Neural Circuit Mechanisms Involved in Animals' Detection of and Response to Visual Threats / 神经科学通报·英文版

Evading or escaping from predators is one of the most crucial issues for survival across the animal kingdom. The timely detection of predators and the initiation of appropriate fight-or-flight responses are innate capabilities of the nervous system. Here we review recent progress in our understanding of innate visually-triggered defensive behaviors and the underlying neural circuit mechanisms, and a comparison among vinegar flies, zebrafish, and mice is included. This overview covers the anatomical and functional aspects of the neural circuits involved in this process, including visual threat processing and identification, the selection of appropriate behavioral responses, and the initiation of these innate defensive behaviors. The emphasis of this review is on the early stages of this pathway, namely, threat identification from complex visual inputs and how behavioral choices are influenced by differences in visual threats. We also briefly cover how the innate defensive response is processed centrally. Based on these summaries, we discuss coding strategies for visual threats and propose a common prototypical pathway for rapid innate defensive responses.

Cortical Mechanisms of Multisensory Linear Self-motion Perception / 神经科学通报·英文版

Accurate self-motion perception, which is critical for organisms to survive, is a process involving multiple sensory cues. The two most powerful cues are visual (optic flow) and vestibular (inertial motion). Psychophysical studies have indicated that humans and nonhuman primates integrate the two cues to improve the estimation of self-motion direction, often in a statistically Bayesian-optimal way. In the last decade, single-unit recordings in awake, behaving animals have provided valuable neurophysiological data with a high spatial and temporal resolution, giving insight into possible neural mechanisms underlying multisensory self-motion perception. Here, we review these findings, along with new evidence from the most recent studies focusing on the temporal dynamics of signals in different modalities. We show that, in light of new data, conventional thoughts about the cortical mechanisms underlying visuo-vestibular integration for linear self-motion are challenged. We propose that different temporal component signals may mediate different functions, a possibility that requires future studies.

Conceitos básicos de percepção de cena / Basic concepts of scene perception

A pesquisa sobre percepção de cenas é um esforço da comunidade científica em superar as dificuldades apresentadas ao estudo de estímulos complexos. As consistentes descobertas provaram a viabilidade do tema e encorajam uma abordagem mais holística e integrada nas investigações em percepção visual. Esse esforço e seus achados são, entretanto, pouco conhecidos pelos leitores em língua portuguesa e, até mesmo, entre alguns especialistas que se interessam pelo tema. O objetivo deste trabalho é fazer uma apresentação do campo, esboçar seu desenvolvimento, identificar suas principais questões e demonstrar sua pertinência e importância. Para isso, uma revisão seletiva de textos foi executada entre os autores que construíram os fundamentos da percepção de cenas. Ao concluir a leitura, espera-se que o leitor constate o papel relevante dos processos mnemônicos e do sujeito que observa no processo de captação visual do ambiente natural.

Scene perception research is a scientific community effort to overcome difficulties presented to the study of complex stimuli. Consistent findings support feasibility of the theme and encourage a more holistic and integrated approach to visual perception research. This effort and its findings are, however, poorly known by readers in Portuguese language, even among experts interested in the subject. The purpose of this paper is to introduce this field of research, outline its development, identify its main issues and demonstrate its relevance and importance. This task was accomplished by a selective review of papers from authors who built the foundations of scene perception. Upon completion of the reading, it is expected that the reader understands the relevant role of mnemonic processes and of the observer in the process of visual capture of natural environments.

Pictorial size perception in schizophrenia

In this study, we compared visual pictorial size perception between healthy volunteers (CG) and an experimental group (EG) of people diagnosed with schizophrenia. We have been using paintings by Salvador Dalí and Rorschach plates to estimate visual pictorial size perception. In this transversal, ex post facto, and quasi-experimental study, we observed differences between EG and CG. Schizophrenic in-patients perceived sizes about 1.3-fold greater than healthy volunteers (p=0.006), implying that pictorial size perception is altered in some way in schizophrenia. Considering the present and previous results, this measurement of diameter size of first pictorial perception may be a useful estimate of some aspects of perceptual alterations that may be associated with psychotic symptoms in prodromal and acute schizophrenic episodes and other related mental states. Eventually, this may help in preventing people from evolving to acute episodes.

Dependencia visual en otoneurología: consideraciones clínicas para la rehabilitación vestibular / Visual dependence in otoneurology: clinical considerations for vestibular rehabilitation

RESUMEN Los sistemas vestibular, visual y somatosensorial coordinan el control postural y se adaptan a las actividades cotidianas en diferentes contextos, sin embargo, cuando existe un cuadro clínico con sintomatología vestibular, las ponderaciones de estos sistemas cambian mayoritariamente al sistema visual, creando una dependencia visual. El cerebelo, que es el principal encargado de generar una compensación vestibular en casos de hipofunción vestibular, juega un rol destacado en el aprendizaje motor generando comportamientos adaptativos que se transforman en puntos claves en la rehabilitación vestibular. Este artículo pretende exponer lo que la literatura informa en relación a la dependencia visual en pacientes con hipofunción vestibular.

ABSTRACT The vestibular, visual and somatosensory systems coordinate postural control and adapt to daily activities in different contexts, however, when there is a clinical picture with vestibular symptoms, the weights of these systems change mainly to the visual system, creating a visual dependence. The cerebellum, which is the main responsible for generating vestibular compensation in cases of vestibular hypofunction, plays a prominent role in motor learning generating adaptive behaviors that become key points in vestibular rehabilitation. This article aims to expose what the literature reports in relation to visual dependence in patients with vestibular hypofunction.

Diferencias en procesamiento cerebral visual temprano en niños con trastorno del déficit de atención / Differences in early visual cerebral processing in children with attention deficit / hyperactivity disorders with predominance of no attention

Para evaluar los procesos atencionales a estímulos visuales que no requieren repuesta motora, se llevó a cabo un estudio con potenciales evocados a 17 niños con trastornos del déficit de atención/ hiperactividad (TDAH-I) con predominio inatento y a 15 controles de edades entre 7 y 11 años. Se analizó la latencia y localización de fuentes de los potenciales evocados visuales tempranos P100 y N100 durante la realización de una tarea oddball visual (20% rayas horizontales y 80% verticales) en que las rayas verticales no exigían respuesta motora. Los resultados indican que los niños con TDAH-I procesan la información visual que no requiere respuesta motora con un mayor aumento de la actividad cerebral y mediante la vía temporal ventral mientras que el grupo control lo hace mediante la vía parietal dorsal. Este proceso neurobiológico de procesamiento de la información visual vía temporal ventral de los niños con TDAH-I podría deberse a alteraciones en los procesos emocionales que influyen directamente en el reconocimiento visual o a un déficit en el control de los procesos atencionales por parte de la vía parietal dorsal.

To evaluate attentional processes to visual stimuli that do not require motor response, a study with evoked potentials was carried out on 17 children with attention deficit disorder predominantly inattentive (ADDH-I) and 15 controls between the ages of 7 and 11 years. The latency and localization of sources of the early visual evoked potentials P100 and N100 were analyzed during the performance of a visual oddball task (20% horizontal and 80% vertical lines) where the vertical lines did not require motor response. The results indicate that ADDH-I group process visual information that does not require motor response with a greater increase in brain activity and through the ventral temporal pathway, while the control group does so by means of the dorsal parietal stream. This neurobiological process of visual information processing by ventral temporal pathway of ADDH-I group could be due to alterations in emotional processes that directly influence visual recognition or as consequence of deficit in the control of attentional processes by the dorsal parietal pathway.

A power law study of the edge influence on the perceived filling-in brightness magnitude

Abstract: Background: Edge plays a special role in spatial perception and as well as in determining the brightness of a surface within borders. The aim of our study was to measure threshold brightness in different levels of edges thickness. Methods: Steven's power law for circles modulating in luminance was estimated for 30 subjects (mean age 24 years, SD 3.3, 13 female). Stimuli were presented on the iMac display using the 11-bit graphic board and consisted of two circles of 3° of visual angle, separated by 10°. We tested 7 levels of Michelson contrast: 7, 8, 10, 15, 26, 50, and 100. Three edges filtering were tested (0.3, 0.8, and 1.5° of smoothing). The subjects' task was to judge the brightness of the edge filtered circle compared with the circle of the hard edge which was considered the modulus and received an arbitrary level of 50, representing the amount of brightness perception. In each trial, the same contrast level was presented in both circles. Five judgments were performed for each contrast level in edge filtering. Results: We found an increase in the power law exponent as the increase of the edge filtering (for sigma of 0.3 = 0.43, sigma of 0.8 = 0.73, and sigma 1.5 = 0.97). All power function fitting had high correlation coefficients (r2 = .94, r2 = .95, r2 = .97, respectively to sigma 0.3, 0.8, and 1.5) passing to the model's adhesion criteria. Conclusions: There was a progressive distortion on the figure brightness perception as increasing the edge filtering suggesting the control of edges on the polarity of the overall brightness. Also, perceived brightness was increasingly veridical with increased filtering, approaching 1:1 correspondence at 1.5 sigmas. (AU)

Evaluación de habilidades perceptivo-cognitivas en deportistas universitarios / Evaluation of cognitive-perceptive abilities in university athletes

El objetivo de este estudio ha sido evaluar la habilidad perceptiva cognitiva de los deportistas seleccio-nados de la Universidad de Playa Ancha a través de una herramienta tecnológica de seguimiento de objetos múltiples dentro de un campo visual (Neurotracker). Se utilizó una metodología de carácter cuantitativo enmarcado dentro del paradigma positivista de tipo descriptivo. La muestra fue de 101 deportistas de diversas disciplinas y ambos sexos, todos escogidos a través del método de muestreo por conveniencia o selección intencionada. Los datos obtenidos fueron analizados a través de estadística descriptiva inferencial. Los resultados muestran que la clasificación del deporte (estructura abierta y estructura cerrada) influencia el rendimiento perceptivo-cognitivo del deportista, existiendo una estricta relación con las horas de entrenamiento. Ambas variables son directamente proporcional a los resultados y, se presentan diferencias significativas según sexo.

The objective of this study was to evaluate the cognitive-perceptive ability of selected athletes from Universidad Playa Ancha by means of a technological tracking tool for multiple objects within a visual field (Neurotracker). The researchers applied quantitative methods based on the positivist paradigm of descriptive type. The sample size consisted of 101 female and male athletes from various majors, all of whom were selected through the convenience sampling method. The data was analyzed using infe-rential descriptive statistics. The study results demonstrate that the sports classification (open struc-ture and closed structure) influences the perception/cognitive performance of the athletes, showing a strong relationship to the number of hours of athletic training. Both variables were found to be directly proportional to the results and there were significant differences based on sex/gender

Organic solvent exposure and contrast sensitivity: comparing men and women

The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity of 62.25±7.59% and ventilation of 0.69±0.46 m/s (a passive gas chromatography-based sampling method was used considering the microclimate variables). Visual CS was measured via the psychophysical method of two-alternative forced choice using vertical sinusoidal gratings with spatial frequencies of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd (cycles per degree) and an average luminance of 34.4 cd/m2. The results showed that visual CS was significantly lower (P<0.05) in the following groups: i) exposed men compared to unexposed men at frequencies of 0.2, 0.5, 1.0, and 2.0 cpd; ii) exposed women compared to unexposed women at a frequency of 5.0 cpd; and iii) exposed women compared to exposed men at a frequency of 0.5 cpd, even at exposures below the tolerance limit (300 ppm). These results suggest that the visual CS of exposed men was impaired over a wider range of spatial frequencies than that of exposed women. This difference may have been due to the higher body fat content of women compared to that of men, suggesting that body fat in women can serve as a protective factor against neurotoxic effects.

Subjective visual vertical after treatment of benign paroxysmal positional vertigo / Vertical visual subjetiva após tratamento da vertigem posicional paroxística benigna

Abstract Introduction: Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. Objective: To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. Methods: We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Results: Before repositioning maneuver, 9 patients (45.0%) had absolute values of the subjective visual vertical above the reference standard and 2 (10.0%) after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (p < 0.001). Conclusion: There is a reduction of the deviations of the subjective visual vertical, evaluated by the bucket test, immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo.

Resumo Introdução: A função do otólito pode ser estudada por meio de testes da vertical visual subjetiva, porque a inclinação da linha vertical além da faixa normal é um sinal de disfunção vestibular. A vertigem postural paroxística benigna é um distúrbio de um ou mais canais semicirculares labirínticos causado por frações de otólitos derivados da mácula utricular. Objetivo: Comparar a vertical visual subjetiva com o teste do balde antes e imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna. Método: Foram avaliados 20 pacientes. A posição estimada, onde uma linha de fluorescência dentro de um balde atingia a posição vertical, foi medida antes e imediatamente após a manobra de reposicionamento de partículas. Os dados foram tabulados e analisados estatisticamente. Resultados: Antes da manobra de reposicionamento, nove pacientes (45%) apresentaram valores absolutos de vertical visual subjetiva acima da referência padrão e dois (10%) depois da manobra; a média dos valores absolutos do desvio vertical foi significativamente mais baixa depois da intervenção (p < 0,001). Conclusão: Há uma redução dos desvios da vertical visual subjetiva, avaliada pelo teste do balde, imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna.

A elaboração de um instrumento para investigar o domínio da percepção dos contrastes mínimos na língua brasileira de sinais / Elaboration of an instrument to investigate the acquisition of minimal contrast perception in the Brazilian sign language

RESUMO Objetivo Elaborar um instrumento para verificar a percepção dos contrastes mínimos, mediante a utilização de pares de sinais, os quais apresentam oposições em relação a um dos parâmetros: configuração de mão, locação de mão, movimento de mão e orientação de mão. Método Realizou-se um levantamento dos pares mínimos e foram confeccionadas figuras por um profissional das artes visuais, essas foram dispostas em três colunas, podendo ser iguais ou diferentes. Realizou-se a gravação de um vídeo contendo uma intérprete que realizava dois sinais por vez, para que o sujeito que fosse avaliado pudesse visualizá-los e apontar, nas figuras, quais sinais foram solicitados. Os julgadores analisaram os pares, referindo se estavam adequados, podendo realizar modificações ou solicitar que o par mínimo fosse retirado. Os julgadores verificaram ainda se as figuras estavam claras e se eram do vocabulário de crianças. Resultados A análise de concordância realizada entre os avaliadores mostrou resultado significativo para o critério julgado como 'não é par mínimo'. Foram retirados do instrumento 13 itens, pois variavam em mais de um parâmetro, configurando, dessa forma, pares análogos e não pares mínimos. Foram modificados 16 pares e acrescentados sete que variavam quanto ao parâmetro orientação, configurando um total de 35 pares mínimos na versão final do instrumento. Conclusão O objetivo de elaborar um instrumento de percepção de contrastes mínimos foi alcançado, sendo realizados alguns ajustes necessários durante a avaliação de seu conteúdo pelos juízes. O instrumento final foi composto por 35 pares, os quais diferem em somente um parâmetro.

ABSTRACT Purpose To design an instrument to check the perception of minimal contrasts by through pairs of signs, which differ in one the following parameters: handshape, hand location, hand movement and hand orientation. Methods An inventory of minimal pairs was made and some pictures were drawn by a visual artist. These pictures were organized into three columns, which could be equal or different from each other in the pair. A video file with an interpreter making two signs at a time was played to the individual taking the test and this was expected to watch the signs and point to the pictures that corresponded to them. Raters analyzed the pairs and decided whether or not they were accurate. They could modify the pairs or ask for particular pairs to be removed; they also checked if the pictures were clear and if they were part of the children's vocabulary. Results The analysis of agreement among raters had a significant result for the criterion rated as 'not a minimal pair'. Thus, 13 items were removed from the instrument because they differed as to more than one parameter, and were considered either analogous or not minimal pairs. Additionally, 16 pairs were modified, and seven pairs which differed in orientation, were added. As a consequence, there was a total of 35 minimal pairs in the final version of the instrument. Conclusion The purpose of designing an instrument for evaluation of the perception of minimal contrasts was achieved. Some adjustments were made during the assessment of the content of the instrument as suggested by raters. The final instrument was composed of 35 pairs which differ from each other in only one parameter.

Subjective visual vertical with the bucket method in Brazilian healthy individuals / Vertical visual subjetiva com o método do balde em indivíduos brasileiros hígidos

ABSTRACT INTRODUCTION: The capacity of a healthy individual to estimate the true vertical in relation to the Earth when a fluorescent line is aligned in a completely dark room is called the subjective visual vertical. OBJECTIVE: To evaluate subjective visual vertical using the bucket method in healthy Brazilian individuals. METHODS: Binocular subjective visual vertical was measured in 100 healthy volunteers, 50 females and 50 males. The volunteers indicated the estimated position in which a fluorescent line inside a bucket reached the vertical position. A total of ten repetitions were performed, five clockwise and five counterclockwise. Data were tabulated and analyzed statistically. RESULTS: It was observed that the highest concentration of absolute values of vertical deviation was present up to 3°, regardless of gender, and the vertical deviation did not increase with age. The analysis of the mean of the absolute values of deviations from the vertical of 90% of the sample showed a maximum value of 2.6°, and at the analysis of 95%, the maximum value was 3.4° deviation from the vertical. CONCLUSION: The bucket method is easy to perform and interpret when assessing the deviation of the subjective visual vertical in relation to the true vertical in healthy Brazilian individuals.

Resumo Introdução: A capacidade que um indivíduo hígido tem em estimar a vertical verdadeira em relação à Terra, quando alinha uma linha fluorescente em uma sala completamente escura é denominada de Vertical Visual Subjetiva (VVS). Objetivo: Avaliar a VVS com o método do balde em indivíduos brasileiros hígidos. Método: A VVS binocular foi medida em 100 voluntários hígidos, 50 do gênero feminino e 50 do masculino. Os voluntários indicaram a posição estimada em que uma linha fluorescente no interior de um balde alcançou a posição vertical. Foram realizadas 10 repetições, cinco no sentido horário e cinco no anti-horário. Os dados foram tabulados e submetidos à análise estatística. Resultados: Observou-se que a maior concentração dos valores absolutos dos desvios da vertical esteve presente até 3º, independente do gênero e o desvio da vertical não aumentou conforme a idade. À análise da média dos valores absolutos dos desvios da vertical de 90% da amostra, foi encontrado o valor máximo de 2,6º e à análise de 95% o valor máximo foi de 3,4 de desvio da vertical. Conclusão: O método do balde é fácil de realizar e de interpretar na avaliação do desvio da vertical visual subjetiva em relação à vertical verdadeira de indivíduos brasileiros hígidos.

A disturbed processing of graviceptive pathways may be involved in the pathophysiology of balance disorders in patients with multiple sclerosis / O processamento incorreto das informações graviceptivas pode estar envolvido na fisiopatologia dos distúrbios do equilíbrio em pacientes com esclerose múltipla

ABSTRACT The purpose of this study was to determine the relationship between perception of verticality and balance disorders in multiple sclerosis patients. We evaluated patients and healthy controls. Patients were divided into two groups according to their risk of fall, with or without risk of fall, measured by a Dynamic Gait Index scale. Graviceptive perception was assessed using the subjective visual vertical test. Patients with risk of fall showed worse perception than those without risk of fall, p < 0.001. Misperception of verticality was correlated with the dynamic gait index scores (p < 0.001), suggesting that the larger the error for verticality judgment, the greater risk for falling. Considering that the perception of verticality is essential for postural control, our results suggested that the disturbed processing of graviceptive pathways may be involved in the pathophysiology of balance disorders in these patients.

RESUMO Nosso objetivo foi determinar a relação entre percepção de verticalidade e alterações do equilíbrio em pacientes com esclerose múltipla (EM). Foram avaliados pacientes e sujeitos saudáveis. Pacientes foram divididos em dois grupos de acordo com o risco de queda, mensurado pelo Índice de marcha dinâmica, formando os grupos com risco e sem risco de quedas. A percepção da verticalidade foi medida através do teste vertical visual subjetiva (VVS). Pacientes com risco de queda apresentaram pior percepção da verticalidade quando comparados aos sem risco, p < 0,001. O desempenho no teste da VVS foi pior em pacientes quando comparado aos controles (p < 0,001). O erro no julgamento da verticalidade foi correlacionado aos índices de risco de queda (p < 0,001), sugerindo que quanto maior o erro no julgamento da verticalidade, maior o risco de queda dos pacientes. Nossos resultados sugerem que alterações das informações em vias graviceptivas podem estar envolvidas nas alterações de equilíbrio dessa população.

Avaliação audiológica infantil: a utilização da audiometria com reforço visual com estímulos de fala / Pediatric hearing evaluation: visual reinforcement audiometry with speech sounds

Algumas teorias propõem que a percepção auditiva para sons complexos, como a fala e sons simples, ocorre de maneira distinta. Teorias sobre a existência de uma rota especial para decodificação da fala, com distinções desde a detecção do espectro acústico, a despolarização não linear das fibras do nervo auditivo, até a localização de neurônios especializados para interpretar sons de fala a nível cortical. Seria possível esta habilidade específica de percepção de fala um fator que modificaria as respostas de crianças entre 6 a 24 meses durante uma avaliação comportamental? Para avaliação audiológica nesta faixa etária, a Audiometria com Reforço Visual (VRA) é o exame indicado para obter níveis mínimos de audição (NMA). Diversos estudos apresentam as indicações da técnica do VRA para obter respostas confiáveis do sistema auditivo. Diante destas perguntas, determinou-se realizar um estudo comparativo do VRA com dois estímulos: warble nas frequências de 0.5, 1, 2 e 4kHz, e estímulos de fala, os seis sons de Ling /a/, /i/, /u/, /s/, /?/, /m/. Os dois exames foram aplicados em crianças com e sem deficiência auditiva, com os objetivos de determinar os NMA, o tempo de teste, número de sessões e os comportamentos observados durante a avaliação. Além da investigação quantitativa, foi elaborado um guia de orientações para realização do VRA. Foram avaliadas 123 crianças, as quais 57 foram inclusas na pesquisa, os principais motivos de exclusão foram: timpanogramas alterados, deficiências múltiplas, atraso motor e desordem do espectro da neuropatia auditiva. Participaram do grupo controle (GC) 33 crianças sem deficiência auditiva, idade média de 12 meses, e 24 com deficiência auditiva do grupo experimental (GE), idade média de 18 meses. No total foram obtidos 718 NMA considerando as 57 crianças e os 10 estímulos avaliados. Para o GC a média do VRA-warble foi de 17,05 dBNA e para o VRA-Ling de 13,60 dBNA; no GE as médias foram respectivamente, 95,51 dBNA e 85,88 dBNA, ou seja, estatisticamente os valores obtidos com os sons de Ling foram menores do que os obtidos com o estímulo warble. Os tempos médios para obtenção de pelo menos um NMA ou todos os NMA com o Ling e warble, não se diferiram na comparação intra grupos, assim como o número de sessões realizadas. No entanto, observou-se na comparação entre grupos, que o número de sessões, o número de NMA obtidos e o tempo de teste na realização do VRA-warble, foram maiores no GE. Outros comportamentos foram observados durante o decorrer do VRA: atenção, reflexo de orientação, imitação do estímulo auditivo, apontar para o fone, olhar para avaliadora/mãe. Considerando os resultados obtidos: o protocolo de teste utilizado mostrou-se eficaz para obtenção dos NMA nos dois grupos estudados; os sons de Ling podem ser utilizados na avaliação audiológica infantil de forma a complementar os achados com os estímulos de frequência específica. Porém, uma vez que os sons de Ling possuem uma ampla faixa de frequência, outros estudos que correlacionem os NMA para os sons de Ling nas diferentes configurações audiométricas são necessários.

Some theories postulate the auditory perception to complex sounds and simple sounds, occur differently. Theories about the existence of a special route for decoding speech, with distinctions from the detection of the acoustic spectrum, nonlinear depolarization of the auditory nerve fibers to the location of specialized neurons to interpret speech sounds at the cortical level. Is it possible this specific skill of speech perception a factor that would change the responses of children aged 6 to 24 months during a behavioral assessment? For audiological evaluation in this age group, with Visual Reinforcement Audiometry (VRA) is the test to obtain minimum response levels (MRL) or thresholds. Faced with these questions, determined to carry out a comparative study of the VRA with two stimuli: warble tones in the frequencies of 0.5, 1, 2 and 4 kHz, and speech stimuli, the six Ling sounds /a/, /i/, /u/, /s/, /?/, /m/. Both tests were applied in children with and without hearing impairment with the objective of determining the NMA, test time, number of sessions and the behavior observed during the assessment. In addition to quantitative research, we designed a guide guidelines for conducting the VRA. 123 children were evaluated, of which 57 were included in the survey, the main reasons for exclusion were changed tympanograms, multiple disabilities, delayed motor and auditory neuropathy spectrum disorder. Participated in the control group (CG) 33 children without hearing impairment, mean age 12 months, and 24 with hearing loss in the experimental group (GE), average age of 18 months. In total 718 were obtained NMA considering the 57 children and 10 evaluated stimuli. For the GC average of VRA-warble was 17.05 dBHL and for VRA-Ling of 13.60 dB HL; GE in the averages were respectively 95.51 and 85.88 dBHL dBNA, ie, statistically the values obtained with the sounds of Ling were lower than those obtained with the warble stimulus. The average time to achieve at least one or all of the NMA NMA with Ling and warble, did not differ compared intra groups, as well as the number of sessions. However, it was noted in comparison between groups, the number of sessions, the number of NMA obtained and the and the test time in achieving VRA-warble were higher in the EG. Other behaviors were observed during the course of the VRA: attention, orientation reflex, imitation of auditory stimuli, point to the phone, look appraiser / mother. Considering the results obtained: the test protocol used was effective for obtaining the NMA in both groups; Ling sounds can be used in the audiological evaluation of children to complement the findings with specific frequency stimuli. However, since Ling sounds have a wide range of frequencies, other studies correlating to NMA Ling sounds in different audiometric configurations are needed.

Mortalidad infantil por malformaciones congénitas en Chile: análisis temporal y espacial, 1997-2011 / Infant mortality from congenital malformations in Chile: temporal and spatial analysis, 1997-2011

OBJETIVO:Analizar la distribución espacial y temporal (1997-2011) de la mortalidad infantil por malformaciones congénitas (MC) en Chile. MÉTODOS: Los datos de nacimientos y muertes en menores de 1 año de edad codificados con la CIE-10 se obtuvieron del Instituto Nacional de Estadísticas. Para las regiones administrativas y las naturales (Norte Grande, Norte Chico, Central, Austral y Sur), sistemas (nervioso, cardiovascular, digestivo, genitourinario, musculo esquelético, anomalías cromosómicas) y 28 malformaciones específicas, se estimaron el porcentaje de muertes por MC (PM-MC) y la tasa de mortalidad infantil por MC (TMI-MC) en 3 períodos (1997-2001, 2002-2009, 2007-2011). La tendencia secular y la variación del riesgo de muerte se estimaron con un modelo de regresión de Poisson. RESULTADOS: Para todo Chile, la tendencia secular de la TMI-MC y el PM-MC fueron negativa y positiva, respectivamente (P < 0,01). La TMI-MC y el PM-MC exhibieron una heterogeneidad espacial discreta en las regiones administrativas y naturales. La región natural que más se acercó al patrón nacional fue la Central. La tendencia secular de la TMI-MC de los sistemas nervioso y cardíaco y de algunas MC específicas (anencefalia, espina bífida, y comunicaciones interauricular e interventricular) fue negativa. El patrón de mortalidad infantil por MC para todo Chile se caracteriza por presentar en el período 1997-2011 un descenso de la TMI-MC y un aumento del PM-MC. CONCLUSIONES: Los resultados indican que Chile se encuentra en un estadio avanzado de la transición epidemiológica de las causas de mortalidad infantil. Sin embargo, se observan disparidades interregionales de estos indicadores, más notorias en el sur del país.

OBJECTIVE: To analyze the spatial and temporal distribution (1997-2011) of infant mortality resulting from congenital malformations (CM) in Chile. METHODS: Data on births and deaths among infants aged less than one year using ICD-10 coding were obtained from the National Statistics Institute. The percentage of deaths from CM (PD-CM) and the infant mortality rate from CM (IMR-CM) during three different periods (1997-2001, 2002-2009, 2007-2011) were estimated for Chile's administrative and natural regions (Norte Grande, Norte Chico, Central, Austral, and Sur), broken down by systems (nervous, cardiovascular, digestive, genitourinary, musculoskeletal, and chromosomal abnormalities) and by 28 specific malformations. The secular trend and the variation in the risk of death were estimated using a Poisson regression model. RESULTS: For the whole of Chile, the secular trend for the IMR-CM was negative, and the secular trend for the PD-CM was positive (P < 0,01). The IMR-CM and the PD-CM both showed mild spatial heterogeneity in all administrative and natural regions. The Central region was the natural region that came closest to showing the pattern observed nationwide. The IMR-CM involving the nervous and cardiovascular systems and specific types of CM (anencephaly, spina bifida, and atrial and ventricular septal defects) showed a negative secular trend. For Chile as a whole, the pattern of infant mortality from CM is marked by a drop in the IMR-CM and by an increase in the PD-CM over the period from 1997 to 2011. CONCLUSION: The findings suggest that Chile is in the latter stages of the epidemiological transition with respect to the causes of infant mortality. However, these indicators show disparities between regions, more pronounced in the south of the country.

The competition with a concurrent cognitive task affects posturographic measures in patients with Parkinson disease / A competição com uma tarefa cognitiva afeta medidas posturográficas de pacientes com doença de Parkinson

ABSTRACTObjectives To estimate the impact of a sensory-motor- cognitive task on postural balance, in Parkinson disease patients (Hoehn and Yahr 2-3) and to investigate possible relationships between posturography and functional balance clinical scales.Method Parkinson disease patients (n = 40) and healthy controls (n = 27) were evaluated with fluency tests, Berg Balance scale, Mini Best test and static posturography on the conditions eyes open, eyes closed and dual-task (simultaneous balance and fluency tasks).Results Posturographic data showed that Parkinson disease patients performed worse than controls in all evaluations. In general, balance on dual-task was significantly poorer than balance with eyes closed. Posturographic data were weakly correlated to clinical balance scales.Conclusion In clinical practice, Parkinson disease patients are commonly assessed with eyes closed, to sensitize balance. Our study showed that adding a cognitive task is even more effective. Static posturographic data should be carefully overgeneralized to infer functional balance impairments.

RESUMOObjetivos Estimar o impacto de uma tarefa sensório-cognitivo-motora no equilíbrio, em pacientes com doença de Parkinson e investigar possíveis relações entre dados posturográficos e escalas de equilíbrio funcional.Método Pacientes (n = 40) e controles (n = 27) foram avaliados com testes de fluência verbal, escala de equilíbrio de Berg (BBS), Mini Best Test (MBT) e posturografia estática nas condições olhos abertos, olhos fechados e tarefa-dupla (equilíbrio e fluência verbal, simultaneamente).Resultados Dados posturográficos mostraram que pacientes apresentaram pior desempenho que controles em todas as avaliações. O equilíbrio na dupla-tarefa foi pior que na privação visual. Dados posturográficos apresentaram correlações fracas com a a BBS e MBT.Conclusão Pacientes com Parkinson são comumente avaliados com olhos fechados para sensibilizar o equilíbrio. Nosso estudo mostra que a adição de uma tarefa cognitiva é mais efetiva. Dados da posturografia estática devem ser generalizados com cuidado nas interferências sobre equilíbrio.

Naming ability in patients with mild to moderate Alzheimer’s disease: what changes occur with the evolution of the disease?

OBJECTIVES: Naming deficit is a linguistic symptom that appears in the initial phase of Alzheimer’s disease, but the types of naming errors and the ways in which this deficit changes over the course of the disease are unclear. We analyzed the performance of patients with Alzheimer’s disease on naming tasks during the mild and moderate phases and verified how this linguistic skill deteriorates over the course of the disease. METHODS: A reduced version of the Boston Naming Test was administered to 30 patients with mild Alzheimer’s disease, 30 patients with moderate Alzheimer’s disease and 30 healthy controls. Errors were classified as verbal semantic paraphasia, verbal phonemic paraphasia, no response (pure anomia), circumlocution, unrelated verbal paraphasia, visual errors or intrusion errors. RESULTS: The patients with moderate Alzheimer’s disease had significantly fewer correct answers than did both the control group and the group with mild Alzheimer’s disease. With regard to the pattern of errors, verbal semantic paraphasia errors were the most frequent errors in all three groups. Additionally, as the disease severity increased, there was an increase in the number of no-response errors (pure anomia). The group with moderate Alzheimer’s disease demonstrated a greater incidence of visual errors and unrelated verbal paraphasias compared with the other two groups and presented a more variable pattern of errors. CONCLUSIONS: Performance on nominative tasks worsened as the disease progressed in terms of both the quantity and the type of errors encountered. This result reflects impairment at different levels of linguistic processing. .

The eye-tracking of social stimuli in patients with Rett syndrome and autism spectrum disorders: a pilot study / Rastreamento do olhar para estímulos sociais em pacientes com síndrome de Rett e transtornos do espectro do autismo: estudo piloto

Objective To compare visual fixation at social stimuli in Rett syndrome (RT) and autism spectrum disorders (ASD) patients. Method Visual fixation at social stimuli was analyzed in 14 RS female patients (age range 4-30 years), 11 ASD male patients (age range 4-20 years), and 17 children with typical development (TD). Patients were exposed to three different pictures (two of human faces and one with social and non-social stimuli) presented for 8 seconds each on the screen of a computer attached to an eye-tracker equipment. Results Percentage of visual fixation at social stimuli was significantly higher in the RS group compared to ASD and even to TD groups. Conclusion Visual fixation at social stimuli seems to be one more endophenotype making RS to be very different from ASD. .

Objetivo Comparar a fixação visual em estímulos sociais em pacientes com síndrome de Rett (SR) e com transtornos do espectro do autismo (TEA). Método Fixação visual em estímulos sociais foi analisada em 14 pacientes do sexo feminino com SR (idades entre 4 e 30 anos), 11 pacientes do sexo masculino com TEA (idades entre 4 e 20 anos), e 17 crianças do sexo feminino com desenvolvimento típico (DT). Os participantes foram expostos a três figuras diferentes (duas figuras de faces humanas e uma figura contendo estímulo social e não social) apresentadas por 8 segundos cada uma no monitor de um computador acoplado a um equipamento de rastreamento de olhar. Resultados A porcentagem de fixação visual em estímulos sociais foi significativamente maior no grupo SR do que no grupo TEA e mesmo no grupo DT. Conclusão A fixação visual em estímulos sociais parece ser mais um dos endofenótipos que esclarecem as diferenças entre SR e TEA. .

Vulnerabilidade de famílias de idosos assistidos pela Estratégia Saúde da Família / Vulnerabilidad de las familias de adultos mayores asistidas por la Estrategia Salud de la Familia / Vulnerability of families of elderly citizens cared for by the Family Health Strategy

RESUMO Objetivo: estudo descritivo, exploratório, de corte transversal, cujo objetivo foi identificar a vulnerabilidade de famílias de idosos assistidos pela Estratégia Saúde da Família (ESF). Método: foi desenvolvido por meio de entrevistas domiciliárias realizadas com uma amostra de 500 famílias de idosos assistidas por 32 equipes da ESF da cidade de Dourados, MS. O Índice de Desenvolvimento da Família (IDF) foi adaptado para classificá-las em função da situação de vulnerabilidade. Resultados: os resultados revelaram a presença de famílias multigeracionais, com baixa escolaridade entre os indivíduos com idade superior a 20 anos e alta taxa de analfabetismo entre os idosos. Identificaram-se 403 famílias em situação de vulnerabilidade aceitável, 95 em vulnerabilidade grave e duas famílias em situação de vulnerabilidade muito grave. As dimensões mais críticas do IDF foram os acessos ao conhecimento e ao trabalho. Conclusão: conclui-se que há necessidade de mais investimentos no cuidado a esses idosos e suas famílias na Atenção Básica. .

RESUMEN Objetivo: estudio descriptivo, exploratorio, transversal, con el objetivo de identificar la vulnerabilidad de familias adultos mayores asistidas por la Estrategia Salud de la Familia (ESF). Método: fue desarrollado mediante entrevistas a una muestra de 500 familias de adultos mayores bajo la responsabilidad de 32 equipos de ESF en la ciudad de Dourados, MS, Brasil. El Índice de Desarrollo de la Familia (IDF) fue adaptado para clasificar las familias de acuerdo a la situación de vulnerabilidad. Resultados: los resultados revelaron la presencia de familias multigeneracionales con bajo nivel de educación entre las personas mayores de 20 años y las altas tasas de analfabetismo entre los adultos mayores. Se identificaron 403 familias en situación de vulnerabilidad aceptable, 95 con vulnerabilidad grave y dos familias en situación de vulnerabilidad muy grave. Las dimensiones más críticas en el IDF fueron el acceso al conocimiento y al trabajo. Conclusión: se concluye que existe la necesidad de una mayor inversión, con un enfoque en la atención primaria, con el fin de atender a las personas mayores y sus familias. .

ABSTRACT Objective: the present descriptive, exploratory, cross-sectional study aimed to identify the vulnerability of families of elderly citizens cared for by the Family Health Strategy (FHS). Method: the research employed home interviews and was developed with a sample of 500 families of aged people cared for by 32 FHS teams in the city of Dourados, MS, Brazil. The Family Development Index (FDI) was adapted in order to classify the families according to their degree of vulnerability. Results: the results revealed the presence of multigenerational families with low educational levels among individuals over the age of 20 and high illiteracy rates among elderly citizens. There were 403 families whose vulnerability was acceptable, 95 in severe vulnerability, and two families in a condition of very severe vulnerability. The most critical dimensions of the FDI were the access to knowledge and to work. Conclusion: the study identifi ed that there is still a need for further investments that can assist these aged people and their families in the Primary Health Care. .

Interaction between affordance and handedness recognition: a chronometric study

The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation.