Molecular characterization of Sarcoptes scabiei causing severe mange in two Andean foxes (Lycalopex culpaeus) from Peru.

Cases of sarcoptic mange in the wildlife population have been increasing around the world in recent years. In this study, we report the first case of severe sarcoptic mange in two Andean foxes (Lycalopex culpaeus) and molecularly analyze the collected mites. The National Forestry and Wildlife Service of Lima, Peru, found an adult male Andean fox in the province of Callao in August 2022. The veterinarians decided to euthanize the fox due to the severity of the mange. In August 2023, an adult male Andean fox was found dead in the province of Huaral by veterinarians. Both foxes were sent to the veterinary school in Lima for necropsy. Skin samples from different body zones were digested in buffer lysis, and mites were detected in the tissue samples. A morphological diagnosis identified the mites as Sarcoptes scabiei. The mites from both foxes had the same nuclear (ITS2) and mitochondrial (cox1) genetic marker sequences as the S. scabiei sequences from dogs, vicunas, Andean foxes, and water buffalos recorded in GenBank. Unlike ITS2, phylogenetic analysis of S. scabiei cox1 showed host-related nucleotide sequence polymorphisms. Future molecular studies of S. scabiei from different hosts and localities will be necessary to better understand the transmission of this disease in Andean foxes.

Personal exposure to radiofrequency electromagnetic fields in various occupations in Spain and France.

BACKGROUND: A preliminary job-exposure matrix (JEM) for radiofrequency electromagnetic fields (RF-EMF) was created based on self-reported occupational information from a multi-country population-based study of approximately 10,000 participants combined with available measurement data compiled in a source-exposure matrix (spot measurements). In order to address the limited personal occupational RF-EMF measurement data available in the literature, we performed a measurement campaign among workers in various occupations in Spain and France. METHODS: Personal full-shift measurements were conducted using RadMan 2XT™ (Narda) devices. A worker diary was used to capture information on occupational and background sources of RF exposure during the shift. Inclusion of occupations to be measured was initially based on exposure prevalence and level information in the preliminary JEM and expert judgment. RESULTS: Personal full-shift measurements were conducted among 333 workers representing 46 ISCO88 occupations. Exposure to electric (E) and magnetic (H) fields was infrequent with >99% of measurements below the detection limit of the device (≥1% of the 1998 ICNIRP standards). A total of 50.2% and 77.2% of workers were ever exposed to E and H fields respectively (having at least one recorded 1-second measurement above the detection limit). Workers in elementary occupations, technicians and associate professionals, plant and machine operators and assemblers had somewhat greater numbers of measurements above the detection limit, higher maximum values and longer exposure durations. A small proportion of measurements were ≥100% of the standards, though these exceedances were brief (generally a few seconds in duration). Female workers and workers reporting use of any RF-EMF emitting source were more likely to have a measured exposure to E and H fields. CONCLUSION: We conducted personal RF-EMF measurements among workers in various occupations in Spain and France. Overall, RF-EMF exposure ≥1 % ICNIRP was infrequent, despite some intermittent exposures ≥100% observed among workers in some occupations.

Identification of wild rodents as intermediate hosts for Hydatigera taeniaeformis in Peru.

Hydatigera taeniaeformis is a cestode that uses felines and rodents as definitive and intermediate hosts, respectively. Its larval stage, or metacestode, infects a wide variety of rodent species and develops in the liver parenchyma into a cyst. The aim of this study was to evaluate the occurrence of H. taeniaeformis metacestode in various species of wild rodents from Peru. For this, the livers of 356 rodents were macroscopically examined for any parasitic form compatible with metacestodes. Metacestodes were identified by measuring characteristic morphological parameters, and the diagnosis was confirmed by molecular analysis of a fragment of the cytochrome c oxidase subunit 1 gene (cox1). Five rodents: two small-eared pygmy rice rats (Oligoryzomys microtis), two white-naped squirrels (Simosciurus nebouxii), and one pygmy rice rat (Oligoryzomys sp.) were infected with H. taeniaeformis metacestodes. The cox1 sequences from our metacestodes showed up to 100% identity with previous H. taeniaeformis sequences from the GenBank. These results demonstrated the occurrence of H. taeniaeformis in new intermediate hosts, as well as the first molecular contribution for H. taeniaeformis from Peru.

"Can we study episodic-like memory in preschoolers from an animal foraging model": Correction.

Reports an error in "Can we study episodic-like memory in preschoolers from an animal foraging model" by Javier Vila, Eneida Strempler-Rubio and Angélica Alvarado (Journal of Experimental Psychology: Animal Learning and Cognition, 2021[Jul], Vol 47[3], 357-363). In the original article, a repeated measure analysis of variance was calculated with incorrect numerator and denominator degrees of freedom, which resulted in incorrect F, MSE, and R² values being reported in the Results section. When calculated correctly, the significant differences found in the new analysis of variance were the same as before. The results and conclusions are unchanged. The online version of this article has been corrected. (The following abstract of the original article appeared in record 2021-92066-011). Episodic-like memory (ELM) involves remembering the what, where, and when (WWW) of an event as a whole, and it can be studied behaviorally. In research regarding this type of memory with children, one experiment proposes a new task adapted from animal foraging studies. A task derived from a foraging model was presented its considers the characteristics required for ELM study in children and employs a single trial presented from an egocentric perspective to avoid memory consolidation. One study compared four-year-old children's choices after being trained with one or three trials using a hide-and-seek task. The consequence size and retention interval between training and test were manipulated. Results showed that children chose the optimal outcome after an immediate or delayed test. The children's choices were conditional on the size of the consequences and the time at retrieval according to the Temporal Weighting Rule (Devenport & Devenport, 1994). The results were similar to those of animal studies and were consistent with a foraging memory model. In discussion, the advantages and limitations of the proposed task for the study of ELM in children are described and explained. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Can we study episodic-like memory in preschoolers from an animal foraging model?

Episodic-like memory (ELM) involves remembering the what, where, and when (WWW) of an event as a whole, and it can be studied behaviorally. In research regarding this type of memory with children, one experiment proposes a new task adapted from animal foraging studies. A task derived from a foraging model was presented its considers the characteristics required for ELM study in children and employs a single trial presented from an egocentric perspective to avoid memory consolidation. One study compared four-year-old children's choices after being trained with one or three trials using a hide-and-seek task. The consequence size and retention interval between training and test were manipulated. Results showed that children chose the optimal outcome after an immediate or delayed test. The children's choices were conditional on the size of the consequences and the time at retrieval according to the Temporal Weighting Rule (Devenport & Devenport, 1994). The results were similar to those of animal studies and were consistent with a foraging memory model. In discussion, the advantages and limitations of the proposed task for the study of ELM in children are described and explained. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Mandibular movement analisys by means of a kinematic model applied to the design of oral appliances for the treatment of obstructive sleep apnea.

BACKGROUND: Mandibular advancement devices (MADs) are one of the treatment options used for the obstructive sleep apnea syndrome (OSAS). At present, MADs are designed with standard titration systems, without considering each patient's anatomical characteristics of the temporomandibular joint and mandible shape. The main objective of this study is to evaluate if a variability in mandibular morphology will influence the displacement of the jaw with a MAD. Such knowledge will be of help to find optimal mandibular positions with MAD even when opening the mouth. METHODS: By using a mandibular movement model, the movement patterns of different points on the chin have been analyzed. The influence of different skeletal mandibular shapes on these movements have also been studied. The results show differences in the movement patterns of the lower front teeth depending on its distance to the center of the condyle, with a more horizontal direction in those in which there is a greater distance. RESULTS: Variations in mandibular morphology imply differences in movement patterns of the analyzed points of the mandible. Consequently, MADs should be designed according to each patient's anatomy to avoid mandibular retrusion in those areas that may narrow the upper airways. CONCLUSIONS: This study may help to understand why not all patients move their lower jaws forwards equally with the same degree of mandibular protrusion measured in relation to the teeth. These results might also partially explain why airway obstruction is more severe in certain untreated sleep apnea subjects than in others when opening their mouth during sleep.

Occupational Exposure to Pesticides and Chronic Lymphocytic Leukaemia in the MCC-Spain Study.

We aimed to study the association between occupational exposure to pesticides and chronic lymphocytic leukemia (CLL) in Spain. Occupational exposure to pesticides (four insecticides, four herbicides and two fungicides) was evaluated using a job-exposure matrix for the Spanish population (MatEmESp) among 302 CLL cases and 1567 population controls in five regions of Spain, 2010-2013. Cumulative exposure scores (CES) were obtained by summing across the exposed jobs the product of prevalence, intensity and duration of exposure to each active substance. Principal components analysis (PCA) and logistic regression models adjusted for age, sex, region, education and occupational exposure to solvents were used. Around 20% of controls and 29% of cases were exposed to one or more pesticides. Compared to non-exposed, subjects in the highest tertile (3rd tertile) of CES of insecticides, herbicides, fungicides were more likely to have CLL [OR (95% CI), P-trend; 2.10 (1.38; 3.19), 0.002; 1.77 (1.12; 2.80), 0.12; and 1.67 (1.06; 2.64), 0.10, respectively). Following PCA, the first component (PC1, explaining 70% of the variation) equally led by seven active substances (the insecticide pyrethrin, all herbicides, all fungicides) was associated with a 26% higher odds of having CLL for 1-standard deviation increase in PC1 (95% CI: 1.14 to 1.40). These results confirm previous associations between CLL and exposure to pesticides and provide additional evidence by application groups and active substance. However, more research is needed to disentangle independent effects of individual active substances.

Development of a Job-Exposure Matrix for Assessment of Occupational Exposure to High-Frequency Electromagnetic Fields (3 kHz-300 GHz).

OBJECTIVES: The aim of this work was to build a job-exposure matrix (JEM) using an international coding system and covering the non-thermal intermediate frequency (IF) (3-100 kHz, named IFELF), thermal IF (100 kHz-10 MHz, named IFRF), and radiofrequency (RF) (>10 MHz) bands. METHODS: Detailed occupational data were collected in a large population-based case-control study, INTEROCC, with occupations coded into the International Standard Classification of Occupations system 1988 (ISCO88). The subjects' occupational source-based ancillary information was combined with an existing source-exposure matrix and the reference levels of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) for occupational exposure to calculate estimates of level (L) of exposure to electric (E) and magnetic (H) fields by ISCO88 code and frequency band as ICNIRP ratios (IFELF) or squared ratios (IFRF and RF). Estimates of exposure probability (P) were obtained by dividing the number of exposed subjects by the total number of subjects available per job title. RESULTS: With 36 011 job histories collected, 468 ISCO88 (four-digit) codes were included in the JEM, of which 62.4% are exposed to RF, IFRF, and/or IFELF. As a reference, P values for RF E-fields ranged from 0.3 to 65.0% with a median of 5.1%. L values for RF E-fields (ICNIRP squared ratio) ranged from 6.94 × 10-11 to 33.97 with a median of 0.61. CONCLUSIONS: The methodology used allowed the development of a JEM for high-frequency electromagnetic fields containing exposure estimates for the largest number of occupations to date. Although the validity of this JEM is limited by the small number of available observations for some codes, this JEM may be useful for epidemiological studies and occupational health management programs assessing high-frequency electromagnetic field exposure in occupational settings.

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring: findings from the Childhood Leukaemia International Consortium (CLIC).

OBJECTIVES: Previously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium. METHODS: We pooled 11 case-control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses. RESULTS: ORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses. CONCLUSIONS: In this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia.

Correction: Development of a source-exposure matrix for occupational exposure assessment of electromagnetic fields in the INTEROCC study.

Corrigendum: This work was also funded by the European Commission grant 603794 (GERoNiMO project).

Clinical Practice Guideline recommendations on examination of the upper airway for adults with suspected obstructive sleep apnoea-hypopnoea syndrome. / Recomendaciones de la Guía de Práctica Clínica de la exploración de la vía aérea superior para pacientes adultos con sospecha de síndrome de apnea-hipoapnea obstructiva del sueño (versión reducida).

In November 2014 the Spanish Society of Otolaryngology, the Spanish Sleep Society and the Spanish Society of Maxillofacial Surgery proposed and endorsed the development of a Clinical Practice Guideline on the physical examination of the upper airway in patients with obstructive sleep apnoea. The Guideline strictly followed the recommendations of the manual for the preparation of clinical practice guidelines of the National Health System 2007 and 2009 and the manual of the Scottish Intercollegiate Guidelines Network (SIGN) 2015. The final document could be highly useful for the purposes that were originally proposed: to act as a reference to unify the regions that should be explored in patients with obstructive sleep apnoea-hypopnoea syndrome, the type of examination and how to grade it, and specific to all the care areas to which these patients have access. The conclusions and recommendations are based on a thorough and up-to-date review of the literature with a high level of evidence, as well as the experience and knowledge demonstrated by all the members of the drafting group. This group was formed bearing in mind at all times the transversality of the project, and, therefore, specialists from all the involved areas participated (maxillofacial surgery, family medicine, pneumology, clinical neurophysiology, odontology and otolaryngology). The external reviewers of the final text were selected along the same lines.

Occupational exposure to high-frequency electromagnetic fields and brain tumor risk in the INTEROCC study: An individualized assessment approach.

INTRODUCTION: In 2011, the International Agency for Research on Cancer classified radiofrequency (RF) electromagnetic fields (EMF) as possibly carcinogenic to humans (group 2B), although the epidemiological evidence for the association between occupational exposure to RF-EMF and cancer was judged to be inadequate, due in part to limitations in exposure assessment. This study examines the relation between occupational RF and intermediate frequency (IF) EMF exposure and brain tumor (glioma and meningioma) risk in the INTEROCC multinational population-based case-control study (with nearly 4000 cases and over 5000 controls), using a novel exposure assessment approach. METHODS: Individual indices of cumulative exposure to RF and IF-EMF (overall and in specific exposure time windows) were assigned to study participants using a source-exposure matrix and detailed interview data on work with or nearby EMF sources. Conditional logistic regression was used to investigate associations with glioma and meningioma risk. RESULTS: Overall, around 10% of study participants were exposed to RF while only 1% were exposed to IF-EMF. There was no clear evidence for a positive association between RF or IF-EMF and the brain tumors studied, with most results showing either no association or odds ratios (ORs) below 1.0. The largest adjusted ORs were obtained for cumulative exposure to RF magnetic fields (as A/m-years) in the highest exposed category (≥90th percentile) for the most recent exposure time window (1-4 years before the diagnosis or reference date) for both glioma, OR = 1.62 (95% confidence interval (CI): 0.86, 3.01) and meningioma (OR = 1.52, 95% CI: 0.65, 3.55). CONCLUSION: Despite the improved exposure assessment approach used in this study, no clear associations were identified. However, the results obtained for recent exposure to RF electric and magnetic fields are suggestive of a potential role in brain tumor promotion/progression and should be further investigated.

Amplitude-dependent topological edge states in nonlinear phononic lattices.

This work investigates the effect of nonlinearities on topologically protected edge states in one- and two-dimensional phononic lattices. We first show that localized modes arise at the interface between two spring-mass chains that are inverted copies of each other. Explicit expressions derived for the frequencies of the localized modes guide the study of the effect of cubic nonlinearities on the resonant characteristics of the interface, which are shown to be described by a Duffing-like equation. Nonlinearities produce amplitude-dependent frequency shifts, which in the case of a softening nonlinearity cause the localized mode to migrate to the bulk spectrum. The case of a hexagonal lattice implementing a phononic analog of a crystal exhibiting the quantum spin Hall effect is also investigated in the presence of weakly nonlinear cubic springs. An asymptotic analysis provides estimates of the amplitude dependence of the localized modes, while numerical simulations illustrate how the lattice response transitions from bulk-to-edge mode-dominated by varying the excitation amplitude. In contrast with the interface mode of the first example studies, this occurs both for hardening and softening springs. The results of this study provide a theoretical framework for the investigation of nonlinear effects that induce and control topologically protected wave modes through nonlinear interactions and amplitude tuning.

Development of a source-exposure matrix for occupational exposure assessment of electromagnetic fields in the INTEROCC study.

To estimate occupational exposures to electromagnetic fields (EMF) for the INTEROCC study, a database of source-based measurements extracted from published and unpublished literature resources had been previously constructed. The aim of the current work was to summarize these measurements into a source-exposure matrix (SEM), accounting for their quality and relevance. A novel methodology for combining available measurements was developed, based on order statistics and log-normal distribution characteristics. Arithmetic and geometric means, and estimates of variability and maximum exposure were calculated by EMF source, frequency band and dosimetry type. The mean estimates were weighted by our confidence in the pooled measurements. The SEM contains confidence-weighted mean and maximum estimates for 312 EMF exposure sources (from 0 Hz to 300 GHz). Operator position geometric mean electric field levels for radiofrequency (RF) sources ranged between 0.8 V/m (plasma etcher) and 320 V/m (RF sealer), while magnetic fields ranged from 0.02 A/m (speed radar) to 0.6 A/m (microwave heating). For extremely low frequency sources, electric fields ranged between 0.2 V/m (electric forklift) and 11,700 V/m (high-voltage transmission line-hotsticks), whereas magnetic fields ranged between 0.14 µT (visual display terminals) and 17 µT (tungsten inert gas welding). The methodology developed allowed the construction of the first EMF-SEM and may be used to summarize similar exposure data for other physical or chemical agents.

Flexibilidad de la memoria tipo episódica en niños preescolares: tiempo y consecuencia / Flexibility of episodic-like memory in preschool children: Time and consequence

Resumen: La memoria tipo episódica (MTE) implica recordar de manera integrada el qué, el dónde y el cuándo de un evento y es atribuible a animales y humanos, permitiendo recordar y actualizar lo aprendido. Se realizó un experimento para estudiar la actualización y recuerdo integrado en la MTE de niños prescolares. Se compararon dos condiciones (A=B y A>B) que involucraron más de dos fases en las que varió la magnitud para una de las consecuencias. En una primera fase ambas condiciones presentaron la misma información (A+, B+ y C+), mientras que las fases subsecuentes se presentaron diferentes magnitudes de consecuencia (segunda fase: A++++ o A**** de acuerdo a la condición; tercera fase: B++++). Finalmente, la prueba ocurrió 24 h después del entrenamiento y los participantes eligieron entre el contenedor A o B. El qué fue la consecuencia; el dónde, los contenedores, y el cuándo, el orden de cada fase presentada. Los datos sugieren que tras el paso del tiempo los participantes recuerdan de manera integrada el qué, el dónde y el cuándo actualizando el aprendizaje de cada experiencia. Los participantes consideraron la magnitud de la consecuencia obtenida en cada fase, mostrando así la flexibilidad del recuerdo propuesta por la MTE. Los datos son coherentes con las predicciones de la Regla de Ponderación Temporal de Devenport.

Abstract: Episodic-like memory (ELM) involves that animals can remember What, Where and When about an event and it is attributable to animals and humans, this ability permits recall and update learning. One experiment was made for study the update and integrated recall of ELM in preschoolers. We compared two conditions (A = B and A > B) that involve more than two phases with modifying of one magnitude outcome. In the first phase, both conditions had the same information, while next phases had different outcome value in two containers (A or B). Finally, a test was presented after 24 hours: participants chose between A or B container. What, was the outcome subjective value; Where, was the containers and When was the order to each phase. Data suggest that after time pass, participants remember an integrated way about What, Where and When. Even when participants update learning for each experience participants chose according to time and outcome subjective value of each phase and the information retrieval is flexible as happen with ELM. Results are consistent with predictions of Devenport's Temporal Weighting Rule.

A Source-based Measurement Database for Occupational Exposure Assessment of Electromagnetic Fields in the INTEROCC Study: A Literature Review Approach.

INTRODUCTION: To date, occupational exposure assessment of electromagnetic fields (EMF) has relied on occupation-based measurements and exposure estimates. However, misclassification due to between-worker variability remains an unsolved challenge. A source-based approach, supported by detailed subject data on determinants of exposure, may allow for a more individualized exposure assessment. Detailed information on the use of occupational sources of exposure to EMF was collected as part of the INTERPHONE-INTEROCC study. To support a source-based exposure assessment effort within this study, this work aimed to construct a measurement database for the occupational sources of EMF exposure identified, assembling available measurements from the scientific literature. METHODS: First, a comprehensive literature search was performed for published and unpublished documents containing exposure measurements for the EMF sources identified, a priori as well as from answers of study subjects. Then, the measurements identified were assessed for quality and relevance to the study objectives. Finally, the measurements selected and complementary information were compiled into an Occupational Exposure Measurement Database (OEMD). RESULTS: Currently, the OEMD contains 1624 sets of measurements (>3000 entries) for 285 sources of EMF exposure, organized by frequency band (0 Hz to 300 GHz) and dosimetry type. Ninety-five documents were selected from the literature (almost 35% of them are unpublished technical reports), containing measurements which were considered informative and valid for our purpose. Measurement data and complementary information collected from these documents came from 16 different countries and cover the time period between 1974 and 2013. CONCLUSION: We have constructed a database with measurements and complementary information for the most common sources of exposure to EMF in the workplace, based on the responses to the INTERPHONE-INTEROCC study questionnaire. This database covers the entire EMF frequency range and represents the most comprehensive resource of information on occupational EMF exposure. It is available at www.crealradiation.com/index.php/en/databases.

[Usefulness of the basic exploration of the upper airways and neighbor structures in patients with adult obstructive sleep apnea-hypopnea syndrome]. / Utilidad de la exploración básica de la vía aérea superior y estructuras vecinas en los pacientes adultos con síndrome de apnea-hipopnea obstructiva del sueño.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a prevalent disease in the general population, associated with an increase in the cardiovascular morbimortality. A basic and/or standardized otolaryngologic exploration could help us to detect the structural abnormalities that alter the upper airway collapsibility and offer a high pre-test risk factor, improve the CPAP adherence or even the possibility of offering alternative treatments. This article offers a revision of the exploration in OSAHS patients. We describe a guideline to identify the main structural abnormalities related to OSAHS. We also include a short algorithm for the diagnosis of OSAHS, when is suspected by primary care physicians.

La generalización entre contextos como función del entrenamiento en una tarea instrumental con humanos / Generalization among Contexts as a Function of Training Humans in an Instrumental Task

León, Abad y Rosas, (2010b) demostraron que la atención al contexto se pierde conforme aumenta el entrenamiento. Así, a medida que aumenta el entrenamiento se observa una mayor generalización entre contextos distintos al de entrenamiento al perderse la atención. El objetivo del presente estudio fue poner a prueba ésta idea empleando una tarea instrumental en humanos con distintos valores del contexto (color). La tarea consistió en un juego de ordenador en el que se emitían distintas respuestas bajo un programa IV2s, en presencia de distintos estímulos discriminativos. En el Experimento 1 se entrenaron dos grupos con 3 y 8 ensayos, posteriormente se realizó un ensayo de prueba en el contexto de entrenamiento (amarillo) y en un contexto diferente (rojo). Los resultados demostraron una disminución de la ejecución con el cambio de contexto. En el Experimento 2 se entrenaron dos grupos de manera similar al Experimento 1, empleando un contexto naranja. Durante la prueba se presentaron degradaciones del color del contexto de entrenamiento con valores intermedios hacia el color amarillo y rojo. Los resultados sugieren que la atención al contexto de entrenamiento está modulada diferencialmente por la cantidad de entrenamiento en la tarea.

León, Abad and Rosas (2010b) shown that as the training increased attention to the context decreased. Thus, increasing the training might produce a greater generalization between different contexts. The main goal of the present experiments was to test this idea modifying different values of the context (i. e., colors) using an instrumental task with humans. The task was a videogame in which participants performed under an IV2s schedule in presence of different discriminative stimuli to obtain reinforces. In Experiment 1 two groups were trained with 3 or 8 trials, then a test trial was conducted in the training context (i. e., yellow) or in a different context (i. e., red). Results shown that changed the context produced a loss of performance. In Experiment 2 two groups were trained with similar parameters used in Experiment 1 but using an orange context. Test was conducted with different values of the orange (i. e., training context) toward yellow and red. The pattern of the data suggests that experience with the task modulates in different ways attention to contextual cues.