Refining ECG interpretation: from false assumptions to evidence-based precision

INTRODUCTION: Electrocardiography (ECG) remains a fundamental tool in cardiovascular diagnostics, frequently relying on System 1 thinking-rapid, intuitive pattern recognition (PR). However, this approach can be insufficient when dealing with complex cases where diagnostic precision is essential. This article emphasizes the importance of integrating System 2 thinking-a more deliberate, evidence-based approach-into ECG interpretation to enhance diagnostic accuracy and avoid clinical errors. METHODS: This review examines the distinction between findings that can be adequately managed through System 1 PR and those requiring System 2 reasoning supported by diagnostic accuracy studies. RESULTS: While System 1 PR is effective for recognizing routine ECG findings and self-evident truths, it falls short in conditions where the ECG serves as a mere surrogate marker for underlying pathology. Examples such as false-negative acute coronary occlusions illustrate the need for System 2 reasoning to account for the limitations of ECG's diagnostic precision. Relying solely on System 1 in these contexts risks treating the ECG as an infallible diagnostic tool and as a false gold standard for many diseases, which it is not. CONCLUSION: To prevent diagnostic errors, ECG interpretation must distinguish between self-evident truths suited for PR and findings that require System 2 reasoning due to their association with actual pathology. Clinicians and educators should prioritize evidence-based methods, incorporating System 2 reasoning into practice to improve diagnostic precision and patient outcomes.

Investigation of preference for local and global processing of Capuchin-monkeys (Sapajus spp.) in shape discrimination of mosaic arrangements.

Classical experiments using hierarchical stimuli to investigate the ability of capuchin monkeys to integrate visual information based on global or local clues reported findings suggesting a behavioral preference for local information of the image. Many experiments using mosaics have been conducted with capuchin monkeys to identify some of their perceptual phenotypes. As the identification of an image in a mosaic demands the integration of elements that share some visual features, we evaluated the discrimination of shapes presented in solid and mosaic stimuli in capuchin monkeys. Shape discrimination performance was tested in 2 male adult capuchin monkeys in an experimental chamber with a touchscreen video monitor, in three experiments: (i) evaluation of global and local processing using hierarchical stimuli; (ii) evaluation of target detection using simple discrimination procedures; (iii) evaluation of shape discrimination using simple discrimination and delayed matching-to-sample procedures. We observed that both monkeys had preferences for local processing when tested by hierarchical stimuli. Additionally, detection performance for solid and mosaic targets was highly significant, but for shape discrimination tasks we found significant performance when using solid figures, non-significant performance when using circle and square shapes in mosaic stimuli, and significant performance when using Letter X and Number 8 shapes in mosaic stimuli. Our results are suggestive that the monkeys respond to local contrast and partly to global contrast in mosaic stimuli.

Merging meaningful classes and abstract equivalence classes by exclusion.

The current experiment assessed whether relating abstract stimuli with familiar pictures by exclusion would produce the formation of a meaningful equivalence class. Ten participants learned conditional discrimination relations with abstract stimuli and established equivalence classes (ABC classes). They then learned DA (D1A1, D2A2, and D3A3) conditional discriminations with written words as D stimuli; two words (D1 and D2) were meaningful stimuli in the participants verbal community ("Dentist" and "Baker"), whereas the third (D3) was a pseudoword ("Tabilu"). In testing trials, participants evidenced derived relations between pictures related preexperimentally to D1 and D2 with the experimental equivalence classes related to D1 and D2. For some participants, the decontextualized stimuli were a set of boat pictures (Condition 1), whereas for others they were a set of miscellaneous pictures (Condition 2). Participants in both conditions successfully matched decontextualized pictures (unrelated to dentist and baker contexts) to all abstract stimuli in the class related to D3 (exclusion responding). In Condition 1 the meaning reported to the word Tabilu was similar across participants, but in Condition 2 participants showed more variations to answer to the meaning of Tabilu. These results suggest that exclusion learning can occur under different stimulus control topographies.

Novel object recognition in Octopus maya.

The Novel Object Recognition task (NOR) is widely used to study vertebrates' memory. It has been proposed as an adequate model for studying memory in different taxonomic groups, allowing similar and comparable results. Although in cephalopods, several research reports could indicate that they recognize objects in their environment, it has not been tested as an experimental paradigm that allows studying different memory phases. This study shows that two-month-old and older Octopus maya subjects can differentiate between a new object and a known one, but one-month-old subjects cannot. Furthermore, we observed that octopuses use vision and tactile exploration of new objects to achieve object recognition, while familiar objects only need to be explored visually. To our knowledge, this is the first time showing an invertebrate performing the NOR task similarly to how it is performed in vertebrates. These results establish a guide to studying object recognition memory in octopuses and the ontological development of that memory.

Human detection and motion recovery based on monocular vision / Detecção humana e recuperação de movimento com base na visão monocular / Detección humana y recuperación de movimiento basada en visión monocular

ABSTRACT Objective: Provides interactive games and human animation real motion data and technical options. Therefore, how to complete the position, attitude detection, and motion recovery under monocular vision has become an important research direction. Methods: This paper improves the part-based human detection algorithm and uses the AdaBoost multi-instance learning algorithm to train the part detector. Results: The results show that obtaining blood pressure waveform based on monocular vision pulse wave is feasible and has generalization. Conclusions: The results show the feasibility and accuracy of the gait motion detection, motion recovery and analysis system for human lower limbs based on monocular vision. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Objetivo: Fornece jogos interativos e dados de movimento real de animação humana e opções técnicas. Portanto, como completar a posição, detecção de atitude e recuperação de movimento sob visão monocular tornou-se uma importante direção de pesquisa. Métodos: este artigo aprimora o algoritmo de detecção humana baseado em partes e usa o algoritmo de aprendizado de múltiplas instâncias AdaBoost para treinar o detector de partes. Resultados: Os resultados mostram que o método de obtenção da forma de onda da pressão arterial com base na onda de pulso de visão monocular é viável e se pode generalizar. Conclusões: Os resultados mostram a viabilidade e precisão do sistema de detecção, recuperação e análise do movimento da marcha para membros inferiores humanos com base na visão monocular. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.

RESUMEN Objetivo: Proporciona juegos interactivos y animación humana, datos de movimiento real y opciones técnicas. Por lo tanto, cómo completar la posición, la detección de actitud y la recuperación de movimiento bajo visión monocular se ha convertido en una importante dirección de investigación. Métodos: este documento mejora el algoritmo de detección humana basado en piezas y utiliza el algoritmo de aprendizaje de instancias múltiples AdaBoost para entrenar el detector de piezas. Resultados: Los resultados muestran que el método de obtención de la forma de onda de la presión arterial basado en la onda de pulso de visión monocular es factible y se puede generalizar. Conclusiones: Los resultados muestran la viabilidad y precisión del sistema de detección, recuperación y análisis del movimiento de la marcha para miembros inferiores humanos basado en visión monocular. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.

Emotional categorization of objects: A novel clustering approach and the effect of depression.

Most everyday actions engender interactions with meaningful emotionally-laden stimuli. This study aimed to select pictures of objects as emotional stimulus of affordance to be grasped. The participant's depression trait was also assessed to examine its effect on the judgment of these pictures, and time spent in the classification was computed. Sixty-three participants joined this study. Self-Assessment-Manikin scale was used to classify pictures of the objects, and Beck Depression Inventory was applied to distribute the sample according depression trait. Cluster analysis was used in the classification of 123 objects based on valence and arousal values. Cluster results returned 102 classified pictures in three categories: pleasant (21), neutral (48) and unpleasant (33). Where cluster analysis did not agree, the picture was excluded and not used any further (21). Pleasant pictures presented the highest valence values and unpleasant pictures the lowest, and both categories returned the highest arousal level. In the middle of the valence range, the neutral category evoked the lowest arousal levels. Participants were slower to classify unpleasant pictures in valence sub-scale and faster to classify neutral pictures in arousal one. There was no effect of depression in the response time needed to score the pictures. Thus, agreement of high-performance soft clustering algorithms emerged as a good tool to classify pictures representing objects based on valence and arousal dimensions. Depression trait does not significantly affect the accuracy or time-order of emotional classification. Finally, we presented a set of emotional stimuli that can be employed to examine distinct aspects of emotion over physiology and behavior.

Flexible contextual modulation of naturalistic texture perception in peripheral vision.

Peripheral vision comprises most of our visual field, and is essential in guiding visual behavior. Its characteristic capabilities and limitations, which distinguish it from foveal vision, have been explained by the most influential theory of peripheral vision as the product of representing the visual input using summary statistics. Despite its success, this account may provide a limited understanding of peripheral vision, because it neglects processes of perceptual grouping and segmentation. To test this hypothesis, we studied how contextual modulation, namely the modulation of the perception of a stimulus by its surrounds, interacts with segmentation in human peripheral vision. We used naturalistic textures, which are directly related to summary-statistics representations. We show that segmentation cues affect contextual modulation, and that this is not captured by our implementation of the summary-statistics model. We then characterize the effects of different texture statistics on contextual modulation, providing guidance for extending the model, as well as for probing neural mechanisms of peripheral vision.

New insights on the ventral attention network: Active suppression and involuntary recruitment during a bimodal task.

Detection of unexpected, yet relevant events is essential in daily life. fMRI studies have revealed the involvement of the ventral attention network (VAN), including the temporo-parietal junction (TPJ), in such process. In this MEG study with 34 participants (17 women), we used a bimodal (visual/auditory) attention task to determine the neuronal dynamics associated with suppression of the activity of the VAN during top-down attention and its recruitment when information from the unattended sensory modality is involuntarily integrated. We observed an anticipatory power increase of alpha/beta oscillations (12-20 Hz, previously associated with functional inhibition) in the VAN following a cue indicating the modality to attend. Stronger VAN power increases were associated with better task performance, suggesting that the VAN suppression prevents shifting attention to distractors. Moreover, the TPJ was synchronized with the frontal eye field in that frequency band, indicating that the dorsal attention network (DAN) might participate in such suppression. Furthermore, we found a 12-20 Hz power decrease and enhanced synchronization, in both the VAN and DAN, when information between sensory modalities was congruent, suggesting an involvement of these networks when attention is involuntarily enhanced due to multisensory integration. Our results show that effective multimodal attentional allocation includes the modulation of the VAN and DAN through upper-alpha/beta oscillations. Altogether these results indicate that the suppressing role of alpha/beta oscillations might operate beyond sensory regions.

Selective Inhibition of Mirror Invariance for Letters Consolidated by Sleep Doubles Reading Fluency.

Mirror invariance is a visual mechanism that enables a prompt recognition of mirror images. This visual capacity emerges early in human development, is useful to recognize objects, faces, and places from both left and right perspectives, and is also present in primates, pigeons, and cephalopods. Notwithstanding, the same visual mechanism has been suspected to be the source of a specific difficulty for a relatively recent human invention-reading-by creating confusion between mirror letters (e.g., b-d in the Latin alphabet). Using an ecologically valid school-based design, we show here that mirror invariance represents indeed a major leash for reading fluency acquisition in first graders. Our causal approach, which specifically targeted mirror invariance inhibition for letters, in a synergic combination with post-training sleep to increase learning consolidation, revealed unprecedented improvement in reading fluency, which became two-times faster. This gain was obtained with as little as 7.5 h of multisensory-motor training to distinguish mirror letters, such as "b" versus "d." The magnitude, automaticity, and duration of this mirror discrimination learning were greatly enhanced by sleep, which keeps the gains perfectly intact even after 4 months. The results were consistently replicated in three randomized controlled trials. They not only reveal an extreme case of cognitive plasticity in humans (i.e., the inhibition in just 3 weeks of a ∼25-million-year-old visual mechanism), that allows adaptation to a cultural activity (reading), but at the same time also show a simple and cost-effective way to unleash the reading fluency potential of millions of children worldwide.

Specificity of the chromatic noise influence on the luminance contrast discrimination to the color vision phenotype.

Many studies have examined how color and luminance information are processed in the visual system. It has been observed that chromatic noise masked luminance discrimination in trichromats and that luminance thresholds increased as a function of noise saturation. Here, we aimed to compare chromatic noise inhibition on the luminance thresholds of trichromats and subjects with severe deutan or protan losses. Twenty-two age-matched subjects were evaluated, 12 trichromats and 10 with congenital color vision impairment: 5 protanopes/protanomalous, and 5 deuteranopes/deuteranomalous. We used a mosaic of circles containing chromatic noise consisting of 8 chromaticities around protan, deutan, and tritan confusion lines. A subset of the circles differed in the remaining circles by the luminance arising from a C-shaped central target. All the participants were tested in 4 chromatic noise saturation conditions (0.04, 0.02, 0.01, 0.005 u'v' units) and 1 condition without chromatic noise. We observed that trichromats had an increasing luminance threshold as a function of chromatic noise saturation under all chromatic noise conditions. The subjects with color vision deficiencies displayed no changes in the luminance threshold across the different chromatic noise saturations when the noise was composed of chromaticities close to their color confusion lines (protan and deutan chromatic noise). However, for tritan chromatic noise, they were found to have similar results to the trichromats. The use of chromatic noise masking on luminance threshold estimates could help to simultaneously examine the processing of luminance and color information. A comparison between luminance contrast discrimination obtained from no chromatic and high-saturated chromatic noise conditions could be initially undertaken in this double-duty test.

Effects of load and emotional state on EEG alpha-band power and inter-site synchrony during a visual working memory task.

Motivationally/emotionally engaging stimuli are strong competitors for the limited capacity of sensory and cognitive systems. Thus, they often act as distractors, interfering with performance in concurrent primary tasks. Keeping task-relevant information in focus while suppressing the impact of distracting stimuli is one of the functions of working memory (WM). Macroscopic brain oscillations in the alpha band (8-13 Hz) have recently been identified as a neural correlate of WM processing. Using electroencephalography, we examined the extent to which changes in alpha power and inter-site connectivity during a typical WM task are sensitive to load and emotional distraction. Participants performed a lateralized change-detection task with two levels of load (four vs. two items), which was preceded by naturalistic scenes rated either as unpleasant or neutral, acting as distractors. The results showed the expected parieto-occipital alpha reduction in the hemisphere contralateral to the WM task array, compared to the ipsilateral hemisphere, during the retention interval. Selectively heightened oscillatory coupling between frontal and occipital sensors was observed (1) during the retention interval as a function of load, and (2) upon the onset of the memory array, after viewing neutral compared to unpleasant distractors. At the end of the retention interval, we observed greater coupling during the unpleasant compared to the neutral condition. These findings are consistent with the notions that (1) representing more items in WM requires greater interconnectivity across cortical areas, and (2) unpleasant emotional distractors interfere with subsequent WM processing by disrupting processing during the encoding stage.

Intragroup differences and similarities in performance on rapid automatized naming tasks in children with ADHD symptoms, children with reading disabilities, and controls.

Introduction Rapid automatized naming (RAN) is the ability to name, as fast as possible, symbols such as letters, digits and figures. The present study aimed to investigate intragroup performance patterns on RAN tasks in children with attention deficit hyperactivity disorder (ADHD) symptoms alone, children with reading disability (RD) alone and controls with typical development. Methods A total of 216 Brazilian children between 8 to 11 years old were selected from public schools located in two Brazilian capitals, namely Porto Alegre and Belo Horizonte, to participate in the study. Mixed 3 (participant group: ADHD symptoms, RD or control group) × 3 (type of stimulus: letters, numbers or figures) ANOVAs were performed using response time and number of errors as dependent variables. Only intragroup comparisons are described in this paper. Results The groups with ADHD symptoms and RD showed similar performance results on naming speed. There were no differences between letters and numbers within each group, but we found slower responses in figure naming compared to the other tasks for both groups. Concerning accuracy, children with ADHD symptoms showed a similar number of errors in all three tasks. These patterns were distinct from the performance of the control group. Conclusion Results suggest a shared deficit in naming speed of alphanumeric stimuli in children with ADHD symptoms and those with RD, and impairments in naming digits correctly in children with ADHD symptoms.

Intragroup differences and similarities in performance on rapid automatized naming tasks in children with ADHD symptoms, children with reading disabilities, and controls

Abstract Introduction Rapid automatized naming (RAN) is the ability to name, as fast as possible, symbols such as letters, digits and figures. The present study aimed to investigate intragroup performance patterns on RAN tasks in children with attention deficit hyperactivity disorder (ADHD) symptoms alone, children with reading disability (RD) alone and controls with typical development. Methods A total of 216 Brazilian children between 8 to 11 years old were selected from public schools located in two Brazilian capitals, namely Porto Alegre and Belo Horizonte, to participate in the study. Mixed 3 (participant group: ADHD symptoms, RD or control group) × 3 (type of stimulus: letters, numbers or figures) ANOVAs were performed using response time and number of errors as dependent variables. Only intragroup comparisons are described in this paper. Results The groups with ADHD symptoms and RD showed similar performance results on naming speed. There were no differences between letters and numbers within each group, but we found slower responses in figure naming compared to the other tasks for both groups. Concerning accuracy, children with ADHD symptoms showed a similar number of errors in all three tasks. These patterns were distinct from the performance of the control group. Conclusion Results suggest a shared deficit in naming speed of alphanumeric stimuli in children with ADHD symptoms and those with RD, and impairments in naming digits correctly in children with ADHD symptoms.

Single Neuron Coding of Identity in the Human Hippocampal Formation.

Experimental findings show the ubiquitous presence of graded responses and tuning curves in the neocortex, particularly in visual areas [1-15]. Among these, inferotemporal-cortex (IT) neurons respond to complex visual stimuli, but differences in the neurons' responses can be used to distinguish the stimuli eliciting the responses [8, 9, 16-18]. The IT projects directly to the medial temporal lobe (MTL) [19], where neurons respond selectively to different pictures of specific persons and even to their written and spoken names [20-22]. However, it is not clear whether this is done through a graded coding, as in the neocortex, or a truly invariant code, in which the response-eliciting stimuli cannot be distinguished from each other. To address this issue, we recorded single neurons during the repeated presentation of different stimuli (pictures and written and spoken names) corresponding to the same persons. Using statistical tests and a decoding approach, we found that only in a minority of cases can the different pictures of a given person be distinguished from the neurons' responses and that in a larger proportion of cases, the responses to the pictures were different to the ones to the written and spoken names. We argue that MTL neurons tend to lack a representation of sensory features (particularly within a sensory modality), which can be advantageous for the memory function attributed to this area [23-25], and that a full representation of memories is given by a combination of mostly invariant coding in the MTL with a representation of sensory features in the neocortex.

Brain Structural-Functional Connectivity Relationship Underlying the Information Processing Speed.

Human cognition and behavior emerge from neuronal interactions on a brain structural architecture. The convergence (or divergence) between functional dynamics and structural connectivity (SC) and their relationship with cognition are still a pivotal question about the brain. We focused on the information processing speed (IPS), assessed by the Symbol Digit Modalities Test (SDMT), once delayed IPS underlies attention deficits in various clinical conditions. We hypothesize that the SC constrains but does not determine functional connectivity, and such a relationship is related to the cognitive performance. Blood oxygenation level-dependent and diffusion tensor images of healthy young volunteers were acquired in a 3T magnetic resonance imaging machine. Activation maps included the left and right middle frontal gyri, left superior parietal lobule, left precuneus, left inferior frontal gyrus (IFG), right cuneus, left lingual gyrus, and left declive. A network involving such regions and signal propagation from visual, through cognitive, up to motor regions was proposed. Random effects Bayesian model selection showed that the top-down connections have the highest expected and exceedance probabilities. Moreover, all pairs of task-related regions were connected by at least one tract, except for the left declive with the left IFG. The interactions between the right cuneus with left declive were related to the interindividual variability in SDMT performance. Altogether, our findings suggest that the IPS functional network is related to the highest SDMT scores when its effective endogenous connections are suppressed to the detriment of modulation caused by the experimental conditions, with the underlying structure providing low diffusion environments.

Adjective Learning by Spanish-Speakers Children and Adults. The Impact of Morphology and Semantic Information.

The purpose of this research was to explore the kind of information Spanish-speaking 3-year-old children and adults use when learning adjectives in a joint picturebook reading situation. The impact of two linguistic clues was studied; a morphological clue (adjective suffix) and a semantic clue (descriptive information concerning the property). Results show that for children the description was decisive to map the new adjective with the property; for adults, instead, the presence of the suffix was crucial. These results illustrate a developmental shift in the sort of clues that shapes adjective learning.

Perceptual inhibition of emotional interference in children.

In daily life, when a bee approaches us while we are sitting in the garden, we must pay attention to that threatening stimulus and give an appropriate response. However, if this bee approaches us while riding a bike, we must inhibit that distractor to avoid an accident. In this case, avoiding the interference of an emotional stimuli and continuing with the task should be preferential. In general, perceptual inhibition is responsible for controlling and suppressing the environmental distractions that interrupt the course of the realization of a goal. In this study, 435 children performed a modified flanker task with entirely irrelevant emotional and neutral stimuli in order to assess perceptual inhibition in contexts with high and low emotional salience. The results showed that entirely irrelevant distractors affected performance, but that there were no significant differences according to whether these distractors were emotionally salient or neutral. These results constitute a first approach to the problem of emotional interference in children considering the multidimensional approach of inhibition.

The effect of conditioned inhibitors and preexposed cues on the outcome-specific Pavlovian-to-instrumental transfer effect in humans.

Using a human Pavlovian-to-instrumental transfer (PIT) task, Alarcón and Bonardi showed that the selective elevation of instrumental responding produced by excitatory transfer cues was reduced when these cues were presented with a conditioned inhibitor (CI), relative to a control cue that was simply preexposed. However, previous research has shown that preexposed cues might also acquire inhibitor-like properties. This study aimed to contrast the inhibitory properties of CIs and preexposed cues, using novel stimuli as controls, in summation and PIT tests. Participants were trained to perform two actions, each reinforced with a distinct outcome (O1 or O2). Two images were trained as CIs, each signalling the absence of one of the outcomes, by presenting them with a cue that was otherwise followed by that outcome (e.g., A→O1, AI→no O1). In contrast, the preexposed cues were simply presented in the absence of the outcomes. In the summation test, participants rated the likelihood of the outcomes in the presence of two independently trained excitatory cues, each presented with a CI, a preexposed cue, or a novel stimulus. Similarly, in the PIT test, participants performed both actions in the presence and absence of these compounds. In the summation test, the CIs and the preexposed cues reduced participants' expectations of the outcomes more than the novel stimuli. However, in the PIT test, only the CIs reduced the selective elevation of responding produced by the transfer cues. These results might reflect distinct properties of stimuli trained as CIs and those simply preexposed.

The effects of using hearing aids and a frequency modulated system on listening effort among adolescents with hearing loss.

Objective: To develop a web-based application for a colour pattern memory recognition task as the secondary task of a dual-task paradigm and to compare the listening effort required by adolescents with hearing loss (HL) under two conditions (HA and HA + FM system), to adolescents with normal hearing (NH).Design: Cohort study. The participants underwent a dual-task paradigm, including the Hearing in Noise Test as the primary task and a colour memory task as the secondary task. A platform, PALETA, was developed to assess the secondary task.Study sample: In total, 31 adolescents were enrolled, of which 13 adolescents had HL and 18 adolescents had NH (mean age, 14 years).Results: Adolescents with NH scored significantly better on the secondary task compared to participants with HL using a HA. However, on analysing response time, no significant differences were observed among the groups.Conclusion: PALETA is proposed as a test procedure for the secondary task. The results revealed that the use of an FM system reduces the listening effort that adolescents with HL deploy to recognise speech in noise, and that listening effort data by number of correct responses is a way of investigating the benefits of using FM system.