Lag-sensitive repetition suppression effects in the anterior parahippocampal gyrus

Hippocampus ◽  
2005 ◽  
Vol 15 (5) ◽  
pp. 557-561 ◽  
Author(s):  
Craig J. Brozinsky ◽  
Andrew P. Yonelinas ◽  
Neal E.A. Kroll ◽  
Charan Ranganath
Keyword(s):  
Parahippocampal Gyrus ◽  
Repetition Suppression ◽  
Suppression Effects

scholarly journals Repetition Enhancement of Amygdala and Visual Cortex Functional Connectivity Reflects Nonconscious Memory for Negative Visual Stimuli

2016 ◽  
Vol 28 (12) ◽  
pp. 1933-1946 ◽  
Author(s):  
Sarah M. Kark ◽  
Scott D. Slotnick ◽  
Elizabeth A. Kensinger
Keyword(s):  
Functional Connectivity ◽  
Recognition Memory ◽  
Temporal Cortex ◽  
Memory Task ◽  
Emotional Valence ◽  
Activity Levels ◽  
Repetition Effects ◽  
Line Drawings ◽  
Repetition Suppression ◽  
Suppression Effects

Most studies using a recognition memory paradigm examine the neural processes that support the ability to consciously recognize past events. However, there can also be nonconscious influences from the prior study episode that reflect repetition suppression effects—a reduction in the magnitude of activity for repeated presentations of stimuli—that are revealed by comparing neural activity associated with forgotten items to correctly rejected novel items. The present fMRI study examined the effect of emotional valence (positive vs. negative) on repetition suppression effects. Using a standard recognition memory task, 24 participants viewed line drawings of previously studied negative, positive, and neutral photos intermixed with novel line drawings. For each item, participants made an old–new recognition judgment and a sure–unsure confidence rating. Collapsed across valence, repetition suppression effects were found in ventral occipital-temporal cortex and frontal regions. Activity levels in the majority of these regions were not modulated by valence. However, repetition enhancement of the amygdala and ventral occipital-temporal cortex functional connectivity reflected nonconscious memory for negative items. In this study, valence had little effect on activation patterns but had a larger effect on functional connectivity patterns that were markers of nonconscious memory. Beyond memory and emotion, these findings are relevant to other cognitive and social neuroscientists that utilize fMRI repetition effects to investigate perception, attention, social cognition, and other forms of learning and memory.

scholarly journals Neural repetition suppression effects in the human hippocampus

2020 ◽  
Vol 173 ◽  
pp. 107269 ◽  
Author(s):  
Kamin Kim ◽  
Liang-Tien Hsieh ◽  
Josef Parvizi ◽  
Charan Ranganath
Keyword(s):  
Repetition Suppression ◽  
Human Hippocampus ◽  
Suppression Effects

Neural Encoding Correlates of High and Low Verbal Memory Performance

2006 ◽  
Vol 20 (2) ◽  
pp. 68-78 ◽  
Author(s):  
Sibylle Heinze ◽  
Gudrun Sartory ◽  
Bernhard W. Müller ◽  
Armin de Greiff ◽  
Michael Forsting ◽  
...  
Keyword(s):  
Verbal Memory ◽  
Parietal Lobe ◽  
Functional Neuroimaging ◽  
Memory Performance ◽  
Extrastriate Cortex ◽  
Parahippocampal Gyrus ◽  
Premotor Area ◽  
High Performers ◽  
Rehearsal Strategy ◽  
Common Memory

Neuroimaging studies have indicated involvement of left prefrontal cortex and temporal areas in verbal memory processes. The current study used event-related functional neuroimaging to compare encoding of subsequently recalled and not recalled words in high and low memory performers. Fifteen healthy volunteers were given lists of words to learn with immediate recall and to read as a control condition. High performers reported to have visualized the words whereas low performers used a rehearsal strategy. Compared to reading, unsuccessful encoding was associated with thalamic and left premotor area (BA 6) activity. Comparing successful with unsuccessful learning yielded widespread activity of the left prefrontal and posterior temporal gyrus as well as the left superior parietal lobe in the whole group. Low performers showed activation of the left premotor area throughout learning and additionally of the left middle temporal and parahippocampal gyrus during successful encoding. High performers showed increased activation in the extrastriate cortex throughout learning and additionally in the left parietal post- and paracentral areas as well as in the right precuneus during successful encoding. The results suggest that high verbal memory performance is the result of spatiovisual activation concomitant to imagery and low performance of hippocampal and motor activation, the latter being associated with rehearsal, with a common memory circuit subserving both groups.

Ventrolateral Preoptic Nucleus of Hypothalamus: A Possible Target for Deep Brain Stimulation for Treating Sexual Dysfunction

2020 ◽  
Vol 5 (3 And 4) ◽  
pp. 99-102
Author(s):  
Fariborz Ghaffarpasand ◽  
◽  
Mousa Taghipour ◽  
Keyword(s):  
Deep Brain Stimulation ◽  
Sexual Dysfunction ◽  
Sexual Function ◽  
Brain Stimulation ◽  
Sexual Behaviors ◽  
Angular Gyrus ◽  
Parahippocampal Gyrus ◽  
Left Caudate ◽  
Ventrolateral Preoptic Nucleus ◽  
Deep Brain

Sexual function and orientation is a complex platform of human personality which is being modulated by several brain circuities which is less understood currently. Recently, several studies have demonstrated interesting results regarding the role of several brain locations in sexual behaviors and orientation. Sexual arousal in homosexual men is associated with activation of the left angular gyrus, left caudate nucleus, Ventrolateral Preoptic (VLPO) Nucleus of Hypothalamus and right pallidum; while it is associated with bilateral lingual gyrus, right hippocampus, and right parahippocampal gyrus in heterosexual men. We postulate that sexual-orientation behaviors are being mediated by several circuits in the brain in the center of which the VLPO is playing an indistinguishable role. We hypothesize that the different aspects of the sexual dysfunction could be associated with innate or acquired lesions of VLPO. Accordingly, the electrical stimulation of the nucleus in those with sexual dysfunction would be a treatment option. Thus the VLPO could be considered a target for Deep Brain Stimulation (DBS) in individuals with impaired sexual function.

scholarly journals The impact of a multi-domain intervention on cerebral glucose metabolism: analysis from the randomized ancillary FDG PET MAPT trial

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Julien Delrieu ◽  
Thierry Voisin ◽  
Laure Saint-Aubert ◽  
Isabelle Carrie ◽  
Christelle Cantet ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Fdg Pet ◽  
Primary Outcome ◽  
Cognitive Stimulation ◽  
Cerebral Glucose Metabolism ◽  
Parahippocampal Gyrus ◽  
Cerebral Magnetic Resonance Imaging ◽  
Brain Glucose ◽  
Brain Glucose Metabolism ◽  
The Impact

Abstract Background The Multidomain Alzheimer Preventive Trial (MAPT) was designed to assess the efficacy of omega-3 fatty acid supplementation, multidomain intervention (MI), or a combination of both on cognition. Although the MAPT study was negative, an effect of MI in maintaining cognitive functions compared to placebo group was showed in positive amyloid subjects. A FDG PET study (MAPT-NI) was implemented to test the impact of MI on brain glucose metabolism. Methods MAPT-NI was a randomized, controlled parallel-group single-center study, exploring the effect of MI on brain glucose metabolism. Participants were non-demented and had memory complaints, limitation in one instrumental activity of daily living, or slow gait. Participants were randomly assigned (1:1) to “MI group” or “No MI group.” The MI consisted of group sessions focusing on 3 domains: cognitive stimulation, physical activity, nutrition, and a preventive consultation. [18F]FDG PET scans were performed at baseline, 6 months, and 12 months, and cerebral magnetic resonance imaging scans at baseline. The primary objective was to evaluate the MI effect on brain glucose metabolism assessed by [18F]FDG PET imaging at 6 months. The primary outcome was the quantification of regional metabolism rate for glucose in cerebral regions involved early in Alzheimer disease by relative semi-quantitative SUVr (FDG-based AD biomarker). An exploratory voxel-wise analysis was performed to assess the effect of MI on brain glucose metabolism without anatomical hypothesis. Results The intention-to-treat population included 67 subjects (34 in the MI group and 33 in the No MI group. No significant MI effect was observed on primary outcome at 6 months. In the exploratory voxel-wise analysis, we observed a difference in favor of MI group on the change of cerebral glucose metabolism in limbic lobe (right hippocampus, right posterior cingulate, left posterior parahippocampal gyrus) at 6 months. Conclusions MI failed to show an effect on metabolism in FDG-based AD biomarker, but exploratory analysis suggested positive effect on limbic system metabolism. This finding could suggest a delay effect of MI on AD progression. Trial registration ClinicalTrials.gov Identifier, NCT01513252.

scholarly journals Common coding of expected value and value uncertainty memories in the prefrontal cortex and basal ganglia output

2021 ◽  
Vol 7 (20) ◽  
pp. eabe0693
Author(s):  
Ali Ghazizadeh ◽  
Okihide Hikosaka
Keyword(s):  
Prefrontal Cortex ◽  
Basal Ganglia ◽  
Cortical Neurons ◽  
Expected Value ◽  
Common Coding ◽  
Repetition Suppression ◽  
Free Viewing ◽  
Gaze Bias ◽  
Single Unit Recordings ◽  
Value Preferences

Recent evidence implicates both basal ganglia and ventrolateral prefrontal cortex (vlPFC) in encoding value memories. However, comparative roles of cortical and basal nodes in value memory are not well understood. Here, single-unit recordings in vlPFC and substantia nigra reticulata (SNr), within macaque monkeys, revealed a larger value signal in SNr that was nevertheless correlated with and had a comparable onset to the vlPFC value signal. The value signal was maintained for many objects (>90) many weeks after reward learning and was resistant to extinction in both regions and to repetition suppression in vlPFC. Both regions showed comparable granularity in encoding expected value and value uncertainty, which was paralleled by enhanced gaze bias during free viewing. The value signal dynamics in SNr could be predicted by combining responses of vlPFC neurons according to their value preferences consistent with a scheme in which cortical neurons reached SNr via direct and indirect pathways.

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