Digital Commons Network^™

Nonrigid Registration Of Three-Dimensional Ultrasound And Magnetic Resonance Images Of The Carotid Arteries, Nuwan D Nanayakkara, Bernard Chiu, Abbas Samani, J David Spence, Jagath Samarabandu, Grace Parraga, Aaron Fenster

Medical Biophysics Publications

Atherosclerosis at the carotid bifurcation can result in cerebral emboli, which in turn can block the blood supply to the brain causing ischemic strokes. Noninvasive imaging tools that better characterize arterial wall, and atherosclerotic plaque structure and composition may help to determine the factors which lead to the development of unstable lesions, and identify patients at risk of plaque disruption and stroke. Carotid magnetic resonance (MR) imaging allows for the characterization of carotid vessel wall and plaque composition, the characterization of normal and pathological arterial wall, the quantification of plaque size, and the detection of plaque integrity. On the other …

The Future (Or Lack Of Future) Of Personalized Prescription In Psychiatry, Jose De Leon

Psychiatry Faculty Publications

Rapid technological advances in genetics have created conceptual chaos regarding the genetics of drug response. Terms for differing concepts are used interchangeably: pharmacogenetics with pharmacogenomics, personalized medicine with personalized prescription. Biomarker has many definitions. The author prefers the concept of personalized prescription and uses it with implications beyond pharmacogenetics by considering all scientific information valid for prescribing medication. Genetics may not be crucial for all drugs. In this comprehensive view, clinicians must consider genetic, environmental and personal variables when prescribing medication and incorporate some basic pharmacological principles: (1) safety and efficacy, (2) pharmacokinetics and pharmacodynamics, (3) therapeutic window and prescriber's …

Multimodality Education For Airway Endoscopy Skill Development., Ellen S. Deutsch, Thomas Christenson, Joseph Curry, Jobayer Hossain, Karen Zur, Ian Jacobs

Department of Otolaryngology - Head and Neck Surgery Faculty Papers

OBJECTIVES: Airway endoscopy is a difficult skill to master. A unique practicum was designed to help otolaryngology residents develop endoscopy skills. The learning modalities included lectures, an animal laboratory, high-fidelity manikins, virtual bronchoscopy simulation, and standardized patients. This study compares the relative subjective value of these learning modalities for skill development and realism. METHODS: Participants used a Likert scale (1=disagree to 5=agree) and open responses to anonymously rate the efficacy of 5 learning modalities for teaching airway management, endoscopy skills, and clinical leadership and for providing a realistic experience. RESULTS: The results in 2007 were uniformly positive, with mean scores …

Cryptococcosis Of The Upper Genital Tract., Manish Gopal, Stacy Mccrosson, Pamela Edmonds, Thomas Klein

Department of Obstetrics and Gynecology Faculty Papers

Upper genital tract infection by Cryptococcus neoformans has not previously been reported. We describe such a case, in order to alert clinicians to the existence of this rare infection. A 34-year-old woman with AIDS presented with chronic menorrhagia, fever, anemia, and thrombocytopenia. Despite blood transfusions and hormonal therapy, her vaginal bleeding could not be controlled and she became hemodynamically unstable. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed, at which time granulomatous peritonitis and prominent myometrial blood vessels were found. Histologic examination revealed cryptococcal infection of all upper genital organs. This case demonstrates that disseminated cryptococcosis may involve the upper …

Multiple Independent Genetic Factors At Nos1ap Modulate The Qt Interval In A Multi-Ethnic Population, Dan E. Arking, Amit Khera, Chao Xing, W H Linda Kao, Wendy Post, Eric Boerwinkle, Aravinda Chakravarti

Faculty, Staff and Student Publications

Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples …

The Specificity Of The Search Template, Mary J. Bravo, Hany Farid

Dartmouth Scholarship

When searching for a target object, observers use an internal representation of the target's appearance as a search template. This study used naturalistic stimuli to examine the specificity of this template. Observers first learned several name-image pairs; they then participated in a search experiment in which the names served as cues and the images served as targets. To test whether the observers searched for the targets using an exact image template, we included targets that were transformations of the studied image and targets that belonged to the same subordinate-level category as the studied image. The same stimuli were also used …

Corr4a And Vrt325 Do Not Reduce The Inflammatory Response To P. Aeruginosa In Human Cystic Fibrosis Airway Epithelial Cells, Laleh Talebian, Bonita Coutermarsh, Jacqueline Y. Channon, Bruce A. Stanton

Dartmouth Scholarship

P. aeruginosa chronically colonizes the lung in CF patients and elicits a proinflammatory response. Excessive secretion of IL-6 and IL-8 by CF airway cells in response to P. aeruginosa infection in the CF airway is though to contribute to lung injury. Accordingly, the goal of this study was to test the hypothesis that Corr4a and VRT325, investigational compounds that increase ΔF508-CFTR mediated Cl⁻ secretion in human CF airway cells, reduce the pro-inflammatory response to P. aeruginosa.

The Sleeping Brain's Influence On Verbal Memory: Boosting Resistance To Interference, Jeffrey M. Ellenbogen, Justin C. Hulbert, Ying Jiang, Robert Stickgold

Dartmouth Scholarship

Memories evolve. After learning something new, the brain initiates a complex set of post-learning processing that facilitates recall (i.e., consolidation). Evidence points to sleep as one of the determinants of that change. But whenever a behavioral study of episodic memory shows a benefit of sleep, critics assert that sleep only leads to a temporary shelter from the damaging effects of interference that would otherwise accrue during wakefulness. To evaluate the potentially active role of sleep for verbal memory, we compared memory recall after sleep, with and without interference before testing. We demonstrated that recall performance for verbal memory was greater …

Iatrogenic Bile Duct Injury Associated With Anomalies Of The Right Hepatic Sectoral Ducts: A Misunderstood And Underappreciated Problem, Nitin Babel, Sujit Vijay Sakpal, Prakash Paragi, Jason Wellen, Stephen Feldman, Ronald Scott Chamberlain

Department of Surgery

Although laparoscopic cholecystectomy (LC) has been widely accepted as the standard of care, it continues to have a higher complication rate than open cholecystectomy. Bile duct injury with LC has often been attributed to surgical inexperience, but it is also clear that aberrant bile ducts are present in a significant number of patients who sustain biliary injuries during these procedures. We present three cases of right sectoral hepatic duct injuries which occurred during LC and provide a discussion of the conditions which are likely to lead to these injuries, as part of a strategy to prevent them.

Adaptive Radiation Therapy For Localized Mesothelioma With Mediastinal Metastasis Using Helical Tomotherapy., James Renaud, Slav Yartsev, A Rashid Dar, Jacob Van Dyk

Oncology Publications

The purpose of this study was to compare 2 adaptive radiotherapy strategies with helical tomotherapy. A patient having mesothelioma with mediastinal nodes was treated using helical tomotherapy with pretreatment megavoltage CT (MVCT) imaging. Gross tumor volumes (GTVs) were outlined on every MVCT study. Two alternatives for adapting the treatment were investigated: (1) keeping the prescribed dose to the targets while reducing the dose to the OARs and (2) escalating the target dose while maintaining the original level of healthy tissue sparing. Intensity modulated radiotherapy (step-and-shoot IMRT) and 3D conformal radiotherapy (3DCRT) plans for the patient were generated and compared. The …

Stat5 Regulation Of Bcl10 Parallels Constitutive Nfkappab Activation In Lymphoid Tumor Cells., Zsuzsanna S Nagy, Matthew J Lebaron, Jeremy A Ross, Abhisek Mitra, Hallgeir Rui, Robert A Kirken

Department of Cancer Biology Faculty Papers

BACKGROUND: Signal Transducer and Activator of Transcription 5 A and B (STAT5) are key survival factors in cells of the lymphoid lineage. Identification of novel, tissue-specific STAT5 regulated genes would advance the ability to combat diseases due to aberrant STAT5 signaling. In the present work a library of human STAT5 bound genomic elements was created and validated. RESULTS: Of several STAT5 responsive genomic regulatory elements identified, one was located within the first intron of the human BCL10 gene. Chromatin immuno-precipitation reactions confirmed constitutive in vivo STAT5 binding to this intronic fragment in various human lymphoid tumor cell lines. Interestingly, non-phosphorylated …

A Genome-Wide Association Study In Chronic Obstructive Pulmonary Disease (Copd): Identification Of Two Major Susceptibility Loci, Sreekumar G. Pillai, Dongliang Ge, Guohua Zhu, Xiangyang Kong, Kevin V. Shianna, Anna C. Need, Sheng Feng, Craig P. Hersh, Per Bakke, Amund Gulsvik, Andreas Ruppert, Karin C. Lødrup Carlsen, Allen Roses, Wayne Anderson, Stephen I. Rennard, David A. Lomas, Edwin K. Silverman, David B. Goldstein, Icgn Investigators

Journal Articles: Pulmonary & Critical Care Med

There is considerable variability in the susceptibility of smokers to develop chronic obstructive pulmonary disease (COPD). The only known genetic risk factor is severe deficiency of alpha(1)-antitrypsin, which is present in 1-2% of individuals with COPD. We conducted a genome-wide association study (GWAS) in a homogenous case-control cohort from Bergen, Norway (823 COPD cases and 810 smoking controls) and evaluated the top 100 single nucleotide polymorphisms (SNPs) in the family-based International COPD Genetics Network (ICGN; 1891 Caucasian individuals from 606 pedigrees) study. The polymorphisms that showed replication were further evaluated in 389 subjects from the US National Emphysema Treatment Trial …

Genetic And Hormonal Factors Modulate Spreading Depression And Transient Hemiparesis In Mouse Models Of Familial Hemiplegic Migraine Type 1, Katharina Eikermann-Haerter, Ergin Dileköz, Chiho Kudo, Sean I Savitz, Christian Waeber, Michael J Baum, Michel D Ferrari, Arn M J M Van Den Maagdenberg, Michael A Moskowitz, Cenk Ayata

Faculty, Staff and Student Publications

Familial hemiplegic migraine type 1 (FHM1) is an autosomal dominant subtype of migraine with aura that is associated with hemiparesis. As with other types of migraine, it affects women more frequently than men. FHM1 is caused by mutations in the CACNA1A gene, which encodes the alpha1A subunit of Cav2.1 channels; the R192Q mutation in CACNA1A causes a mild form of FHM1, whereas the S218L mutation causes a severe, often lethal phenotype. Spreading depression (SD), a slowly propagating neuronal and glial cell depolarization that leads to depression of neuronal activity, is the most likely cause of migraine aura. Here, we have …

Antibiotic Prophylaxis For Leptospirosis, David Brett-Major, Robert J. Lipnick

Journal Articles: Epidemiology

BACKGROUND: Leptospira infection is a global zoonosis with significant health impact for agricultural workers and those persons whose work or recreation takes them into endemic areas.

OBJECTIVES: This systematic review assessed the current literature for evidence for or against use of antibiotic prophylaxis against Leptospira infection (leptospirosis).

SEARCH STRATEGY: The authors searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and SCI-Expanded as well as relevant professional society meeting abstracts until January 2009.

SELECTION CRITERIA: Prospective, randomised clinical trials studying antibiotic prophylaxis against leptospirosis were selected.

DATA …

Improving Follow-Up Of Abnormal Cancer Screens Using Electronic Health Records: Trust But Verify Test Result Communication, Hardeep Singh, Lindsey Wilson, Laura A Petersen, Mona K Sawhney, Brian Reis, Donna Espadas, Dean F Sittig

Faculty, Staff and Student Publications

BACKGROUND: Early detection of colorectal cancer through timely follow-up of positive Fecal Occult Blood Tests (FOBTs) remains a challenge. In our previous work, we found 40% of positive FOBT results eligible for colonoscopy had no documented response by a treating clinician at two weeks despite procedures for electronic result notification. We determined if technical and/or workflow-related aspects of automated communication in the electronic health record could lead to the lack of response.

METHODS: Using both qualitative and quantitative methods, we evaluated positive FOBT communication in the electronic health record of a large, urban facility between May 2008 and March 2009. …

Activity Loss Is Associated With Cognitive Decline In Age-Related Macular Degeneration., Barry W. Rovner, Robin J. Casten, Benjamin E. Leiby, William S. Tasman

Department of Psychiatry and Human Behavior Faculty Papers

BACKGROUND/METHODS: The objective of this study was to determine whether relinquishing cognitive, physical, and social activities is associated with an increased risk of cognitive decline in patients with age-related macular degeneration (AMD). We conducted a 3-year longitudinal study of 206 nondemented patients with AMD.

RESULTS: Twenty-three subjects (14.4%) declined cognitively. Age, sex, education, decline in visual acuity, and number of dropped activities were associated with cognitive decline; each additional dropped activity increased the risk by 58%. Subjects who relinquished three activities were 3.87 times (95% confidence interval, 1.95-7.76) more likely to become demented than subjects who relinquished no activities; those …

Change In Refractive Status Of The Patients Undergoing Phacoemulsification Surgery., Mr Joshi, S Shakya

School of Health Professions

This study was carried out with the objective of finding refractive status of patients undergoing phacoemulsification surgery for cataract extraction. Success of cataract surgery can be quantified with the improvement in visual acuity with least amount of refractive error. Prospective study of 44 patients was done pre operatively and with subsequent follow up in the first, third and eighth week post operatively. Pre and post operative evaluation was carried out in terms of visual acuity, refractive error and corneal curvature. Among patients undergoing surgery, 91.0% achieved visual acuity of 6/9 or better at eighth week follow up 73.3% of patients …

The Root Of Dental Anatomy: A Case For Naming Eustachius The "Father Of Dental Anatomy"., Gregory W. Bennett

Journal Articles: College of Dentistry

When one considers the names of those whose affect on dentistry reached far beyond their lifetimes, one may think of Fauchard, Wells, Morton and Black. One name that deserves to be called among the pantheon of the greats is Bartholomaeus Eustachius. Eustachius was not the first to study the anatomy of the teeth and jaws, having been preceded by Da Vinci; however, he was the first to publish a treatise devoted entirely to this subject, Libellus de Dentibus, in 1563. As Sir William Osler, the father of modern medicine, stated: "In Science, the credit goes to the man who convinces …

Micrornas: Key Modulators Of Posttranscriptional Gene Expression., Steven P. O'Hara, Justin L. Mott, Patrick L. Splinter, Gregory J. Gores, Nicholas F. Larusso

Journal Articles: Biochemistry & Molecular Biology

No abstract provided.

Reduced Neutrophil Count In People Of African Descent Is Due To A Regulatory Variant In The Duffy Antigen Receptor For Chemokines Gene, David Reich, Michael A. Nalls, W H Linda Kao, Ermeg L. Akylbekova, Arti Tandon, Nick Patterson, James Mullikin, Wen-Chi Hsueh, Ching-Yu Cheng, Josef Coresh, Eric Boerwinkle, Man Li, Alicja Waliszewska, Julie Neubauer, Rongling Li, Tennille S. Leak, Lynette Ekunwe, Joe C. Files, Cheryl L. Hardy, Joseph M. Zmuda, Herman A. Taylor, Elad Ziv, Tamara B. Harris, James G. Wilson

Faculty, Staff and Student Publications

Persistently low white blood cell count (WBC) and neutrophil count is a well-described phenomenon in persons of African ancestry, whose etiology remains unknown. We recently used admixture mapping to identify an approximately 1-megabase region on chromosome 1, where ancestry status (African or European) almost entirely accounted for the difference in WBC between African Americans and European Americans. to identify the specific genetic change responsible for this association, we analyzed genotype and phenotype data from 6,005 African Americans from the Jackson Heart Study (JHS), the Health, Aging and Body Composition (Health ABC) Study, and the Atherosclerosis Risk in Communities (ARIC) Study. …

Intergenerational Wealth Transmission And The Dynamics Of Inequality In Small-Scale Societies, Monique Borgerhoff Mulder, Samuel Bowles, Tom Hertz, Adrian Bell, Jan Beise, Greg Clark, Ila Fazzio, Michael Gurven, Kim Hill, Paul L. Hooper, William Irons, Hillard Kaplan, Donna Leonetti, Bobbi Low, Frank Marlowe, Richard Mcelreath, Suresh Naidu, David Nolan, Patrizio Piraino, Robert Quinlan, Eric Schniter, Rebecca Sear, Mary Shenk, Eric Alden Smith, Christopher Von Reuden, Polly Wiessner

Psychology Faculty Articles and Research

Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population’s long-run steady-state level of inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. We estimate the degree of intergenerational transmission of three different types of wealth (material, embodied, and relational), as well as the extent of wealth inequality in 21 historical and contemporary populations. We show that intergenerational transmission of wealth and wealth inequality are substantial …

High-Resolution Analysis Of Dna Copy Number Alterations In Patients With Primary Open-Angle Glaucoma., Khaled K Abu-Amero, Ali Hellani, Patrick Bender, George L. Spaeth, Jonathan Myers, L Jay Katz, Marlene Moster, Thomas M Bosley

Wills Eye Hospital Papers

PURPOSE: To determine whether patients with isolated primary open-angle glaucoma (POAG) have evidence of chromosomal copy number alterations.

METHODS: Twenty-seven Caucasian and African-American POAG patients and 12 ethnically matched controls were carefully screened for possible glaucoma and tested for chromosomal copy number alterations using high resolution array comparative genomic hybridization.

RESULTS: No POAG patient had evidence of chromosomal copy number alterations when compared to normal ethnically matched controls. Additionally, there was no evidence of somatic mosaicism in any tested POAG patient.

CONCLUSIONS: Chromosomal deletions and/or duplications were not detected in POAG patients as compared to controls. Other chromosomal imbalances such …

Key Role Of T Cell Defects In Age-Related Vulnerability To West Nile Virus, James D. Brien, Jennifer L. Uhrlaub, Alec Hirsch, Clayton A. Wiley, Janko Nikolich-Zugich

Open Access Publications

West Nile virus (WNV) infection causes a life-threatening meningoencephalitis that becomes increasingly more prevalent over the age of 50 and is 40-50x more prevalent in people over the age of 70, compared with adults under the age of 40. In a mouse model of age-related vulnerability to WNV, we demonstrate that death correlates with increased viral titers in the brain and that this loss of virus control with age was the result of defects in the CD4 and CD8 T cell response against WNV. Specific age-related defects in T cell responses against dominant WNV epitopes were detected at the level …

Effector Memory T Cell Responses Are Associated With Protection Of Rhesus Monkeys From Mucosal Simian Immunodeficiency Virus Challenge., Scott G. Hansen, Cassandra Vieville, Nathan Whizin, Lia Coyne-Johnson, Don C. Siess, Derek D. Drummond, Alfred W. Legasse, Michael K. Axthelm, Kelli Oswald, Charles M. Trubey, Michael Piatak, Jeffrey D. Lifson, Jay A. Nelson, Michael A. Jarvis, Louis J. Picker

School of Biomedical Sciences

The rapid onset of massive, systemic viral replication during primary HIV or simian immunodeficiency virus (SIV) infection and the immune evasion capabilities of these viruses pose fundamental problems for vaccines that depend upon initial viral replication to stimulate effector T cell expansion and differentiation. We hypothesized that vaccines designed to maintain differentiated effector memory T cell (TEM cell) responses at viral entry sites might improve efficacy by impairing viral replication at its earliest stage, and we have therefore developed SIV protein-encoding vectors based on rhesus cytomegalovirus (RhCMV), the prototypical inducer of life-long TEM cell responses. RhCMV vectors expressing SIV Gag, …

Quality Improvement In Small Office Settings: An Examination Of Successful Practices., Daniel Wolfson, Elizabeth Bernabeo, Brian Leas, Shoshanna Sofaer, Gregory Pawlson, Donna Pillittere

College of Population Health Faculty Papers

BACKGROUND: Physicians in small to moderate primary care practices in the United States (U.S.) (<25>physicians) face unique challenges in implementing quality improvement (QI) initiatives, including limited resources, small staffs, and inadequate information technology systems 23,36. This qualitative study sought to identify and understand the characteristics and organizational cultures of physicians working in smaller practices who are actively engaged in measurement and quality improvement initiatives.

METHODS: We undertook a qualitative study, based on semi-structured, open-ended interviews conducted with practices (N = 39) that used performance data to drive quality improvement activities.

RESULTS: Physicians indicated that benefits to performing measurement and …

Quality Improvement In Small Office Settings: An Examination Of Successful Practices., Daniel Wolfson, Elizabeth Bernabeo, Brian Leas, Shoshanna Sofaer, Gregory Pawlson, Donna Pillittere

College of Population Health Faculty Papers

BACKGROUND: Physicians in small to moderate primary care practices in the United States (U.S.) (<25 >physicians) face unique challenges in implementing quality improvement (QI) initiatives, including limited resources, small staffs, and inadequate information technology systems 23,36. This qualitative study sought to identify and understand the characteristics and organizational cultures of physicians working in smaller practices who are actively engaged in measurement and quality improvement initiatives.

METHODS: We undertook a qualitative study, based on semi-structured, open-ended interviews conducted with practices (N = 39) that used performance data to drive quality improvement activities.

RESULTS: Physicians indicated that benefits to performing measurement and …

Eeg During Pedaling: Brain Activity During A Locomotion-Like Task In Humans, Sanket G. Jain

Master's Theses (2009 -)

This study characterized the brain electrical activity during pedaling, a locomotor-like task, in humans. We postulated that phasic brain activity would be associated with active pedaling, consistent with a cortical role in locomotor tasks. 64 channels of electroencephalogram (EEG) and 10 channels of electromyogram (EMG) data were recorded from 10 neurologically-intact volunteers while they performed active and passive (no effort) pedaling on a custom-designed stationary bicycle. Ensemble average waveforms, two dimensional topographic maps and amplitude of the beta (13-35 Hz) frequency band were analyzed and compared between active and passive trials. The absolute amplitude (peak positive-peak negative) of the EEG …

Regulation Of The Fibrosis And Angiogenesis Promoter Sparc/Osteonectin In Human Adipose Tissue By Weight Change, Leptin, Insulin, And Glucose., Katrina Kos, Steve Wong, Bee Tan, Anders Gummesson, Margareta Jernas, Niclas Franck, David Kerrigan, Fredrik H. Nystrom, Lena M.S. Carlsson, Harpal S. Randeva, Jonathan H. Pinkney, John P.H. Wilding

Peninsula Medical School

OBJECTIVE: Matricellular Secreted Protein, Acidic and Rich in Cysteine (SPARC), originally discovered in bone as osteonectin, is a mediator of collagen deposition and promotes fibrosis. Adipose tissue collagen has recently been found to be linked with metabolic dysregulation. Therefore, we tested the hypothesis that SPARC in human adipose tissue is influenced by glucose metabolism and adipokines. RESEARCH DESIGN AND METHODS: Serum and adipose tissue biopsies were obtained from morbidly obese nondiabetic subjects undergoing bariatric surgery and lean control subjects for analysis of metabolic markers, SPARC, and various cytokines (RT-PCR). Additionally, 24 obese subjects underwent a very-low-calorie diet of 1,883 kJ …

Cauda Equina Syndrome Following A Lumbar Puncture., Alexandra J. Sinclair, Camille Carroll, Brendan Davies

Peninsula Medical School

Lumbar puncture (LP), a common diagnostic procedure, is usually associated with low morbidity. We describe the case of a 29-year-old woman who underwent a non-traumatic LP in the setting of normal coagulation. Cauda equina syndrome subsequently developed secondary to an extradural spinal haematoma. Avoidance, identification and management of this uncommon complication are discussed. Iatrogenic cauda equina syndrome following LP is rare, but can cause significant morbidity. Our patient's experience and our review of the literature highlight that: (i) normal coagulation and a non-traumatic LP do not exclude this diagnostic possibility; (ii) early recognition determines the management and prognosis, as 50% …

What Determines Auditory Similarity? The Effect Of Stimulus Group And Methodology., Kirsteen M. Aldrich, Elizabeth J. Hellier, Judy Edworthy

School of Psychology

Two experiments on the internal representation of auditory stimuli compared the pairwise and grouping methodologies as means of deriving similarity judgements. A total of 45 undergraduate students participated in each experiment, judging the similarity of short auditory stimuli, using one of the methodologies. The experiments support and extend Bonebright's (1996) findings, using a further 60 stimuli. Results from both methodologies highlight the importance of category information and acoustic features, such as root mean square (RMS) power and pitch, in similarity judgements. Results showed that the grouping task is a viable alternative to the pairwise task with N > 20 sounds whilst …