A graphical user interface for infant ERP analysis

Recording of event-related potentials (ERPs) is one of the best-suited technologies for examining brain function in human infants. Yet the existing software packages are not optimized for the unique requirements of analyzing artifact-prone ERP data from infants. We developed a new graphical user interface that enables an efficient implementation of a two-stage approach to the analysis of infant ERPs. In the first stage, video records of infant behavior are synchronized with ERPs at the level of individual trials to reject epochs with noncompliant behavior and other artifacts. In the second stage, the interface calls MATLAB and EEGLAB (Delorme & Makeig, Journal of Neuroscience Methods 134(1):9–21, 2004) functions for further preprocessing of the ERP signal itself (i.e., filtering, artifact removal, interpolation, and rereferencing). Finally, methods are included for data visualization and analysis by using bootstrapped group averages. Analyses of simulated and real EEG data demonstrated that the proposed approach can be effectively used to establish task compliance, remove various types of artifacts, and perform representative visualizations and statistical comparisons of ERPs. The interface is available for download from http://www.uta.fi/med/icl/methods/eeg.html in a format that is widely applicable to ERP studies with special populations and open for further editing by users. Electronic supplementary material The online version of this article (doi:10.3758/s13428-013-0404-4) contains supplementary material, which is available to authorized users

Why do infants imitate selectively? Neural correlates of infants’ action understanding in the head-touch paradigm

Imitation is an important social learning mechanism for young infants exploring the world. Interestingly, infants do not imitate every action they observe – they rather do so selectively. Fourteen-month-olds predominantly imitated an unusual and inefficient action (turning on a lamp with one’s forehead) when the model’s hands were free compared to when the model’s hands were occupied (Gergely et al., 2002). Behavioral scientists have proposed contrasting explanatory accounts, differing with regard to the assumed level of infants’ cognitive abilities. Rational-imitation accounts suggest that infants selectively imitate unusual actions because they are surprised by the inefficiency of the action (Gergely & Csibra, 2003). In contrast, non-rational imitation accounts propose that selective imitation depends on more basic factors such as motor abilities (Paulus et al., 2011a,b). The integrative model by Zmyj and Buttelmann (2014) represents the first attempt to put together these opposing theories. Both accounts may operate on different processing levels. Bottom-up processes are related to non-rational imitation accounts, whereas top-down processing is based on the assumptions of the rational-imitation accounts. Despite the large body of behavioral research on selective imitation, the question of what are the neural mechanisms underlying these processes remains unanswered. In my dissertation, I aimed to uncover the underlying cognitive processes during the observation of head-touch actions by recording infants’ neurophysiological responses in three empirical studies. To test the assumptions of the top-down processes linked to the rational-imitation accounts, I examined neural markers associated with violation of expectation (VOE) in an adaptation of the head-touch paradigm. Overall, results suggest that 12- to 14-month-old infants, but not 9-month-old infants, display VOE when observing a person performing an inefficient head touch. This VOE response is context-dependent and is elicited when the model’s hands are free but not when the hands are restrained. In Study 1, VOE has been linked to a reduction in mu power in response to the unexpected head touch. In Study 2, this finding was extended such that when 12- to 14-month-old infants observed an unexpected head touch, their brains responded with increased attentional engagement (enhanced Nc amplitude) and a detection of a semantic violation (N400 component). Finally, in Study 3, in the absence of contextual information, 1-year-olds discriminated between hand- and head-touch outcomes on the Nc component only. Thus, infants require information of the action context to detect semantic violations within the head-touch paradigm. To conclude, the studies presented in my dissertation have paved the way to further our understanding of infants’ action perception and observational learning. Understanding the neural mechanisms of infants’ action perception in more depth, will help us to adequately foster the ideal observational learning conditions of novel actions. The results of this dissertation suggest that presenting infants with surprising action means puts them in an optimal receptive state for knowledge acquisition

An EEG study on emotional intelligence and advertising message effectiveness

Some electroencephalography (EEG) studies have investigated emotional intelligence (EI), but none have examined the relationships between EI and commercial advertising messages and related consumer behaviors. This study combines brain (EEG) techniques with an EI psychometric to explore the brain responses associated with a range of advertisements. A group of 45 participants (23females, 22males) had their EEG recorded while watching a series of advertisements selected from various marketing categories such as community interests, celebrities, food/drink, and social issues. Participants were also categorized as high or low in emotional intelligence (n = 34). The EEG data analysis was centered on rating decision-making in order to measure brain responses associated with advertising information processing for both groups. The findings suggest that participants with high and low emotional intelligence (EI) were attentive to different types of advertising messages. The two EI groups demonstrated preferences for “people” or “object,” related advertising information. This suggests that differences in consumer perception and emotions may suggest why certain advertising material or marketing strategies are effective or not

Selective Attention and Audiovisual Integration: Is Attending to Both Modalities a Prerequisite for Early Integration?

Interactions between multisensory integration and attention were studied using a combined audiovisual streaming design and a rapid serial visual presentation paradigm. Event-related potentials (ERPs) following audiovisual objects (AV) were compared with the sum of the ERPs following auditory (A) and visual objects (V). Integration processes were expressed as the difference between these AV and (A + V) responses and were studied while attention was directed to one or both modalities or directed elsewhere. Results show that multisensory integration effects depend on the multisensory objects being fully attended—that is, when both the visual and auditory senses were attended. In this condition, a superadditive audiovisual integration effect was observed on the P50 component. When unattended, this effect was reversed; the P50 components of multisensory ERPs were smaller than the unisensory sum. Additionally, we found an enhanced late frontal negativity when subjects attended the visual component of a multisensory object. This effect, bearing a strong resemblance to the auditory processing negativity, appeared to reflect late attention-related processing that had spread to encompass the auditory component of the multisensory object. In conclusion, our results shed new light on how the brain processes multisensory auditory and visual information, including how attention modulates multisensory integration processes

EEG theta and Mu oscillations during perception of human and robot actions.

The perception of others' actions supports important skills such as communication, intention understanding, and empathy. Are mechanisms of action processing in the human brain specifically tuned to process biological agents? Humanoid robots can perform recognizable actions, but can look and move differently from humans, and as such, can be used in experiments to address such questions. Here, we recorded EEG as participants viewed actions performed by three agents. In the Human condition, the agent had biological appearance and motion. The other two conditions featured a state-of-the-art robot in two different appearances: Android, which had biological appearance but mechanical motion, and Robot, which had mechanical appearance and motion. We explored whether sensorimotor mu (8-13 Hz) and frontal theta (4-8 Hz) activity exhibited selectivity for biological entities, in particular for whether the visual appearance and/or the motion of the observed agent was biological. Sensorimotor mu suppression has been linked to the motor simulation aspect of action processing (and the human mirror neuron system, MNS), and frontal theta to semantic and memory-related aspects. For all three agents, action observation induced significant attenuation in the power of mu oscillations, with no difference between agents. Thus, mu suppression, considered an index of MNS activity, does not appear to be selective for biological agents. Observation of the Robot resulted in greater frontal theta activity compared to the Android and the Human, whereas the latter two did not differ from each other. Frontal theta thus appears to be sensitive to visual appearance, suggesting agents that are not sufficiently biological in appearance may result in greater memory processing demands for the observer. Studies combining robotics and neuroscience such as this one can allow us to explore neural basis of action processing on the one hand, and inform the design of social robots on the other