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Cerebral Cortex (New York, N.Y. : 1991) Mar 2010The left parietal lobe has been proposed as a major language area. However, parietal cortical function is more usually considered in terms of the control of actions,...
The left parietal lobe has been proposed as a major language area. However, parietal cortical function is more usually considered in terms of the control of actions, contributing both to attention and cross-modal integration of external and reafferent sensory cues. We used positron emission tomography to study normal subjects while they overtly generated narratives, both spoken and written. The purpose was to identify the parietal contribution to the modality-specific sensorimotor control of communication, separate from amodal linguistic and memory processes involved in generating a narrative. The majority of left and right parietal activity was associated with the execution of writing under visual and somatosensory control irrespective of whether the output was a narrative or repetitive reproduction of a single grapheme. In contrast, action-related parietal activity during speech production was confined to primary somatosensory cortex. The only parietal area with a pattern of activity compatible with an amodal central role in communication was the ventral part of the left angular gyrus (AG). The results of this study indicate that the cognitive processing of language within the parietal lobe is confined to the AG and that the major contribution of parietal cortex to communication is in the sensorimotor control of writing.
Topics: Adult; Aged; Brain Mapping; Female; Functional Laterality; Humans; Language Tests; Male; Memory; Middle Aged; Parietal Lobe; Positron-Emission Tomography; Speech; Verbal Learning; Writing
PubMed: 19531538
DOI: 10.1093/cercor/bhp120 -
Philosophical Transactions of the Royal... Feb 2011We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms... (Review)
Review
We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans--and present additional original data--which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward. This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized.
Topics: Agnosia; Animals; Apraxias; Haplorhini; Humans; Parietal Lobe; Saccades; Space Perception; Visual Perception
PubMed: 21242144
DOI: 10.1098/rstb.2010.0258 -
Neurobiology of Learning and Memory Feb 2009The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two... (Meta-Analysis)
Meta-Analysis Review
The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding.
Topics: Attention; Humans; Learning; Magnetic Resonance Imaging; Memory; Parietal Lobe; Positron-Emission Tomography; Time Factors
PubMed: 19028591
DOI: 10.1016/j.nlm.2008.10.011 -
Trends in Cognitive Sciences Jun 2012Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive... (Review)
Review
Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive operations specific to each domain. In this article, we propose a hypothesis that can account for VPC activations across all the cognitive domains reviewed. We first review VPC activations in the domains of perceptual and motor reorienting, episodic memory retrieval, language and number processing, theory of mind, and episodic memory encoding. Then, we consider the localization of VPC activations across domains and conclude that they are largely overlapping with some differences around the edges. Finally, we assess how well four different hypotheses of VPC function can explain findings in various domains and conclude that a bottom-up attention hypothesis provides the most complete and parsimonious account.
Topics: Attention; Brain Mapping; Cognition; Humans; Magnetic Resonance Imaging; Memory, Episodic; Neural Pathways; Parietal Lobe; Theory of Mind
PubMed: 22609315
DOI: 10.1016/j.tics.2012.04.008 -
Hearing Research Dec 2009Goal-directed behavior can be thought of as dynamic links between sensory stimuli and motor acts. Neural correlates of many of the intermediate events of both auditory... (Review)
Review
Goal-directed behavior can be thought of as dynamic links between sensory stimuli and motor acts. Neural correlates of many of the intermediate events of both auditory and visual goal-directed behaviors are found in the posterior parietal cortex. Here, we review studies that have focused on how neurons in the lateral intraparietal area (area LIP) differentially process auditory and visual stimuli. Together, these studies suggest that area LIP contains a modality-dependent representation that is highly dependent on behavioral context.
Topics: Animals; Attention; Auditory Perception; Behavior; Behavior, Animal; Brain Mapping; Hearing; Humans; Macaca mulatta; Models, Anatomic; Models, Neurological; Neurons; Parietal Lobe; Vision, Ocular; Visual Perception
PubMed: 19450431
DOI: 10.1016/j.heares.2009.01.011 -
Progress in Neurobiology Dec 2020Left parietal cortex has been associated with the human-specific ability of sophisticated tool use. Yet, it is unclear how tool information is represented across senses....
Left parietal cortex has been associated with the human-specific ability of sophisticated tool use. Yet, it is unclear how tool information is represented across senses. Here, we compared auditory and visual tool-specific activations within healthy human subjects to probe the relation of tool-specific networks, uni- and multisensory response properties, and functional and structural connectivity using functional and diffusion-weighted MRI. In each subject, we identified an auditory tool network with regions in left anterior inferior parietal cortex (aud-aIPL), bilateral posterior lateral sulcus, and left inferior precentral sulcus, and a visual tool network with regions in left aIPL (vis-aIPL) and bilateral inferior temporal gyrus. Aud-aIPL was largely separate and anterior/inferior from vis-aIPL, with varying degrees of overlap across subjects. Both regions displayed a strong preference for tools versus other stimuli presented within the same modality. Despite their modality preference, aud-aIPL and vis-aIPL and a region in left inferior precentral sulcus displayed multisensory response properties, as revealed in multivariate analyses. Thus, two largely separate tool networks are engaged by the visual and auditory modalities with nodes in parietal and prefrontal cortex potentially integrating information across senses. The diversification of tool processing in human parietal cortex underpins its critical role in complex object processing.
Topics: Adult; Auditory Perception; Concept Formation; Connectome; Diffusion Tensor Imaging; Female; Humans; Magnetic Resonance Imaging; Male; Nerve Net; Parietal Lobe; Pattern Recognition, Visual
PubMed: 32707071
DOI: 10.1016/j.pneurobio.2020.101889 -
Neuron Apr 2018To compare information and reach decisions effectively, our brain uses multiple heuristics, which can, however, induce biases in behavior. An elegant study by Akrami... (Review)
Review
To compare information and reach decisions effectively, our brain uses multiple heuristics, which can, however, induce biases in behavior. An elegant study by Akrami et al. (2018) finds evidence for one such heuristic in a sensory-based comparison task and identifies its location to the posterior parietal cortex.
Topics: Animals; Decision Making; Heuristics; Humans; Parietal Lobe; Sensory Thresholds
PubMed: 29673478
DOI: 10.1016/j.neuron.2018.04.002 -
ELife Feb 2021In a traditional view, in social cognition, attention is equated with gaze and people track other people's attention by tracking their gaze. Here, we used fMRI to test...
In a traditional view, in social cognition, attention is equated with gaze and people track other people's attention by tracking their gaze. Here, we used fMRI to test whether the brain represents attention in a richer manner. People read stories describing an agent (either oneself or someone else) directing attention to an object in one of two ways: either internally directed (endogenous) or externally induced (exogenous). We used multivoxel pattern analysis to examine how brain areas within the theory-of-mind network encoded attention type and agent type. Brain activity patterns in the left temporo-parietal junction (TPJ) showed significant decoding of information about endogenous versus exogenous attention. The left TPJ, left superior temporal sulcus (STS), precuneus, and medial prefrontal cortex (MPFC) significantly decoded agent type (self versus other). These findings show that the brain constructs a rich model of one's own and others' attentional state, possibly aiding theory of mind.
Topics: Adolescent; Adult; Attention; Brain Mapping; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Parietal Lobe; Theory of Mind; Young Adult
PubMed: 33587038
DOI: 10.7554/eLife.63551 -
Annals of Physical and Rehabilitation... Jun 2017Unilateral spatial neglect (USN) is a neurological disorder often observed following damage to the right cerebral hemisphere. Patients with USN are no longer able to... (Review)
Review
Unilateral spatial neglect (USN) is a neurological disorder often observed following damage to the right cerebral hemisphere. Patients with USN are no longer able to take into account stimuli presented on the left side of space. In this article, we will discuss the neuroanatomical correlates that underlie visuospatial attention and can cause USN, an area of growing research interest in the past 20 years. This syndrome has often been related to cortical damage, notably in the inferior parietal lobule. Other data have also implicated lesions in the inferior frontal gyrus or the superior temporal gyrus. In this article, we will highlight the relevance of viewing USN as a disconnection syndrome of interconnected cerebral areas, as opposed to a focal cortical syndrome. We will review data that provide evidence of intrahemispheric disconnection, in particular within the right hemisphere's frontoparietal networks connected by the superior longitudinal fasciculus. Recent findings suggest that interhemispheric disconnection could also contribute to the manifestations of USN. Most importantly, interhemispheric disconnection might be a predictive factor for the chronicity of this disorder. This hypothesis implies that the left hemisphere by itself is not able to compensate for the patients' deficits. Recovery requires the ability to exchange information between the two hemispheres, particularly in the posterior parietal and occipital regions.
Topics: Attention; Brain Mapping; Corpus Callosum; Functional Laterality; Humans; Neuroimaging; Parietal Lobe; Perceptual Disorders; Space Perception; White Matter
PubMed: 26874577
DOI: 10.1016/j.rehab.2016.01.004 -
Neurobiology of Learning and Memory Feb 2009The posterior parietal lobe is known to play some role in a far-flung list of mental processes: linking vision to action (saccadic eye movements, reaching, grasping),... (Review)
Review
The posterior parietal lobe is known to play some role in a far-flung list of mental processes: linking vision to action (saccadic eye movements, reaching, grasping), attending to visual space, numerical calculation, and mental rotation. Here, we review findings from humans and monkeys that illuminate an untraditional function of this region: memory. Our review draws on neuroimaging findings that have repeatedly identified parietal lobe activations associated with short-term or working memory and episodic memory. We also discuss recent neuropsychological findings showing that individuals with parietal lobe damage exhibit both working memory and long-term memory deficits. These deficits are not ubiquitous; they are only evident under certain retrieval demands. Our review elaborates on these findings and evaluates various theories about the mechanistic role of the posterior parietal lobe in memory. The available data point towards the conclusion that the posterior parietal lobe plays an important role in memory retrieval irrespective of elapsed time. However, the available data do not support simple dichotomies such as recall versus recognition, working versus long-term memory. We conclude by formalizing several open questions that are intended to encourage future research in this rapidly developing area of memory research.
Topics: Animals; Attention; Frontal Lobe; Haplorhini; Humans; Magnetic Resonance Imaging; Memory; Models, Neurological; Models, Psychological; Neural Pathways; Neurons; Parietal Lobe; Temporal Lobe
PubMed: 18848635
DOI: 10.1016/j.nlm.2008.09.006