Single Pictures Research Articles

Aphasia Assessment in Chinese Speakers

Aphasia Assessment in Chinese Speakers

Lexical diversity for adults with and without aphasia across discourse elicitation tasks

Background: Differences in lexical diversity (LD) across different discourse elicitation tasks have been found in neurologically intact adults (NIA) (Fergadiotis, Wright, & Capilouto, 2010) but have not been investigated systematically in people with aphasia (PWA). Measuring lexical diversity in PWA may serve as a useful clinical tool for evaluating the impact of word retrieval difficulties at the discourse level. Aims: The study aims were (a) to explore the differences between the oral language samples of PWA and NIA in terms of LD as measured by dedicated computer software (voc-D), (b) to determine whether PWA are sensitive to discourse elicitation task in terms of LD, and (c) to identify whether differences between PWA and NIA vary in magnitude as a function of discourse task. Method & Procedures: Oral language samples from 25 PWA and 27 NIA were analysed. Participants completed three commonly used discourse elicitation tasks (single pictures, sequential pictures, story telling) and voc-D was used to obtain estimates of their LD. Outcomes & Results: A mixed 2 × 3 ANOVA revealed a significant group × task interaction that was followed by an investigation of simple main effects and tetrad comparisons. Different patterns of LD were uncovered for each group. For the NIA group results were consistent with previous findings in the literature according to which LD varies as a function of elicitation technique. However, for PWA sequential pictures and story telling elicited comparable estimates of LD. Conclusions: Results indicated that LD is one of the microlinguistic indices that are influenced by elicitation task and the presence of aphasia. These findings have important implications for modelling lexical diversity and selecting and interpreting results from different discourse elicitation tasks.

Simultaneous determination of the X-ray refractive index and the attenuation length from a single digitally registered radiograph of rectangular prisms

Prisms deflect and disperse X-rays due to refraction very similar to visible light. As X-rays are always attenuated while traversing material, the intensity distribution in the transmitted beam carries information about the prism transmission function. This study will show that sufficient information is contained in a single digitally registered radiograph from a rectangular prism, for deriving both the refractive index of the material and its attenuation length. The measured data can be prepared such that neither intensity fluctuations nor false light content in the incident beam will introduce systematic errors into the result. The strategy is thus very adapted, when single shot pictures are taken at X-ray sources with limited shot reproducibility. This technique is favourably be used at very grazing angles of incidence of the order of the critical angle for the prism material, when the beam deflection becomes significant. In such a geometry dimensional parameters, like sample thickness, do not affect the data analysis, which is particularly insensitive to even significant errors in the tip angle.

Fast Motion Estimation Scheme for H.264/AVC Using Adaptive Single and Multiple Reference Picture Selections

In video coding standard of H.264/AVC, motion estimation (ME) using multiple reference pictures improves compression efficiency considerably. However, the motion estimation includes a large amount of useless computations regardless of picture contents. This paper proposes a fast motion estimation algorithm that removes the worthless computations in the motion estimation process with switching single and multiple reference pictures adaptively. The proposed algorithm classifies blocks into valid and invalid blocks for the multiple references based ME, and removes the unnecessary computations by applying a single reference based ME to the invalid blocks. In order to evaluate the performance of the proposed algorithm, measures with respects to image quality, bit rate, and motion estimation time are compared with those of the scheme in a reference software JM 9.5. The simulation results show that the proposed algorithm can considerably save 39% on average motion estimation time while keeping the image quality (0.025dB degradation) and the bit rate (0.8% decrease) as good as the reference algorithm.

Manipulating task instructions to change narrative discourse performance

Background: A frequent method for eliciting narratives involves presenting picture stimuli and instructing the participant to “tell me what is happening in the picture(s) or tell me everything you see going on in the picture(s)”. It has been suggested that such instructions do not make an explicit request for providing temporal–causal information and so narrative samples frequently comprise listed information. Olness (2006) investigated the effect of task instruction on verb forms produced by adults with aphasia when describing pictures and found that using instructions that explicitly requested temporal–causal information—“Make up your own story about what happened, with a beginning, middle, and an end” (p. 179)—improved the ability of participants to convey the temporal–causal interrelationship depicted in single pictures. Further interpretation of the results was limited due to the lack of non‐brain‐injured participants for comparison. Aims: The purpose of the study was (1) to compare the performance of two groups of healthy older adults on the ability to convey main events in pictured stimuli when different task instructions were provided and (2) to quantify linguistic performance across the two groups and determine if groups significantly differed for any of the linguistic features. Method & Procedures: Participants included 24 healthy older adults assigned to one of two groups based on task instruction: picture description (PD) or storytelling (ST). Instructions were as follows—PD group: “Talk about what is going on in the picture(s)”; ST group: “I want you to look at the picture(s) and tell me a story that has a beginning, middle, and end”. Outcomes & Results: The ST group produced a significantly higher proportion of main events and significantly more past‐tense verbs than the PD group. Two significant relationships among the linguistic measures and main events measure were found for the PD group: a positive relationship between percent of information units (IUs) produced and proportion of main events for the sequential pictures and a negative relationship between D (Malvern & Richards, 1997) and proportion of main events for the single picture stimuli. Conclusions: Findings suggest that task instructions do affect the quality of the narrative produced by healthy older adults. The instructions to provide a story with a beginning, middle, and end may have acted as a scaffold for participants; cueing participants to provide the temporal–causal relationships depicted. Therefore, to better evaluate discourse production abilities in clinical populations, care should be taken in the task instructions provided.

Dynamics of the attentional control of word retrieval: Analyses of response time distributions.

Since W. Wundt (1904) and H. J. Watt (1906), researchers have found no agreement on how goals direct word retrieval. A prevailing associative account (E. K. Miller & J. D. Cohen, 2001) holds that goals bias association strength, which determines retrieval latency and whether irrelevant words interfere. A symbolic account (A. Roelofs, 2003) holds that goals enable retrieval rules and predicts no strict dependence of interference on latency. Here, 3 chronometric experiments in which the role of relative retrieval latency was investigated through distributional analyses, following Watt, are reported. Participants verbally categorized picture-word pairs that were semantically related or unrelated, or they categorized single pictures or words. The pairs yielded semantic latency effects in both word and picture categorizing, although single words were categorized slower than single pictures. Semantic effects occurred in word categorizing even when postexposure of the pictures compensated for the difference in categorizing latency. Vincentile and ex-Gaussian analyses revealed that the semantic effects occurred throughout the latency distributions, excluding goal neglect as the cause of the effects. The results were interpreted as most consistent with the symbolic account, which was corroborated by computer simulations.

Vision screening: a benchmarking audit

A benchmarking exercise earned out in 2006 round that despite the recommendations for an orthoptist-led vision screening service1–5 many primary care trusts were not providing comprehensive vision screen­ing (vision testing of every child of one age group). Where screening is carried out it is not always orthoptist-led and tests may be performed by health visitors, school nurses and school nurse assistants. Selective testing (testing a proportion of an age group using risk criteria) is being organised by health promotion groups and school health advisors rather than clinicians. The assessments vary from questions to identify children at risk6 to the recommended crowded logMAR letters test, but many children are being tested with single optotype pictures or letters. The exercise highlighted the inequal­ity of access to screening for children from neighbouring primary care trusts, and in London it was generally the most deprived areas with the greatest health needs which had the least provision.

Emotional stimuli and context moderate effects of nicotine on specific but not global affects.

The authors tested the hypothesis that the effects of nicotine on affect are moderated by the presence or absence of emotionally positive and negative stimuli and by attentional choice to avoid attending to emotionally negative stimuli. Thirty-two habitual smokers were assigned to tasks allowing attentional freedom to look back and forth at 2 simultaneously presented pictures, whereas another 32 habitual smokers viewed single pictures without attentional choice. Picture contents in both tasks were 1 of 4 combinations: emotionally negative + neutral, negative + positive, positive + neutral, or neutral + neutral. Participants wore a nicotine patch on 1 day and placebo patch on another day. Nicotine reduced anxiety most when negative pictures were presented in combination with neutral pictures, but it had no effect on anxiety when negative pictures were presented in combination with positive pictures and when negative pictures were not presented. In contrast, nicotine only reduced depressive affect when the participant had attentional choice between positive and negative pictures. Nicotine also enhanced positive affect and reduced negative affect as measured by the Positive and Negative Affect Schedule, but these effects were not moderated by task manipulations. Overall, the findings support the view that nicotine's ability to reduce specific negative affects is moderated by emotional context and attentional freedom. Nicotine tended to enhance eye-gaze orientation to emotional pictures versus neutral pictures in women, but it had no significant effect on eye-gaze in men.

Patterns of language improvement in adults with non‐chronic non‐fluent aphasia after specific therapies

Background: Methods for functional and linguistic analysis of discourse have been used for describing recovery from aphasia and examining relationships between patterns of recovery and specific therapeutic programmes. This approach, however, has mainly concerned therapeutic programmes for chronic aphasic symptoms (e.g., therapy for chronic agrammatism in non‐fluent aphasic subjects). Aims: The first aim of this study was to examine whether functional and linguistic analyses of discourse are suitable to describe aspects of language improvement in subjects recovering from non‐fluent aphasia in the first months post‐onset. A second objective was to assess the effectiveness of two therapy programmes for chronic aphasia in increasing informativeness and/or morpho‐syntactic organisation of connected speech. This was made by examining in‐depth the correspondence between each of the two therapy programmes and the results from functional and linguistic analysis of discourse at pre‐ and post‐therapy evaluation. Methods & Procedures: Three subjects with non‐fluent aphasia (12, 18, and 22 weeks post‐onset, respectively), whose speech was characterised by reduced information content and poor morpho‐syntactic organisation, received two consecutive therapy programmes, each consisting of 35 one‐hour sessions in seven weeks. The first programme consisted of stimulus–response exercises for producing well‐formed sentences (HELPSS, Helm‐Estabrooks, Fitzpatrick, & Barresi, 1981). This was followed by a functional treatment programme in PACE format (Carlomagno, Losanno, Emanuelli, & Razzano, 1991) intended to increase informativeness of communicative (verbal and non‐verbal) behaviour. At the three assessments (before and after HELPSS and after modified PACE) the three participants were asked to describe two cartoon stories and two single pictures. These connected speech samples underwent functional analysis (CIUs, Nicholas & Brookshire, 1993; Main Concept Analysis, Nicholas & Brookshire, 1995) and linguistic analysis (Marini, Caltagirone, Carlomagno, & Nocentini, 2005a; Marini, Boewe, Caltagirone, & Carlomagno, 2005b) in order to examine the pattern of language recovery. The three participants also received functional evaluation with the EFCP (Wirz, Skinner, & Dean, 1990) for assessing changes in language performance in communicative interaction. At the beginning and end of the therapy period, further evaluation was performed by means of standardised aphasia tests (AAT, Italian version, Luzzatti, Willems, & DeBleser, 1991; CADL, Italian version, Pizzamiglio et al., 1984). Outcomes & Results: Following the therapy programmes, a few changes were observed on standard aphasia tests. However, the informativeness of the speech samples by the three subjects increased. This corresponded to better rating of their language in the EFCP interview. In two subjects, the linguistic analysis of connected speech samples failed to show consistent syntactic organisation at the post‐therapy evaluation and differences between effects of the two programmes were marginal. In the third, the pattern of recovery did not correspond closely to that predicted by the type of treatment, i.e., better syntactic organisation of speech output became evident only after the second therapy programme. Conclusions: It is suggested that discourse analysis methods are useful for studying functional and linguistic aspects of recovery in subjects with non‐fluent aphasia in the early post‐onset period. Furthermore, in this period, specific therapy for chronic agrammatic symptoms may not reduce them. Nonetheless, this therapeutic approach plays a role in improving language informativeness particularly when combined with a functional approach.

Stabilization of solvent-impregnated resins (SIRs) by coating with water-soluble polymer and chemical cross-linking and its application in mercury removal

Stabilization of solvent impregnated resins was achieved by the formation of a surface coating with the absorptive layer of poly(vinyl alcohol) and cross-linking with the protective layer of vinyl sulphone (VS). Amberlite XAD-4 and vinyl sulphone proved to be effective matrix and cross-linking agents, respectively, in the preparation of a protective layer of SIRs containing Cyanex 923 as extractant. The stabilized SIRs were characterized by the amount of vinyl sulphone contributing to the N and S content in the stabilized resin as well as to its operational stability. Optical and single electron microscope pictures were used to examine the appearance and the morphology, respectively, of the external protective barrier of SIR. Batch and column mode of sorption/elution studies for the removal of mercury from aqueous solution at pH 4 were carried out with Cyanex 923 containing SIR coated with PVA cross-linked with VS. Stabilized SIR was found to be effective for the mercury removal and showed great stability during the batch recycle runs. Elution of mercury from SIR was quantitatively achieved with 3M HNO3. Kinetic and column performances were influenced by the degree of cross-linking of resin coating. Chemical stability and sorption capacity of stabilized SIR remained almost constant after several recycle runs whilst uncoated SIRs lose extractant with time as confirmed by efficiency studies.

Electronic structure and aspects of unconventional superconductivity in Na xCoO2.yH2O

We examine the electronic structure of NaxCoO2.yH2O within the local density approximation. The parametrization of the band which forms the largest hole-Fermi surface centered at G shows significant deviations from what is frequently assumed in recent sophisticated theoretical studies. In particular, the commonly used nearest neighbor approaches in the framework of single band pictures are found to be unrealistic. The special role of H2O in screening the disorder in the charge reservoir is briefly discussed and compared with the case of Y1-xCaxCu3O6+d.

Relationship between discourse and Western Aphasia Battery performance in African Americans with aphasia

Background: There is a need for discourse research with African Americans who have aphasia, highlighted by ethnic group differences in stroke prevalence, and potential ethnic group differences in dialect. Identification of ethnic dialect is critical to differentiate communication changes associated with pathology from normal communicative differences associated with ethnicity. Also, preliminary research on adults with aphasia indicates an uncertain relationship between discourse performance and standardised test performance. Aims: This study was designed to assess: (1) the relationship between performance on a standardised language measure and discourse performance, and (2) the use of ethnic dialect and discourse features, in the narrative productions of African-American adults with moderate aphasia on a variety of discourse tasks. Methods & Procedures: We investigated the discourse of 12 African Americans with scores in the moderate severity range on the Western Aphasia Battery, Aphasia Quotient (WAB-AQ). Each subject produced a fable retell, a story derived from a picture sequence, two stories derived from single pictures, and a topic-elicited personal narrative of a frightening experience. Analysis consisted of ratings of discourse quality (coherence, reference, and emplotment); a measure of discourse quantity (number of propositions); and a tally of the presence or absence of ethnic dialect and discourse features. Outcomes & Results: The correlation between WAB-AQ and discourse quality was statistically significant on the picture sequence task and one single-picture task, but not on the other discourse tasks. There was a significant relationship between WAB-AQ and overall quality ratings of coherence, reference, and emplotment. The correlation between WAB-AQ and discourse quantity was not significant for any task, and discourse quality was not significantly correlated with discourse quantity. Ethnic features appeared most often on one single-picture task and the personal narrative. No ethnic dialect features occurred on the fable retell. Conclusions : These findings suggest the need to supplement standardised assessment of aphasia with assessment of discourse performance, using less structured discourse tasks, such as a personal narrative task. Less structured discourse tasks may also be optimal for eliciting natural ethnic patterns of communication. The lack of relationship between narrative quantity and narrative quality may not generalise to individuals with aphasia that is severe or mild. This study contributes towards development of a discourse assessment tool for culturally and linguistically diverse populations that may supplement information provided by standardised testing.

Discourse elicitation with pictorial stimuli in African Americans and Caucasians with and without aphasia

Background: Pictorial stimuli are a traditional means of discourse elicitation for individuals with aphasia. The discourse genre produced in response to pictures may be affected by the presence of aphasia, the nature of the stimulus, or both. Ethnicity may also influence discourse responses, an issue critical for effective differentiation between communication changes associated with pathology and normal differences associated with ethnicity. There is a need for discourse research with African Americans who have aphasia, highlighted by ethnic group differences in stroke prevalence, and potential ethnic group differences in dialect. Aims: This study was designed to address whether the quantity and quality of discourse produced in response to pictorial stimuli differed between African Americans and Caucasians with and without aphasia. Methods & Procedures: We investigated the discourse of 33 African Americans with aphasia, 30 African American non-brain-injured controls, 29 Caucasians with aphasia, and 32 Caucasian non-brain-injured controls in their responses to two single pictures and one picture sequence. For the individuals with aphasia, aphasia severity level ranged from mild to moderate. There were no significant group differences for age or education. Participants were asked to “tell a story” and responses were produced after the stimulus was removed. Analyses included length of response (in propositions), discourse genre of response (narrative versus descriptive), occurrence of ethnic dialect, and thematic content. Outcomes & Results: In both ethnic groups, individuals with aphasia produced less language on the most complex stimulus. Single pictures elicited more descriptive discourse, and the picture sequence more narratives, for all groups. Features of African American dialect were observed in responses of both African American non-brain-injured controls and African Americans with aphasia on all stimuli, especially in narrative genre responses. Thematic content was similar across groups.

Brain activity and cognitive status in pediatric patients: development of a clinical assessment protocol.

The purpose of this study was to test the validity of a new computerized task to assess children's cognitive problem-solving skills using the brain event-related potentials. This event-related potential-computerized cognitive problem-solving task does not require a child to give a verbal or motor (ie, pointing) response. The event-related potential waveforms were recorded from 20 typically developing children. Two nonverbal, problem-solving tasks (tasks 1 and 2) were developed for each of two age groups (5 and 6 years). For each task, single pictures, taken from an existing standardized test of nonverbal problem solving, were individually and sequentially presented on a computer screen. One of the seven pictures was classified as incongruent or outside category; it did not belong with the other pictures. As predicted, the event-related potential amplitudes were significantly larger to the outside- versus within-category pictures. This effect was found for tasks 1 and 2 for the 5- and 6-year-old children. Children as young as 5 years of age reliably exhibit brain activity, which can be used to infer cognitive problem-solving skill. This assessment paradigm may eventually serve as a clinically useful adjunct to a thorough neurologic and neurodevelopmental assessment of selected pediatric populations, such as those presenting with moderate-severe cerebral palsy whose expressive language and motor skills are notably impaired.

Mental spatial transformations of objects and perspective

This study sought evidence for the independence of two classes of mental spatial transformation: object-based spatial transformations and egocentric perspective transformations. Two tasks were designed to selectively elicit these two transformations using the same materials, participants, and task parameters: one required same-different judgments about pairs of pictures, while the other required left-right judgments about single pictures. For pictures of human bodies, the two tasks showed strikingly different patterns of response time as a function of stimulus orientation. Moreover, across individuals, the two tasks had different relationships to psychometric tests of spatial ability. The chronometric and individual difference data converge with neuropsychological and neuroimaging data in suggesting that different mental spatial transformations are performed by dissociable neural systems.

La complexité comme paradigme pour concevoir une régulation juridique adéquate

Complexity as a Paradigm for Drawing a « Satisficing » Legal Regulation. A morphogenetic study of the co-evolution of societies and their legal Systems requires the use of new paradigms, going beyond a strictly positivist framework. A non-paradoxical explanation of a movement with a succession of single pictures is impossible, except if complex and constructivist paradigms are used. Well-defined concepts can give a « satisficing » representation of reality. This makes it possible to suggest a model of the emergence of a legally regulated social System. This type of projective modelling, combining deconstruction and simulation, can be useful in a legistic process, by allowing the evaluation of the foreseeable and non foreseeable consequences of norms.

Brain activity and language assessment using event‐related potentials: development of a clinical protocol

To test the validity of a new computerized task to assess children's receptive vocabulary, event‐related potentials (ERPs) were recorded from 56 typically developing children ranging in age from 5 to 12 years. This ERP‐computerized vocabulary task does not require a child to give a verbal or motor (i.e. pointing) response. Single pictures, from an existing standardized test of receptive vocabulary, were presented on a computer screen and simultaneously named either correctly (congruent) or incorrectly (incongruent) via a computer. As predicted, the N400 amplitude was found to be significantly higher to the incongruent picture‐word pair (i.e. the child knew it was an incorrect pairing) than to the congruent picture‐word pair (i.e. the child knew it was a correct pairing). This effect was found for each of the four age groups (5 to 6 years, 7 to 8 years, 9 to 10 years, 11 to 12 years). This task accurately estimated current receptive vocabulary in typically developing children. Although still in the development stage, it may eventually serve as an adjunct to a thorough neurological and neurodevelopmental assessment of some children presenting with moderate to severe cerebral palsy.

Brain activity and language assessment using event-related potentials: development of a clinical protocol.

To test the validity of a new computerized task to assess children's receptive vocabulary, event-related potentials (ERPs) were recorded from 56 typically developing children ranging in age from 5 to 12 years. This ERP-computerized vocabulary task does not require a child to give a verbal or motor (i.e. pointing) response. Single pictures, from an existing standardized test of receptive vocabulary, were presented on a computer screen and simultaneously named either correctly (congruent) or incorrectly (incongruent) via a computer. As predicted, the N400 amplitude was found to be significantly higher to the incongruent picture-word pair (i.e. the child knew it was an incorrect pairing) than to the congruent picture-word pair (i.e. the child knew it was a correct pairing). This effect was found for each of the four age groups (5 to 6 years, 7 to 8 years, 9 to 10 years, 11 to 12 years). This task accurately estimated current receptive vocabulary in typically developing children. Although still in the development stage, it may eventually serve as an adjunct to a thorough neurological and neurodevelopmental assessment of some children presenting with moderate to severe cerebral palsy.

The temporomandibular joint in video motion — noninvasive image techniques to present the functional anatomy

The presentation of the functional anatomy of the temporomandibular joint (TMJ) is involved with difficulties if dynamic aspects are to be of prime interest, and it should be demonstrated with the highest resolution. Usually noninvasive techniques like MRI and sonography are available for presenting functionality of the temporomandibular joint in video motion. Such images reflect the functional anatomy much better than single pictures of figures could do. In combination with computer aided records of the condyle movements the video motion of MR and sonographical images represent tools for better understanding the relationships between functional or dysfunctional patterns and the morphological or dysmorphological shape and structure of the temporomandibular joint. The possibilities of such tools will be explained and discussed in detail relating, in addition, to loading effects caused by transmitted occlusal pressure onto the joint compartments. If pressure occurs the condyle slides mainly more or less retrocranially whereas the articular disc takes up a more displaced position and a deformed shape. In a few extreme cases the disc prolapses out of the joint space. These video pictures offer new aspects for the diagnosis of the disc-condyle stability and can also be used for explicit educational programs on the complex dysfunction-dysmorphology-relationship of temporomandibular diseases.

Weighted finite automata for video compression

Weighted finite automata (WFA) exploit self-similarities within single pictures and also sequences of pictures to remove spatial and temporal redundancies. Their implementation then combines techniques from hierarchical methods related to quadtrees and from vector quantization to achieve performance results for low bit rates which can be put on a par with state-of-the-art codecs like embedded zero-tree wavelet coding. Due to their simple mathematical structure, WFA provide an ideal platform for efficient hybrid compression methods. Therefore, WFA were chosen as a starting point for a fractal-like video compression integrating a hierarchical motion compensation as well as an option to vary the compression quality between "centers of interest" and "background" in a flexible manner.