摘要:

Bushbabies were trained on a battery of visual discrimination and localization tests and retested after serial lesions of the occipital and temporal lobes. The results of these experiments indicated that visual deficits following occipital lobectomy depend on the extent of damage to the central vision representation in both striate and peristriate cortices. If lesions involved both cortical representations of central vision, form and stripes discrimination capacities were lost. When the peristriate representation was spared, form vision was lost but vision for striped patterns was retained. The subsequent addition of middle or ventral temporal area lesions did not alter discrimination performance. Results are discussed in terms of a transcytoarchitectonic subdivision in striate and peristriate cortices as the functional unit of organization for pattern vision.

ISSN:0006-8977    

DOI:10.1159/000121624

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Recordings from the basal optic neuropil (BON) demonstrated directional sensitivity. These directional sensitivities were different in different units, however, most of them displayed a strong vertical component. Inhibition in the non-preferred direction did not occur, only a lower activation than in the preferred direction was found. The identified velocity functions correlate well with the velocity dependence of the nystagmus frequency demonstrated in the behavior. The units responded well to moving large-area stimuli and exhibited horizontally elongated receptive fields with diameters up to 120°. Additionally, bimodal recordings were observed in the BON which were probably due to input from the otoliths. As the recordings are likely to be presynaptic, the BON receives types of input which establish its function in the control of visuomotor behavior

ISSN:0006-8977    

DOI:10.1159/000121625

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A conservative eutherian mammal (the hedgehog, Paraechinus hypomelas) was tested on delayed alternation performance and spatial reversal learning before and after ablations of the prefrontal cortex. The anatomical results show that the cortical focus of the projections of the medial dorsal nucleus, the prefrontal cortex, does not include the neocortex on the dorsal convexity of the hedgehog''s frontal lobe but, instead, the perirhinal and pregenual neocortex immediately surrounding the frontal convexity. The behavioral results show that normal performance of hedgehogs on these two behavioral tests depends upon the integrity of their prefrontal cortex, but not on the integrity of their frontal convexity or olfactory bulbs. The similarity in the results obtained from prefrontal hedgehogs and a divergent variety of other species with prefrontal ablations indicates that the role of the prefrontal system in the abilities measured by these two tests is at least as old as Eutheria and, thus, probably imposed persistent constraints on subsequent evolutionary modifications of the prefrontal system.

ISSN:0006-8977    

DOI:10.1159/000121626

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121627

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121628

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121629

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121630

出版商:S. Karger AG    

年代:1982

数据来源: Karger