Nelson, M., Clifton, R., Dowd, J., & Field, T. (1978). Cardiac responding
to auditory stimuli in newborn infants: Why pacifiers should not be used
when heart rate is the major dependent variable. Infant Behavior and Development,
1, 277 290.
• The present study examined heart rate responses of 16 awake newborns
to a 72 db auditory stimulus presented at four different times in relation
to ongoing nonnutritive sucking activity: just before a sucking burst, early
in a burst, late in a burst, and just after a burst. In addition, heart
rate changes were examined during an intertrial sucking burst of selected
duration. Intertrial results indicated that rapid, 10 bpm heart rate accelerations
and decelerations occurred at the onset and offset of nonnutritive sucking,
respectively. Heart rate changes in relation to tones were either acceleratory
or deceleratory, depending on the nature of ongoing sucking activity. The
results indicated that precise cardiac somatic coupling may occur in the
newborn, and that future studies of neonatal heart rate responding should
avoid the use of pacifiers to control state.
__________
Field, T. (1979). Visual and cardiac responses to animate
and inanimate faces by young term and preterm infants. Child Development,
50, 188 194.
• Infants' looking and looking-away behaviors, as well as cardiac
responses to mothers' spontaneous and imitative and to dolls' animated and
still faces, were recorded for 18 term and 18 preterm infants when they
were 3 months old. Infants spent less time looking at their mothers' than
at the doll's faces, and their heart-rate levels were elevated while looking
at mothers' faces. These effects were most pronounced for the preterm infants
whose inferior scores on the animate visual item of the Brazelton neonatal
scale suggested a continuity of visual inattentiveness to animate stimuli.
Both groups also looked at the inanimate more than the animate doll's face
and evidenced lower heart-rate levels during that situation.
__________
Field, T. (1979). Differential behavioral and cardiac responses
of 3 month old infants to a mirror and peer. Infant Behavior and Development,
2, 179 184.
• Behavioral and cardiac responses were assessed for 3-month-old infants
placed face-to-face with a mirror and peer. Infants looked longer at the
mirror, but smiled, vocalized, reached toward and squirmed more in the presence
of an infant peer. In addition, tonic heart rate was elevated during the
peer situation. These effects may relate to the peer situation being more
stimulating or arousing. Differential responding to the mirror and peer
suggests some very early awareness of differences between a self-image and
another infant.
__________
Field, T., Dempsey, J., Hatch, J., Ting, G., & Clifton,
R. (1979). Cardiac and behavioral responses to repeated tactile and auditory
stimulation by preterm and term neonates. Developmental Psychology, 15(4),
406 416.
• Auditory stimuli and a tactile stimulus were repeatedly presented
to 18 term and 18 preterm infants. Both groups initially responded to all
stimuli with increased limb movements and heart rate acceleration. However,
only the term infants responded to stimuli repetition by decreasing both
cardiac and behavioral responses. In addition, they differentially responded
to the three stimuli and showed response recovery in both systems. Since
a behavioral response decrement was observed without a cardiac response
decrement in the preterm group a second experiment was conducted. Heart
rate change during the sucking activity of Experiment 2 revealed an integration
between autonomic and motor responsivity of preterm infants comparable to
that of newborns.
__________
Field, T., & Walden, T. (1982). Production and discrimination
of facial expressions by preschool children. Child Development, 53, 1299
1311.
• Production and discrimination of the 8 basic facial expressions
were investigated among 34 3-5-year-old preschool children. Adults' "guesses"
of the children's productions as well as the children's guesses of their
own expressions on videotape were more accurate for the happy than afraid
or angry expressions and for those expressions elicited during the imitation
conditions. Greater accuracy of guessing by the adult than the child suggests
that the children's productions were superior to their discriminations,
although these skills appeared to be related. Children's production skills
were also related to sociometric ratings by their peers and expressivity
ratings by their teachers. These were not related to the child's age and
only weakly related to the child's expressivity during classroom free-play
observations.
__________
Field, T., Woodson, R., Greenberg, R., & Cohen, D. (1982).
Discrimination and imitation of facial expressions by neonates. Science,
218(8), 179 181.
• Human neonates discriminated three facial expressions (happy, sad,
and surprised) posed by a live model as evidenced by diminished visual fixation
on each face over trials and renewed fixations to the presentation of a
different face. The expressions posed by the model, unseen by the observer,
were guessed at greater than chance accuracy simply by observing the face
of the neonate, whose facial movements in the brow, eyes, and mouth regions
provided evidence for imitation of the facial expressions.
__________
Walden, T., & Field, T. (1982). Discrimination of facial
expressions by preschool children. Child Development, 53, 1312 1319.
• This study investigated preschool children's ability to discriminate
and categorize facial expressions. Children were shown drawings of persons
with expressions of joy, sadness, surprise, and anger and asked to choose
from an array of drawings the face that felt "the same" as the
standard. In some cases the match had identical facial features and in others
the match was a generalized version with no identical features. Both with
and without prompts children made fewer errors matching happy expressions
and matched generalized happy expressions as accurately as identical expressions.
Surprised and angry faces were less accurately matched. Providing verbal
labels for the faces facilitated matching, particularly for happy and generalized
expressions, suggesting that labeling or explicitly providing a conceptual
category may aid comparison and/or memory of the expressions. A levels-of-processing
effect is suggested to be operating in young children's discrimination and
categorization of facial expressions.
__________
Field, T., Woodson, R., Cohen, D.,Greenberg, R., Garcia, R.,
& Collins, K. (1983). Discrimination and imitation of facial expressions
by term and preterm neonates. Infant Behavior and Development, 6, 485 489.
• 48 term and preterm neonates participated in this study. The habituation/
dishabituation data of this study suggest that the neonate is capable of
discriminating at least happy, sad, and surprised facial expressions. Habituation
and dishabituation was more pronounced in term than preterm infants. However,
both groups of infants appeared to imitate components of the expressions
being modeled, and their expressions were accurately guessed more frequently
than would be expected by chance.
__________
Field, T., Cohen, D., Garcia, R., & Greenberg, R. (1984).
Mother stranger face discrimination by the newborn. Infant Behavior and
Development, 7, 19 25.
• Newborn infants discriminate their mother's face from the face of
a stranger shortly after birth. The neonates showed an initial preference
for their mother's face. The mother's face (or face and voice) was then
presented to the neonates for repeated trials until the infant reached an
habituation criterion. In a subsequent discrimination test the infants looked
significantly longer at the stranger's face, suggesting that the mother's
face was discriminated after very limited experience. Although voice cues
were not required for this discrimination, the possibility remains that
other cues, such as the mother's odor, may facilitate the discrimination
of her face.
__________
Field, T., Guy, L.,& Umbel, V. (1985). Infants' responses
to mothers' imitative behaviors. Infant Mental Health Journal, 6, 40 44.
• This study investigated whether infants smile and vocalize more
frequently subsequent to maternal imitative than non-imitative behavior
during both spontaneous and imitative face-to-face interactions. Fourteen
3-month old infants and their mothers were videotaped in these two face-to-face
interaction situations. The infants vocalized more frequently during the
imitative situation and infant vocalizations plus simultaneous smiling,
and vocalizations occurred more often following maternal imitative than
non-imitative behavior. Although these data suggest that infant vocalizations
and simultaneous smiles and vocalizations may reflect the infants’
recognition of maternal imitative behavior, they do not establish definitively
that it is the imitation per se vs. the contingency aspect that is recognized
by the infant.
__________
Field, T., Goldstein, S., Vega Lahr, N., & Porter, K.
(1986). Changes in imitative behavior during early infancy. Infant Behavior
and Development, 9, 415 421.
• Changes in imitative behavior and attentiveness were observed in
40 infants when they were 2 to 6 months of age. The facial expressions happy,
sad, and surprised were modeled in a trials-to-criterion procedure, and
the infants' looking time and mouth movements were recorded by an observer
who was unaware of the face being modeled. In addition, the observer recorded
her guess as to the expression being modeled by the corresponding expression
on the infant's face and rated the infant's expressivity. The results suggested
that looking time, correspondence between the mouth expression of the infant
and the mouth expression modeled, accuracy of the observer's guess, and
expressivity ratings decreased from 2 to 3 and 4 to 6 months. Although matching
of mouth movements with the modeled mouth movements and accuracy of guesses
were greater than chance over the 2 to 6 month-period, the decreases in
these measures suggest that imitative behavior declined across early infancy.
The decrease in looking time suggests that imitative behavior and attentiveness
may be related and highlights the limitation of this paradigm for assessing
the development of imitation during early infancy.
__________
Field, T. (1989). Individual and maturational differences
in infant expressivity. New Directions for Child Development, 44, 9-23.
• Young infants can discriminate among different facial expressions.
However, individual differences exist in infants' expressivity and ability
to produce and discriminate facial expressions. The greater concordance
between monozygotic than dizygotic twins on looking times and expressivity
suggest that individual differences in expressivity occur as early as birth,
possibly due to genetic differences.The significant individual differences
between high- and low-expressive infants on attentiveness, responsivity
to social stimulation, and automonic reactivity suggest that neonates may
differ on a broader dimension than simply their expressivity and highlight
the complexity of individual differences in neonatal behavior. Expressivity,
or some other more cornplex dimension such as extraversion, may be innate,
as has been speculated by Jones (1960) and Eysenck (1967), suggesting that
there may be continuity on this dimension.
__________
Walden, T., & Field, T. (1990). Preschool children's social
competence and production and discrimination of affective expressions. British
Journal of Developmental Psychology, 8, 65 76.
• This study investigated the relationship between the ability to
discriminate and produce facial expressions and social acceptance by peers
of young preschool children. Results indicated that abilities to discriminate
and produce expressions were unrelated when the contribution of age and
IQ to the relation was removed. Furthermore, posed and spontaneous productions
of expressions were not related. No gender differences were observed on
any measures. Thus, results indicate that children’s discriminations
ability and spontaneous expressivity predict social competence, as indexed
by; liking by peers.
__________
Pickens, J., Field, T., Nawrocki, T., Martinez, A., Soutullo,
D. & Gonzalez, J. (1994). Full-term and preterm infants' perception
of face-voice synchrony. Infant Behavior and Development, 17, 447-455.
• This study investigated auditory-visual matching of faces and voices
by preterm versus full-term infants at 3, 5, and 7 months of age. A significantly
higher rate of visual fixation to the sound-matching films was observed
in the full-term 3- and 7-month groups, but not at 5 months. Longitudinal
testing confirmed the U-shaped developmental curve for full-term infants'
task performance. In contrast to full terms, preterm infants did not display
evidence of detecting face-voice synchrony. This suggests that an auditory-visual
matching deficit may be associated with infant prematurity.
__________
Lundy, B., Field, T., Cigales, M., Cuadra, A.,& Pickens,
J.,(1997). Vocal and facial expression matching in infants of mothers with
depressive symptoms. Infant Mental Health Journal, 18, 265-273.
• This study investigated vocal and facial expression matching in
24 10-month-old infants. Half of the mothers had reported depressive symptoms
during the previous week. Infants of mothers who reported depressive symptoms
displayed less accurate matching of the happy facial and vocal expressions
and looked more to sad facial expressions compared to infants of mothers
who had not reported depressive symptoms above the normal range. Infants'
performance on the expression matching task appears to be related to their
primary caregivers' reports of depressive symptoms during the previous week.
However, other factors that may be related to the group differences also
need to be considered. For example, maternal reports of depressive symptoms
may be a marker for other underlying factors that may have affected their
infants' performance.
__________
Field, T., Pickens, J., Fox, N., Gonzalez, J. & Nawrocki
(1998). Facial expressions and EEG responses to happy and sad faces/voices
by 3-month-old infants of depressed mothers. British Journal of Developmental
Psychology, 16, 485-494.
• Videotaped happy and sad face/voice stimuli were presented after
a neutral starfield baseline stimulus to 24 3-month-old infants of depressed
and non-depressed mothers. The infants looked at and showed more positive
expressions during the happy and sad face/voice stimuli versus the neutral
starfield. The infants of non-depressed versus depressed mothers looked
at the sad face/voice stimulus longer, perhaps because the sad face/voice
stimulus was more novel for the infants of non-depressed mothers. A negative
correlation between EEG and visual fixation time suggested that less left
frontal activation (usually associated with withdrawal) was related to greater
visual fixation time (usually associated with approach behaviour). This
mixed approach/ withdrawal response was observed more frequently in infants
of non-depressed mothers and could be interpreted as a vigilant or empathetic
response in those infants.
__________
Hart, S., Field, T., Del Valle, C., & Letourneau, M. (1998).
Infants protest their mothers' holding an infant-size doll. Social Development,
7, 54-61.
• 76 Twelve-month old infants experienced 4 situations of unresponsiveness
in which their mothers and a stranger directed positive attention toward
a doll or a picture book while they ignored the infant. Infants demonstrated
more protest, negative vocalizations and inhibited play during the doll
condition, particularly if the doll was held by the mother. Infant contacts
with the mother were more frequent when the mother held the doll. Infants'
distress during the mother/doll condition was interpreted as jealousy.
__________
Hart, S., Field, T., Letourneau, M., & DelValle, C.(1998).
Jealousy protests in infants of depressed mothers. Infant Behavior and Development,
21, 137-148.
• Twelve-month-old infants of (N=97) mothers reporting depressed and
nondepressed symptoms were videotaped while their mothers and a stranger
directed positive attention toward a book or a doll while they ignored the
infant. During conditions of unresponsiveness in which the object of attention
was a doll, infants of depressed versus nondepressed mothers demonstrated
less protest behavior, less proximity to their mothers, less disturbed exploratory
activity and greater proximity to a stranger.
__________
Hernandez-Reif, M., Field, T., Del Pino, N., & Diego,
M. (2000). Less exploring by mouth occurs in newborns of depressed mothers.
Infant Mental Health Journal, 21, 204-210.
• Twenty-four newborns of depressed and nondepressed mothers were
assessed for oral perception of a nubby and smooth texture. Both groups
of newborns discriminated between these textures and showed a sucking preference
for the smooth texture. However, the newborns of depressed mothers spent
50% less time orally exploring the stimuli, one-third less time exploring
the more novel nubby texture, and 59% less time mouthing the smooth texture.
Newborns of depressed mothers may have biological differences that affect
their emotional arousal and emotional regulation (e.g., capacity for self-soothing).
__________
Pickens, J., Field, T., Fox, N. & Nawrocki, T. (2001).
Frontal EEG Asymmetry in response to emotional vignettes in preschool age
children. International Journal of Behavioral Development, 25, 105-112.
• EEG recordings were conducted with preschool children during presentations
of videotaped vignettes depicting a fictional young child experiencing happy,
sad, angry, and fearful events. Significant EEG asymmetry in the frontal
region (left frontal activation) occurred during all types of emotional
vignettes, but not during baseline periods (a neutral star-field image presented
before and after each vignette). These children displayed mostly neutral
facial expressions during the vignettes, with some evidence of lip movements
during the negative episodes (suggesting that the stories were eliciting
some mild emotional responses or empathy). There was no evidence of more
intense emotional responses that have been associated with right frontal
cortical activation. These EEG patterns may reflect cortical mechanisms
underlying mild emotional responses and affective displays in preschool
children, as well as their developing ability to regulate their affective
systems.
Visual
__________
Hernandez-Reif, M., Field, T., Diego, M., & Largie, S.
(2002). Depressed mothers' newborns show inferior face discrimination. Infant
Mental Health Journal, 23, 643-653.
• Infants of depressed mothers took longer to habituate their mothers'
face/voice and afterwards displayed no visual preference for mother or stranger,
compared to infants of non-depressed mothers who showed a novelty preference
for stranger.
Aroma
__________
Fernandez, M., Hernandez-Reif, M., Field, T., Sanders, C.,
Diego, M., & Roca, A. (In Review ). EEG during lavendar and rosemary
exposure in infants of depressed mothers.
• Infants of depressed mothers exposed to rosemary or lavender oil
showed a shift in EEG toward greater relative left frontal asymmetry. This
shift was associated with an approaching pattern of behavior and response
to positive stimuli.
Temperature
__________
Hernandez-Reif, M., Field, T., Diego, M., and Largie, S. (In
Review). Oral temperature perception by newborns of depressed vs. non-depressed
mothers. Infant Behavior and Development.
• Newborns of depressed mothers sucked longer to cold and warm bottle-nipples
and showed no preference for one over the other.
__________
Hernandez-Reif, M., Field, T., & Diego, M. (2004). Differential
sucking by neonates of depressed versus non-depressed mothers. Infant Behavior
and Development,27, 465-476.
• Neonates of depressed and non-depressed mothers sucked on cold and
warm nipples on alternating trials. Neonates of depressed mothers sucked
twice as much as neonates of non-depressed mothers, suggesting arousal dysregulation,
overactivity or greater hedonic behavior in the newborns of depressed mothers.
__________
Hernandez-Reif, M., Field, T., Diego, M., and Largie, S. (2002).
Haptic habituation to temperature is slower in newborns of depressed mothers.
Infancy,4,47-63.
• Infants of depressed and non-depressed mothers were habituated to
a cold or warm temperature tube by hand. Infants of depressed mothers 1)
required twice as long to habituate, 2) showed a sensitization effect, indexed
as an increase in holding from the second to the third trial of habituation
and 3) showed passive hand activity while holding the object in their hand.
_______________________________________________________________________________________
Texture
Hernandez-Reif, M., Field, T., del Pino, N., and Diego. M.
(2000). Less Exploring by mouth occurs in newborns of depressed mothers.
Infant Mental Health Journal, 21, 204-210.
• Newborns of depressed mothers spent half as much time orally exploring
a nubby and smooth texture orally, suggesting that they may have biological
differences affecting their emotional arousal and regulation.
Weight
__________
Hernandez-Reif, M., Field, T., Diego, M., and Largie, S. (2002).
Weight perception by newborns of depressed vs. non-depressed mothers. Infant
Behavior and Development, 24, 305-316.
• Newborns of depressed mothers showed passive manipulation of objects
and did not detect a change in the object's weight during test trials.
__________
Fernandez, M., Blass, E.M., Hernandez-Reif, M., Field, T.,
Sanders, C., & Diego, M. (2003). Sucrose attenuates a negative EEG response
to an aversive stimulus for newborns. Journal of Developmental and Behavioral
Pediatrics, 24, 261-266.
• Reports that sweet taste calms crying in newborns and is analgesic
against the pain caused by a heel lance served as the basis for this study.
In a randomized and controlled trial, 34 newborns were administered 2 mL
of water or sucrose solution before the heelstroke. Infants who received
water showed increased relative right frontal EEG activation from baseline
to the post-heelstroke phase, a pattern that typifies negative affect. The
EEG of infants in the sucrose group did not change. Heart rate increased
rapidly in both groups during the heelstroke phase. However, after the heelstroke,
the heart rate of infants who received sucrose returned to baseline, whereas
the heart rate of infants who tasted water remained elevated. During the
heelstroke, the infants in the water group cried and grimaced twice as long
as the infants in the sucrose group. These findings add to the growing literature
showing that sucrose attenuates newborns' negative response to aversive
or noxious stimuli.
__________
Hernandez-Reif, M., Field, T., Diego, M., & Largie, S.
(2003). Haptic habituation to temperature is slower in newborns of depressed
mothers. Infancy, 4, 47-63.
• Forty newborns of depressed and nondepressed mothers were habituated
to a cold or warm temperature tube by hand. Both groups of infants habituated
the temperature of the tube, as indicated by a decrease in holding, and
dishabituated, as indexed by an increase in holding when the temperature
of the tube changed. However, the newborns of depressed mothers (a) required
twice as long to habituate; (b) showed a sensitization effect, as indexed
by an increase in holding from the second to the third trial of habituation;
and (c) passively handled the objects with their hand.
__________
Hernandez-Reif, M., Field, T., & Diego, M. (2004). Differential
sucking by neonates of depressed versus non-depressed
mothers. Infant Behavior and Development,27, 465-476.
• Forty-two neonates of depressed and non-depressed mothers sucked
on cold and warm nipples on alternating trials. Half the infants received
the cold nipple on the first of the eight trials and the other half received
the warm nipple first. Neonates of depressed mothers sucked twice as much
as neonates of non-depressed mothers, suggesting arousal dysregulation,
overactivity or greater hedonic behavior in the newborns of depressed mothers.
Although the newborns did not show a preference for cold or warm nipples,
a temperature order effect revealed that neonates who received the cold
nipple on the first trial sucked significantly more on trials 2–8
than those who received the warm nipple on the first trial, suggesting that
an initially cold nipple might elicit greater sucking.
__________
Field, T., Hernandez-Reif, M., Vera, Y., Gil, K., Diego, M.,
& Sanders, C. (2005). Infants of depressed mothers facing a mirror versus
their mother. Infant Behavior and Development, 28, 48-53.
• Behavioral responses were assessed in 3-6-month-old infants of depressed
mothers placed face-to-face in front of a mirror versus in front of their
mother. Infants showed more positive behavior (smiling) with their mothers
versus the mirror but also showed more negative behavior (gaze aversion,
distress brow and crying) during the mother condition. These differences
highlight the infants' greater affective responses (both positive and negative)
to their mother versus the mirror. Equivalent amounts of vocalizing to the
mother and mirror suggested that the mirror does elicit social behavior,
with the infants perhaps enjoying watching themselves talk. Group differences
suggested that the infants of depressed mothers showed less gaze aversion
with their mothers, perhaps because their mothers were less interactive.
When in front of the mirror, they vocalized more and gaze averted less than
the infants of non-depressed mothers, suggesting that the mirror was particularly
effective in eliciting vocalizations in infants of depressed mothers.
__________
Hernandez-Reif, M., Diego, M., & Field, T. (2006). Instrumental
and vocal music effects in neonates of depressed and non-depressed mothers.
Infant Behavior and Development., 29, 518-525.
• Neonates of non-depressed mothers showed greater relative right
frontal EEG asymmetry to both types of music, suggesting a withdrawal response.
Neonates of depressed mother on the other hand, showed greater relative
left frontal EEG asymmetry to the instrumental without vocal segment, suggesting
an approach response, and greater relative right frontal EEG asymmetry to
the instrumental with vocal segment, suggesting a withdrawal approach.
__________
Hernandez-Reif, M., Field, T., Diego, M., & Ruddock, M.
(2006). Greater arousal and lesser attention by neonates of depressed vs
non-depressed mothers on the brazelton neonatal assessment scale. Infant
Behavior and Development, 29, 594-8.
• The neonates of depressed mothers received lower scores on orienting
to the live face/voice stimulus and on the alertness items, suggesting they
were less attentive. They also scored less optimally on the cuddliness and
hand-to-mouth activity items, suggesting they were more aroused.
__________
Hernandez-Reif, M., Field, T., Diego, M., Vera, Y., &
Pickens, J. (2006). Happy faces are habituated more slowly by infants of
depressed mothers. Infant Behavior & Development., 29, 131-35.
• Infants of depressed mothers took longer to habituate the video
clips of facial expressions compared to infants of non-depressed mothers,
and those assigned to habituate the sad video clips displayed a novelty
response or dishabituated to the happy expressions.
__________
Field, T., Diego, M., Hernandez-Reif, M. & Fernandez,
M. (2007). Depressed mothers’ newborns show less discrimination of
other newborns’ cry sounds. Infant Behavior and Development, 30, 431-5.
• The newborns of non-depressed mothers responded to the cry sounds
of other infants with reduced sucking and decreased heart rate. In contrast,
the newborns of depressed mothers did not show a change in their sucking
or heart rate to the cry of other infants. This lesser responsiveness to
other infants’ cries may predict a lack of empathy.
__________
Field, T., Hernandez-Reif, M., Diego, M., Feijo, L., Vera,
Y., Gil, K., & Sanders, C. (2007). Responses to animate and inanimate
faces by infants of depressed mothers. Early Child Development and Care,
177, 533-539.
• Forty infants of depressed mothers and non-depressed mothers were
seated in an infant seat and were exposed to four different degrees of animation,
including a still-face Raggedy Ann doll, the same doll in an animated state
talking and head-nodding, an imitative mother and a spontaneously interacting
mother (the more animate mother condition). The infants spent more time
looking at the doll, but they smiled and laughed more at the mother. The
infants of depressed versus non-depressed mothers showed less laughing and
more fussing when their mothers were spontaneously interacting, but showed
more laughing and less fussing during the mother imitation condition. Paradoxically,
the infants of non-depressed mothers were negatively affected by the imitation
condition, showing less smiling and laughing and more fussing than they
had during the spontaneous interactions.
__________
Lundy, B., Field, T., Carraway, K., Hart, S., Malphurs, J.Rosenstein,
M., Pelaez-Nogueras, M., Coletta, F., & Hernandez-Reif, M. (1998).Food
texture preferences in infants. Early Child Development and Care, 146, 69-85.
• In the present research, infants displayed more negative expressions,
negative head movements and negative body movements when presented with
more complex textures. In contrast, toddlers showed more positive head and
body movements and more eagerness for complex textures. The data also suggest
that experience with difficult-to-chew textures can facilitate a preference
for a more complex texture.
