共查询到20条相似文献，搜索用时 15 毫秒
1.
Despite extensive evidence for regions of human visual cortex that respond selectively to faces, few studies have considered the cortical representation of the appearance of the rest of the human body. We present a series of functional magnetic resonance imaging (fMRI) studies revealing substantial evidence for a distinct cortical region in humans that responds selectively to images of the human body, as compared with a wide range of control stimuli. This region was found in the lateral occipitotemporal cortex in all subjects tested and apparently reflects a specialized neural system for the visual perception of the human body. 相似文献
2.
Primates can recognize faces across a range of viewing conditions. Representations of individual identity should thus exist that are invariant to accidental image transformations like view direction. We targeted the recently discovered face-processing network of the macaque monkey that consists of six interconnected face-selective regions and recorded from the two middle patches (ML, middle lateral, and MF, middle fundus) and two anterior patches (AL, anterior lateral, and AM, anterior medial). We found that the anatomical position of a face patch was associated with a unique functional identity: Face patches differed qualitatively in how they represented identity across head orientations. Neurons in ML and MF were view-specific; neurons in AL were tuned to identity mirror-symmetrically across views, thus achieving partial view invariance; and neurons in AM, the most anterior face patch, achieved almost full view invariance. 相似文献
3.
Mukamel R Gelbard H Arieli A Hasson U Fried I Malach R 《Science (New York, N.Y.)》2005,309(5736):951-954
Functional magnetic resonance imaging (fMRI) is an important tool for investigating human brain function, but the relationship between the hemodynamically based fMRI signals in the human brain and the underlying neuronal activity is unclear. We recorded single unit activity and local field potentials in auditory cortex of two neurosurgical patients and compared them with the fMRI signals of 11 healthy subjects during presentation of an identical movie segment. The predicted fMRI signals derived from single units and the measured fMRI signals from auditory cortex showed a highly significant correlation (r = 0.75, P < 10(-47)). Thus, fMRI signals can provide a reliable measure of the firing rate of human cortical neurons. 相似文献
4.
The functional organization of the second cortical visual area was examined with three different anatomical markers: 2-[14C]deoxy-D-glucose, cytochrome oxidase, and various myelin stains. All three markers revealed strips running throughout the area, parallel to the cortical surface. The boundaries of these strips provide an anatomical criterion for defining the borders of this extrastriate region. Further, the demonstration of these strips allows a functional and anatomical analysis of modules in the area, just as the recent demonstration of spots in the primary visual cortex has allowed an analysis of modules there. The strips differ structurally and functionally from interstrip regions and these differences are similar to those seen between the spots and the interspot regions in the primary visual cortex. In the macaque the strips and spots differ with regard to binocular organization. 相似文献
5.
In crowded visual scenes, attention is needed to select relevant stimuli. To study the underlying mechanisms, we recorded neurons in cortical area V4 while macaque monkeys attended to behaviorally relevant stimuli and ignored distracters. Neurons activated by the attended stimulus showed increased gamma-frequency (35 to 90 hertz) synchronization but reduced low-frequency (<17 hertz) synchronization compared with neurons at nearby V4 sites activated by distracters. Because postsynaptic integration times are short, these localized changes in synchronization may serve to amplify behaviorally relevant signals in the cortex. 相似文献
6.
Physiological evidence for serial processing in somatosensory cortex 总被引：10，自引：0，他引：10
Removal of the representation of a specific body part in the postcentral cortex of the macaque resulted in the somatic deactivation of the corresponding body part in the second somatosensory area. In contrast, removal of the entire second somatosensory area had no grossly detectable effect on the somatic responsivity of neurons in the postcentral cortex. This direct electrophysiological evidence for serial cortical processing in somesthesia is similar to that found earlier for vision and, taken together with recent anatomical evidence, suggests that there is a common cortical plan for the processing of sensory information in the various sensory modalities. 相似文献
7.
Complex biological systems such as human language and the genetic code are characterized by explicit markers at the beginning and end of functional sequences. We report here that macaque prefrontal cortical neurons exhibit phasic peaks of spike activity that occur at the beginning and endpoint of sequential oculomotor saccade performance and have the properties of dynamic start- and end-state encoders accompanying responses to sequential actions. Sequence bounding may thus reflect a general mechanism for encoding biological information. 相似文献
8.
The brain processes objects through a series of regions along the ventral visual pathway, but the circuitry subserving the analysis of specific complex forms remains unknown. One complex form category, faces, selectively activates six patches of cortex in the macaque ventral pathway. To identify the connectivity of these face patches, we used electrical microstimulation combined with simultaneous functional magnetic resonance imaging. Stimulation of each of four targeted face patches produced strong activation, specifically within a subset of the other face patches. Stimulation outside the face patches produced an activation pattern that spared the face patches. These results suggest that the face patches form a strongly and specifically interconnected hierarchical network. 相似文献
9.
Nishimura Y Onoe H Morichika Y Perfiliev S Tsukada H Isa T 《Science (New York, N.Y.)》2007,318(5853):1150-1155
Transection of the direct cortico-motoneuronal pathway at the mid-cervical segment of the spinal cord in the macaque monkey results in a transient impairment of finger movements. Finger dexterity recovers within a few months. Combined brain imaging and reversible pharmacological inactivation of motor cortical regions suggest that the recovery involves the bilateral primary motor cortex during the early recovery stage and more extensive regions of the contralesional primary motor cortex and bilateral premotor cortex during the late recovery stage. These changes in the activation pattern of frontal motor-related areas represent an adaptive strategy for functional compensation after spinal cord injury. 相似文献
10.
Humans and animals confuse lateral mirror images, such as the letters "b" and "d," more often than vertical mirror images, such as the letters "b" and "p." Experiments were performed to find a neural correlate of this phenomenon. Visually responsive pattern-selective neurons in the inferotemporal cortex of macaque monkeys responded more similarly to members of a lateral mirror-image pair than to members of a vertical mirror-image pair. The phenomenon developed within 20 milliseconds of the onset of the visual response and persisted to its end. It occurred during presentation of stimuli both at the fovea and in the periphery. 相似文献
11.
Ventura M Antonacci F Cardone MF Stanyon R D'Addabbo P Cellamare A Sprague LJ Eichler EE Archidiacono N Rocchi M 《Science (New York, N.Y.)》2007,316(5822):243-246
A systematic fluorescence in situ hybridization comparison of macaque and human synteny organization disclosed five additional macaque evolutionary new centromeres (ENCs) for a total of nine ENCs. To understand the dynamics of ENC formation and progression, we compared the ENC of macaque chromosome 4 with the human orthologous region, at 6q24.3, that conserves the ancestral genomic organization. A 250-kilobase segment was extensively duplicated around the macaque centromere. These duplications were strictly intrachromosomal. Our results suggest that novel centromeres may trigger only local duplication activity and that the absence of genes in the seeding region may have been important in ENC maintenance and progression. 相似文献
12.
Gazzaniga MS 《Science (New York, N.Y.)》2000,289(5486):1887-1888
Although there are elegants maps of the human brain that reveal differences in cellular architecture between different cortical regions, there is not much information about how corresponding cortical regions differ between the left and right hemispheres. As Gazzaniga explains in his Perspective, new results reveal the surprising finding of asymmetry in area 22 (which is important for language processing) of the left and right hemisphere (Galuske et al.). Clusters of neurons in area 22 of the left hemisphere are spaced farther apart and have longer axons cabling them together than neuronal clusters in area 22 of the right hemisphere. 相似文献
13.
Neuronal correlates of subjective visual perception 总被引：10，自引：0，他引：10
Neuronal activity in the superior temporal sulcus of monkeys, a cortical region that plays an important role in analyzing visual motion, was related to the subjective perception of movement during a visual task. Single neurons were recorded while monkeys (Macaca mulatta) discriminated the direction of motion of stimuli that could be seen moving in either of two directions during binocular rivalry. The activity of many neurons was dictated by the retinal stimulus. Other neurons, however, reflected the monkeys' reported perception of motion direction, indicating that these neurons in the superior temporal sulcus may mediate the perceptual experience of a moving object. 相似文献
14.
目的 初步阐明高血压前期红外热成像特征,为高血压前期早期诊疗提供可视化依据。方法 随机选取岳阳市中医院治未病中心2015年3-6月体检的150例受检者,分为高血压前期组、高血压病组及健康志愿者组共3组,每组50例,采集各组研究对象头面部、心前区、背部红外热成像图像,并进行定性与定量分析。结果 高血压前期受检者头面部可见深红色图像,心前区见红黄夹杂图像;高血压组头面部可见深红色与白色夹杂图像,心前区可见红色不连续图像;高血压前期与高血压病组背部出现背带裤样偏红图像。定量研究结果显示,高血压前期受检者头面部平均温度显著低于高血压病组（P=0.004）,高于健康志愿者组（P=0.017）;心前区平均温度显著低于高血压病组（P<0.001）,高于健康志愿者组（P=0.010）。结论 高血压前期人群在头面部、心前区以及背部有其特定的红外热图,为高血压前期的早期诊疗提供可视化依据。 相似文献
15.
DeFalco J Tomishima M Liu H Zhao C Cai X Marth JD Enquist L Friedman JM 《Science (New York, N.Y.)》2001,291(5513):2608-2613
We report the development of a pseudorabies virus that can be used for retrograde tracing from selected neurons. This virus encodes a green fluorescent protein marker and replicates only in neurons that express the Cre recombinase and in neurons in synaptic contact with the originally infected cells. The virus was injected into the arcuate nucleus of mice that express Cre only in those neurons that express neuropeptide Y or the leptin receptor. Sectioning of the brains revealed that these neurons receive inputs from neurons in other regions of the hypothalamus, as well as the amygdala, cortex, and other brain regions. These data suggest that higher cortical centers modulate leptin signaling in the hypothalamus. This method of neural tracing may prove useful in studies of other complex neural circuits. 相似文献
16.
Experience can alter synaptic connectivity throughout life, but the degree of plasticity present at each age is regulated by mechanisms that remain largely unknown. Here, we demonstrate that Paired-immunoglobulin-like receptor B (PirB), a major histocompatibility complex class I (MHCI) receptor, is expressed in subsets of neurons throughout the brain. Neuronal PirB protein is associated with synapses and forms complexes with the phosphatases Shp-1 and Shp-2. Soluble PirB fusion protein binds to cortical neurons in an MHCI-dependent manner. In mutant mice lacking functional PirB, cortical ocular-dominance plasticity is more robust at all ages. Thus, an MHCI receptor is expressed in central nervous system neurons and functions to limit the extent of experience-dependent plasticity in the visual cortex throughout life. PirB is also expressed in many other regions of the central nervous system, suggesting that it may function broadly to stabilize neural circuits. 相似文献
17.
Cortical flow in animal cells 总被引：54，自引：0，他引：54
A concerted flow of actin filaments associated with the inner face of the plasma membrane may provide the basis for many animal cell movements. The flow is driven by gradients of tension in the cell cortex, which pull cortical components from regions of relaxation to regions of contraction. In some cases cortical components return through the cytoplasm to establish a continuous cycle. This cortically located motor may drive cell locomotion, growth cone migration, the capping of antigens on a lymphocyte surface, and cytokinesis. 相似文献
18.
Choline excites cortical neurons 总被引：6，自引：0，他引：6
In cats under halothane or methoxyflurane, iontophoretic applications of choline are only eight times weaker than applications of acetylcholine in evoking firing of neurons in the sensorimotor region of the cerebral cortex. The action of choline is suppressed by atropine but not by two agents that block choline uptake (hemicholinium-3 and triethylcholine), and is not potentiated by an anticholinesterase (physostigmine). Choline therefore appears to excite cortical neurons by a direct action, which may be a significant component of its beneficial therapeutic effects. 相似文献
19.
The cerebral cortex of the human brain is a sheet of about 10 billion neurons divided into discrete subdivisions or areas that process particular aspects of sensation, movement, and cognition. Recent evidence has begun to transform our understanding of how cortical areas form, make specific connections with other brain regions, develop unique processing networks, and adapt to changes in inputs. 相似文献
20.
Localization of amyloid beta protein messenger RNA in brains from patients with Alzheimer's disease 总被引：43，自引：0，他引：43
S Bahmanyar G A Higgins D Goldgaber D A Lewis J H Morrison M C Wilson S K Shankar D C Gajdusek 《Science (New York, N.Y.)》1987,237(4810):77-80
The distribution of cells containing messenger RNA that encodes amyloid beta protein was determined in hippocampi and in various cortical regions from cynomolgus monkeys, normal humans, and patients with Alzheimer's disease by in situ hybridization. Both 35S-labeled RNA antisense and sense probes to amyloid beta protein messenger RNA were used to ensure specific hybridization. Messenger RNA for amyloid beta protein was expressed in a subset of neurons in the prefrontal cortex from monkeys, normal humans, and patients with Alzheimer's disease. This messenger RNA was also present in the neurons of all the hippocampal fields from monkeys, normal humans and, although to a lesser extent in cornu ammonis 1, patients with Alzheimer's disease. The distribution of amyloid beta protein messenger RNA was similar to that of the neurofibrillary tangles of Alzheimer's disease in some regions, but the messenger RNA was also expressed in other neurons that are not usually involved in the pathology of Alzheimer's disease. 相似文献