Implicit Task Research Articles

Implicit cross-situational word learning in children with and without developmental language disorder and its relation to lexical-semantic knowledge

IntroductionResearch indicates that statistical learning plays a role in word learning by enabling the learner to track the co-occurrences between words and their visual referents, a process that is named cross-situational word learning. Word learning is problematic for children with developmental language disorder (DLD), and a deficit in statistical learning has been suggested to contribute to the language difficulties in these children. Therefore, we investigate whether children with DLD have more difficulty than TD children with learning novel word–referent pairs based on cross-situational statistics in an implicit task, and whether this ability is related to their lexical-semantic skills. Moreover, we look at the role of variability of the learning environment.MethodsIn our implicit cross-situational word learning task, each trial in the exposure phase was in itself ambiguous: two pictures of unknown objects were shown at the same time and two novel words were played consecutively, without indicating which word referred to which object. However, as every word occurred with its correct referent consistently, the children could learn the word–referent pairs across trials. The children were not explicitly instructed to learn the names of new objects. As an on-line measure of learning, eye-movements were recorded during the exposure phase. After exposure, word–referent knowledge was also tested using multiple choice questions. Several measures of lexical-semantic knowledge were administered to the children with DLD, as well as tasks measuring non-verbal intelligence and phonological processing. Contextual variability (the number of different distractors with which a particular word–referent pair occurs across trials) was manipulated between subjects by constructing two types of exposure conditions: low contextual diversity vs. high contextual diversity.ResultsBoth groups of children performed significantly above chance level on the test phase, but the TD children significantly outperformed the children with DLD. We found no significant effect of contextual diversity. The eye-tracking data revealed some evidence of on-line learning, but no differences between groups. Finally, the regression analyses did not reveal any significant predictors of off-line or on-line cross-situational word learning ability.DiscussionOur results indicate that although children with DLD are able to learn word-referent pairs in an implicit task, they have more difficulty than TD children. Possibly they need more input to achieve the same level.

Neurocognitive Dynamics of Prosodic Salience over Semantics during Explicit and Implicit Processing of Basic Emotions in Spoken Words.

How language mediates emotional perception and experience is poorly understood. The present event-related potential (ERP) study examined the explicit and implicit processing of emotional speech to differentiate the relative influences of communication channel, emotion category and task type in the prosodic salience effect. Thirty participants (15 women) were presented with spoken words denoting happiness, sadness and neutrality in either the prosodic or semantic channel. They were asked to judge the emotional content (explicit task) and speakers' gender (implicit task) of the stimuli. Results indicated that emotional prosody (relative to semantics) triggered larger N100, P200 and N400 amplitudes with greater delta, theta and alpha inter-trial phase coherence (ITPC) and event-related spectral perturbation (ERSP) values in the corresponding early time windows, and continued to produce larger LPC amplitudes and faster responses during late stages of higher-order cognitive processing. The relative salience of prosodic and semantics was modulated by emotion and task, though such modulatory effects varied across different processing stages. The prosodic salience effect was reduced for sadness processing and in the implicit task during early auditory processing and decision-making but reduced for happiness processing in the explicit task during conscious emotion processing. Additionally, across-trial synchronization of delta, theta and alpha bands predicted the ERP components with higher ITPC and ERSP values significantly associated with stronger N100, P200, N400 and LPC enhancement. These findings reveal the neurocognitive dynamics of emotional speech processing with prosodic salience tied to stage-dependent emotion- and task-specific effects, which can reveal insights into understanding language and emotion processing from cross-linguistic/cultural and clinical perspectives.

A Topic-Chain Approach to Teaching English-Chinese Textual Translation Strategies

This paper investigates the effectiveness of three approaches to teaching English-Chinese textual translation strategies to intermediate level EFL (English as a Foreign Language) learners. The learners were randomly assigned to one of three groups and taught using different methods, each with its own chain: Explicit-Method-Chain (EMC), Explicit-Task Method Chain (ETMC), or Implicit Task Method Chain (ITMC). This is a mixed methods study that employed quantitative and qualitative data in the formative stage, followed by a comparative analysis. The results show that all strategies are effective in teaching translational skills to intermediate level EFL learners but explicit task method chains are more effective than explicit method chains.

HD-tDCS of primary and higher-order motor cortex affects action word processing.

The contribution of action-perception systems of the brain to lexical semantics remains controversial. Here, we used high-definition transcranial direct current stimulation (HD-tDCS) in healthy adults to examine the role of primary (left hand motor area; HMA) and higher-order (left anterior inferior parietal lobe; aIPL) action areas in action-related word processing (action verbs and manipulable nouns) compared to non-action-related control words (non-action verbs and non-manipulable nouns). We investigated stimulation-related effects at three levels of semantic processing: subliminal, implicit, and explicit. Broadly, we found that stimulation of HMA and aIPL resulted in relative facilitation of action-related language processing compared to non-action. HMA stimulation facilitated action verb processing in subliminal and implicit task contexts, suggesting that HMA helps represent action verbs even in semantically shallow tasks. HMA stimulation also facilitated manipulable noun comprehension in an explicit semantic task, suggesting that HMA contributes to manipulable noun comprehension when semantic demands are high. aIPL stimulation facilitated both manipulable noun and action verb processing during an implicit task. We suggest that both HMA and aIPL play a functional role in action semantics. HMA plays a general role in the semantics of actions and manipulable objects, while aIPL is important only when visuo-motor coordination is required for the action.

No statistical learning advantage in children over adults: Evidence from behaviour and neural entrainment

Explicit recognition measures of statistical learning (SL) suggest that children and adults have similar linguistic SL abilities. However, explicit tasks recruit additional cognitive processes that are not directly relevant for SL and may thus underestimate children’s true SL capacities. In contrast, implicit tasks and neural measures of SL should be less influenced by explicit, higher-level cognitive abilities and thus may be better suited to capturing developmental differences in SL. Here, we assessed SL to six minutes of an artificial language in English-speaking children (n = 56, 24 females, M = 9.98 years) and adults (n = 44; 31 females, M = 22.97 years), using explicit and implicit behavioural measures and an EEG measure of neural entrainment. With few exceptions, children and adults showed largely similar performance on the behavioural explicit and implicit tasks, replicating prior work. Children and adults also demonstrated robust neural entrainment to both words and syllables, with a similar time course of word-level entrainment, reflecting learning of the hidden word structure. These results demonstrate that children and adults have similar linguistic SL abilities, even when learning is assessed through implicit performance-based and neural measures.

Explicit and Implicit Emotion Processing in the Cerebellum: A Meta-analysis and Systematic Review.

The cerebellum's role in affective processing is increasingly recognized in the literature, but remains poorly understood, despite abundant clinical evidence for affective disruptions following cerebellar damage. To improve the characterization of emotion processing and investigate how attention allocation impacts this processing, we conducted a meta-analysis on task activation foci using GingerALE software. Eighty human neuroimaging studies of emotion including 2761 participants identified through Web of Science and ProQuest databases were analyzed collectively and then divided into two categories based on the focus of attention during the task: explicit or implicit emotion processing. The results examining the explicit emotion tasks identified clusters within the posterior cerebellar hemispheres (bilateral lobule VI/Crus I/II), the vermis, and left lobule V/VI that were likely to be activated across studies, while implicit tasks activated clusters including bilateral lobules VI/Crus I/II, right Crus II/lobule VIII, anterior lobule VI, and lobules I-IV/V. A direct comparison between these categories revealed five overlapping clusters in right lobules VI/Crus I/Crus II and left lobules V/VI/Crus I of the cerebellum common to both the explicit and implicit task contrasts. There were also three clusters activated significantly more for explicit emotion tasks compared to implicit tasks (right lobule VI, left lobule VI/vermis), and one cluster activated more for implicit than explicit tasks (left lobule VI). These findings support previous studies indicating affective processing activates both the lateral hemispheric lobules and the vermis of the cerebellum. The common and distinct activation of posterior cerebellar regions by tasks with explicit and implicit attention demonstrates the supportive role of this structure in recognizing, appraising, and reacting to emotional stimuli.

Test-retest reliability of a smartphone-based approach-avoidance task: Effects of retest period, stimulus type, and demographics.

The approach-avoidance task (AAT) is an implicit task that measures people’s behavioral tendencies to approach or avoid stimuli in the environment. In recent years, it has been used successfully to help explain a variety of health problems (e.g., addictions and phobias). Unfortunately, more recent AAT studies have failed to replicate earlier promising findings. One explanation for these replication failures could be that the AAT does not reliably measure approach-avoidance tendencies. Here, we first review existing literature on the reliability of various versions of the AAT. Next, we examine the AAT’s reliability in a large and diverse sample (N = 1077; 248 of whom completed all sessions). Using a smartphone-based, mobile AAT, we measured participants’ approach-avoidance tendencies eight times over a period of seven months (one measurement per month) in two distinct stimulus sets (happy/sad expressions and disgusting/neutral stimuli). The mobile AAT’s split-half reliability was adequate for face stimuli (r = .85), but low for disgust stimuli (r = .72). Its test–retest reliability based on a single measurement was poor for either stimulus set (all ICC1s < .3). Its test–retest reliability based on the average of all eight measurements was moderately good for face stimuli (ICCk = .73), but low for disgust stimuli (ICCk = .5). Results suggest that single-measurement AATs could be influenced by unexplained temporal fluctuations of approach-avoidance tendencies. These fluctuations could be examined in future studies. Until then, this work suggests that future research using the AAT should rely on multiple rather than single measurements.

Bodily self-recognition in patients with pathological embodiment.

The ability to discriminate between one's own and others' body parts can be lost after brain damage, as in patients who misidentify someone else's hand as their own (pathological embodiment). Surprisingly, these patients do not use visual information to discriminate between the own and the alien hand. We asked whether this impaired visual discrimination emerges only in the ecological evaluation when the pathological embodiment is triggered by the physical alien hand (the examiner's one) or whether it emerges also when hand images are displayed on a screen. Forty right brain‐damaged patients, with (E+ = 20) and without (E− = 20) pathological embodiment, and 24 healthy controls underwent two tasks in which stimuli depicting self and other hands was adopted. In the Implicit task, where participants judged which of two images matched a central target, the self‐advantage (better performance with Self than Other stimuli) selectively emerges in controls, but not in patients. Moreover, E+ patients show a significantly lower performance with respect to both controls and E− patients, whereas E− patients were comparable to controls. In the Explicit task, where participants judged which stimuli belonged to themselves, both E− and E+ patients performed worst when compared to controls, but only E+ patients hyper‐attributed others' hand to themselves (i.e., false alarms) as observed during the ecological evaluation. The VLSM revealed that SLF damage was significantly associated with the tendency of committing false alarm errors. We demonstrate that, in E+ patients, the ability to visually recognize the own body is lost, at both implicit and explicit level.

Neural correlates of embodied action language processing: a systematic review and meta-analytic study.

The neural correlates of action language processing are still debated within embodied cognition research and little is known about the flexible involvement of modality-specific pre-motor system and multimodal high-level temporo-parietal regions as a function of explicit and implicit tasks. A systematic review and the Activation likelihood estimation (ALE) meta-analyses on functional neuroimaging studies were performed to identify neural correlates of action language processing activated during explicit and implicit tasks. The contrast ALE meta-analysis revealed activation of modality-specific premotor area and inferior frontal areas during explicit action language tasks while a greater activation of posterior temporo-occipital areas emerged for implicit tasks. The conjunction analysis revealed overlap in the temporo-parietal multimodal high-level regions for both types of tasks. Functional specialization of the middle temporal gyrus was found where the more posterior-occipital part resulted activated during implicit action language tasks whereas the antero-lateral part was involved in explicit tasks. Our findings were discussed within a conceptual flexibility perspective about the involvement of both the modality-specific and multimodal brain system during action language processing depending on different types of tasks.

A dilemma of ground truth in noisy speech separation and an approach to lessen the impact of imperfect training data

As the performance of single-channel speech separation systems has improved, there has been a shift in the research community towards tackling more challenging conditions that are more representative of many real-world applications, including the addition of noise and reverberation. The need for ground truth in training state-of-the-art separation systems leads to a requirement of training on artificial mixtures, where single-speaker recordings are summed digitally. However, this leads to two separate approaches for creating noisy mixtures: one in which noise has been artificially added, maintaining perfect ground truth information, and one in which the noise is already present in the single-speaker recordings, allowing for in-domain training. In this work, we document a severe negative impact in both training and evaluation of models in the latter paradigm. We provide an explanation for this – the implicit task of separating noise – and propose an improved training objective that allows errors resulting from failing to separate noise to be minimized.

Trait Stereotypes of Scientists as Analytical and Cold Align With Perceptions of Men More Than Women on Both Implicit and Explicit Measures

Previous work using implicit tasks has demonstrated associations at a categorical level between men and science-related words (e.g., chemistry, physics, engineering). The current research explores trait attributes, examining the overlap in trait stereotypes of scientists with trait stereotypes of men and women, using both implicit and explicit stereotyping measures. Study 1 identified traits stereotypically associated with scientists along the analytic and cold dimensions, and counterstereotypic traits on unquestioning and warm dimensions. Study 2 demonstrated strong gender-scientist stereotypes on both explicit and implicit measures such that men were seen as more analytic and cold and less unquestioning and warm than women. Although robust effects were observed on both types of measures, their correlation was weak and nonsignificant. The misfit between trait perceptions of scientists and women, whether measured implicitly or explicitly, suggests trait stereotypes help maintain the gender imbalance in physical science fields.

No self-advantage in recognizing photographs of one’s own hand: experimental and meta-analytic evidence

Visually recognising one’s own body is important both for controlling movement and for one’s sense of self. Twenty previous studies asked healthy adults to make rapid recognition judgements about photographs of their own and other peoples’ hands. Some of these judgements involved explicit self-recognition: “Is this your hand or another person’s?” while others assessed self-recognition implicitly, comparing performance for self and other hands in tasks unrelated to self-other discrimination (e.g., left-versus-right; match-to-sample). We report five experiments with three groups of participants performing left-versus-right (Experiment 1) and self-versus-other discrimination tasks (Experiments 2 to 5). No evidence was found for better performance with self than with other stimuli, but some evidence was found for a self-disadvantage in the explicit task. Manipulating stimulus duration as a proxy for task difficulty revealed strong response biases in the explicit self-recognition task. Rather than discriminating between self and other stimuli, participants seem to treat self-other discrimination tasks as self-detection tasks, raising their criterion and consistently responding ‘not me’ when the task is difficult. A meta-analysis of 21 studies revealed no overall self-advantage, and suggested a publication bias for reports showing self-advantages in implicit tasks. Although this may appear counter-intuitive, we suggest that there may be no self-advantage in hand recognition.

The implicit effect of action mental simulation on action evaluation.

The main assumption underlying the present investigation is that action observation elicits a mandatory mental simulation representing the action forward in time. In Experiment 1, participants observed pairs of photos portraying the initial and the final still frames of an action video; then they observed a photo depicting the very same action but either forward or backward in time. Their task was to tell whether the action in the photo portrayed something happened before or after the action seen at encoding. In this explicit task, the evaluation was faster for forward photos than for backward photos. Crucially, the effect was replicated when instructions asked only to evaluate at test whether the photo depicted a scene congruent with the action seen at encoding (implicit task from two still frames, Experiment 2), and when at encoding, they were presented a single still frame and evaluated at test whether a photo depicted a scene congruent with the action seen at encoding (implicit task from single still frame; Experiment 3). Overall, the results speak in favour of a mandatory mechanism through which our brain simulates the action also in tasks that do not explicitly require action simulation.

Making peace with disliked others: the effects of a short loving-kindness meditation on implicit and explicit emotional evaluations

BackgroundThe main goal of the study was to investigate the effects of a short loving-kindness meditation (LKM) on explicit and implicit evaluations of oneself and disliked public persons. We expected a more positive explicit and implicit evaluation of oneself and a disliked public person after the LKM and a mood improvement.MethodsBefore and after the implementation of a short LKM vs. imagery task, mood, explicit and implicit evaluations were analyzed in 69 students.ResultsOur results demonstrated only a reduction in negative and positive mood in both groups and regarding the explicit and implicit tasks, only a significant main effect of picture and a trend for the time*group interaction for mood, implicit and explicit attitudes with medium effect-sizes.ConclusionsA possible influence of a short intervention on emotional evaluations should be treated with caution. The claim that a short loving-kindness meditation enhances social connectedness might awake false hopes. This study suggests being careful with the interpretation of single meditation effects and future studies should examine the effects of a long-lasting meditation training on explicit and implicit evaluations of the self and disliked politicians as well as the sustainability of those effects.

Interference-Aware Schedulability Analysis and Task Allocation for Multicore Hard Real-Time Systems

There has been a trend towards using multicore platforms for real-time embedded systems due to their high computing performance. In the scheduling of a multicore hard real-time system, there are interference delays due to contention of shared hardware resources. The main sources of interference are memory, cache memory, and the shared memory bus. These interferences are a great source of unpredictability and they are not always taken into account. Recent papers have proposed task models and schedulability algorithms to account for this interference delay. The aim of this paper is to provide a schedulability analysis for a task model that incorporates interference delay, for both fixed and dynamic priorities. We assume an implicit deadline task model. We rely on a task model where this interference is integrated in a general way, without depending on a specific type of hardware resource. There are similar approaches, but they consider fixed priorities. An allocation algorithm to minimise this interference (Imin) is also proposed and compared with existing allocators. The results show how Imin has the best rates in terms of percentages of schedulability and increased utilisation. In addition, Imin presents good results in terms of solution times.

Measuring Children’s Harmonic Knowledge with Implicit and Explicit Tests

We used implicit and explicit tasks to measure knowledge of Western harmony in musically trained and untrained Canadian children. Younger children were 6–7 years of age; older children were 10–11. On each trial, participants heard a sequence of five piano chords. The first four chords established a major-key context. The final chord was the standard, expected tonic of the context or one of two deviant endings: the highly unexpected flat supertonic or the moderately unexpected subdominant. In the implicit task, children identified the timbre of the final chord (guitar or piano) as quickly as possible. Response times were faster for the tonic ending than for either deviant ending, but the magnitude of the priming effect was similar for the two deviants, and the effect did not vary as a function of age or music training. In the explicit task, children rated how good each chord sequence sounded. Ratings were highest for sequences with the tonic ending, intermediate for the subdominant, and lowest for the flat supertonic. Moreover, the difference between the tonic and deviant sequences was larger for older children with music training. Thus, the explicit task provided a more nuanced picture of musical knowledge than did the implicit task.

Explicit vs. implicit spatial processing in arrow vs. eye-gaze spatial congruency effects

Arrows and gaze stimuli lead to opposite spatial congruency effects. While standard congruency effects are observed for arrows (faster responses for congruent conditions), responses are faster when eye-gaze stimuli are presented on the opposite side of the gazed-at location (incongruent trials), leading to a reversed congruency effect (RCE). Here, we explored the effects of implicit vs. explicit processing of arrows and eye-gaze direction. Participants were required to identify the direction (explicit task) or the colour (implicit task) of left or right looking/pointing gaze or arrows, presented to either the left or right of the fixation point. When participants responded to the direction of stimuli, standard congruency effects for arrows and RCE for eye-gaze stimuli were observed. However, when participants responded to the colour of stimuli, no congruency effects were observed. These results suggest that it is necessary to explicitly pay attention to the direction of eye-gaze and arrows for the congruency effect to occur. The same pattern of data was observed when participants responded either manually or verbally, demonstrating that manual motor components are not responsible for the results observed. These findings are not consistent with some hypotheses previously proposed to explain the RCE observed with eye-gaze stimuli and, therefore, call for an alternative plausible hypothesis.

Assessing the Sensitivity of EEG-Based Frequency-Tagging as a Metric for Statistical Learning.

Statistical learning (SL) is hypothesized to play an important role in language development. However, the measures typically used to assess SL, particularly at the level of individual participants, are largely indirect and have low sensitivity. Recently, a neural metric based on frequency-tagging has been proposed as an alternative measure for studying SL. We tested the sensitivity of frequency-tagging measures for studying SL in individual participants in an artificial language paradigm, using non-invasive electroencephalograph (EEG) recordings of neural activity in humans. Importantly, we used carefully constructed controls to address potential acoustic confounds of the frequency-tagging approach, and compared the sensitivity of EEG-based metrics to both explicit and implicit behavioral tests of SL. Group-level results confirm that frequency-tagging can provide a robust indication of SL for an artificial language, above and beyond potential acoustic confounds. However, this metric had very low sensitivity at the level of individual participants, with significant effects found only in 30% of participants. Comparison of the neural metric to previously established behavioral measures for assessing SL showed a significant yet weak correspondence with performance on an implicit task, which was above-chance in 70% of participants, but no correspondence with the more common explicit 2-alternative forced-choice task, where performance did not exceed chance-level. Given the proposed ubiquitous nature of SL, our results highlight some of the operational and methodological challenges of obtaining robust metrics for assessing SL, as well as the potential confounds that should be taken into account when using the frequency-tagging approach in EEG studies.

Metaphors for god: God is high, bright, and human in implicit tasks.

Metaphors for god: God is high, bright, and human in implicit tasks.

How accentuation influences the processing of emotional words in spoken language: An ERP study

Pitch accent marks information structure in utterances in many languages but little is known about the effects of accent on the perception of emotional word meaning. The present study explored the processing of accentuation and its influence on the semantic integration of emotional words during spoken sentence comprehension. Twenty-five participants were presented with sets of spoken Chinese sentences while accentuation and emotional meaning of the adjectives were orthogonally manipulated. An implicit task required the recognition of words contained in the sentences, whereas an explicit task required judging the presence of an accented or emotional word. In the ERPs to the adjectives, accentuation induced a long-lasting anterior negativity starting around 150–250 ms and a late posterior positivity. More importantly, emotionally negative words elicited larger negativities between 300 and 700 ms as compared to neutral words but only when they were accented. Interestingly, these negativities showed a parietal N400-typical distribution when accent was implicit but strongly overlapped with the accent-induced anterior negativity when accent was task-relevant. Hence, accentuation may enable the processing of emotional meaning by directing attention towards the accented words. When accent and emotion are explicit parts of the task, similar frontal attentional networks are activated by emotion as by accent alone. In contrast, when accent and emotion are implicit to the task, emotion appears to merely activate parietal networks, typical for semantic integration effects. Together, these results suggest that accentuation plays an important role in spoken sentence comprehension, deserving further study.