ABSTRACT
Ten free-living adult coatis (two males and eight females) were chemically restrained with "ZAD-50", a concentrated formulation prepared with the dehydrated content of a Zoletil/50® vial diluted with 0.25mL of 1% atropine, 0.265mL of Dormiun-V®, and 2.2mL of distilled water, being exactly 3.0mL. The formula was administered to each animal previously captured and physically contained with a net. The loss of righting reflex (RR) occurred at 2.3±0.8 minutes post-injection (MPI), with anesthesia beginning at 4.4±2.7 MPI. Myorelaxant and analgesia were considered excellent at all moments of the evaluation. Conscious reactions were observed at 78.7±22.2 MPI, the return of the RR occurred at 101 ± 18 MPI, and normal ambulation was acquired at 137.0±31.0 MPI. The mean values ââof physiological parameters measured every 10 minutes between 10 and 50 MPI were 152.2 heartbeats per minute for heart rate, 66.4 respiratory movements per minute for respiratory rate, 39.2oC for rectal temperature, 86.2% for SpO2 and 14.6 mmHg for systolic blood pressure. In the same times, the EEG registered sinus rhythm. No adverse reactions were observed, and the assessed vital parameters remained compatible with the state of chemical restraint.(AU)
Dez quatis adultos de vida livre (dois machos e oito fêmeas) foram contidos empregando-se a formulação denominada "ZAD-50". A fórmula foi preparada a partir do conteúdo desidratado de um frasco de Zoletil/50® diluído em 0,25mL de atropina a 1%, 0,265mL de Dormiun-V® e 2,2mL de água destilada, obtendo-se volume final de 3,0mL. A associação foi administrada, por via intramuscular, a cada animal capturado e contido fisicamente com puçá, em dose calculada por meio de extrapolação alométrica interespecífica. A perda da reação postural de endireitamento (RPE) ocorreu aos 2,3±0,8 minutos pós-injeção (MPI), observando-se início da anestesia aos 4,4±2,7 MPI. Miorrelaxamento e analgesia foram considerados excelentes em todos os momentos da avaliação. Reações conscientes foram observadas aos 78,7±22,2 MPI, o retorno da RPE ocorreu aos 101±18 MPI, e os animais voltaram à ambulação normal aos 137,0±31,0 MPI. Os valores médios dos parâmetros fisiológicos mensurados a cada 10 minutos entre 10 e 50 MPI foram 152,2 batimentos por minuto para frequência cardíaca, 66,4 movimentos por minuto para frequência respiratória, 39,2oC para temperatura retal, 86,2% para saturação parcial de oxigênio e 14,6mmHg para pressão arterial sistólica. Nesses tempos, observou-se ritmo sinusal no eletrocardiograma, e não foram observadas reações adversas.(AU)
Subject(s)
Animals , Body Temperature , Procyonidae/physiology , Respiratory Rate , Heart Rate , Anesthesia/veterinary , Tiletamine/analysis , Zolazepam/analysis , Anesthetics, Combined/analysis , Animals, Wild/physiologyABSTRACT
Resumen Introducción: Las personas con diabetes e hipertensión experimentan con mayor frecuencia sintomatología depresiva, lo cual contribuye a un inadecuado automanejo de la enfermedad, que implica tareas como: la toma de la medicación, asistir a las consultas médicas, el conocimiento de signos y síntomas, además de la toma de decisiones. Objetivo: Por lo anterior, el objetivo de este trabajo es identificar la relación entre automanejo en general y sus dimensiones con síntomas depresivos en personas con diabetes e hipertensión. Método: Estudio transversal-correlacional con n=205 pacientes con diagnóstico de diabetes (100) e hipertensión (105). Muestreo no probabilístico por conveniencia. Se utilizó la estadística descriptiva y r de Pearson. Se aplicaron los instrumentos Partners in Health (PIH) y The Patient Health Questionnaire (PHQ-8). Resultados: Se encontró correlación estadísticamente significativa entre la sintomatología depresiva y el automanejo (r=-0.308 ρ<0.001). Discusión y Conclusiones: Se concluye que la sintomatología depresiva se relaciona con el automanejo de la enfermedad de la siguiente manera: a mayor automanejo menor sintomatología de depresión, o a mayor sintomatología depresiva menor automanejo; dicha relación confirma que ambas variables se afectan mutuamente y/o mantienen una relación estrecha.
Abstract Introduction: Persons with diabetes and hypertension frequently suffer from depression as well, a situation which contributes to an inadequate management of the condition in terms of medication, medical consultations, signs, and decision making. Objective: To identify the relationship between general self-management and depression symptoms in persons with diabetes and hypertension. Method: This is a transversal and correlational study with a sample of 205 patients, 100 with a main diagnosis of diabetes, and 105 with a main diagnosis of hypertension. The sampling process was non-probabilistic and by convenience. Descriptive statistics, including Pearson's r were calculated. The Partners in Health (PIH) and Patient Health Questionnaire (PHQ-8) instruments were administered. Results: A statistically significant correlation between depression symptoms and diabetes and hypertension self-management was found (r=-0.308 ρ<0.001). Discussion and conclusions: Depression symptoms were related to how diabetes and hypertension are self-managed in a way that, the more self-management, the less depression symptoms, or the more depression symptoms, the less self-management.
Resumo Introdução: As pessoas com diabetes e hipertensão experimentam com maior frequência a sintomatologia depressiva, o qual contribui a um inadequado automanejo da doença, que envolve tarefas como: a toma da medicação, assistir às consultas médicas, o conhecimento de signos e sintomas, além da toma de decisões. Objetivo: Pelo anterior, o objetivo deste trabalho é identificar a relação entre automanejo em geral e suas dimensões com sintomas depressivos em pessoas com diabetes e hipertensão. Método: Estudo transversal-correlacional com n=205 pacientes com diagnóstico de diabetes (100) e hipertensão (105). Amostragem não probabilística por conveniência. Utilizou-se a estatística descritiva e r de Pearson. Aplicaram-se os instrumentos Partners in Health (PIH) e The Patient Health Questionnaire (PHQ-8). Resultados: Encontrou-se correlação estatisticamente significativa entre a sintomatologia depressiva e o automanejo (r=-0.308 ρ<0.001). Discussão e Conclusões: Conclui-se que a sintomatologia depressiva relaciona-se com o automanejo da doença da seguinte maneira: a maior automanejo, menor sintomatologia de depressão, ou a maior sintomatologia depressiva, menor automanejo; esta relação confirma que ambas variáveis afetam-se mutuamente e/ou mantem uma relação estreita.
ABSTRACT
RESUMEN Introducción: La programación adecuada de los implantes cocleares permiten lograr niveles de estimulación auditivos óptimos. Se realiza de forma individualizada, siendo la detección del umbral de confort ideal un desafío. Se ha descrito la utilidad de los potenciales auditivos del tronco encefálico eléctrico (ePEATC) y el reflejo eléctrico estapedial (eREE) para este propósito. Objetivo: Determinar la posibilidad de realizar ePEATC y eREE en pacientes adultos y pediátricos con implantes cocleares, y evaluar cambios en la programación de los implantes cocleares luego de las mediciones objetivas. Material y método: Se realizó un estudio prospectivo, descriptivo, de pacientes con implante coclear marca MED-EL®, separando los pacientes en dos grupos: el grupo adulto (n =5) y el grupo pediátrico (n =5). Todos los pacientes incluidos presentaron más de 6 meses de encendido del implante. Se evaluaron variables epidemiológicas y tiempo de encendido del implante. Se realizó una otoscopía, prueba básica de funcionamiento del implante, y las mediciones objetivas eléctricas (ePEATC, eREE). Con estos resultados se ajustó el umbral de confort. Resultados: El tiempo promedio de encendido del implante en el grupo adulto fue de 27 meses, y 30 meses en el grupo pediátrico. El ePEATC requiere más tiempo y cooperación al compararlo con eREE. Luego de estas evaluaciones objetivas, fue necesario el ajuste del umbral de confort en tres pacientes adultos, y en dos pacientes pediátricos. Fue necesario realizar una audiometría de campo libre para estimar el umbral de confort en dos pacientes pediátricos que no presentaron respuesta en eREE. Conclusión: Fue posible realizar estas mediciones objetivas en pacientes adultos y pediátricos, siendo mejor tolerado y requiriendo menos tiempo, el eREE.
ABSTRACT Introduction: Mapping a cochlear implant allows for adjusting ideal electrical stimulation limits. It is an individualized process and detecting the most comfortable loudness level can be challenging. The use of electrically evoked auditory brainstem response (ePEATC) and electrically evoked stapedius reflex thresholds (eREE) have been considered for this purpose. Aim: To determine the feasibility of performing ePEATC and eREE on adult and pediatric patients with a cochlear implant, and to evaluate changes in programming following these objective measures. Material and method: A prospective, descriptive study was completed, of patients with MED-EL® cochlear implants, separating patients into two groups: adults (n=5) and children (n=5). All of the patients included had their implants activated for 6 months or longer. Epidemiological variables and duration of implant activation were evaluated. Otoscopy, a basic implant functioning evaluation, and objective measures (ePEATC, eREE) were performed. With these results, comfortable loudness levels were adjusted. Results: Average duration of implant activation was 27 months and 30 months, for adults and children respectively. Performing ePEATC required more time and cooperation as compared to eREE. Following the objective measures, adjustment of the comfortable loudness levels was required for three adult and two pediatric patients. Sound field audiometry was necessary for two pediatric patients in order to estimate the comfortable loudness levels because the eREE responses were absent. Conclusions: It is feasible to perform these objective measures for both adult and pediatric patients, with eREE requiring less time and being better tolerated by patients.
Subject(s)
Humans , Male , Female , Child, Preschool , Child , Adult , Middle Aged , Young Adult , Cochlear Implants , Cochlear Implantation/methods , Reflex, Acoustic , Audiometry , Telemetry , Prospective Studies , Evoked Potentials, Auditory, Brain Stem , Health Services ProgrammingABSTRACT
Increasing levels of anthelmintic resistance observed in equine cyathostomin parasites have led to recommendations of selective anthelmintic treatment strategies to lower the selection pressure favoring resistant populations. This principle is based on determining strongyle fecal egg counts from all herd members, and treating those exceeding a predetermined treatment cutoff. However, epidemiological information is lacking from horses kept under tropical conditions, where parasite burdens may be of a different composition and magnitude compared to those of horses kept under temperate climate conditions. The aim of the present work was to characterize the strongylid fauna in horses kept in tropical Camagüey, Cuba and identify risk factors associated with strongylid and ascarid egg counts. A total of 396 horses from eight different establishments were included in the study. Coprocultures revealed that Strongylus vulgaris and cyathostomins, sensu lato, were detected in all of those establishments. Prevalence and mean value of strongylid eggs per gram of feces were 97% and 1436, respectively. Eggs of Parascaris spp. were observed in 10% of horses. A multivariate mixed linear model identified sex (p=0.022), month (p=0.044), operation type (p=0.037) and time since last deworming (p<0.001) to be significantly associated in with the magnitude of strongylid fecal egg counts. A multivariate logistic regression identified horses less than two years of age (p=0.010) and horses not receiving anthelmintic treatment (p<0.001) to be significantly more likely to harbor Parascaris spp. parasites. The high magnitude and prevalence of strongylid fecal egg counts observed and the common occurrence of S. vulgaris suggest that strongylid parasite burdens are substantially different from those typically observed in managed equines kept under more temperate conditions.
Subject(s)
Feces/parasitology , Helminthiasis, Animal/parasitology , Helminths/physiology , Horse Diseases/parasitology , Parasite Egg Count/veterinary , Animals , Anthelmintics/administration & dosage , Anthelmintics/therapeutic use , Cuba/epidemiology , Drug Resistance , Female , Helminthiasis, Animal/drug therapy , Helminthiasis, Animal/epidemiology , Helminths/drug effects , Horse Diseases/drug therapy , Horse Diseases/epidemiology , Horses , Male , Prevalence , Risk FactorsABSTRACT
Os quatis são mamíferos carnívoros da família Procyonidae, são animais onívoros, encontrados nas Américas do Norte, Central e Sul, sendo amplamente distribuídos no Brasil. O objetivo deste trabalho é analisar as alterações nos parâmetros sanguíneos de duas diferentes populações de quatis (Nasua nasua), da região oeste do Paraná, e avaliar a qualidade de vida e a interferência antrópica nos hábitos alimentares desses animais. A análise sorológica foi realizada em duas diferentes populações de quatis (Nasua nasua) que habitam duas unidades de conservação em regiões distintas no município de Foz do Iguaçu. Em uma das populações, foram visualizados cerca de cinquenta indivíduos, os quais se revelam em exposição direta aos seres humanos, e outra população menor, em torno de trinta indivíduos, os quais não possuem exposição direta aos seres humanos, o que, por sua vez, revelou importantes indicativos da qualidade de vida e de saúde desses animais. Foram realizadas avaliações bioquímicas do soro sanguíneo de 10 quatis adultos; cinco animais do grupo 1, população exposta aos seres humanos, e cinco animais do grupo 2, população com menor exposição. Com os resultados obtidos, foram feitas as comparações dos valores bioquímicos entre os grupos e com os valores de referência pesquisados na literatura. Os exames bioquímicos revelaram alterações significativas nos níveis de glicose e proteínas totais e alterações no nível plasmático de triglicerídeos nos quatis capturados na população em contado direto com seres humanos. Conclui-se que a saúde dos animais que possuem exposição direta com seres humanos está sendo afetada pelo consumo de uma dieta rica em carboidratos e gorduras, oriunda de alimentos industrializados fornecidos pelos turistas.(AU)
The coatis, carnivorous mammals of the Procyonidae family, are omnivorous animals, found in North, Central and South America and are widely distributed in Brazil. The objective of this study was to analyze changes in blood parameters in two different populations of coatis (Nasua nasua), of the western region of Paraná, and to evaluate the quality of life and the human interference in eating habits of these animals. Serologic analysis was performed in two different populations of coatis (Nasua nasua) inhabiting two conservation units in different areas in the city of Foz do Iguaçu. In one population, approximately fifty individuals were visualized, revealing themselves in direct exposure to humans as well as another minor population of about thirty individuals, which have no direct exposure to humans, which revealed important indicatives of the quality of life and health of these animals. Biochemical assessments of ten adults coatis serum were perfomred, five animals in group 1, population exposed to humans and five animals of the group 2, population less exposed. With the obtained results, comparisons were made between the groups' biochemical values and the reference values found in the literature. Biochemical tests revealed significant changes in glucose levels and total protein and changes in plasma levels of triglycerides in coatis captured in the population in direct contact with humans. It follows that the health of animals that have direct exposure to humans is being affected by the consumption of a diet high in carbohydrates and fats, coming from processed foods provided by tourists.(AU)
Subject(s)
Animals , Procyonidae/blood , Blood Chemical Analysis/veterinary , Diet, High-Fat/veterinary , Serologic Tests/veterinary , Animals, Wild/bloodABSTRACT
Os quatis são mamíferos carnívoros da família Procyonidae, são animais onívoros, encontrados nas Américas do Norte, Central e Sul, sendo amplamente distribuídos no Brasil. O objetivo deste trabalho é analisar as alterações nos parâmetros sanguíneos de duas diferentes populações de quatis (Nasua nasua), da região oeste do Paraná, e avaliar a qualidade de vida e a interferência antrópica nos hábitos alimentares desses animais. A análise sorológica foi realizada em duas diferentes populações de quatis (Nasua nasua) que habitam duas unidades de conservação em regiões distintas no município de Foz do Iguaçu. Em uma das populações, foram visualizados cerca de cinquenta indivíduos, os quais se revelam em exposição direta aos seres humanos, e outra população menor, em torno de trinta indivíduos, os quais não possuem exposição direta aos seres humanos, o que, por sua vez, revelou importantes indicativos da qualidade de vida e de saúde desses animais. Foram realizadas avaliações bioquímicas do soro sanguíneo de 10 quatis adultos; cinco animais do grupo 1, população exposta aos seres humanos, e cinco animais do grupo 2, população com menor exposição. Com os resultados obtidos, foram feitas as comparações dos valores bioquímicos entre os grupos e com os valores de referência pesquisados na literatura. Os exames bioquímicos revelaram alterações significativas nos níveis de glicose e proteínas totais e alterações no nível plasmático de triglicerídeos nos quatis capturados na população em contado direto com seres humanos. Conclui-se que a saúde dos animais que possuem exposição direta com seres humanos está sendo afetada pelo consumo de uma dieta rica em carboidratos e gorduras, oriunda de alimentos industrializados fornecidos pelos turistas.(AU)
The coatis, carnivorous mammals of the Procyonidae family, are omnivorous animals, found in North, Central and South America and are widely distributed in Brazil. The objective of this study was to analyze changes in blood parameters in two different populations of coatis (Nasua nasua), of the western region of Paraná, and to evaluate the quality of life and the human interference in eating habits of these animals. Serologic analysis was performed in two different populations of coatis (Nasua nasua) inhabiting two conservation units in different areas in the city of Foz do Iguaçu. In one population, approximately fifty individuals were visualized, revealing themselves in direct exposure to humans as well as another minor population of about thirty individuals, which have no direct exposure to humans, which revealed important indicatives of the quality of life and health of these animals. Biochemical assessments of ten adults coatis serum were perfomred, five animals in group 1, population exposed to humans and five animals of the group 2, population less exposed. With the obtained results, comparisons were made between the groups' biochemical values and the reference values found in the literature. Biochemical tests revealed significant changes in glucose levels and total protein and changes in plasma levels of triglycerides in coatis captured in the population in direct contact with humans. It follows that the health of animals that have direct exposure to humans is being affected by the consumption of a diet high in carbohydrates and fats, coming from processed foods provided by tourists.(AU)
Subject(s)
Animals , Blood Chemical Analysis/veterinary , Diet, High-Fat/veterinary , Procyonidae/blood , Animals, Wild/blood , Serologic Tests/veterinaryABSTRACT
There is evidence that the left hemisphere is more competent for motor control than the right hemisphere. This study investigated whether this hemispheric asymmetry is expressed in the latency/duration of sequential responses performed by the left and/or right hands. Thirty-two right-handed young adults (16 males, 16 females; 18-25 years old) were tested in a simple or choice reaction time task. They responded to a left and/or right visual target by moving their left and/or right middle fingers between two keys on each side of the midline. Right hand reaction time did not differ from left hand reaction time. Submovement times were longer for the right hand than the left hand when the response was bilateral. Pause times were shorter for the right hand than the left hand, both when the responses were unilateral or bilateral. Reaction time results indicate that the putatively more efficient response preparation by the left hemisphere motor mechanisms is not expressed behaviorally. Submovement time and pause time results indicate that the putatively more efficient response execution by the left hemisphere motor mechanisms is expressed behaviorally. In the case of the submovements, the less efficient motor control of the left hand would be compensated by a more intense attention to this hand.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Young Adult , Attention/physiology , Functional Laterality/physiology , Hand/physiology , Orientation/physiology , Psychomotor Performance/physiology , Reaction Time/physiologyABSTRACT
There is evidence that the left hemisphere is more competent for motor control than the right hemisphere. This study investigated whether this hemispheric asymmetry is expressed in the latency/duration of sequential responses performed by the left and/or right hands. Thirty-two right-handed young adults (16 males, 16 females; 18-25 years old) were tested in a simple or choice reaction time task. They responded to a left and/or right visual target by moving their left and/or right middle fingers between two keys on each side of the midline. Right hand reaction time did not differ from left hand reaction time. Submovement times were longer for the right hand than the left hand when the response was bilateral. Pause times were shorter for the right hand than the left hand, both when the responses were unilateral or bilateral. Reaction time results indicate that the putatively more efficient response preparation by the left hemisphere motor mechanisms is not expressed behaviorally. Submovement time and pause time results indicate that the putatively more efficient response execution by the left hemisphere motor mechanisms is expressed behaviorally. In the case of the submovements, the less efficient motor control of the left hand would be compensated by a more intense attention to this hand.
Subject(s)
Attention/physiology , Functional Laterality/physiology , Hand/physiology , Orientation/physiology , Psychomotor Performance/physiology , Reaction Time/physiology , Adolescent , Adult , Female , Humans , Male , Young AdultABSTRACT
BACKGROUND: Antibiotic resistance is an increasing problem, particularly in countries where antibiotic use is frequently not controlled. The aim of this study was to analyse the prevalence of the molecular mechanisms of quinolone-resistance in E. coli isolated from faeces of healthy Peruvian children or those presenting diarrhoea. METHODS: The presence of target mutations, transferable quinolone-resistance mechanisms and the role of Phe-Arg-ß-Naphtylamyde inhibitible efflux pumps were studied in 96 Escherichia coli (46 diarrheogenic and 50 non-diarrheogenic) isolates exhibiting resistance or diminished susceptibility to quinolones. RESULTS: The most resistant phenotype, Nal(R) and Cip(R), was most frequently present in isolates of healthy children. The distribution of quinolone resistance mechanisms between diarrheogenic (DEC) and commensal (non DEC) isolates was equitable, although the aac(6')Ib-cr gene was mainly detected in DEC isolates: 17 (34%) vs non DEC isolates nine (20%). QnrB was present in five (10%) DEC vs three (6%) non DEC isolates. CONCLUSIONS: Point mutations in gyrA and parC genes play a relevant role in quinolone resistance acquisition and highlight the role of efflux pumps also. This study provides knowledge about the molecular mechanisms involved in quinolone resistance in isolates in a non exposed population under high community antibiotic pressure.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Quinolones/pharmacology , Bacterial Proteins/genetics , Ciprofloxacin/pharmacology , Dipeptides/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli/genetics , Escherichia coli/isolation & purification , Escherichia coli Infections/drug therapy , Escherichia coli Infections/epidemiology , Escherichia coli Proteins/genetics , Feces/microbiology , Female , Humans , Infant , Male , Microbial Sensitivity Tests , Nalidixic Acid/pharmacology , Peru/epidemiology , PrevalenceABSTRACT
Some results in the literature suggest that crossmodal attention is very sensitive to the features of the experimental protocol. The current work examined the possible contribution of the asynchrony between the onset of the cue and the target (SOA) and the kind of task performed by the observer to the manifestation of crossmodal attentional effect. In a first experiment, a target (Gabor patch), whose spatial frequency had to be discriminated, was presented 133 or 159 ms after an auditory cue, in a close location on the same side or in a distant location on the opposite side. The crossmodal attentional effect was observed only for the 159 ms SOA. In a second experiment, the SOA was again 133 ms, but the location of the target had to be discriminated, instead of its spatial frequency. A crossmodal attentional effect was observed. The results of these two experiments indicate that crossmodal attentional effect depends on the SOA and the task. It takes longer to develop when the task requires the discrimination of the spatial frequency of the target than the discrimination of its location.
Subject(s)
Attention/physiology , Psychomotor Performance/physiology , Reaction Time/physiology , Acoustic Stimulation , Cues , Female , Humans , Male , Orientation/physiology , Photic Stimulation , Space Perception/physiology , Young AdultABSTRACT
The occurrence of a weak auditory warning stimulus increases the speed of the response to a subsequent visual target stimulus that must be identified. This facilitatory effect has been attributed to the temporal expectancy automatically induced by the warning stimulus. It has not been determined whether this results from a modulation of the stimulus identification process, the response selection process or both. The present study examined these possibilities. A group of 12 young adults performed a reaction time location identification task and another group of 12 young adults performed a reaction time shape identification task. A visual target stimulus was presented 1850 to 2350 ms plus a fixed interval (50, 100, 200, 400, 800, or 1600 ms, depending on the block) after the appearance of a fixation point, on its left or right side, above or below a virtual horizontal line passing through it. In half of the trials, a weak auditory warning stimulus (S1) appeared 50, 100, 200, 400, 800, or 1600 ms (according to the block) before the target stimulus (S2). Twelve trials were run for each condition. The S1 produced a facilitatory effect for the 200, 400, 800, and 1600 ms stimulus onset asynchronies (SOA) in the case of the side stimulus-response (S-R) corresponding condition, and for the 100 and 400 ms SOA in the case of the side S-R non-corresponding condition. Since these two conditions differ mainly by their response selection requirements, it is reasonable to conclude that automatic temporal expectancy influences the response selection process.
Subject(s)
Adult , Female , Humans , Male , Young Adult , Attention/physiology , Pattern Recognition, Visual/physiology , Photic Stimulation/methods , Reaction Time/physiology , Acoustic Stimulation/methodsABSTRACT
The occurrence of a weak auditory warning stimulus increases the speed of the response to a subsequent visual target stimulus that must be identified. This facilitatory effect has been attributed to the temporal expectancy automatically induced by the warning stimulus. It has not been determined whether this results from a modulation of the stimulus identification process, the response selection process or both. The present study examined these possibilities. A group of 12 young adults performed a reaction time location identification task and another group of 12 young adults performed a reaction time shape identification task. A visual target stimulus was presented 1850 to 2350 ms plus a fixed interval (50, 100, 200, 400, 800, or 1600 ms, depending on the block) after the appearance of a fixation point, on its left or right side, above or below a virtual horizontal line passing through it. In half of the trials, a weak auditory warning stimulus (S1) appeared 50, 100, 200, 400, 800, or 1600 ms (according to the block) before the target stimulus (S2). Twelve trials were run for each condition. The S1 produced a facilitatory effect for the 200, 400, 800, and 1600 ms stimulus onset asynchronies (SOA) in the case of the side stimulus-response (S-R) corresponding condition, and for the 100 and 400 ms SOA in the case of the side S-R non-corresponding condition. Since these two conditions differ mainly by their response selection requirements, it is reasonable to conclude that automatic temporal expectancy influences the response selection process.
Subject(s)
Attention/physiology , Pattern Recognition, Visual/physiology , Photic Stimulation/methods , Reaction Time/physiology , Acoustic Stimulation/methods , Adult , Female , Humans , Male , Young AdultABSTRACT
This study investigated the influence of cueing on the performance of untrained and trained complex motor responses. Healthy adults responded to a visual target by performing four sequential movements (complex response) or a single movement (simple response) of their middle finger. A visual cue preceded the target by an interval of 300, 1000, or 2000 ms. In Experiment 1, the complex and simple responses were not previously trained. During the testing session, the complex response pattern varied on a trial-by-trial basis following the indication provided by the visual cue. In Experiment 2, the complex response and the simple response were extensively trained beforehand. During the testing session, the trained complex response pattern was performed in all trials. The latency of the untrained and trained complex responses decreased from the short to the medium and long cue-target intervals. The latency of the complex response was longer than that of the simple response, except in the case of the trained responses and the long cue-target interval. These results suggest that the preparation of untrained complex responses cannot be completed in advance, this being possible, however, for trained complex responses when enough time is available. The duration of the 1st submovement, 1st pause and 2nd submovement of the untrained and the trained complex responses increased from the short to the long cue-target interval, suggesting that there is an increase of online programming of the response possibly related to the degree of certainty about the moment of target appearance.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Young Adult , Cues , Conditioning, Psychological/physiology , Movement/physiology , Photic Stimulation/methods , Reaction Time/physiologyABSTRACT
This study investigated the influence of cueing on the performance of untrained and trained complex motor responses. Healthy adults responded to a visual target by performing four sequential movements (complex response) or a single movement (simple response) of their middle finger. A visual cue preceded the target by an interval of 300, 1000, or 2000 ms. In Experiment 1, the complex and simple responses were not previously trained. During the testing session, the complex response pattern varied on a trial-by-trial basis following the indication provided by the visual cue. In Experiment 2, the complex response and the simple response were extensively trained beforehand. During the testing session, the trained complex response pattern was performed in all trials. The latency of the untrained and trained complex responses decreased from the short to the medium and long cue-target intervals. The latency of the complex response was longer than that of the simple response, except in the case of the trained responses and the long cue-target interval. These results suggest that the preparation of untrained complex responses cannot be completed in advance, this being possible, however, for trained complex responses when enough time is available. The duration of the 1st submovement, 1st pause and 2nd submovement of the untrained and the trained complex responses increased from the short to the long cue-target interval, suggesting that there is an increase of online programming of the response possibly related to the degree of certainty about the moment of target appearance.
Subject(s)
Conditioning, Psychological/physiology , Cues , Movement/physiology , Photic Stimulation/methods , Reaction Time/physiology , Adolescent , Adult , Female , Humans , Male , Young AdultABSTRACT
There is evidence that automatic visual attention favors the right side. This study investigated whether this lateral asymmetry interacts with the right hemisphere dominance for visual location processing and left hemisphere dominance for visual shape processing. Volunteers were tested in a location discrimination task and a shape discrimination task. The target stimuli (S2) could occur in the left or right hemifield. They were preceded by an ipsilateral, contralateral or bilateral prime stimulus (S1). The attentional effect produced by the right S1 was larger than that produced by the left S1. This lateral asymmetry was similar between the two tasks suggesting that the hemispheric asymmetries of visual mechanisms do not contribute to it. The finding that it was basically due to a longer reaction time to the left S2 than to the right S2 for the contralateral S1 condition suggests that the inhibitory component of attention is laterally asymmetric.
Subject(s)
Attention/physiology , Discrimination, Psychological/physiology , Form Perception/physiology , Functional Laterality/physiology , Visual Perception/physiology , Adult , Humans , Male , Photic Stimulation/methods , Reaction Time/physiology , Task Performance and Analysis , Young AdultABSTRACT
We recently demonstrated that automatic attention favors the right side of space and, in the present study, we investigated whether voluntary attention also favors this side. Six reaction time experiments were conducted. In each experiment, 12 new 18-25-year-old male right-handed individuals were tested. In Experiments 1, 2, 3 (a, b) and 4 (a, b), tasks with increasing attentional demands were used. In Experiments 1, 2, 3a, and 4a, attention was oriented to one or both sides by means of a central spatially informative visual cue. A left or right side visual target appeared 100, 300, or 500 ms later. Attentional effects were observed in the four experiments. In Experiments 2, 3a and 4a, these effects were greater when the cue indicated the right side than when it indicated the left side (respectively: 16 ± 10 and 44 ± 6 ms, P = 0.015, for stimulus onset asynchrony of 500 ms in Experiment 2; 38 ± 10 and 70 ± 7 ms, P = 0.011, for Experiment 3a, and 23 ± 11 and 61 ± 10 ms, P = 0.009, for Experiment 4a). In Experiments 3b and 4b, the central cue pointed to both sides and was said to be non-relevant for task performance. In these experiments right and left reaction times did not differ. The most conservative interpretation of the present findings is that voluntary attention orienting favors the right side of space, particularly when a difficult task has to be performed.
Subject(s)
Adolescent , Adult , Humans , Male , Young Adult , Attention/physiology , Functional Laterality/physiology , Orientation/physiology , Reaction Time/physiology , Space Perception/physiology , Photic Stimulation , Young AdultABSTRACT
We recently demonstrated that automatic attention favors the right side of space and, in the present study, we investigated whether voluntary attention also favors this side. Six reaction time experiments were conducted. In each experiment, 12 new 18-25-year-old male right-handed individuals were tested. In Experiments 1, 2, 3 (a, b) and 4 (a, b), tasks with increasing attentional demands were used. In Experiments 1, 2, 3a, and 4a, attention was oriented to one or both sides by means of a central spatially informative visual cue. A left or right side visual target appeared 100, 300, or 500 ms later. Attentional effects were observed in the four experiments. In Experiments 2, 3a and 4a, these effects were greater when the cue indicated the right side than when it indicated the left side (respectively: 16 +/- 10 and 44 +/- 6 ms, P = 0.015, for stimulus onset asynchrony of 500 ms in Experiment 2; 38 +/- 10 and 70 +/- 7 ms, P = 0.011, for Experiment 3a, and 23 +/- 11 and 61 +/- 10 ms, P = 0.009, for Experiment 4a). In Experiments 3b and 4b, the central cue pointed to both sides and was said to be non-relevant for task performance. In these experiments right and left reaction times did not differ. The most conservative interpretation of the present findings is that voluntary attention orienting favors the right side of space, particularly when a difficult task has to be performed.
Subject(s)
Attention/physiology , Functional Laterality/physiology , Orientation/physiology , Reaction Time/physiology , Space Perception/physiology , Adolescent , Adult , Humans , Male , Photic Stimulation , Young AdultABSTRACT
OBJETIVO: O hemisfério esquerdo é dominante para o controle motor e o direito para a orientação espacial. Este estudo visou testar as hipóteses de que a lesão à esquerda causa maior prejuízo da movimentação voluntária e a lesão à direita resulta em perda na atenção espacial e no controle postural. Indivíduos com lesão à esquerda foram comparados com indivíduos com lesão à direita, com relação ao comprometimento inicial e recuperação três meses pós-lesão. MATERIAIS E MÉTODOS: Vinte e dois indivíduos destros com lesão isquêmica no território da artéria cerebral média (11 à esquerda e 11 à direita) foram avaliados mensalmente nos três primeiros meses pós-lesão em termos de sensibilidade, tônus, força, postura, marcha, independência funcional e atenção espacial. RESULTADOS: Com relação ao comprometimento inicial, não houve diferença na sensibilidade, tônus, força, postura e atenção dos grupos. O grupo com lesão à esquerda apresentou pior desempenho inicial nos testes de marcha e de independência funcional. Com relação à taxa de recuperação, não houve diferenças na sensibilidade, tônus, força, postura, atenção e independência funcional dos dois grupos. Porém, a taxa de recuperação da marcha do grupo com lesão à esquerda foi inferior à do outro grupo. CONCLUSÕES: Foi confirmada a hipótese de que a lesão à esquerda causa maior comprometimento da movimentação voluntária, representada pela marcha e independência funcional, que a lesão à direita. Não foi obtida, no entanto, evidência de que a lesão à direita compromete de modo mais intenso a atenção espacial e a manutenção da postura que a lesão à esquerda.
OBJECTIVE: The left hemisphere is supposed to be dominant for motor control and the right hemisphere dominant for spatial orientation. This study aimed to test the hypothesis that left-side lesions cause greater impairment of voluntary movement, while right-side lesions cause loss of spatial attention loss and postural control. Individuals with left-side lesions were compared with individuals with right-side lesions, in relation to initial impairment and recovery three months after their stroke. METHODS: Twenty-two right-handed individuals with an ischemic lesion in the area of the middle cerebral artery (11 on the left side and 11 on the right side) were assessed monthly, for the first three months after their stroke, in terms of sensitivity, tonus, posture, gait, functional independence and spatial attention. RESULTS: In relation to the initial impairment, there was no difference in sensitivity, tonus, strength, posture and spatial attention between the groups. The left-side lesion group presented worse initial performance in gait and functional independence tests. In relation to the recovery rate, there were no differences in sensitivity, tonus, strength, posture, spatial attention or functional independence between the two groups. However, the gait recovery rate in the left-side lesion group was slower than in the other group. CONCLUSIONS: The hypothesis that left-side lesions cause greater impairment of voluntary movement (represented by gait and functional independence) than do right-side lesions was supported. However, no evidence that right-side lesions cause greater impairment of spatial attention and posture maintenance than do left-side lesions was found.
Subject(s)
Exercise , Functional Laterality , Gait , Rehabilitation , StrokeABSTRACT
A long-standing debate in the literature is whether attention can form two or more independent spatial foci in addition to the well-known unique spatial focus. There is evidence that voluntary visual attention divides in space. The possibility that this also occurs for automatic visual attention was investigated here. Thirty-six female volunteers were tested. In each trial, a prime stimulus was presented in the left or right visual hemifield. This stimulus was characterized by the blinking of a superior, middle or inferior ring, the blinking of all these rings, or the blinking of the superior and inferior rings. A target stimulus to which the volunteer should respond with the same side hand or a target stimulus to which she should not respond was presented 100 ms later in a primed location, a location between two primed locations or a location in the contralateral hemifield. Reaction time to the positive target stimulus in a primed location was consistently shorter than reaction time in the horizontally corresponding contralateral location. This attentional effect was significantly smaller or absent when the positive target stimulus appeared in the middle location after the double prime stimulus. These results suggest that automatic visual attention can focus on two separate locations simultaneously, to some extent sparing the region in between.
Subject(s)
Attention/physiology , Functional Laterality/physiology , Space Perception/physiology , Visual Fields/physiology , Adult , Female , Humans , Photic Stimulation , Reaction Time/physiologyABSTRACT
A long-standing debate in the literature is whether attention can form two or more independent spatial foci in addition to the well-known unique spatial focus. There is evidence that voluntary visual attention divides in space. The possibility that this also occurs for automatic visual attention was investigated here. Thirty-six female volunteers were tested. In each trial, a prime stimulus was presented in the left or right visual hemifield. This stimulus was characterized by the blinking of a superior, middle or inferior ring, the blinking of all these rings, or the blinking of the superior and inferior rings. A target stimulus to which the volunteer should respond with the same side hand or a target stimulus to which she should not respond was presented 100 ms later in a primed location, a location between two primed locations or a location in the contralateral hemifield. Reaction time to the positive target stimulus in a primed location was consistently shorter than reaction time in the horizontally corresponding contralateral location. This attentional effect was significantly smaller or absent when the positive target stimulus appeared in the middle location after the double prime stimulus. These results suggest that automatic visual attention can focus on two separate locations simultaneously, to some extent sparing the region in between.