Visual Spatial Memory in Young Typical Developing Children and Children with Developmental Language Disorder: A Pilot Study

This pilot study aimed to examine nonlinguistic deficits associated with visual spatial memory in young children. A child with DLD was compared to both younger-aged (YATD) and same-aged (SATD) typically developing peers for performance on a visual spatial memory matching game. It was hypothesized that if children with DLD have deficits in nonlinguistic domains, they should not perform as well as their same-aged peers. Since children with DLD are similar in language to their younger typically developing children, their performance was compared to a group of typically developing children at least one year younger. If children with DLD performed less well than same-aged children, we were curious to see if they would be similar to the younger children. A total of 6 children (ages 3;2 to 4;9) were recruited from the Storrs, Connecticut area. The children were placed into one of three groups (DLD, YATD, or SATD) based on their age and performance on the Clinical Evaluation of Language Fundamentals - Preschool (CELF-P). One child was identified with DLD (age 4;8), three children served as SATD controls (ages 4;0-4;9), and two children served as YATD controls (ages 3;2-3;5). Each child played the iPad game, Animal Matching 4 Kid - Memory Game for Preschool, ten times. Performance was measured by the score obtained at the end of each trial of the game and then averaged over the 10 trials for each group. Results revealed that the SATD group obtained the highest average score (m=89.9), followed by the YATD group (m=79.6), and lastly the child with DLD (m=66.1). The trend demonstrated age and language ability as contributing factors to the children’s scores. These findings imply that visual spatial memory may be problematic for children with DLD. Further research must be conducted, but these findings hold strong implications for clinical practice and a potential link between DLD and visual spatial working memory

The Nature of Working Memory in Aphasia

Thesis (PhD) - Indiana University, Speech and Hearing, 2007It is well known that many adults with aphasia demonstrate concomitant deficits in higher-level cognitive functions, including attention, executive function, and short-term and working memory. This has led to two premises: (a) the domain-specific hypothesis, in which aphasia is associated with additional cognitive deficits only to the extent that these are dependent upon language; and (b) the domain-general hypothesis, in which aphasia is associated with nonlinguistic cognitive impairments as a consequence of either overlapping anatomy or widespread cortical changes post-insult. The purpose of this research was to disentangle these competing hypotheses with regards to working memory (WM) in adults with aphasia. Like other categories of cognitive impairment in this patient group, past research has identified but failed to elucidate WM impairments in aphasic language processing. Toward this end, 15 adults with left-hemisphere damage and aphasia (LHD) and 12 non-brain-damaged controls (NBD) completed a parametric WM task with systematic variation of psycholinguistic complexity (high-frequency, low-frequency, or non-nameable stimuli) and WM load (0-, 1-, and 2-back). Data were analyzed with respect to the differential impact of these variables within and across subjects and groups. Whereas expected effects of word frequency were elicited in stimulus confrontation naming, LHD subjects were affected only minimally by frequency manipulations during the n-back task. Instead, these subjects demonstrated a significant performance decrement relative to controls with increasing WM load. Moreover, aphasia severity was moderately correlated with WM for non-nameable (i.e., more difficult) but not nameable stimuli. At the theoretical level, these results support a resource-based processing model in aphasia; at the neurobiological level, these findings are consistent with the proposition of widespread cortical connectivity changes irrespective of type or location of brain damage. A secondary purpose of this study was to investigate the reliability of LHD performance on the n-back task, given the known performance variability associated with aphasia and the general dearth of reliability data for higher-level tasks. Results demonstrated that the n-back task is a reliable WM indicator over time for this population

Name agreement in picture naming: An ERP study

Name agreement is the extent to which different people agree on a name for a particular picture. Previous studies have found that it takes longer to name low name agreement pictures than high name agreement pictures. To examine the effect of name agreement in the online process of picture naming, we compared event-related potentials (ERPs) recorded whilst 19 healthy, native English speakers silently named pictures which had either high or low name agreement. A series of ERP components was examined: P1 approximately 120ms from picture onset, N1 around 170ms, P2 around 220ms, N2 around 290ms, and P3 around 400ms. Additionally, a late time window from 800 to 900ms was considered. Name agreement had an early effect, starting at P1 and possibly resulting from uncertainty of picture identity, and continuing into N2, possibly resulting from alternative names for pictures. These results support the idea that name agreement affects two consecutive processes: first, object recognition, and second, lexical selection and/or phonological encoding

Concepts As Correlates Of Lexical Items

The content of this article amounts to a somewhat controversial terminological proposal: the term ‘concept’ is most fruitfully construed as ‘a mental representations having a lexical correlate’. Such a definition makes it possible to treat ‘concept’ as a technical term across the cognitive sciences, but also preserving most intuitions from a looser use of this word in the literature. The central points consist in a) appreciating the qualitative difference between the mental representations correlated with lexical labels and other mental representations, and b) accepting this difference as an effect of the causal influence of language on cognition. The argument is supported by a review of recent empirical results

An integrated theory of language production and comprehension

Currently, production and comprehension are regarded as quite distinct in accounts of language processing. In rejecting this dichotomy, we instead assert that producing and understanding are interwoven, and that this interweaving is what enables people to predict themselves and each other. We start by noting that production and comprehension are forms of action and action perception. We then consider the evidence for interweaving in action, action perception, and joint action, and explain such evidence in terms of prediction. Specifically, we assume that actors construct forward models of their actions before they execute those actions, and that perceivers of others' actions covertly imitate those actions, then construct forward models of those actions. We use these accounts of action, action perception, and joint action to develop accounts of production, comprehension, and interactive language. Importantly, they incorporate well-defined levels of linguistic representation (such as semantics, syntax, and phonology). We show (a) how speakers and comprehenders use covert imitation and forward modeling to make predictions at these levels of representation, (b) how they interweave production and comprehension processes, and (c) how they use these predictions to monitor the upcoming utterances. We show how these accounts explain a range of behavioral and neuroscientific data on language processing and discuss some of the implications of our proposal

Brain circuit for cognitive control is shared by task and language switching

Controlling multiple languages during speech production is believed to rely on functional mechanisms that are (at least partly) shared with domain-general cognitive control in early, highly proficient bilinguals. Recent neuroimaging results have indeed suggested a certain degree of neural overlap between language control and nonverbal cognitive control in bilinguals. However, this evidence is only indirect. Direct evidence for neural overlap between language control and nonverbal cognitive control can only be provided if two prerequisites are met: Language control and nonverbal cognitive control should be compared within the same participants, and the task requirements of both conditions should be closely matched. To provide such direct evidence for the first time, we used fMRI to examine the overlap in brain activation between switch-specific activity in a linguistic switching task and a closely matched nonlinguistic switching task, within participants, in early, highly proficient Spanish-Basque bilinguals. The current findings provide direct evidence that, in these bilinguals, highly similar brain circuits are involved in language control and domaingeneral cognitive control

Towards a complete multiple-mechanism account of predictive language processing [Commentary on Pickering & Garrod]

Although we agree with Pickering & Garrod (P&G) that prediction-by-simulation and prediction-by-association are important mechanisms of anticipatory language processing, this commentary suggests that they: (1) overlook other potential mechanisms that might underlie prediction in language processing, (2) overestimate the importance of prediction-by-association in early childhood, and (3) underestimate the complexity and significance of several factors that might mediate prediction during language processing

Mechanisms of memory retrieval in slow-wave sleep : memory retrieval in slow-wave sleep

Study Objectives: Memories are strengthened during sleep. The benefits of sleep for memory can be enhanced by re-exposing the sleeping brain to auditory cues; a technique known as targeted memory reactivation (TMR). Prior studies have not assessed the nature of the retrieval mechanisms underpinning TMR: the matching process between auditory stimuli encountered during sleep and previously encoded memories. We carried out two experiments to address this issue. Methods: In Experiment 1, participants associated words with verbal and non-verbal auditory stimuli before an overnight interval in which subsets of these stimuli were replayed in slow-wave sleep. We repeated this paradigm in Experiment 2 with the single difference that the gender of the verbal auditory stimuli was switched between learning and sleep. Results: In Experiment 1, forgetting of cued (vs. non-cued) associations was reduced by TMR with verbal and non-verbal cues to similar extents. In Experiment 2, TMR with identical non-verbal cues reduced forgetting of cued (vs. non-cued) associations, replicating Experiment 1. However, TMR with non-identical verbal cues reduced forgetting of both cued and non-cued associations. Conclusions: These experiments suggest that the memory effects of TMR are influenced by the acoustic overlap between stimuli delivered at training and sleep. Our findings hint at the existence of two processing routes for memory retrieval during sleep. Whereas TMR with acoustically identical cues may reactivate individual associations via simple episodic matching, TMR with non-identical verbal cues may utilise linguistic decoding mechanisms, resulting in widespread reactivation across a broad category of memories

Visual event-related potentials to colored patterns and color names : attention to feature, dimension, and meaning

The present study utilized visual event-related brain responses to investigate the nature of representation of colors and color names in the nervous system. It was hypothesized that the initial processing of sensory colors and linguistic stimuli occurs at different levels of the brain, while later in time, these features may be synthesized into a unitary representation (e.g. sensory color along with its linguistic label) in central cortical regions. A final prediction was that the processing of sensory colors would elicit greater responses over the right hemisphere while the processing of word stimuli would elicit greater enhancement of the brain response over the left hemisphere