Karl D Lerud

University of Connecticut | UConn · Department of Psychology

Computational models are used to predict the performance of human listeners for carefully specified signal and noise conditions. However, there may be substantial discrepancies between the conditions under which listeners are tested and those used for model predictions. Thus, models may predict better performance than exhibited by the listeners, or...

Pitch is a perceptual rather than physical phenomenon, important for spoken language use, musical communication, and other aspects of everyday life. Auditory stimuli can be designed to probe the relationship between perception and physiological responses to pitch-evoking stimuli. One technique for measuring physiological responses to pitch-evoking...

Non-invasive transcranial direct current stimulation (tDCS) can modulate activity of targeted brain regions. Whether tDCS can reliably and repeatedly modulate intrinsic connectivity of entire brain networks is unclear. We used concurrent tDCS-MRI to investigate the effect of high dose anodal tDCS on resting state connectivity within the Arcuate Fas...

We used three dose levels (Sham, 2mA, and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial...

Previous studies have shown that transcranial direct current stimulation (tDCS) can affect performance by decreasing regional excitability in a brain region that contributes to the task of interest. To our knowledge, no research to date has found both enhancing and diminishing effects on performance, depending upon which polarity of the current is...

We used three dose levels (Sham, 2mA, and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial...

Previous studies have shown that transcranial direct current stimulation (tDCS) can affect performance by decreasing regional excitability in a brain region that contributes to the task of interest. To our knowledge, no research to date has found both enhancing and diminishing effects on performance, depending upon which polarity of current is appl...

Non-invasive electrical stimulation can modulate not only targeted local intrinsic brain activity, but also activity in remote, yet connected brain regions. Such modulation of connected regions and/or entire networks may account for some of the treatment-induced changes in complex behaviors and cognitive processes. The current study tested whether...

Stroke is a leading cause of disability, most commonly with motor deficit. The motor recovery is associated with the structural and/or functional degree of injury to descending motor pathways. Additionally, neuroplasticity contributes to the recovery by unmasking pre-existing connections, establishing new synaptic contacts, reorganizing peri-lesion...

A novel electrode placement strategy for transcranial direct current stimulation method is explored to stimulate nodal cortical endpoints of the arcuate fasciculus. The poster discusses the preliminary results of this study

Pitch is a perceptual rather than physical phenomenon, important for spoken language use, musical communication, and other aspects of everyday life. Auditory stimuli can be designed to probe the relationship between perception and physiological responses to pitch-evoking stimuli. One technique for measuring physiological responses to pitch-evoking...

Nonlinear responses to acoustic signals arise through active processes in the cochlea, which has an exquisite sensitivity and wide dynamic range that can be explained by critical nonlinear oscillations of outer hair cells. Here we ask how the interaction of critical nonlinearities with the basilar membrane and other organ of Corti components could...

Hoglund (et al., 2010) reported the ability of listeners to detect a recorded signal masked by nine different ambient sounds. Signals were selected from 410 recordings of two different helicopters; maskers were selected from nine outdoor field recordings from three different locations. Signal and masker levels were randomized from trial to trial in...

Data show that amplitude modulation is an important factor in the neural representation and perceived pitch of sound. However, sounds with identical Hilbert envelopes can elicit different pitches. Sounds with consecutive harmonics elicit a pitch at the difference frequency of the harmonics. If this complex is shifted up or down, the amplitude envel...