Development of an fMRI Task for Memory Lateralization Within the Mesial Temporal Lobes

Deficits in central auditory processing may occur in a variety of clinical conditions including traumatic brain injury, neurodegenerative disease, auditory neuropathy/dyssynchrony syndrome, neurological disorders associated with aging, and aphasia. Deficits in central auditory processing of a more subtle nature have also been studied extensively in neurodevelopmental disorders in children with learning disabilities, ADD, and developmental language disorders. Illustrative cases are reviewed demonstrating the use of an audiological test battery in patients with auditory neuropathy/dyssynchrony syndrome, bilateral lesions to the inferior colliculi, and bilateral lesions to the temporal lobes. Electrophysiological tests of auditory function were utilized to define the locus of dysfunction at neural levels ranging from the auditory nerve, midbrain, and cortical levels.

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Evidence for a gradient within the medial temporal lobes for flexible retrieval under hierarchical task rules

Hippocampus ◽

10.1002/hipo.23365 ◽

2021 ◽

Author(s):

Thackery I. Brown ◽

Qiliang He ◽

Irem Aselcioglu ◽

Chantal E. Stern

Keyword(s):

Medial Temporal Lobes ◽

Temporal Lobes

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Structural Changes in Thalamic Nuclei Across Prodromal and Clinical Alzheimer’s Disease

Journal of Alzheimer s Disease ◽

10.3233/jad-201583 ◽

2021 ◽

pp. 1-11

Author(s):

Adam S. Bernstein ◽

Steven Z. Rapcsak ◽

Michael Hornberger ◽

Manojkumar Saranathan ◽

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Large Scale ◽

Structural Changes ◽

Thalamic Nuclei ◽

Medial Temporal Lobes ◽

Cognitive Changes ◽

Temporal Lobes ◽

Medial Geniculate ◽

Healthy Control

Background: Increasing evidence suggests that thalamic nuclei may atrophy in Alzheimer’s disease (AD). We hypothesized that there will be significant atrophy of limbic thalamic nuclei associated with declining memory and cognition across the AD continuum. Objective: The objective of this work was to characterize volume differences in thalamic nuclei in subjects with early and late mild cognitive impairment (MCI) as well as AD when compared to healthy control (HC) subjects using a novel MRI-based thalamic segmentation technique (THOMAS). Methods: MPRAGE data from the ADNI database were used in this study (n = 540). Healthy control (n = 125), early MCI (n = 212), late MCI (n = 114), and AD subjects (n = 89) were selected, and their MRI data were parcellated to determine the volumes of 11 thalamic nuclei for each subject. Volumes across the different clinical subgroups were compared using ANCOVA. Results: There were significant differences in thalamic nuclei volumes between HC, late MCI, and AD subjects. The anteroventral, mediodorsal, pulvinar, medial geniculate, and centromedian nuclei were significantly smaller in subjects with late MCI and AD when compared to HC subjects. Furthermore, the mediodorsal, pulvinar, and medial geniculate nuclei were significantly smaller in early MCI when compared to HC subjects. Conclusion: This work highlights nucleus specific atrophy within the thalamus in subjects with early and late MCI and AD. This is consistent with the hypothesis that memory and cognitive changes in AD are mediated by damage to a large-scale integrated neural network that extends beyond the medial temporal lobes.

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White Matter Integrity Predicts Delay Discounting Behavior in 9- to 23-Year-Olds: A Diffusion Tensor Imaging Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2009.21107 ◽

2009 ◽

Vol 21 (7) ◽

pp. 1406-1421 ◽

Cited By ~ 119

Author(s):

Elizabeth A. Olson ◽

Paul F. Collins ◽

Catalina J. Hooper ◽

Ryan Muetzel ◽

Kelvin O. Lim ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Delay Discounting ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Imaging Study ◽

Temporal Lobes ◽

Brain White Matter ◽

Independent Effects ◽

Age Range

Healthy participants (n = 79), ages 9–23, completed a delay discounting task assessing the extent to which the value of a monetary reward declines as the delay to its receipt increases. Diffusion tensor imaging (DTI) was used to evaluate how individual differences in delay discounting relate to variation in fractional anisotropy (FA) and mean diffusivity (MD) within whole-brain white matter using voxel-based regressions. Given that rapid prefrontal lobe development is occurring during this age range and that functional imaging studies have implicated the prefrontal cortex in discounting behavior, we hypothesized that differences in FA and MD would be associated with alterations in the discounting rate. The analyses revealed a number of clusters where less impulsive performance on the delay discounting task was associated with higher FA and lower MD. The clusters were located primarily in bilateral frontal and temporal lobes and were localized within white matter tracts, including portions of the inferior and superior longitudinal fasciculi, anterior thalamic radiation, uncinate fasciculus, inferior fronto-occipital fasciculus, corticospinal tract, and splenium of the corpus callosum. FA increased and MD decreased with age in the majority of these regions. Some, but not all, of the discounting/DTI associations remained significant after controlling for age. Findings are discussed in terms of both developmental and age-independent effects of white matter organization on discounting behavior.

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Exceptional Experiences Following Exposure to a Sham “God Helmet”: Evidence for Placebo, Individual Difference, and Time of Day Influences

Imagination Cognition and Personality ◽

10.1177/0276236617749185 ◽

2017 ◽

Vol 39 (1) ◽

pp. 44-87 ◽

Cited By ~ 1

Author(s):

Christine Simmonds-Moore ◽

Donadrian L. Rice ◽

Chase O’Gwin ◽

Ron Hopkins

Keyword(s):

Mixed Model ◽

Time Of Day ◽

Neural Stimulation ◽

Analysis Of Covariance ◽

Subjective Experiences ◽

Mixed Model Analysis ◽

Temporal Lobes ◽

Coding Scheme ◽

Paranormal Belief ◽

Inductive Thematic Analysis

It has been claimed that applying weak complex electromagnetic patterns to the temporal lobes in a “God Helmet” stimulates the intrusion of right-hemispheric processes to awareness, resulting in exceptional experiences (ExEs). We explored the roles of wearing a sham helmet, time of day, and individual differences (paranormal belief, synesthesia, locus of control, hyperesthesia, and prior anomalous experiences) in alterations in consciousness and ExEs in the absence of neural stimulation. Thirty-two skeptics and 35 paranormal believers completed baseline, sham (morning), and sham (afternoon) conditions. Participants relaxed in a Faraday chamber for 30 minutes. Exit interviews explored subjective experiences and participants completed the Phenomenology of Consciousness Inventory (PCI). A mixed-model analysis of covariance found that believers scored higher than skeptics on some PCI dimensions, there was no influence of study conditions on PCI scores, and there was no interaction between belief and study conditions. An inductive thematic analysis identified a coding scheme for ExE. Believers reported more ExEs than skeptics. Regression models supported roles for hyperesthesia in alterations in consciousness and synesthesia in ExEs.

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