Prosodic Similarity Effects in Short-Term Memory in Developmental Dyslexia.

Children with developmental dyslexia are characterized by phonological difficulties across languages. Classically, this 'phonological deficit' in dyslexia has been investigated with tasks using single-syllable words. Recently, however, several studies have demonstrated difficulties in prosodic awareness in dyslexia.

Neural encoding of the speech envelope by children with developmental dyslexia.

Developmental dyslexia is consistently associated with difficulties in processing phonology (linguistic sound structure) across languages. One view is that dyslexia is characterised by a cognitive impairment in the "phonological representation" of word forms, which arises long before the child presents with a reading problem. Here we investigate a possible neural basis for developmental phonological impairments.

Attentional Selection in a Cocktail Party Environment Can Be Decoded from Single-Trial EEG.

How humans solve the cocktail party problem remains unknown. However, progress has been made recently thanks to the realization that cortical activity tracks the amplitude envelope of speech. This has led to the development of regression methods for studying the neurophysiology of continuous speech.

Neural entrainment to rhythmic speech in children with developmental dyslexia.

A rhythmic paradigm based on repetition of the syllable "ba" was used to study auditory, visual, and audio-visual oscillatory entrainment to speech in children with and without dyslexia using EEG. Children pressed a button whenever they identified a delay in the isochronous stimulus delivery (500 ms; 2 Hz delta band rate). Response power, strength of entrainment and preferred phase of entrainment in the delta and theta frequency bands were compared between groups.

Erratum: Neural entrainment to rhythmically-presented auditory, visual and audio-visual speech in children.

[This corrects the article on p. 216 in vol. 3, PMID: 22833726.

Endogenous auditory frequency-based attention modulates electroencephalogram-based measures of obligatory sensory activity in humans.

Auditory selective attention is the ability to enhance the processing of a single sound source, while simultaneously suppressing the processing of other competing sound sources. Recent research has addressed a long-running debate by showing that endogenous attention produces effects on obligatory sensory responses to continuous and competing auditory stimuli. However, until now, this result has only been shown under conditions where the competing stimuli differed in both their frequency characteristics and, importantly, their spatial location.

The effects of attention and visual input on the representation of natural speech in EEG.

Traditionally, the use of electroencephalography (EEG) to study the neural processing of natural stimuli in humans has been hampered by the need to repeatedly present discrete stimuli. Progress has been made recently by the realization that cortical population activity tracks the amplitude envelope of speech stimuli. This has led to studies using linear regression methods which allow the presentation of continuous speech.

Neural entrainment to rhythmically presented auditory, visual, and audio-visual speech in children.

Auditory cortical oscillations have been proposed to play an important role in speech perception. It is suggested that the brain may take temporal "samples" of information from the speech stream at different rates, phase resetting ongoing oscillations so that they are aligned with similar frequency bands in the input ("phase locking"). Information from these frequency bands is then bound together for speech perception.

At what time is the cocktail party? A late locus of selective attention to natural speech.

Distinguishing between speakers and focusing attention on one speaker in multi-speaker environments is extremely important in everyday life. Exactly how the brain accomplishes this feat and, in particular, the precise temporal dynamics of this attentional deployment are as yet unknown. A long history of behavioral research using dichotic listening paradigms has debated whether selective attention to speech operates at an early stage of processing based on the physical characteristics of the stimulus or at a later stage during semantic processing.

Comparing linear and quadratic models of the human auditory system using EEG.

Recent studies have highlighted the importance of system identification as an approach for assessing sensory processing in humans using electroencephalography (EEG). These studies typically use linear impulse response estimates of visual and, more recently, auditory function. These methods, which are known as the VESPA and AESPA (Visual/Auditory Evoked Spread Spectrum Analysis) respectively, have been found to be useful for studying sensory processing in both healthy populations and clinical groups and for studying the effects of cognition on sensory processing.

Endogenous auditory spatial attention modulates obligatory sensory activity in auditory cortex.

Endogenous attention is the self-directed focus of attention to a region or feature of the environment. In this study, we assess the effects of endogenous attention on temporally detailed responses to continuous and competing auditory stimuli obtained using the novel auditory evoked spread spectrum analysis (AESPA) method. There is some debate as to whether an enhancement of sensory processing is involved in endogenous attention.

Resolving precise temporal processing properties of the auditory system using continuous stimuli.

In natural environments complex and continuous auditory stimulation is virtually ubiquitous. The human auditory system has evolved to efficiently process an infinity of everyday sounds, which range from short, simple bursts of noise to signals with a much higher order of information such as speech. Investigation of temporal processing in this system using the event-related potential (ERP) technique has led to great advances in our knowledge.

Eliciting audio evoked potentials using continuous stimuli.

Noise input signals are commonly used in both linear and non-linear system identification of physiological systems. This method can be applied to electrophysiological analysis of the human auditory system by controlling the modulation of the amplitude of a sound stimulus using a precomputed noise signal. In this study we describe how one can obtain an estimate of the linear response of the auditory system using noise signals and we compare it to a standard auditory evoked potential (AEP).

Can visual evoked potentials be used in biometric identification?

Due to known differences in the anatomical structure of the visual pathways and generators in different individuals, the use of visual evoked potentials offers the possibility of an alternative to existing biometrics methods. A study based on visual evoked potentials from 13 individuals was carried out to assess the best combination of temporal, spectral and AR modeling features to realize a robust biometric. From the results it can be concluded that visual evoked potentials show considerable biometric qualities, with classification accuracies reaching a high of 86.

Genetic sex determination, gender identification and pseudohermaphroditism in the knobbed whelk, Busycon carica (Mollusca: Melongenidae).

We report perhaps the first genic-level molecular documentation of a mammalian-like 'X-linked' mode of sex determination in molluscs. From family inheritance data and observed associations between sex-phenotyped adults and genotypes in Busycon carica, we deduce that a polymorphic microsatellite locus (bc2.2) is diploid and usually heterozygous in females, hemizygous in males, and that its alleles are transmitted from mothers to sons and daughters but from fathers to daughters only.