Social and communicative not a prerequisite: Preverbal infants learn an abstract rule only from congruent audiovisual dynamic pitch-height patterns.

Learning in the everyday environment often requires the flexible integration of relevant multisensory information. Previous research has demonstrated preverbal infants' capacity to extract an abstract rule from audiovisual temporal sequences matched in temporal synchrony. Interestingly, this capacity was recently reported to be modulated by crossmodal correspondence beyond spatiotemporal matching (e.g., consistent facial emotional expressions or articulatory mouth movements matched with sound). To investigate whether such modulatory influence applies to non-social and non-communicative stimuli, we conducted a critical test using audiovisual stimuli free of social information: visually upward (and downward) moving objects paired with a congruent tone of ascending or incongruent (descending) pitch. East Asian infants (8-10 months old) from a metropolitan area in Asia demonstrated successful abstract rule learning in the congruent audiovisual condition and demonstrated weaker learning in the incongruent condition. This implies that preverbal infants use crossmodal dynamic pitch-height correspondence to integrate multisensory information before rule extraction. This result confirms that preverbal infants are ready to use non-social non-communicative information in serving cognitive functions such as rule extraction in a multisensory context.

Different Mechanisms for Visual Attention at the Hand-movement Goal and Endogenous Visual Attention.

Visual perception is closely related to body movements and action, and it is known that processing visual stimuli is facilitated at the hand or at the hand-movement goal. Such facilitation suggests that there may be an attentional process associated with the hands or hand movements. To investigate the underlying mechanisms of visual attention at a hand-movement goal, we conducted two experiments to examine whether attention at the hand-movement goal is a process independent from endogenous attention. Endogenous attention is attention that is intentionally focused on a location, feature, or object. We controlled the hand-movement goal and endogenous attention separately to investigate the spatial profiles of the two types of attention. A visual target was presented either at the goal of hand movement (same condition) or at its opposite side (opposite condition) while steady-state visual-evoked potential (SSVEP) was used to estimate the spatial distributions of the facilitation effect from the 2 types of attention around the hand-movement goal and around the visual target through EEG. We estimated the spatial profile of attentional modulation for the hand-movement goal by taking the difference in SSVEP amplitude between conditions with and without hand movement, thereby obtaining the effect of visual endogenous attention alone. The results showed a peak at the hand-movement goal, independent of the location of the visual target where participants intentionally focused their attention (endogenous attention). We also found differences in the spatial extent of attentional modulation. Spatial tuning was narrow around the hand-movement goal (i.e., attentional facilitation only at the goal location) but was broadly tuned around the focus of endogenous attention (i.e., attentional facilitation spreading over adjacent stimulus locations), which was obtained from the condition without hand movement. These results suggest the existence of two separate mechanisms, one underlying the attention at the hand-movement goal and another underlying endogenous attention.

Gestalt neurons and emergent properties in visual perception: A novel concept for the transformation from local to global processing.

Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of inherent principles, the Laws of Seeing. This review attempts to assign neurophysiological correlates to select emergent properties in motion and contour perception and proposes parallels to the processing of local versus global attributes by classical versus contextual receptive fields. The aim is to identify Gestalt neurons in the visual system to account for the Laws of Seeing in causal terms and to explain "Why do things look as they do" (Koffka, 1935, p. 76).

Promoting healthy eating and active playtime by connecting to nature families with preschool children: evaluation of pilot study "Play&Grow".

BACKGROUND: This pilot project aimed to evaluate the "Play&Grow" program which promotes age-appropriate dietary habits and playtime healthy routines through "connectedness to nature" experiences in Hong Kong families with young children. METHOD: Thirty-eight preschoolers (aged 33.97 ± 9.38 mo), mothers, and their domestic workers were recruited. The families attended one workshop/week for a 4-mo period, consisting of: (i) health topic; (ii) food games; (iii) nature-related outdoor activities. RESULTS: Feeding practices, particularly Promoting and Encouragement to eat (PE) and Instrumental Feeding (IF) improved after the intervention (P = 0.008 and P = 0.016, respectively). Mother's BMI, responsibility for child's meal, child's birth weight had a bearing on the improvement of PE, r2 = 0.243, F(3,33) = 3.54, P = 0.025. Domestic helper's responsibility for child's cooking and her IF practices could predict child's picky eating (r2 = 0.203, F(2,34) = 4.322, P = 0.021). Mother's responsibility for child and helper's responsibility for cooking could predict child's consumption of salty foods (r2 = 0.252, F(2,34) = 5.737, P = 0.007). Physical activity of caregivers improved after the intervention. CONCLUSION: The pilot confirmed the design, protocols, evaluation instruments, and logistics of the study. Modified "Play&Grow" intervention will be conducted in a more rigorous randomized controlled trial to determine the long-term impact on obesity prevention in Hong Kong.

Bimodal emotion congruency is critical to preverbal infants' abstract rule learning.

Extracting general rules from specific examples is important, as we must face the same challenge displayed in various formats. Previous studies have found that bimodal presentation of grammar-like rules (e.g. ABA) enhanced 5-month-olds' capacity to acquire a rule that infants failed to learn when the rule was presented with visual presentation of the shapes alone (circle-triangle-circle) or auditory presentation of the syllables (la-ba-la) alone. However, the mechanisms and constraints for this bimodal learning facilitation are still unknown. In this study, we used audio-visual relation congruency between bimodal stimulation to disentangle possible facilitation sources. We exposed 8- to 10-month-old infants to an AAB sequence consisting of visual faces with affective expressions and/or auditory voices conveying emotions. Our results showed that infants were able to distinguish the learned AAB rule from other novel rules under bimodal stimulation when the affects in audio and visual stimuli were congruently paired (Experiments 1A and 2A). Infants failed to acquire the same rule when audio-visual stimuli were incongruently matched (Experiment 2B) and when only the visual (Experiment 1B) or the audio (Experiment 1C) stimuli were presented. Our results highlight that bimodal facilitation in infant rule learning is not only dependent on better statistical probability and redundant sensory information, but also the relational congruency of audio-visual information. A video abstract of this article can be viewed at https://m.youtube.com/watch?v=KYTyjH1k9RQ.

Eye of origin guides attention away: An ocular singleton column impairs visual search like a collinear column.

Collinearity and eye of origin were recently discovered to guide attention: Target search is impaired if it is overlapping with a collinear structure (Jingling & Tseng, 2013) but enhanced if the target is an ocular singleton (Zhaoping, 2008). Both are proposed to occur in V1, and we study their interaction here. In our 9 × 9 search display (Experiment 1), all columns consisted of horizontal bars except for one randomly selected column that contained orthogonal bars (collinear distractor). All columns were presented to one eye except for a randomly selected column that was presented to the other eye (ocular distractor). The target could be located on a distractor column (collinear congruent [CC]/ocular congruent [OC]) or not (collinear incongruent [CI]/ocular incongruent [OI]). We expected to find the best search performance for OC + CI targets and the worst search performance for OI + CC targets. The other combinations would depend on the relative strength of collinearity and ocular information in guiding attention. As expected, we observed collinear impairment, but surprisingly, we did not observe any search advantage for OC targets. Our subsequent experiments confirmed that OC search impairment also occurred when color-defined columns (Experiment 2), ocular singletons (Experiments 4 and 5), and noncollinear columns (Experiment 5) were used instead of collinear columns. However, the ocular effect disappeared when paired with luminance-defined columns (Experiments 3A and 3B). Although our results agree well with earlier findings that eye-of-origin information guides attention, they highlight that our previous understanding of search advantage by ocular singleton targets might have been oversimplified.

Invisible collinear structures impair search.

Visual attention and perceptual grouping both help us from being overloaded by the vast amount of information, and attentional search is delayed when a target overlaps with a snake-like collinear distractor (Jingling & Tseng, 2013). We assessed whether awareness of the collinear distractor is required for this modulation. We first identified that visible long (=9 elements), but not short (=3 elements) collinear distractor slowed observers' detection of an overlapping target. Then we masked part of a long distractor (=9 elements) with continuous flashing color patches (=6 elements) so that the combined dichoptic percept to observers' awareness was a short collinear distractor (=3 elements). We found that the invisible collinear parts, like visible ones, can form a continuous contour to impair search, suggesting that conscious awareness is not a pre-requisite for contour integration and its interaction with selective attention.

Beyond the classical receptive field: The effect of contextual stimuli.

Following the pioneering studies of the receptive field (RF), the RF concept gained further significance for visual perception by the discovery of input effects from beyond the classical RF. These studies demonstrated that neuronal responses could be modulated by stimuli outside their RFs, consistent with the perception of induced brightness, color, orientation, and motion. Lesion scotomata are similarly modulated perceptually from the surround by RFs that have migrated from the interior to the outer edge of the scotoma and in this way provide filling-in of the void. Large RFs are advantageous to this task. In higher visual areas, such as the middle temporal and inferotemporal lobe, RFs increase in size and lose most of their retinotopic organization while encoding increasingly complex features. Whereas lower-level RFs mediate perceptual filling-in, contour integration, and figure-ground segregation, RFs at higher levels serve the perception of grouping by common fate, biological motion, and other biologically relevant stimuli, such as faces. Studies in alert monkeys while freely viewing natural scenes showed that classical and nonclassical RFs cooperate in forming representations of the visual world. Today, our understanding of the mechanisms underlying the RF is undergoing a quantum leap. What had started out as a hierarchical feed-forward concept for simple stimuli, such as spots, lines, and bars, now refers to mechanisms involving ascending, descending, and lateral signal flow. By extension of the bottom-up paradigm, RFs are nowadays understood as adaptive processors, enabling the predictive coding of complex scenes. Top-down effects guiding attention and tuned to task-relevant information complement the bottom-up analysis.

The relation among sleep duration, homework burden, and sleep hygiene in chinese school-aged children.

Insufficient sleep in school-aged children is common in modern society, with homework burden being a potential risk factor. The aim of this article is to explore the effect of sleep hygiene on the association between homework and sleep duration. Children filled out the Chinese version of the Adolescent Sleep Hygiene Scale, and parents filled out a sociodemographic questionnaire. The final sample included 363 boys and 371 girls with a mean age of 10.82 ± 0.38 years. Children with more homework went to bed later and slept less. Better sleep hygiene was associated with earlier bedtimes and longer sleep duration. Findings suggest that homework burden had a larger effect on sleep duration than sleep hygiene. Fifth-grade children in Shanghai have an excessive homework burden, which overwrites the benefit of sleep hygiene on sleep duration.

Falling skyscrapers: when cross-modal perception of verticality fails.

The perception of verticality is critical for balance control and interaction with the world. But this complex process fails badly under certain circumstances-usually as the result of an illusion. Here, we report on a real-world example of how the brain fails to disregard body position on a moving mountain tram and adopts an inappropriate frame of reference, which prompts passengers to perceive skyscrapers leaning by as much as 30°. To elucidate the sensory origin of this misperception, we conducted field experiments on the moving tram to systematically disentangle the contributions of four sensory systems known to affect verticality perception, namely, vestibular, tactile, proprioceptive, and visual cues. Our results refute the intuitive assumption that the perceived tilt of the buildings is based on visual error signals and demonstrate instead that a unified percept of verticality is a product of the synergistic interaction among multiple sensory systems and the contextual information available in the real world.

Collinear integration affects visual search at V1.

Perceptual grouping plays an indispensable role in figure-ground segregation and attention distribution. For example, a column pops out if it contains element bars orthogonal to uniformly oriented element bars. Jingling and Tseng (2013) have reported that contextual grouping in a column matters to visual search behavior: When a column is grouped into a collinear (snakelike) structure, a target positioned on it became harder to detect than on other noncollinear (ladderlike) columns. How and where perceptual grouping interferes with selective attention is still largely unknown. This article contributes to this little-studied area by asking whether collinear contour integration interacts with visual search before or after binocular fusion. We first identified that the previously mentioned search impairment occurs with a distractor of five or nine elements but not one element in a 9 × 9 search display. To pinpoint the site of this effect, we presented the search display with a short collinear bar (one element) to one eye and the extending collinear bars to the other eye, such that when properly fused, the combined binocular collinear length (nine elements) exceeded the critical length. No collinear search impairment was observed, implying that collinear information before binocular fusion shaped participants' search behavior, although contour extension from the other eye after binocular fusion enhanced the effect of collinearity on attention. Our results suggest that attention interacts with perceptual grouping as early as V1.

Orientation is different: Interaction between contour integration and feature contrasts in visual search.

Salient items usually capture attention and are beneficial to visual search. Jingling and Tseng (2013), nevertheless, have discovered that a salient collinear column can impair local visual search. The display used in that study had 21 rows and 27 columns of bars, all uniformly horizontal (or vertical) except for one column of bars orthogonally oriented to all other bars, making this unique column of collinear (or noncollinear) bars salient in the display. Observers discriminated an oblique target bar superimposed on one of the bars either in the salient column or in the background. Interestingly, responses were slower for a target in a salient collinear column than in the background. This opens a theoretical question of how contour integration interacts with salience computation, which is addressed here by an examination of how salience modulated the search impairment from the collinear column. We show that the collinear column needs to have a high orientation contrast with its neighbors to exert search interference. A collinear column of high contrast in color or luminance did not produce the same impairment. Our results show that orientation-defined salience interacted with collinear contour differently from other feature dimensions, which is consistent with the neuronal properties in V1.

Salient collinear grouping diminishes local salience in visual search: an eye movement study.

Our eyes and attention are easily attracted to salient items in search displays. When a target is spatially overlapped with a salient distractor (overlapping target), it is usually detected more easily than when it is not (nonoverlapping target). Jingling and Tseng (2013), however, found that a salient distractor impaired visual search when the distractor was comprised of more than nine bars collinearly aligned to each other. In this study, we examined whether this search impairment is due to reduction of salience on overlapping targets. We used the short-latency saccades as an index for perceptual salience. Results showed that a long collinear distractor decreases perceptual salience of local overlapping targets in comparison to nonoverlapping targets, reflected by a smaller proportion of the short-latency saccades. Meanwhile, a salient noncollinear distractor increases salience of overlapping targets. Our results led us to conclude that a long collinear distractor diminishes the perceptual salience of the target, a factor which poses a counter-intuitive condition in which a target on a salient region becomes less salient. We discuss the possible causes for our findings, including crowding, the global precedence effect, and the filling-in of a collinear contour.

Social affiliation is sufficient to provoke the partner-advantage.

The partner-advantage is a type of identity-priority processing that we afford to a person with whom we perform a task together 1. The partner-advantage has been revealed by shortened reaction time (RT) and enhanced accuracy when participants learned to match a shape with an associated name. It is distinguished from other long-lasting and robust identity advantages (e.g., self-advantage and friend-advantage) by its instantaneous build-up and quick reduction; however, its characteristics and enabling factors remain unknown. The present study addresses these questions. In Experiment 1, we replicated the partner-advantage in a solo shape-name matching task (i.e., without a social component) in which other identity biases are usually reported. In Experiment 2, an absent partner (who did not appear physically) was sufficient to induce beneficial partner-related processing, with a temporary partner enjoying a benefit similar to that of significant others. In Experiment 3, an identity low in socially affiliated significance (e.g., another participant in the same experiment) did not automatically enjoy a priority bias. Taken together, our results suggest that the bias toward partners, similar to other known identity biases, does not require physical presence to build and maintain a referential advantage. The partner-advantage does not automatically extend to other social affiliations, and a joint task is not a pre-requisite to produce the bias. Our study offers new insights on identity-referential processing and its underlying mechanisms.

Body Pitch Together With Translational Body Motion Biases the Subjective Haptic Vertical.

Accurate perception of verticality is critical for postural maintenance and successful physical interaction with the world. Although previous research has examined the independent influences of body orientation and self-motion under well-controlled laboratory conditions, these factors are constantly changing and interacting in the real world. In this study, we examine the subjective haptic vertical in a real-world scenario. Here, we report a bias of verticality perception in a field experiment on the Hong Kong Peak Tram as participants traveled on a slope ranging from 6° to 26°. Mean subjective haptic vertical (SHV) increased with slope by as much as 15°, regardless of whether the eyes were open (Experiment 1) or closed (Experiment 2). Shifting the body pitch by a fixed degree in an effort to compensate for the mountain slope failed to reduce the verticality bias (Experiment 3). These manipulations separately rule out visual and vestibular inputs about absolute body pitch as contributors to our observed bias. Observations collected on a tram traveling on level ground (Experiment 4A) or in a static dental chair with a range of inclinations similar to those encountered on the mountain tram (Experiment 4B) showed no significant deviation of the subjective vertical from gravity. We conclude that the SHV error is due to a combination of large, dynamic body pitch and translational motion. These observations made in a real-world scenario represent an incentive to neuroscientists and aviation experts alike for studying perceived verticality under field conditions and raising awareness of dangerous misperceptions of verticality when body pitch and translational self-motion come together.

Contribution of the slow motion mechanism to global motion revealed by an MAE technique.

Two different motion mechanisms have been identified with motion aftereffect (MAE). (1) A slow motion mechanism, accessed by a static MAE, is sensitive to high-spatial and low-temporal frequency; (2) a fast motion mechanism, accessed by a flicker MAE, is sensitive to low-spatial and high-temporal frequency. We examined their respective responses to global motion after adapting to a global motion pattern constructed of multiple compound Gabor patches arranged circularly. Each compound Gabor patch contained two gratings at different spatial frequencies (0.53 and 2.13 cpd) drifting in opposite directions. The participants reported the direction and duration of the MAE for a variety of global motion patterns. We discovered that static MAE durations depended on the global motion patterns, e.g., longer MAE duration to patches arranged to see rotation than to random motion (Exp 1), and increase with global motion strength (patch number in Exp 2). In contrast, flicker MAEs durations are similar across different patterns and adaptation strength. Further, the global integration occurred at the adaptation stage, rather than at the test stage (Exp 3). These results suggest that slow motion mechanism, assessed by static MAE, integrate motion signals over space while fast motion mechanisms do not, at least under the conditions used.

Collinear search impairment is luminance contrast invariant.

Collinear search impairment (CSI) is a phenomenon where a task-irrelevant collinear structure impairs a target search in a visual display. It has been suggested that CSI is monocular, occurs without the participants' access to consciousness and is possibly processed at an early visual site (e.g. V1). This effect has frequently been compared with a well-documented opposite effect called attentional capture (AC), in which salient and task-irrelevant basic features (e.g. color, orientation) enhance target detection. However, whether this phenomenon can be attributed to non-attentional factors such as collinear facilitation (CF) has not yet been formally tested. Here we used one well-established property of CF, i.e. that target contrast modulates its effect direction (facilitation vs suppression), to examine whether CSI shared similar signature profiles along different contrast levels. In other words, we tested whether CSI previously observed at the supra-threshold level was reduced or reversed at near-threshold contrast levels. Our results showed that, regardless of the luminance contrast levels, participants spent a longer time searching for targets displayed on the salient singleton collinear structure than those displayed off the structure. Contrast invariance suggests that it is unlikely that CSI is exclusively sub-served by an early vision mechanism (e.g. CF).

Team Flow Is a Unique Brain State Associated with Enhanced Information Integration and Interbrain Synchrony.

Team flow occurs when a group functions in a high task engagement to achieve a goal, commonly seen in performance and sports. Team flow can enable enhanced positive experiences, as compared with individual flow or regular socializing. However, the neural basis for this enhanced behavioral state remains unclear. Here, we identified neural correlates (NCs) of team flow in human participants using a music rhythm task with electroencephalogram hyperscanning. Experimental manipulations held the motor task constant while disrupting the corresponding hedonic music to interfere with the flow state or occluding the partner's positive feedback to impede team interaction. We validated these manipulations by using psychometric ratings and an objective measure for the depth of flow experience, which uses the auditory-evoked potential (AEP) of a task-irrelevant stimulus. Spectral power analysis at both the scalp sensors and anatomic source levels revealed higher ß-γ power specific to team flow in the left middle temporal cortex (L-MTC). Causal interaction analysis revealed that the L-MTC is downstream in information processing and receives information from areas encoding the flow or social states. The L-MTC significantly contributes to integrating information. Moreover, we found that team flow enhances global interbrain integrated information (II) and neural synchrony. We conclude that the NCs of team flow induce a distinct brain state. Our results suggest a neurocognitive mechanism to create this unique experience.

Long-lasting sensitization to a given colour after visual search.

Visual attention enables an observer to select specific visual information for processing. In an ambiguous motion task in which a coloured grating can be perceived as moving in either of two opposite directions depending on the relative salience of two colours in the display, attending to one of the colours influences the direction in which the grating appears to move. Here, we use this secondary effect of attention in a motion task to measure the effect of attending to a specific colour in a search task. Observers performed a search task in which they searched for a target letter in a 4 x 4 coloured matrix. Each of the 16 squares within a matrix was assigned one of four colours, and observers knew that the target letter would appear on only one of these colours throughout the experiment. Observers performed the ambiguous motion task before and after the search task. Attending to a particular colour for a brief period in the search task profoundly influenced the perceived direction of motion. This effect lasted for up to one month and in some cases had to be reversed by practising searches for the complementary colour, indicating a much longer-persisting effect of attention than has been observed previously.

Subjective discriminability of invisibility: a framework for distinguishing perceptual and attentional failures of awareness.

Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.