50cercetare
TRANSCRIPT
-
7/29/2019 50cercetare
1/12
Cogniie, Creier, Comportament / Cognition, Brain, Behavior
Vol. IX(3), 317-328, 2005Romanian Association of Cognitive Sciences
INDIVIDUAL DIFFERENCES IN THE DEVELOPMENT
OF SOCIAL COMMUNICATION:
JOINT ATTENTION AND TEMPERAMENT
Kate E. NICHOLS*, Jennifer N. MARTIN, Nathan A. FOX
University of Maryland, USA
ABSTRACT
Social communication is an important skill that emerges during infancy. Weexamined individual differences in this skill as a function of temperament andneural activity in nine-month-old infants. We found that maternal ratings oftemperament were associated with joint attention, an important index of early
social communication. More specifically, maternal ratings of pleasure wereassociated with joint attention bids that were accompanied by positive affect,while maternal ratings of fearfulness were associated with joint attention bidsthat were accompanied by negative affect. We also found that initiating jointattention was associated with decreased left frontal electroencephalogram(EEG) power, and initiating behavioral requests were associated with
decreased left frontal EEG power.
KEY-WORDS:joint attention, affect, temperament, EEG, social
communication
Infants communicate with social partners for many reasons. Some forms of
social communication may emerge out of an intrinsic motivation system as
described in models of intersubjectivity development (Trevarthen & Hubley,
1978). Infants who are high in approach may have a lower threshold for
experiencing reward and may more easily elicit and display positive affect during
social communication. In contrast, infants who are temperamentally fearful, high in
avoidance or withdrawal motivation, may be less inclined to interact socially with
unfamiliar persons, and more likely to communicate with familiar others as a way
of maintaining contact in unfamiliar situations. Little research has investigated the
associations between infant temperament or motivational bias and the developmentof social communication. The current study sought to address this issue by
assessing relations between temperament and social communication in infants.
Infants are able to communicate from an early age through eye contact and
gestures. By nine-months, the neural circuitry of the basal ganglia and the
*Corresponding address:
Kate E. Nichols,University of Maryland, 3304 Benjamin Bldg, College Park, MD 20742Email: [email protected]
-
7/29/2019 50cercetare
2/12
Iunie 2005 Cogniie, Creier, Comportament318
substantia nigra are established well enough to allow for the inhibition of reflexiveorienting responses, the initiation of purposeful goal-driven saccades, and the
maintenance of focused attention on objects of interest to the child (Johnson,
1990). Shifting gaze, particularly in a meaningful or voluntary fashion, is thought
to substantially influence an infants ability to explore their environment and to
participate in early forms of social communication (Butcher, Kalverboer, & Geuze,
2000).
According to Bates (1976) early social communication is comprised of
protodeclarative and protoimperative acts. Protodeclarative acts describe instances
where an infant uses eye contact or gestures to spontaneously begin a period of
coordinated attention with a social partner. On the other hand, protoimperative acts
describe instances where an infant uses eye contact or gestures to elicit aid in
obtaining an object or modifying an event. Recently, Mundy and colleagues(Seibert, Hogan, & Mundy, 1982; Mundy et al., 2003) have developed a procedure
for eliciting these different acts of communication with infants in the second half of
the first year of life and into the second year of life. The procedure, called the Early
Social Communication Scale (ESCS; Mundy, et al., 2003) provides a context in
which both protodeclarative acts (referred to as Initiating Joint Attention; IJA) and
protoimperative acts (referred to as Initiating Behavioral Requests; IBR) may be
observed. Individual differences in IJA have been associated with varying levels of
social and language development, and in particular, deficits in IJA have been
related to autism (Carpenter, Nagell, & Tomasello, 1998; Mundy, Sigman,
Ungerer, & Sherman, 1986).
Temperament can be thought of as the disposition of the infant to react or
respond with a particular emotion to novel or unfamiliar stimuli. Vaughn andcolleagues (2003) have found that infant temperament, as assessed by measures of
positive and negative reactivity on the Rothbart Infant Behavior Questionnaire
(IBQ, Rothbart, 1981), is related to IJA. The association between the bias to
express positive affect and joint attention is consistent with the idea that IJA
involves sharing experiences with others in a positively valenced interaction
(Mundy, 1995; Mundy & Sigman, in press), and that IJA is intrinsically motivated
by a neural system for engaging in shared awareness (Trevarthen & Hubley, 1978).
It has also been suggested that the basic motivational system for engaging in
episodes of shared awareness with others develops in two stages (Trevarthen &
Hubley, 1978). The first stage, primary intersubjectivity, involves systems that
promote social attention, including the ability to respond to eye contact and facial
affect. Through interactions during this stage infants are provided with experiences
that allow them to represent self as distinct from other. When infants experience
the same affect as their social partner, it motivates them to continue the interaction,
especially when the experience is positive. With increased interactions and
cognitive maturation the infant becomes capable of the second stage, namely
secondary intersubjectivity, or awareness that both self and others are sharing an
experience (Trevarthen & Hubley, 1978). These experiences lead the infant to
initiate more periods of shared attention. In general, research has shown that IJA,
-
7/29/2019 50cercetare
3/12
Iunie 2005 Cogniie, Creier, Comportament 319
as compared to IBR, is more often accompanied by positive affect (Adamson &Bakeman, 1985; Mundy, Kasari, & Sigman, 1992). This supports the hypothesis
that when infants share mutual eye contact and attention on a common object, they
find it rewarding. Furthermore, autistic children rarely experience positive affect
while sharing attention with a social partner (Kasari, Sigman, Mundy, & Yirmiya,
1990), which may mean that children with autism are less likely to engage in joint
attention for an inherent social reward (Mundy, 1995). Thus failure to assign
reward value to social stimuli has been proposed as a possible explanation for
autism (Dawson, Osterling, Rinaldi, Carver, & McPartland, 2001; Dawson et al.,
2001).
In the current study we investigated individual differences in the frequency
of IJA accompanied by positive or negative affect in relation to infant temperament
in a typically developing sample. We hypothesized that infants with a positivetemperament will exhibit IJA accompanied by positive affect while infants with a
fearful temperament will exhibit IJA accompanied by negative affect will be most
prevalent in infants with a fearful temperament. In support of this notion, Vaughn
and colleagues (2003) suggest that IJA may be associated with a vigilant or wary
style of attention. This interpretation is in line with the hypothesis that the fear
system is related to increased vigilance and orienting to environmental cues that are
threatening or novel (LeDoux, 2000).
Another area that has linked negative reactivity and social contact seeking
is the attachment literature. Bowlby (1969) first conceived attachment as a stress-
related biobehavioral system that was the key system involved in maternal
bonding. Attachment theory suggests that the system is activated in response to
threat and stress. Negative reactivity may result from increased threat responses,which in turn may result in increased signals for social connection and comfort. De
Laguna (1927) has suggested that both language and nonverbal forms of
communication, such as eye contact in humans (Scheflen, 1963) and grooming in
non-human primates, (Dunbar, 1991) are, at their most basic level, strategies for
developing and maintaining social relationships. Locke (2001) suggests that many
infant vocalizations and gestures, including joint attention, are analogous to the
Testing. Testing. vocalization used when an adult tests a microphone system.
The voice and shared attention offers a means of maintaining continuous contact
with key figures in the infants social world. However, little research has
investigated the affective quality of communication that is motivated by negative
reactivity and vigilance. At the physiological level, positive reactivity and negative
reactivity have been linked to differences in frontal brain systems. Within the first
year of life, social motivation, social orienting, positive affect, and approach
behaviors have been associated with left frontal EEG activity, and greater relative
right frontal EEG activation has been associated with crying in response to a brief
period of maternal separation and behavioral inhibition (Fox, 1991; Fox &
Davidson, 1987; Davidson & Rickman, 1999; Fox, Henderson, Rubin, Calkins, &
Schmidt, 2001).
-
7/29/2019 50cercetare
4/12
Iunie 2005 Cogniie, Creier, Comportament320
These EEG lateralization differences have also been studied in associationwith IJA. Mundy, Card, and Fox (2000) studied typically developing infants from
14 to 18 months and found that EEG power in the alpha band in left but not right
frontal sites was associated with IJA. The authors suggested that the left frontal
EEG activation associated with IJA may reflect individual differences in approach
tendencies. However, other research (Henderson, Yoder, Yale, & McDuffie, 2002)
suggests that both right and left frontal EEG power is associated with IJA. These
data are consistent with data from Vaughan et al. (2003) that suggests that IJA may
also be associated with negative affect and motivation tendencies that have been
related to relative right frontal EEG activation (Mundy & Sigman, in press).
In the current study, we investigated infant temperament, joint attention,
and left and right frontal EEG power. Affect was coded during the ESCS procedure
in order to examine the relations between affective expression and socialcommunication in infancy. Parents also completed a standard infant temperament
questionnaire in order to assess the role of maternal report of infant temperament
on early social communication skills. We had three hypotheses: first, it was
expected that positive affect would accompany joint attention more than behavioral
requests. Second, we anticipated that mothers ratings of infant temperamental
fearfulness would be associated with initiating joint attention bids accompanied by
negative affect. Third, we expected that frontal EEG power would vary in
accordance with the different affective measures of IJA and IBR.
Method
Participants. Infants were classified based on their 4-month observed
behavioral reactivity scores and assigned to one of two different temperament
groups: fearful or exuberant . The fearful group was high in motor and negative
reactivity (n = 88), and the exuberant group was high in motor and positive
reactivity (n = 66). An unselected sample was also recruited and served as a control
group (n = 96). At 9 months, all three groups of infants returned to the laboratory
and IJA and IBR were assessed with the Early Social Communication Scale
(ESCS; Mundy, Hogan, & Doehring, 1996). Maternal report of temperament was
collected using the Infant Behavior Questionnaire (IBQ; Rothbart, 1981).
Measures
Early Social Communication Scale. Data on nonverbal joint attention and
requesting behaviors were collected with the revised Early Social CommunicationScales (ESCS; Mundy et al. 2003). The ESCS is a structured assessment designed
to measure the development of nonverbal communication skills in infants and
toddlers during the 6- to 30-month age period. The experimenter and child, in his
or her mothers lap, are seated facing each other across a table for a series of
activities involving mechanical and windup toys. Seven toys were presented across
21 trials.
Observations of the experimenter-toddler interactions yielded scores for
joint attention and behavioral requests. Initiating Joint Attention (IJA) describes the
-
7/29/2019 50cercetare
5/12
Iunie 2005 Cogniie, Creier, Comportament 321
raw number of times the toddler alternated eye contact between the activemechanical toys and the tester, pointed to the toys, or showed the toys in order to
share the experience with the tester. Initiating Behavior Requests (IBR) describes
the number of times the toddler reached for a mechanical toy beyond his/her grasp,
spontaneously gave a toy to the experimenter, or made eye contact with the
experimenter after a mechanical toy had stopped in order to elicit aid from the
tester. Two coders became reliable with 19 cases on the ESCS training tape, IJA
alphas = .81 and .91, IBR alphas = .87 and .93. The coders rated an additional 25
cases from the sample. Alphas for total IJA, neutral IJA, total positive IJA, low
intensity positive IJA, high intensity positive IJA, and negative IJA were .98, .85,
.90, .85, .92, and .90 respectively. Alphas for total IBR, neutral IBR, total positive
IBR, low intensity positive IBR, high intensity positive IBR, and negative IBR
were .95, .94, .81, .84, .95, and .79 respectively.EEG data collection. At 9 months, each infant was seated in his or her
mothers lap to minimize fussiness and movement. They watched a metal bingo
wheel placed on a table in front of them, where an experimenter placed 1, 3, or 7
brightly colored balls and spun the wheel for six trials each lasting 20 s and
separated by 10-s intervals. Prior to recording EEG for each infant, a 50 V Hz
signal calibration signal was input into each of the channels, amplified, and
recorded. The infants head was measured in order to select an appropriate sized
Lycra stretch cap with electrodes for EEG recording sewn into the fabric according
to the 1020 system of electrode placement (Jasper, 1958). In order to ensure that
the cap stayed in place during recording, elastic straps on each side of the cap were
attached to a chest strap.
A small amount of Omni-Prep gel was inserted into each of the active (F3,F4, F7, F8, Fz, C3, C4, P3, P4, Pz, O1, O2, T7 and T8) and referenced sites (CZ)
and then each site was gently abraded with a blunt end of a Q-tip. Next a small
amount of electrolyte gel was inserted and the Q-tip was used to ensure contact
with the scalp. Impedances were measured at each site and were considered
acceptable if they were below 10 K ohms.
One channel of electrooculogram (EOG) was recorded from the left eye
using two Beckman mini-electrodes, one placed at the supra orbit, and the second
at the outer canthus position. EEG and EOG were amplified with a high pass
setting at .1 Hz and a low pass setting at 100 Hz on custom bio-amplifiers made by
SA Instrumentation. The EEG data were digitized at a rate of 512 Hz throughout
the experiment and then re-referenced using software that analyzed the data with
using the average reference configuration. The digitized data were then displayed
graphically for artifact scoring. Portions of EEG marked by movement artifact
were removed from all channels of the EEG record prior to further analysis. The
blinks were regressed out of the portions of EEG marked with eye movement.
The re-referenced, artifact-scored EEG data were submitted to discrete
Fourier transform analysis and power in picowatt ohms (or microvolts squared) for
each channel was computed. Spectral power data in single Hz frequency bids from
130 Hz were computed for each of the stimulus conditions at each of the
-
7/29/2019 50cercetare
6/12
Iunie 2005 Cogniie, Creier, Comportament322
collection sites. Power in the 69 Hz frequency band was computed for each siteby summing the single hertz bins in these four frequencies for each stimulus
condition. The 6-9 Hz band was utilized since this band for 9 month olds is thought
to reflect alpha like activity (Marshall, Hardin, & Fox, 2005). The data used in the
analyses were the log power data from the frontal regions (F3 and F4). Activation
and power in the Alpha band are thought to be reciprocally related (Davidson,
1988), where high power reflects low activation and low power reflects high
activation.
Maternal report of infant temperament. Mothers were asked to complete
an infant report of temperament using the Infant Behavior Questionnaire at 9
months (IBQ; Rothbart, 1981). The IBQ is an 87-item parent report that asks
parents to rate the frequency of behaviors using a 7- point scale. The scales used in
this study were the Fear (distress and extended latency to approach novel orintense stimuli), and Smiling and Laughing scales.
Results
We conducted multiple analyses in order to study the relations of early
social communication, temperament, and frontal power. For means and standard
deviations see Table 1 and for correlations see Table 2. Only those children who
received at least 14 of the possible 21 trials were included in the analysis. Sixteen
children had an inadequate number of trials (3 exuberant children, 4 fearful
children, and 9 control children) and therefore were not included in the analysis.
Table 1. Descriptive Statistics
Table 2. Correlations between Initiating Joint Attention and Initiating Behavioral Requests
Mean SD n
IJA total 0.92 0.46 203
IJA positive 0.21 0.22 203
IJA neutral 0.69 0.42 203
IJA negative 0.02 0.05 203
IBR total 0.55 0.30 203
IBR positive 0.09 0.12 203
IBR neutral 0.45 0.28 203
IBR negative 0.01 0.04 203
Pleasure 5.05 0.78 190
Fearfulness 2.60 0.71 189
IJA IJA IJA IJA IBR IBR IBR IBR
Total Pos Neutral Neg Total Pos Neutral Neg
IJA total 1.00
IJA positive 0.39 * 1.00
IJA neutral 0.87 * -0.10 1.00
IJA negative 0.17 * -0.06 0.09 1.00
IBR total 0.13 0.07 0.11 -0.01 1.00
IBR positive 0.03 0.46 * -0.21 * -0.02 0.32 * 1.00
IBR neutral 0.12 -0.13 0.21 * -0.03 0.90 * -0.10 1.00
IBR negative 0.01 -0.02 -0.01 0.25 * 0.19 * 0.00 0.07 1.00
-
7/29/2019 50cercetare
7/12
Iunie 2005 Cogniie, Creier, Comportament 323
n = 203; * p < .05First we investigated whether positive affect was more likely to accompany
joint attention than behavioral requests. We calculated the percentage of IJA bids
that were accompanied by positive affect and the percentage of IBR bids that were
accompanied by positive affect and compared them in a paired sample t-test.
Positive affect was significantly more likely to accompany joint attention than
behavioral requests (t(1,201)=4.501,p < .001).
Next we investigated whether maternal report of pleasure and fearfulness
was correlated with joint attention. As a preliminary analysis, we investigated
whether there were any differences in maternal report of temperament at 9 months
between the 4-month temperament groups in an ANOVA. No differences were
found for pleasure ratings (F(2,187) = .271, ns) and fearfulness ratings (F(2,186) =
.862, ns). Therefore, we combined the temperament groups in the subsequentanalysis. The ratio of joint attention and behavioral request bids was used because
the total number of segments was related to the number of joint attention and
behavioral request bids. We found that fearfulness ratings were related to total IJA
bids (r= .204,p < .01, n = 189), neutral IJA bids (r= .145,p < .05, n = 189), and
negative IJA bids (r= .177,p < .05, n = 189). We also found that pleasure ratings
were related to positive IJA bids (r = .166, p < .05, n = 189). There were no
significant relations between IBR and maternal report of pleasure or fearfulness.
In addition, wee also investigated whether frontal activation was related to
IJA and IBR (see Table 3). We predicted total IJA at 9 months in a model with left
frontal power (6 to 9 Hz) and right frontal power (6 to 9 Hz). The model with left
frontal power was significant (F(1,160) = 4.089,p < .05; (= .158, t(159) = 2.022,p < .05). The model with left and right frontal power was also significant (F(2,159)
= 3.944, p < .05). Only the main effect for left frontal power was significant (=
.37, t(159) = 2.754, p < .01). None of these relations were significant when
predicting positive or neutral IJA attempts.
Predicting Initiating Behavioral Requests
Variable R Adj-R p
Step 1 (df 1/160) 0.006 0.000
Left Frontal Power -0.081
Step 2 (df 2/159) 0.025 0.012
Left Frontal Power -0.271 0.05
Right Frontal Power 0.233
Table 4. Predicting Initiating Behavioral Requests
Predicting Initiating Joint Attention
Variable R Adj-R p
Step 1 (df 1/160) 0.025 0.019 0.05
Left Frontal Power 0.158 0.05
Step 2 (df 2/159) 0.047 0.035 0.05
Left Frontal Power 0.369 0.01
Right Frontal Power -0.259
Table 3. Predicting Initiating Joint Attention
-
7/29/2019 50cercetare
8/12
Iunie 2005 Cogniie, Creier, Comportament324
To assess whether frontal activation was related to IBR (see Table 4) we
predicted total IBR at 9 months in a model with left frontal power (6 to 9 Hz) and
right frontal power (6 to 9 Hz). The model with left frontal power was not
significant. The model with left and right frontal power was also not significant.
However, the main effect for left frontal power (= -.27, t(159) = -1.998,p < .05)
was significant. There were no significant relations for predicting positive or
neutral IBR.
Discussion
The major goal of this study was to describe how reactivity relates to early
social communication. Infants who are temperamentally fearful may be more likelyto initiate joint attention because they are more vigilant while infants who are
temperamentally positive may be more likely to initiate joint attention because they
have positive experiences that they want to share with a social partner. In our
investigation of these processes we took into account the affective quality of each
initiating joint attention or behavioral request bid.
Our findings suggest positive affect is more likely to accompany joint
attention than behavioral requests, and that differences in temperament are
associated with the display of joint attention that varies in affective valence. When
we investigated maternal report of temperament we found associations with IJA
but not with IBR. Vaughn et al. (2003) also found that IJA, but not IBR, was
related to maternal report of pleasure and fearfulness. One explanation for this
finding is that mothers may base their temperament ratings on salient moments of
their interactions with their infants (Hane, Fox, Polak-Toste, Ghera, & Guner,
under revision). Periods of shared attention may be particularly salient instances of
a mothers time with her infant. More specifically, we found that infants who were
rated as more fearful at 9 months initiated more joint attention. When the affective
quality of the IJA bid was considered, IJA bids accompanied by both negative and
neutral affect were related to maternal report of fearfulness while IJA bids
accompanied by positive affect were related to maternal report of pleasure.
Interestingly, when we analyzed frontal power in our sample, IJA was
associated with left frontal hypoactivation and greater right activation. Although
this finding is inconsistent with previous EEG findings, which have suggested a
greater relation between joint attention and left frontal activation, the results are inaccordance with an emerging notion that IJA may be more strongly associated with
negative affect and cautious motivation tendencies, particularly in younger infants.
The display of negative affective motivation tendencies associated with relative
right frontal activation is also logical within the particular methodology used to
examine joint attention skills in this experiment. Specifically, the ESCS paradigm
in this study examined IJA and IBR behaviors that occurred between the infant and
a relatively unfamiliar adult. One can concede that this version of the paradigm
may naturally lend itself to the observation of more vigilant behaviors with the
-
7/29/2019 50cercetare
9/12
Iunie 2005 Cogniie, Creier, Comportament 325
infant alternating focus between the novel object and the novel adult, especially ifthe infant is high in negative reactivity.
These frontal activation patterns can also be considered in the framework
of their connections with other neural regions. In particular, the developing
prefrontal cortex is known to have connections with limbic regions including the
amygdala, which is the predominant structure associated with affective functions.
A significant amount of research has highlighted the role of the amygdala in
emotional processes (LeDoux, 1996), and especially in the context of fear
conditioning (LeDoux, 1993). Recently, Davidson (2004) has suggested that the
prefrontal cortex may play a primary role in inhibiting amygdala activity. This
region may both inhibit the amygdala and moderate activity in parts of the neural
circuit that control affective responses. This notion fits well with our finding that
IJA in 9-month-olds was associated with greater right activation and presumablydecreased inhibition of the amygdala. Furthermore, this explanation becomes more
plausible when one considers that a substantial amount of attention we observed
may be more closely related to information seeking or vigilance instead of
information sharing. Lastly, when we investigated the role of frontal power with
just those instances of joint attention that were accompanied by positive, neutral, or
negative affect, no relations between frontal sites and IJA were found.
With regards to IBR, our findings indicate a frontal power pattern opposite
of that found in IJA with left frontal activation. This result suggests that IBR are
related to approach tendencies, which is consistent with prior neural activation
findings of greater left frontal activation in association with approach behaviors
(Davidson & Rickman, 1999; Fox, 1991; Fox & Davidson, 1987; Fox et al., 2001).
The underlying circuitry of approach behaviors has been put forth in a variety ofneuroanatomical models, most of which reference the prominent role of dopamine
transmission and corresponding states of appetitive motivation (Depue & Collins,
1999; Derryberry & Rothbart, 1997).
Despite the seemingly disjointed patterns found between frontal power in
IJA and in IBR, the results may actually help to clarify our understanding of
attention skills that contribute to, or facilitate, the development of social
communication. For instance, IJA and IBR are unique components of social
communication, each of which develops in a slightly different manner (Mundy et
al, 2000; Nichols, Fox, & Mundy, 2005). However, the question remains as to
whether, or in what manner, IJA and IBR mutually influence each other in the
progression of social abilities.
Several limitations are worth noting. In these analyses highly reactive
children were over sampled and thus the findings are most generalizable to highly
reactive infants. Another limitation involves the frequency that negative and
positive bids were observed. Instances of negatively toned IJA were rare, and
therefore, caution should be used when interpreting the findings. Future studies
should continue to investigate individual differences in emotional reactivity and
frontal brain systems in order to better understand how they relate to the
development and expression of early social behavior.
-
7/29/2019 50cercetare
10/12
Iunie 2005 Cogniie, Creier, Comportament326
REFERENCES
Adamson, L. B., & Bakeman, R. (1985). Affect and attention: Infants observed withmothers and peers. Child Development, 56, 582-593.
Bates, E. (1976).Language and context: The acquisition of performatives. New York, NY:Academic Press.
Bowlby, J. (1969).Attachment and Loss. Vol 1. Attachment,New York: Basic Books.Butcher, P.R., Kalverboer, A.F., & Geuze, R.H. (2000). Infants shifts of gaze from a
central to a peripheral stimulus: A longitudinal study of development between 6 and26 weeks.Infant Behavior & Development, 23, 3-21.
Carpenter, M., Nagell, K., & Tomasello, M. (1998). Social cognition, joint attention, andcommunicative competence from 9 to 15 months of age.Monographs of the Society
for Research in Child Development, 63, (4, Serial No. 255).
Davidson R. J. (1988). EEG measures of cerebral asymmetry: Conceptual andmethodological issues.International Journal of Neuroscience, 39, 71-89.
Davidson, R. J. (2004). What does the prefrontal cortex "do" in affect: Perspectives onfrontal EEG asymmetry research.Biological Psychology, 67, 219-233.
Davidson, R. J., & Rickman, M. (1999). Behavioral inhibition and the emotional circuitry
of the brain: Stability and plasticity during the early childhood years. In L. A.Schmidt & J. Schulkin (Eds.), Extreme fear, shyness, and social phobia: Origins,biological mechanisms, and clinical outcomes. (pp. 67-87): Oxford University Press.
Dawson, G., Osterling, J., Rinalidi, J., & Carver, L., and McPartland, J. (2001). Briefreport: Recognition memory and stimulus-reward associations: Indirect support forthe role of the ventromedial prefrontal dysfunction in autism. Journal of Autism andDevelopmental Disorders, 31, 337-341.
Dawson, G., Toth, K., Abbott, R., Osterling, J., Munson, J., Estes, A., et al. (2004). Early
Social Attention Impairments in Autism: Social Orienting, Joint Attention, andAttention to Distress.Developmental Psychology, 40, 271-283.
De Laguna, G. A. (1927). Speech: Its function and development. New Haven, Ct: YaleUniversity Press.
Derryberry, D. & Rothbart, M.K. (1997). Reactive and effortful processes in theorganization of temperament.Development and Psychopathology, 9, 633-652.
Depue, R.A. & Collins, P.F. (1999). Neurobiology of the structure of personality:Dopamine, facilitation of incentive motivation, and extraversion. Behavioral andBrain Sciences, 22, 491-569.
Dunbar, R. I. (1991). Functional significance of social grooming in primates. FoliaPrimatologica, 57, 121-131.
Fox, N. A. (1991). If it's not left, it's right: Electroencephalograph asymmetry and thedevelopment of emotion.American Psychologist, 46, 863-872.
Fox, N. A., & Davidson, R. J. (1987). Electroencephalogram asymmetry in response to theapproach of a stranger and maternal separation in 10-month-old infants.Developmental Psychology, 23, 233-240.
Fox, N. A., Henderson, H. A., Rubin, K. H., Calkins, S. D., & Schmidt, L. A. (2001).
Continuity and discontinuity of behavioral inhibition and exuberance:Psychophysiological and behavioral influences across the first four years of life.
Child Development, 72, 1-21.Hane, A. A., Fox, N., Polak-Toste, C., Ghera, M., & Guner, B. (under revision). The
contextual basis of maternal perceptions of infant temperament: The role of mother-
-
7/29/2019 50cercetare
11/12
Iunie 2005 Cogniie, Creier, Comportament 327
infant home-based interactive affect in the relation between maternal report andobserver ratings of infant temperament.
Henderson, L., Yoder, P., Yale, M., & McDuffie, A. (2002). Getting the point:Electrophysiological correlates of protodeclarative pointing.International Journal ofDevelopmental Neuroscience, 20, 449 - 458.
Johnson, M.H. (1990). Cortical maturation and the development of visual attention in early
infancy.Journal of Cognitive Neuroscience, 2, 81-95.Kasari, C., Sigman, M., Mundy, P., & Yirmiya, N. (1990). Affective sharing in the context
of joint attention interactions of normal, autistic, and mentally retarded children.Journal of Autism and Developmental Disorders, 20, 87-100.
LeDoux, J. E. (1993). Emotional memory systems in the brain. Behavioural BrainResearch, 58, 69-79.
LeDoux, J. E. (1996). The emotional brain: The mysterious underpinnings of emotional
life. New York: Simon & Schuster.LeDoux, J. E. (2000). Emotion circuits in the brain. Annual Review of Neuroscience, 23,
155-184.Locke, J. L. (2001). First communication: The emergence of vocal relationships. Social
Development, 10, 294-308.
Marshall, P.J., Hardin, M.G., & Fox, N.A. (2005). Electrophysiological responses toauditory novelty in temperamentally different 9-month-old infants. Submitted
Mundy, P. (1995). Joint attention and social-emotional approach behavior in children withautism.Development and Psychopathology, 7, 63-82.
Mundy, P., Card, J., & Fox, N. (2000). EEG correlates of the development of infant jointattention skills.Developmental Psychobiology, 36, 325-338.
Mundy, P., Delgado, C., Block, J., Venezia, M., Hogan, A., & Seibert, J. (2003). A Manual
for the Abridged Early Social Communication Scales (ESCS). Available through the
University of Miami Psychology Department, Coral Gables, Florida([email protected]).
Mundy, P., Hogan, A., & Doehring, P. (1996).A preliminary manual for the abridged earlySocial Communication Scales (ESCS). Retrieved April 10, 2002, from University ofMiami-Coral Gables, Psychology Department. Website:
http://www.psy.miami.edu/child/pmundyMundy, P., Kasari, C., & Sigman, M. (1992). Joint attention, affective sharing, and
intersubjectivity.Infant Behavior and Development, 15, 377-381.Mundy, P. & Sigman, M. (in press) Joint Attention, Social Competence and Developmental
Psychopathology. In D. Cicchetti and D. Cohen (Eds.), Developmentalpsychopathology (2nd edition). Volume I: Theory and methods, Hoboken, N.J.:
Wiley.Mundy, P., Sigman, M., Ungerer, J., & Sherman, T. (1986). Defining the social deficits of
autism: The contribution of nonverbal communication measures. Journal of ChildPsychology and Psychiatry, 27, 657-669.
Nichols, K., Fox, N., & Mundy, P. (2005). Joint attention, self-recognition andneurocognitive functioning.Infancy, 7, 35-52.
Rothbart, M. (1981). Measurement of temperament in infancy. Child Development, 52,569-578.
Scheflen, A. E. (1963). Communication and regulation in psychotherapy., Psychiatry:Interpersonal & Biological Processes, 26, 126-136.
Seibert, J. M., Hogan, A. E., & Mundy, P. C. (1982). Assessing interactional competencies:The Early Social Communication Scales.Infant Mental Health Journal, 3, 244-245.
-
7/29/2019 50cercetare
12/12
Iunie 2005 Cogniie, Creier, Comportament328
Trevarthen, C. & Hubley, P. (1978). Secondary Intersubjectivity: Confidence, confidingand acts of meaning in the first year. In A. Lock (Ed.),Action, gesture, and symbols:The emergence of language (pp. 183-229). London: Academic Press.
Vaughan, A., Mundy, P., Block, J., Burnette, C., Delgado, C., & Gomez, Y. (2003). Child,caregiver and temperament contributions to infant joint attention. Infancy, 4, 603-616.