Event-related potentials (ERPs) reflect the ongoing changes in EEG activity as a result of the brain’s response to various stimuli. ERPs are valuable tools for understanding the time course and nature of cognitive processes (e.g. attention or categorization) that occur before, during, and after the presentation of a stimulus. The N170 ERP component is emerging as a key neural indicator in psychology and associated disciplines. The N170 is characterized by a large negative deflection in the brain’s electrophysiological activity that occurs around 170 ms after a visual stimulus is presented, with a greater amplitude in response to faces in particular. Given its potential to grant insight into perhaps one of the most important stimuli in our species, the present study will investigate the N170 ERP face effect in a design that uses both upright and inverted faces. As the N170 is sensitive to the structural and configurational aspects of faces, it is anticipated that this will eventually allow for the distinction of how the brain perceives faces from non-face stimuli. Participants (N = 20) will passively view pictures of inverted and upright faces while being asked to mentally count rarely interspersed pictures of butterflies. It is predicted that a larger negative amplitude and longer latency for the N170 will be elicited for inverted faces compared to upright faces, consistent with the literature. These results will complement and improve the ongoing research that investigates the utility of the N170 ERP as a potential biomarker for face processing.

Following spinal cord injury (SCI) ascending and descending neural tracts between the brain and spinal cord can be disrupted, affecting sensory and motor function. However, if the injury occurs during early development, plasticity within the spinal cord allows for greater potential of recovery of motor function compared to adults with the same injury. Previous research with locomotor training paradigms suggests that routine treadmill training increases locomotor performance in animals with SCI. The purpose of this study was to examine hindlimb stepping behaviors following a neonatal SCI. A total of 40 rats were placed into four different groups (2 sexes x 2 surgery conditions). On postnatal day 1 (P1), male and female rats underwent a complete spinal cord transection (T8-T10) or a sham operation. Each rat received treadmill training from P10 through P17 for three ten-minute sessions per day. Video recordings were conducted on the last session of the first and final day. Treadmill steps were scored as unilateral or bilateral (coordination) and plantar, other, or mixed (foot posture)–with mixed being exclusive to bilateral stepping. This study will help identify how spinal circuitry and plasticity can support hindlimb stepping behaviors following an SCI. This research has clinical implications for physical and rehabilitative therapies which utilize use-dependent activity to harness neural plasticity and training to promote better sensory and motor function.

This study aims to delve further into the P300 wave which allows insight into the brain’s recognition and evaluation of the significance or unfamiliarity of a target stimulus, as well as the N170 event potential, which is essential and critical to understanding the perception and processing of human faces. The P300 is elicited in experimental situations that involve participants detecting infrequent target stimuli embedded within a series of more frequent non-target stimuli. Similarly, in the present study, the P300 is tested through the occasional images of butterfly stimuli while the frequent and more consistent non-target stimuli are facial images. The experiment is done in four separate blocks with individuals' faces ranging from four different races (White, Black, Hispanic/Latino, Asian) with a final fifth block of faces testing for own-age bias consisting of white younger and older adults. The P300 wave represents a higher cognitive function of information processing within the brain of the individual. By presenting when a certain, out-of-the-ordinary, stimulus is elicited the P300 effect allows for the understanding of cognitive information processing abnormalities Furthermore, we expect to identify the effect of inverted faces on facial perception and lastly, where the majority of emphasis on this paper lies, is the P300 oddball effect.

Auditory brainstem responses (ABRs) are used to objectively identify hearing loss across multiple frequencies in young children. Typically, brief tone-like sounds are used, but new “peaky speech” audiobook stimuli were created to facilitate faster testing by engaging toddlers who cannot nap, sit still, or participate in behavioral testing. Compensating for inner ear timing delays across frequencies of peaky speech (“CE-chirp-phase”) evoked more synchronous neural activity and larger ABRs compared to the original zero-phase speech, resulting in faster testing times. However, the timing of ABR waveforms suggested the CE-phase profile overcompensated the ear’s timing delays. Other delays, or phase profiles, may provide better synchrony in the inner ear and faster ABRs. Therefore, this study aimed to determine which chirp-phase profile produces the largest ABRs in the fastest recording time. Based on a pilot study, four chirp-phase profiles were chosen: CE, 2 level-dependent (60-dB and 65-dB), and a new peaky speech-based chirp. To date, 10 adults with normal hearing listened to 30 minutes of each chirp-profile while 2-channel ABRs were recorded. Overall, 60-dB chirps evoked the smallest ABRs, whereas the other three chirps evoked similarly sized ABRs with average signal-to-noise ratios (SNR) above a criterion 0-dB after 30 minutes. Four participants had all frequency-specific ABRs at 0-dB SNR within 22 minutes for the CE, peaky speech and 65-dB chirps. In summary, slightly different chirp profiles produce similar ABRs in reasonable recording times for some participants. Reducing testing time will be important for future audiobook-based ABR testing in toddlers.