Leitura de palavras e pseudopalavras em adultos jovens: um estudo de rastreamento ocular / Word and pseudoword reading in young adults: an eye-tracking study

RESUMO Objetivo Avaliar e caracterizar o comportamento oculomotor durante a leitura de pseudopalavras e palavras do português brasileiro caracterizadas quanto à frequência, extensão e regularidade e verificar sua relação com o desempenho em testes neuropsicológicos. Método 21 alunos universitários com média de idade de 20,9 anos realizaram a Tarefa de Leitura de Palavras e Pseudopalavras (TLPP) da Bateria Anele, além de testes de fluência verbal e de memória operacional fonológica. Foram estudados os padrões de duração da primeira fixação do olhar no estímulo, duração total das fixações no estímulo e a taxa de refixações (taxa de retornos ao estímulo). Resultados A duração da primeira fixação e a duração total das fixações foram significativamente menores para palavras em relação às pseudopalavras, bem como a duração total das fixações foi menor para palavras frequentes e curtas. Também foram encontradas interações significativas entre o desempenho na fluência verbal e a duração da primeira fixação. Conclusão Nossos resultados demonstram a aplicabilidade do rastreador ocular para avaliar a leitura no nível da palavra no Português Brasileiro. O rastreador ocular pode ser um instrumento adicional na investigação de transtornos de leitura do desenvolvimento e adquiridos, podendo auxiliar na detecção de dificuldades de leitura a partir da análise de diferenças do comportamento oculomotor entre leitores fluentes e não-fluentes.

ABSTRACT Purpose To evaluate and characterize the oculomotor behavior during the reading of words and pseudowords in Brazilian Portuguese organized by frequency, length and regularity and verify its association with performance on neuropsychological tests. Methods 21 university students, with a mean age of 20.9 years, were submitted to a word and pseudoword reading task (TLPP) from the Anele Battery, in addition to verbal fluency and phonological working memory tests. The patterns of first fixation duration, gaze duration and rate of refixation were studied. Results The first fixation duration and the gaze duration were significantly lower for words if compared to pseudowords and the gaze duration was also lower for high-frequency and short words. Significant interactions were also found between verbal fluency performance and the first fixation duration. Conclusion Our results demonstrate the applicability of eye tracking to study reading patterns at the word-level in Brazilian Portuguese. The eye tracker can be an additional tool in the investigation of acquired and developmental reading disorders and can assist in the detection of reading difficulties based on comparisons of the oculomotor behavior between fluent and non-fluent readers.

Phase portrait analysis of eye movement waveforms in congenital nystagmus eyes / 中华实验眼科杂志

Background The characteristics of eye movement waveforms in congenital nystagmus eyes is so complicated that the time-series waveform can hardly demonstrate the oscillational kinetic property of the eye movement of nystagmus,which is not convenient for the clinical diagnosis and evaluation.The eye movement system is a nonlinear feedback control system,and phase portrait analysis is a useful method in describing the characteristics of movement in a nonlinear system.Objective This study was to establish the phase portrait analysis method of the eye movement waveforms in congenital nystagmus eyes and provide a new technique for the clinical diagnosis and evaluation of congenital nystagmus.Methods A prospective series-case observational study was performed.This study complied with the Declaration of Helsinki and was approved by Ethic Commission of Tianjin Eye Hospital.Written informed consent was obtained from each patient before examination.Twenty-five patients with congenital nystagmus were enrolled and received examination of video-oculography (VOG) in Tianjin Eye Hospital from April 2012 to February 2013,including 12 patients with congenital motor nystagmus (CMN) and 13 patients with latent nystagmus (LN).The VOG data were format-converted and processed by a Matlab routine.VOG-based phase portraits of eye movement cycles were drawn and related parameters were measured from the phase portraits for further analysis and comparison.Main measurement indexes were cycle position shift (CPS),slow phase peak velocity (SPV),standardized slow-phase peak (SSPV),fast phase peak velocity (FPV) and standardized fast-phase peak velocity (SFPV).Two principal types of waveforms,increasing-velocity type and decreasing-velocity type were compared.Results The phase portraits of the waveforms of congenital nystagmus were cycles of reciprocating trajectories.The slow phases were in dense ribbon region,and the fast phases were in sparse annular region,and all the trajectories travelled in clockwise.The CPS,SPV and FPV of increasing-velocity type were (4.646 ± 1.565),(223.821 ± 114.049),(767.481 ±263.560) ° per second,respectively.The CPS,SPV and FPV of decreasing-velocity type were (9.373 ±4.189),(357.531 ± 154.300) and (1 148.706 ±541.362) ° per second,respectively.The SPVs and FPVs of both increasing-velocity type and decreasing-velocity type showed strong correlation with CPS,respectively (the increasing-velocity type:rSPV-CPS =0.685,P=0.000;rFPV-CPS =0.680,P=0.000;the decreasing-velocity type rSPV-CPS =0.783,P =0.000;rFPV-CPS =0.803,P =0.000).FPVs were significantly larger than SPVs in both types of waveforms (t =6.558,P =0.000;t =5.068,P =0.000).The SSPV of increasing-velocity type was (48.062 ± 15.365) ° per second,which was slightly larger than (41.099± 17.027) ° per second of decreasing-velocity type,with no significant difference between them (t=1.070,P=0.296).The SFPV of increasing-velocity type was (171.186±47.825)° per second,which was larger than (125.317-±38.266)° per second of decreasing-velocity type,showing a significant difference between them (t =2.658,P =0.014).Conclusions Phase portraits can visualize the cyclically dynamic features of congenital nystagmus in a direct way.It facilitates the measurement of eye movement amplitude,speed and other parameters.The phase portrait analysis method provides a novel useful tool in the clinical diagnosis and treatment efficacy evaluation of congenital nystagmus.

Estrabismos: da teoria à prática, dos conceitos às suas operacionalizações / Strabismus: from theory to practice, from concepts to its operational attainment

Analisam-se particularidades inerentes ao estudo dos estrabismos, tais como as dificuldades para suas definições e os diferentes modos com os quais eles podem ser concebidos, a relatividade com que as posições binoculares possam ser interpretadas e os elementos referenciais necessários para a circunscrição dessas questões. A partir daí, discute-se o conceito de posição primária do olhar e as condições de sua operacionalização, concluindo-se pela impossibilidade de concretização desse ponto "zero", a partir do qual seriam feitas as medidas dos estrabismos e as quantificações de movimentos oculares. A seguir, passa-se ao exame da construção dos múltiplos sistemas referenciais aplicáveis à quantificação dos estrabismos, de cuja falta de consenso sobre qual deles usar decorrem implicações práticas elementares, como a falta de padronização do modo de superposição ortogonal de prismas, para a medida de desvios combinados, horizontal e vertical. Comenta-se a assimetria funcional das rotações oculares e suas exceções. Também se analisa a precisão com que se pode fazer a medida de um estrabismo, levando à conclusão sobre a impropriedade de uso de medidas fracionárias com as unidades angulares mais comumente usadas. Finalmente, são comentados alguns problemas técnicos dessas avaliações, tais como o das dificuldades operacionais relacionadas à dioptria-prismática, os subordinados ao uso de prismas e os da ocorrência de efeitos prismáticos pelo uso de lentes convencionais.

Some particular points concerning the study of strabismus are analyzed, specially, the difficulties for definitions and the different ways it can be conceived, besides the relativity of binocular positions interpretation, and the necessary referential elements for circumscribing such questions. Then, the concept of primary position of gaze is discussed as well as the conditions for its operational attainment, leading to the conclusion that it is materially impossible to achieve this "zero" point, from which all other measurements of strabismus or ocular movements should be done. In sequence, the construction of multiple referential systems applying the quantification of strabismus are examined. The lack of consensual agreement about which should be used as the standard system causes elementary practical implications, as the lack of agreement about how to superimpose orthogonal prisms for the measurement of associated horizontal and vertical deviations. The functional asymmetry of ocular rotations and its exceptions are commented. The accuracy that the measurements of strabismus can be performed is analyzed, leading to the conclusion that fractional figures using the commonest angular unities are improper. At last, some technical problems related to such evaluations are also commented, as operational difficulties related to prism-diopter unity, concerning the use of prisms, and prismatic effects due to the use of conventional optical glasses.

Concepts of color, shape, size and position in ten children with Rett syndrome / Conceitos de cor, forma, tamanho e posição em dez crianças com síndrome de Rett

Individuals with Rett syndrome (RS) present severe motor, language and cognitive deficits, as well as spontaneous hand movement loss. On the other hand, there are strong evidence that these individuals use the eyes with intentional purpose. Ten girls aged 4y8m to 12y10m with RS were assessed with a computer system for visual tracking regarding their ability of indicating with eyes the recognition of concepts of color (red, yellow and blue), shape (circle, square and triangle), size (big and small) and spatial position (over and under) to which they were first exposed to. Results from comparing the time of eyes fixation on required and not required concepts did not differ significantly. Children did not show with eyes the recognition of the required concepts when assessed with eye tracking system.

Pessoas com síndrome de Rett (SR) apresentam severos prejuízos psicomotores, verbais, cognitivos e perda das habilidades manuais proposicionais que impedem o conhecimento de suas reais aquisições intelectuais. Entretanto, estudos relatam que essas pessoas utilizam o olhar com finalidade intencional. O objetivo deste estudo foi avaliar se crianças com SR, após terem sido expostas aos conceitos de cor (vermelho, amarelo e azul), forma (círculo, quadrado e triângulo), tamanho (grande e pequeno) e posição espacial (em cima e em baixo), manifestam o reconhecimento desses conceitos com o olhar, avaliado com equipamento computadorizado de rastreamento ocular. Foram avaliadas dez crianças com diagnóstico de SR, com idades entre 4 anos e 8 meses e 12 anos e 10 meses. Os resultados não indicaram diferenças significativas no tempo de fixação do olhar das crianças quando comparados os conceitos solicitados e os não solicitados. Concluiu-se que, com o método utilizado, as crianças não reconheceram os conceitos avaliados.