Biology subjects

Feinberg, D.

Publications and source records attributed to Feinberg, D..

5 recordsLinked to original sources

bioRxiv2026

Peripheral Nerve Stimulation Optimized Pulses for EPI (POPE) allows high-resolution fMRI

PurposeRecent improvements in MRI gradient design and amplifiers, advanced MRI scanners are now routinely utilizing slew rates of several hundred T/m/s. However, full gradient performance cannot be exploited in high-resolution EPI due to peripheral nerve stimulation (PNS) limits. We aim to characterize and mitigate these PNS constraints using a simple sequence modification: PNS-optimized EPI gradient pulse shapes. MethodsPNS-Optimized Pulses for EPI (POPE): we selectively reduce the slew rate of gradient pulses at periods of high predicted PNS spikes, while leaving the rest of the waveform unchanged. PNS sensation was evaluated. ResultsPOPE allows 7%-35% faster imaging of EPI protocols resolutions of 1mm-0.3mm resolutions without exceeding predicted PNS. With such improvements, POPE allows robust 0.3 mm isotropic fMRI protocols that would have exceeded safety limits without it. ConclusionPOPE facilitates locally precise fMRI activation mapping on clinical 7T scanners at spatial resolution that were previously unattainable due to PNS limitations.

neuroscience↗

bioRxiv2026

Multiphasic myelination and dendritic growth modulate qMRI signals in human visual cortex.

How does myelin develop in human visual cortex? By combining immunohistochemistry with in vivo and postmortem magnetic resonance imaging of longitudinal relaxation rate (R1), which increases with myelin content, we find that myelin and R1 increase across development but follow distinct trajectories. Immunohistochemistry reveals two phases of myelination: an infant phase of limited oligodendrogenesis, with myelin restricted to deep cortical layers, followed by widespread myelination across all layers during childhood. Cortical R1 also increases across development and correlates with myelin by childhood. However, in infancy, R1 increases outpace myelin growth and instead tracks dendritic arborization, indicating that the microstructural drivers of R1 change across development. We hypothesize that deep layer myelination in infancy contributes to early visual function whereas later myelination of superficial layers enables prolonged cortical plasticity and learning of complex visual behaviors.

neuroscience↗

bioRxiv2024

Fuzzy ripple artifact in high resolution fMRI: identification, cause, and mitigation

PurposeHigh resolution fMRI is a rapidly growing research field focused on capturing functional signal changes across cortical layers. However, the data acquisition is limited by low spatial frequency EPI artifacts; termed here as Fuzzy Ripples. These artifacts limit the practical applicability of acquisition protocols with higher spatial resolution, faster acquisition speed, and they challenge imaging in lower brain areas. MethodsWe characterize Fuzzy Ripple artifacts across commonly used sequences and distinguish them from conventional EPI Nyquist ghosts, off-resonance effects, and GRAPPA artifacts. To investigate their origin, we employ dual polarity readouts. ResultsOur findings indicate that Fuzzy Ripples are primarily caused by readout-specific imperfections in k-space trajectories, which can be exacerbated by inductive coupling between third-order shims and readout gradients. We also find that these artifacts can be mitigated through complex-valued averaging of dual polarity EPI or by disconnecting the third-order shim coils. ConclusionThe proposed mitigation strategies allow overcoming current limitations in layer-fMRI protocols: O_LIAchieving resolutions beyond 0.8mm is feasible, and even at 3T, we achieved 0.53mm voxel functional connectivity mapping. C_LIO_LISub-millimeter sampling acceleration can be increased to allow sub-second TRs and laminar whole brain protocols with up to GRAPPA 8. C_LIO_LISub-millimeter fMRI is achievable in lower brain areas, including the cerebellum. C_LI

neuroscience↗

bioRxiv2018

Does the strength of women’s attraction to male vocal masculinity track changes in steroid hormones?

Recent studies that either used luteinizing hormone tests to confirm the timing of ovulation or measured steroid hormones from saliva have found little evidence that womens preferences for facial or body masculinity track within-subject changes in womens fertility or hormonal status. Fewer studies using these methods have examined womens preferences for vocal masculinity, however, and those that did report mixed results. Consequently, we used a longitudinal design and measured steroid hormones from saliva to test for evidence of hormonal regulation of womens (N=351) preferences for two aspects of male vocal masculinity (low pitch and low formants). Analyses suggested that preferences for masculine pitch, but not masculine formants, may track within-woman changes in estradiol. Although these results present some evidence for the hypothesis that within-subject hormones regulate womens attraction to masculine men, we do not discount the possibility that the effect of estradiol on pitch preferences in the current study is a false positive.

animal behavior and cognition↗

bioRxiv2017

No evidence for correlations between handgrip strength and sexually dimorphic acoustic properties of voices

ObjectivesRecent research on the signal value of masculine physical characteristics in men has focused on the possibility that such characteristics are valid cues of physical strength. However, evidence that sexually dimorphic vocal characteristics are correlated with physical strength is equivocal. Consequently, we undertook a further test for possible relationships between physical strength and masculine vocal characteristics.\n\nMethodsWe tested the putative relationships between White UK (N=115) and Chinese (N=106) participants handgrip strength (a widely used proxy for general upper-body strength) and five sexually dimorphic acoustic properties of voices: fundamental frequency (F0), fundamental frequencys standard deviation (F0-SD), formant dispersion (Df), formant position (Pf), and estimated vocal-tract length (VTL).\n\nResultsAnalyses revealed no clear evidence that stronger individuals had more masculine voices.\n\nConclusionsOur results do not support the hypothesis that masculine vocal characteristics are a valid cue of physical strength.

evolutionary biology↗