Auditory temporal resolution and backward masking in musicians with absolute pitch.

Among the many questions regarding the ability to effortlessly name musical notes without a reference, also known as absolute pitch, the neural processes by which this phenomenon operates are still a matter of debate. Although a perceptual subprocess is currently accepted by the literature, the participation of some aspects of auditory processing still needs to be determined. We conducted two experiments to investigate the relationship between absolute pitch and two aspects of auditory temporal processing, namely temporal resolution and backward masking. In the first experiment, musicians were organized into two groups according to the presence of absolute pitch, as determined by a pitch identification test, and compared regarding their performance in the Gaps-in-Noise test, a gap detection task for assessing temporal resolution. Despite the lack of statistically significant difference between the groups, the Gaps-in-Noise test measures were significant predictors of the measures for pitch naming precision, even after controlling for possible confounding variables. In the second experiment, another two groups of musicians with and without absolute pitch were submitted to the backward masking test, with no difference between the groups and no correlation between backward masking and absolute pitch measures. The results from both experiments suggest that only part of temporal processing is involved in absolute pitch, indicating that not all aspects of auditory perception are related to the perceptual subprocess. Possible explanations for these findings include the notable overlap of brain areas involved in both temporal resolution and absolute pitch, which is not present in the case of backward masking, and the relevance of temporal resolution to analyze the temporal fine structure of sound in pitch perception.

Evidence of Validity and Normative Values of a New Auditory Backward Masking Test.

There are still no valid, clinically feasible instruments to assess backward masking (BM), an auditory temporal processing (ATP) phenomenon. The aim of this study was to develop, standardize and present evidence of validity for a behavioral test for BM assessment. Young adults were submitted to a BM test (BMT), where they were asked to identify a 1000 Hz pure tone followed by a narrowband noise with interstimulus intervals of 0 to 400 ms and signal-to-noise ratio (SNR) between -20 and -30 dB. The correct response rate and target sound detection threshold were calculated, and the results compared with those of young adults with abnormal ATP tests and older adults. Diagnostic accuracy analyses were carried out. Young adults with normal ATP obtained an average correct response rate of 89 and 87% for SNR -20 and -30 dB, respectively, with average thresholds between 10 and 15 ms and no difference between the left and right ears. Results were more consistent at SNR -20 dB, and the best diagnostic accuracy was obtained for SNR -20 dB, with good specificity, but low sensitivity. Normative values were obtained for the BMT, which proved to be clinically feasible, with preliminary evidence of validity.

Impulsive and Omission Errors: Potential Temporal Processing Endophenotypes in ADHD.

Temporal processing (TP) is associated with functions such as perception, verbal skills, temporal perspective, and future planning, and is intercorrelated with working memory, attention, and inhibitory control, which are highly impaired in individuals with attention deficit hyperactivity disorder (ADHD). Here we evaluate TP measures as potential endophenotypes in Caribbean families ascertained from probands affected by ADHD. A total of 232 individuals were recruited and clinically evaluated using an extensive battery of neuropsychological tasks and reaction time (RT)-based task paradigms. Further, the heritability (genetic variance underpinning phenotype) was estimated as a measure of the genetics apportionment. A predictive framework for ADHD diagnosis was derived using these tasks. We found that individuals with ADHD differed from controls in neuropsychological tasks assessing mental control, visual-verbal memory, verbal fluency, verbal, and semantic fluency. In addition, TP measures such as RT, errors, and variability were also affected in individuals with ADHD. Moreover, we determined that only omission and commission errors had significant heritability. In conclusion, we have disentangled omission and commission errors as possible TP endophenotypes in ADHD, which can be suitable to assess the neurobiological and genetic basis of ADHD. A predictive model using these endophenotypes led to remarkable sensitivity, specificity, precision and classification rate for ADHD diagnosis, and may be a useful tool for patients' diagnosis, follow-up, and longitudinal assessment in the clinical setting.

Facilitadores en el procesamiento cognitivo de la información rítmica. Revisión de la literatura sobre los conceptos de pulso, tempo, metro y acento / Facilitating factors in the cognitive processing of rhythmic information. A review of the literature on the concepts of pulse, tempo, meter and accent

Resumen Los modelos de percepción del ritmo han estudiado una importante variedad de características generales de las estructuras temporales y elementos específicos del ritmo musical, y presentan un grado de heterogeneidad en los objetos de estudio. Sin embargo, la mayoría de las investigaciones convergen en el análisis de los procesos relacionados con la detección, por parte del oyente, de un pulso temporal subyacente. Estos procesos, junto con otros como la agrupación temporal, se han denominado "aspectos básicos" o "primitivos", ya que parecen fundamentales para la percepción de secuencias rítmicas simples. En el presente trabajo se hace una revisión de la literatura en la que se describen, sintetizan y relacionan los hallazgos de las investigaciones vinculadas con el procesamiento cognitivo de los aspectos rítmicos básicos (pulso, tempo, metro y acento) con el objeto de especificar ciertas características temporales que facilitan la comprensión psicológica del ritmo. La información presentada se ha obtenido de revistas científicas indexadas y de textos fundamentales en el estudio del procesamiento temporal y rítmico a nivel cognitivo. En relación con el pulso, parece existir consenso en que los seres humanos tienden a la isocronía y a la regularidad, y el espectro de tempo óptimo es aquel que oscila entre 60 y 120 pulsos por minuto. Los niños pequeños tendrían un tempo preferido más rápido. El metro conforma un marco que permite la previsibilidad y organización de los eventos rítmicos futuros, y se evidencia una predisposición de las personas hacia los metros binarios por sobre los ternarios. Los hallazgos presentados en este artículo deben ser considerados en el futuro para promover la comprensión psicológica del ritmo en diversos contextos individuales y/o grupales, especialmente en educación musical.

Abstract Rhythm perception models have studied an important variety of general characteristics of temporal structures and specific elements of musical rhythm, presenting a degree of heterogeneity in study objects. However, most of the research converges in the study of processes related to the listener's detection of an underlying temporal pulse. This, along with other processes such as temporal grouping, have been referred to as basic or primitive aspects, since they seem fundamental to the perception of simple rhythmic sequences. In the present work, a review of the literature in which research findings related to the cognitive processing of basic rhythmic aspects are described, synthesized and related: pulse, tempo, meter and accent. This review aims to specify certain temporal characteristics that facilitate the psychological understanding of rhythm. The information presented has been obtained from scientific journals indexed in Wos and Scopus; from Research Handbook on Education-Musical Cognition and; from fundamental texts in the study of temporal and rhythmic processing at the cognitive level. Among the basic elements that make up the musical rhythm, perhaps the most intrinsic and natural is the pulse. There seems to be consensus that humans, either by processes of enculturation or by biological aspects mainly related to the nervous system, tend to isochronyand regularity. Pulse velocity, called in musical language as tempo, is an important factor to consider when facilitating the processing of rhythmic structures. This is how, the preferred pulse or optimal tempo spectrum for all, regardless of musical formation, age, or personal characteristics; ranges from 60 to 120 pulses or beats per minute (bpm). In addition, recent research findings show that young children have a preferred tempo of 140-150 bpm (400 ms approximately), which is a faster rate for adults: 100 bpm (600 ms approximately). This preference for fast tempi, decreases with age, showing improved responses to a greater diversity of slow and fast tempi thanks to the increase in cognitive and motor development. The meter is another factor that strongly influences the psychological understanding of the rhythm. The meter has been defined as a sequence of regular pulse cycles that include "strong" and "soft" impacts organized at hierarchical levels. It has been proposed that the meter forms a framework for rhythmic expectation that anticipates the central or accented pulse, allowing the predictability and organization of future rhythmic events involved in a fragment or piece of music. This process appears to be automatic and is explained by the brain constantly setting predictions by comparing the previous information accumulated with the sensory stimulus it perceives from the outside. In the context of Western music, a predisposition by listeners towards binary meters (sequences of accented pulses every two, four, etc.) has been proposed rather than to the ternaries (pulse sequences accentuated every three, six, etc.). This has led to hypothesize regarding the existence of improved processing for hierarchical binary relationships in contrast to the more complex or ternary. Finally, the findings presented in this article should be considered in the future to promote psychological understanding of the rhythm in various individual and/or group contexts, especially in formative - musical areas.

Impact of Lipid-Inflammatory-Oxidative Metabolism on Auditory Skills after Hearing Aid Fitting in the Elderly.

This study aimed to assess whether lipid-inflammatory-oxidative metabolism influences auditory processing skills, and whether they function in changing auditory performance after hearing aid fitting in the elderly. Twelve subjects with bilateral hearing loss were submitted to blood tests (to check their lipid-inflammatory-oxidative metabolism) and auditory processing skill tests. After 3 months of using the hearing aids, their auditory skills were re-evaluated and the data were correlated statistically. Oxidative stress levels mainly showed some impact on auditory temporal processing; such a relation and others should best be examined in further studies with larger populations.

Effect of conductive hearing loss on central auditory function / Efeito da perda auditiva condutiva na função auditiva central

Abstract Introduction: It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. Objective: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. Methods: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. Results: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p = 0.004; left: p < 0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p < 0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p > 0.05). Conclusion: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.

Resumo Introdução: Já foi demonstrado que a perda auditiva condutiva (PAC), em longo prazo, pode influenciar na detecção precisa das características temporais dos sinais acústicos ou do processamento auditivo temporal (PAT). Pode-se argumentar que o PAT pode ser o componente subjacente de muitos recursos do processamento auditivo central, como a compreensão da fala ou localização do som. Pouco se sabe sobre as consequências da PAC nos aspectos temporais do processamento auditivo central. Objetivo: Este estudo foi projetado para avaliar a capacidade de processamento auditivo temporal em indivíduos com PAC crônica. Método: Durante este estudo transversal analítico, 52 pacientes com PAC crônica leve a moderada e 52 indivíduos com audição normal (controle), entre 18 e 45 anos, foram recrutados. Para avaliar o processamento auditivo temporal, foi usado o teste de resolução temporal Gaps-in-Noise (GIN). Os resultados obtidos para cada orelha foram analisados com base no limiar de percepção da quebra de continuidade (gap) e na porcentagem de respostas corretas. Resultados: A média dos limiares no GIN foi significativamente menor para o grupo controle do que para o grupo PAC em ambas as orelhas (direita: p = 0,004; esquerda: p < 0,001). Os indivíduos com PAC apresentaram respostas corretas significativamente mais baixas do que os indivíduos com audição normal em ambas as orelhas (p < 0,001). Não houve correlação entre o desempenho no GIN e o grau de perda auditiva em ambos os grupos (p > 0,05). Conclusão: Os resultados sugerem uma redução da capacidade de processamento auditivo temporal em adultos com PAC comparados com indivíduos que apresentam audição normal. Portanto, o desenvolvimento de um protocolo clínico para avaliar o processamento auditivo temporal nessa população é recomendado.

Effect of conductive hearing loss on central auditory function.

INTRODUCTION: It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. OBJECTIVE: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. METHODS: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. RESULTS: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p=0.004; left: p<0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p<0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p>0.05). CONCLUSION: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.

Habituation of Auditory Steady State Responses Evoked by Amplitude-Modulated Acoustic Signals in Rats.

Generation of the auditory steady state responses (ASSR) is commonly explained by the linear combination of random background noise activity and the stationary response. Based on this model, the decrease of amplitude that occurs over the sequential averaging of epochs of the raw data has been exclusively linked to the cancelation of noise. Nevertheless, this behavior might also reflect the non-stationary response of the ASSR generators. We tested this hypothesis by characterizing the ASSR time course in rats with different auditory maturational stages. ASSR were evoked by 8-kHz tones of different supra-threshold intensities, modulated in amplitude at 115 Hz. Results show that the ASSR amplitude habituated to the sustained stimulation and that dishabituation occurred when deviant stimuli were presented. ASSR habituation increased as animals became adults, suggesting that the ability to filter acoustic stimuli with no-relevant temporal information increased with age. Results are discussed in terms of the current model of the ASSR generation and analysis procedures. They might have implications for audiometric tests designed to assess hearing in subjects who cannot provide reliable results in the psychophysical trials.

Association between temporal resolution and Specific Language Impairment: The role of nonsensory processing.

INTRODUCTION: Many authors have suggested that a perceptual auditory disorder involving temporal processing is the primary cause of Specific Language Impairment (SLI). The aim of this study was to compare the performance of children with and without SLI on a temporal processing task controlling for the confounding of verbal short-term memory and working memory. METHOD: Thirty participants with SLI aged 6 years were selected, along with 30 age- and gender-matched participants with typical language development. The Adaptive Test of Temporal Resolution (ATTR) was used to evaluate temporal resolution ability (an aspect of temporal processing), and the digit span subtest of the Wechsler Intelligence Scale for Children was used to evaluate auditory short-term memory and working memory. RESULTS: The analysis of covariance showed that children with SLI performed significantly worse than children with typical language development on the temporal resolution task (ATTR), even when controlling for short-term memory and working memory. Statistically significant correlations between ATTR and digit span were found for the group of children with SLI but not for the children with typical language development. CONCLUSION: Children with SLI showed significantly worse temporal resolution ability than their peers with typical language development. Such differences cannot be attributed solely to the immediate memory deficit associated with SLI.

The hemodynamic response to acoustically modified syllables in premature and full term newborn infants acquired by near infrared spectroscopy / Respuesta hemodinámica a sílabas modificadas acústicamente en recién nacidos prematuros y a término adquirida por espectroscopía del infrarrojo cercano / Resposta hemodinâmica a sílabas modificadas acusticamente em recém-nascidos prematuros e a termo adquirida por espectroscopia do infravermelho próximo

This research assesses, in newborns, the hemodynamic response to acoustically modified syllables (pronounced in a prolonged manner), versus the response to unmodified syllables (pronounced at a normal rate). The aim was to assess which of these stimulation conditions produced better syllable discrimination in two groups of neonates: 13 preterm (mean gestational age 30 weeks, SD 3 weeks), and 13 full term newborns (mean age 38 weeks, SD 1 week). Syllable discrimination, in each condition, was assessed by using an oddball paradigm (equal syllable trials vs. different syllable trials). The statistical analysis was based on the comparison between the hemodynamic response [oxyHbO] obtained by Near Infrared Spectroscopy (NIRS) to different syllable trials vs. equal syllable trials, in each condition. The modified syllable condition was better in producing trial discrimination in both groups. The amplitude of the hemodynamic response to the different syllable trials was greater than the one to the equal syllable trials: for term infants, t = 2.59, p = 0.024, and for preterm t = 2.38, p = 0.035. This finding occurred in the left temporal lobe. These data suggest that the modified syllables facilitate processing of phonemes from birth.

Esta investigación evalúa, en neonatos, la respuesta hemodinámica ante sílabas modificadas acústicamente (pronunciadas de manera prolongada) en comparación con la respuesta a sílabas no modificadas (pronunciadas a una velocidad normal). El objetivo fue evaluar cuál de estas condiciones de estimulación producía una mejor discriminación silábica en dos grupos de neonatos: 13 prematuros (edad gestacional promedio de 30 semanas, DE 3 semanas) y 13 nacidos a término (edad gestacional promedio de 38 semanas, DE 1 semana). La discriminación de sílabas, en cada condición, se evaluó mediante un paradigma oddball (ensayos con sílabas iguales vs. ensayos con sílaba diferente). El análisis estadístico se basó en la comparación de la respuesta hemodinámica [oxyHb] obtenida por espectroscopia de infrarrojo cercano (NIRS) ante ensayos con sílabas iguales Vs. ensayos con una sílaba diferente en cada condición. Se encontró que la condición de sílabas modificadas obtuvo mejores resultados para la discriminación entre ensayos en ambos grupos. La amplitud de la respuesta hemodinámica ante el ensayo con una sílaba diferente fue significativamente mayor que ante el ensayo con sílabas iguales: en recién nacidos a término, t = 2,59, p = 0,024 y en los prematuros, t = 2,38, p = 0,035. Este hallazgo ocurrió en el lóbulo temporal izquierdo. Estos datos sugieren que las sílabas modificadas facilitan el procesamiento de fonemas desde el nacimiento.

Esta pesquisa avalia, em neonatos, a resposta hemodinâmica diante sílabas modificadas acusticamente (pronunciadas de maneira prolongada) em comparação com a resposta a sílabas não modificadas (pronunciadas a uma velocidade normal). O objetivo foi avaliar qual destas condições de estimulação produzia uma melhor discriminação silábica em dois grupos de neonatos: 13 prematuros (idade gestacional média de 30 semanas, DE 3 semanas) e 13 nascidos a termo (idade gestacional média de 38 semanas, DE 1 semana). A discriminação de sílabas, em cada condição, foi avaliada mediante um paradigma oddball (ensaios com sílabas iguais vs. ensaios com sílaba diferente). A análise estadística se baseou na comparação da resposta hemodinâmica [oxyHb] obtida por espectroscopia de infravermelho próximo (NIRS) ante ensaios com sílabas iguais Vs. ensaios com uma sílaba diferente em cada condição. Encontrou-se que a condição de sílabas modificadas obteve melhores resultados para a discriminação entre ensaios em ambos os grupos. A amplitude da resposta hemodinâmica ante o ensaio com uma sílaba diferente foi significativamente maior que perante o ensaio com sílabas iguais: em recém-nascidos a termo, t = 2,59, p = 0,024 e nos prematuros, t = 2,38, p = 0,035. Este descobrimento ocorreu no lóbulo temporal esquerdo. Estes dados sugerem que as sílabas modificadas facilitam o processamento de fonemas desde o nascimento.

Estructuras cerebrales implicadas en el procesamiento temporal / Brain structures involved in temporal processing

El tiempo siempre ha sido una constante regulatoria del comportamiento humano. Durante las últimas dos décadas, la neurociencia ha buscado las bases biológicas al igual que la localización específica de estructuras o sistemas que el cerebro humano utilice en la ejecución, interpretación o retención de procesamientos temporales. La presente revisión reúne gran parte de los estudios actuales enfocados en la ubicación de las estructuras que involucran lapsos de retención, cronometraje o procesamiento temporal, reportando evidencia respecto a diversas estructuras involucradas, como lo son los ganglios basales; en la activación del putamen respecto a conteos dentro de respuestas motoras; Al cerebelo, en relación a intervalos de duración relativamente breves de tiempo, que van desde 300, 400, 600 y 800 ms, hasta 1-2 o 12-24 segundos; En la relación entre amígdala y corteza insular, en la ejecución de cronometraje controlado; En corteza frontal/pre-frontal, asociado a períodos breves (menores a 1 s) o al menor rendimiento de procesos atencionales o de memoria, propios del funcionamiento ejecutivo; y corteza parietal, asociada a la comparación consiente de las duraciones en rango de segundos (intervalos de 1 s) en relación a señales auditivas y visuales, así como en la codificación espacial y el procesamiento de cantidades numéricas. La localización de estas estructuras es la base para el desarrollo de modelos de estudio e integración de sistemas cada vez más precisos respecto a cómo el cerebro humano interpreta el tiempo...

Time has always been a constant regulatory human behavior. During the past two decades, neuroscience has sought the biological basis as the specific location of structures or systems that use the human brain in the execution, interpretation or retention of time processing. The present revision gathers much of the current research focused on the location of structures that involve retention periods, timing or temporal processing, reporting evidence regarding various structures involved, such as the basal ganglia, in the putamen regarding activation counts within motor responses; The cerebellum, in relation to a relatively short duration intervals of time, ranging from 300, 400, 600 and 800 ms, 1-2 or 12-24 seconds; In the relationship between amygdale and insular cortex, in performing timing control; In frontal/prefrontal cortex, associated with brief periods (less than 1-s) or lower yield of attention or memory processing, typical of executive functioning; And parietal cortex associated consents comparison of durations in seconds range (1-s intervals) in relation to auditory and visual cues, as well as spatial encoding and processing numerical quantities. The location of these structures is the basis for the development of study models and integration systems increasingly accurate as to how the human brain interprets the time...

Auditory temporal processing deficits and language disorders in patients with neurofibromatosis type 1.

UNLABELLED: Previous findings from a case report led to the argument of whether other patients with neurofibromatosis type 1 (NF1) may have abnormal central auditory function, particularly auditory temporal processing. We hypothesized that it is associated with language and learning disabilities in this population. The aim of this study was to measure central auditory temporal function in NF1 patients and correlate it with the results of language evaluation tests. A descriptive/comparative study including 25 NF1 individuals and 22 healthy controls compared their performances on audiometric evaluation and auditory behavioral testing (Sequential Verbal Memory, Sequential Non-Verbal Memory, Frequency Pattern, Duration Pattern, and Gaps in Noise Tests). To assess language performance, two tests (phonological and syntactic awareness) were also conducted. The study showed that all participants had normal peripheral acoustic hearing. Differences were found between the NF1 and control groups in the temporal auditory processing tests [Sequential Verbal Memory (P=0.009), Sequential Non-Verbal Memory (P=0.028), Frequency Patterns (P=0.001), Duration Patterns (P=0.000), and Gaps in Noise (P=0.000)] and in language tests. The results of Pearson correlation analysis demonstrated the presence of positive correlations between the phonological awareness test and Frequency Patterns humming (r=0.560, P=0.001), Frequency Patterns labeling (r=0.415, P=0.022) and Duration Pattern humming (r=0.569, P=0.001). These results suggest that the neurofibromin deficiency found in NF1 patients is associated with auditory temporal processing deficits, which may contribute to the cognitive impairment, learning disabilities, and attention deficits that are common in this disorder. LEARNING OUTCOMES: The reader will be able to: (1) describe the auditory temporal processing in patients with neurofibromatosis type 1; and (2) describe the impact of the auditory temporal deficits in language in this population.

Facilitatory effects of an auditory warning stimulus in a visual location identification task and a visual shape identification task

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.

Efectos de la edad sobre el procesamiento auditivo / Effect of aging on auditory processing

En la actualidad existe un cúmulo de información teórica y experimental sobre los cambios de la percepción del habla relacionado con las edades. Se ha establecido que esta dificultad en la comunicación producto de la edad se debería a tres grandes factores; a) déficit de las habilidades cognitivas, b) cambios en la función auditiva periférica y c) cambios en una o más de las funciones auditivas centrales. Si bien es cierto la pérdida auditiva generada con la edad (presbiacusia) es responsable en parte de estas dificultades, no es posible atribuirle a solo este factor los déficits observados en poblaciones de mayor edad. Es posible evidenciar alteraciones en la representación neural de la información acústica, en especial cuando asta es de mayor complejidad como lo podría ser el habla, a su vez tambi6n es posible observar alteraciones en las funciones auditivas y esto evidenciado a través de las pruebas conductuales, como aquellas que utilizan el escucha dicótica. Por lo anterior es importante considerar estos efectos al momento de planificar el proceso de rehabilitación de un adulto mayor.

There is theoretical and experimental information on changes in speech perception related to the age. It has been established that this dufficulty in communication due to aging is due to three main factors: a) cognitive skills, b) changes in peripheral auditory function and c) changes in one or more of the central auditory functions. Although hearing loss generated with age (presbycusis) is partly responsible for these difficulties is not possible to attribute to this factor alone deficits observed in older populations. It is possible for alterations in the neural representation of acoustic information especially when it is more complex as speech, it is also possible to observe changes in auditory functions evidenced through behavioral tests such as those using dichotic listening. Therefore it is important to consider these effects when planning the rehabilitation in elderly.

Processamento temporal: sua importância para a aprendizagem da leitura / xxx

Apesar das vastas pesquisas que buscam compreender os problemas de leitura e as causas a eles subjacentes, ainda há alguns aspectos em aberto. Por essa razão, buscou-se com a presente pesquisa analisar a relação entre o processamento temporal e a leitura. Para tanto, inicialmente, foram avaliadas 184 crianças de 2º, 3º e 4º anos do ensino fundamental e, com base nos desempenhos em uma prova de leitura, foram selecionados dois grupos com 26 crianças cada: um grupo de bons leitores e um grupo de maus leitores. Esses dois grupos foram submetidos a testes individuais para avaliar três habilidades de processamento temporal, a saber, o ritmo (em termos de produção motora espontânea, reprodução de estruturas rítmicas e compreensão de notação simbólica); a velocidade (de leitura, de nomeação de figuras e números); o sequenciamento (memória de sons verbais e sequenciamento de atividades cotidianas). Análises de variância foram conduzidas para verificar possíveis diferenças significativas entre os grupos e os anos escolares. De forma geral, o grupo de maus leitores apresentou desempenho rebaixado em diversas tarefas de processamento temporal quando comparadas com o grupo de bons leitores, sendo tal rebaixamento mais evidente nas tarefas de velocidade de leitura e de nomeação. Houve, também, correlação entre leitura e vários aspectos do processamento temporal. Tais resultados sugerem que problemas de leitura estão relacionados a déficits temporais, principalmente em tarefas que envolvem material verbal, tais como a velocidade de leitura e de nomeação.(AU)

Despite extensive research seeking to understand the problems of reading and the causes underlying them, there are still some open aspects. Therefore, it was with this research examining the relationship between temporal processing and reading. For both were initially evaluated 184 children of 2, 3 and 4 grades of elementary school and, based on performance on a reading test, it was selected two groups with 26 children each, a group of good readers and a group of poor readers. These two groups were subjected to three tests to assess individual abilities of temporal processing, namely the rhythm (in terms of spontaneous motor production, reproduction of rhythmic structures and understanding of symbolic notation), the speed (readinf speed, picture naming speed and number naming speed) and sequencing (memory of verbal sounds and sequencing of daily activities). Analysis of variance was conducted to check possible differences between groups and school years. Overall, the group of poor readers showed lower performance on several tasks of temporal processing when compared with the group of good readers. This lower performance is more apparent in the tasks of reading speed and naming. There was also correlation between reading and various aspects of temporal processing. These results suggest that problems with reading are related to temporal deficits, especially on tasks involving verbal material, such as speed reading and naming.(AU)

Lateral interactions in visual perception of temporal signals: cortical and subcortical components

The aim of this work was to isolate and investigate subcortical and cortical lateral interactions involved in flicker perception. We quantified the perceived flicker strength (PFS) in the center of a test stimulus which was simultaneously modulated with a surround stimulus (50 percent Michelson contrast in both stimuli). Subjects were requested to adjust the modulation depth of a separate matching stimulus that was physically identical to the center of the test stimulus but without the surround. Using LCD goggles, synchronized to the frame rate of a CRT screen, the center and surround could be presented monoptically or dichoptically. In the monoptic condition, center-surround interactions can have both subcortical and cortical origins. In the dichoptic condition, center-surround interactions cannot occur in the retina and the LGN, therefore isolating a cortical mechanism. Results revealed both a strong monoptic (subcortical plus cortical) lateral interaction and a weaker dichoptic (cortical) lateral interaction. Subtraction of the dichoptic from the monoptic data revealed a subcortical mechanism of the lateral interaction. While the modulation of the cortical PFS component showed a low-pass temporal-frequency tuning, the modulation of the subcortical PFS component was maximal at 6 Hz. These findings are consistent with two separate temporal channels influencing the monoptic PFS, each with distinct lateral interactions strength and frequency tuning characteristics. We conclude that both subcortical and cortical lateral interactions modulate flicker perception.(AU)

Lateral interactions in visual perception of temporal signals: cortical and subcortical components

The aim of this work was to isolate and investigate subcortical and cortical lateral interactions involved in flicker perception. We quantified the perceived flicker strength (PFS) in the center of a test stimulus which was simultaneously modulated with a surround stimulus (50 percent Michelson contrast in both stimuli). Subjects were requested to adjust the modulation depth of a separate matching stimulus that was physically identical to the center of the test stimulus but without the surround. Using LCD goggles, synchronized to the frame rate of a CRT screen, the center and surround could be presented monoptically or dichoptically. In the monoptic condition, center-surround interactions can have both subcortical and cortical origins. In the dichoptic condition, center-surround interactions cannot occur in the retina and the LGN, therefore isolating a cortical mechanism. Results revealed both a strong monoptic (subcortical plus cortical) lateral interaction and a weaker dichoptic (cortical) lateral interaction. Subtraction of the dichoptic from the monoptic data revealed a subcortical mechanism of the lateral interaction. While the modulation of the cortical PFS component showed a low-pass temporal-frequency tuning, the modulation of the subcortical PFS component was maximal at 6 Hz. These findings are consistent with two separate temporal channels influencing the monoptic PFS, each with distinct lateral interactions strength and frequency tuning characteristics. We conclude that both subcortical and cortical lateral interactions modulate flicker perception.

How auditory temporal processing deficits relate to dyslexia

Studies have shown that dyslexic children present a deficiency in the temporal processing of auditory stimuli applied in rapid succession. However, discussion continues concerning the way this deficiency can be influenced by temporal variables of auditory processing tests. Therefore, the purpose of the present study was to analyze by auditory temporal processing tests the effect of temporal variables such as interstimulus intervals, stimulus duration and type of task on dyslexic children compared to a control group. Of the 60 children evaluated, 33 were dyslexic (mean age = 10.5 years) and 27 were normal controls (mean age = 10.8 years). Auditory processing tests assess the abilities of discrimination and ordering of stimuli in relation to their duration and frequency. Results showed a significant difference in the average accuracy of control and dyslexic groups considering each variable (interstimulus intervals: 47.9 ± 5.5 vs 37.18 ± 6.0; stimulus duration: 61.4 ± 7.6 vs 50.9 ± 9.0; type of task: 59.9 ± 7.9 vs 46.5 ± 9.0) and the dyslexic group demonstrated significantly lower performance in all situations. Moreover, there was an interactive effect between the group and the duration of stimulus variables for the frequency-pattern tests, with the dyslexic group demonstrating significantly lower results for short durations (53.4 ± 8.2 vs 48.4 ± 11.1), as opposed to no difference in performance for the control group (62.2 ± 7.1 vs 60.6 ± 7.9). These results support the hypothesis that associates dyslexia with auditory temporal processing, identifying the stimulus-duration variable as the only one that unequally influenced the performance of the two groups.