Neural plasticity expressed in central auditory structures with and without tinnitus

Sensory training therapies for tinnitus are based on the assumption that, notwithstanding neural changes related to tinnitus, auditory training can alter the response properties of neurons in auditory pathways. To assess this assumption, we investigated whether brain changes induced by sensory training in tinnitus sufferers and measured by electroencephalography (EEG) are similar to those induced in age and hearing loss matched individuals without tinnitus trained on the same auditory task. Auditory training was given using a 5 kHz 40-Hz amplitude-modulated (AM) sound that was in the tinnitus frequency region of the tinnitus subjects and enabled extraction of the 40-Hz auditory steady-state response (ASSR) and P2 transient response known to localize to primary and non-primary auditory cortex, respectively. P2 amplitude increased over training sessions equally in participants with tinnitus and in control subjects, suggesting normal remodeling of non-primary auditory regions in tinnitus. However, training-induced changes in the ASSR differed between the tinnitus and control groups. In controls the phase delay between the 40-Hz response and stimulus waveforms reduced by about 10° over training, in agreement with previous results obtained in young normal hearing individuals. However, ASSR phase did not change significantly with training in the tinnitus group, although some participants showed phase shifts resembling controls. On the other hand, ASSR amplitude increased with training in the tinnitus group, whereas in controls this response (which is difficult to remodel in young normal hearing subjects) did not change with training. These results suggest that neural changes related to tinnitus altered how neural plasticity was expressed in the region of primary but not non-primary auditory cortex. Auditory training did not reduce tinnitus loudness although a small effect on the tinnitus spectrum was detected

The strain exerted by a vortex on a flame - Determined from velocityfield images

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77209/1/AIAA-1993-362-453.pd

A problem solving approach to visceral learning

Abstract only. Permission to include in repository granted by Sally Byers, Permissions Assistant, Wiley-Blackwell Publishing Ltd.An earlier paper in this series depicted visceral learning as a problem in concept identification in which subjects seek information about the visceral target (Roberts, Williams, Farrell, & Marlin. 1979). Concepts pertaining to this target are based initially upon procedural details of training and are modified as feedback identifies instances of the desired response. Evidence for this view was sought by examining verbal reports for the information about target responding that is presumably the product of a concept identification process. Accurate self-report was observed when subjects were successfully trained to produce either: 1) an increase and decrease in heart rate, or 2) lateralized changes (L > R and R> L) in skin conductance. Control of the response in the absence of accurate self-report was not observed in either training condition. The present paper describes an extended framework for the study of learning mechanisms. In this approach, a task statement is assumed to establish a problem space within which visceral learning proceeds. Major components of this space include: 1) a representation of task objectives. 2) initial concepts concerning effective strategies derived from the task statement and the subject's personal history, and 3) a processing system which is organized to acquire information about the response from feedback events. The processing system is seen as a construction which is determined uniquely for each learning procedure by processing requirements that are implicit in problem structure. The system organizes memory to receive information about the response and codes this information in a manner appropriate for production of the target in accordance with performance requirements of the task. This analysis suggested that within-subject training for two visceral targets with a transfer requirement (as in Roberts et al., 1979) might have favored identification of differences rather than similarities between the targets and encoding in a manner appropriate for recall without feedback as a retrieval cue. Consequently accurate self-report was assessed as a function of forewarning of transfer when subjects were trained to produce a single target alone. The purpose was to determine whether a problem-solving approach might identify processing conditions that favor veridical self-report following training on a feedback task. (Supported by A0132 from NSERC of Canada)Ye

An Active Matrix Flat Panel Dosimeter (AMFPD) for inâ phantom dosimetric measurements

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135086/1/mp5012.pd

Effect of volume reduction on lung transplant timing and selection for chronic obstructive pulmonary disease

AbstractBackground: End-stage chronic obstructive pulmonary disease has traditionally been treated with lung transplantation. For 2 years, our lung transplantation program has placed patients with appropriate criteria for lung transplantation and volume reduction into a prospective management algorithm. These patients are offered the lung volume reduction option as a “bridge” to “extend” the eventual time to transplantation. We examine the results of this pilot program. Methods: From October 11, 1993, to April 17, 1997, 31 patients were evaluated for lung transplantation who also had physiologic criteria for volume reduction (forced expiratory volume in 1 second ≤ 25%; residual volume > 200%; significant ventilation/perfusion heterogeneity). All patients completed 6 weeks of pulmonary rehabilitation and then had baseline pulmonary function and 6-minute walk tests. These patients were then offered volume reduction as a “bridge” and were simultaneously listed for transplantation. Postoperatively, these 31 patients were then divided into two groups: Those with satisfactory results at 4 to 6 months after volume reduction and those with unsatisfactory results. Volume reduction was performed through a video thoracic approach in 87% of the patients and bilateral median sternotomy in the remaining 13%. The condition of the patients was monitored after the operation with repeated pulmonary function tests and 6-minute walk tests at 3-month intervals. Results: Twenty-four of 31 patients (77.4%) had primary success (at 4 to 6 months) results after lung volume reduction and 7 patients (22.6%) had primary failure, including 1 patient who died in the perioperative period (3.2%). Four patients (16.7%) from the primary success cohort had significant deterioration in their pulmonary function during intermediate-term follow-up and were then reconsidered for lung transplantation. Two of them have subsequently undergone transplantation with good postoperative pulmonary function results. Interestingly, three patients had α1-antitrypsin deficiency; two had a poor outcome of lung volume reduction and primary failure. Conclusions: Lung volume reduction in these patients is safe. Seventy-seven percent of otherwise suitable candidates for lung transplantation achieved initial good results from volume reduction and were deactivated from the list (placed on status 7). Most patients entering our prospective management algorithm have either significantly delayed or completely avoided lung transplantation after volume reduction. Lung volume reduction has substantially affected the practice, timing, and selection of patients for lung transplantation. Our waiting list now has a reduced percentage of patients with a diagnosis of chronic obstructive pulmonary disease compared with 3 years ago. Our experience suggests that lung volume reduction may be limited as a “bridge” in α1-antitrypsin deficiency. (J Thorac Cardiovasc Surg 1998;115:9-18

Visceral learning as concept identification

Abstract only. Permission to include in repository granted by Sally Byers, Permissions Assistant, Wiley-Blackwell Publishing Ltd.Visceral learning may be depicted as a process in which subjects seek information about the behavioral goal. Concepts of this goal are based initially upon procedural details of training and are modified as feedback identifies instances of the target response. This approach was assessed by determining whether subjects were capable of describing activities associated with the visceral target after feedback training. Two groups were given visual feedback for changes in heart rate (HR) or lateralized skin conductance (LSC). The two visceral targets within each group (HR: inc/dec; LSC: L>R/R>L) were designated as Response A and Response B. Production of the response on A and B trials in the presence (Training) and absence (Transfer) of feedback was measured. After a one-hour session subjects were asked, without prior notification, to provide written reports describing what they did to control feedback on A and B trials. Awareness of the response was assessed by determining whether judges given the reports successfully identified the visceral target which was required on A and B trials for each subject. Awareness of activities related to feedback was also assessed by quantitative scales completed by the subjects after the written report. Awareness of the response was demonstrated on identification tasks for each experimental condition (HR and LSC). Furthermore, awareness (measured as probability ofcorrect identification) was significantly correlated with performance during Training and Transfer in the HR oroup, but this relationship was obtained only for Transfer in the LSC condition. Transfer without awareness was not observed in either group. Scale ratings did not differ between the visceral targets in either training condition. However, awareness was confirmed by significant correlations between these ratings and visceral performance for Training and Transfer in the HR group and for Transfer in the LSC group. These findings suggest that veridical concepts of the behavioral goal are formed during visceral learning. The concept-formation process appears important to Transfer but does not fully explain performance on feedback trials in the LSC experiment. (Supported by A0132 from NSERC of Canada)Ye

Establishment and characterization of MRT cell lines from genetically engineered mouse models and the influence of genetic background on their development

Malignant rhabdoid tumors (MRTs) are rare, aggressive cancers occuring in young children primarily through inactivation of the SNF5(INI1, SMARCB1) tumor suppressor gene. We and others have demonstrated that mice heterozygous for a Snf5 null allele develop MRTs with partial penetrance. We have also shown that Snf5+/− mice that lack expression of the pRb family, due to TgT121 transgene expression, develop MRTs with increased penetrance and decreased latency. Here, we report that altering the genetic background has substantial effects upon MRT development in Snf5+/− and TgT121;Snf5+/− mice, with a mixed F1 background resulting in increased latency and the appearance of brain tumors. We also report the establishment of the first mouse MRT cell lines that recapitulate many features of their human counterparts. Our studies provide further insight into the genetic influences on MRT development as well as provide valuable new cell culture and genetically engineered mouse models for the study of CNS-MRT etiology

Dependencies in language: On the causal ontology of linguistic systems

Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being made—usually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms

Dependencies in language: On the causal ontology of linguistic systems

Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being made—usually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms

Dependencies in language: On the causal ontology of linguistic systems

Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being made—usually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms