共查询到20条相似文献,搜索用时 31 毫秒
1.
Objects seen from unusual relative to more canonical views require more time to categorize and recognize, and, according to object model verification theories, additionally recruit prefrontal processes for cognitive control that interact with parietal processes for mental rotation. To test this using functional magnetic resonance imaging, people categorized and recognized known objects from unusual and canonical views. Canonical views activated some components of a default network more on categorization than recognition. Activation to unusual views showed that both ventral and dorsal visual pathways, and prefrontal cortex, have key roles in visual object constancy. Unusual views activated object-sensitive and mental rotation (and not saccade) regions in ventrocaudal intraparietal, transverse occipital, and inferotemporal sulci, and ventral premotor cortex for verification processes of model testing on any task. A collateral-lingual sulci "place" area activated for mental rotation, working memory, and unusual views on correct recognition and categorization trials to accomplish detailed spatial matching. Ventrolateral prefrontal cortex and object-sensitive lateral occipital sulcus activated for mental rotation and unusual views on categorization more than recognition, supporting verification processes of model prediction. This visual knowledge framework integrates vision and memory theories to explain how distinct prefrontal-posterior networks enable meaningful interactions with objects in diverse situations. 相似文献
2.
Mechelli A Price CJ Friston KJ Ishai A 《Cerebral cortex (New York, N.Y. : 1991)》2004,14(11):1256-1265
Functional magnetic resonance imaging (fMRI) studies have identified category-selective regions in ventral occipito-temporal cortex that respond preferentially to faces and other objects. The extent to which these patterns of activation are modulated by bottom-up or top-down mechanisms is currently unknown. We combined fMRI and dynamic causal modelling to investigate neuronal interactions between occipito-temporal, parietal and frontal regions, during visual perception and visual imagery of faces, houses and chairs. Our results indicate that, during visual perception, category-selective patterns of activation in extrastriate cortex are mediated by content-sensitive forward connections from early visual areas. In contrast, during visual imagery, category-selective activation is mediated by content-sensitive backward connections from prefrontal cortex. Additionally, we report content-unrelated connectivity between parietal cortex and the category-selective regions, during both perception and imagery. Thus, our investigation revealed that neuronal interactions between occipito-temporal, parietal and frontal regions are task- and stimulus-dependent. Sensory representations of faces and objects are mediated by bottom-up mechanisms arising in early visual areas and top-down mechanisms arising in prefrontal cortex, during perception and imagery respectively. Additionally non-selective, top-down processes, originating in superior parietal areas, contribute to the generation of mental images, regardless of their content, and their maintenance in the 'mind's eye'. 相似文献
3.
Voss JL Reber PJ Mesulam MM Parrish TB Paller KA 《Cerebral cortex (New York, N.Y. : 1991)》2008,18(7):1712-1719
Familiarity refers to an explicit recognition experience without any necessary retrieval of specific detail related to the episode during which initial learning transpired. Prior experience can also implicitly influence subsequent processing through a memory phenomenon termed conceptual priming, which occurs without explicit awareness of recognition. Resolving current theoretical controversy on relationships between familiarity and conceptual priming requires a clarification of their neural substrates. Accordingly, we obtained functional magnetic resonance images in a novel paradigm for separately assessing neural correlates of familiarity and conceptual priming using famous and nonfamous faces. Conceptual priming, as shown by more accurate behavioral responses to strongly conceptually primed than to weakly conceptually primed faces, was associated with activity reductions in left prefrontal cortex, whereas familiarity was associated with activity enhancements in right parietal cortex for more-familiar compared with less-familiar faces. This neuroimaging evidence implicates separate neurocognitive processes operative in explicit stimulus recognition versus implicit conceptual priming. 相似文献
4.
Borra E Belmalih A Calzavara R Gerbella M Murata A Rozzi S Luppino G 《Cerebral cortex (New York, N.Y. : 1991)》2008,18(5):1094-1111
We traced the cortical connections of the anterior intraparietal (AIP) area, which is known to play a crucial role in visuomotor transformations for grasping. AIP displayed major connections with 1) areas of the inferior parietal lobule convexity, the rostral part of the lateral intraparietal area and the SII region; 2) ventral visual stream areas of the lower bank of the superior temporal sulcus and the middle temporal gyrus; and 3) the premotor area F5 and prefrontal areas 46 and 12. Additional connections were observed with the caudal intraparietal area and the ventral part of the frontal eye field. This study suggests that visuomotor transformations for object-oriented actions, processed in AIP, rely not only on dorsal visual stream information related to the object's physical properties but also on ventral visual stream information related to object identity. The identification of direct anatomical connections with the inferotemporal cortex suggests that AIP also has a unique role in linking the parietofrontal network of areas involved in sensorimotor transformations for grasping with areas involved in object recognition. Thus, AIP could represent a crucial node in a cortical circuit in which hand-related sensory and motor signals gain access to representations of object identity for tactile object recognition. 相似文献
5.
The parietal cortex has traditionally been implicated in spatial attention and eye-movement processes. Recent functional neuroimaging studies have found that activation in the parietal cortex is related to successful recognition memory. The activated regions consistently include the intraparietal sulcus in the lateral parietal cortex and the precuneus in the medial parietal cortex. However, little is known about the functional differences between lateral and medial parietal cortices in the memory retrieval process. In this study, we examined whether the human lateral and medial parietal lobes have differential anatomical and functional connectivity with the temporal lobe. To this end, we used functional magnetic resonance imaging to constrain the analysis of anatomical connectivity obtained by diffusion tensor imaging (DTI). Both DTI tractography and functional connectivity analysis showed that the lateral parietal region has anatomical and functional connections with the lateral temporal lobe, and the medial parietal region has connections with the medial temporal lobe. These results suggest the existence of segregated lateral and medial parieto-temporal pathways in successful memory retrieval. 相似文献
6.
O'Neil EB Protzner AB McCormick C McLean DA Poppenk J Cate AD Köhler S 《Cerebral cortex (New York, N.Y. : 1991)》2012,22(1):74-85
Traditionally, the medial temporal lobe (MTL) is thought to be dedicated to declarative memory. Recent evidence challenges this view, suggesting that perirhinal cortex (PrC), which interfaces the MTL with the ventral visual pathway, supports highly integrated object representations in recognition memory and perceptual discrimination. Even with comparable representational demands, perceptual and memory tasks differ in numerous task demands and the subjective experience they evoke. Here, we tested whether such differences are reflected in distinct patterns of connectivity between PrC and other cortical regions, including differential involvement of prefrontal control processes. We examined functional magnetic resonance imaging data for closely matched perceptual and recognition memory tasks for faces that engaged right PrC equivalently. Multivariate seed analyses revealed distinct patterns of interactions: Right ventrolateral prefrontal and posterior cingulate cortices exhibited stronger functional connectivity with PrC in recognition memory; fusiform regions were part of the pattern that displayed stronger functional connectivity with PrC in perceptual discrimination. Structural equation modeling revealed distinct patterns of effective connectivity that allowed us to constrain interpretation of these findings. Overall, they demonstrate that, even when MTL structures show similar involvement in recognition memory and perceptual discrimination, differential neural mechanisms are reflected in the interplay between the MTL and other cortical regions. 相似文献
7.
Dissociable functional cortical topographies for working memory maintenance of voice identity and location 总被引:3,自引:0,他引:3
Rämä P Poremba A Sala JB Yee L Malloy M Mishkin M Courtney SM 《Cerebral cortex (New York, N.Y. : 1991)》2004,14(7):768-780
In order to ascertain whether the neural system for auditory working memory exhibits a functional dissociation for spatial and nonspatial information, we used functional magnetic resonance imaging and a single set of auditory stimuli to study working memory for the location and identity of human voices. The subjects performed a delayed recognition task for human voices and voice locations and an auditory sensorimotor control task. Several temporal, parietal, and frontal areas were activated by both memory tasks in comparison with the control task. However, during the delay periods, activation was greater for the location than for the voice identity task in dorsal prefrontal (SFS/PreCG) and parietal regions and, conversely, greater for voices than locations in ventral prefrontal cortex and the anterior portion of the insula. This preferential response to the voice identity task in ventral prefrontal cortex continued during the recognition test period, but the double dissociation was observed only during maintenance, not during encoding or recognition. Together, the present findings suggest that, during auditory working memory, maintenance of spatial and nonspatial information modulates activity preferentially in a dorsal and a ventral auditory pathway, respectively. Furthermore, the magnitude of this dissociation seems to be dependent on the cognitive operations required at different times during task performance. 相似文献
8.
Sarpal D Buchsbaum BR Kohn PD Kippenhan JS Mervis CB Morris CA Meyer-Lindenberg A Berman KF 《Cerebral cortex (New York, N.Y. : 1991)》2008,18(10):2402-2409
Williams syndrome (WS) is a rare neurodevelopmental disorder caused by a 1.6 Mb microdeletion on chromosome 7q11.23 and characterized by hypersocial personality and prominent visuospatial construction impairments. Previous WS studies have identified functional and structural abnormalities in the hippocampal formation, prefrontal regions crucial for amygdala regulation and social cognition, and the dorsal visual stream, notably the intraparietal sulcus (IPS). Although aberrant ventral stream activation has not been found in WS, object-related visual information that is processed in the ventral stream is a critical source of input into these abnormal regions. The present study, therefore, examined neural interactions of ventral stream areas in WS. Using a passive face- and house-viewing paradigm, activation and functional connectivity of stimulus-selective regions in fusiform and parahippocampal gyri, respectively, were investigated. During house viewing, significant activation differences were observed between participants with WS and a matched control group in IPS. Abnormal functional connectivity was found between parahippocampal gyrus and parietal cortex and between fusiform gyrus and a network of brain regions including amygdala and portions of prefrontal cortex. These results indicate that abnormal upstream visual object processing may contribute to the complex cognitive/behavioral phenotype in WS and provide a systems-level characterization of genetically mediated abnormalities of neural interactions. 相似文献
9.
Perceptual and Cognitive Visual Functions of Parietal and Temporal Cortices in the Cat 总被引:9,自引:4,他引:5
Lomber Stephen G.; Payne Bertram R.; Cornwell Paul; Long Kevin D. 《Cerebral cortex (New York, N.Y. : 1991)》1996,6(5):673-695
We used reversible cooling deactivation to compare the functionsof cortices lining the middle suprasylvian (MS) sulcus and formingthe ventral portion of the posterior suprasylvian (vPS) gyrus.A battery of attentional, motion and mnemonic processing taskswere used and performance was examined during deactivation ofeach region. The results show a clear dissociation of functions.Deactivation of MS cortex resulted in profound deficits on avisual orienting task and on the discrimination of directionof motion, whereas deactivation of vPS cortex severely impairedboth retention and learning of novel and overlearned objectdiscriminations. In addition, deactivation of either MS or vPScortex impaired discrimination of learned patterns when componentsof the patterns were in motion, whereas only deactivation ofvPS cortex impaired the discrimination when all components werestatic. Together, these results show that a region of parietalcortex contributes to the processing of visual motion and toattentional processes, whereas a region of temporal cortex contributesto the learning and recognition of three-dimensional objectsand two-dimensional patterns. This functional dissociation islinked to differences in underlying visual pathways, which havemany features in common with the parietal and temporal visualprocessing streams previously identified in monkeys and humans.Furthermore, the broad similarity in neural operations carriedout in parietal and temporal cortices of cats, monkeys and humanssuggests the existence of a common plan for cortical processingmachinery within mammals with well developed cerebral cortices. 相似文献
10.
Matching two imagined clocks: the functional anatomy of spatial analysis in the absence of visual stimulation 总被引:2,自引:2,他引:0
Trojano L Grossi D Linden DE Formisano E Hacker H Zanella FE Goebel R Di Salle F 《Cerebral cortex (New York, N.Y. : 1991)》2000,10(5):473-481
Do spatial operations on mental images and those on visually presented material share the same neural substrate? We used the high spatial resolution of functional magnetic resonance imaging to determine whether areas in the parietal lobe that have been implicated in the spatial transformation of visual percepts are also activated during the generation and spatial analysis of imagined objects. Using a behaviourally controlled mental imagery paradigm, which did not involve any visual stimulation, we found robust activation in posterior parietal cortex in both hemispheres. We could thus identify the subset of spatial analysis-related activity that is involved in spatial operations on mental images in the absence of external visual input. This result clarifies the nature of top-down processes in the dorsal stream of the human cerebral cortex and provides evidence for a specific convergence of the pathways of imagery and visual perception within the parietal lobes. 相似文献
11.
Age-related declines in source memory have been observed for various stimuli and associated details. These impairments may be related to alterations in brain regions contributing to source memory via material-independent processes and/or regions specialized for processing specific materials. Using event-related functional magnetic resonance imaging, we investigate the effects of aging on source memory and associated neural activity for words and objects. Source accuracy was equally impaired in older adults for both materials. Imaging data revealed both groups recruited similar networks of regions to support source memory accuracy irrespective of material, including parietal and prefrontal cortices (PFC) and the hippocampus. Age-related decreases in material-independent activity linked to postretrieval monitoring were observed in right lateral PFC. Additionally, age-related increases in source accuracy effects were shown in perirhinal cortex, which were positively correlated with performance in older adults, potentially reflecting functional compensation. In addition to group differences in material-independent regions, age-related crossover interactions for material-dependent source memory effects were observed in regions selectively engaged by objects. These results suggest that older adults' source memory impairments reflect alterations in regions making material-independent contributions to source memory retrieval, primarily the lateral PFC, but may be further impacted by changes in regions sensitive to particular materials. 相似文献
12.
The different neural correlates of action and functional knowledge in semantic memory: an FMRI study 总被引:1,自引:0,他引:1
Canessa N Borgo F Cappa SF Perani D Falini A Buccino G Tettamanti M Shallice T 《Cerebral cortex (New York, N.Y. : 1991)》2008,18(4):740-751
Previous reports suggest that the internal organization of semantic memory is in terms of different "types of knowledge," including "sensory" (information about perceptual features), "action" (motor-based knowledge of object utilization), and "functional" (abstract properties, as function and context of use). Consistent with this view, a specific loss of action knowledge, with preserved functional knowledge, has been recently observed in patients with left frontoparietal lesions. The opposite pattern (impaired functional knowledge with preserved action knowledge) was reported in association with anterior inferotemporal lesions. In the present study, the cerebral representation of action and functional knowledge was investigated using event-related analysis of functional magnetic resonance imaging data. Fifteen subjects were presented with pictures showing pairs of manipulable objects and asked whether the objects within each pair were used with the same manipulation pattern ("action knowledge" condition) or in the same context ("functional knowledge" condition). Direct comparisons showed action knowledge, relative to functional knowledge, to activate a left frontoparietal network, comprising the intraparietal sulcus, the inferior parietal lobule, and the dorsal premotor cortex. The reverse comparison yielded activations in the retrosplenial and the lateral anterior inferotemporal cortex. These results confirm and extend previous neuropsychological data and support the hypothesis of the existence of different types of information processing in the internal organization of semantic memory. 相似文献
13.
Naming pictures of objects from different categories (e.g. animals or tools) evokes maximal responses in different brain regions. However, these 'category-specific' regions typically respond to other object categories as well. Here we used stimulus familiarity to further investigate category representation. Naming pictures of animals and tools elicited category-related activity in a number of previously identified regions. This activity was reduced for familiar relative to novel stimuli. Reduced activation occurred in all object responsive areas in the ventral occipito-temporal cortex, regardless of which category initially produced the maximal response. This suggests that object representations in the ventral occipito-temporal cortex are not limited to a discrete area, but rather are widespread and overlapping. In other regions (e.g. the lateral temporal and left premotor cortices), experience-dependent reductions were category specific. Together, these findings suggest that category-related activations reflect the retrieval of information about category-specific features and attributes. 相似文献
14.
Paz-Alonso PM Ghetti S Donohue SE Goodman GS Bunge SA 《Cerebral cortex (New York, N.Y. : 1991)》2008,18(9):2208-2216
The Deese/Roediger-McDermott (DRM) false-memory effect has been extensively documented in psychological research. People falsely recognize critical lures or nonstudied items that are semantically associated with studied items. Behavioral research has provided evidence for age-related increases in the DRM false-recognition effect. The present event-related functional magnetic resonance imaging study was aimed at investigating neurodevelopmental changes in brain regions associated with true- and false-memory recognition in 8-year olds, 12-year olds, and adults. Relative to 8-year olds, adults correctly endorsed more studied items as "old" but also mistakenly endorsed more critical lures. Age-related increases in recollection were associated with changes in the medial temporal lobe (MTL) activation profile. Additionally, age-related increases in false alarms (FAs) to semantically related lures were associated with changes in the activation profile of left ventrolateral prefrontal cortex, a region associated with semantic processing. Additional regions exhibiting age-related changes include posterior parietal and anterior prefrontal cortices. In summary, concomitant changes in the MTL, prefrontal cortex, and parietal cortex underlie developmental increases in true and false recognition during childhood and adolescence. 相似文献
15.
When observers must discriminate a weak sensory signal in noise, early sensory areas seem to reflect the instantaneous strength of the sensory signal. In contrast, high-level parietal and prefrontal areas appear to integrate these signals over time with activity peaking at the time of the observer's decision. Here, we used functional magnetic resonance imaging to investigate how the brain forms perceptual decisions about complex visual forms in a challenging task, requiring the discrimination of ambiguous 2-tone Mooney faces and visually similar nonface images. Face-selective areas in the ventral visual cortex showed greater activity when subjects reported perceiving a face as compared with a nonface, even on error trials. More important, activity was closely related to the time of the subject's decision for face judgments, even on individual trials, and resembled the time course of activity in motor cortex corresponding to the subject's behavioral report. These results indicate that perceptual decisions about ambiguous face-like stimuli are reflected early in the sensorimotor pathway, in face-selective regions of the ventral visual cortex. Activity in these areas may represent a potential rate-limiting step in the pathway from sensation to action when subjects must reach a decision about ambiguous face-like stimuli. 相似文献
16.
Poldrack RA; Desmond JE; Glover GH; Gabrieli JD 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(1):1-10
The learning of perceptual skills is thought to rely upon multiple regions
in the cerebral cortex, but imaging studies have not yet provided evidence
about the changes in neural activity that accompany visual skill learning.
Functional magnetic resonance imaging (fMRI) was used to examine changes in
activation of posterior brain regions associated with the acquisition of
mirror-reading skill for novel and practiced stimuli. Multiple regions in
the occipital lobe, inferior temporal cortex, superior parietal cortex and
cerebellum were involved in the reading of mirror-reversed compared to
normally oriented text. For novel stimuli, skilled mirror-reading was
associated with decreased activation in the right superior parietal cortex
and posterior occipital regions and increased activation in the left
inferior temporal lobe. These results suggest that learning to read mirror-
reversed text involves a progression from visuospatial transformation to
direct recognition of transformed letters. Reading practiced, relative to
unpracticed, stimuli was associated with decreased activation in occipital
visual cortices, inferior temporal cortex and superior parietal cortex and
increased activation in occipito-parietal and lateral temporal regions. By
examining skill learning and item- specific repetition priming in the same
task, this study demonstrates that both of these forms of learning exhibit
shifts in the set of neural structures that contribute to performance.
相似文献
17.
Visual pathways for object-oriented action and object recognition: functional anatomy with PET 总被引:8,自引:4,他引:4
Faillenot I; Toni I; Decety J; Gregoire MC; Jeannerod M 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(1):77-85
The purpose of this study was to identify the functional anatomy of the
mechanisms involved in visually guided prehension and in object recognition
in humans. The cerebral blood flow of seven subjects was investigated by
positron emission tomography. Three conditions were performed using the
same set of stimuli. In the 'grasping' condition, subjects were instructed
to accurately grasp the objects. In the 'matching' condition, subjects were
requested to compare the shape of the presented object with that of the
previous one. In the 'pointing' condition (control), subjects pointed
towards the objects. The comparison between grasping and pointing showed a
regional cerebral blood flow (rCBF) increase in the anterior part of the
inferior parietal cortex and part of the posterior parietal cortex. The
comparison between grasping and matching showed an rCBF increase in the
cerebellum, the left frontal cortex around the central sulcus, the mesial
frontal cortex and the left inferior parietal cortex. Finally, the
comparison between matching and pointing showed an rCBF increase in the
right temporal cortex and the right posterior parietal cortex. Thus
object-oriented action and object recognition activate a common posterior
parietal area, suggesting that some kind of within-object spatial analysis
was processed by this area whatever the goal of the task.
相似文献
18.
The role of the inferior parietal cortex in linking the tactile perception and manual construction of object shapes 总被引:3,自引:3,他引:0
Jäncke L Kleinschmidt A Mirzazade S Shah NJ Freund HJ 《Cerebral cortex (New York, N.Y. : 1991)》2001,11(2):114-121
We employed functional magnetic resonance imaging (fMRI) in 12 healthy subjects to measure cerebral activation related to a set of higher order manual sensorimotor tasks performed in the absence of visual guidance. Purposeless manipulation of meaningless plasticine lumps served as a reference against which we contrasted two tasks where manual manipulation served a meaningful purpose, either the perception and recognition of three-dimensional shapes or the construction of such shapes out of an amorphous plasticine lump. These tasks were compared with the corresponding mental imagery of the modelling process which evokes the constructive concept but lacks concomitant sensorimotor input and output. Neural overlap was found in a bilateral activity increase in the posterior and anterior intraparietal sulcus area (IPS and AIP). Differential activation was seen in the supplementary and cingulate motor areas, the left M1 and the superior parietal lobe for modelling and in the left angular and ventral premotor cortex for imagery. Our data thus point to a congruent neural substrate for both perceptive and constructive object-oriented sensorimotor cognition in the AIP and posterior IPS. The leftward asymmetry of the inferior parietal activations, including the angular gyrus, during imagery of modelling along with the ventral premotor activations emphasize the close vicinity of the circuitry for cognitive manipulative motor behaviour and language. 相似文献
19.
Convergence of neural systems processing stimulus associations and coordinating motor responses 总被引:1,自引:1,他引:0
McIntosh AR; Lobaugh NJ; Cabeza R; Bookstein FL; Houle S 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(7):648-659
A sensory-sensory learning paradigm was used to measure neural changes in
humans during acquisition of an association between an auditory and visual
stimulus. Three multivariate partial least-squares (PLS) analyses of
positron emission tomography data identified distributed neural systems
related to (i) processing the significance of the auditory stimulus, (ii)
mediating the acquisition of the behavioral response, and (iii) the spatial
overlap between these two systems. The system that processed the
significance of the tone engaged primarily right hemisphere regions and
included dorsolateral prefrontal cortex, putamen, and inferior parietal and
temporal cortices. Activity changes in left occipital cortex were also
identified, most likely reflecting the learned expectancy of the upcoming
visual event. The system related to behavior was similar to that which
coded the significance of the tone, including dorsal occipital cortex. The
PLS analysis of the concordance between these two systems showed
substantial regional overlap, and included occipital, dorsolateral
prefrontal, and limbic cortices. However, activity in dorsomedial
prefrontal cortex was strictly related to processing the auditory stimulus
and not to behavior. Taken together, the PLS analyses identified a system
that contained a sensory-motor component (comprised of occipital, temporal
association and sensorimotor cortices) and a medial prefrontallimbic
component, that as a group simultaneously embodied the learning-related
response to the stimuli and the subsequent change in behavior.
相似文献
20.
Despite numerous functional neuroimaging and lesion studies of human executive function, the precise neuroanatomical correlates of specific components of attentional control remain controversial. Using a novel approach that focused upon volunteer behavior rather than experimental manipulations, specific components of attentional shifting were fractionated, and their neural correlates differentiated using event-related fMRI. The results demonstrate that the ventrolateral prefrontal cortex is involved in switching attention "between" stimulus dimensions, whereas the posterior parietal cortex mediates changes in stimulus-response mapping. Furthermore, reversals based on negative feedback activated the lateral orbitofrontal cortex, whereas positive feedback modulated activity in the medial orbital frontal cortex. Finally, the dorsolateral prefrontal cortex was active throughout solution search. These findings support the hypothesis that lateral prefrontal, orbital, and parietal areas form a supervisory network that controls the focus of attention and suggests that these regions can be fractionated in terms of their specific contributions. 相似文献