Brain responses and looking behavior during audiovisual speech integration in infants predict auditory speech comprehension in the second year of life

The use of visual cues during the processing of audiovisual (AV) speech is known to be less efficient in children and adults with language difficulties and difficulties are known to be more prevalent in children from low-income populations. In the present study, we followed an economically diverse group of thirty-seven infants longitudinally from 6–9 months to 14–16 months of age. We used eye-tracking to examine whether individual differences in visual attention during AV processing of speech in 6–9 month old infants, particularly when processing congruent and incongruent auditory and visual speech cues, might be indicative of their later language development. Twenty-two of these 6–9 month old infants also participated in an event-related potential (ERP) AV task within the same experimental session. Language development was then followed-up at the age of 14–16 months, using two measures of language development, the Preschool Language Scale and the Oxford Communicative Development Inventory. The results show that those infants who were less efficient in auditory speech processing at the age of 6–9 months had lower receptive language scores at 14–16 months. A correlational analysis revealed that the pattern of face scanning and ERP responses to audiovisually incongruent stimuli at 6–9 months were both significantly associated with language development at 14–16 months. These findings add to the understanding of individual differences in neural signatures of AV processing and associated looking behavior in infants.

Brain responses to audiovisual speech mismatch in infants are associated with individual differences in looking behaviour

Research on audiovisual speech integration has reported high levels of individual variability, especially among young infants. In the present study we tested the hypothesis that this variability results from individual differences in the maturation of audiovisual speech processing during infancy. A developmental shift in selective attention to audiovisual speech has been demonstrated between 6 and 9 months with an increase in the time spent looking to articulating mouths as compared to eyes (Lewkowicz & Hansen-Tift. (2012) Proc. Natl Acad. Sci. USA, 109, 1431–1436; Tomalski et al. (2012) Eur. J. Dev. Psychol., 1–14). In the present study we tested whether these changes in behavioural maturational level are associated with differences in brain responses to audiovisual speech across this age range. We measured high-density event-related potentials (ERPs) in response to videos of audiovisually matching and mismatched syllables /ba/ and /ga/, and subsequently examined visual scanning of the same stimuli with eye-tracking. There were no clear age-specific changes in ERPs, but the amplitude of audiovisual mismatch response (AVMMR) to the combination of visual /ba/ and auditory /ga/ was strongly negatively associated with looking time to the mouth in the same condition. These results have significant implications for our understanding of individual differences in neural signatures of audiovisual speech processing in infants, suggesting that they are not strictly related to chronological age but instead associated with the maturation of looking behaviour, and develop at individual rates in the second half of the first year of life.

Fast segmentation of 3D data using an octree

The algorithm developed uses an octree pyramid in which noise is reduced at the expense of the spatial resolution. At a certain level an unsupervised clustering without spatial connectivity constraints is applied. After the classification, isolated voxels and insignificant regions are removed by assigning them to their neighbours. The spatial resolution is then increased by the downprojection of the regions, level by level. At each level the uncertainty of the boundary voxels is minimised by a dynamic selection and classification of these, using an adaptive 3D filtering. The algorithm is tested using different data sets, including NMR data.

Analysis of underwater acoustic data via 3-D segmentation

The analysis of seabed structure is important in a wide variety of scientific and industrial applications. In this paper, underwater acoustic data produced by bottom-penetrating sonar (Topas) are analyzed using unsupervised volumetric segmentation, based on a three dimensional Gibbs-Markov model. The result is a concise and accurate description of the seabed, in which key structures are emphasized. This description is also very well suited to further operations, such as the enhancement and automatic recognition of important structures. Experimental results demonstrating the effectiveness of this approach are shown, using Topas data gathered in the North Sea off Horten, Norway.

Speech of Mr. C. G. Memminger, on the question of rechartering the bank of the state of South Carolina: delivered in the House of Representatives, December 9, 1848

This speech by Mr. Memminger offers resolutions on the issue of rechartering the bank of the state of South Carolina. The issues presented are the Bank of the State is founded on an erroneous policy, unwise for a state to engage in banking, not practical to recharter the Bank of the State and a special committee of each house should be appointed to advise how to carry out these resolutions at the next session.

The sectionalism of the tariff bill. Speech of Hon. John L. McLaurin, of South Carolina, in the Senate of the United States

This document contains a speech by John L. McLaurin, representative of South Carolina. Sections of the speech include: sectionalism exposed, the bill might have been defeated, the south plundered of its rights, not a protectionist, fraudulent demands of New England, Hon. Randolph Tucker, Hon. W.R. Morrison, and Hon. R.Q. Mills strangers to the doctrine in 1882, a tariff for revenue against the doctrine of free raw material, don’t want Cleveland’s interpretation, contest of schedules, and my remedy.

Speech of Hon. John Lowndes McLaurin, of South Carolina, in the Senate of the United States, Monday, December 9, 1901

This document contains a speech by John L. McLaurin of South Carolina presented in the Senate of the United States. Sections of the speech include: sectionalism the cause, conditions in South Carolina, the federal administration in South Carolina, should not array class against class, freedom of thought and speech, the issues, under caucus dictation the Senate no longer a deliberative body, the beginning of the fight, matter of arraying class against class, freedom of thought and speech, and issues.

The tariff. Speech of Representative J. L. McLaurin, of South Carolina, in the House of Representatives, Tuesday, March 23, 1897

This document contains a speech of John L. McLaurin, representative of South Carolina, in the House of Representatives on Tuesday, March 23, 1897 about proposed tariffs.

Where the consumer is not a myth : letters from England describing economic and industrial conditions by Zach McGhee, Washington correspondent : speech of Hon. Wyatt Aiken in the House of Representatives, Tuesday, March 22, 1910

This document contains a speech of David Wyatt Aiken, representative of South Carolina, to the House of Representatives on Tuesday, March 22, 1910. Much of the speech is a letter from Zach McGhee, Washington correspondent of The State newspaper on industrial conditions in England and Europe.

Protection to farmers : speech of Hon. D. Wyatt Aiken, of South Carolina, in the House of Representatives, Tuesday, March 6, 1882, upon the Agricultural Appropriation Bill

This speech is about the Agricultural Appropriation Bill, which is a bill making appropriations for the Agricultural Department of the Government for the fiscal year ending in June 30,1883. Mr. Aiken is approved by the chairman to speak and he goes on to explain that he agrees with the majority of the bill with the exception of two or three clauses. He gives the reasoning behind his objections in the rest of the speech.

Speech delivered by Hon. Hermann Ridder at the one hundred and forty-second anniversary dinner, German Friendly Society, Charleston, S. C., January 15th, 1908

The speech was delivered to the German Friendly Society by the Hon. Hermann Ridder and opens with a brief history of the society and its importance. He then goes on to acknowledge notable German settlers and their importance. He calls for history to be rewritten and textbooks to be revised to give credit to the Germans who contributed to America’s foundation and history.

Speech of Hon. James H. Hammond, of South Carolina, on the relation of states; delivered in the Senate of the United States, May 21, 1860

The speech is a response by Hon. James H. Hammond as to whether or not the territorial governments established by Congress have the power to define and declare what shall be and what shall not be property within the territorial boundaries. The speech goes on to discuss colonists who went to newly purchased territory and claimed land as their own. He argues whether or not these people have sovereignty of the land over the government.

Speech of Hon. John Lowndes McLaurin, of South Carolina, in the Senate of the United States, Monday, December 9, 1901

This speech is to address the statement that Mr. McLaurin has been excluded from the caucuses of his party and thus that he will be without assignment on any committee. He goes on to explain his exclusion and defend his views that led to his exclusion.

Speech of Mr. Calhoun, of South Carolina, on the slavery question. Delivered in the Senate of the United States, March 4, 1850

The speech addresses the question, how can the union be preserved? He goes on to explain the threats to the union and give suggestions for how the threats can be handled.