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1.
Urology ; 186: 101-106, 2024 04.
Article in English | MEDLINE | ID: mdl-38350551

ABSTRACT

OBJECTIVE: To review the management of ovarian cancer (OCa) associated hydronephrosis (HN). Specifically, we aim to identify optimal management of HN in the acute setting, predictors of HN resolution, and the role of surgery (tumor debulking/(+/-)ureterolysis/hysterectomy). MATERIALS/METHODS: The study cohort included OCa patients managed at our institution from 2004-2019 that developed OCa-associated HN. Initial HN management was recorded as none, retrograde ureteral stent (RUS) or percutaneous nephrostomy tube (PCN). Primary outcomes included (1) HN management failure, (2) HN management complications, and (3) HN resolution. Patient, cancer, and treatment predictors of outcomes were assessed using logistic regression and fine-Gray competing risk models. RESULTS: Of 2580 OCa patients, 190 (7.4%) developed HN. HN was treated in 121; 90 (74.4%) with RUS, 31 (25.6%) with PCN. Complication rates were similar between PCN and RUS (83% vs 85.1%; P = .79; all Clavian Grade I/II). Initial HN treatment failure occurred in 28 patients, predicted by renal atrophy (hazard ratios (HR) 3.27, P <.01). HN resolution occurred in only 52 (27%) patients and was predicted by lower International Federation of Gynecology and Obstetrics (FIGO) stage (FIGO III/IV HR 0.42, P <.01) and surgical tumor debulking/ureterolysis (HR 2.83, P = .02). CONCLUSION: Resolution of HN associated with malignant obstruction from OCa is rare and is most closely associated with tumor debulking and International Federation of Gynecology and Obstetrics (FIGO) stage. Initial endoscopic treatment modality was not significantly associated with complications or resolution, though RUS failures were slightly more common. Ureteral reconstruction at time of debulking/ureterolysis is potentially underutilized.


Subject(s)
Hydronephrosis , Ovarian Neoplasms , Ureter , Ureteral Obstruction , Female , Humans , Hydronephrosis/surgery , Ovarian Neoplasms/complications , Ovarian Neoplasms/surgery , Retrospective Studies , Stents/adverse effects , Treatment Failure , Ureter/surgery , Ureteral Obstruction/surgery , Ureteral Obstruction/complications
2.
Elife ; 122024 Feb 26.
Article in English | MEDLINE | ID: mdl-38407149

ABSTRACT

Rapid conversion of force into a biological signal enables living cells to respond to mechanical forces in their environment. The force is believed to initially affect the plasma membrane and then alter the behavior of membrane proteins. Phospholipase D2 (PLD2) is a mechanosensitive enzyme that is regulated by a structured membrane-lipid site comprised of cholesterol and saturated ganglioside (GM1). Here we show stretch activation of TWIK-related K+ channel (TREK-1) is mechanically evoked by PLD2 and spatial patterning involving ordered GM1 and 4,5-bisphosphate (PIP2) clusters in mammalian cells. First, mechanical force deforms the ordered lipids, which disrupts the interaction of PLD2 with the GM1 lipids and allows a complex of TREK-1 and PLD2 to associate with PIP2 clusters. The association with PIP2 activates the enzyme, which produces the second messenger phosphatidic acid (PA) that gates the channel. Co-expression of catalytically inactive PLD2 inhibits TREK-1 stretch currents in a biological membrane. Cellular uptake of cholesterol inhibits TREK-1 currents in culture and depletion of cholesterol from astrocytes releases TREK-1 from GM1 lipids in mouse brain. Depletion of the PLD2 ortholog in flies results in hypersensitivity to mechanical force. We conclude PLD2 mechanosensitivity combines with TREK-1 ion permeability to elicit a mechanically evoked response.


"Ouch!": you have just stabbed your little toe on the sharp corner of a coffee table. That painful sensation stems from nerve cells converting information about external forces into electric signals the brain can interpret. Increasingly, new evidence is suggesting that this process may be starting at fat-based structures within the membrane of these cells. The cell membrane is formed of two interconnected, flexible sheets of lipids in which embedded structures or molecules are free to move. This organisation allows the membrane to physically respond to external forces and, in turn, to set in motion chains of molecular events that help fine-tune how cells relay such information to the brain. For instance, an enzyme known as PLD2 is bound to lipid rafts ­ precisely arranged, rigid fatty 'clumps' in the membrane that are partly formed of cholesterol. PLD2 has also been shown to physically interact with and then activate the ion channel TREK-1, a membrane-based protein that helps to prevent nerve cells from relaying pain signals. However, the exact mechanism underpinning these interactions is difficult to study due to the nature and size of the molecules involved. To address this question, Petersen et al. combined a technology called super-resolution imaging with a new approach that allowed them to observe how membrane lipids respond to pressure and fluid shear. The experiments showed that mechanical forces disrupt the careful arrangement of lipid rafts, causing PLD2 and TREK-1 to be released. They can then move through the surrounding membrane where they reach a switch that turns on TREK-1. Further work revealed that the levels of cholesterol available to mouse cells directly influenced how the clumps could form and bind to PLD2, and in turn, dialled up and down the protective signal mediated by TREK-1. Overall, the study by Petersen et al. shows that the membrane of nerve cells can contain cholesterol-based 'fat sensors' that help to detect external forces and participate in pain regulation. By dissecting these processes, it may be possible to better understand and treat conditions such as diabetes and lupus, which are associated with both pain sensitivity and elevated levels of cholesterol in tissues.


Subject(s)
G(M1) Ganglioside , Signal Transduction , Animals , Mice , Second Messenger Systems , Cell Membrane , Cholesterol , Mammals
3.
Foods ; 12(20)2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37893732

ABSTRACT

Laboratory testing methods to confirm the identity of meat products and eliminate food fraud regularly rely on PCR amplification of extracted DNA, with most published assays detecting mitochondrial sequences, providing sensitive presence/absence results. By targeting single-copy nuclear targets instead, relative quantification measurements are achievable, providing additional information on the proportions of meat species detected. In this Methods paper, new assays for horse, donkey, duck, kangaroo, camel, water buffalo and crocodile have been developed to expand the range of species that can be quantified, and a previously published reference assay targeting the myostatin gene has been modified to include marsupials and reptiles. The accuracy of this ratio measurement approach was demonstrated using dPCR with mixtures of meat DNA down to 0.1%. However, the limit of detection (LOD) of this approach is not just determined by the assay targets, but by the samples themselves, with food or feed ingredients and processing impacting the DNA yield and integrity. In routine testing settings, the myostatin assay can provide multiple quality control roles, including monitoring the yield and purity of extracted DNA, identifying the presence of additional meats not detected by the suite of species-specific assays and potentially estimating a sample-specific LOD based on measured copy numbers of the myostatin target. In addition to the myostatin positive control assay, a synthetic DNA reference material (RM) has been designed, containing PCR targets for beef, pork, sheep, chicken, goat, kangaroo, horse, water buffalo and myostatin, to be used as a positive template control. The availability of standardised measurement methods and associated RMs significantly improves the reliability, comparability and transparency of laboratory testing, leading to greater confidence in results.

4.
FASEB J ; 35(3): e21412, 2021 03.
Article in English | MEDLINE | ID: mdl-33675257

ABSTRACT

While the administration of anti-CD154 mAbs in mice validated the CD40-CD154 pathway as a target against inflammatory disorders, this approach caused thromboembolism in humans (unrelated to CD40 inhibition) and is expected to predispose to opportunistic infections. There is a need for alternative approaches to inhibit CD40 that avoid these complications. CD40 signals through TRAF2,3 and TRAF6-binding sites. Given that CD40-TRAF6 is the pathway that stimulates responses key for cell-mediated immunity against opportunistic pathogens, we examined the effects of pharmacologic inhibition of CD40-TRAF2,3 signaling. We used a model of ischemia/reperfusion (I/R)-induced retinopathy, a CD40-driven inflammatory disorder. Intravitreal administration of a cell-penetrating CD40-TRAF2,3 blocking peptide impaired ICAM-1 upregulation in retinal endothelial cells and CXCL1 upregulation in endothelial and Müller cells. The peptide reduced leukocyte infiltration, upregulation of NOS2/COX-2/TNF-α/IL-1ß, and ameliorated neuronal loss, effects that mimic those observed after I/R in Cd40-/- mice. While a cell-penetrating CD40-TRAF6 blocking peptide also diminished I/R-induced inflammation, this peptide (but not the CD40-TRAF2,3 blocking peptide) impaired control of the opportunistic pathogen Toxoplasma gondii in the retina. Thus, inhibition of the CD40-TRAF2,3 pathway is a novel and potent approach to reduce CD40-induced inflammation, while likely diminishing the risk of opportunistic infections that would otherwise accompany CD40 inhibition.


Subject(s)
CD40 Antigens/drug effects , Inflammation/drug therapy , Neurons/drug effects , Peptides/pharmacology , TNF Receptor-Associated Factor 2/metabolism , Animals , CD40 Antigens/genetics , CD40 Antigens/metabolism , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Female , Humans , Inflammation/metabolism , Ischemia/drug therapy , Ischemia/metabolism , Male , Mice , Neurons/cytology , Reperfusion/methods , Signal Transduction/drug effects , Signal Transduction/physiology , TNF Receptor-Associated Factor 2/drug effects
5.
Ultrason Sonochem ; 73: 105502, 2021 May.
Article in English | MEDLINE | ID: mdl-33652291

ABSTRACT

Recent interest in biomass-based fuel blendstocks and chemical compounds has stimulated research efforts on conversion and upgrading pathways, which are considered as critical commercialization drivers. Existing pre-/post-conversion pathways are energy intense (e.g., pyrolysis and hydrogenation) and economically unsustainable, thus, more efficient process solutions can result in supporting the renewable fuels and green chemicals industry. This study proposes a process, including biomass conversion and bio-oil upgrading, using mixed fast and slow pyrolysis conversion pathway, as well as sono-catalytic transfer hydrogenation (SCTH) treatment process. The proposed SCTH treatment employs ammonium formate as a hydrogen transfer additive and palladium supported on carbon as the catalyst. Utilizing SCTH, bio-oil molecular bonds were broken and restructured via the phenomena of cavitation, rarefaction, and hydrogenation, with the resulting product composition, investigated using ultimate analysis and spectroscopy. Additionally, an in-line characterization approach is proposed, using near-infrared spectroscopy, calibrated by multivariate analysis and modeling. The results indicate the potentiality of ultrasonic cavitation, catalytic transfer hydrogenation, and SCTH for incorporating hydrogen into the organic phase of bio-oil. It is concluded that the integration of pyrolysis with SCTH can improve bio-oil for enabling the production of fuel blendstocks and chemical compounds from lignocellulosic biomass.


Subject(s)
Hydrogen/chemistry , Oils/chemistry , Pyrolysis , Ultrasonic Waves , Carbon/chemistry , Catalysis , Formates/chemistry , Palladium/chemistry , Spectroscopy, Near-Infrared
6.
J Biol Chem ; 296: 100458, 2021.
Article in English | MEDLINE | ID: mdl-33639159

ABSTRACT

Voltage-gated sodium channels (Navs) are tightly regulated by multiple conserved auxiliary proteins, including the four fibroblast growth factor homologous factors (FGFs), which bind the Nav EF-hand like domain (EFL), and calmodulin (CaM), a multifunctional messenger protein that binds the NaV IQ motif. The EFL domain and IQ motif are contiguous regions of NaV cytosolic C-terminal domains (CTD), placing CaM and FGF in close proximity. However, whether the FGFs and CaM act independently, directly associate, or operate through allosteric interactions to regulate channel function is unknown. Titrations monitored by steady-state fluorescence spectroscopy, structural studies with solution NMR, and computational modeling demonstrated for the first time that both domains of (Ca2+)4-CaM (but not apo CaM) directly bind two sites in the N-terminal domain (NTD) of A-type FGF splice variants (FGF11A, FGF12A, FGF13A, and FGF14A) with high affinity. The weaker of the (Ca2+)4-CaM-binding sites was known via electrophysiology to have a role in long-term inactivation of the channel but not known to bind CaM. FGF12A binding to a complex of CaM associated with a fragment of the NaV1.2 CTD increased the Ca2+-binding affinity of both CaM domains, consistent with (Ca2+)4-CaM interacting preferentially with its higher-affinity site in the FGF12A NTD. Thus, A-type FGFs can compete with NaV IQ motifs for (Ca2+)4-CaM. During spikes in the cytosolic Ca2+ concentration that accompany an action potential, CaM may translocate from the NaV IQ motif to the FGF NTD, or the A-type FGF NTD may recruit a second molecule of CaM to the channel.


Subject(s)
Calmodulin/metabolism , Fibroblast Growth Factors/metabolism , Amino Acid Sequence/genetics , Binding Sites/genetics , Calcium/metabolism , Calmodulin/physiology , EF Hand Motifs/genetics , Fibroblast Growth Factors/genetics , Humans , Models, Molecular , NAV1.2 Voltage-Gated Sodium Channel/metabolism , Nuclear Magnetic Resonance, Biomolecular/methods , Protein Binding , Protein Interaction Domains and Motifs/genetics , Voltage-Gated Sodium Channels/metabolism
7.
Sci Total Environ ; 722: 137894, 2020 Jun 20.
Article in English | MEDLINE | ID: mdl-32208262

ABSTRACT

Accurate prediction of Escherichia coli contamination in surface waters is challenging due to considerable uncertainty in the physical, chemical and biological variables that control E. coli occurrence and sources in surface waters. This study proposes a novel approach by integrating hydro-climatic variables as well as animal density and grazing pattern in the feature selection modeling phase to increase E. coli prediction accuracy for two cascading dams at the US Meat Animal Research Center (USMARC), Nebraska. Predictive models were developed using regression techniques and an artificial neural network (ANN). Two adaptive neuro-fuzzy inference system (ANFIS) structures including subtractive clustering and fuzzy c-means (FCM) clustering were also used to develop models for predicting E. coli. The performances of the predictive models were evaluated and compared using root mean squared log error (RMSLE). Cross-validation and model performance results indicated that although the majority of models predicted E. coli accurately, ANFIS models resulted in fewer errors compared to the other models. The ANFIS models have the potential to be used to predict E. coli concentration for intervention plans and monitoring programs for cascading dams, and to implement effective best management practices for grazing and irrigation during the growing season.


Subject(s)
Escherichia coli , Fuzzy Logic , Machine Learning , Neural Networks, Computer
8.
Sci Total Environ ; 705: 135607, 2020 Feb 25.
Article in English | MEDLINE | ID: mdl-31862534

ABSTRACT

Recent pathogenic Escherichia coli contamination of fresh vegetables that originated from irrigation water has increased awareness and importance of identifying sources of E. coli entering agroecosystems. However, inadequate methods for accurately predicting E. coli occurrence and sources in waterways continue to limit the identification of appropriate and effective prevention and treatment practices. Therefore, the primary objectives of this study were to: (1) Determine the concentration of E. coli during storm events in a hydrologic controlled stream situated in a livestock research operation that is located in the Central Flyway for avian migration in the United States. Great Plains; and (2) Identify trends between E. coli concentrations, grazing rotations, and avian migration patterns. The study sampled five rainfall events (three summer and two fall) to measure E. coli concentrations throughout storm events. A combination of cattle density and waterfowl migration patterns were found to significantly impact E. coli concentrations in the stream. Cattle density had a significant impact during the summer season (p < .0001), while waterfowl density had a significant impact on E. coli concentrations during the fall (p = .0422). The downstream reservoir had exceedance probabilities above the Environmental Protection Agency freshwater criteria > 85% of the growing season following rainfall events. Based on these findings, implementation of best management practices for reducing E. coli concentrations during the growing season and testing of irrigation water prior to application are recommended.


Subject(s)
Escherichia coli , Animals , Cattle , Fresh Water , Seasons , Water Microbiology
9.
IEEE Trans Biomed Circuits Syst ; 13(6): 1186-1200, 2019 12.
Article in English | MEDLINE | ID: mdl-31634842

ABSTRACT

A low-power, single-chip electronic skin interface is presented. The system on chip (SoC) implementation significantly reduces the physical footprint and power requirements compared to commercial interfaces, which enables the creation nimble prosthetic limbs. Its small size and reduced battery requirements are ideal for advanced prosthetics that utilize electronic skin to provide their user tactile feedback. The architecture consists of multiple charge-sensitive analog front ends (AFEs) interfaced to a central, 16-bit microcontroller core which is capable of processing the sensory information in real time. Event-driven operation allows the chip to monitor all input channels while consuming minimal energy. A test chip has been fabricated in a 0.13  µm CMOS technology and its functionality demonstrated by interfacing the chip to a prototype electronic skin based on polyvinylidene fluoride (PVDF) piezoelectric sensors. Tactile signals from the sensors are measured and processed on-chip to calculate the corresponding charge. This is accomplished by programming the microcontroller with a custom software algorithm, granting the system the flexibility to interface to different types of sensors. The single-chip electronic skin system consumes 7.0 µW per channel and 93.5 µW in the example application when stimulated at 1 Hz, making it suitable for use with battery-powered prosthetics.


Subject(s)
Equipment Design/methods , Wearable Electronic Devices , Electric Power Supplies , Humans , Prostheses and Implants , Signal Processing, Computer-Assisted , Wireless Technology
10.
J Environ Manage ; 250: 109424, 2019 Nov 15.
Article in English | MEDLINE | ID: mdl-31472378

ABSTRACT

Atrazine, one of the most widely used herbicides in the world, threatens human health along with terrestrial and aquatic biota. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin's Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. The Midwest region of the United States, which includes Nebraska, is one of the leading regions for high nitrate-N concentrations and agrochemicals, including atrazine, in surface waters. Therefore, the objective of this study was to provide a case study for completing an environmental risk analysis for the potential exposure of atrazine and nitrate-N to ecosystems and humans through interaction with surface waters using two approaches: (1) Identify watersheds across Nebraska that were at risk for exceeding atrazine and nitrate-N maximum contaminant limits (MCLs) in surface water; and (2) Determine the specific times of year where risks were greatest. Factors were then analyzed using Geographic Information System (GIS) software to identify areas of high risk. Impairments for both nitrate-N and atrazine in the surface water were found predominately during the early growing season in the southeastern region of Nebraska, in watershed areas with the highest amount of corn production and annual precipitation. Further, the methodology developed in this study has the potential for application in regions with higher dependency on surface water to determine multiple agrochemical load influxes from upstream regions and evaluate other surface water contaminants during the same time periods.


Subject(s)
Atrazine , Herbicides , Water Pollutants, Chemical , Ecosystem , Environmental Monitoring , Humans , Nebraska
11.
J Cogn Neurosci ; 31(12): 1946-1957, 2019 12.
Article in English | MEDLINE | ID: mdl-31418336

ABSTRACT

During conversation, speakers monitor their own and others' output so they can alter their production adaptively, including halting it if needed. We investigated the neural mechanisms of monitoring and halting in spoken word production by employing a modified stop signal task during fMRI. Healthy participants named target pictures and withheld their naming response when presented with infrequent auditory words as stop signals. We also investigated whether the speech comprehension system monitors inner (i.e., prearticulatory) speech via the output of phonological word form encoding as proposed by the perceptual loop theory [Levelt, W. J. M. Speaking: From intention to articulation. Cambridge, MA: MIT Press, 1989] by presenting stop signals phonologically similar to the target picture name (e.g., cabbage-CAMEL). The contrast of successful halting versus naming revealed extensive BOLD signal responses in bilateral inferior frontal gyrus, preSMA, and superior temporal gyrus. Successful versus unsuccessful halting of speech was associated with increased BOLD signal bilaterally in the posterior middle temporal, frontal, and parietal lobes and decreases bilaterally in the posterior and left anterior superior temporal gyrus and right inferior frontal gyrus. These results show, for the first time, the neural mechanisms engaged during both monitoring and interrupting speech production. However, we failed to observe any differential effects of phonological similarity in either the behavioral or neural data, indicating monitoring of inner versus external speech might involve different mechanisms.


Subject(s)
Cerebral Cortex/physiology , Inhibition, Psychological , Speech/physiology , Verbal Behavior/physiology , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Models, Neurological , Models, Psychological , Volition , Young Adult
12.
Cell Microbiol ; 21(10): e13084, 2019 10.
Article in English | MEDLINE | ID: mdl-31290228

ABSTRACT

Toxoplasma gondii causes retinitis and encephalitis. Avoiding targeting by autophagosomes is key for its survival because T. gondii cannot withstand lysosomal degradation. During invasion of host cells, T. gondii triggers epidermal growth factor receptor (EGFR) signalling enabling the parasite to avoid initial autophagic targeting. However, autophagy is a constitutive process indicating that the parasite may also use a strategy operative beyond invasion to maintain blockade of autophagic targeting. Finding that such a strategy exists would be important because it could lead to inhibition of host cell signalling as a novel approach to kill the parasite in previously infected cells and treat toxoplasmosis. We report that T. gondii induced prolonged EGFR autophosphorylation. This effect was mediated by PKCα/PKCß âž” Src because T. gondii caused prolonged activation of these molecules and their knockdown or incubation with inhibitors of PKCα/PKCß or Src after host cell invasion impaired sustained EGFR autophosphorylation. Addition of EGFR tyrosine kinase inhibitor (TKI) to previously infected cells led to parasite entrapment by LC3 and LAMP-1 and pathogen killing dependent on the autophagy proteins ULK1 and Beclin 1 as well as lysosomal enzymes. Administration of gefitinib (EGFR TKI) to mice with ocular and cerebral toxoplasmosis resulted in disease control that was dependent on Beclin 1. Thus, T. gondii promotes its survival through sustained EGFR signalling driven by PKCα/ß âž” Src, and inhibition of EGFR controls pre-established toxoplasmosis.


Subject(s)
Autophagosomes/metabolism , Autophagosomes/parasitology , Autophagy , ErbB Receptors/metabolism , Toxoplasmosis, Animal/drug therapy , Toxoplasmosis, Animal/metabolism , Animals , Autophagosomes/drug effects , Autophagosomes/enzymology , Autophagy/drug effects , Autophagy/genetics , Beclin-1/metabolism , Cell Line , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Endothelial Cells/ultrastructure , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Female , Gefitinib/therapeutic use , Humans , Lysosomal-Associated Membrane Protein 1/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microscopy, Electron, Transmission , Phosphorylation , Protein Kinase C beta/antagonists & inhibitors , Protein Kinase C beta/genetics , Protein Kinase C beta/metabolism , Protein Kinase C-alpha/antagonists & inhibitors , Protein Kinase C-alpha/metabolism , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins pp60(c-src)/antagonists & inhibitors , Proto-Oncogene Proteins pp60(c-src)/genetics , Proto-Oncogene Proteins pp60(c-src)/metabolism , Toxoplasma/drug effects , Toxoplasma/pathogenicity , Toxoplasmosis, Animal/enzymology , Toxoplasmosis, Animal/genetics
13.
Soc Cogn Affect Neurosci ; 14(3): 271-279, 2019 03 05.
Article in English | MEDLINE | ID: mdl-30715549

ABSTRACT

Every language has words deemed to be socially inappropriate or 'taboo' to utter. Taboo word production appears prominently in language disorders following brain injury. Yet, we know little about the cognitive and neural mechanisms involved in processing taboo compared to neutral language. In the present study, we introduced taboo distractor words in the picture word interference paradigm during functional magnetic resonance imaging to investigate how these words influence spoken word production. Taboo distractor words significantly slowed picture-naming latencies compared to neutral words. This interference effect was associated with increased blood oxygen level dependent signal across a distributed thalamo-cortical network including bilateral anterior cingulate cortex and left inferior frontal gyrus, left posterior middle temporal gyrus and right thalamus. We interpret our findings as being consistent with an account integrating both domain-general attention-capture/distractor blocking and language-specific mechanisms in processing taboo words during spoken word production.


Subject(s)
Language , Taboo , Temporal Lobe/physiology , Adult , Attention/physiology , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Oxygen/blood , Young Adult
14.
Q J Exp Psychol (Hove) ; 70(1): 75-91, 2017 Jan.
Article in English | MEDLINE | ID: mdl-26629985

ABSTRACT

Speakers respond more slowly when naming pictures presented with taboo (i.e., offensive/embarrassing) than with neutral distractor words in the picture-word interference paradigm. Over four experiments, we attempted to localize the processing stage at which this effect occurs during word production and determine whether it reflects the socially offensive/embarrassing nature of the stimuli. Experiment 1 demonstrated taboo interference at early stimulus onset asynchronies of -150 ms and 0 ms although not at 150 ms. In Experiment 2, taboo distractors sharing initial phonemes with target picture names eliminated the interference effect. Using additive factors logic, Experiment 3 demonstrated that taboo interference and phonological facilitation effects do not interact, indicating that the two effects originate at different processing levels within the speech production system. In Experiment 4, interference was observed for masked taboo distractors, including those sharing initial phonemes with the target picture names, indicating that the effect cannot be attributed to a processing level involving responses in an output buffer. In two of the four experiments, the magnitude of the interference effect correlated significantly with arousal ratings of the taboo words. However, no significant correlations were found for either offensiveness or valence ratings. These findings are consistent with a locus for the taboo interference effect prior to the processing stage responsible for word form encoding. We propose a pre-lexical account in which taboo distractors capture attention at the expense of target picture processing due to their high arousal levels.

15.
J Exp Psychol Gen ; 142(1): 131-142, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22642711

ABSTRACT

Studies of semantic context effects in spoken word production have typically distinguished between categorical (or taxonomic) and associative relations. However, associates tend to confound semantic features or morphological representations, such as whole-part relations and compounds (e.g., BOAT-anchor, BEE-hive). Using a picture-word interference paradigm and functional magnetic resonance imaging (fMRI), we manipulated categorical (COW-rat) and thematic (COW-pasture) TARGET-distractor relations in a balanced design, finding interference and facilitation effects on naming latencies, respectively, as well as differential patterns of brain activation compared with an unrelated distractor condition. While both types of distractor relation activated the middle portion of the left middle temporal gyrus (MTG) consistent with retrieval of conceptual or lexical representations, categorical relations involved additional activation of posterior left MTG, consistent with retrieval of a lexical cohort. Thematic relations involved additional activation of the left angular gyrus. These results converge with recent lesion evidence implicating the left inferior parietal lobe in processing thematic relations and may indicate a potential role for this region during spoken word production.


Subject(s)
Attention/physiology , Brain/physiology , Concept Formation/physiology , Knowledge , Speech/physiology , Adolescent , Adult , Brain Mapping , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Reaction Time/physiology , Semantics
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