scholarly journals Neural correlates of tactile simultaneity judgement: a functional magnetic resonance imaging study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Takahiro Kimura ◽  
Hiroshi Kadota ◽  
Tsuyoshi Kuroda ◽  
Tomomi D. Funai ◽  
Makoto Iwata ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Neural Correlates ◽  
Time Range ◽  
Statistical Criterion ◽  
Time Interval ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Right

AbstractSimultaneity judgement (SJ) is a temporal discrimination task in which the targets span an ultimately short time range (zero or not). Psychophysical studies suggest that SJ is adequate to probe the perceptual components of human time processing in pure form. Thus far, time-relevant neural correlates for tactile SJ are unclear. We performed functional magnetic resonance imaging (fMRI) to investigate the neural correlates of tactile SJ using tactile number judgement as a time-irrelevant control task. As our main result, we demonstrated that the right inferior parietal lobule (IPL) is an SJ-specific region. The right IPL was detected by both parametric and non-parametric statistical analyses, and its activation intensity fulfilled a strict statistical criterion. In addition, we observed that some left-dominant regions (e.g., the striatum) were specifically activated by successive stimuli during SJ. Meanwhile, no region was specifically activated by simultaneous stimuli during SJ. Accordingly, we infer that the neural process for tactile SJ is as follows: the striatum estimates the time interval between tactile stimuli; based on this interval, the right IPL discriminates the successiveness or simultaneity of the stimuli. Moreover, taking detailed behavioural results into account, we further discuss possible concurrent or alternative mechanisms that can explain the fMRI results.

scholarly journals Resting-State Functional Magnetic Resonance Imaging and Functional Connectivity Density Mapping in Patients With Optic Neuritis

2021 ◽  
Vol 15 ◽  
Author(s):  
Ke Song ◽  
Yong Wang ◽  
Mei-Xia Ren ◽  
Jiao Li ◽  
Ting Su ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Optic Neuritis ◽  
Resting State ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Connectivity Density ◽  
The Right

Background: Using resting-state functional connectivity (rsFC), we investigated alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with optic neuritis (ON).Methods: We enrolled 28 patients with ON (18 males, 10 females) and 24 healthy controls (HCs; 16 males, 8 females). All subjects underwent functional magnetic resonance imaging (fMRI) in a quiet state to determine the values of rsFC, long-range FCD (longFCD), and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were generated to distinguish patients from HCs.Results: The ON group exhibited obviously lower longFCD values in the left inferior frontal gyrus triangle, the right precuneus and the right anterior cingulate, and paracingulate gyri/median cingulate and paracingulate gyri. The left median cingulate and paracingulate gyri and supplementary motor area (SMA) were also significantly lower. Obviously reduced IFCD values were observed in the left middle temporal gyrus/angular gyrus/SMA and right cuneus/SMA compared with HCs.Conclusion: Abnormal neural activities were found in specific brain regions in patients with ON. Specifically, they showed significant changes in rsFC, longFCD, and IFCD values. These may be useful to identify the specific mechanism of change in brain function in ON.

Investigating the Neural Correlates of the Affect Heuristic Using Functional Magnetic Resonance Imaging

2021 ◽  
pp. 1-14
Author(s):  
Kenny Skagerlund ◽  
Mikael Skagenholt ◽  
Paul J. Hamilton ◽  
Paul Slovic ◽  
Daniel Västfjäll
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Inferior Frontal Gyrus ◽  
Neural Correlates ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Left Inferior Frontal Gyrus ◽  
Affect Heuristic ◽  
Medial Frontal Gyrus

Abstract This study investigated the neural correlates of the so-called “affect heuristic,” which refers to the phenomenon whereby individuals tend to rely on affective states rather than rational deliberation of utility and probabilities during judgments of risk and utility of a given event or scenario. The study sought to explore whether there are shared regional activations during both judgments of relative risk and relative benefit of various scenarios, thus being a potential candidate of the affect heuristic. Using functional magnetic resonance imaging, we developed a novel risk perception task, based on a preexisting behavioral task assessing the affect heuristic. A whole-brain voxel-wise analysis of a sample of participants (n = 42) during the risk and benefit conditions revealed overlapping clusters in the left insula, left inferior frontal gyrus, and left medial frontal gyrus across conditions. Extraction of parameter estimates of these clusters revealed that activity of these regions during both tasks was inversely correlated with a behavioral measure assessing the inclination to use the affect heuristic. More activity in these areas during risk judgments reflect individuals' ability to disregard momentary affective impulses. The insula may be involved in integrating viscero-somatosensory information and forming a representation of the current emotional state of the body, whereas activity in the left inferior frontal gyrus and medial frontal gyrus indicates that executive processes may be involved in inhibiting the impulse of making judgments in favor of deliberate risk evaluations.

scholarly journals Remember/Know Judgments Probe Degrees of Recollection

2008 ◽  
Vol 20 (3) ◽  
pp. 400-405 ◽  
Author(s):  
Peter E. Wais ◽  
Laura Mickes ◽  
John T. Wixted
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Semantic Memory ◽  
Source Memory ◽  
Neural Correlates ◽  
Implicit Assumption ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Lesion Studies

Remembering and knowing are states of awareness that accompany the retrieval of facts, faces, and experiences from our past. Although originally intended to separate episodic from semantic memory, the dominant view today is that recollection-based decisions underlie remember responses, whereas familiarity-based decisions underlie know responses. Many functional magnetic resonance imaging (fMRI) studies as well as lesion studies have relied on the remember/know procedure to identify the neural correlates of recollection and familiarity. An implicit assumption of this approach is that know responses, which are thought to tap familiarity-based decisions, are devoid of recollection. We investigated this issue by using a source memory procedure and found that the accuracy of source recollection was significantly above chance for studied words that were declared to be old and known. Critically, this held true even when the source decision was made before the old/new decision (i.e., even after successful recollection had just occurred). Our results show that although recollection and familiarity may be different processes, the remember/know paradigm does not probe them directly. As such, dissociations involving remember/know judgments in fMRI studies and in studies involving amnesic patients should not be construed as dissociations between recollection and familiarity.

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