiar in context. The mechanism whereby the MTL controls cortical activation is unknown. However, some hippocampal neurons are activated by particular words, suggesting that the MTL contributes specific information to the cortex during memory retrieval. These properties of the N4/P3 bear a close similarity to modulatory processes which have been found to aid formal associative networks in creating patterns that best represent current input in light of past experience. These modulatory processes consist of an initial generalized activation that encourages partially specified widespread elements to emerge as a network, followed by inhibition that focuses the emerging pattern into a coherent gestalt.","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"6 2","pages":"129-39"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14432613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Importance of the visual cortex for postural stabilization: inferences from pigeon and frog data. 视觉皮层对姿势稳定的重要性:来自鸽子和青蛙数据的推论。

Human neurobiology Pub Date : 1987-01-01

A Straube, T Brandt, T Probst

{"title":"Importance of the visual cortex for postural stabilization: inferences from pigeon and frog data.","authors":"A Straube, T Brandt, T Probst","doi":"","DOIUrl":"","url":null,"abstract":"Optokinetically induced self-motion with its consequences for postural balance is based upon visual-vestibular convergence. It is a matter for speculation which visual pathways--subcortical accessory optic tract and/or cortical striate projection--convey optokinetic information to the central vestibular system. The functional significance of the visual cortex was tested by a behavioral approach in two animals, selected for their different evolutionary stage: frog (midbrain visual center); pigeon (primitive neocortical center). Lateral postural sway during optokinetic stimulation in roll served as a measurement for induced rollvection and apparent body tilt. Roll motion elicits a tonic 'compensatory' postural adjustment towards the direction of pattern motion in pigeon as in man but not in frog. From the lack of this reaction we infer that the frog does not perceive rollvection because it has no visual cortex. This agrees with the absence of visual-vestibular convergence in the frogs vestibular nuclei neurons as well as the absence of a nystagmus velocity storage in the brainstem. The animal experiments fit human data in hemianopic patients who also only experience rollvection when stimulated in the unaffected hemifield.","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"6 1","pages":"39-43"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14619532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics of EEG slow wave activity during physiological sleep and after administration of benzodiazepine hypnotics. 生理睡眠和使用苯二氮卓类安眠药后脑电图慢波活动的动态。

Human neurobiology Pub Date : 1987-01-01

P Achermann, A A Borbély

引用次数: 0

Brain mechanisms and memory. 大脑机制和记忆。

Human neurobiology Pub Date : 1987-01-01

M Kinsbourne

{"title":"Brain mechanisms and memory.","authors":"M Kinsbourne","doi":"","DOIUrl":"","url":null,"abstract":"When mental operations share input and output mechanisms, it is necessary to resort to neuropsychological evidence to determine whether they belong to the same or different systems. That multiple memory systems exist is suggested by dissociation between memory performances by normal people, and proven by dissociations in memory performances induced by focal brain damage. The pathological forgetting of the amnesic syndrome is limited to memory for events (\"episodic memory\") and appears to be due to the patient's inability in escape from control of his present internal and external environment in order to recollect (consciously, by reexperience) a prior event. Effects of prior experience on subsequent performance that does not involve conscious recollection (\"semantic memory\") remains intact. The distinction between episodic and semantic memory is an instance of a broader distinction between conscious and unconscious mental operations, in humans and possibly other mammals also. However, the further subdivision of semantic memory into procedural and declarative lacks empirical basis, and indeed seems impossible to operationalize. Amnesics' difficulty in recollecting events (and partially learned facts) from before the onset of their disease (retrograde amnesia) is explicable in terms of interference between current events and prior events in similar contexts in patients who are unduly controlled by their current context. Consolidation theory is incoherent, and not needed to explain retrograde amnesia.","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"6 2","pages":"81-92"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14244855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0