A comparison of structural morphometry in children and adults with persistent developmental stuttering.

This cross-sectional study aimed to differentiate earlier occurring neuroanatomical differences that may reflect core deficits in stuttering versus changes associated with a longer duration of stuttering by analysing structural morphometry in a large sample of children and adults who stutter and age-matched controls. Whole-brain T-weighted structural scans were obtained from 166 individuals who stutter (74 children, 92 adults; ages 3-58) and 191 controls (92 children, 99 adults; ages 3-53) from eight prior studies in our laboratories. Mean size and gyrification measures were extracted using FreeSurfer software for each cortical region of interest.

Do Not Cut Off Your Tail: A Mega-Analysis of Responses to Auditory Perturbation Experiments.

Purpose: The practice of removing "following" responses from speech perturbation analyses is increasingly common, despite no clear evidence as to whether these responses represent a unique response type. This study aimed to determine if the distribution of responses to auditory perturbation paradigms represents a bimodal distribution, consisting of two distinct response types, or a unimodal distribution.

Method: This mega-analysis pooled data from 22 previous studies to examine the distribution and magnitude of responses to auditory perturbations across four tasks: adaptive pitch, adaptive formant, reflexive pitch, and reflexive formant.

Improvements in Speech of Children with Apraxia: The Efficacy of Treatment for Establishing Motor Program Organization (TEMPO).

: This study investigated the efficacy of Treatment for Establishing Motor Program Organization (TEMPO) in childhood apraxia of speech (CAS). A mixed between- and within-participant design with multiple baselines across participants and behaviors was used to examine acquisition, generalization, and maintenance of skills. TEMPO was administered in four one-hour sessions a week over a four-week period for eleven participants (ages 5 to 8), allocated to either an immediate treatment group or a wait-list control group.

Modelling speech motor programming and apraxia of speech in the DIVA/GODIVA neurocomputational framework.

Background: The Directions Into Velocities of Articulators (DIVA) model and its partner, the Gradient Order DIVA (GODIVA) model, provide neurobiologically grounded, computational accounts of speech motor control and motor sequencing, with applications for the study and treatment of neurological motor speech disorders.

Aims: In this review, we provide an overview of the DIVA and GODIVA models and how they explain the interface between phonological and motor planning systems to build on previous models and provide a mechanistic accounting of apraxia of speech (AOS), a disorder of speech motor programming.

Main Contribution: Combined, the DIVA and GODIVA models account for both the segmental and suprasegmental features that define AOS via damage to (i) a speech sound map, hypothesized to reside in left ventral premotor cortex, (ii) a phonological content buffer hypothesized to reside in left posterior inferior frontal sulcus, and/or (iii) the axonal projections between these regions.

Neural substrates of verbal repetition deficits in primary progressive aphasia.

In this cross-sectional study, we examined the relationship between cortical thickness and performance on several verbal repetition tasks in a cohort of patients with primary progressive aphasia in order to test predictions generated by theoretical accounts of phonological working memory that predict phonological content buffers in left posterior inferior frontal sulcus and supramarginal gyrus. Cortical surfaces were reconstructed from magnetic resonance imaging scans from 42 participants diagnosed with primary progressive aphasia. Cortical thickness was measured in a set of anatomical regions spanning the entire cerebral cortex.

Integration of memory content in adults and children: Developmental differences in task conditions and functional consequences.

How separate yet related episodes of experience are associated in memory is a major question in cognitive science and cognitive neuroscience. Adults and children both integrate content acquired in separate episodes, yet they may do so under different task conditions. Neuroimaging studies suggest that adults integrate the contents of separate memory traces at encoding and thus without an explicit prompt; behavioral studies suggest that children do so only when specifically prompted.

Speech and Gesture Production Provide Unique Insights Into Young Children's Spatial Reasoning.

This study took a novel approach to understanding the role of language in spatial development by combining approaches from spatial language and gesture research. It analyzed forty-three 4.5- to 6-year-old's speech and gesture production during explanations of reasoning behind performance on Spatial Analogies and Children's Mental Transformation Tasks.

Using eye-tracking to understand relations between visual attention and language in children's spatial skills.

Relations between children's spatial language and spatial skills raise questions regarding whether the effects are unique to language or reflect non-linguistic processes. Different paradigms provided mixed evidence: experimenter-provided language supports spatial performance more than visual cues; however, children's non-verbal attention predicts their spatial performance more than their language production. The current study used eye-tracking during spatial recall to compare effects of language versus visual cues.

Children's attention to task-relevant information accounts for relations between language and spatial cognition.

Children's spatial language reliably predicts their spatial skills, but the nature of this relation is a source of debate. This investigation examined whether the mechanisms accounting for such relations are specific to language use or reflect a domain-general mechanism of selective attention. Experiment 1 examined whether 4-year-olds' spatial skills were predicted by their selective attention or their adaptive language use.

Producing Spatial Words Is Not Enough: Understanding the Relation Between Language and Spatial Cognition.

Prior research has investigated the relation between children's language and spatial cognition by assessing the quantity of children's spatial word production, with limited attention to the context in which children use such words. This study tested whether 4-year-olds children's (N = 41, primarily white middle class) adaptive use of task-relevant language across contexts predicted their spatial skills. Children were presented with a spatial scene description task, four spatial tasks, and vocabulary assessments.

Developmental improvements in the resolution and capacity of visual working memory share a common source.

The nature of visual working memory (VWM) representations is currently a source of debate between characterizations as slot-like versus a flexibly-divided pool of resources. Recently, a dynamic neural field model has been proposed as an alternative account that focuses more on the processes by which VWM representations are formed, maintained, and used in service of behavior. This dynamic model has explained developmental increases in VWM capacity and resolution through strengthening excitatory and inhibitory connections.

Language supports young children's use of spatial relations to remember locations.

Two experiments investigated the role of language in children's spatial recall performance. In particular, we assessed whether selecting an intrinsic reference frame could be improved through verbal encoding. Selecting an intrinsic reference frame requires remembering locations relative to nearby objects independent of one's body (egocentric) or distal environmental (allocentric) cues, and does not reliably occur in children under 5 years of age (Nardini, Burgess, Breckenridge, & Atkinson, 2006).

Different developmental trajectories across feature types support a dynamic field model of visual working memory development.

Research on visual working memory has focused on characterizing the nature of capacity limits as "slots" or "resources" based almost exclusively on adults' performance with little consideration for developmental change. Here we argue that understanding how visual working memory develops can shed new light onto the nature of representations. We present an alternative model, the Dynamic Field Theory (DFT), which can capture effects that have been previously attributed either to "slot" or "resource" explanations.