Citation Context

...rability of the two selection systems, we double coded the cohort originally selected using the 7-point scale system utilized by Calkins et al. (1996) and Kagan and Snidman (1991). We then utilized the selection criteria outlined above (using the 7-point scales) to place infants from the initial cohort into each of the three temperament groups. We computed observed percent agreement and Cohen’s K between the two selection/ classification outcomes. Observed percent agreement was 80.3% whereas Cohen’s K was .66. This suggests that there was good agreement between the two classification systems (Fleiss, 1981). As a further check, we examined whether the temperament groups within the two cohorts differed on any of the major outcome measures (behavioral inhibition, social reticence, EEG asymmetry). They did not. Procedure Following the initial selection, families were invited to the laboratory when their infants were 9, 14, 24, and 48 months of age. When the infants were 9 months of age, brain electrical activity (EEG) was recorded and mothers completed a temperament survey. At each of the subsequent ages, EEG was recorded, mothers completed age-appropriate temperament surveys, and children’s reacti...

Citation Context

...blings and nonsiblings) were cared for in the same setting. Based on this survey, children were classified as having been in exclusive home care or in nonparental care with at least one nonsibling during the first 24 months of life. During the 4-year visit, mothers completed the Colorado Child Temperament Inventory (CCTI; Buss & Plomin, 1984; Rowe & Plomin, 1977). The CCTI is a 30-item parental report that assesses six temperament dimensions. The dimensions of interest were Shyness and Sociability. As a measure of adjustment/maladjustment, mothers completed the Child Behavior Checklist (CBCL; Achenbach & Edelbrock, 1983). The CBCL is a 113-item checklist in which parents use a 3-point scale to rate how descriptive of their own child a series of behavior problems are. The CBCL yields eight narrow-band factors that are further reduced to two broadband factors, Internalizing and Externalizing behavior problems. The prevalence of Internalizing and Externalizing behavior problems were of particular interest in this study. Attrition by temperament group. Of the 153 infants selected (Low Reactive, n = 52; High Negative, n = 56; High Positive, n = 45), 122 participated at 9 months of age (Low Reactive, n = 47; High N...

Citation Context

...ct baseline measures of EEG from adult subjects (Davidson, 1988). Prior to the recording of EEG from each subject, a 50 µV 10 Hz signal was input into each of the channels and this amplified signal was recorded. This signal of known frequency and amplitude was later used for calibration purposes. At each age, the experimenter began preparing for EEG collection by measuring the circumference of the child’s head in order to select a Lycra stretch cap of appropriate size. The stretch caps have electrodes for EEG recording sewn into the fabric according to the 10–20 system of electrode placement (Jasper, 1958). Thus, the electrode cap allows for a noninvasive, efficient, yet accurate, method of electrode placement. In order to ensure that the cap stayed in place during the recording, elastic straps on each side of the cap were snapped onto a cotton vest worn by the infant. At 9, 14, and 24 months, the cap was further secured with an elastic headband. A small amount of abrasive gel (Omni-prep) was inserted into each of the six active sites on the cap (F3, F4, P3, P4, O1, and O2) as well as the reference site at the vertex (CZ). Using the blunt end of a Q-tip, each site was gently abraded. Following ...

Citation Context

...nces among individuals in regional brain electrical activity must be conservative with regard to actual differences in neural location and activity. Nonetheless, recent research from Davidson’s laboratory would seem to support the adequacy of the EEG in reflecting neural activity and the role of prefrontal cortex in emotion. In a recent paper, Davidson and coworkers (Larson et al., 1998) report a significant correlation between glucose metabolism and EEG activity suggesting that differences in EEG power may indeed reflect regional patterns of neural activation. Of interest are recent studies (Davidson & Irwin, 1999) utilizing functional MR1 neuroimaging technology that have found a reciprocal relation between amygdala activity and prefrontal activation. These studies suggest that prefrontal activation inhibits the amygdala in response to stimuli designed to elicit negative affect. The amygdala is a structure in the limbic system implicated in conditioned fear responses (Davis, 1992). Greater amygdala activation has been associated with the potentiation of conditioned fear (Davis, Hitchcock, & Rosen, 1987). Thus, individual variation in the degree to which prefrontal activity inhibits amygdala may be crit...

Citation Context

...re survey in which they were asked to report if the child was currently or had in the past been cared for on a regular basis by someone other than the child’s mother or father. In addition to describing the type of care, mothers were asked to report how many children (both siblings and nonsiblings) were cared for in the same setting. Based on this survey, children were classified as having been in exclusive home care or in nonparental care with at least one nonsibling during the first 24 months of life. During the 4-year visit, mothers completed the Colorado Child Temperament Inventory (CCTI; Buss & Plomin, 1984; Rowe & Plomin, 1977). The CCTI is a 30-item parental report that assesses six temperament dimensions. The dimensions of interest were Shyness and Sociability. As a measure of adjustment/maladjustment, mothers completed the Child Behavior Checklist (CBCL; Achenbach & Edelbrock, 1983). The CBCL is a 113-item checklist in which parents use a 3-point scale to rate how descriptive of their own child a series of behavior problems are. The CBCL yields eight narrow-band factors that are further reduced to two broadband factors, Internalizing and Externalizing behavior problems. The prevalence of Int...

Citation Context

...ring the baseline recordings. In a separate study, Fox, Bell, and Jones (1992) replicated this finding and found the frontal EEG pattern to be stable across the second half of the first year of life. Henriques and Davidson (1990, 1991) reported that adults with clinical depression, as well as adults who were depressed and currently in remission, displayed this pattern of right frontal EEG asymmetry. Together, these findings suggest that patterns of right frontal EEG asymmetry may serve as a marker of an underlying disposition rather than simply reflecting current affective state. For example, Davidson (1992) has argued that this EEG pattern reflects a diathesis around which stressful events may trigger the expression of negative affect or depressive symptomatology. In addition to being related to specific affective states, Fox and his colleagues have found relations between EEG asymmetry and shyness in adults and reticence in children. Specifically, adults who rated themselves as high in shyness displayed right frontal EEG asymmetry (Schmidt & Fox, 1994). Preschool and elementary school age children who displayed social reticence in a peer situation were more likely to display right frontal EEG a...

Citation Context

...us positive social initiation when placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins, Rubin, & Coplan, 1995; Kagan, Reznick, & Snidman, 1987; Schmidt, Fox, & Schulkin, 1999). In addition, there have been a number of studies that have described the antecedents and developmental trajectories of behaviorally inhibited children. For example, Kagan, Reznick, Clarke, Snidman, and Garcia-Coll (1984) reported on 43 4-year-old children, 22 of whom were identified as inhibited at 21 months of age. At age 4, the 22 inhibited children were more socially inhibited with unfamiliar peers and more vigilant and hesitant during cognitive testing compared to the 21 children identified as uninhibited. At 5 years of age, the same 22 children were mor...

Citation Context

...late negative affect by utilizing approach behaviors whereas infants exhibiting right prefrontal EEG asymmetry may be less likely to modulate negative responses. Examination of differences in frontal power between groups might have assisted in the interpretation of the different patterns of EEG asymmetry. Activation measured from scalp leads over left prefrontal cortex has been associated with the expression of positive affect and approach behaviors whereas activation of right prefrontal cortex has been associated with the expression of negative affect and withdrawal behaviors. Both Davidson (Henriques & Davidson, 1991) and Fox (Fox et al., 1995) have reported that differences in frontal power are associated with these behavioral or motivational responses. Despite significant group differences in frontal EEG asymmetry, we could find no consistent pattern of difference between groups in either left or right frontal EEG power/ activation. Examination of factors associated with change in inhibition over time indicated that early childcare environments might be important in understanding the patterns of continuity and change in the expression of behavioral inhibition. Infants originally selected as High Negative...

Citation Context

...1998) report a significant correlation between glucose metabolism and EEG activity suggesting that differences in EEG power may indeed reflect regional patterns of neural activation. Of interest are recent studies (Davidson & Irwin, 1999) utilizing functional MR1 neuroimaging technology that have found a reciprocal relation between amygdala activity and prefrontal activation. These studies suggest that prefrontal activation inhibits the amygdala in response to stimuli designed to elicit negative affect. The amygdala is a structure in the limbic system implicated in conditioned fear responses (Davis, 1992). Greater amygdala activation has been associated with the potentiation of conditioned fear (Davis, Hitchcock, & Rosen, 1987). Thus, individual variation in the degree to which prefrontal activity inhibits amygdala may be critical for the inhibition or lack of inhibition of fear behaviors. Kagan and his colleagues have suggested that the temperamental origins of behavioral inhibition may be related to the excitability of certain areas of the amygdala, specifically the central nucleus (Kagan & Snidman, 1991). This hypothesis is based in part on those animal studies in which this area has been i...

Citation Context

...wing film clips selected to elicit positive emotion. Davidson and Fox (1989) found that 10-month-old infants who cried during a 1-minute period of maternal separation showed significant right frontal asymmetry during a baseline recording that took place before the mother left the room. In contrast, infants who did not cry during the separation period displayed significant left frontal asymmetry during the baseline recordings. In a separate study, Fox, Bell, and Jones (1992) replicated this finding and found the frontal EEG pattern to be stable across the second half of the first year of life. Henriques and Davidson (1990, 1991) reported that adults with clinical depression, as well as adults who were depressed and currently in remission, displayed this pattern of right frontal EEG asymmetry. Together, these findings suggest that patterns of right frontal EEG asymmetry may serve as a marker of an underlying disposition rather than simply reflecting current affective state. For example, Davidson (1992) has argued that this EEG pattern reflects a diathesis around which stressful events may trigger the expression of negative affect or depressive symptomatology. In addition to being related to specific affective s...

Citation Context

...reticence was created by standardizing the mean proportion of time spent engaged in unoccupied and onlooker behaviors across both play sessions (see also Coplan et al., 1994). The standardized score of social reticence was used as the index of inhibition at 4 years. Scores on this index ranged from —1.19 to 4.55. Maternal questionnaire data. At each assessment point, mothers were asked to complete a variety of questionnaires including temperament reports and demographic information. At 9 months of age, maternal reports of temperament were gathered using the Infant Behavior Questionnaire (IBQ; Rothbart, 1981). The 1BQ is an 87-item parent rating form in which parents are asked to rate the frequency of specific infant behaviors as they occurred in the previous week. Parents rate the frequency of behaviors using a 7-point scale with an eighth option for ―Does not apply.‖ Scaled scores are derived from the measure by taking the mean ratings on all items in the particular scale, omitting the items marked as ―Does not apply.‖ Of particular interest in this study were the scales ―Fear‖ (distress and extended latency to approach intense or novel stimuli), and ―Smiling and Laughing.‖ The Fear scale has 16...

Citation Context

... reactive infants seen at 41/2 years of age had been consistently inhibited at each of the assessment points over the 4-year period. Sixty-seven percent of the low reactive children, but only 27% of the high reactive children, were classified as uninhibited with peers. Kagan et al. (1998) argued that this pattern of data supports the notion that negative reactivity is a temperamental trait and an antecedent in the development of behavioral inhibition. One of the issues in the study of the continuity of inhibition is the characterization of its form across development. In his Handbook chapter, Caspi (1998) describes five different types of continuity of personality to be considered in the study of developmental change. Four of these (differential, absolute, structural, ipsative) refer to homotypic continuity, which is continuity of similar behaviors or phenotypic attributes over time. The fifth, heterotypic continuity, refers to continuity of an inferred genotypic attribute presumed to underlie diverse phenotypic behaviors. It is this latter type of continuity that characterizes developmental change in behavioral inhibition. The term behavioral inhibition is used to describe temperamental diffe...

Citation Context

...experience of nonparental care. A second group of infants, selected at 4 months of age for patterns of behavior thought to predict temperamental exuberance, displayed a high degree of continuity over time in these behaviors. Article: INTRODUCTION There are multiple reports in the research literature of the behavioral and physiological correlates of the temperamental pattern known as behavioral inhibition. Inhibited toddlers and preschool children are characterized as displaying vigilant behaviors and motor quieting when confronted with novelty. They are unlikely to approach unfamiliar adults (Calkins, Fox, & Marshall, 1996), show little spontaneous positive social initiation when placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins,...

Citation Context

...here are clearly many children who do not remain inhibited across the early years of life. We know little about these children or the factors that may contribute to the changes in their behavior over time. One factor that may contribute to the continuity of inhibition over time is the physiological disposition of infants to express negative affect and withdrawal in response to novelty. A variety of data suggests that the pattern of the resting electroencephalogram (EEG) may reflect an individual bias to respond with positive or negative affect to stressful situations. Davidson and colleagues (Tomarken, Davidson, & Henriques, 1990) reported that increased resting right frontal EEG activation was associated with adults’ self-reports of higher levels of global negative affect (fear, disgust, sadness, and anger) while watching film clips selected to elicit negative emotions (disgust, sadness, and anger). The relation between resting frontal asymmetry and selfreported negative affect was particularly strong for the subjects’ ratings of fear. In contrast, resting frontal asymmetry was not related to the adults’ ratings of global positive affect (happiness, amusement, and interest) when viewing film clips selected to elicit ...

Citation Context

...udy social reticence (e.g., Fox et al., 1996; Rubin, Coplan, Fox, & Calkins, 1995). Using a variety of observational taxonomies, including the Play Observation Scale (Rubin, 1989), these researchers have derived a measure of socially wary, anxious, and reticent behaviors in the preschool play group. This measure, comprising observed reticence and anxiety during free play and an inclination to avoid making a speech in the presence of unfamiliar peers, has been found to be contemporaneously associated with maternal reports of both dispositional shyness and internalizing behavior problems (e.g., Coplan, Rubin, Fox, & Calkins, 1994). In contrast, other forms of nonsocial play have been described in which children are simply more focused on objects than on people, and this form of solitary play does not show contemporaneous relations with measures of distress or anxiety. Thus, reticence is conceptually related to behavioral inhibition based on the common underlying motivation to avoid novelty due to the negative affect elicited by novel stimuli. Reticence reflects a specific form of nonsocial behavior, one that is accompanied by signs of anxiety and wariness (Asendorpf, 1990; Coplan et al., 1994). Despite variation in th...

Citation Context

...rontal EEG asymmetry may serve as a marker of an underlying disposition rather than simply reflecting current affective state. For example, Davidson (1992) has argued that this EEG pattern reflects a diathesis around which stressful events may trigger the expression of negative affect or depressive symptomatology. In addition to being related to specific affective states, Fox and his colleagues have found relations between EEG asymmetry and shyness in adults and reticence in children. Specifically, adults who rated themselves as high in shyness displayed right frontal EEG asymmetry (Schmidt & Fox, 1994). Preschool and elementary school age children who displayed social reticence in a peer situation were more likely to display right frontal EEG asymmetry as well (Fox et al., 1995; Fox et al., 1996). And Calkins et al. (1996) reported that infants displaying high motor arousal and negative affect at four months of age were more likely to display right frontal EEG activity at nine months of age and behavioral inhibition at 14 months of age. A recent study by Schmidt et al. (1999) illustrates these relations. Seven-year-old children, observed to be shy in a peer situation, exhibited right fronta...

Citation Context

...be dampened with ablation of selected brain regions within this circuit (Davis, 1992; Davis, Hitchcock, & Rosen, 1987). Based on these findings, Kagan argued that infants’ motor and affective reactions to novelty might reflect activity in this fear circuit. Specifically, infants exhibiting high degrees of motor arousal and negative affect in response to novelty may do so because of an over-activated fear circuit. This over-activation would later be expressed in the form of behavioral inhibition to the unfamiliar during the toddler and preschool years. More recent work of Davis and colleagues (Davis, 1998; Davis & Lee, 1998) has suggested, however, that areas immediately outside the amygdala (specifically the bed nucleus) may be associated with nonconditioned fear and perhaps this neural center may have an important role in anxiety rather than fear. Irrespective of whether the neural circuits underlying inhibition are through the amygdala or bed nucleus, it is interesting to note that outputs from either lead to changes in autonomic, neurendocrine, and behavioral/motor responses which have a parallel to the findings in behavioral inhibition work with human infants and children. Of significance...

Citation Context

... a complete description of the testing room). The child sat in the space chair (a chair covered in silver fabric) and the mother sat on a sofa across the room. EEG was collected as the child watched a computer-generated video. In addition, the child was asked to sit quietly and (1) look at a toy spaceship that was placed approximately 18 inches from his / her face and then (2) sit with his / her eyes closed. The eyes-opened and eyes-closed segments each lasted for one minute. The eyes-open/eyesclosed conditions are similar to those used to collect baseline measures of EEG from adult subjects (Davidson, 1988). Prior to the recording of EEG from each subject, a 50 µV 10 Hz signal was input into each of the channels and this amplified signal was recorded. This signal of known frequency and amplitude was later used for calibration purposes. At each age, the experimenter began preparing for EEG collection by measuring the circumference of the child’s head in order to select a Lycra stretch cap of appropriate size. The stretch caps have electrodes for EEG recording sewn into the fabric according to the 10–20 system of electrode placement (Jasper, 1958). Thus, the electrode cap allows for a noninvasive,...

Citation Context

... infant was unable to continue with a session, scores were prorated for the amount of time (number of episodes) that the infant missed. All sessions were videotaped, allowing for the later coding of infant reactivity. Infants from both cohorts were selected based on the amount of motor reactivity as well as positive and negative affect expressed during the presentation of the novel sights and sounds. The methods of coding and quantifying reactivity varied slightly between the two cohorts. In the first cohort, coding was based on the procedures described previously by Calkins et al. (1996) and Kagan and Snidman (1991). Specifically, the frequencies of the following behaviors were coded during stimulus presentation: (1) Motor Activity (arm and leg movements greater than 45° from resting position, burst of two or more arm and leg movements, back arches, hyperextension of arms and legs); (2) Positive Affect (smiling and neutral or positive vocalizations); and (3) Negative Affect (fussing, fretting, and crying). Interrater reliability was computed on approximately 20% of the sample. Pearson correlations between pairs of raters ranged from .78 to .86. Infants who were extreme on the dimensions of motor activity...

Citation Context

...his EEG pattern reflects a diathesis around which stressful events may trigger the expression of negative affect or depressive symptomatology. In addition to being related to specific affective states, Fox and his colleagues have found relations between EEG asymmetry and shyness in adults and reticence in children. Specifically, adults who rated themselves as high in shyness displayed right frontal EEG asymmetry (Schmidt & Fox, 1994). Preschool and elementary school age children who displayed social reticence in a peer situation were more likely to display right frontal EEG asymmetry as well (Fox et al., 1995; Fox et al., 1996). And Calkins et al. (1996) reported that infants displaying high motor arousal and negative affect at four months of age were more likely to display right frontal EEG activity at nine months of age and behavioral inhibition at 14 months of age. A recent study by Schmidt et al. (1999) illustrates these relations. Seven-year-old children, observed to be shy in a peer situation, exhibited right frontal EEG asymmetry during baseline conditions compared to their nonshy counterparts. When placed in an emotionally evocative situation, the shy children displayed signs of anxiety th...

Citation Context

...ey were asked to report if the child was currently or had in the past been cared for on a regular basis by someone other than the child’s mother or father. In addition to describing the type of care, mothers were asked to report how many children (both siblings and nonsiblings) were cared for in the same setting. Based on this survey, children were classified as having been in exclusive home care or in nonparental care with at least one nonsibling during the first 24 months of life. During the 4-year visit, mothers completed the Colorado Child Temperament Inventory (CCTI; Buss & Plomin, 1984; Rowe & Plomin, 1977). The CCTI is a 30-item parental report that assesses six temperament dimensions. The dimensions of interest were Shyness and Sociability. As a measure of adjustment/maladjustment, mothers completed the Child Behavior Checklist (CBCL; Achenbach & Edelbrock, 1983). The CBCL is a 113-item checklist in which parents use a 3-point scale to rate how descriptive of their own child a series of behavior problems are. The CBCL yields eight narrow-band factors that are further reduced to two broadband factors, Internalizing and Externalizing behavior problems. The prevalence of Internalizing and Externa...

Citation Context

...ncy of specific behaviors using a 7-point Likert-type scale. As on the 1BQ, there is an eighth option for ―Does not apply.‖ Six scale scores are created from the measure by taking the mean of items for a particular scale, omitting all items answered with ―Does not apply.‖ Of particular interest in this study were the scales Social Fearfulness (inhibition, distress, withdrawal, or signs of shyness in novel or uncertainty-provoking situations) and Pleasure (smiling, laughter, and other hedonically positive vocalizations or playful activity in a variety of nonthreatening or familiar situations) (Goldsmith, 1996). The Social Fearfulness scale consists of 19 items and has an internal consistency alpha of .87. The Pleasure scale consists of 19 items and has an internal consistency alpha of .86. During the 24-month visit, mothers completed a nonparental care survey in which they were asked to report if the child was currently or had in the past been cared for on a regular basis by someone other than the child’s mother or father. In addition to describing the type of care, mothers were asked to report how many children (both siblings and nonsiblings) were cared for in the same setting. Based on this surve...

Citation Context

...s in the research literature of the behavioral and physiological correlates of the temperamental pattern known as behavioral inhibition. Inhibited toddlers and preschool children are characterized as displaying vigilant behaviors and motor quieting when confronted with novelty. They are unlikely to approach unfamiliar adults (Calkins, Fox, & Marshall, 1996), show little spontaneous positive social initiation when placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins, Rubin, & Coplan, 1995; Kagan, Reznick, & Snidman, 1987; Schmidt, Fox, & Schulkin, 1999). In addition, there have been a number of studies that have described the antecedents and developmental trajectories of behaviorally inhibited children. For example, Kagan, Reznick, Clarke, Snidm...

Citation Context

...NTRODUCTION There are multiple reports in the research literature of the behavioral and physiological correlates of the temperamental pattern known as behavioral inhibition. Inhibited toddlers and preschool children are characterized as displaying vigilant behaviors and motor quieting when confronted with novelty. They are unlikely to approach unfamiliar adults (Calkins, Fox, & Marshall, 1996), show little spontaneous positive social initiation when placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins, Rubin, & Coplan, 1995; Kagan, Reznick, & Snidman, 1987; Schmidt, Fox, & Schulkin, 1999). In addition, there have been a number of studies that have described the antecedents and developmental trajectories of behaviorally inhibited children...

Citation Context

... months of age the majority of power was localized to the 4–6 Hz frequency range, while at older ages there was a clear shift in the locus of power to 6–8 Hz. Previous research with human infants has documented this shift in spectral power across the first years of life (Fox & Bell, 1990; Schmidt & Fox, 1998; Stroganova, Orekhova, & Posikera, 1999). The data used in analyses were the log power data from both the frontal and parietal regions, as well as laterality scores that were computed for each region at each age. Power and activation are thought to be reciprocally related (Davidson, 1988; Lindsley & Wicke, 1974). High power reflects low activation at a particular electrode site while low power reflects high activation. Laterality scores (ln right–ln left) are used to reflect the relative power in the right and left hemispheres. A positive score reflects greater R-power (or increased L-activation), whereas a negative score reflects greater L-power (or increased Ractivation). Observed behavioral inhibition. At 14 and 24 months, the infant’s reactions to unfamiliar stimuli in the laboratory were coded to provide an index of behavioral inhibition (see Calkins et al., 1996; Kagan et al., 1987; Reznick, Gi...

Citation Context

...on due to the level of their unpredictability in social situations. The change in the nature of the eliciting stimulus conditions from inanimate and social situations to social situations specifically warrants the introduction of different terminology for the behaviors in older children. Fox and Rubin have used the term social reticence to reflect behavioral inhibition in social situations. They and their colleagues have conducted detailed observations of children’s behaviors during free play, speech-making, and cooperative tasks with unfamiliar peers in order to study social reticence (e.g., Fox et al., 1996; Rubin, Coplan, Fox, & Calkins, 1995). Using a variety of observational taxonomies, including the Play Observation Scale (Rubin, 1989), these researchers have derived a measure of socially wary, anxious, and reticent behaviors in the preschool play group. This measure, comprising observed reticence and anxiety during free play and an inclination to avoid making a speech in the presence of unfamiliar peers, has been found to be contemporaneously associated with maternal reports of both dispositional shyness and internalizing behavior problems (e.g., Coplan, Rubin, Fox, & Calkins, 1994). In con...

Citation Context

... to predict temperamental exuberance, displayed a high degree of continuity over time in these behaviors. Article: INTRODUCTION There are multiple reports in the research literature of the behavioral and physiological correlates of the temperamental pattern known as behavioral inhibition. Inhibited toddlers and preschool children are characterized as displaying vigilant behaviors and motor quieting when confronted with novelty. They are unlikely to approach unfamiliar adults (Calkins, Fox, & Marshall, 1996), show little spontaneous positive social initiation when placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins, Rubin, & Coplan, 1995; Kagan, Reznick, & Snidman, 1987; Schmidt, Fox, & Schulkin, 1999). In addition, there have been a number of studies...

Citation Context

...g behavior problems (e.g., Coplan, Rubin, Fox, & Calkins, 1994). In contrast, other forms of nonsocial play have been described in which children are simply more focused on objects than on people, and this form of solitary play does not show contemporaneous relations with measures of distress or anxiety. Thus, reticence is conceptually related to behavioral inhibition based on the common underlying motivation to avoid novelty due to the negative affect elicited by novel stimuli. Reticence reflects a specific form of nonsocial behavior, one that is accompanied by signs of anxiety and wariness (Asendorpf, 1990; Coplan et al., 1994). Despite variation in the specific behaviors across different ages, reticence and behavioral inhibition provide age-appropriate measures of a common psychological state. A number of studies using parent report measures of temperament to identify inhibited children have also found moderate continuity in this trait. Sanson, Pedlow, Cann, Prior, and Oberklaid (1996) reported findings from the Australian Temperament Project in which they assessed 501 children longitudinally, beginning at 4 to 8 months of age and continuing through 5 to 6 years of age. The authors found few r...

Citation Context

...n placed with unfamiliar peers (Rubin, Hastings, Stewart, Henderson, & Chen, 1997), and are thought of by parents and peers as anxious and fearful (Garcia-Coll, Kagan, & Reznick, 1984; Rubin, Nelson, Hastings, & Asendorpf, 1999). In addition, there appears to be a unique pattern of physiology associated with this group. Reports indicate that they display high and stable heart rate, elevated home baseline cortisol, amplified EMG amplitude to a startle stimulus, and right frontal EEG activation (Calkins et al., 1996; Fox, Schmidt, Calkins, Rubin, & Coplan, 1995; Kagan, Reznick, & Snidman, 1987; Schmidt, Fox, & Schulkin, 1999). In addition, there have been a number of studies that have described the antecedents and developmental trajectories of behaviorally inhibited children. For example, Kagan, Reznick, Clarke, Snidman, and Garcia-Coll (1984) reported on 43 4-year-old children, 22 of whom were identified as inhibited at 21 months of age. At age 4, the 22 inhibited children were more socially inhibited with unfamiliar peers and more vigilant and hesitant during cognitive testing compared to the 21 children identified as uninhibited. At 5 years of age, the same 22 children were more inhibited with peers in both l...

Citation Context

...ve affect in response to a series of novel visual and auditory stimuli (Kagan & Snidman, 1991). One-third of the high reactive infants were inhibited at either 14 or 21 months of age. In contrast, very few infants who were selected based on their low levels of reactivity were inhibited at later ages. High reactive infants also showed greater sympathetic reactivity than did low reactive infants (Snidman, Kagan, Riordan, & Shannon, 1995). In a follow-up of these selected infants, 46% of the children who had been high reactive at 4 months of age were classified as inhibited at 41/2 years of age (Kagan, Snidman, & Arcus, 1998). In contrast, only 10% of children who had been low reactive as infants were classified as inhibited. Thirteen percent of the high reactive infants seen at 41/2 years of age had been consistently inhibited at each of the assessment points over the 4-year period. Sixty-seven percent of the low reactive children, but only 27% of the high reactive children, were classified as uninhibited with peers. Kagan et al. (1998) argued that this pattern of data supports the notion that negative reactivity is a temperamental trait and an antecedent in the development of behavioral inhibition. One of the i...

Citation Context

... a number of studies that have described the antecedents and developmental trajectories of behaviorally inhibited children. For example, Kagan, Reznick, Clarke, Snidman, and Garcia-Coll (1984) reported on 43 4-year-old children, 22 of whom were identified as inhibited at 21 months of age. At age 4, the 22 inhibited children were more socially inhibited with unfamiliar peers and more vigilant and hesitant during cognitive testing compared to the 21 children identified as uninhibited. At 5 years of age, the same 22 children were more inhibited with peers in both laboratory and school settings (Reznick et al., 1986). Kagan et al. (1987) subsequently reported on the original and a second cohort of children who were selected in either the second or third year of life as being behaviorally inhibited or uninhibited. At 6 years of age, the inhibited children continued to be more cautious and vigilant during their interactions with peers and with an experimenter and they exhibited signs of physiological stress. Yet it was the case that 40% of the inhibited children from these original groups became less inhibited by 5 years of age, while fewer than 10% of the children originally identified as uninhibited beca...

Citation Context

... period (Continuously Inhibited versus Change). The group that remained stable and inhibited exhibited right frontal asymmetry. The group that changed exhibited left frontal asymmetry by 14 months of age. This asymmetry pattern was evident at nine and 14 months of age. Although there were no differences in frontal asymmetry at 24 months, there was a trend toward a similar difference in frontal asymmetry between groups when children were 4 years of age. The right frontal EEG pattern observed in the continuously inhibited group is similar to previous findings with infants (Davidson & Fox, 1989; Fox, Bell, & Jones, 1992), children (Fox et al., 1996), and adults (Davidson, 1992; Schmidt & Fox, 1994). Prior studies with infants suggested that those infants exhibiting right frontal EEG asymmetry may be predisposed to express negative affect when confronted with a novel, mildly stressful situation. The EEG measures brain electrical activity recorded from different scalp locations. The precise source generators of the EEG are not certain. Thus, claims regarding relations between differences among individuals in regional brain electrical activity must be conservative with regard to actual differences in neural loc...

Citation Context

...of right frontal EEG asymmetry may serve as a marker of an underlying disposition rather than simply reflecting current affective state. For example, Davidson (1992) has argued that this EEG pattern reflects a diathesis around which stressful events may trigger the expression of negative affect or depressive symptomatology. In addition to being related to specific affective states, Fox and his colleagues have found relations between EEG asymmetry and shyness in adults and reticence in children. Specifically, adults who rated themselves as high in shyness displayed right frontal EEG asymmetry (Schmidt & Fox, 1994). Preschool and elementary school age children who displayed social reticence in a peer situation were more likely to display right frontal EEG asymmetry as well (Fox et al., 1995; Fox et al., 1996). And Calkins et al. (1996) reported that infants displaying high motor arousal and negative affect at four months of age were more likely to display right frontal EEG activity at nine months of age and behavioral inhibition at 14 months of age. A recent study by Schmidt et al. (1999) illustrates these relations. Seven-year-old children, observed to be shy in a peer situation, exhibited right fronta...

Citation Context

...ith ablation of selected brain regions within this circuit (Davis, 1992; Davis, Hitchcock, & Rosen, 1987). Based on these findings, Kagan argued that infants’ motor and affective reactions to novelty might reflect activity in this fear circuit. Specifically, infants exhibiting high degrees of motor arousal and negative affect in response to novelty may do so because of an over-activated fear circuit. This over-activation would later be expressed in the form of behavioral inhibition to the unfamiliar during the toddler and preschool years. More recent work of Davis and colleagues (Davis, 1998; Davis & Lee, 1998) has suggested, however, that areas immediately outside the amygdala (specifically the bed nucleus) may be associated with nonconditioned fear and perhaps this neural center may have an important role in anxiety rather than fear. Irrespective of whether the neural circuits underlying inhibition are through the amygdala or bed nucleus, it is interesting to note that outputs from either lead to changes in autonomic, neurendocrine, and behavioral/motor responses which have a parallel to the findings in behavioral inhibition work with human infants and children. Of significance to this study was t...

Citation Context

...ences in EEG power may indeed reflect regional patterns of neural activation. Of interest are recent studies (Davidson & Irwin, 1999) utilizing functional MR1 neuroimaging technology that have found a reciprocal relation between amygdala activity and prefrontal activation. These studies suggest that prefrontal activation inhibits the amygdala in response to stimuli designed to elicit negative affect. The amygdala is a structure in the limbic system implicated in conditioned fear responses (Davis, 1992). Greater amygdala activation has been associated with the potentiation of conditioned fear (Davis, Hitchcock, & Rosen, 1987). Thus, individual variation in the degree to which prefrontal activity inhibits amygdala may be critical for the inhibition or lack of inhibition of fear behaviors. Kagan and his colleagues have suggested that the temperamental origins of behavioral inhibition may be related to the excitability of certain areas of the amygdala, specifically the central nucleus (Kagan & Snidman, 1991). This hypothesis is based in part on those animal studies in which this area has been identified as part of the ―fear circuit‖ (LeDoux, 1987). Specifically, animals that were conditioned with a light and electri...

Citation Context

...th a novel, mildly stressful situation. The EEG measures brain electrical activity recorded from different scalp locations. The precise source generators of the EEG are not certain. Thus, claims regarding relations between differences among individuals in regional brain electrical activity must be conservative with regard to actual differences in neural location and activity. Nonetheless, recent research from Davidson’s laboratory would seem to support the adequacy of the EEG in reflecting neural activity and the role of prefrontal cortex in emotion. In a recent paper, Davidson and coworkers (Larson et al., 1998) report a significant correlation between glucose metabolism and EEG activity suggesting that differences in EEG power may indeed reflect regional patterns of neural activation. Of interest are recent studies (Davidson & Irwin, 1999) utilizing functional MR1 neuroimaging technology that have found a reciprocal relation between amygdala activity and prefrontal activation. These studies suggest that prefrontal activation inhibits the amygdala in response to stimuli designed to elicit negative affect. The amygdala is a structure in the limbic system implicated in conditioned fear responses (Davis...

Citation Context

...l years. In an attempt to examine infant predictors of behavioral inhibition, Kagan and colleagues selected infants at 4 months of age who displayed either high or low levels of motor arousal and negative affect in response to a series of novel visual and auditory stimuli (Kagan & Snidman, 1991). One-third of the high reactive infants were inhibited at either 14 or 21 months of age. In contrast, very few infants who were selected based on their low levels of reactivity were inhibited at later ages. High reactive infants also showed greater sympathetic reactivity than did low reactive infants (Snidman, Kagan, Riordan, & Shannon, 1995). In a follow-up of these selected infants, 46% of the children who had been high reactive at 4 months of age were classified as inhibited at 41/2 years of age (Kagan, Snidman, & Arcus, 1998). In contrast, only 10% of children who had been low reactive as infants were classified as inhibited. Thirteen percent of the high reactive infants seen at 41/2 years of age had been consistently inhibited at each of the assessment points over the 4-year period. Sixty-seven percent of the low reactive children, but only 27% of the high reactive children, were classified as uninhibited with peers. Kagan e...

Citation Context

...parately for the eyes-closed and eyesopened conditions. Again, power in the 6–8 Hz band was computed by summing the single hertz bins in the three frequencies. The use of different frequency bands at the different ages reflects observed developmental changes in the EEG. Specifically, at 9 months of age the majority of power was localized to the 4–6 Hz frequency range, while at older ages there was a clear shift in the locus of power to 6–8 Hz. Previous research with human infants has documented this shift in spectral power across the first years of life (Fox & Bell, 1990; Schmidt & Fox, 1998; Stroganova, Orekhova, & Posikera, 1999). The data used in analyses were the log power data from both the frontal and parietal regions, as well as laterality scores that were computed for each region at each age. Power and activation are thought to be reciprocally related (Davidson, 1988; Lindsley & Wicke, 1974). High power reflects low activation at a particular electrode site while low power reflects high activation. Laterality scores (ln right–ln left) are used to reflect the relative power in the right and left hemispheres. A positive score reflects greater R-power (or increased L-activation), whereas a negative score reflects ...

Citation Context

...creased resting right frontal EEG activation was associated with adults’ self-reports of higher levels of global negative affect (fear, disgust, sadness, and anger) while watching film clips selected to elicit negative emotions (disgust, sadness, and anger). The relation between resting frontal asymmetry and selfreported negative affect was particularly strong for the subjects’ ratings of fear. In contrast, resting frontal asymmetry was not related to the adults’ ratings of global positive affect (happiness, amusement, and interest) when viewing film clips selected to elicit positive emotion. Davidson and Fox (1989) found that 10-month-old infants who cried during a 1-minute period of maternal separation showed significant right frontal asymmetry during a baseline recording that took place before the mother left the room. In contrast, infants who did not cry during the separation period displayed significant left frontal asymmetry during the baseline recordings. In a separate study, Fox, Bell, and Jones (1992) replicated this finding and found the frontal EEG pattern to be stable across the second half of the first year of life. Henriques and Davidson (1990, 1991) reported that adults with clinical depre...

Citation Context

...ower in the 6–8 Hz band was computed separately for the eyes-closed and eyesopened conditions. Again, power in the 6–8 Hz band was computed by summing the single hertz bins in the three frequencies. The use of different frequency bands at the different ages reflects observed developmental changes in the EEG. Specifically, at 9 months of age the majority of power was localized to the 4–6 Hz frequency range, while at older ages there was a clear shift in the locus of power to 6–8 Hz. Previous research with human infants has documented this shift in spectral power across the first years of life (Fox & Bell, 1990; Schmidt & Fox, 1998; Stroganova, Orekhova, & Posikera, 1999). The data used in analyses were the log power data from both the frontal and parietal regions, as well as laterality scores that were computed for each region at each age. Power and activation are thought to be reciprocally related (Davidson, 1988; Lindsley & Wicke, 1974). High power reflects low activation at a particular electrode site while low power reflects high activation. Laterality scores (ln right–ln left) are used to reflect the relative power in the right and left hemispheres. A positive score reflects greater R-power (o...

Citation Context

...(1996) reported findings from the Australian Temperament Project in which they assessed 501 children longitudinally, beginning at 4 to 8 months of age and continuing through 5 to 6 years of age. The authors found few relations among the measures of inhibition from the infancy period to later ages. However, the magnitude of the correlations increased significantly when continuity was examined between the second year of life and 5 to 6 years of age. Rubin et al. (1999) reported moderate continuity in both mothers’ and fathers’ ratings of shyness among Canadian children from 2 to 4 years of age. Broberg (1993) also reported modest continuity in maternal reports of behavioral inhibition in a sample of Swedish first-born children assessed at 16, 28, and 40 months of age. Scarpa, Raine, Venables, and Mednick (1995) reported modest continuity in behavioral inhibition based on a longitudinal study of 1,800 Mauritian children assessed at 3, 8, and 11 years of age. The children were classified as high, middle, or low in inhibition at each of the three ages based on a combination of parental reports and behavioral observations. Children who were highly inhibited at 3 years of age displayed greater inhibiti...

Citation Context

...icke, 1974). High power reflects low activation at a particular electrode site while low power reflects high activation. Laterality scores (ln right–ln left) are used to reflect the relative power in the right and left hemispheres. A positive score reflects greater R-power (or increased L-activation), whereas a negative score reflects greater L-power (or increased Ractivation). Observed behavioral inhibition. At 14 and 24 months, the infant’s reactions to unfamiliar stimuli in the laboratory were coded to provide an index of behavioral inhibition (see Calkins et al., 1996; Kagan et al., 1987; Reznick, Gibbons, Johnson, & McDonough, 1989). At 14 months, the unfamiliar stimuli consisted of (1) an unfamiliar room/ environment, (2) an adult stranger, and (3) a novel toy/ object. At 24 months, the infant was presented with identical stimuli, and in addition, the infant’s reactions to an adult stranger dressed in a clown costume were recorded, as well as his /her willingness to crawl through an inflatable tunnel when encouraged to do so by the experimenter. At the beginning of the visit, the infant and mother entered an unfamiliar playroom with some toys on the floor. Mothers were instructed to work on questionnaires and to let in...

Citation Context

...l of their unpredictability in social situations. The change in the nature of the eliciting stimulus conditions from inanimate and social situations to social situations specifically warrants the introduction of different terminology for the behaviors in older children. Fox and Rubin have used the term social reticence to reflect behavioral inhibition in social situations. They and their colleagues have conducted detailed observations of children’s behaviors during free play, speech-making, and cooperative tasks with unfamiliar peers in order to study social reticence (e.g., Fox et al., 1996; Rubin, Coplan, Fox, & Calkins, 1995). Using a variety of observational taxonomies, including the Play Observation Scale (Rubin, 1989), these researchers have derived a measure of socially wary, anxious, and reticent behaviors in the preschool play group. This measure, comprising observed reticence and anxiety during free play and an inclination to avoid making a speech in the presence of unfamiliar peers, has been found to be contemporaneously associated with maternal reports of both dispositional shyness and internalizing behavior problems (e.g., Coplan, Rubin, Fox, & Calkins, 1994). In contrast, other forms of nonsocial play ...

Citation Context

... band was computed separately for the eyes-closed and eyesopened conditions. Again, power in the 6–8 Hz band was computed by summing the single hertz bins in the three frequencies. The use of different frequency bands at the different ages reflects observed developmental changes in the EEG. Specifically, at 9 months of age the majority of power was localized to the 4–6 Hz frequency range, while at older ages there was a clear shift in the locus of power to 6–8 Hz. Previous research with human infants has documented this shift in spectral power across the first years of life (Fox & Bell, 1990; Schmidt & Fox, 1998; Stroganova, Orekhova, & Posikera, 1999). The data used in analyses were the log power data from both the frontal and parietal regions, as well as laterality scores that were computed for each region at each age. Power and activation are thought to be reciprocally related (Davidson, 1988; Lindsley & Wicke, 1974). High power reflects low activation at a particular electrode site while low power reflects high activation. Laterality scores (ln right–ln left) are used to reflect the relative power in the right and left hemispheres. A positive score reflects greater R-power (or increased L-activat...

Citation Context

...in emphasis from assessment of reactivity to novel stimuli to assessment of the child’s social response to unfamiliar peers reflects the type of stimulus situation expected to elicit behavioral inhibition in older children. Older children are unlikely to display inhibition to novel objects but are likely to exhibit inhibition to novel social situations. This may reflect the child’s increasing perceived control over the nonsocial environment. Unfamiliar objects may elicit inhibition in infants and young children because of their novelty and the child’s lack of control over their actions (e.g., Gunnar, 1978, 1980). As children enter preschool they have more experience with a range of novel and unfamiliar toys and their perceived control over these objects may increase as well. In contrast, peers and adults may continue to elicit inhibition due to the level of their unpredictability in social situations. The change in the nature of the eliciting stimulus conditions from inanimate and social situations to social situations specifically warrants the introduction of different terminology for the behaviors in older children. Fox and Rubin have used the term social reticence to reflect behavioral inhi...

Citation Context

...are derived from the measure by taking the mean ratings on all items in the particular scale, omitting the items marked as ―Does not apply.‖ Of particular interest in this study were the scales ―Fear‖ (distress and extended latency to approach intense or novel stimuli), and ―Smiling and Laughing.‖ The Fear scale has 16 items with an internal consistency alpha of .84. The Smiling and Laughing scale has 15 items with an internal consistency alpha of .73 (Rothbart, 1981). At 14 and 24 months, maternal reports of temperament were gathered using the Toddler Behavior Assessment Questionnaire (TBAQ; Goldsmith, 1987, 1996). The TBAQ is a 111-item parent rating form in which parents are asked to rate the frequency of specific behaviors as they occurred in the past month. The TBAQ is modeled after the 1BQ and uses a similar response format in which parents rate the frequency of specific behaviors using a 7-point Likert-type scale. As on the 1BQ, there is an eighth option for ―Does not apply.‖ Six scale scores are created from the measure by taking the mean of items for a particular scale, omitting all items answered with ―Does not apply.‖ Of particular interest in this study were the scales Social Fearfuln...