RU2794620C2 - Device for assessing emotions in infants and young children - Google Patents

Abstract

FIELD: physiological psychology.

SUBSTANCE: invention relates to portable electroencephalographic (EEG) headsets for the studies of the cognitive and emotional development of infants and young children. The device comprises EEG electrodes configured to provide optimal point contact with the scalp of an infant or young child, which are positioned according to option A or B. In case of option A, pairs of electrodes are placed to provide symmetrical recording in the frontal, temporal, and parietal areas. Six electrodes are placed at the anterior pole to assess EEG asymmetry in an infant or young child. Two electrodes are placed in the temporal region to study pleasant/unpleasant sensations in the auditory zone. Three electrodes are placed in the parietal region to study the attraction of attention to emotional speech and somatosensory activity. In the case of option B, the pairs of electrodes are placed so as to ensure symmetrical recording in the frontal, temporal, and parietal regions. Six electrodes are placed at the anterior pole to assess EEG asymmetry in an infant or young child. Two electrodes are placed in the temporal region to study pleasant/unpleasant sensations in the auditory zone. Five electrodes are placed in the parietal region to study the attraction of attention to emotional speech and somatosensory activity. Four electrodes are placed in the occipital region to measure visual processing of emotions.

EFFECT: more accurate measurement and monitoring of the attention and engagement of infants and young children is achieved.

6 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The present disclosure relates to portable electroencephalographic (EEG) headsets for use in studies of the cognitive and emotional development of infants and young children.

DESCRIPTION OF THE PRIOR ART

The development of emotions is an important condition for the optimal growth of cognitive functions in infants. This maturation process is based on the formation and synchronization of brain networks that will ultimately determine cognitive function. Electroencephalography (EEG) is a suitable technique for studying the cognitive and emotional correlates of brain activity. However, the use of this technique in infants is limited by a number of practical and developmental factors compared to EEG studies in adults. Age and EEG pattern stability may play an important role in validating infant data collection and functional interpretation of underlying brain processes. There are technical and procedural difficulties in conducting EEG studies of the emotional development of infants.

Traditional electroencephalographic (EEG) systems use electrodes on the scalp, usually attached to elastic caps or bands, to monitor neurological activity. To improve sensitivity, electrically conductive gels and pastes are applied to the scalp before placing the electrodes. However, the application of electrically conductive gels and pastes to infants and young children is often inconvenient, time consuming and undesirable.

Work has been carried out to develop more portable, efficient and effective EEG data collection mechanisms.

US Pat. Nos. 9,336,535 and 8,655,428 to Nielsen disclose neural response data acquisition systems that include a headset for collecting first neuronal response data and second neuronal response data from a user when the user is exposed to a stimulus material, the headset including a tape, a first sensor and a second sensor extending from the belt, the first sensor and the second sensor being rotatably mounted relative to the belt, and a processor. Elastic caps or bands may be uncomfortable for long-term use.

In the replacement US patent No. Re. 34,015 issued to Children's Medical Center Corporation describes a device for generating a topographical display of information about the electrical activity of the brain based on the responses of electrical activity transducers mounted on the head.

US Patent No. 9,770,184 issued to Bittium Bioisignals OY describes the attachment of an electrode configuration to hairless areas of a patient's head in order to obtain high quality measurement information.

US Pat. No. 9,370,313 and EP 3,087,918 A1 issued to Bio-signal Group Corp. describe a device for performing electroencephalography on a patient, which comprises a sagittal portion comprising: fixing shoulder; ii) a cervical latch comprising two arms, a first cervical latch arm and an opposite second cervical latch arm; iii) the middle part between the forehead brace and the neck brace; and iv) a plurality of embedded electrodes in the headband and midsection. The device further comprises: a coronal part containing a plurality of built-in electrodes; and electrical connectors for electrically connecting the built-in sagittal and coronal electrodes to the electroencephalograph.

French patent FR 2975276 B1 and WO 2012156643 A1 issued by the University de Picardie Jules Verne and the Center Hospitalier Universitaire d'Amiens describe a device for measuring brain activity signals of a subject, which contains a support structure (2) designed to hold sensors, which is different the fact that the support structure (2) forms a frame that has connecting elements (5) and cavities between said connecting elements, moreover, the connecting elements (5) form at least one central chain (50) and side chains (51), moreover, the side chains the chains (51) are located on each side of the central chain and have gaps between them and are connected by means of connecting elements (8), while the side chains (51) are hinged to the central chain (50) and preferably exhibit an articulated rotation around at least two axes of rotation.

In WO 2013124366 A1 and GB 2499595 A issued by James I.E. Roche describes an encephalographic electrode system for use in neonatal brain monitoring that comprises a deformable pad shaped and sized to fit an infant's head, the pad preferably forming four lobes, the system further comprising an electrode array arranged around the pad lobes and capable of providing electrical contact with the head when the substrate is placed on it.

US Pat. No. 7,415,305 and US 20060074336 A1 issued to The Trustees of Columbia University in the City of New York describe methods and systems for monitoring and evaluating brain electrical activity. This reference describes that the system comprises an EEG device for obtaining EEG information, the device comprising a plurality of electrodes placed to measure the electrical activity of a subject's brain; and a processing device for processing the EEG information to obtain data including local timing information, the processing device being configured to execute a computer algorithm for reducing residual volume conduction artifact in the received local timing information. "Local timing information" is defined as information that is a quantitative measure of local synchrony in which adjacent electrodes (or other means of obtaining a measure of electrical activity at a location) used in calculating this quantitative measure are spaced no more than 3 centimeters apart. . In some embodiments, local coherence is used as a measure of local synchronization.

WO 2007006976 A3 and FR 2888487 A1 issued by the University de Picardie Jules Veme and the Center Hospitalier Universitaire d'Amiens describe a head cap for measuring brain activity of a subject, containing means for measuring brain activity (3) and a surrounding element (2), which can be located on the human head. The source describes that the surrounding element (2) is completely or partially made of a material in the form of a deformable paste with a shape memory effect, which can be molded to the shape of the subject's head.

CN 103989473 B issued by Ying Xue describes a method for properly positioning electrodes on a person's head.

WO 2008058343 A1 issued by the University of Queensland describes a method for detecting a seizure in a newborn or young child.

U.S. Published Application No. 20040030258, filed by Tru-Test Limited, describes a flexible, conformable sensor assembly that includes an array of electrodes specifically designed to provide stable, long-term recording of EEG signals in a preterm or newborn infant in an intensive care unit. .

Grossman, T., The Development of Emotion Perception in Face and Voice During Infancy, Restorative Neurology and Neuroscience, Vol. 28 (2010): 219-236 provides a review of the literature on how the ability to interact with other people develops in infancy, and what brain processes underlie the perception of emotions of different modalities in infants. Grossman's publication describes a set of electrophysiological studies that provide insight into the brain processes that underlie developing abilities in infants.

The mechanisms available have various limitations. Therefore, it is desirable to provide improved EEG data collection mechanisms in infants and young children.

DISCLOSURE OF THE INVENTION

To solve this problem, the present invention proposes a device for studying the cognitive and emotional development of infants and young children, containing: electrodes for electroencephalography (EEG), designed to provide optimal point contacts with the scalp of an infant or young child, and the EEG electrodes arranged according to option A or B:

A) pairs of electrodes are placed to provide symmetrical recording in the frontal, temporal and parietal regions, with six electrodes placed in the frontal pole region to assess EEG asymmetry in an infant or young child, two electrodes are placed in the temporal region to study pleasant / unpleasant sensations in the auditory zone, and three electrodes are placed in the parietal region to study the attraction of attention to emotional speech and somatosensory activity;

B) pairs of electrodes are placed to provide symmetrical recording in the frontal, temporal and parietal regions, with six electrodes placed in the frontal pole region to assess EEG asymmetry in an infant or young child, two electrodes are placed in the temporal region to study pleasant / unpleasant sensations in the auditory zone, five electrodes were placed in the parietal region to study the attentional attraction to emotional speech and somatosensory activity, and four electrodes were placed in the occipital region to measure the visual processing of emotions.

In private embodiments, the implementation of the proposed device further comprises a flexible support structure attached to the electrodes; amplifiers coupled to the electrodes, the data from each of the electrodes being individually amplified and isolated. In particular, the amplifiers are made on a flexible printed circuit board. The amplifier preferably transmits the combined data wirelessly to a remote data analyzer. The amplified data can be combined with amplified data from other EEG headset electrodes.

The description will be best understood by reference to the following description in conjunction with the accompanying drawings, which illustrate specific embodiments.

BRIEF DESCRIPTION OF GRAPHICS

On FIG. 1A and 1B illustrate exemplary systems for performing data collection and functional interpretation of underlying brain processes in infants and young children.

On FIG. 2A and 2B illustrate examples of electrode configurations for optimal data acquisition.

On FIG. 3 illustrates examples of EEG characteristics that can be observed using a data acquisition system.

FIG. 4 illustrates one example of a methodology for performing data synchronization.

DETAILED DESCRIPTION OF SPECIFIC IMPLEMENTATION OPTIONS

From birth, babies develop and demonstrate the ability to experience and express different emotions. They express biologically basic emotions, such as pleasure when they are full or anxiety when attention is needed. Given the important role that emotions play in the overall functioning of the brain, research into the nature of infant emotions has attracted considerable interest in recent decades. Currently, this interest is focused on the basic brain patterns associated with emotional perception and development in infants.

Emotional expressions have been studied in a population of normal infants for decades, and it is noted that facial components of emotional expression are present very early after birth (Camras, Holland and Patterson, 1993; Calhoun and Kuczera, 1996; Izard & Malatesta, 1987; Phillips, Wellman and Spelke, 2002). If we consider facial expressions as external cues indicating an internal emotional state, then the next question is, do infants experience emotions in the same way as children or adults? It is known from various studies that infants are not aware of their own emotional states until the age of 2 years. Infants experience what is known as "dissociation between state and experience" (Lewis and Michalson; 1983; Reference literature). This means that babies have an emotion but do not experience an emotional state. The ability to experience one's own emotions depends on the development of a number of cognitive skills that do not emerge until the second year of life. One of these cognitive skills is what is known as “self-awareness” (also called “self-awareness”), and its emergence is a product of the maturation of brain structures (mainly the prefrontal cortex, limbic cortex, basal forebrain, amygdala, hypothalamus, and brainstem) that are constantly changing from birth and through the different stages of infancy, rather than by an automatic process. Thus, until infants reach this level of neurological development, the ability to experience any emotion as one's own conscious state is absent (see Lewis, 2003; 2011).

Thanks to recent advances in neuroimaging, we can further explore the neuronal mechanisms associated with early emotional states in terms of structure maturation and synapse formation. Studies using high spatial resolution techniques such as functional magnetic resonance imaging (fMRI) have largely documented the involvement of cortical and subcortical structures (eg, mainly the amygdala, anterior insula, medial prefrontal cortex) in processing specific emotions, such as fear or emotional connection, during the first year of life (Callaghan et al., 2014; Johnstone, 2006; Morgane et al., 2005). However, fMRI lacks the temporal resolution required to record ongoing neuronal functional changes associated with emotion processing (Banaschewski and Brandeis, 2007; Hajcak, Moser, & Simons, 2006). On the other hand, the EEG technique is particularly accurate for studying cognitive processes that occur in the millisecond range, given its high temporal resolution (de Haan, 2007; reference literature). This level of temporal accuracy is very important when studying monthly changes in brain connections and behavior (Cuevas and Bell, 2011). In addition, for measuring emotion-related activity in young children, EEG has many key advantages over other neuroimaging modalities. One of these advantages is that this method allows the collection of brain-related data in a relatively unrestricted experimental environment, comparable to normal infant behavior. Moreover, the use of high-density EEG allows for greater spatial resolution, which is very important when comparing cerebral hemispheres (eg, asymmetries) and scalp regions. In general, the advantage of the EEG method is that it is objective and not subject to observer scores.

The electroencephalogram (EEG) is a research method with a long history and a promising future in terms of improving the study of the emotional development of infants.

2. EEG measurement of emotion in young children (disaggregated by age)

Although there is significant progress in the study of infant emotions using EEG techniques (see recent publications in the journals: Gomez et al., 2016; Porto et al., 2016; Taylo-Colls and Pasco Fearon, 2015; Van den Boomen, Munsters and Kemmer , 2017), the data often appears to be fragmented and full of uncertainties related to the neuronal signatures underlying emotion processing in infants and young children. This lack of agreement is mainly based on the type of emotion measured (i.e., underlying or derived), age factor, and methodological aspects such as the relevant EEG study paradigms.

A common issue when performing an EEG study in infants relates to the correct identification of frequencies. According to studies, the normal predominant frequency bands in the EEG of an infant are 4-6 Hz and 6-9 Hz (Calkins, Fox and Marshall, 1996; Marshall, Bar-Haim and Fox, 2002). These are slow brain waves thought to indicate neuronal activation in infants (Allen, Coan and Nazarian, 2004; Davidson, 1988). However, in relation to the boundaries of frequency ranges, the data often turn out to be fragmentary and full of contradictions. This lack of agreement is mainly based on the type of emotion measured (i.e., underlying or derivative), age factor, and methodological issues such as a more relevant approach to EEG. In addition, the EEG of infants is sensitive to the recording context. This means that EEG changes are strongly influenced by the content of sensory input, stimulus significance (Davidson and Fox, 1982; Missana and Grossmann, 2015), observation of actions (Cuevas et al., 2014; Fox et al., 2016; Marshall and Meltzoff, 2011) and maternal psychological background, such as depression (Field et al., 1995; Jones et al., 1997; Lusby, Goodman, Bell and Newport, 2014).

Since the development of the brain is a dynamic system, one can expect the presence of unstable patterns of neuronal activity in different age periods. Indeed, early emotional stimulation has been shown to correlate with significant EEG changes in infants. According to a review of the literature, neuronal signatures for the development of positive emotions in the first year of life can be explored over two age periods. The following section provides an overview of recent EEG research into infant emotions during the first year of life based on age-related critical changes in brain activity. Moreover, we will discuss the pros and cons of the EEG methods that are currently being used to investigate emotion processing in infants in clinical and non-clinical populations.

Age Range: 0-6 months

Basic emotions

From a biological point of view, the emergence of emotional networks is a sequential process, since the development of certain emotions (fear, sadness, guilt, empathy, frustration, etc.) necessarily preceded other emotions (anxiety, comfort, interest). From birth (0-2 months), infants have an innate perception of facial expressions and emotionally colored voices. It is now known from neuroimaging studies that the neonatal brain can distinguish basic emotions by facial expressions such as joy and sadness (Johnson, Dziurawiec, Ellis, and Morton, 1991), or by voice with different emotional overtones (Cheng et al., 2012; Grossmann et al., 2005; Zhang et al., 2014). Namely, expression-related activity in the infant brain appears from about 2 months of age (de Heering et al., 2005, 2012), but is not necessarily associated with the recognition or processing of emotions, as occurs in adults. Pre-maturation of the limbic structures (the amygdala) is required, as well as the full development of the visual system in order to obtain an adult-like emotion processing system.

With the development of cortical areas of visual representation, the limited vision of the infant quickly develops into full-fledged binocular vision. According to the literature, early changes in the perception of faces are considered to be the foundation for the emotion processing network (Leppänen and Nelson, 2008), since biologically significant features are associated with human faces (for example, faces can express threat or well-being).

At the age of 3-6 months, the ability of infants to recognize emotions improves dramatically, along with a significant growth of limbic structures associated with identifying memory (ie, the hippocampus) and the development of key neuronal programs (ie, during a period of rapid growth). At this age, babies smile and laugh (smiling before this age is considered imitative, not emotional), showing excitement if they see or experience pleasurable events; they cry when upset, seek comfort, and are able to differentiate between adults based on how they look, talk, or feel.

The following section describes EEG characteristics in infants according to major milestones in neuronal development.

Major EEG changes during development

Between 0 and 5 months, it is important to identify typical EEG signatures and frequency band changes associated with infant emotional behavior. Various studies have elucidated how the EEG signal changes with different stages of development. For example, it is known that typical alpha oscillations (power spectrum from 7 to 15 Hz) are absent until the age of 10 months (Reference). Instead, infants show what is known as "alpha-like" activity in the posterior regions of the brain (range 8-13 Hz), reminiscent of the classic alpha rhythm seen in adults (Lindsley, 1938, 1939; Smith, 1938, 1941). Changes in these posterior rhythms can occur over short periods of time, shifting from 3–9 Hz at 1 week of age to 4–9 Hz. By 3 months of age, the main peak is around 5 Hz (Diego, Jones and Field, 2009).

In early development studies, lower theta EEG activity has been associated with cognitive and emotional processing in young infants (Futagi, et al., 1998; Kugler and Laub, 1971; Lehtonen et al., 2002; Paul, Dittrichova and Papousek, 1996). An increase in the power of the theta band in infants as they grow older is noted at the age of 3 to 6 months (Lehtonen et al., 2002; Stroganova and Orehova, 2007). In some of these studies, theta activity has been associated with early infant expression of positive and negative emotions such as comfort or sleepiness (Futagi et al., 1998). The specific range of theta frequencies that reflect the emergence of such emotional states is subject to changes caused by neuronal developmental events. For example, it is known that the theta frequency range in infants, used as a reference, is approximately 36 Hz, but these limits do not coincide in all studies, which makes it difficult to accurately interpret the functional significance of the EEG spectra. Thus, in light of the observed individual variability in EEG frequency bands in infants, the assignment of frequency intervals to specific oscillations can sometimes be misleading, hence age adjustment calibration should not be arbitrary.

EEG studies and methods

The most prominent signal of early emotional processing in infants is their inherent receptivity to human faces. Reviewed data indicate that some degree of facial processing begins to appear in infants at about 2 months of age (Easterbrook, Kisilevsky, Muir and Laplante, 1999; Walton & Bower, 1993). Indeed, neuroimaging data show that subcortical structures, such as the amygdala, are functional from birth, thus playing a critical role in newborns' early tendency to pay attention to faces (Johnson, 2005; Leppänen and Nelson 2009). However, the development of more advanced skills for recognizing facial expressions occurs with the acquisition of more experience in social contacts (Le Grand, Mondloch, Maurer and Brent, 2001; Pascalis et al., 2005)

With regard to neuronal correlates of processing faces and emotions, studies of event-related potentials (ERP) show a change in the pattern of neuronal activity in response to the display of faces compared to objects other than faces in infants as young as 3 months of age (Halit, et al., 2003 ; 2004). However, unlike adults, the same facial processing mechanisms appear to be activated in the infant when presented with a wider range of other stimuli (i.e., objects, animals), suggesting that the underlying networks become more specialized in relation to human faces in development (Halit et al., 2003).

In newborns, it is quite difficult to accurately determine the level of attentional involvement in relation to emotionally evoking visual cues, such as faces, because the patterns of attentional networks are still immature. In addition, the ability to recognize different types of facial expressions is not available until the age of 5-7 months. On the contrary, the auditory system is much more developed at birth than the visual system and may provide better EEG performance in distinguishing emotions (Carral et al., 2005; Gottlieb, 1971; Haden et al., 2009; Trehub, 2003; Ruusuvirta et al. ., 2003). Thus, to study the perception of emotions in infants in the first months of life, instead of using visual stimuli such as facial expressions, it is more convenient to use a multimodal approach. For example, you can use the synchronization of facial and vocal stimuli to measure the discrimination of emotions.

In light of the above, in infants during the first months of life, it is appropriate to study EEG-related emotion processing activity using classical auditory experimental designs. Mismatch negativity (MMN) is particularly well suited to neonates as it can be induced in the absence of attention (Nätänen et al., 1993; 2007; Luck, 2005). In addition, to measure the neuronal response of newborns to an emotional voice, a modified auditory exclusion scheme is usually used. In this regard, there are few studies that have identified neuronal correlates of emotional voice processing in newborns using appropriate schemas, also combined with an ERP approach (Cheng et al., 2012; Zhang et al., 2014). In one of these studies, emotional voices expressing fear and anger were shown to elicit a different pattern of neuronal correlates in newborns (for example, a response mismatch approximately 150–250 ms after a stimulus) (Zhang et al., 2014). The authors concluded that in the early stages, the brain may have different neuronal mechanisms for processing the vocal expression of fear and anger, although they agree that such early discrimination cannot be explained by the emotional experience of fear or anger in newborns. More likely, it can be interpreted as a previous neuronal contribution to the further development of emotions.

Discussion

One of the main questions in the study of the neuronal basis of emotion in infants (mainly before the age of 6 months) relates to what specific emotions can be studied with minimal certainty. Often researchers focus on observable signs of emotional expression when interpreting infant emotions. Although decoding facial and body expressions provides information about recognizable emotions, researchers have differing opinions about the range of emotions that infants can experience (see Camras, 2004). In general, the emotional state of newborns is defined as a continuum of mood swings from anxious to comfortable and vice versa, and is largely influenced by caregivers' own states (i.e. infants become irritable when the mother is irritable). However, studies are ongoing on the neuronal correlates of early fear or anger in normal infants (Cheng et al., 2012; Zhang et al., 2014), and the results are not conclusive. Indeed, consistent evidence shows that attention to threatening stimuli appears at 6–7 months of age, which corresponds to the developmental period when fear appears (Leppänen and Nelson, 2012). Thus, spontaneous facial reactions of fear and anger in newborns may reflect the emergence of neural circuitry for processing more advanced emotional stimuli with social-emotional significance, but do not indicate actual experience of anger or fear. In addition, we found that it is not enough to analyze the emotional states of newborns based on correlates such as facial expressions, given that infants at this age have a high ability to imitate adults (Hue, 2011; Isomura and Nakano, 2016; Oostenbroek et al., 2016 ). The best way to study infants' emotional experience (i.e., anger, comfort, pleasure) using EEG may be to induce situations of interruption or intensification of important actions, such as sucking, feeding, or audiovisual situations (i.e., target-blocking circuitry; Lewis et al. ., 1992).

We also found that a significant amount of EEG research has focused on an emotionally meaningful approach that focuses on neonates experiencing primary emotions such as pleasure or anxiety. In general, these emotions of early life are studied based on differences in the right and left frontal cortex in response to various factors that cause positive/negative emotions (Davidson and Fox, 1982; Fox and Davidson, 1986; Fox and Davidson, 1987) . This assumption comes from a model of EEG asymmetry in which activation of the frontal left cortex is associated with positive emotions, and activation of the frontal right cortex is associated with negative emotions (Davidson, 1993, 2004; Coan and Allen, 2003). Such differential lateralization in infants has been reported in a limited number of studies, although findings can be interpreted based on different stimulation conditions (i.e., novel or familiar stimuli), and it is sometimes difficult to determine whether these frontal asymmetries reflect emotion processing activity or changes. associated with perception. Thus, researchers should keep in mind that the measurement of frontal EEG asymmetry in infants in the first months of life is often accompanied by a high level of error or inaccuracy due to the factor of neuronal development and the lack of pronounced functional significance of frontal EEG asymmetry at this age.

Finally, not only is it suggested that frontal EEG asymmetries are associated with early emotional response, but they are also thought to reflect an underlying developmental mechanism of individual emotional regulation (Fox, 1994). Thus, such early markers of frontal asymmetries are important prerequisites for understanding individual differences in emotional behavior.

6-12 months: Switching neuronal development

Basic emotions

A more general question in the field of emotion research is whether specific emotions, such as anger or happiness, can be identified based on a specific pattern of brain activity. In infants, this issue is of increasing interest, given that neuronal response can serve as a marker of early development and predict infants' future socio-emotional skills (Fox et al., 1995; Harmon-Jones et al., 2010: Paulus et al., 2013; Tomarken et al., 1992; Reid et al., 1998).

As the brain develops, more developed emotions appear in response to longer-term stimulation from the environment. By the age of 6 months or more, other observable facial expressions appear (laughter, displeasure, fear, etc.), accompanied by a sequence of body movements (waves of arms, legs), indicating states of surprise, interest, joy, anger, fear and discontent ( Lewis, 2007). Some of these emotions (ie, fear, surprise) may reflect underlying cognitive processes such as perceptual discrimination, short-term memory, or development of socialization. For example, consistent data show that attention to a fearful face (appearing around 6–7 months of age) correlates with other neuronal responses than attention to a happy face (Jessen and Grossmann, 2015). This distinction does not occur in younger infants who pay more attention to smiling faces, indicating an increase in the cortical response after 6 months of age (Bayet, Quinn, et al., 2015; Jessen and Grossmann, 2014, 2015; Leppänen and Nelson, 2009, 2012; Yrttiaho et al., 2014). Between the ages of 5 and 6 months, babies begin to show fear of strangers and show visible signs of discomfort or anxiety.

Toward the end of the first year of life, babies become very emotional, moving quickly from absolute happiness to absolute frustration or anger. They also begin to understand other people's emotions, demonstrating a finer understanding of emotional communication cues, such as giving an expected smile, as well as managing contextual emotional cues when perceiving facial expressions (Venezia, Messinger, Thorp and Mundy, 2004). At approximately 12 months of age, infants begin to make connections between facial expressions and specific emotions, thus demonstrating a rudimentary awareness of their own emotional states.

Main EEG changes

In general, changes in EEG spectral power due to neuronal development are expected, with a relative decrease in low-frequency rhythms (i.e., 0.5-4 Hz delta waves). By the age of 6 months, in response to various emotional triggers and behavioral contexts, including feeding, sleepiness, social interaction, or cognitive activity (eg, anticipation), dominant theta oscillations (3–6 Hz) occur, widely distributed across the frontal and back areas of the head.

In early studies, the frontal topographic distribution of theta waves was associated with higher levels of attention network activity (Orekhova et al., 1999; Stroganova, Orehova, and Posikera, 1998; Orehova et al., 1999). One of these studies compared frontal theta activity while waiting for a game of hide-and-seek to periods of quiet attention (eg, bubble-watching) in different age groups (7-8 and 9-11 months). The authors reported differences in the power of theta oscillations (estimated in the range of 3.6-4.8 Hz), with relatively higher amplitude observed in younger infants (Orekhova et al., 1999; Stroganova and Orehova, 2007). This is consistent with the fundamental development of the executive cortical networks in infants and with other EEG studies showing a higher degree of theta wave synchrony in the frontal zone (over 8 months of age) indicating sustained attention (Bazhenova et al., 2007; Uhlhaas et al. ., 2010). However, it is still unclear whether the increase in theta amplitude occurs in other tasks. In contrast to the alpha rhythm of the infant, research on changes in theta frequency during development during infancy is scarce.

In addition, with developmental changes in the frequency spectrum and synchronization of neuronal oscillations, asymmetric brain activity becomes a more reliable measure of positive/negative emotion processing (Fox et al., 1992; Reference literature). According to Davidson and Fox (1982; REF), this lateralized EEG activity appears to be stable at 10 months of age, consistent with greater demonstration of social and emotional behavior. Indeed, consistent data show that right-sided frontal EEG asymmetry in infants is associated with behavioral inhibition and social withdrawal, while left-frontal asymmetry is associated with characteristic tendencies towards conventional approach or positive emotion (Fox and Henderson, 1999). Thus, most of the reviewed studies that characterize neuronal patterns of emotional behavior in this age group are focused on EEG asymmetries in the range of 3–12 Hz.

Although such asymmetries are currently the most effective indicator of emotional states in infants, however, the estimated age stability in different studies is not clearly defined. For example, Vuga et al (2008) report long-term persistence of frontal asymmetry for 6–36 months, while Jones et al (1997) report 24–30 months. Recent studies have shown moderate persistence between 10 and 24 months (Howarth, Fettig, Curby and Bell, 2016). These contradictions make it difficult to clarify the functional nature of frontal asymmetries when studying the processing and development of emotions in infants.

EEG studies and research methods

Based on the reviewed literature, we identified two lines of further research. One of them relates to neuronal patterns associated with the recognition of emotions. Thus, in this case, the main issue is how infants perceive and recognize the emotions of other people, as well as how their emotional perception develops. In the second line of research, EEG markers of differentiated emotional states expressed in infants in the form of specific moods, such as comfort, happiness, anxiety, sadness, involvement, etc., are studied in response to an evocative factor or situation (new toy, closeness of mother ), which may additionally be modulated (or not modulated) by a neuronal marker trait. The following describes the main EEG data on emotion processing in infants according to the above lines of investigation.

First Line of Research: ERP and Frontal Asymmetry

The study of emotions of different modalities in infants can be relatively less uncertain if done during development, given the improvement in the functioning of visual attention circuits. This allows investigators to apply more tests, which are of particular interest given the generally low signal-to-noise ratio in ERP studies in infants. In addition, attracting the attention of babies for a longer time is less difficult after the age of 6 months.

A large proportion of research methods for studying infant reactions to emotions are based on the ERP approach. The simplest assessment is to record ERP activity when infants observe images of joyful and frightened faces versus images of objects. Extended studies examining face-sensitive ERPs in infants have identified several components (i.e., N170, N290, Nc, P400) that are thought to be associated with different facial expressions (Allison et al., 1994, 1999 ; Batty and Taylor, 2006; De Haan and Nelson, 1999; Nelson and De Haan, 1996; Kobiella et al., 2007). The Nc component, occurring between 400 and 800 ms, is one of the most studied components in infant ERP studies. This component has a negative deviation and is mainly distributed over the areas of the front and central electrodes. Although it is not only elicited in response to facial expressions, reviewed studies show that topographical and temporal characteristics in infants differ from those associated with object perception (de Haan and Nelson, 1999; Taylor, McCarthy, Saliba, and Degiovanni , 1999).

Susceptibility to angry faces versus those expressing pain or fear has been studied in a 7 to 8 month old population using an ERP approach and frontal asymmetry (Missana, Grigutsch and Grossmann, 2014; Kobiella, Grossmann, Reid and Striano, 2008). In one of these studies, the Nc component was noted in ERP in response to emotions, more accentuated by the expression of anger. In this context, Nc has been interpreted as reflecting infant attention seeking. Comparing the pattern of frontal asymmetry in response to angry faces in infants with that in adults showed the opposite frontal asymmetry: a relatively higher degree of left frontal activation in adults (associated with a tendency to approach) and a relatively higher degree of right frontal activation in infants, suggesting motivational avoidance tendency.

In addition, the N290 component appears by the second half of the first year, indicating that infants recognize facial expressions based on social cues rather than simply based on a negative/positive significance dichotomy. For example, an angry facial expression has been shown to elicit a higher N290 amplitude compared to a frightened expression. Although both emotions are negative, an angry expression is thought to elicit a more uncomfortable reaction than a fearful expression, thus indicating a process of discriminating social cues (Kobiella et al., 2007).

The neural basis of emotional processing in infants along sensory modalities (visual-acoustic-tactile) is of great interest for research. Very few EEG studies have addressed emotion processing using multimodal experimental designs (Grossmann et al., 2006; Friedrich and Friederici, 2005). For example, in one of these studies, ERPs indicative of the processing of emotionally matched and unmatched face-voice pairs were examined in a population of 7-month-old infants. The results showed a distinct ERP pattern (mainly Nc and Pc) as a function of cross-modal emotional coherence (Grossmann, Striano, and Friederici, 2006). Thus, this indicates that the integration of emotional information of different modalities occurs at relatively early stages of life.

Therefore, the ERP approach may offer different directions for research into the processing and development of emotions in human infants. However, the main limitation is that unlike adults, infants do not show well-defined peak ERP responses. Instead, they show stronger slow wave activity, mainly during the first two years of life, indicating poor synaptic efficiency. As the persistence of brain responses increases with adulthood, more distinct ERP waveforms are expected to appear by about 4 years of age (Nelson and Luciana, 1998; Taylor, Batty, and Itier, 2004). ERP studies up to this age must be conducted under high levels of experimental control, which sometimes interferes with the desired environmental evaluation of emotions.

- Second line of research

As infants develop, they express emotional states through an observable set of facial expressions that increasingly resemble those used by adults. They smile to communicate happiness and cry to express displeasure or discomfort. In addition, infants already exhibit "emotional styles" in response to different evocative stimuli or events that vary in intensity and duration (Davidson, 2003, 2004). This emotional predisposition is associated with specific frontal EEG patterns that are characterized as early signs of infants' emotional abilities. Of the emotions studied at this age, happiness, fear, sadness, and dissatisfaction (compared to, for example, anger) receive the most attention because they are relatively easier to evoke in the laboratory with established normalized stimuli (e.g., images, facial expressions, films).

Essentially, the EEG frontal asymmetry pattern indicates an infant's predisposition or propensity for behaviors in the alienation-closeness range (e.g., Fox, Henderson, Rubin, Calkins and Schmidt, 2001), likely reflecting amygdala activity (Davidson, 2000). At baseline, at rest, frontal EEG asymmetry may be an important neuronal marker for predicting emotional responses in infants in response to evocative stimuli or events (Wheeler et al., 1993). For example, there is evidence that infants with right frontal asymmetry tend to cry more when separated from their mother at rest (Davidson and Fox, 1989; Fox et al., 1992). Currently, frontal asymmetry is the most commonly used approach to study emotional traits or abilities in infants (Coan and Allen, 2004; Davidson and Fox, 1989; Davidson, 1992; 1993; Fox, 1991, 1994).

Consistent with known models of frontal asymmetry (approach/alienation and positive-negative salience; Davidson 1993; 2002), resting frontal EEG activity has been suggested to reflect a predisposition to positive or negative emotion and the future ability of infants to regulate emotions. Part of the focus of this line of research is on potential clinical applications for predicting infants' predisposition to certain emotional disorders or styles. Indeed, activity in the frontal zone of the hemispheres at rest is considered an early neurophysiological marker of the risk of depression (Allen and Reznik, 2015). For example, there is a large body of evidence showing higher relative right-sided frontal EEG asymmetry during resting periods in infants (e.g., 10 months of age) from depressed mothers compared to infants from non-depressed mothers (Dawson et al., 1992; Diego et al. al., 2006; Field et al., 1995; 2000; Field and Diego, 2009; Jones et al., 2001; Jones, Field and Almeida, 2009). Other studies examining neuronal markers of separation anxiety also found increased right-sided frontal activity at rest in infants who cried in response to separation from their mother compared to those who did not (Davidson and Fox, 1989).

Frontal asymmetry revealed during the rest period can change in response to various factors that cause emotions. Thus, a feasible way to predict changes in emotional state in infants is to measure the effect on frontal activity of proximity-oriented stimuli (i.e., emotional touch, familiar voice) versus alienation-oriented stimuli (i.e., stranger, pushy behavior) (Coan et al., 2001; Coan and Allen, 2004; Ekman et al., 1990; Davidson and Fox, 1982). It is strongly recommended to simultaneously measure the correlates of physiological activation (heart rate) and engagement (gaze duration and gaze shift) using appropriate schemes (i.e. visual discrimination, social reference with toys, cross-modal transfer), especially if the main goal of the study is in assessing changes in the emotional state as a result of evocative stimuli.

In addition, one should take into account the type of emotionally evocative stimuli that is used to study patterns of frontal asymmetry. Individual differences in frontal activity asymmetry can reasonably be expected to affect infant response to the same evocative factor (Davidson and Fox, 1989). However, depending on the objectives of the study, a case-by-case approach or a normative approach may be applied. Thus, the previous recommendation applies to studies focusing on cortical activation asymmetry patterns as a robust predictor of emotional reactivity or motivational propensity to evocative stimuli. For example, the propensity of infants to cry or not cry in response to separation from their caregiver, or to smile or shy away in the presence of a stranger can be predicted based on individual features of frontal asymmetry. Within this approach, it is recommended to add a longitudinal component to explore the impact of early positive and negative emotional experiences on development (Calkins et al. 2002; Coan and Allen 2003; Davidson 1998; Gaertner et al. 2008; Hill-Sonderlund and Braungart- Rieker, 2008; Kochanska and Knaack, 2003; Wheeler, et al., 1993). In contrast, the normative approach is applied to those studies that are more focused on measuring frontal asymmetry in infants associated with emotional states induced under controlled experimental environmental conditions (Buss et al., 2003; Cattell and Scheier, 1961; Diaz and Bell , 2012; Fox et al., 2001;). Examples include differences in frontal asymmetry in infants caused by the display of joyful and sad facial expressions, stressful situations such as the approach of a stranger, or different types of novel stimuli.

In addition, when considering asymmetries in frontal activity in a non-clinical population, the combination of EEG recordings with other techniques, such as simultaneous facial expression coding, may provide additional information about categories of emotional states in infants. The facial expression coding approach involves examining right-sided and left-sided EEG patterns at baseline and under emotion-producing conditions (e.g. hide-and-seek) while encoding the infant's emotions (facial expressions), such as positive, negative, and neutral. In this regard, there is evidence showing a distinctive and independent pattern of left-sided frontal activation reflecting two types of infant smiles: a response to the mother and a response to the approach of a stranger (Fox and Davidson, 1988; see also Field et al., 2011; Jones et al. , 2001). In addition, the functional significance of the transient theta rhythm in infants was studied using the EEG method with video recording (Dawson et al., 1992; Field et al., 2011; Futagi et al., 1998). One of these studies showed that theta rhythm patterns in the anterior and posterior regions of the brain are associated with emotional responses such as crying and sucking, as well as other cortical activities such as looking and working with hands (Futagi et al., 1998). ).

Finally, when measuring frontal asymmetry, the applied mounting point of the reference electrode must be taken into account. Traditional reference points (ie umbo Cz, mastoid processes) cause problems in EEG power spectrum measurements (see Pivik et al., 1993; Hagemann et al., 2001). Thus, the main recommendation is to use a registration comparison scheme that is sensitive enough to account for individual variations in frontal asymmetry. Refer to the EEG literature for more information on choosing a point of reference (Hagemann, 2004; Nunez et al., 1994; Pivik et al., 1993).

In general, in the infant literature, frontal asymmetry has been identified as the predominant approach to measuring emotions in the early stages of development. However, we believe that inconsistencies still exist, probably due to different theoretical and empirical backgrounds. In the next section, we will discuss these contradictions and make some recommendations for future research.

Discussion

Most of the studies reviewed agree that asymmetric patterns of activity in the frontal areas can serve as a neuronal marker of emotional response in infants. We also considered that this frontal asymmetry, which becomes stable at around 10 months of age, correlates with the motivational properties of emotional states (closeness-withdrawal behavior) as well as experience and expression of positive/negative emotions (Dawson, 1994; Diaz and Bell , 2012; Fox, 1991, 1994). This does not mean that frontal asymmetry has a causal relationship with such emotional responses, since the evidence supporting this suggestion in infants is mainly based on correlational evidence and therefore may have alternative explanations. For example, the frontal activation pattern may also reflect developmental functional changes in relevant neural circuits (ie, anxious attention networks) or the effect of rewarding salience of stimuli.

In addition, although the number of studies confirming such a direct relationship is quite large in the adult literature, in studies involving infants we found that asymmetric frontal activity and the corresponding emotional experience and expression of emotions are not well understood outside the context of emotion recognition (for example, the main thus based on the visual distinction of facial expressions). Even fewer EEG studies investigating the relationship between frontal asymmetries and changes in emotional states have been conducted in the nonclinical population.

The second part of this discussion relates to the impact of individual differences in frontal asymmetric activation in the EEG and its functional significance in the context of non-clinical studies. When measuring cortical asymmetries in infants, either to obtain information about their emotional state in relation to evocative stimuli or to predict their emotional characteristics, there are sources of variation, mainly related to individual differences. In relation to the hypothesis of characteristic asymmetries in infants, the high heritability of EEG spectra makes it difficult to accurately determine whether frontal asymmetry is due to genetic predisposition or environmental influences (Coan, 2003; MacDhomhail et al., 1999; Lykken et al., 1982). In both cases, it is recommended to improve the methodological aspects to ensure the reliability of the measurements (eg, increase the sample size, increase the rest time, choose an appropriate comparison point wiring diagram). For example, measuring the uniformity of resting frontal asymmetry across multiple sessions will allow researchers to distinguish between changes due to a stable individual trait from changes in response to specific experimental manipulations (see Hagemann, 2000). Within the same experimental session, taking several measurements of frontal activity at rest can increase the reliability of the data, but it also has some disadvantages. In this regard, we noticed that most studies only take one measurement of frontal asymmetry at rest or at baseline. This is usually due to the fact that it is difficult for infants to remain calm in the laboratory for long periods of time without unwanted mood changes affecting the readings.

In addition, to improve the internal validity of the study and prevent potential confounding, recent studies compare data on the similarity of frontal asymmetry between mother and infant in emotionally charged situations (Collan and Allen, 2004; Jones et al., 2001; Atzaba-Poria, Deater-Deckard , Ann-Bell, 2017). In this regard, it may also be convenient to relate frontal EEG responses to simultaneous measurements of maternal behavior (i.e., positive or negative emotional impact) affecting the infant, to determine whether the functional significance of frontal EEG asymmetry is due to motivation-specific factors or a biological characteristic. (LoBue, Soap, Thrasher, DeLoache, 2011; Wen et al., 2017). Finally, when applying changes in frontal asymmetry depending on specific evocative stimulus conditions, it is recommended to control for individual differences due to age, as they can explain the typical inconsistencies in EEG power variations in relation to specific factors that cause emotions.

At some point, we found a formulation of frontal asymmetry prone to oversimplification when studied in infants, partly due to some data inconsistencies, and also due to the lack of a precise definition of what might represent emotional significance and motivational frontal asymmetric activity in infants under one year of age (as opposed to adults). For example, in infants (4-9 months of age), the relationship between right frontal EEG asymmetry and anger is not yet clear, because in some of the studies reviewed, emotion valence (positive-negative) was confused with motivational orientation (proximity-avoidance), making it difficult to distinguish between which of these (or a combination of them) reflects frontal asymmetry (Davidson and Fox, 1989; Harmon-Jones, 2004; He, Degnan, McDermott et al., 2010). Thus, it is very important for future research to determine the conditions in which frontal asymmetry is the most appropriate approach to study changes in emotions during an evocative task or stimulation. Alternatively, we found a promising ability model proposed by Coan and Allen (2006), which suggests that individual differences in frontal asymmetry would be more pronounced during an evocative task or emotional stimulation than at rest.

3. General provisions: modern perspectives and directions of research

In this review, we have highlighted the most important advances and theoretical perspectives regarding the emotional behavior of infants depending on the stage of neuronal development. In addition, we discussed the main advantages and disadvantages of using EEG to study the emotions of infants, as well as the strengths and weaknesses of the available results.

Interest in EEG methods in the study of the emotional development of infants during the first year of life has increased significantly during the last decade. Although the EEG does not provide accurate, high-resolution images of the brain, this method provides an important means of assessing the major neuronal features associated with an individual's emotional development during the first years of life. As such, ERP and power spectrum measurements have become fundamentally important for the study of cognitive neuroscience in infants. Other neuronal imaging modalities, such as source localization, can further clarify the interpretation of the ERP or frequency spectrum, but it is very difficult to map such activation on structural MRI brain images. This is practically impossible in non-clinical studies before the age of 36 months. Alternatively, magnetoencephalography (MEG) is an interesting technique for studying emotions, given the high accuracy of signal localization compared to EEG. However, while it may well be used in infants, it is more costly and technically more complex than EEG (see Imada et al., 2006).

The combination of EEG with other neuroimaging techniques has become a common practice in the study of cognitive and emotional spheres. For example, simultaneous recording of EEG and functional near-infrared spectroscopy (fNIRS) is an appropriate way to measure the role of prefrontal cortical activation in emotion processing (eg, Nishitani, Doi, Koyama and Shinohara, 2011). This co-registration is practical in infants because it requires less action on their part (eg Koch, Steinbrink, Villringer and Obrig, 2006). Particularly promising is the use of the hyperscan technique to understand interbrain synchronization of mother and infant during evocative experiences such as emotional bonding, holding, or speech (Hirata et al., 2014).

Some specific examples of the invention will be discussed in more detail below, including the best modes of application of the invention envisaged by the inventors. Examples of such specific embodiments are depicted in the accompanying drawings. Although the invention has been described in connection with these specific embodiments, it should be understood that this should not limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications and equivalents which may be included within the spirit and scope of the invention as defined by the appended claims.

general description

An effective and efficient system and device for collecting electroencephalographic (EEG) data from infants and young children is proposed. The system and method uses an EEG headset having electrodes located at optimal locations.

Implementation examples

Therefore, the system and device of the invention uses EEG measurements to provide more accurate measurement and monitoring of attention and engagement in infants and young children. In accordance with various embodiments, subjects are provided with an EEG headset for use in a laboratory setting. In particular embodiments, the EEG headset includes a plurality of electrodes placed in optimal positions. Data from individual electrodes can be processed before being continuously transferred to a data analyzer. The processing may include filtering to remove noise and artifacts, as well as compression and/or encryption. Separate electrodes are made with the possibility of contact with the scalp in different areas.

EEG electrodes allow monitoring and tracking of in situ activity, including levels of involvement. In accordance with various embodiments, the data collection mechanism is synchronized with the stimulus material, which allows the determination of aspects of the stimulus materials that cause specific neurological responses.

In accordance with various embodiments, an EEG headset stores data collected from a user under the influence of a stimulus material for transmission to a data analyzer.

The subject may wear a portable data collection mechanism during various activities. This allows data to be collected from a variety of sources while the subject is in a natural state. In particular embodiments, data collection can efficiently take place in a work or laboratory environment.

A number of neurological, neurophysiological and effector mechanisms can be integrated into the data collection mechanism. An EEG measures the electrical activity associated with postsynaptic currents that occur in the millisecond range. However, when properly analyzed, the surface EEG provides a wealth of electrophysiological information. A large amount of information is provided by a portable EEG device with electrodes.

According to various embodiments, subjects may be exposed to a predetermined or selected stimulus material. In other examples, no predefined or selected stimulus material is provided and the system collects data on the stimulus material that the user is exposed to during normal activities.

For example, several subjects may be provided with portable EEG monitoring systems with electrodes that allow activity to be monitored. The response data is analyzed and combined. In some examples, all response data is provided for data analysis. In other examples, interesting response data is provided to the data analyzer along with recorded stimulus material. In accordance with various embodiments, response data is analyzed and improved for each subject, and further analyzed and improved by integrating data from multiple subjects.

According to various embodiments, individual and integrated response data is stored numerically or presented graphically. To identify possible patterns, fluctuations, profiles, etc. analyzing measurement results from a plurality of subjects.

In accordance with various embodiments, the data may demonstrate a particular effectiveness of the stimulant material for a particular subgroup of subjects. A variety of stimulus materials can be analyzed. In accordance with various embodiments, improved data is generated by a data analyzer that performs both single modality measurement enhancements and intermodal measurement enhancements. According to various embodiments, brain activity is measured not only to determine areas of activity, but also to determine interactions and types of interactions between different areas. The techniques and mechanisms of the present invention recognize that interactions between neuronal regions provide for coordinated and organized behavior. Attention, emotions, memory, retention, priming, and other characteristics are based not only on one part of the brain, but also on network interactions between brain regions.

The techniques and mechanisms of the present invention further take into account that different frequency bands used for communication between multiple areas may indicate the effectiveness of stimuli. In particular embodiments, scores are calibrated for each subject and synchronized across subjects. In specific embodiments, templates are created for subjects in order to obtain a baseline for measurements of differences before and after stimulation.

FIG. 1 shows one example of a data acquisition system. Subjects are associated with data collection mechanisms. In accordance with various embodiments, subjects voluntarily apply data collection mechanisms, such as EEG caps, while exposed to specific stimulus materials provided by the stimulus presentation mechanism. Data collection mechanisms include persistent storage mechanisms and network interfaces that are used to transfer the collected data to the data analyzer. In other examples, data collection mechanisms include interfaces with computer systems that are configured to transmit data to the data analyzer over one or more networks.

Response materials for subjects may include people, actions, images, personal care compositions, and may include certain tastes, smells, appearances, textures, and/or sounds. In some examples, a stimulus material is selected for presentation to subjects.

According to various embodiments, subjects are connected to data collection mechanisms. Data acquisition mechanisms include EEG electrodes, although in some implementations may also include various measurement mechanisms, including neurological and neurophysiological measurement systems, for example, for electrooculogram, galvanic skin response measurement, electrocardiogram, pupil dilation, eye movement tracking, emotion expression encoding on the face, determining the reaction time, etc. In accordance with various embodiments, the data includes data on the central nervous system, the autonomic nervous system, and/or the effector system.

In specific embodiments, the collected data is digitized and stored for later analysis. In particular embodiments, the collected data may be analyzed in real time.

In one particular embodiment, the data collection mechanism includes EEG measurements taken using electrodes placed on the scalp.

FIG. 2A and 2B show a data acquisition mechanism including a plurality of electrodes. According to various embodiments, the data acquisition mechanism is a soft cap containing electrodes configured to contact the scalp without the use of electrically conductive gels. Signals can be sent to a controller/processor for immediate transmission to a data analyzer or stored for later analysis. A controller/processor can be used to synchronize data with stimulus materials.

FIG. 2A and 2B illustrate the data collection mechanism. The data acquisition mechanism includes a plurality of electrodes including. It should be noted that while the specific electrode design may vary between implementations, a preferred electrode design is provided herein.

In FIG. 2A shows the location of the electrodes (13) (highlighted in yellow, while represented in light gray in the black and white image) for effective assessment of positive and negative emotions of infants with an acceptable level of accuracy. The areas of the scalp were chosen in such a way as to provide symmetrical recording in the frontal, temporal and parietal zones. The electrodes on the frontal pole (AF3, AF4, F5, F6, FC1, FC2) make it possible to assess EEG asymmetry in infants. Temporal electrodes (T2, T3) allow you to study pleasant / unpleasant sensations in the auditory zone. The parietal/centrotemporal electrodes (P7, P8, CPz) allow the study of attracting attention to emotional speech and somatosensory activity. Occipital electrodes (O1, O2) measure visual processing of emotions. A1 and A2 correspond to comparison points. The electrode position nomenclature template is taken from the guidelines of the American Electroencephalographic Society, 1991; Journal of Clinical Neurophysiology, 8, pp. 200-201.

In FIG. 2B shows the placement of the electrodes (17) (highlighted in red, while represented in dark gray in the black and white image) to effectively assess the positive and negative emotions of infants with a higher level of accuracy. The areas of the scalp were chosen in such a way as to provide symmetrical recording in the frontal, temporal and parietal zones. The electrodes on the frontal pole (AF3, AF4, F5, F6, FC1, FC2) make it possible to assess EEG asymmetry in infants. Temporal 30 modified page electrodes (T2, T3) allow you to study pleasant / unpleasant sensations in the auditory zone. Parietal/centroparietal electrodes (P7, P8, СР3, СР4, CPz) allow to study the attraction of attention to emotional/social-significant speech and somatosensory activity. Occipital electrodes (PO3, PO4, 01, O2) measure visual emotion processing and frontal-parietal interactions. A1 and A2 correspond to comparison points. The electrode position nomenclature template is taken from the guidelines of the American Electroencephalographic Society, 1991; Journal of Clinical Neurophysiology, 8, pp. 200-201.

In accordance with various embodiments, data acquisition by the electrodes is synchronized with the stimulus material presented to the user. The data acquisition mechanism also includes a transmitter and/or receiver for sending the collected data to a data analysis system.

In some examples, the transceiver may be connected to a computer system, which then transmits data over a wide area network to a data analyzer.

It should be noted that some components of the data collection mechanism are not shown for clarity.

Queries based on response scores may include attention, emotion, and performance scores. Such requests may relate to materials that led to particular scores. In queries based on response profile measurements, mean thresholds, measures of variance, number of detected peaks, and so on can be applied. Group response requests may include group statistics such as mean, variance, slope, p-value, etc., group size, and outlier estimation metrics.

FIG. 3 illustrates one example of data collection. Receive user information from the subject to which the data collection mechanism is provided. Receive data from the mechanism for collecting data on the subject. In some specific embodiments, EEG data, electrooculograms, pupillary dilation data, facial emotion encoding data, video, images, audio, etc. may be transmitted. from the subject to the data analyzer. In particular embodiments, only EEG data is transmitted. According to various embodiments, the response and associated data are transmitted directly from the EEG cap via a WAN interface to the data analyzer. In particular embodiments, the response and associated data is transmitted to the computer system, which then compresses and filters the data before transmitting the data to the data analyzer over the network.

In particular embodiments, the communication device sends data to the response integration system. In accordance with various embodiments, the response integration system integrates the analyzed and improved responses to the stimulus material using information about the attributes of the stimulus material. In specific embodiments, the response integration system also collects and integrates the user's behavioral responses with the analyzed and improved response data for more efficient measurement and tracking from stimulus materials.

While the above invention has been described in detail for purposes of clarity and better understanding, it will be apparent that certain changes and modifications may be made within the scope of the appended claims. Thus, the present embodiments are to be considered as illustrative and non-limiting, and the present invention is not to be limited to the details set forth herein, but may be modified within the scope and equivalents of the appended claims.

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Claims (8)

1. A device for studying the cognitive and emotional development of infants and young children, containing electrodes for electroencephalography (EEG), configured to provide optimal point contacts with the scalp of an infant or young child, and the EEG electrodes are located in accordance with option A or IN: A) pairs of electrodes are placed to provide symmetrical recording in the frontal, temporal and parietal regions, with six electrodes placed in the frontal pole region to assess EEG asymmetry in an infant or young child, two electrodes are placed in the temporal region to study pleasant / unpleasant sensations in the auditory zone, and three electrodes are placed in the parietal region to study the attraction of attention to emotional speech and somatosensory activity; B) pairs of electrodes are placed to provide symmetrical recording in the frontal, temporal and parietal regions, with six electrodes placed in the frontal pole region to assess EEG asymmetry in an infant or young child, two electrodes are placed in the temporal region to study pleasant / unpleasant sensations in the auditory zone, five electrodes were placed in the parietal region to study the attentional attraction to emotional speech and somatosensory activity, and four electrodes were placed in the occipital region to measure visual processing of emotions. 2. The apparatus of claim 1, further comprising a flexible support structure attached to the electrodes. 3. The apparatus of claim 1, further comprising amplifiers coupled to the electrodes, the data from each of the electrodes being individually amplified and isolated. 4. The device according to claim 3, in which the amplifiers are made on a flexible printed circuit board. 5. The apparatus of claim 3, wherein the amplifier transmits the combined data wirelessly to a remote data analyzer. 6. The apparatus of claim 3, wherein the amplified data is combined with amplified data from other EEG headset electrodes.

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