Neurophysiology

The aim of this study was to further examine the relationship between anxiety, inhibitory control (IC), and brain functioning (electroencephalogram) in a critical age-range for social and emotional development (8-12-year-olds). Depression was a secondary focus but was included in the analyses given the common anxiety/depression overlap. Additionally, the participants (N = 42) were assigned to 4 weeks of either an emotional training program (Emotional gFocus), a neutral training program (Neutral gFocus), or a waitlisted control and were tested using cognitive, neurophysiological, and mood measures. Hierarchical regression models revealed that IC accuracy scores were significantly and negatively related to anxiety levels as indicated by the Screening For Child Anxiety Related Disorders (SCARED), as well as depression levels (using the Child Depression Inventory (CDI)), controlling for age and gender. Additionally, increased resting-state right lateral frontal alpha asymmetry was predictive of increased anxiety as well as depression levels. To evaluate the intervention effects, a series of Multivariate Analyses of Covariance (MANCOVA) and contrast tests were conducted to determine if group differences existed from pre-to-post for any of the measures of interest. Overall, the emotional and neutral training conditions showed similar reductions in anxiety and depression compared to the waitlist condition. Both the emotional and neutral conditions also facilitated significant improvements in IC accuracy compared to the control. Minimal pre-to-post power and asymmetry changes occurred in frontal and parietal regions; however, a lateral frontal leftward activity shift was found in the emotional training group. These findings further demonstrated a relationship between IC and anxiety and showed preliminary evidence that training IC has the potential to mitigate negative emotional functioning in adolescents. Future research is necessary to determine the importance of emotional training versus neutral as well as whether longer training intervals will be needed to facilitate a long-term impact.

Unlike most neurons in the adult nervous system, olfactory receptor neurons (ORN),
found in the olfactory epithelium (OE), continually turnover in the adult rat. These
neurons project their axons to the olfactory bulb which is their central target. The
present study eliminated target neurons in the bulb using N-methyl-D-aspartate
(NMDA) to examine the effects of target loss on ORN survival and maturation. We
compared the effects of the NMDA lesion to bulbectomy, a permanent surgical
removal of the bulb, which simultaneously causes damage to ORN axons. We found
that unlike bulbectomy, large numbers of dying OE cells were not observed at any
time after the lesion. The number of immature neurons increased relative to the
control side, and the number of mature neurons also slightly increased with time
following NMDA lesion. Survival of ORNs does not seem to be significantly altered
in the absence of its target.

The purpose of this study was to determine if resistance exercise altered
peripheral BDNF concentration. Eighteen trained male subjects were split into two
groups performing varied repetition ranges. DUP-HR and DUP-LR groups trained
3x/week for 8 weeks, and were equated for total volume (repetitions X sets X intensity).
Plasma BDNF and interleukin-6 (IL-6) levels were measured prior to and immediately
following the first exercise session of weeks 1, 2, 4 and 6. Pre-exercise levels were also
assessed prior to the second and third sessions of week 1 and 6. Lastly, resting levels
were measured before and after training intervention. No group differences (p>0.05) were detected for either biomarker. An acute BDNF elevation (p=0.018) was detected only in the final week of training. IL-6 elevations were detected at all acute measurements (p<0.01). BDNF and IL-6 percentage change correlated significantly (p<0.05) in week-1. No chronic alterations were observed (p>0.05).

Out of 60 million Americans suffering from sleep disorder, an estimated 18 million have sleep apnea. According to the U.S. Department of Health & Human Services, sleep apnea is a chronic condition that disrupts a patient’s sleep. While the annual cost of treating sleep apnea patients in the United States is approximately $3.18 billion (including screening costs) it is estimated that untreated sleep apnea may cause $3.4 billion in additional medical costs. A polysomnography (PSG) is an all-night sleep study which monitors various physical functions during sleep including electrical activity of the heart, brain wave patterns, eye movement, muscle tone, body movements, and breathing. It is currently, the most accurate and sophisticated test for the diagnosis of sleep-disordered breathing (SDB), but also, the most expensive. The cost of an overnight sleep study is estimated between $900 and $3,000. In addition, the PSG is not mobile and has to be administered outside a patient’s home. The Long QT Syndrome (LQTS) is a
rhythm disorder that causes erratic (unpredictable) heartbeats. The LQTS has been linked to patients with the most severe form of sleep apnea. If LQTS is left untreated, sudden
cardiac death may occur.

The perception of visual motion is an integral aspect of many organisms' engagement with the world. In this dissertation, a theory for the perception of visual object-motion is developed. Object-motion perception is distinguished from objectless-motion perception both experimentally and theoretically. A continuoustime dynamical neural model is developed in order to generalize the ndings and provide a theoretical framework for continued re nement of a theory for object-motion
perception. Theoretical implications as well as testable predictions of the model are discussed.

A delayed response paradigm was used to investigate the cerebral electroencephalographic (EEG) signal preceding bimanual finger flexions of continuously increasing and decreasing movement rates. The Bereitschaftspotential displayed larger amplitudes at faster required response rates as did two spectral frequency modes, which also showed magnitude reversals depending on the initiating finger. Furthermore, at these specific frequency modes, the averaged relative phase between electrode locations C3 and C4, as well as the variance in this measure was found to correspond closely to the variance in inter-response times derived from the subjects' movements. The results suggest the existence of possible signatures on the neurophysiological level which may yield information regarding the efficacy and parametric properties of the impending movement.

An array of four motion quartets (stimuli for which either horizontal or vertical motion is perceived depending on quartet aspect ratio) is arranged in a diamond configuration such that two global motion patterns are formed: (1) Rotation---alternating counterclockwise and clockwise motion is perceived, and (2) Parallel path motion---the perceived motions of all the elements are simultaneously horizontal or simultaneously vertical. The perception of rotation resulted in global feedback that biases the motion perceived for an individual component motion quartet to be more consistent with rotation than aspect ratio. Stronger rotation produced greater bias. Under certain conditions, the feedback-induced bias occurred even though global rotation was not perceived. The results were interpreted in the context of neurophysiological evidence regarding neurons in Areas MT and MSTd, and a dynamical theory of motion pattern formation (Hock, Schoner & Giese, 2003; Nichols, Hock & Schoner, 2006).