Neural correlates of action observation and execution in 14-month-old infants: an event-related EEG desynchronization study

There is increasing interest in neurobiological methods for investigating the shared representation of action perception and production in early development. We explored the extent and regional specificity of EEG desynchronization in the infant alpha frequency range (6-9 Hz) during action observation and execution in 14-month-old infants. Desynchronization during execution was restricted to central electrode sites, while action observation was associated with a broader desynchronization across frontal, central, and parietal regions. The finding of regional specificity in the overlap between EEG responses to action execution and observation suggests that the rhythm seen in the 6-9 Hz range over central sites in infancy shares certain properties with the adult mu rhythm. The magnitude of EEG desynchronization to action perception and production appears to be smaller for infants than for adults and older children, suggesting developmental change in this measure.     

14 challenges and their solutions for conducting social neuroscience and longitudinal EEG research with infants

The use of electroencephalography (EEG) to study infant brain development is a growing trend. In addition to classical longitudinal designs that study the development of neural, cognitive and behavioural functions, new areas of EEG application are emerging, such as novel social neuroscience paradigms using dual infant-adult EEG recordings. However, most of the experimental designs, analysis methods, as well as EEG hardware were originally developed for single-person adult research. When applied to study infant development, adult-based solutions often pose unique problems that may go unrecognised. Here, we identify 14 challenges that infant EEG researchers may encounter when designing new experiments, collecting data, and conducting data analysis. Challenges related to the experimental design are: (1) small sample size and data attrition, and (2) varying arousal in younger infants. Challenges related to data acquisition are: (3) determining the optimal location for reference and ground electrodes, (4) control of impedance when testing with the high-density sponge electrode nets, (5) poor fit of standard EEG caps to the varying infant head shapes, and (6) ensuring a high degree of temporal synchronisation between amplifiers and recording devices during dual-EEG acquisition. Challenges related to the analysis of longitudinal and social neuroscience datasets are: (7) developmental changes in head anatomy, (8) prevalence and diversity of infant myogenic artefacts, (9) a lack of stereotypical topography of eye movements needed for the ICA-based data cleaning, (10) and relatively high inter-individual variability of EEG responses in younger cohorts. Additional challenges for the analysis of dual EEG data are: (11) developmental shifts in canonical EEG rhythms and difficulties in differentiating true inter-personal synchrony from spurious synchrony due to (12) common intrinsic properties of the signal and (13) shared external perturbation. Finally, (14) there is a lack of test-retest reliability studies of infant EEG. We describe each of these challenges and suggest possible solutions. While we focus specifically on the social neuroscience and longitudinal research, many of the issues we raise are relevant for all fields of infant EEG research.     

EEG mu rhythm and imitation impairments in individuals with autism spectrum disorder

Imitation ability has consistently been shown to be impaired in individuals with autism. A dysfunctional execution/observation matching system has been proposed to account for this impairment. The EEG mu rhythm is believed to reflect an underlying execution/observation matching system. This study investigated evidence of differential mu rhythm attenuation during the observation, execution, and imitation of movements and examined its relation to behaviorally assessed imitation abilities. Fourteen high-functioning adults with autism spectrum disorder (ASD) and 15 IQ- and age-matched typical adults participated. On the behavioral imitation task, adults with ASD demonstrated significantly poorer performance compared to typical adults in all domains of imitation ability. On the EEG task, both groups demonstrated significant attenuation of the mu rhythm when executing an action. However, when observing movement, the individuals with ASD showed significantly reduced attenuation of the mu wave. Behaviorally assessed imitation skills were correlated with degree of mu wave attenuation during observation of movement. These findings suggest that there is execution/observation matching system dysfunction in individuals with autism and that this matching system is related to degree of impairment in imitation abilities.     

Understanding action language modulates oscillatory mu and beta rhythms in the same way as observing actions

The mu rhythms (8–13 Hz) and the beta rhythms (15 up to 30 Hz) of the EEG are observed in the central electrodes (C3, Cz and C4) in resting states, and become suppressed when participants perform a manual action or when they observe another’s action. This has led researchers to consider that these rhythms are electrophysiological markers of the motor neuron activity in humans. This study tested whether the comprehension of action language, unlike abstract language, modulates mu and low beta rhythms (15–20 Hz) in a similar way as the observation of real actions. The log-ratios were calculated for each oscillatory band between each condition and baseline resting periods. The results indicated that both action language and action videos caused mu and beta suppression (negative log-ratios), whereas abstract language did not, confirming the hypothesis that understanding action language activates motor networks in the brain. In other words, the resonance of motor areas associated with action language is compatible with the embodiment approach to linguistic meaning.     

Using mu rhythm desynchronization to measure mirror neuron activity in infants

The Mirror Neuron System hypothesis stating that observed actions are projected onto the observer’s own action system assigns an important role to development, because only actions mastered by the observer can be mirrored. The purpose of the present study was to investigate whether there is evidence of a functioning mirror neuron system (MNS) in 8-month-old infants. High-density EEG was used to assess the mu rhythm desynchronization in an action observation task where the infants observed a live model. To reduce noise, ICA decompositions were used. The results show a higher desynchronization of the mu rhythm when infants observed a goal-directed action than when they observed a spatially similar non-goal-directed movement. The localizations of the sources are in agreement with those proposed by the MNS hypothesis. This indicates that the MNS is functioning at this age.     

Anticipation across modalities in children and adults: Relating anticipatory alpha rhythm lateralization,reaction time,and executive function

The development of the ability to anticipate—as manifested by preparatory actions and neural activation related to the expectation of an upcoming stimulus—may play a key role in the ontogeny of cognitive skills more broadly. This preregistered study examined anticipatory brain potentials and behavioral responses (reaction time; RT) to anticipated target stimuli in relation to individual differences in the ability to use goals to direct action (as indexed by measures of executive function; EF). A cross-sectional investigation was conducted in 40 adults (aged 18–25 years) and 40 children (aged 6–8 years) to examine the association of changes in the amplitude of modality-specific alpha-range rhythms in the electroencephalogram (EEG) during anticipation of lateralized visual, tactile, or auditory stimuli with inter- and intraindividual variation in RT and EF. Children and adults exhibited contralateral anticipatory reductions in the mu rhythm and the visual alpha rhythm for tactile and visual anticipation, respectively, indicating modality and spatially specific attention allocation. Variability in within-subject anticipatory alpha lateralization (the difference between contralateral and ipsilateral alpha power) was related to single-trial RT. This relation was more prominent in adults than in children, and was not apparent for auditory stimuli. Multilevel models indicated that interindividual differences in anticipatory mu rhythm lateralization contributed to the significant association with variability in EF, but this was not the case for visual or auditory alpha rhythms. Exploratory microstate analyses were undertaken to cluster global field power (GFP) into a distribution-free temporal analysis examining developmental differences across samples and in relation to RT and EF. Anticipation is suggested as a developmental bridge construct connecting neuroscience, behavior, and cognition, with anticipatory EEG oscillations being discussed as quantifiable and potentially malleable indicators of stimulus prediction.     

EEG coherence,joint attention and language development in the second year

Recent research has raised the hypothesis that brain maturation processes may play an important role in the linkage between infant joint attention and language development. This hypothesis was examined using EEG, joint attention and parent report language measures in a longitudinal study of 29 infants assessed at 14, 18 and 24 months of age. The results indicated that both measures of joint attention and EEG coherence at 14 months were related to language development at 24 months. Furthermore, both EEG coherence measures and joint attention measures made contributions to multiple regression equations predicting individual differences in language development. Finally, coherence data from this study were consistent with Thatcher's (1994 ) theory of different patterns of neural integration and differentiation in the early maturation of the left and right hemispheres. The implications of these results for understanding the nature of the relations between joint attention and language development, as well as the utility of EEG coherence measures in developmental neuroscience are discussed.     

Friendship stability and change in childhood and adolescence

The objective of this review is to focus on a neglected aspect of children’s and adolescents’ friendships: the level of temporal stability. First, a rationale for examining stability as a distinct friendship dimension is presented. Next, the different levels of friendship experiences are distinguished. Friendship stability is also discussed across developmental periods. Factors affecting friendships stability and individual correlates associated with friendship stability are then covered. Finally, the methodological issues pertaining to the study of friendship stability are addressed. The authors conclude by emphasizing the importance of pursuing future research that aims to demonstrate the pertinence of the friendship stability construct as an individual difference variable. Further, on a methodological level, the assessment of stability needs to be based on longitudinal designs that include multiple measurement waves. Ultimately, such detailed analysis of stability will allow a better understanding of the dynamic processes by which friendships change over time and affect children’s and adolescents’ psychosocial development.     

“Cuts in Action”: A High‐Density EEG Study Investigating the Neural Correlates of Different Editing Techniques in Film

In spite of their striking differences with real‐life perception, films are perceived and understood without effort. Cognitive film theory attributes this to the system of continuity editing, a system of editing guidelines outlining the effect of different cuts and edits on spectators. A major principle in this framework is the 180° rule, a rule recommendation that, to avoid spectators’ attention to the editing, two edited shots of the same event or action should not be filmed from angles differing in a way that expectations of spatial continuity are strongly violated. In the present study, we used high‐density EEG to explore the neural underpinnings of this rule. In particular, our analysis shows that cuts and edits in general elicit early ERP component indicating the registration of syntactic violations as known from language, music, and action processing. However, continuity edits and cuts‐across the line differ from each other regarding later components likely to be indicating the differences in spatial remapping as well as in the degree of conscious awareness of one's own perception. Interestingly, a time–frequency analysis of the occipital alpha rhythm did not support the hypothesis that such differences in processing routes are mainly linked to visual attention. On the contrary, our study found specific modulations of the central mu rhythm ERD as an indicator of sensorimotor activity, suggesting that sensorimotor networks might play an important role. We think that these findings shed new light on current discussions about the role of attention and embodied perception in film perception and should be considered when explaining spectators’ different experience of different kinds of cuts.     

The EEG and intelligence: An appraisal of methods and theories

Formerly, attempts were made to discover some relationship between intelligence differences and measures of “spontaneous” EEG activity. More recently the focus of interest has shifted to a putative relationship between intelligence differences and differences in EEG responses evoked by sensory stimulation. This article identifies serious conceptual and methodological problems of the EEG-intelligence literature which render some EEG-intelligence theories untenable. It is concluded that the “cerebral arousability” theory of EEG-intelligence relations is the only one that can account for the physical, neurological and psychological facts while addressing the main issues that have dominated the whole field of intelligence research for the past 100 years.     

Event-related Desynchronization of Mu Rhythms During Concentric and Eccentric Contractions

The purpose of this study was to compare the electroencephalographic (EEG) patterns and reaction times (RTs) of muscle activation between concentric and eccentric biceps brachii contractions under the RT paradigm and to evaluate how the EEG patterns and RTs changed with practice. Sixteen subjects performed 3 sets of 30 repetitions of submaximal voluntary concentric and eccentric biceps contractions. RT, event-related desynchronization (ERD) patterns of mu rhythm onset, and ERD amplitudes were selectively analyzed. Mental demand decreased as familiarity with the motor action increased due to practice regardless of contraction type. However, the 2 types of muscle contractions still have differences in brain activity regardless of decreased mental demand: eccentric contractions require earlier preparation than concentric contractions.     

Delta and spindle components in the integrated EEG during nocturnal sleep for infants with developmental disabilities

The delta and spindle components in the integrated EEG for 121 infants with developmental disabilities (from 4 mo. to 6 yr. of age: M=1.79, SD=0.14; 57 girls and 64 boys) were studied throughout nocturnal sleep. In 80 (66.1%, Group A) of 121 subjects, periodic changes of delta and spindle rhythm powers were noted in measurements of EEG made during sleep. In 28 (23.1%, Group B), delta but not spindle rhythm powers were found, and in the remaining 13 subjects (10.7%, Group C) neither delta nor spindle rhythm powers were found throughout measurements of EEG made during sleep. The Tsumori-Inage Questionnaire for Infants was administered to the parents to estimate subjects' behavioral developmental level as Developmental Quotients. Significantly lower mean Developmental Quotients were found for Groups B and C than Group A. These findings suggested that the presence or absence of delta and spindle rhythm powers in EEG measurements made during nocturnal sleep could be taken as an index of the severity of developmental disorders in infants with developmental disabilities.     

Going where the action is to conceptualize the person

Contemporary psychology is highly structured in terms of conventional and traditional methodological practices, including fragmenting, objectifying, and aggregating. Such practices sometimes impede understanding and investigating the person in terms of what he/she does as an integrated active individual who develops. The goal of this paper is to outline a systems conceptualization of the person as a developing individual who acts in relation to others in cultural practices. Such action is conceptualized as emerging through multiple and interrelated individual, social, and cultural processes, as well as in terms of multiple and interrelated domains of functioning that develop. This conceptualization is applicable to a wide range of issues in psychology as a whole. Moreover, starting with an overall conceptualization of action provides ways to overcome some limitations of conventional practices, and also provides a basis for conducting systematic and integrative research on the person.     

Using EEG to Study Cognitive Development: Issues and Practices

Developmental research is enhanced by use of multiple methodologies for examining psychological processes. The electroencephalogram (EEG) is an efficient and relatively inexpensive method for the study of developmental changes in brain–behavior relations. In this review, we highlight some of the challenges for using EEG in cognitive development research. We also list best practices for incorporating this methodology into the study of early cognitive processes. Consideration of these issues is critical for making an informed decision regarding implementation of EEG methodology.     

Is There Room for ‘Development’ in Developmental Models of Information Processing Biases to Threat in Children and Adolescents?

Clinical and experimental theories assume that processing biases in attention and interpretation are a causal mechanism through which anxiety develops. Despite growing evidence that these processing biases are present in children and, therefore, develop long before adulthood, these theories ignore the potential role of child development. This review attempts to place information processing biases within a theoretical developmental framework. We consider whether child development has no impact on information processing biases to threat (integral bias model), or whether child development influences information processing biases and if so whether it does so by moderating the expression of an existing bias (moderation model) or by affecting the acquisition of a bias (acquisition model). We examine the extent to which these models fit with existing theory and research evidence and outline some methodological issues that need to be considered when drawing conclusions about the potential role of child development in the information processing of threat stimuli. Finally, we speculate about the developmental processes that might be important to consider in future research.     

人类镜像系统参与音乐情绪的自动加工：来自EEG的证据

大脑中线电极诱发的μ抑制波(包括α和β频段)是人类镜像系统活动的电生理指标。尽管音乐情绪表现被认为是通过模仿个体的心理状态来实现的, 但是尚未有研究探讨人类镜像系统与音乐情绪加工的关系。本研究通过EEG技术, 采用跨通道情绪启动范式, 探究人类镜像系统是否参与和弦情绪的自动加工。愉悦或不愉悦的和弦启动情绪一致与不一致的目标面孔。行为结果显示, 被试对情绪一致面孔的反应显著快于情绪不一致面孔的反应。EEG结果显示, 在听觉刺激出现后的500~650 ms之间, 与情绪一致条件相比, 情绪不一致条件诱发了β频段的去同步化。在听觉刺激出现后的300~450 ms, 无论是情绪一致, 还是不一致条件, 都诱发了α频段的去同步化。源分析结果显示, μ抑制波主要出现在人类镜像系统的相关脑区。这些结果表明, 音乐情绪的自动加工与人类镜像系统的活动密切相关。     

A Piagetian approach to infant referential behaviors

Near the end of the first year of life, infants begin producing referential behaviors that in adults indicate joint attention, or coordinating shared attention to an object with another person. These behaviors have been interpreted in the social cognitive literature as an indication that infants realize they are sharing attention to an object with another person. In this paper, we address theory and research on infant referential behaviors described as joint attention and offer an alternative explanation for the presence of these behaviors. Using Piaget's constructivist theory, we show how research in this area can be interpreted without assuming that infants have advanced social cognitive abilities. We argue that infants’ referential behaviors are motor signifiers of thought and that infants recognize humans as particularly relevant objects for their goal-directed behaviors. Finally, we describe how the field of infant joint attention research should proceed if a comprehensive understanding of infant cognitive processes is to be desired.     

Neighborhood Contextual Factors and Early-Starting Antisocial Pathways

This paper examines research investigating the effects of neighborhood context on the onset and persistence of early-starting antisocial pathways across middle and late childhood. The review begins by presenting theory and research mapping the early-starting developmental pathway. Next, sociologically and psychologically based investigations linking neighborhood context and early antisocial behavior are examined, in order to posit and evaluate the effects of community economic disadvantage, exposure to neighborhood violence, and involvement with neighborhood-based deviant peer groups on the development of antisocial behavior. It is suggested that middle childhood may represent a critical developmental period during which children are at heightened risk for neighborhood-based effects on antisocial behavior problems. Key methodological issues are addressed, and recommendations for future research integrating developmental pathways and neighborhood theory and research are advanced.     

Action mechanisms for social cognition: behavioral and neural correlates of developing Theory of Mind

Many psychological theories posit foundational links between two fundamental constructs: (1) our ability to produce, perceive, and represent action; and (2) our ability to understand the meaning and motivation behind the action (i.e. Theory of Mind; ToM). This position is contentious, however, and long‐standing competing theories of social‐cognitive development debate roles for basic action‐processing in ToM. Developmental research is key to investigating these hypotheses, but whether individual differences in neural and behavioral measures of motor action relate to social‐cognitive development is unknown. We examined 3‐ to 5‐year‐old children's (N = 26) EEG mu‐desynchronization during production of object‐directed action, and explored associations between mu‐desynchronization and children's behavioral motor skills, behavioral action‐representation abilities, and behavioral ToM. For children with high (but not low) mu‐desynchronization, motor skill related to action‐representation abilities, and action‐representation mediated relations between motor skill and ToM. Results demonstrate novel foundational links between action‐processing and ToM, suggesting that basic motor action may be a key mechanism for social‐cognitive development, thus shedding light on the origins and emergence of higher social cognition.