Faculty Opinions recommendation of Neural representations of faces and body parts in macaque and human cortex: a comparative FMRI study.

2013 ◽  
Author(s):  
Winrich Freiwald
Keyword(s):  
Body Parts ◽  
Human Cortex ◽  
Neural Representations ◽  
Fmri Study

Spatial updating in human cortex: An event-related fMRI study at 3T

NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 333
Author(s):  
Elisha P. Merriam ◽  
Carol L. Colby
Keyword(s):  
Spatial Updating ◽  
Human Cortex ◽  
Fmri Study

scholarly journals Shared neural representations of cognitive conflict and negative affect in the medial frontal cortex

2019 ◽  
Author(s):  
Luc Vermeylen ◽  
David Wisniewski ◽  
Carlos González-García ◽  
Vincent Hoofs ◽  
Wim Notebaert ◽  
...  
Keyword(s):  
Negative Affect ◽  
Frontal Cortex ◽  
Supplementary Motor Area ◽  
Cognitive Conflict ◽  
Medial Frontal Cortex ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Neural Representations ◽  
Fmri Study ◽  
Multivariate Pattern

AbstractInfluential theories of medial frontal cortex (MFC) function suggest that the MFC registers cognitive conflict as an aversive signal, but no study directly tested this idea. Instead, recent studies suggested that non-overlapping regions in the MFC process conflict and affect. In this pre-registered human fMRI study, we used multivariate pattern analyses to identify which regions respond similarly to conflict and aversive signals. The results reveal that, of all conflict- and value-related regions, the ventral pre-supplementary motor area (or dorsal anterior cingulate cortex) showed a shared neural pattern response to different conflict and affect tasks. These findings challenge recent conclusions that conflict and affect are processed independently, and provide support for integrative views of MFC function.

scholarly journals The representational space of observed actions

2019 ◽  
Author(s):  
Raffaele Tucciarelli ◽  
Moritz F. Wurm ◽  
Elisa Baccolo ◽  
Angelika Lingnau
Keyword(s):  
Parietal Lobe ◽  
Large Set ◽  
Body Parts ◽  
Inferior Parietal Lobe ◽  
Neural Representations ◽  
Representational Space ◽  
Left Posterior ◽  
Human Capability ◽  
Occipitotemporal Cortex ◽  
Organizing Principles

AbstractCategorizing and understanding other people’s actions is a key human capability. Whereas there exists a growing literature regarding the organization of objects, the representational space underlying the organization of observed actions remain largely unexplored. Here we examined the organizing principles of a large set of actions and the corresponding neural representations. Using multiple-regression representational similarity analysis of fMRI data, in which we accounted for variability due to major action-related features (body parts, scenes, movements, objects), we found that the semantic dissimilarity structure was best captured by patterns of activation in the lateral occipitotemporal cortex (LOTC) and the left posterior inferior parietal lobe (IPL). Together, our results demonstrate that the organization of observed actions in the LOTC and the IPL resembles the organizing principles used by participants to classify actions behaviorally, in line with the view that these regions are crucial for accessing the meaning of actions.

scholarly journals Learning hierarchical sequence representations across human cortex and hippocampus

2019 ◽  
Author(s):  
Simon Henin ◽  
Nicholas B. Turk-Browne ◽  
Daniel Friedman ◽  
Anli Liu ◽  
Patricia Dugan ◽  
...  
Keyword(s):  
Human Subjects ◽  
Ordinal Position ◽  
Brain Areas ◽  
Human Cortex ◽  
Neural Representations ◽  
Early Processing ◽  
Multiple Levels ◽  
Transitional Probabilities ◽  
Intracranial Electrodes ◽  
Computational Systems

ABSTRACTSensory input arrives in continuous sequences that humans experience as units, e.g., words and events. The brain’s ability to discover extrinsic regularities is called statistical learning. Structure can be represented at multiple levels, including transitional probabilities, ordinal position, and identity of units. To investigate sequence encoding in cortex and hippocampus, we recorded from intracranial electrodes in human subjects as they were exposed to auditory and visual sequences containing temporal regularities. We find neural tracking of regularities within minutes, with characteristic profiles across brain areas. Early processing tracked lower-level features (e.g., syllables) and learned units (e.g., words); while later processing tracked only learned units. Learning rapidly shaped neural representations, with a gradient of complexity from early brain areas encoding transitional probability, to associative regions and hippocampus encoding ordinal position and identity of units. These findings indicate the existence of multiple, parallel computational systems for sequence learning across hierarchically organized cortico-hippocampal circuits.

scholarly journals Narratives as Networks: Predicting Memory from the Structure of Naturalistic Events

2021 ◽  
Author(s):  
Hongmi Lee ◽  
Janice Chen
Keyword(s):  
Memory Consolidation ◽  
Human Life ◽  
Discrete Events ◽  
Cortical Areas ◽  
Neural Representations ◽  
Causal Connections ◽  
Fmri Study ◽  
Memory Representations ◽  
Event Boundary ◽  
With Memory

ABSTRACTHuman life consists of a multitude of diverse and interconnected events. However, extant research has focused on how humans segment and remember discrete events from continuous input, with far less attention given to how the structure of connections between events impacts memory. We conducted an fMRI study in which subjects watched and recalled a series of realistic audiovisual narratives. By transforming narratives into networks of events, we found that more central events—those with stronger semantic or causal connections to other events—were better remembered. During encoding, central events evoked larger hippocampal event boundary responses associated with memory consolidation. During recall, high centrality predicted stronger activation in cortical areas involved in episodic recollection, and more similar neural representations across individuals. Together, these results suggest that when humans encode and retrieve complex real-world experiences, the reliability and accessibility of memory representations is shaped by their location within a network of events.

scholarly journals Fast event-related mapping of fingertip population receptive fields in human somatosensory and motor cortex

2022 ◽  
Author(s):  
Sarah Khalife ◽  
Susan T. Francis ◽  
Denis Schluppeck ◽  
Rosa-Maria Sanchez-Panchuelo ◽  
Julien Besle
Keyword(s):  
Receptive Fields ◽  
7 Tesla ◽  
Body Parts ◽  
Stimulus Interval ◽  
Human Cortex ◽  
Body Representations ◽  
Robust Estimates ◽  
Tuning Width ◽  
Brodmann Areas ◽  
Central Gyrus

The majority of fMRI studies investigating somatotopic body representations in the human cortex have used either block or phase-encoding stimulation designs. Event-related (ER) designs allow for more natural and flexible stimulation sequences, while enabling the independent estimation of responses to different body parts in the same cortical location. Here we compared an efficiency-optimized fast ER design (2s inter stimulus interval, ISI) to a slow ER design (8s ISI) for mapping fingertip voxelwise tuning properties in the sensorimotor cortex of 6 participants at 7 Tesla. The fast ER design resulted in similar, but more robust, estimates compared to the slow ER design. Concatenating the fast and slow ER data, we demonstrate in each individual brain the existence of two separate somatotopically-organized representations of the fingertips, one in S1 on the post-central gyrus and the other at the border of the motor and pre-motor cortices on the pre-central gyrus. In both post-central and pre-central representations, fingertip tuning width increases progressively, from narrowly-tuned Brodmann areas 3b and 4a respectively, towards parietal and frontal regions responding equally to all fingertips.

Neural representations of two-digit numbers: A parametric fMRI study

NeuroImage ◽  
2006 ◽  
Vol 29 (2) ◽  
pp. 358-367 ◽  
Author(s):  
Guilherme Wood ◽  
Hans-Christoph Nuerk ◽  
Klaus Willmes
Keyword(s):  
Neural Representations ◽  
Fmri Study

scholarly journals Suppression weakens unwanted memories via a sustained reduction of neural reactivation

2021 ◽  
Author(s):  
Ann-Kristin Meyer ◽  
Roland G. Benoit
Keyword(s):  
Intrusive Memories ◽  
Neural Representations ◽  
Parahippocampal Cortex ◽  
Aversive Events ◽  
Fmri Study ◽  
Sustained Reduction ◽  
Memory Representations ◽  
Scene Information ◽  
The Right ◽  
Study Participants

Aversive events often turn into intrusive memories. However, prior evidence indicates that these memories can be forgotten via a mechanism of retrieval suppression. Here, we test the hypothesis that suppression weakens memories by deteriorating their neural representations. This deterioration, in turn, would hinder their subsequent reactivation and thus impoverish the vividness with which they can be recalled. In an fMRI study, participants repeatedly suppressed memories of aversive scenes. As predicted, this process rendered the memories less vivid. Using a pattern classifier, we observed that it did diminish the reactivation of scene information both globally across the grey matter and locally in the parahippocampal cortices. Moreover, in the right parahippocampal cortex, a stronger decline in vividness was associated with a greater reduction in generic reactivation of scene information and in the specific reinstatement of unique memory representations. These results support the hypothesis that suppression deteriorates memories by compromising their neural representations.

Polymodal object representation in the human cortex. An fMRI-study

NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 864
Author(s):  
F. Binkofski ◽  
G. Buccino ◽  
N.J. Shah ◽  
K. Zilles ◽  
G.R. Fink
Keyword(s):  
Object Representation ◽  
Human Cortex ◽  
Fmri Study
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