In the human electroencephalogram (EEG), induced oscillatory responses in various frequency bands are regarded as valuable indices to examine the neural mechanisms underlying human memory. While the ...advent of virtual reality (VR) drives the investigation of mnemonic processing under more lifelike settings, the joint application of VR and EEG methods is still in its infancy (e.g., due to technical limitations impeding the signal acquisition). The objective of the present EEG study was twofold. First, we examined whether the investigation of induced oscillations under VR conditions yields equivalent results compared to standard paradigms. Second, we aimed at obtaining further insights into basic memory-related brain mechanisms in VR. To these ends, we relied on a standard implicit memory design, namely repetition priming, for which the to-be-expected effects are well-documented for conventional studies. Congruently, we replicated a suppression of the evoked potential after stimulus onset. Regarding the induced responses, we observed a modulation of induced alphaband in response to a repeated stimulus. Importantly, our results revealed a repetition-related suppression of the high-frequency induced gammaband response (>30 Hz), indicating the sharpening of a cortical object representation fostering behavioral priming effects. Noteworthy, the analysis of the induced gammaband responses required a number of measures to minimize the influence of external and internal sources of artefacts (i.e., the electrical shielding of the technical equipment and the control for miniature eye movements). In conclusion, joint VR–EEG studies with a particular focus on induced oscillatory responses offer a promising advanced understanding of mnemonic processing under lifelike conditions.
Background
Non‐word repetition (NWR) tests are an important way speech and language therapists (SaLTs) assess language development. NWR tests are often scored whilst participants make their responses ...(i.e., in real time) in clinical and research reports (documented here via a secondary analysis of a published systematic review).
Aims
The main aim was to determine the extent to which real‐time coding of NWR stimuli at the whole‐item level (as correct/incorrect) was predicted by models that had varying levels of detail provided from phonemic transcriptions using several linear mixed method (LMM) models.
Methods & Procedures
Live scores and recordings of responses on the universal non‐word repetition (UNWR) test were available for 146 children aged between 3 and 6 years where the sample included all children starting in five UK schools in one year or two consecutive years. Transcriptions were made of responses to two‐syllable NWR stimuli for all children and these were checked for reliability within and between transcribers. Signal detection analysis showed that consonants were missed when judgments were made live. Statistical comparisons of the discrepancies between target stimuli and transcriptions of children's responses were then made and these were regressed against live score accuracy. Six LMM models (three normalized: 1a, 2a, 3a; and three non‐normalized: 1b, 2b, 3b) were examined to identify which model(s) best captured the data variance. Errors on consonants for live scores were determined by comparison with the transcriptions in the following ways (the dependent variables for each pair of models): (1) consonants alone; (2) substitutions, deletions and insertions of consonants identified after automatic alignment of live and transcribed materials; and (3) as with (2) but where substitutions were coded further as place, manner and voicing errors.
Outcomes & Results
The normalized model that coded consonants in non‐words as ‘incorrect’ at the level of substitutions, deletions and insertions (2b) provided the best fit to the real‐time coding responses in terms of marginal R2, Akaike's information criterion (AIC) and Bayesian information criterion (BIC) statistics.
Conclusions & Implications
Errors that occur on consonants when non‐word stimuli are scored in real time are characterized solely by the substitution, deletion and insertion measure. It is important to know that such errors arise when real‐time judgments are made because NWR tasks are used to assess and diagnose several cognitive–linguistic impairments. One broader implication of the results is that future work could automate the analysis procedures to provide the required information objectively and quickly without having to transcribe data.
WHAT THIS PAPER ADDS
What is already known on this subject
Children and patients with a wide range of cognitive and language difficulties are less accurate relative to controls when they attempt to repeat non‐words. Responses to non‐words are often scored as correct or incorrect at the time the test is conducted. Limited assessments of this scoring procedure have been conducted to date.
What this study adds to the existing knowledge
Live NWR scores made by 146 children were available and the accuracy of these judgements was assessed here against ones based on phonemic transcriptions. Signal detection analyses showed that live scoring missed consonant errors in children's responses. Further analyses, using linear mixed effect models, showed that live judgments led to consonant substitution, deletion and insertion errors.
What are the practical and clinical implications of this work?
Improved and practicable NWR scoring procedures are required to provide SaLTs with better indications about children's language development (typical and atypical) and for clinical assessments of older people. The procedures currently used miss substitutions, deletions and insertions. Hence, procedures are required that provide the information currently only available when materials are transcribed manually. The possibility of training automatic speech recognizers to provide this level of detail is raised.
The objective of this study was to determine the appropriate number of replicates to identify significant differences in carcass and cut yields in broiler chickens. At 42 d of age, a total of 480 ...broiler chickens were selected, weighed, and processed to obtain the hot carcass yield. Subsequently, after cooling, the cold carcass yield was determined. The cold carcass was dismembered into boneless and skinless breast, tenders, legs, and whole wings, which were individually weighed to obtain the cuts yield. The collected data underwent normality analysis and subsequent determination of descriptive statistics, as well as analysis of variance, in both cases to determine mean values, standard deviation, and coefficient of variation (CV). The required number of replicates to detect differences between means for different magnitudes was determined. The CVs obtained were stable, with the highest CV observed for tenders’ yield (11.34%) and the lowest for the hot carcass (2.35%). To achieve significant differences in both, cold and hot carcass, a minimum of 8 replicates is needed for 5% differences in 97% of experiments. For breast fillet characteristics, 10 replicates are required to detect a 10% difference in 99% of experiments. Due to higher variation, tenders yield necessitates at least 10 replicates to detect a 20% difference in 90% of cases. For wing yield, 8 replicates suffice for 94% accuracy when differences exceed 15%. Lastly, 10 replicates enable detection of 7.5% differences in leg variables in 95% of experiments. Effective experimental planning, based on the statistical power of the test, is essential for determining the requisite number of replicates. Researchers must prioritize the specific carcass characteristic relevant to their study and design the number of replicates, accordingly, ensuring more reliable and realistic results.
ABSTRACTLates, AD, Greer, BK, Wagle, JP, and Taber, CB. Accentuated eccentric loading and cluster set configurations in the bench press. J Strength Cond Res XX(X)000–000, 2020—This study was designed ...to examine the kinetic and kinematic differences between an Accentuated eccentric loading (AEL), traditional loading, and cluster sets in trained male subjects (age23.7 ± 4.0 years, height176.4 ± 2.8 cm, mass93.6 ± 7.0 kg) with lifting experience (training age7.2 ± 2.4 years, 1-repetition maximum (1RM) bench press125.0 ± 14.8 kg, relative strength ratio1.3 ± 0.1) in the bench press. Subjects reported for a total of 5 sessions which consisted of a 1RM testing session and 4 experimental trials. The 4 experimental conditions consisted of a traditional load (TRAD), traditional load with inter-repetition rest (TRDC), accentuated eccentric loading with inter-repetition rest (AELC), and Accentuated eccentric loading for the first repetition only (AEL1). Concentric load was 80% of subjectsʼ 1RM for all conditions. An eccentric overload of 105% of 1RM was applied using weight-releasing hooks during the AEL conditions. TRDC demonstrated superior concentric outputs for mean velocity and mean power compared with TRAD, AELC, and AEL1 (p < 0.001). In addition, AEL1 produced significantly greater effects for rate of force development compared with TRDC (p < 0.001). These findings suggest that inter-repetition rest had an influence on concentric performance, specifically mean power and mean velocity, and may be favorable when using higher loads and when sustained power outputs are desired. In addition, AEL1 may provide a unique eccentric stimulus that alters loading parameters compared with traditional loading conditions.
Decades of research in attention have shown that salient distractors (e.g., a color singleton) tend to capture attention. However, in most studies, singleton distractors are just as likely to be ...present as absent. We therefore have little knowledge of how probabilistic expectations of the salient distractor's occurrence and features affect suppression. In three experiments, we explored this question by manipulating the frequency of a singleton distractor and the variability of its color within a search display. We found that increased expectations regarding the occurrence of the singleton distractor eliminated the singleton response time cost and reduced the number of first saccades to the singleton. In contrast, expectations regarding variability in the singleton color did not affect singleton capture. This was surprising and suggests the ability to suppress second-order salience over and above that of first-order features. We next inserted the probe display that included a to-be-reported letter inside each shape between search trials to measure if attention went to multiple objects. The letter in the singleton location was reported less often in the high-frequency condition, suggesting proactive suppression of expected singleton. Additionally, we found that trial-to-trial repetitions of a singleton (irrespective of its color and location) facilitated performance (i.e., singleton repetition priming), but repetitions of its specific color or location did not. Together our findings demonstrate that attentional capture by a color singleton distractor is attenuated by probabilistic expectations of its occurrence, but not of its color and location.
Public Significance Statement
The mechanisms of target selection have been well-studied whereas those of distractor suppression are less well understood. One of reasons may be that there is still disagreement about whether salient distractors necessarily capture attention, which has led to a rich debate regarding the automaticity of attentional capture by stimulus saliency. However, these previous studies have primarily pitted attentional goals based on the target search strategy against perceptual saliency that cannot be predicted. We therefore have little knowledge of how probabilistic expectations affect attentional capture by a singleton distractor, yet performance in real-world environments rely heavily on expectations. We address this question in a series of three studies. Our results demonstrate that increased expectations regarding the occurrence of the singleton distractor eliminated attentional capture (indexed by search response time and first saccades). In contrast, expectations regarding singleton feature (i.e., color) did not affect singleton capture, even when there were 192 different singleton colors used. These results suggest that attentional capture by a singleton distractor is attenuated by probabilistic expectations of its occurrence, but not its specific color and location. This indicates that distractor suppression, like target selection, can operate at different levels of stimulus processing and be flexibly attuned to the type of information expected within the current environment.
Petawatt lasers are now available in a number of facilities around the world and are becoming a very useful tool in physics and engineering. Some of such lasers are able -or will be able soon- to ...fire at high repetition rates (one shot per second or more). Experiments at such repetition rates have certain peculiarities that are to be briefly exposed here, based on the author’s experience with the Salamanca VEGA-3 laser. VEGA-3 is a 30 fs PW laser, firing one shot per second.
Background
Previous research demonstrates that repetition tasks are valuable tools for diagnosing specific language impairment (SLI) in monolingual children in English and a variety of other ...languages, with non‐word repetition (NWR) and sentence repetition (SRep) yielding high levels of sensitivity and specificity. Yet, only a few studies have addressed the diagnostic accuracy of repetition tasks in bilingual children, and most available research focuses on English–Spanish sequential bilinguals.
Aims
To evaluate the efficacy of three repetition tasks (forward digit span (FWD), NWR and SRep) in order to distinguish mono‐ and bilingual children with and without SLI in Russian and Hebrew.
Methods & Procedures
A total of 230 mono‐ and bilingual children aged 5;5–6;8 participated in the study: 144 bilingual Russian–Hebrew‐speaking children (27 with SLI); and 52 monolingual Hebrew‐speaking children (14 with SLI) and 34 monolingual Russian‐speaking children (14 with SLI). Parallel repetition tasks were designed in both Russian and Hebrew. Bilingual children were tested in both languages.
Outcomes & Results
The findings confirmed that NWR and SRep are valuable tools in distinguishing monolingual children with and without SLI in Russian and Hebrew, while the results for FWD were mixed. Yet, testing of bilingual children with the same tools using monolingual cut‐off points resulted in inadequate diagnostic accuracy. We demonstrate, however, that the use of bilingual cut‐off points yielded acceptable levels of diagnostic accuracy. The combination of SRep tasks in L1/Russian and L2/Hebrew yielded the highest overall accuracy (i.e., 94%), but even SRep alone in L2/Hebrew showed excellent levels of sensitivity (i.e., 100%) and specificity (i.e., 89%), reaching 91% of total diagnostic accuracy.
Conclusions & Implications
The results are very promising for identifying SLI in bilingual children and for showing that testing in the majority language with bilingual cut‐off points can provide an accurate classification.
Locking of longitudinal modes in laser cavities is the common path to generate ultrashort pulses. In traditional multi-wavelength mode-locked lasers, the group velocities rely on lasing wavelengths ...due to the chromatic dispersion, yielding multiple trains of independently evolved pulses. Here, we show that mode-locked solitons at different wavelengths can be synchronized inside the cavity by engineering the intracavity group delay with a programmable pulse shaper. Frequency-resolved measurements fully retrieve the fine temporal structure of pulses, validating the direct generation of synchronized ultrafast lasers from two to five wavelengths with sub-pulse repetition-rate up to ~1.26 THz. Simulation results well reproduce and interpret the key experimental phenomena, and indicate that the saturable absorption effect automatically synchronize multi-wavelength solitons in despite of the small residual group delay difference. These results demonstrate an effective approach to create synchronized complex-structure solitons, and offer an effective platform to study the evolution dynamics of nonlinear wavepackets.
High-resolution wide-swath synthetic aperture radar (HRWS-SAR) imaging is highly desirable since it allows one to produce high-resolution SAR images of large areas during a short visit time. In this ...article, staggered coprime pulse repetition frequencies synthetic aperture radar (SCopSAR) is proposed. It divides the time during which a scatterer is illuminated by the antenna beam pattern into two halves where, in each half, pulses are transmitted at the rate of one of two sub-Nyquist pulse repetition frequencies (PRFs). Such PRFs are related to the Nyquist PRF using two coprime subsampling factors. This allows extending the maximum range swath width that can be imaged by a number of times that equals the smaller subsampling factor at the expense of a reduction in the azimuth resolution by half. It further allows for a reduction in the amount of data to be stored and communicated. SCopSAR is an imaging modality suitable for scenes that contain a small number of bright scatterers over a dark background which, for instance, is the case when imaging ships in a calm sea background. Compared with the techniques recently proposed in the literature, SCopSAR simplifies the radar requirements since it uses only one carrier frequency, one waveform, and one channel. Simulations and real ERS-2 satellite raw data are used to validate the theoretical findings presented in this article.
PDF
