Medical Sciences Commons^™

Perceptual Fluency Can Be Used As A Cue For Categorization Decisions., Sarah J Miles, John Paul Minda

Brain and Mind Institute Researchers' Publications

Learning in the prototype distortion task is thought to involve perceptual learning in which category members experience an enhanced visual response (Ashby & Maddox. Annual Review of Psychology, 56, 149-178, 2005). This response likely leads to more-efficient processing, which in turn may result in a feeling of perceptual fluency for category members. We examined the perceptual-fluency hypothesis by manipulating fluency independently from category membership. We predicted that when perceptual fluency was induced using subliminal priming, this fluency would be misattributed to category membership and would affect categorization decisions. In a prototype distortion task, the participants were more likely to judge …

Behavioral And Fmri Evidence That Cognitive Ability Modulates The Effect Of Semantic Context On Speech Intelligibility, Adriana A Zekveld, Mary Rudner, Ingrid Johnsrude, Dirk J Heslenfeld, Jerker Rönnberg

Brain and Mind Institute Researchers' Publications

Text cues facilitate the perception of spoken sentences to which they are semantically related (Zekveld, Rudner, et al., 2011). In this study, semantically related and unrelated cues preceding sentences evoked more activation in middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) than nonword cues, regardless of acoustic quality (speech in noise or speech in quiet). Larger verbal working memory (WM) capacity (reading span) was associated with greater intelligibility benefit obtained from related cues, with less speech-related activation in the left superior temporal gyrus and left anterior IFG, and with more activation in right medial frontal cortex for related versus …

Overexpression Of A Novel Cell Cycle Regulator Ecdysoneless In Breast Cancer: A Marker Of Poor Prognosis In Her2/Neu-Overexpressing Breast Cancer Patients., Xiangshan Zhao, Sameer Mirza, Alaa Alshareeda, Ying Zhang, Channabasavaiah B. Gurumurthy, Aditya Bele, Jun Hyun Kim, Shakur Mohibi, Monica Goswami, Subodh M. Lele, William West, Fang Qiu, Ian O. Ellis, Emad A. Rakha, Andrew R. Green, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Uncontrolled proliferation is one of the hallmarks of breast cancer. We have previously identified the human Ecd protein (human ortholog of Drosophila Ecdysoneless, hereafter called Ecd) as a novel promoter of mammalian cell cycle progression, a function related to its ability to remove the repressive effects of Rb-family tumor suppressors on E2F transcription factors. Given the frequent dysregulation of cell cycle regulatory components in human cancer, we used immunohistochemistry of paraffin-embedded tissues to examine Ecd expression in normal breast tissue versus tissues representing increasing breast cancer progression. Initial studies of a smaller cohort without outcomes information showed that Ecd expression …

Greater Benefits Of Multisensory Integration During Complex Sensorimotor Transformations., Verena N Buchholz, Samanthi C Goonetilleke, W Pieter Medendorp, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Multisensory integration enables rapid and accurate behavior. To orient in space, sensory information registered initially in different reference frames has to be integrated with the current postural information to produce an appropriate motor response. In some postures, multisensory integration requires convergence of sensory evidence across hemispheres, which would presumably lessen or hinder integration. Here, we examined orienting gaze shifts in humans to visual, tactile, or visuotactile stimuli when the hands were either in a default uncrossed posture or a crossed posture requiring convergence across hemispheres. Surprisingly, we observed the greatest benefits of multisensory integration in the crossed posture, as indexed …

Encoding Of Sensory Prediction Errors In The Human Cerebellum., John Schlerf, Richard B Ivry, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

A central tenet of motor neuroscience is that the cerebellum learns from sensory prediction errors. Surprisingly, neuroimaging studies have not revealed definitive signatures of error processing in the cerebellum. Furthermore, neurophysiologic studies suggest an asymmetry, such that the cerebellum may encode errors arising from unexpected sensory events, but not errors reflecting the omission of expected stimuli. We conducted an imaging study to compare the cerebellar response to these two types of errors. Participants made fast out-and-back reaching movements, aiming either for an object that delivered a force pulse if intersected or for a gap between two objects, either of which …

Rapid Perceptual Learning Of Noise-Vocoded Speech Requires Attention, Julia Jones Huyck, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

Humans are able to adapt to unfamiliar forms of speech (such as accented, time-compressed, or noise-vocoded speech) quite rapidly. Can such perceptual learning occur when attention is directed away from the speech signal? Here, participants were simultaneously exposed to noise-vocoded sentences, auditory distractors, and visual distractors. One group attended to the speech, listening to each sentence and reporting what they heard. Two other groups attended to either the auditory or visual distractors, performing a target-detection task. Only the attend-speech group benefited from the exposure when subsequently reporting noise-vocoded sentences. Thus, attention to noise-vocoded speech appears necessary for learning.

Discriminating Famous From Fictional Names Based On Lifetime Experience: Evidence In Support Of A Signal-Detection Model Based On Finite Mixture Distributions., Ben Bowles, Iain M Harlow, Melissa M Meeking, Stefan Köhler

Brain and Mind Institute Researchers' Publications

It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection mechanism contributes to discriminations between moderately famous and fictional names based on lifetime experience. Unique to fame judgments is a lack of control over participants' previous exposure to the stimuli deemed "targets" by the experimenter; specifically, if they pertain to moderately famous individuals, participants may have had no prior exposure to a substantial proportion of the …

A 2-Step Approach To Myeloablative Haploidentical Stem Cell Transplantation: A Phase 1/2 Trial Performed With Optimized T-Cell Dosing., Dolores Gross, Matthew Carabasi, Joanne Filicko-O'Hara, Margaret Kasner, John L Wagner, Beth Colombe, Patricia Cornett Farley, William O'Hara, Phyllis Flomenberg, Maria Werner-Wasik, Janet Brunner, Bijoyesh Mookerjee, Terry Hyslop, Mark Weiss, Neal Flomenberg

Department of Medical Oncology Faculty Papers

Studies of haploidentical hematopoietic stem cell transplantation (HSCT) have identified threshold doses of T cells below which severe GVHD is usually absent. However, little is known regarding optimal T-cell dosing as it relates to engraftment, immune reconstitution, and relapse. To begin to address this question, we developed a 2-step myeloablative approach to haploidentical HSCT in which 27 patients conditioned with total body irradiation (TBI) were given a fixed dose of donor T cells (HSCT step 1), followed by cyclophosphamide (CY) for T-cell tolerization. A CD34-selected HSC product (HSCT step 2) was infused after CY. A dose of 2 × 10(8)/kg …

Multiple Mechanisms Of Consciousness: The Neural Correlates Of Emotional Awareness., Jayna M Amting, Steven G Greening, Derek G V Mitchell

Brain and Mind Institute Researchers' Publications

Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, …

The Risks And Benefits Of Long-Term Use Of Hydroxyurea In Sickle Cell Anemia: A 17.5 Year Follow-Up., M. H. Steinberg, W. F. Mccarthy, O. Castro, S. K. Ballas, F. D. Armstrong, W. Smith, K. Ataga, P. Swerdlow, A. Kutlar, L. Decastro, M. A. Waclawiw, E. Orringer, S. Jones, D. Strayhorn, W. Rosse, G. Phillips, D. Pearce, A. Johnson-Telfair, L. Daitch, P. Milner, A. Tracy, S. Valdez, G. E. Allen, J. Moshang, B. Scott, C. Bigelow, A. Anderson, V. Sabahi, T. Harrington, W. Labrousse, C. Pegelow, D. Temple, E. Case, R. Harrell, S. Childerie, S. Embury, B. Schmidt, D. Davies, Y. Saunthararajah, M. Koshy, N. Talischy-Zahed, L. Dorn, G. Pendarvis, M. Mcgee, M. Telfer, A. Davis, O. C. Onyekwere, C. Nwokolo, H. Finke, E. Perlin, J. Siteman, M. Bryan, T. Saunders, Y. Barber, P. Gascon, P. Di Paolo, S. Gargiulo, J. Eckman, E. Carter-Randall, J. H. Bailey, A. Platt, L. Waller, G. Ramirez, V. Knors, S. Hernandez, E. M. Rodriguez, E. Wilkes, E. Vichinsky, W. Hagar, C. Hoehner, E. Hackney-Stevens, S. Claster, A. Earles, K. Kleman, K. Mclaughlin, L. White, B. Maddox, L. Usry, A. Brenner, K. Williams, R. O'Brien, K. Genther, S. Shurin, B. Berman, K. Chiarucci, L. Keverline, N. Olivieri, J. Chow, M. Hui, D. Shaw, N. Lewis, M. Okam, E. Mandell, A. Palmer, K. Bridges, B. Tynan, C. Winograd, R. Bellevue, H. Dosik, M. Sheikhai, P. Ryans, H. Souffrant, B. Adler, A. Johnson-Telfair, L. Eskridge, J. Prchal, J. Braddock, T. Mcardle, T. Carlos, A. Roundtree-Schmotzer, D. Gardner

Department of Medicine Faculty Papers

A randomized, controlled clinical trial established the efficacy and safety of short-term use of hydroxyurea in adult sickle cell anemia. To examine the risks and benefits of long-term hydroxyurea usage, patients in this trial were followed for 17.5 years during which they could start or stop hydroxyurea. The purpose of this follow-up was to search for adverse outcomes and estimate mortality. For each outcome and for mortality, exact 95% confidence intervals were calculated, or tests were conducted at alpha = 0.05 level (P-value <0.05 for statistical significance). Although the death rate in the overall study cohort was high (43.1%; 4.4 per 100 person-years), mortality was reduced in individuals with long-term exposure to hydroxyurea. Survival curves demonstrated a significant reduction in deaths with long-term exposure. Twenty-four percent of deaths were due to pulmonary complications; 87.1% occurred in patients who never took hydroxyurea or took it for <5 years. Stroke, organ dysfunction, infection, and malignancy were similar in all groups. Our results, while no longer the product of a randomized study because of the ethical concerns of withholding an efficacious treatment, suggest that long-term use of hydroxyurea is safe and might decrease mortality.

Intracranial Eeg Reveals A Time- And Frequency-Specific Role For The Right Inferior Frontal Gyrus And Primary Motor Cortex In Stopping Initiated Responses, Nicole Swann, Nitin Tandon, Ryan Canolty, Timothy M Ellmore, Linda K Mcevoy, Stephen Dreyer, Michael Disano, Adam R Aron

Faculty, Staff and Student Publications

Inappropriate response tendencies may be stopped via a specific fronto/basal ganglia/primary motor cortical network. We sought to characterize the functional role of two regions in this putative stopping network, the right inferior frontal gyrus (IFG) and the primary motor cortex (M1), using electocorticography from subdural electrodes in four patients while they performed a stop-signal task. On each trial, a motor response was initiated, and on a minority of trials a stop signal instructed the patient to try to stop the response. For each patient, there was a greater right IFG response in the beta frequency band ( approximately 16 Hz) …

Adapting To Dynamic Stimulus-Response Values: Differential Contributions Of Inferior Frontal, Dorsomedial, And Dorsolateral Regions Of Prefrontal Cortex To Decision Making., Derek G V Mitchell, Qian Luo, Shelley B Avny, Tomasz Kasprzycki, Karanvir Gupta, Gang Chen, Elizabeth C Finger, R James R Blair

Brain and Mind Institute Researchers' Publications

Dorsomedial prefrontal cortex (dmPFC), dorsolateral prefrontal cortex (dlPFC), and inferior frontal gyrus (IFG) have all been implicated in resolving decision conflict whether this conflict is generated by having to select between responses of similar value or by making selections following a reversal in reinforcement contingencies. However, work distinguishing their individual functional contributions remains preliminary. We used functional magnetic resonance imaging to delineate the functional role of these systems with regard to both forms of decision conflict. Within dmPFC and dlPFC, blood oxygen level-dependent responses increased in response to decision conflict regardless of whether the conflict occurred in the context of …

Perirhinal Cortex Contributes To Accuracy In Recognition Memory And Perceptual Discriminations., Edward B O'Neil, Anthony D Cate, Stefan Köhler

Brain and Mind Institute Researchers' Publications

The prevailing view of the medial temporal lobe (MTL) holds that its structures are dedicated to long-term declarative memory. Recent evidence challenges this position, suggesting that perirhinal cortex (PRc) in the MTL may also play a role in perceptual discriminations of stimuli with substantial visual feature overlap. Relevant neuropsychological findings in humans have been inconclusive, likely because studies have relied on patients with large and variable MTL lesions. Here, we conducted a functional magnetic resonance imaging study in healthy individuals to determine whether PRc shows a performance-related involvement in perceptual oddball judgments that is comparable to its established role in …

Searching For The Majority: Algorithms Of Voluntary Control, Jin Fan, Kevin G. Guise, Xun Liu, Hongbin Wang

Faculty, Staff and Student Publications

Voluntary control of information processing is crucial to allocate resources and prioritize the processes that are most important under a given situation; the algorithms underlying such control, however, are often not clear. We investigated possible algorithms of control for the performance of the majority function, in which participants searched for and identified one of two alternative categories (left or right pointing arrows) as composing the majority in each stimulus set. We manipulated the amount (set size of 1, 3, and 5) and content (ratio of left and right pointing arrows within a set) of the inputs to test competing hypotheses …

Concave Pit-Containing Scaffold Surfaces Improve Stem Cell-Derived Osteoblast Performance And Lead To Significant Bone Tissue Formation., Antonio Graziano, Riccardo D'Aquino, Maria Gabriella Cusella-De Angelis, Gregorio Laino, Adriano Piattelli, Maurizio Pacifici, Alfredo De Rosa, Gianpaolo Papaccio

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear.

METHODOLOGY AND FINDINGS: In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA) scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone) to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i) large microcavities of 80-120 microm in diameter and 40-100 microm in depth, which we termed primary; and (ii) smaller microcavities of 10-20 microm in diameter …