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The role of segmentation in phonological processing: An fMRI investigation

JOURNAL OF COGNITIVE NEUROSCIENCE 2000年第4期12卷 679-690页

作者： Burton, MW Small, SL Blumstein, SE Univ Maryland Sch Med Dept Neurol Baltimore MD 21201 USA Brown Univ Providence RI 02912 USA

Phonological processes map sound information onto higher levels of language processing and provide the mechanisms by which verbal information can be temporarily stored in working memory. Despite a strong convergence of data suggesting both left lateralization and distributed encoding in the anterior and posterior perisylvian language areas, the nature and brain encoding of phonological subprocesses remain ambiguous. The present study used functional magnetic resonance imaging (fMRI) to investigate the conditions under which anterior (lateral frontal) areas are activated during speech-discrimination tasks that differ in segmental processing demands. In two experiments, subjects performed "same/ different" judgments on the first sound of pairs of words. In the first experiment, the speech stimuli did not require overt segmentation of the initial consonant from the rest of the word, since the "different" pairs only varied in the phonetic voicing of the initial consonant (e.g., dip-tip). In the second experiment, the speech stimuli required segmentation since "different" pairs both varied in initial consonant voicing and contained different vowels and final consonants (e.g., dip-ten). These speech conditions were compared to a tone-discrimination control condition. Behavioral data showed that subjects were highly accurate in both experiments, but revealed different patterns of reaction-time latencies between the two experiments. The imaging data indicated that whereas both speech conditions showed superior temporal activation when compared to tone discrimination, only the second experiment showed consistent evidence of frontal activity. Taken together, the results of Experiments 1 and 2 suggest that phonological processing per se does not necessarily recruit frontal areas. We postulate that frontal activation is a produce of segmentation processes in speech perception, or alternatively, working memory demands required for such processing.

关键词：行为/生理学脑图额叶/解剖学和组织学额叶/生理学磁共振成像语音学音调辨别/生理学反应时间/生理学言语识别测验言语知觉/生理学颞叶/解剖学和组织学颞叶/生理学成年人女(雌)性人类男(雄)性

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Introduction: What is where in the medial temporal lobe?

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HIPPOCAMPUS 1999年第1期9卷 1-6页

作者： Amaral, DG Univ Calif Davis Ctr Neurosci Livermore CA 95616 USA

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A new anatomical landmark for reliable identification of human area V5/MT: a quantitative analysis of sulcal patterning

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CEREBRAL CORTEX 2000年第5期10卷 454-463页

作者： Dumoulin, SO Bittar, RG Kabani, NJ Baker, CL Le Goualher, G Pike, GB Evans, AC McGill Univ Montreal Neurol Inst McConnell Brain Imaging Ctr Montreal PQ H3A 2B4 Canada Univ Utrecht Utrecht Netherlands McGill Univ Dept Ophthalmol McGill Vis Res Unit Montreal PQ H3A 2T5 Canada

The location of human area V5 (or MT) has been correlated with the intersection of the ascending limb of the inferior temporal sulcus (ALITS) and the lateral occipital sulcus (LO). This study was undertaken to attempt a replication and quantification of these observations using functional magnetic resonance imaging. V5 was significantly activated in 19 hemispheres with alternating, low contrast, random checkerboard patterns. We confirmed the stereotaxic location of V5 and were able to describe a fairly consistent sulcal pattern in the parieto-temporo-occipital cortex. V5 was usually (95%) buried within a sulcus, most commonly within the inferior temporal sulcus (ITS) (11%), the ascending limb of the ITS (ALITS) (53%) and the posterior continuation of the ITS (26%). The average distance from V5 of two identified anatomical landmarks of V5, the junctions of the LO and the ALITS, and the ITS and ALITS, were both similar to 1 cm. However, the LO-ALITS junction often had to be determined by interpolation (47%), and was not always present even with interpolation (21%). In contrast, the ITS-ALITS junction was always present and V5 was usually (90%) located in a sulcus intersecting with this junction, making it a more reliable landmark for localizing V5 with respect to gross morphological features on individual cortical surfaces.

关键词：解剖学/标准磁共振成像顶叶/解剖学和组织学顶叶/生理学光刺激可重复性结果颞叶/解剖学和组织学颞叶/生理学视皮质/解剖学和组织学视皮质/生理学成年人女(雌)性人类男(雄)性

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COLUMNAR CORTICO-CORTICAL INTERCONNECTIONS WITHIN THE VISUAL-SYSTEM OF THE SQUIRREL AND MACAQUE MONKEYS

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BRAIN RESEARCH 1979年第2期162卷 201-217页

作者： WONGRILEY, M Dept. Anat. Univ. California San Francisco Calif. 94143

Cortico-cortical interconnections within the visual cortex of squirrel monkeys (Saimiri sciureus) were studied by single or multiple injections of [3H]leucine or combined [3H]leucine and horseradish peroxidase into the dorsolateral striate and prestriate cortices. Injections of [3H]leucine were also made into the dorsolateral striate cortex of a Macaca speciosa for comparison. In Saimiri the dorsolateral prestriate cortex is precisely and reciprocally connected with the striate and peristriate cortex, and with the posterior bank of the superior temporal sulcus, including the middle temporal area (MT). The dorsolateral striate area is precisely and reciprocally connected with the prestriate and MT area, but does not project to the perstriate cortex as in the case of the macaque. At each target site, the radioactively labeled terminal fields are distributed in a distinctly columnar fashion, with labeled columns (120-480 .mu.m in diameter, commonly 240 .mu.m) interdigitating with sparsely labeled or unlabeled columns of lesser widths. The HHP-labeled neurons invariably exist within the radioactively labeled columns. For all of the cortical areas examined except area 17, lamina IV is the principal receptive layer for associational fibers, while layers III and II, and V and VI within the same column, receive progressively less input. As for area 17, associational fibers from the prestriate cortex terminate mainly within lamina I, with laminae II, III, V and VI receiving decreasing amounts of input. The major visual cortical areas are interconnected in precise, topographical and reciprocal fashion. The columnar arrangement is the basis of both extra- and intercortical connections.

关键词：放射自显影术脑图半球优势大脑/生理学类人猿亚目猕猴属神经纤维/超微结构松鼠猴属颞叶/解剖学和组织学视皮质/解剖学和组织学视通路/解剖学和组织学动物男(雄)性

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"What" - Then - "where" in visual working memory: An event-related, fMRI study

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JOURNAL OF COGNITIVE NEUROSCIENCE 1999年第6期11卷 585-597页

作者： Postle, BR D'Esposito, M Univ Penn Med Ctr Dept Neurol Philadelphia PA 19104 USA

Behavioral studies indicate that spatial and object working memory are computed by dissociable subsystems. We investigated the neural bases of this dissociation with a whole-brain fMRI design and analysis technique that permitted direct assessment of delay-period activity, uncontaminated by other components of the trial. The task employed a "what"-then-"where" design, with an object and a spatial delay period incorporated in each trial, within-trial order of delay conditions was balanced across each scan. Our experiment failed to find evidence, at the single-subject level and at the group level, for anatomical segregation of spatial and object working memory function in the frontal cortex. Delay-period activity in the caudate nucleus revealed a sensitivity to position in the trial in the spatial, but not the object, condition. In posterior regions, spatial delay-period activity was associated with preferential recruitment of extrastriate areas falling within Brodmann's area 19 and, less reliably, the superior parietal lobule. Object-specific delay-period activity was found predominantly in ventral regions of the posterior cortex and demonstrated more topographic variability across subjects than did spatial working memory activity.

关键词：尾状核/解剖学和组织学尾状核/生理学磁共振成像记忆/生理学枕叶/解剖学和组织学枕叶/病理生理学顶叶/解剖学和组织学顶叶/生理学额叶前皮质/解剖学和组织学额叶前皮质/生理学颞叶/解剖学和组织学颞叶/生理学视知觉/生理学成年人女(雌)性人类男(雄)性

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Functional anatomy of pursuit eye movements in humans as revealed by fMRI

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JOURNAL OF NEUROPHYSIOLOGY 1999年第1期82卷 463-471页

作者： Petit, L Haxby, JV NIMH Lab Brain & Cognit Bethesda MD 20892 USA

We have investigated the functional anatomy of pursuit eye movements in humans with functional magnetic imaging. The performance of pursuit eye movements induced activations in the cortical eye fields also activated during the execution of visually guided saccadic eye movements, namely in the precentral cortex [frontal eye field (FEF)], the medial superior frontal cortex (supplementary eye field), the intraparietal cortex (parietal eye field), and the precuneus, and at the junction of occipital and temporal cortex (MT/MST) cortex. Pursuit-related areas could be distinguished from saccade-related areas both in terms of spatial extent and location. Pursuit-related areas were smaller than their saccade-related counterparts, three of eight significantly so. The pursuit-related FEF was usually inferior to saccade-related FEF. Other pursuit-related areas were consistently posterior to their saccade-related counterparts. The current findings provide the first functional imaging evidence for a distinction between two parallel cortical systems that subserve pursuit and saccadic eye movements in humans.

关键词：脑图/方法大脑皮质/生理学额叶/解剖学和组织学额叶/生理学磁共振成像/方法枕叶/解剖学和组织学枕叶/生理学顶叶/解剖学和组织学顶叶/生理学视跟踪平稳/生理学回归分析眼扫视/生理学颞叶/解剖学和组织学颞叶/生理学成年人女(雌)性人类男(雄)性

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Convergent and complementary projections of the caudal paralaminar thalamic nuclei to rat temporal and insular cortex

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CEREBRAL CORTEX 2000年第8期10卷 753-771页

作者： Linke, R Schwegler, H Otto von Guericke Univ Inst Anat D-39120 Magdeburg Germany

Thalamic nuclei adjacent to the medial geniculate body play a pivotal role in processing of sensory stimuli during emotional situations. These nuclei, which include the suprageniculate nucleus (SG), the posterior intralaminar nucleus (PIN), the peripeduncular nucleus (PP) and the medial division of the medial geniculate body (MGm). project to both cortex and amygdala. but target areas and the extent of the projection of individual nuclei are not known yet. The aim of the present study was to analyze the contribution of individual nuclei to the cortical projection with modern sensitive tracing techniques. Small injections of Miniruby or PHA-L were made into single thalamic nuclei. All thalamic nuclei have in common a projection into the upper portion of layer I of the temporal aspect of the cortical mantle. Furthermore, SG, PIN, MGm and PP each demonstrated a convergent projection to lower layer ill and to layer IV of the ectorhinal and visceral cortex. Only MGm projects to layer VI of primary auditory and temporal association cortices. Within the perirhinal cortex zones of convergence and divergence exist. The present results demonstrate a differential thalamocortical projection of single thalamic nuclei to those cortical areas which are involved in the transmission of sensory signals to the amygdala via the thalamocortico-cortical pathway and to the hippocampus via the entorhinal cortex. The thalamic nuclei are thus in a position to activate the amygdala and to modulate the information flow of the thalamocortico-cortical pathway to both amygdala and hippocampus.

关键词：轴突运输生物素/类似物和衍生物大脑皮质/解剖学和组织学大脑皮质/细胞学右旋糖酐类荧光染料膝状体/解剖学和组织学微量注射神经通路/解剖学和组织学神经元/细胞学突触前末梢大鼠 Sprague-Dawley 大鼠 Wistar 若丹明类颞叶/解剖学和组织学丘脑核/解剖学和组织学动物男(雄)性大鼠

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A neural model of motion processing and visual navigation by cortical area MST

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CEREBRAL CORTEX 1999年第8期9卷 878-895页

作者： Grossberg, S Mingolla, E Pack, C Boston Univ Dept Cognit & Neural Syst Boston MA 02215 USA Boston Univ Ctr Adapt Syst Boston MA 02215 USA

Cells in the dorsal medial superior temporal cortex (MSTd) process optic flow generated by self-motion during visually guided navigation. A neural model shows how interactions between well-known neural mechanisms (log polar cortical magnification, Gaussian motion-sensitive receptive fields, spatial pooling of motion-sensitive signals and subtractive extraretinal eye movement signals) lead to emergent properties that quantitatively simulate neurophysiological data about MSTd cell properties and psychophysical data about human navigation. Model cells match MSTd neuron responses to optic flow stimuli placed in different parts of the visual field, including position invariance, tuning curves, preferred spiral directions, direction reversals, average response curves and preferred locations for stimulus motion centers. The model shows how the preferred motion direction of the most active MSTd cells can explain human judgments of self-motion direction (heading), without using complex heading templates. The model explains when extraretinal eye movement signals are needed for accurate heading perception, and when retinal input is sufficient, and how heading judgments depend on scene layouts and rotation rates.

关键词：算法眼球运动/生理学模型神经学视网膜/解剖学和组织学视网膜/生理学颞叶/解剖学和组织学颞叶/生理学视皮质/解剖学和组织学视皮质/生理学视通路/解剖学和组织学视通路/生理学人类

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SUBICULAR INPUT FROM TEMPORAL CORTEX IN THE RHESUS-MONKEY

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SCIENCE 1979年第4406期205卷 608-610页

作者： VANHOESEN, GW ROSENE, DL MESULAM, MM UNIV IOWA DEPT NEUROL IOWA CITY IA 52242 USA BOSTON UNIV SCH MED DEPT ANAT BOSTON MA 02118 USA BETH ISRAEL HOSP HARVARD NEUROL UNIT BULLARD & DENNY BROWN LABS BOSTON MA 02215 USA

The subicular cortices of the primate hippocampal formation form a physical and connectional link between the cortex of the temporal lobe and the hippocampus. Their direct connections with all classes of cortex in the temporal lobe except primary sensory cortex underscore the pivotal role of these areas in the potential interplay between the hippocampal formation and the association cortices.

关键词：氨基酸类/代谢类人猿亚目海马/解剖学和组织学海马/生理学恒河猴颞叶/解剖学和组织学颞叶/生理学动物

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An fMRI version of the Farnsworth-Munsell 100-Hue test reveals multiple color-selective areas in human ventral occipitotemporal cortex

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CEREBRAL CORTEX 1999年第3期9卷 257-263页

作者： Beauchamp, MS Haxby, JV Jennings, JE DeYoe, EA NIMH Sect Funct Brain Imaging Lab Brain & Cognit Bethesda MD 20892 USA Med Coll Wisconsin Dept Cellular Biol & Anat Milwaukee WI 53226 USA

Studies of patients with cerebral achromatopsia have suggested that ventral occipitotemporal cortex is important for color perception. We created a functional magnetic resonance imaging (fMRI) version of a clinical test commonly used to assess achromatopsia, the Farnsworth-Munsell 100-Hue test. The test required normal subjects to use color information in the visual stimulus to perform a color sequencing task. A modification of the test requiring ordering by luminance was used as a control task. Subjects were also imaged as they passively viewed colored stimuli. A limited number of areas responded more to chromatic than achromatic stimulation, including primary visual cortex. Most color-selective activity was concentrated in ventral occipitotemporal cortex. Several areas in ventral cortex were identified. The most posterior, located in posterior fusiform gyrus, corresponded to the area activated by passive viewing of colored stimuli. More anterior and medial color-selective areas were located in the collateral sulcus and fusiform gyrus. These more anterior areas were not identified in previous imaging studies which used passive viewing of colored stimuli, and were most active in our study when visual color information was behaviorally relevant, suggesting that attention influences activity in color-selective areas, The fMRI version of the Farnsworth-Munsell test may be useful in the study of achromatopsia.

关键词：适应生理学色觉试验磁共振成像/方法枕叶/解剖学和组织学参考值颞叶/解剖学和组织学成年人女(雌)性人类男(雄)性

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