Quantitative multidimensional phenotypes improve genetic analysis of laterality traits.

Handedness is the most commonly investigated lateralised phenotype and is usually measured as a binary left/right category. Its links with psychiatric and neurodevelopmental disorders prompted studies aimed at understanding the underlying genetics, while other measures and side preferences have been less studied. We investigated the heritability of hand, as well as foot, and eye preference by assessing parental effects (n ≤ 5028 family trios) and SNP-based heritability (SNP-h2, n ≤ 5931 children) in the Avon Longitudinal Study of Parents and Children (ALSPAC). An independent twin cohort from Hong Kong (n = 358) was used to replicate results from structural equation modelling (SEM). Parental left-side preference increased the chance of an individual to be left-sided for the same trait, with stronger maternal than paternal effects for footedness. By regressing out the effects of sex, age, and ancestry, we transformed laterality categories into quantitative measures. The SNP-h2 for quantitative handedness and footedness was 0.21 and 0.23, respectively, which is higher than the SNP-h2 reported in larger genetic studies using binary handedness measures. The heritability of the quantitative measure of handedness increased (0.45) compared to a binary measure for writing hand (0.27) in the Hong Kong twins. Genomic and behavioural SEM identified a shared genetic factor contributing to handedness, footedness, and eyedness, but no independent effects on individual phenotypes. Our analysis demonstrates how quantitative multidimensional laterality phenotypes are better suited to capture the underlying genetics than binary traits.

A reliable and valid tool for measuring visual recognition ability with musical notation.

Recognizing musical notation is an important skill to a full participation of Western classical music, but remains a largely under-researched topic in the psychology of music. One plausible reason of such omission is that, in the past, the research field has heavily relied on self-report of music reading ability, which was subjective and highly variable. This paper presents a reliable and valid tool for objectively measuring individual abilities in visual recognition of musical notation. The visual fluency task measures how fast one can accurately recognize a sequence of musical notation at a desired accuracy level using the adaptive psychometric method QUEST. We checked the reliability of this task in over 200 participants in terms of Guttman's λ-2 and Cronbach's alpha. Also, we evaluated the construct validity of this task by considering the convergent validity of this task with multiple external real-world measures of one's musical training background, with numerous experimental measures of visual tendencies of musical notation recognition and with sight-reading performance. Overall, the visual fluency task achieved satisfactory reliability and validity for measuring abilities in recognizing musical notation. This opens the door for characterizing the cognitive mechanisms, development, and individual differences in musical notation recognition, for understanding music learning and music psychology and for understanding of visual perceptual expertise in general.

Electroencephalography decoding of Chinese characters in primary school children and its prediction for word reading performance and development.

Research on what neural mechanisms facilitate word reading development in non-alphabetic scripts is relatively rare. The present study was among the first to adopt a multivariate pattern classification analysis to decode electroencephalographic signals recorded for primary school children (N = 236) while performing a Chinese character decision task. Chinese is an ideal script for studying the relationship between neural discriminability (i.e., decodability) of the orthography and behavioral word reading skills since the mapping from orthography to phonology is relatively arbitrary in Chinese. This was also among the first empirical attempts to examine the extent to which decoding performance can predict current and subsequent word reading skills using a longitudinal design. Results showed that neural activation patterns of real characters can be distinguished from activation patterns for pseudo-characters, non-characters, and random stroke combinations in both younger and older children. Topography of the transformed classifier weights revealed two distinct cognitive sub-processes underlying single character recognition, but temporal generalization analysis suggested common neural mechanisms between the distinct cognitive sub-processes. Suggestive evidence from correlational and hierarchical regression analyses showed that decoding performance, assessed on average 2 months before the year 2 behavioral testing, predicted both year 1 word reading performance and the development of word reading fluency over the year. Results demonstrate that decoding performance, one indicator of how the neural system is functionally organized in processing characters and character-like stimuli, can serve as a useful neural marker in predicting current word reading skills and the capacity to learn to read.

Multiple processing limitations underlie multitasking costs.

Human multitasking is typically defined as the practice of performing more than one task at the same time (dual task) or rapidly alternating between multiple tasks (task switching). The majority of research in multitasking has been focusing on individual paradigms, with surprisingly little effort in understanding their relationships. We adopted an individual-difference approach to reveal the limitations underlying multitasking costs measured in different paradigms. Exploratory factor analyses revealed not a general multitasking factor but instead three different processing limitations associated with response selection, retrieval and maintenance of task information, and task-set reconfiguration. The three factors were only weakly correlated with and thus not reducible to common measures of processing speed, working memory capacity and fluid intelligence. Males and females excelled in different aspects of multitasking, demonstrating the benefit of using a multifaceted view of multitasking competency in group comparison. Findings of the current study help resolve conflicting results between studies using different paradigms, and form the basis of more comprehensive measurement tools and training protocols covering different aspects of multitasking limitations. The study will also help future integration of multitasking abilities into the theoretical framework of executive function.

Is it impossible to acquire absolute pitch in adulthood?

Absolute pitch (AP) refers to the rare ability to name the pitch of a tone without external reference. It is widely believed to be only for the selected few with rare genetic makeup and early musical training during the critical period, and therefore acquiring AP in adulthood is impossible. Previous studies have not offered a strong test of the effect of training because of issues like small sample size and insufficient training. In three experiments, adults learned to name pitches in a computerized, gamified and personalized training protocol for 12 to 40 hours, with the number of pitches gradually increased from three to twelve. Across the three experiments, the training covered different octaves, timbre, and training environment (inside or outside laboratory). AP learning showed classic characteristics of perceptual learning, including generalization of learning dependent on the training stimuli, and sustained improvement for at least one to three months. 14% of the participants (6 out of 43) were able to name twelve pitches at 90% or above accuracy, comparable to that of 'AP possessors' as defined in the literature. Overall, AP continues to be learnable in adulthood, which challenges the view that AP development requires both rare genetic predisposition and learning within the critical period. The finding calls for reconsideration of the role of learning in the occurrence of AP, and pushes the field to pinpoint and explain the differences, if any, between the aspects of AP more trainable in adulthood and the aspects of AP that are potentially exclusive for the few exceptional AP possessors observed in the real world.

Beauty and the beast: Promotion concerns and the pursuit of physically attractive mates.

OBJECTIVE: In the mating market, individuals differ in their aspirations to pursue opposite-sex mates who have a relatively higher (vs. similar) level of physical attractiveness. Few studies have explored how motivational concerns outside the mating domain can account for these individual differences in romantic aspiration. Based on regulatory focus theory, this research tested how broad concerns for promotion and prevention influence the aspiration and dating outcome. METHOD: Four studies tested whether promotion concerns increase romantic aspiration and the chance to mate with a more physically attractive partner. The first three studies tested how promotion concerns, either measured (Studies 1a and 2) or manipulated (Study 1b), can influence romantic aspiration. Study 3 further tested how one's chronic promotion concerns are related to the physical attractiveness of the current partner (as rated by observers). RESULTS: The first three studies supported the prediction that promotion concerns increase aspiration to pursue more physically attractive mates. The last study also found that, controlling for their own physical attractiveness, individuals with stronger promotion concerns tend to mate with physically attractive partners. CONCLUSIONS: The results highlight the significant roles of broad motivational concerns in determining both aspiration and chance to date a more physically attractive partner.

Visual training with musical notes changes late but not early electrophysiological responses in the visual cortex.

Visual expertise with musical notation is unique. Fluent music readers show selectively higher activity to musical notes than to other visually similar patterns in both the retinotopic and higher-level visual areas and both very early (e.g., C1) and later (e.g., N170) visual event-related potential (ERP) components. This is different from domains such as face and letter perception, of which the neural expertise marker is typically found in the higher-level ventral visual areas and later (e.g., N170) ERP components. An intriguing question concerns whether the visual skills and neural selectivity observed in music-reading experts are a result of the effects of extensive visual experience with musical notation. The current study aimed to investigate the causal relationship between visual experience and its neural changes with musical notation. Novices with no formal musical training experience were trained to visually discriminate between note patterns in the laboratory for 10-26 hr such that their performance was comparable with fluent music readers. The N170 component became more selective for musical notes after training. Training was not, however, followed by changes in the earlier C1 component. The findings show that visual training is enough for causing changes in the responses of the higher-level visual areas to musical notation while the engagement of the early visual areas may involve additional nonvisual factors.

Sensitivity to configural information and expertise in visual word recognition.

Holistic processing has been regarded as a marker of perceptual expertise for many object categories. However, visual word processing, a common form of perceptual expertise in the population, is traditionally considered part-based instead of holistic, and whether it involves holistic processing remains inconclusive. In 4 experiments, we examined a well-known yet less studied indicator of holistic word processing-observers' sensitivity to changes in configural information of objects. A paradigm was designed with 2 crucial elements: specific requirement to process configural information within a word and an inversion manipulation. Experiments 1 and 2 showed that experienced observers were more sensitive to configural changes when words were presented in the familiar upright than unfamiliar inverted orientation. Of importance, such an inversion effect was correlated with one's fluency in word recognition in 1 of the conditions (nonnative Chinese readers viewing Chinese characters) where there was a larger variability in word recognition fluency. Experiments 3 and 4 compared sensitivity to configural and component changes in word processing, showing that expert readers were more sensitive to configural changes than component changes (defined as line thickness of parts) in words. The current findings suggest that, similar to face recognition and other domains of perceptual expertise, word recognition involves holistic processing. Instead of being a hallmark of face recognition, holistic processing is a general expertise marker shared by different domains of perceptual expertise. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Suppression of 12-Hz SSVEPs when viewing familiar faces: An electrophysiological index to detect recognition.

Criminal investigation often involves finding out what a suspect knows about people, such as victims and confederates, who are involved in the crime. This study explored the possibility of determining a person's recognition of other individuals by analyzing the steady-state visually evoked potentials (SSVEP) triggered by visual oscillations of familiar and unfamiliar faces. In our study, 23 adult (10 men) participants gave subjective familiarity ratings (in a 7-point Likert scale) of >300 celebrities' and strangers' faces. For each participant, ten familiar and ten unfamiliar faces were selected based on his/her ratings. The selected faces were presented at 6 Hz while the participants performed a color change detection task orthogonal to the attributes of faces. The task was designed to maintain participants' visual attention towards the faces throughout the stimulus oscillations. Any difference between conditions would indicate modulation of visual attention by face familiarity. Results showed that the 12-Hz event-related spectral perturbations (ERSPs in decibel) at parietal-occipital electrodes were significantly lower when viewing familiar faces compared to unfamiliar faces. In individual level analysis, 18 out of 23 (78%) participants had significantly lower 12-Hz ERSPs at left parietal-occipital ROI in familiar face than unfamiliar face trials. This is the first study to demonstrate that SSVEPs triggered by stimulus oscillations can reveal people's recognition of faces with only 20 trials per condition and 10-s for each trial.

Revisiting facial resemblance in couples.

It is widely believed that couples look alike. Consistently, previous research reported higher facial similarity for couples than non-couples, and that facial similarity predicts marital satisfaction. However, it is unclear if facial similarity in couples shown in previous studies was solely driven by extrinsic features like hairstyle, glasses, etc. Also unclear is what attributes are perceived as similar from the faces of a couple. In three experiments, we showed that faces were considered more similar in couples than non-couples even without extrinsic features. Personality and age perceived from faces were also more similar in couples. Importantly, by matching pairs of faces according to their perceived personality, we found that a higher similarity in the perceived personality of a face pair led to higher facial similarity and couple likelihood ratings. These findings suggest that, instead of a result of pure physical analyses, facial similarity in couples is partly based on active social cognitive judgments on perceived personality, which may reveal the actual personality of the couples and thus inform relationship quality.

Holistic processing as a hallmark of perceptual expertise for nonface categories including Chinese characters.

Holistic processing has been associated with perceptual expertise in different domains involving faces, cars, fingerprints, musical notes, English words, etc. Curiously Chinese characters are regarded as an exception, as indicated by reduced holistic processing found for experts with the Chinese writing system as compared with novices. We revisit the issue and examine one type of holistic processing, the obligatory attention to all parts of an object, using the composite paradigm from face perception literature. Chinese readers (experts) and non-Chinese readers (novices) matched the target halves of two characters while ignoring the irrelevant halves. We introduced differential response deadlines for experts and novices in order to match their performance level and to avoid ceiling performance for experts. Both experts and novices showed holistic processing, irrespective of the character structure (left-right or top-bottom) or presentation sequence (sequential or simultaneous matching). Experts' holistic processing also showed some sensitivity to the amount of experience with the characters, as it was larger for characters than noncharacters in some situations. Novices, however, did not show a systematic difference, suggesting that their effects were more related to their inefficient decomposition of a novel, complex pattern into parts. The current results, together with other recent findings of holistic processing for English words and musical notes, indicate that the development of holistic processing is not restricted to faces and objects. Instead it may be a general marker of expertise across a wider domain of visual discrimination than previously thought, including alphabetic and nonalphabetic writing systems.

Does media multitasking always hurt? A positive correlation between multitasking and multisensory integration.

Heavy media multitaskers have been found to perform poorly in certain cognitive tasks involving task switching, selective attention, and working memory. An account for this is that with a breadth-biased style of cognitive control, multitaskers tend to pay attention to various information available in the environment, without sufficient focus on the information most relevant to the task at hand. This cognitive style, however, may not cause a general deficit in all kinds of tasks. We tested the hypothesis that heavy media multitaskers would perform better in a multisensory integration task than would others, due to their extensive experience in integrating information from different modalities. Sixty-three participants filled out a questionnaire about their media usage and completed a visual search task with and without synchronous tones (pip-and-pop paradigm). It was found that a higher degree of media multitasking was correlated with better multisensory integration. The fact that heavy media multitaskers are not deficient in all kinds of cognitive tasks suggests that media multitasking does not always hurt.