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The role of the efficiency of novel actions in infants’ goal anticipation

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In two experiments, we recorded infants' eye movements to test whether the efficiency of the action influences infants' ability to anticipate the outcome of an ongoing action performed by abstract figures. In Experiment 1, we found that predictive eye movements were elicited by both nonefficient and efficient actions, but anticipation of the outcome occurred much earlier in the efficient action condition. Experiment 2 was designed to test the effect of saliency of the goal and the possibility that automatic extrapolation of the movement was partly responsible for the predictive gaze shifts in Experiment 1. We found that when automatic extrapolation was prevented and the goal was not salient, infants showed predictive gaze shifts only in the efficient action condition. Taken together, our findings support the importance of teleological inferences in anticipating the goals of ongoing actions.
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The role of the efficiency of novel actions in infants’
goal anticipation
Szilvia Biro
Centre for Child and Family Studies, Department of Cognitive Psychology, Leiden Institute for Brain and Cognition,
Leiden University, 2333 AK Leiden, The Netherlands
article info
Article history:
Available online 30 November 2012
Keywords:
Infants
Goal anticipation
Action understanding
Eye tracking
Predictive eye movements
Teleological inferences
abstract
In two experiments, we recorded infants’ eye movements to test
whether the efficiency of the action influences infants’ ability to
anticipate the outcome of an ongoing action performed by abstract
figures. In Experiment 1, we found that predictive eye movements
were elicited by both nonefficient and efficient actions, but antici-
pation of the outcome occurred much earlier in the efficient action
condition. Experiment 2 was designed to test the effect of saliency
of the goal and the possibility that automatic extrapolation of the
movement was partly responsible for the predictive gaze shifts in
Experiment 1. We found that when automatic extrapolation was
prevented and the goal was not salient, infants showed predictive
gaze shifts only in the efficient action condition. Taken together,
our findings support the importance of teleological inferences in
anticipating the goals of ongoing actions.
Ó2012 Elsevier Inc. All rights reserved.
Introduction
The ability to anticipate the outcome of others’ ongoing actions allows us not only to attribute goals
to observed actions but also to prepare ourselves to interact with or, if necessary, to counteract others
before their actions are completed. Therefore, this capacity is undoubtedly useful, and its early
emergence is crucial for survival as well as for social learning (Csibra & Gergely, 2007; Tomasello,
Carpenter, Call, Behne, & Moll, 2005). Although several different mechanisms have been proposed
to be responsible for the development of the ability to identify the likely outcome and goal of an action
0022-0965/$ - see front matter Ó2012 Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.jecp.2012.09.011
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E-mail address: sbiro@fsw.leidenuniv.nl
Journal of Experimental Child Psychology 116 (2013) 415–427
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(Gergely & Csibra, 2003; Hommel, Musseler, Aschersleben, & Prinz, 2001; Rizzolatti, Fogassi, & Gallese,
2001), there is no consensus about their relative importance.
According to one of the theories on action interpretation, we use a teleological framework to attri-
bute goals (Gergely & Csibra, 2003). Thus, when we observe an action, we seek to establish a relation-
ship among three relevant aspects of current reality: the action, the outcome, and the physical
constraints of the situation. The teleological stance theory argues that an observed action will be inter-
preted as goal-directed only if the action can be considered as the most efficient means to achieve the
outcome under the current situational constraints. It is claimed that the application of this abstract
interpretational schema requires neither extensive experience with actions nor the ability to perform
them and that, therefore, it can be applied to interpret actions of a wide range of entities. Several stud-
ies have used the ‘‘violation of expectation paradigm’’ to test the application of the teleological frame-
work during infancy. The looking time patterns found in these studies suggest that infants from
around 6 to 9 months of age are able to rely on the efficiency
1
of both human and novel nonhuman
(robotic or self-propelled objects) actions to interpret the actions as goal-directed (Biro, Csibra, &
Gergely, 2007; Biro, Verschoor, & Coenen 2011; Csibra, Gergely, Biro, Koós, & Brockbank, 1999; Csibra,
2008; Csibra et al., 2003; Gergely, Nádasdy, Csibra, & Biro, 1995; Hernik & Southgate, 2012; Kamewari,
Kato, Kanda, Ishiguro, & Hiraki, 2005; Sodian, Schoeppner, & Metz, 2004; Southgate, Johnson, & Csibra,
2008; Verschoor & Biro, 2012; Woodward & Sommerville, 2000).
Furthermore, the teleological stance theory claims that the teleological interpretational system also
allows the generation of predictive inferences, including goal prediction. Thus, when we observe an
ongoing incomplete action, we can rely on the assumption of efficiency to infer an outcome that
can be justified under the given situational constraints. This hypothesized outcome can then be attrib-
uted as the goal of the action. Some studies suggest that from around 12 months of age, infants can
make inferences about the unseen goals of incomplete actions. For example, during the observation
of ‘‘chasing’’ events of abstract geometric figures or balls (Csibra et al., 2003; Southgate & Csibra,
2009; Wagner & Carey, 2005), infants were able to interpret the observed action as chasing and infer
the outcome that the chaser would catch up. However, the infants were able to do so only if the ob-
served ongoing action could be considered as an efficient means toward the hypothesized outcome
given the situational constraints.
Because the findings in all of these studies are based on duration of looking time measures, they
might be open to alternative interpretations. Indeed, it has been argued that these measures do not
necessarily reflect true predictions about the outcome; they could instead indicate retrospective infer-
ences. Infants could, in principle, have evaluated the efficiency of the action when they were presented
with the outcome during the test events rather than while they were watching the incomplete actions
during the habituation/familiarization phase (Gredebäck & Melinder, 2010; Southgate, Johnson,
Karoui, & Csibra, 2010).
Another (more direct) measure that has recently been used to investigate adults’ and infants’ abil-
ity to anticipate the outcome of observed ongoing actions is predictive eye gaze (Cannon & Woodward,
2012; Eshuis, Coventry, & Vulchanova, 2009; Falck-Ytter, Gredebäck, & von Hofsten, 2006; Flanagan &
Johansson, 2003; Gredebäck & Kochukhova, 2010; Gredebäck & Melinder, 2010; Gredebäck,
Stasiewicz, Falck-Ytter, Rosander, & von Hofsten, 2009; Kanakogi & Itakura, 2011; Kochukhova &
Gredebäck, 2010; Paulus et al., 2011). Falck-Ytter and colleagues (2006), for example, demonstrated
that 12-month-olds, but not 6-month-olds, show predictive eye movements when they observe a
human hand transferring balls to a basket; that is, they shift their gaze to the basket before the hand
arrives and drops the ball into the basket. However, predictive eye movements were not found in this
study when the balls moved to the basket by themselves without help from the hand. In this case, in-
fants followed the movement, but their gaze did not arrive at the basket ahead of the moving balls. The
authors argued that these findings suggest that predictive looking, and therefore goal anticipation of
ongoing actions, is restricted to human actions and that infants need to be able to perform the actions
themselves to anticipate the goals of similar actions by others. This argument supports the direct
1
In these studies, the evaluation of efficiency was based on various perceptual cues such as taking the shortest pathway,
exerting the least effort, and taking only causally necessary steps. Therefore, it has been suggested that the efficiency of the action
is applied as an abstract principle for representing actions during infancy (e.g., Csibra, Biro, Koós, & Gergely, 2003).
416 S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427
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matching hypothesis of action interpretation, which claims that the starting mechanism for under-
standing others’ goal-directed behavior is based on mapping the observed actions onto one’s own mo-
tor representation of those actions (Falck-Ytter et al., 2006; Fogassi et al., 2005; Gallese & Goldman,
1998). However, more recent studies have disputed the claim that predictive looks are exclusive to
human actions because predictive gazes were elicited from both adults and infants when they
watched actions without the involvement of human movement (Eshuis et al., 2009; Paulus et al.,
2011). On the other hand, because the actions in these studies were performed by toy or animated car-
toon animals, the ability to anticipate the likely outcome of these actions may have been partly due to
prior knowledge or expectations about the actions of the actors.
Two recent studies tested the effect of the efficiency of the action on the presence of predictive eye
movements. In Gredebäck and Melinder’s (2010) study, 12-month-olds observed human feeding sce-
narios in which a feeder either moved the food to the mouth of the partner (efficient action condition)
or placed the food onto the back of the hand of the partner, who then ate it from her own hand (nonef-
ficient action condition). Although infants showed predictive looks in both conditions (i.e., they fixated
on the partner’s head or hand before the food arrived), in the efficient action condition their predictive
looks occurred earlier (i.e., they anticipated faster) during the third repetition of the feeding action, sug-
gesting that the efficiency of the action has some influence on the timing of predictive looks. Further-
more, differences in pupil dilation between the two conditions also indicate that infants’ evaluated
the efficiency of the observed action. However, as the authors also pointed out, because the efficient ac-
tion was also more familiar than the nonefficient action, these differences in the two conditions may
have reflected infants’ reaction to the familiarity with the action rather than to the effect of efficiency.
In Paulus and colleagues’ (2011) study, 9-month-olds’ predictive looks were measured to test
whether infants are able to anticipate the most efficient, but novel, action of an agent (an animated
cow) to achieve its goal (catching up with a sheep) after the situational constraints had changed. In-
fants were found to shift their gaze to an area indicating that they anticipated the repetition of the
familiar, previously seen action rather than a novel but, in the new situation, more efficient route.
However, because the sheep walked off from the screen before the cow started to move, infants never
saw the goal state being attained. Therefore, it is possible that applying the principle of efficient action
to anticipate a novel action under new situational constraints toward an unseen goal state may have
been too challenging for 9-month-olds. Consistent with this possibility, previous looking time studies
suggest that 12-month-olds, but not 9-month-olds, are able to make predictive inferences using the
teleological schema, possibly because some background processes necessary for hypothesis formation
are too weak in 9-month-olds (see Csibra et al., 2003).
Therefore, the range of the types of actions, as well as the role of efficiency in goal anticipation
measured by predictive gaze, is still uncertain. The current study aimed to investigate whether predic-
tive gaze shifts are present and influenced by the efficiency of ongoing novel nonhuman actions. In-
fants were shown animations involving geometric figures in two conditions: an efficient action
condition and a nonefficient action condition. In both conditions, a blue circle could be categorized
as an agent on the basis of showing self-initiated and varied movements (Biro & Leslie, 2007; Luo &
Baillargeon, 2005; Tremoulet & Feldman, 2000). In the efficient action condition, infants watched
the blue circle approaching and making contact with a red circle by ‘‘jumping over’’ a rectangular fig-
ure located in between them (see Fig. 1). The nonefficient action condition was equivalent to the effi-
cient action condition except that the rectangular figure was not present. Thus, jumping could not be
considered as an efficient action toward the outcome (contacting the red circle). The animations were
repeated six times, but they differed slightly from each other in terms of the size of the obstacle and
the height of the blue circle’s jump, thereby providing additional support for the efficient adjustment
of the blue circle’s action to changing situational constraints in the efficient action condition and for
equifinally
2
varying movement in the nonefficient action condition (see also the ‘‘Stimuli’’ section
below).
2
It has been proposed that identifying the particular goal of an agent could be based on the equifinal structure of an action,
which comes from the observation that the agent’s different actions result in one and the same consequence (Heider, 1958).
However, it has been shown using looking time measures that without evidence for efficiency of the action, this cue is insufficient
to interpret the observed action as goal-directed (Csibra et al., 1999; Gergely et al., 1995).
S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427 417
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If the movement characteristics of a novel entity are sufficient to categorize it as a goal-directed
agent and to anticipate its goal (Baron-Cohen, 1994; Leslie, 1994; Premack, 1990), then predictive
gazes should be elicited in both conditions. If, on the other hand, infants can infer the goal of an ongo-
ing action only when it can be justified in the given environment, as predicted by the teleological
stance theory, then predictive gazes should be found only in the efficient action condition. Finally,
if infants can only anticipate the outcome of human actions, then predictive gazes should not be found
in any of the two conditions. Looking time studies suggest that goal prediction for ongoing incomplete
actions based on efficiency emerges at the end of the first year (Csibra et al., 2003). Therefore, we
tested a group of 13-month-olds.
Experiment 1
Methods
Participants
A total of 30 13-month-old infants (mean age = 397.2 days, SD = 18.44, range = 368–423, 14 boys
and 16 girls) participated in the experiment. An additional 6 infants also participated but were ex-
cluded due to a lack of reliable gaze data (see criteria for inclusion in the ‘‘Data analysis’’ section be-
low). Infants were randomly assigned to either the efficient action condition or the nonefficient action
condition. They were recruited through direct mail to their families and received a gift after the exper-
iment. Parents could opt to have their travel costs reimbursed.
Stimuli
Infants were presented with animated movies involving geometric figures (see Fig. 1).
3
Infants in
the efficient action condition saw a blue circle on the right side, a larger red circle on the left side,
and a black rectangular figure in the middle of the screen (Introduction scene, 300 ms). The blue circle
NON-EFFICIENT ACTION
EFFICIENT ACTION
Goal
Goal
Approach
Jump
Start
Approach
Jump
Start
Obstacle
Obstacle
Fig. 1. Illustration of the animation with the areas of interest analyzed in Experiment 1.
3
The stimuli in the two conditions were similar, but not identical, to the habituation stimuli used in Gergely et al. (1995) study.
418 S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427
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started to move along a straight path, stopped, moved back to its original position, and then started to
move again (Beginning scene, 3400 ms). It then took a parabolic path over the rectangular figure (Jump-
ing scene, 1300 ms). After landing, it moved toward the red circle (Approaching scene, 1000 ms) and
stayed in contact with it (Arriving scene, 600 ms). The animation lasted 6600 ms and was repeated six
times. The six animations were identical except that the size of the ‘‘jumping’’ movement of the blue cir-
cle varied according to the changing height of the rectangular figure (low, medium, or high). The order of
the animations was the same for all participants: low–medium–high–low–high–medium. Infants in the
nonefficient action condition saw the same animations except for the fact that the rectangular figure was
absent. The movement of the blue circle was the same. Thus, it varied its parabolic path in the same man-
ner and order as in the efficient action condition.
Procedure and apparatus
Infants sat in their caregivers’ laps in a curtained booth facing the Tobii T120x eye-tracker with an
integrated 17-inch TFT monitor. The height of the chair and the position of the monitor were adjusted
to establish a good eye-tracking status (so that infants’ eyes were 60 cm away from the monitor).
Using ClearView 2.7.1 software (Tobii Technology), first a 5-point infant calibration procedure was
carried out showing infants a blue–white pulsating circle with sound. A shaking duck image with
sound was shown as an attention-getting stimulus when infants looked away during calibration.
The presentation of the animations immediately followed the calibration. Caregivers were informed
about the procedure and were instructed to close their eyes, not to talk, and to try to keep their infants
from moving or leaning. After the experiment, the caregivers were shown the gaze replay of their in-
fants and were told the rationale of the study.
Data analysis
Five areas of interest (AOIs) were defined: Start, Jump, Obstacle (adjusted to its changing height
across trials), Approach, and Goal (see Fig. 1). Gaze was measured during all six animations. Data from
a given animation were included if there were a minimum of three fixations: one fixation in the Start
AOI during the Beginning scene, one fixation in the Jump AOI during the Jumping scene, and one fix-
ation in the Goal AOI that needed to follow the previous two fixations. This criterion was used to en-
sure that looking at the Goal AOI reflected anticipation based on seeing at least the start of the
jumping movement of the circle, which is presumably necessary to evaluate the efficiency of the ac-
tion. A fixation filter with a 50-pixel fixation radius and a 200-ms minimum fixation duration was
used (e.g., Gredebäck, Örnkloo, & von Hofsten, 2006). A participant was included in the analysis only
if data from a minimum of three animations (trials) could be obtained.
Gaze timing data. We calculated the difference between the time of infants’ fixation to the Goal AOI
and the arrival time of the blue circle in the Goal AOI (time difference) in each accepted trial. Thus,
predictive looks (positive time difference) and reactive looks (negative time difference) could be iden-
tified. For each participant, the average of the time differences of the accepted trials was also calcu-
lated. In addition, to investigate the effect of repetition of the animations while avoiding problems
with missing data and slight variations between the movies, the six trials were collapsed into two
blocks (i.e., the data from the first and last three trials were separately averaged, resulting in Blocks
1 and 2, respectively).
4
Furthermore, for each participant, we calculated the percentages of trials with
predictive and reactive looks and the distribution of predictive looks during the Jumping and Approach-
ing scenes. Finally, the number of fixations to the Goal AOI during the Beginning scene was also counted.
Looking time data. We computed the total looking time for each accepted trial. Furthermore, we also
calculated the ratios of looking times at the Goal, Jump, and Obstacle AOIs relative to the total looking
time as well as the looking times at the Jump AOI during the Jumping scene. (The looking time data
4
Note that if a given trial was not accepted, then the block was calculated from the remaining accepted trials. If all three trials
belonging to a block were missing, then that block was absent.
S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427 419
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were used to compare conditions as well as to test alternative explanations for differences between
the conditions in the presence and timing of predictive gaze shifts.)
Results
There was no difference in the number of accepted trials, the number of overall fixations, and the
mean total looking times between the two conditions, t(28) = 0.89, p= .37, t(28) = 0.86, p= .39, and
t(28) = 0.44, p= .66, respectively.
Gaze timing
Using one-sample ttests, first the average time differences were tested against 0. We found that
the time differences were significantly above 0 in both conditions: efficient action, t(15) = 5.84,
p< .001; nonefficient action, t(13) = 3.93, p= .002 (see Fig. 2). This indicates that infants in both con-
ditions showed predictive looking. To compare the two conditions, an independent-sample ttest was
carried out. It revealed a significant difference between the two conditions, t(29) = 2.09, p= .046,
indicating that infants showed earlier gaze shifts in the efficient action condition than in the noneffi-
cient action condition. A repeated-measures analysis of variance (ANOVA) was carried out with con-
dition as a between-participants factor and block as within-participant variable, including only infants
who had valid data in both blocks (13 in the nonefficient action condition and 14 in the efficient action
condition). Although a significant condition effect, F(1,25) = 6.05, p= .021,
g
2
p
¼:19, was again found,
there was no interaction between condition and block.
An independent-sample ttest showed that infants produced predictive looks in a significantly
higher percentage of trials in the efficient action condition (M= 86.25%) than in the nonefficient action
condition (M= 55.71%), t(28) = 3.46, p= .002. Paired-sample ttests also revealed that there was a sig-
nificantly higher percentage of trials with predictive looks than reactive looks in the efficient action
condition, t(15) = 7.77, p< .001, whereas there was no difference between the two types of looks in
the nonefficient action condition, t(13) = 0.73, p= .47. In the nonefficient action condition, a signifi-
cantly higher percentage of predictive looks occurred during the Approaching scene (M= 80.23%) than
during the Jumping scene (M= 19.76%), t(13) = 3.12, p= .008, whereas no difference was revealed in
the efficient action condition, t(15) = 1.39, p= .18. Finally, during the Beginning scene, there were
significantly more fixations to the Goal AOI in the efficient action condition (M= 2.68) than in the non-
efficient action condition (M= 1.35), t(28) = 2.87, p= .008.
Looking times
Independent-sample ttests showed no difference between the two conditions in the average look-
ing time ratios for the Goal AOI, t(28) = 0.33, p= .74, and for the Jump AOI, t(28) = 0.66, p= .51,
Fig. 2. Mean gaze arrival in the Goal AOI relative to the arrival of the blue circle in Experiment 1. Positive values imply that the
gaze arrived before the circle. (For interpretation of the references to color in this figure legend, the reader is referred to the web
version of this article.)
420 S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427
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relative to the total looking time or in the average looking time for the Jump AOI during the Jumping
scene, t(28) = 0.63, p= .63. Looking times for the Obstacle AOI were also analyzed. Even though the
obstacle was not present in the nonefficient action condition, there was no significant difference be-
tween the two conditions in looking time for the Obstacle AOI, t(28) = 1.77, p= .087. More important,
we found that only 1 infant in a single trial looked at the Goal AOI right after the infant looked at the
Obstacle AOI. Finally, because the age range was relatively wide, the gaze timing and looking time
analyses were also carried out using the age (in days) of the infants as a covariate whenever this
was possible. All of the effects remained the same, suggesting that age had no effect on the fixations.
Discussion of Experiment 1
We investigated whether the efficiency of an ongoing novel action influences the presence and tim-
ing of predictive gazes of 13-month-olds. We found that infants in both the efficient and nonefficient
action conditions showed predictive eye movements; that is, they shifted their gaze to the outcome of
the action before it was achieved. This finding suggests that infants’ predictive eye movements can be
elicited by a nonhuman self-propelled agent that provides varying and changing movements. We also
found that, overall, predictive gaze shifts occurred significantly earlier (i.e., infants were faster in
anticipating the outcome) in the efficient action condition than in the nonefficient action condition.
This finding implies that efficiency does have an influence on the anticipation of the outcome of an
ongoing action.
Our findings on the looking time analyses for the Jump and Obstacle AOIs exclude the possibility
that the difference in the timing of predictive looks between the two conditions was due to perceptual
differences between the two conditions, namely that the obstacle was only present in the efficient ac-
tion condition. Thus, the obstacle in the efficient action condition did not function as a ‘‘jumping
board’’ to quickly attract infants’ attention to the red circle. Furthermore, because the jumping action
did not occupy infants’ attention more in the nonefficient action condition than in the efficient action
condition, it cannot be argued that it was more interesting in the nonefficient action condition and,
therefore, kept infants from looking ahead.
It would seem that the finding that both conditions elicited predictive gaze does not support the
strong claim of the teleological stance theory about the critical role of the efficiency of an ongoing ac-
tion in anticipating its outcome. However, before we jump to this conclusion, two issues that may
have helped to elicit predictive gaze shifts need to be considered. First, because the blue circle’s jump
was followed by a straight-line approach of the red circle, it is possible that gaze shifts occurring dur-
ing this final approach simply reflected automatic extrapolation of the straight-line movement rather
than true goal anticipation (e.g., von Hofsten, Vishton, Spelke, Feng, & Rosander, 1998). We found that
in the nonefficient action condition, more predictive looks occurred during the period when the blue
circle was approaching the red circle along a straight line than during the period when the blue circle
was jumping. Therefore, the automatic extrapolation of the straight-line movement may have been
largely responsible for the predictive looks in the nonefficient action condition.
The second issue concerns the role of the red circle in eliciting gaze shifts. We suggest that the sal-
iency of the red circle may also have played a role in stimulating infants to look at the Goal AOI in both
conditions. The presence of the red circle is also related to a theoretical question about the necessity of
the presence of a well-defined visible goal object for goal anticipation. There is some indication that
the type of goal does influence anticipatory gaze shifts. Gredebäck and colleagues (2009) showed that
infants produced more anticipatory looks when objects were transferred into containers than when
objects were simply displaced to unmarked locations. Eshuis and colleagues (2009) demonstrated that
other outcome highlighting aspects, such as sound effects, can also influence the presence of predic-
tive looks in adults.
To address these issues, we conducted a second experiment with 13-month-olds in which the ani-
mation was changed in two respects, namely that the red circle was not present and we omitted the
final straight-line approach. After the blue circle jumped, it landed and disappeared behind a black
‘‘wall’’ that had the same color as the ground and, thus, did not seem to be distinct from it (see
Fig. 3). These modifications exclude the possibility of automatic straight-line extrapolation of the
movement, and they reduce the saliency of the goal object/area considerably.
S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427 421
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Experiment 2
Methods
Participants
A total of 36 13-month-old infants (mean age = 386.1 days, SD = 14.2, range = 368–411, 19 girls and
17 boys) participated in the experiment. An additional 12 infants also participated but were excluded
due to lack of reliable gaze data. Infants were randomly assigned to either the efficient action condition
or the nonefficient action condition. They were recruited through direct mail to their families and re-
ceived a gift after the experiment. Parents could opt to have their travel costs reimbursed.
Stimuli
The stimuli were similar to those in the previous experiment. However, there were two main dif-
ferences. One difference was that instead of a red circle, a black rectangular figure that looked like an
elevated ground was present on the left side of the screen. The second difference was that the small
blue circle did not roll to the left side of the screen but rather disappeared behind the black figure after
it had descended from its jump (see Fig. 3). The durations of the scenes were as follows: Introduction,
300 ms; Beginning, 3400 ms; Jumping, 1640 ms; and Arriving (behind the black figure), 1260 ms. The
total duration of one animation was 6600 ms. The order of the six animations and the difference be-
tween the efficient and nonefficient action conditions were identical to those in Experiment 1.
Procedure and apparatus
These were the same as those in Experiment 1.
Data analyses
The same criteria were used for the inclusion of participants and trials, and the same measures
were calculated from the raw data, as in Experiment 1.
NON-EFFICIENT ACTION
EFFICIENT ACTION
Goal
Goal
Jump
Start
Jump
Start
Obstacle
Obstacle
Fig. 3. Illustration of the animation with the areas of interest analyzed in Experiment 2.
422 S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427
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Results
There was no difference between the two conditions in the number of accepted trials, t(34) = 1.36,
p= .18, the mean total looking times, t(34) = 1,15, p= .25, or the number of overall fixations,
t(34) = 0.12, p= .90.
Gaze timing
Using one-sample ttests, the average time difference was tested against 0 for each condition. We
found that the average time difference was significantly above 0 in the efficient action condition,
t(17) = 2.83, p= .011, but not in the nonefficient action condition, t(17) = 0.55, p= .580 (see Fig. 4).
An independent-sample ttest showed no significant difference between the two conditions,
t(34) = 1.06, p= .29. A repeated-measures ANOVA with condition as a between-participants factor
and block as a within-participant variable was also carried out with only those infants who had valid
data in both blocks (16 infants in the nonefficient action condition and 18 infants in the efficient action
condition). The analysis revealed no significant effect of condition, F(1, 32) = 0.76, p= .38, or interac-
tion between block and condition, F(1,32) = 0.47, p= .49. In addition, paired-sample ttests revealed
that in the nonefficient action condition, there was a significantly higher percentage of trials with
reactive looks (M= 66.39%) than with predictive looks (M= 33.61%), t(18) = 2.39, p= .028), whereas
there was no difference between the two types of looks in the efficient action condition, t(18) = 0.92,
p= .36. During the Beginning scene, no difference was found between the two conditions in the num-
ber of fixations in the Goal AOI, t(34) = 1.44, p= . 15, because there was only 1 infant who fixated in
the Goal AOI in the nonefficient action condition and 4 infants who did so, each only once, in the effi-
cient action condition.
Looking time
Independent-sample ttests showed no difference between the two conditions in the average look-
ing time ratios for the Goal AOI, t(34) = 0.63, p= .52, and the Jump AOI, t(34) = 0.97, p= .33, relative
to the total looking time, or in the average looking time for the Jump AOI during the Jumping scene,
t(34) = 0.20, p= .83. An independent-sample ttest showed that infants tended to look longer at the
Obstacle AOI in the efficient action condition than in the nonefficient action condition, t(34) = 1.83,
p= .076. Furthermore, there was no difference in the number of times infants looked at the Goal AOI
right after they looked at the Obstacle AOI between the two conditions (8 infants in the efficient action
condition and 6 infants in the nonefficient action condition, each only once). When possible, the gaze
timing and looking time analyses were also carried out using the age (in days) of the infants as a covar-
iate. All of the effects remained the same, suggesting that age had no effect on the fixations.
Fig. 4. Mean gaze arrival in the Goal AOI relative to the arrival of the blue circle in Experiment 2. Positive values imply that the
gaze arrived before the circle. (For interpretation of the references to color in this figure legend, the reader is referred to the web
version of this article.)
S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427 423
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Discussion of Experiment 2
In Experiment 2 we found that, overall, 13-month-olds showed predictive looks (i.e., they shifted
their gaze to the outcome of the action before it was achieved) only in the efficient action condition.
In contrast, in the nonefficient action condition, infants showed reactive looks (i.e., they followed the
movement). This finding suggests that efficiency of the action was essential for goal anticipation in
this experiment.
Compared with the first experiment, Experiment 2 was modified in two important respects,
namely that the final straight-line approach was omitted and the salient red circle, which acted as
the goal object in Experiment 1, was replaced with a less distinct black figure behind which the blue
circle disappeared. Our finding that infants no longer showed predictive gaze shifts in the nonefficient
action condition in Experiment 2, thus, may have been caused by either of these two changes or by
their combination. Future research should aim to disentangle their exact roles in the lack of goal antic-
ipation. There is some evidence based on looking time measures (Csibra et al., 1999) that if only a par-
abolic path is taken to make contact with a salient goal object (and thus there is no straight-line
approach), then infants do not interpret this action as goal-directed unless the action can be consid-
ered as efficient given the situational constraints (i.e., an obstacle is present).
The efficient action condition elicited predictive gaze shifts in both Experiments 1 and 2, although
the predictive looks occurred considerably later in Experiment 2. This would suggest that the modifi-
cations affected the timing of predictive looks in the efficient action condition, but we need to be care-
ful when directly comparing the two experiments in terms of timing because the time window during
which infants could produce the anticipatory gaze shifts was shorter in Experiment 2 (given that it did
not contain the final approach). In any case, we can conclude from Experiment 2 that the presence of a
salient goal object is not necessary to elicit predictive gaze shifts as long as the ongoing action pro-
vides evidence for efficient adjustments to the given situation.
The presence of a salient, well-defined, and distinct object in the environment may facilitate
hypothesis formation about the potential outcome of an ongoing action, and its attractiveness may
help to anchor eye movements. Therefore, it would be interesting to test whether a completely un-
marked spatial position (which would be even less well-defined than our ‘‘wall’’ in Experiment 2)
could serve as a potential outcome that infants could anticipate if the efficiency of the ongoing action
could, in principle, justify it. Gredebäck and colleagues’ (2009) study showed that no predictive looks
were elicited when objects were simply displaced to another spatial location. However, in their study,
the displacement action did not provide movement cues for efficient adjustments. Empty spaces are
generally considered as difficult to represent or expect as a referent by infants (Butterworth & Jarrett,
1991; Churcher & Scaife, 1982; Csibra & Volein, 2008).
A final point to make regarding the comparison of the two experiments is that neither of them re-
vealed a ‘‘learning effect’’; that is, infants did not show earlier gaze shifts (faster anticipation) to the
Goal AOI in the later trials (Block 2) than in the earlier trials (Block 1). This is somewhat surprising
in that one would have expected that after several exposures to the goal attainment, infants could
have remembered what the outcome was and that this would be reflected in emerging or faster pre-
dictive looks to the goal area in subsequent trials. It is, however, not an unusual finding given that
other studies typically have not found a change across the trials in the timing of infants’ or adults’
anticipatory eye movements (e.g., Falck-Ytter et al., 2006; Gredebäck et al., 2009), although there
are exceptions (see Gredebäck & Melinder, 2010). Note, however, that due to missing trials, the
across-block comparison should be interpreted with caution in our study. We speculate that infants
may have considered each trial as a somewhat new situation in our experiments due to the slight dif-
ferences (changing sizes of the jump and the obstacle) between the animations and that this may have
prevented them from relying on the previously seen goal in their anticipation.
Conclusions
The aim of the current study was to investigate the role of the efficiency of nonhuman actions in
eliciting predictive gaze shifts toward the likely outcome of the action in 13-month-old infants. The
424 S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427
Author's personal copy
findings of the two experiments together suggest that the efficiency of the action not only influences
the timing of predictive looks but also may be essential for their presence.
Next, we return to the three hypotheses that we put forward in the Introduction. First, because we
found that predictive gaze shifts were produced in the case of novel actions of abstract geometric fig-
ures, we can reject the hypothesis that only human actions can elicit goal anticipation. Thus, the exclu-
sivity of a direct matching mechanism for goal anticipation does not hold. Second, our finding that the
nonefficient action condition did not elicit predictive gaze shifts in Experiment 2 does not support the
hypothesis that agent-defining self-propelled and varied movements are sufficient for predicting the
outcome of a nonhuman action. We caution, however, that Experiment 2 could not specify the role of
the lack of goal saliency in the absence of predictive looks in the nonefficient action condition. There-
fore, further research that clarifies whether the presence of a salient goal object can elicit predictive
looks during the observation of a self-propelled, varied, but nonefficient action is necessary to secure
this conclusion. Third, the finding that efficiency of the action affected the timing of predictive looks in
Experiment 1 and that it was necessary for the presence of predictive looks in Experiment 2 supports
the hypothesis that the application of the teleological schema is of crucial importance for the inference
of the outcome of novel ongoing actions. Experiment 2 showed that infants are able to rely on the effi-
ciency of the action to anticipate the goal even when the goal object is not salient. This ability is cer-
tainly very beneficial because potential goal states or goal objects often do not have salient features in
a complex environment.
Our findings are consistent with the results of previous studies that used looking time measures to
test the ability of infants to infer the outcome of an incomplete nonhuman action based on the effi-
ciency of the action (Csibra et al., 2003; Southgate & Csibra, 2009; Wagner & Carey, 2005). Moreover,
because we used predictive eye movements as our measure, our results are not subject to the alter-
native interpretation of reflecting retrospective evaluation of the witnessed outcome because antici-
patory eye movements are elicited before the outcome is achieved.
Compared with other studies using predictive eye movements as a measure, our study nicely com-
plements Gredebäck and Melinder’s (2010) study that demonstrated the influence of the efficiency of
human action on goal anticipation. Unlike their study, ours avoids confounding efficiency and famil-
iarity because the actions of geometric figures were presumably novel for the infants in our study.
At first glance, our results from Experiment 2 seem to be in conflict with the finding of Paulus and
colleagues’ (2011) study in which infants’ predictive looks were not found to be affected by the
assumption about the efficiency of actions. One reason for the contrasting results could be the younger
age of the infants (9 months) in Paulus and colleagues’ study. Another reason might be the difference
in the type of inferences that the infants needed to make. We think that the two experiments are sim-
ilar in the sense that the representation of the goal was demanding in both, albeit in different ways. In
our Experiment 2, the agent disappeared (the circle went behind the barrier) while the nonsalient goal
object remained in place. In Paulus and colleagues’ study, both the agent and the salient goal object
disappeared, so the goal state was not seen as being achieved. However, the major difference between
the two experiments is that in ours infants were only required to anticipate the nonsalient goal. In
Paulus and colleagues’ study, on the other hand, infants needed to cope with two inferences; they
needed to infer and keep in mind the unseen goal and they needed to anticipate the means. The fact
that this double requirement was not present in our experiment may explain why infants in our
experiment could take the efficiency of the action into account. Further research could clarify the rel-
ative contributions of age, type of inference, and goal saliency to infants’ ability to rely on the principle
of efficient action for predictive inferences measured by anticipatory eye movements. For example, it
could be tested whether infants are able to apply the efficiency principle in their anticipation of a no-
vel means in case of a salient goal or whether 9-month-olds can anticipate a nonsalient goal based on
the efficiency of an ongoing action.
Finally, we discuss an issue that is related to the type of fixations one can collect from the goal area
and the criterion that we used to consider a fixation to the goal area as anticipatory. Recall that we
included only those fixations in our analysis that occurred after the start of the jumping of the circle.
This criterion was used to ensure that the efficiency of the action can be evaluated in both the pres-
ence and absence of the obstacle. However, fixations to the Goal AOI were also produced before the
jumping started, namely during the Beginning scene when the circle was moving back and forth.
S. Biro / Journal of Experimental Child Psychology 116 (2013) 415–427 425
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These early fixations to the Goal AOI may have been part of generic explorative behavior. On the other
hand, it is possible that some of these early fixations were predictive (at least some of those that oc-
curred after the first trial) because infants could, in principle, have anticipated the goal on the basis of
having witnessed the goal state being achieved in previous trials. When we looked at fixations to the
Goal AOI before the jumping started in Experiment 1, we found that more fixations occurred in the
efficient action condition than in the nonefficient action condition and by many more infants. Hence,
even if some of these early fixations could be considered as anticipatory looks, it is likely that these
occurred more often in the efficient action condition. We could speculate that even repetition-based
anticipations may have been influenced by efficiency, which would further strengthen our results.
However, in Experiment 2 only a few fixations occurred in the Goal AOI before jumping started. This
suggests that in Experiment 1 the saliency of the goal played an important role in eliciting these early
fixations regardless of whether they were anticipatory or exploratory. Overall, we believe that the cri-
terion we used was certainly ‘‘safe’’ in the sense that the fixation to the Goal AOI reflected true antic-
ipation of the outcome of the action.
In summary, our findings support the importance of teleological inferences for the anticipation of
the goals of ongoing actions during infancy. We do not claim that teleological predictive inference is
the only mechanism through which infants or adults can anticipate the likely outcome of an ongoing
action. Familiarity with an action through prior observational or own action experience can allow one
to anticipate its likely outcome in the absence of direct evidence for efficient adjustments of the action
(Cannon & Woodward, 2012; Daum, Prinz, & Aschersleben, 2008; Falck-Ytter et al., 2006; Southgate &
Csibra, 2009). Teleological inferences can, however, be particularly useful in case of novel actions and
in situations where multiple potential outcomes are available, and evaluation of the efficiency of the
action can help to disambiguate the likely outcome (Biro et al., 2011; Verschoor & Biro, 2012).
Acknowledgment
I thank the two anonymous reviewers for their valuable comments on the first version of the
manuscript.
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... Additionally, we studied whether the production of a salient action effect, as a potential agency cue (e.g., Bíró and Leslie, 2007), influences infants' predictive gaze behavior. Recent research suggests that infants are able to predict the goal of actions by non-human agents, as long as these agents exhibit certain behavioral agency cues, such as self-propelled movement, equifinality of goal achievement, or the ability to produce salient action effects (e.g., Bíró, 2013;Adam and Elsner, 2018). For example, Adam and Elsner (2018) presented 11-montholds with videos of a mechanical claw approaching a toy on a linear path. ...
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During the observation of goal-directed actions, infants usually predict the goal when the action and the agent are familiar, but they do not as easily predict the goal when the action or the agent are unfamiliar. Recent theoretical accounts suggest that predictive gaze behavior relies on a complex interplay between bottom-up- (e.g., agency cues) and top- down information (e.g., prior experience with the action), depending on an observer’ prior knowledge about the unfolding action event. Based on these accounts, we hypothesized that during the observation of grasping actions performed by a mechanical claw, younger infants would need agency cues to show predictive gaze behavior, whereas older infants would be able to show predictive gaze behavior regardless of agency cues. Therefore, we presented 7-, 11-, and 18-month-old infants with videos of a mechanical claw that repeatedly approached and grasped a goal object and then either did or did not produce a salient action effect. The 7-month-olds were not predictive regardless of the salient action effect, the 11-month-olds were only predictive when the salient action effect was presented, and the 18-month-olds were predictive regardless of the salient action effect. These results therefore support the idea of a complex interplay between bottom-up and top-down information as a crucial factor for the production of predictive gaze behavior during the observation of goal-directed actions performed by mechanical agents.
... It should be noted that the movement of the blocks 24 followed the rules of biological movement, as it depended on the action of the hidden agent. Southgate (2013) suggested that for unfamiliar agents like apparently self-propelled objects, further 1 cues to goal-directedness may be required (as in Biro, 2013). Therefore, it seems that to evoke 2 motor activity in the observer, the presence of biological movement is not sufficient but the ...
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Others' action observation activates in the observer a coordinated hand-eye motor program, covert for the hand (i.e. motor resonance), and overt for the eye (i.e. proactive gaze), similar to that of the observed agent. The biological motion hypothesis of action anticipation claims that proactive gaze occurs only in the presence of biological motion, and that kinematic information is sufficient to determine the anticipation process. The results of the present study did not support the biological motion hypothesis of action anticipation. Specifically, proactive gaze was present during observation of both a biological accelerated-decelerated motion and a non-biological constant velocity motion (Experiment 1), in the presence of a barrier able to restrict differences between the two kinematics to the motion profile of individual markers prior to contact (Experiment 2), but only if an object was present at the end point of the movement trajectory (Experiment 3). Furthermore, proactive gaze was found independently of the presence of end effects temporally congruent with the instant in which the movement stopped (Experiments 4, and 5). We propose that the involvement of the observer's motor system is not restricted to when the agent moves with natural kinematics, and it is mandatory whenever the presence of an agent or a goal is evident, regardless of physical appearance, natural kinematics, and the possibility to identify the action behind the stimulus.
... Apparently, observed action effects are particularly helpful for future action-goal prediction (Adam & Elsner, 2018;Elsner, 2007;Eshuis et al., 2009;Uithol & Paulus, 2014). Because infants primarily gain experience with agents that display agency cues (i.e., own or others' body limbs ;B ır o, 2013;B ır o & Leslie, 2007), this perceivable information is also stored in action-event schemata, until finally, perceiving only the initial state and the agent's features allows for goal prediction (Fig. 2B). Further, when an unfamiliar agent or action displays visible agency cues, a corresponding familiar action-event schema with similar initial features may become activated (i.e., human reaching), enabling a predictive gaze-shift via top-down influences after having tracked the complete action event during the first trials. ...
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Looking times and gaze behavior indicate that infants can predict the goal state of an observed simple action event (e.g., object-directed grasping) already in the first year of life. The present paper mainly focuses on infants' predictive gaze-shifts toward the goal of an ongoing action. For this, infants need to generate a forward model of the to-be-obtained goal state and to disengage their gaze from the moving agent at a time when information about the action event is still incomplete. By about 6 months of age, infants show goal-predictive gaze-shifts, but mainly for familiar actions that they can perform themselves (e.g., grasping) and for familiar agents (e.g., a human hand). Therefore, some theoretical models have highlighted close relations between infants' ability for action-goal prediction and their motor development and/or emerging action experience. Recent research indicates that infants can also predict action goals of familiar simple actions performed by non-human agents (e.g., object-directed grasping by a mechanical claw) when these agents display agency cues, such as self-propelled movement, equifinality of goal approach, or production of a salient action effect. This paper provides a review on relevant findings and theoretical models, and proposes that the impacts of action experience and of agency cues can be explained from an action-event perspective. In particular, infants' goal-predictive gaze-shifts are seen as resulting from an interplay between bottom-up processing of perceptual information and top-down influences exerted by event schemata that store information about previously executed or observed actions.
... This entails, for example, the agent's behavior because the agent might act in ways or manipulate the goal object in ways that help the observer to reason about the action goal and to also store this new knowledge as top-down information for future observations. This line of reasoning fits well to prior research showing that infants tend to anticipate goals more successfully when they have prior experience with the agent or the action, but are also able to predict the goal of unfamiliar agents or actions when bottom-up information is provided during action observation (e.g., Adam & Elsner, 2018;Adam et al., 2017;Biro, 2013). ...
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From about 7 months of age onward, infants start to reliably fixate the goal of an observed action, such as a grasp, before the action is complete. The available research has identified a variety of factors that influence such goal-anticipatory gaze shifts, including the experience with the shown action events and familiarity with the observed agents. However, the underlying cognitive processes are still heavily debated. We propose that our minds (i) tend to structure sensorimotor dynamics into probabilistic, generative event-predictive, and event boundary predictive models, and, meanwhile, (ii) choose actions with the objective to minimize predicted uncertainty. We implement this proposition by means of event-predictive learning and active inference. The implemented learning mechanism induces an inductive, event-predictive bias, thus developing schematic encodings of experienced events and event boundaries. The implemented active inference principle chooses actions by aiming at minimizing expected future uncertainty. We train our system on multiple object-manipulation events. As a result, the generation of goal-anticipatory gaze shifts emerges while learning about object manipulations: the model starts fixating the inferred goal already at the start of an observed event after having sampled some experience with possible events and when a familiar agent (i.e., a hand) is involved. Meanwhile, the model keeps reactively tracking an unfamiliar agent (i.e., a mechanical claw) that is performing the same movement. We qualitatively compare these modeling results to behavioral data of infants and conclude that event-predictive learning combined with active inference may be critical for eliciting goal-anticipatory gaze behavior in infants.
... Behavioral and electrophysiological evidence suggests that we not only recognize completed actions as goaldirected, but also infer the goals and outcomes of certain actions of others even before they are achieved (Southgate et al., 2010). Anticipatory looking (AL) measures, in particular, have shown that infants and adults spontaneously gaze toward the expected outcome of another agent's unfolding behavior and thus reveal active, goal-based action prediction Biro, 2013;Cannon & Woodward, 2012;Falck-Ytter et al., 2006;Gredebäck et al., 2018;Kanakogi & Itakura, 2011;Kochukhova & Gredebäck, 2010; for review, see ; but see Ganglmayer et al., 2019). ...
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Do children and adults engage in spontaneous Theory of Mind (ToM)? Accumulating evidence from anticipatory looking (AL) studies suggests that they do. But a growing body of studies failed to replicate these original findings. This paper presents the first step of a large-scale multi-lab collaboration dedicated to testing the robustness of spontaneous ToM measures. It examines whether 18-27-month-olds and adults’ anticipatory looks distinguish between knowledgeable and ignorant agents. In a pre-registered study with toddlers [anticipated N = 440, 50% female] and adults [anticipated N = 360, 50% female] from diverse ethnic backgrounds, we found that [DESCRIBE RESULT AND EFFECT SIZE FOR MAIN CONFIRMATORY ANALYSIS]. This provides [SUPPORT/SOME SUPPORT/NO SUPPORT] for spontaneous, epistemic state-based action anticipation in an AL paradigm.
... In the absence of competitor target objects, several studies have shown that infants fail to attribute goals to the observed actions, due to the lack of evidence for the agent's preference between the alternative objects (e.g., Luo & Baillargeon, 2005). However, other studies (Hernik & Southgate, 2012) demonstrated that an absence of an alternative target object does not necessarily disrupt goal attribution, so long as the actions that the infants observe follow the principles of rationality or efficiency (Biro, 2013;Csibra, 2008;Gergely et al., 1995), such as agents approaching a target by taking a path that is no longer than necessary and is justified by the situational constraints (Hernik & Southgate, 2012). Thus, the second modification in our stimuli compared to the standard Woodward task was such that both agents approached the targets by taking unnecessary detours, thereby making their actions individually inefficient. ...
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Interpreting others’ actions as goal-directed, even when the actions are unfamiliar, is indispensable for social learning, and can be particularly important for infants, whose own action repertoire is limited. Indeed, young infants have been shown to attribute goals to unfamiliar actions as early as 3 months of age, but this ability appears restricted to actions performed by individuals. In contrast, attributing shared goals to actions performed by multiple individuals seems to emerge only in the second year of life. Considering the restrictions that this would impose on infants’ understanding and learning from interactions in their environment, we re-examine this ability by introducing 9-month-old infants to simple joint actions, in which two agents coordinate their actions towards the same goal. To establish whether infants formed an expectation about future actions of these agents, infants’ cortical activity was measured using functional near-infrared spectroscopy (fNIRS). The haemodynamic response, recorded in (p)STS, indicated that infants attributed goals to simultaneous and coordinated joint actions of two individuals. Thus, even prior to actively engaging in collaborative activities themselves, infants can attribute shared goals to observed joint actions, enabling them to learn from, and about, the complementary roles of social interactions, a central characteristic of human culture.
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Learning about actions requires children to identify the boundaries of an action and its units. Whereas some action units are easily identified, parents can support children's action learning by adjusting the presentation and using social signals. However, currently little is understood regarding how children use these signals to learn actions. In the current study we investigate the possibility that communicative signals are a particularly suitable cue for segmenting events. We investigated this hypothesis by presenting 18-month-old children (N = 60) with short action sequences consisting of toy animals either hopping or sliding across a board into a house, but interrupting this two-step sequence either (a) using an ostensive signal as a segmentation cue, (b) using a non-ostensive segmentation cue, and (c) without additional segmentation information between the actions. Marking the boundary using communicative signals increased children's imitation of the less salient sliding action. Imitation of the hopping action remained unaffected. Crucially, marking the boundary of both actions using a non-communicative control condition did not increase imitation of either action. Communicative signals might be particularly suitable in segmenting non-salient actions that would otherwise be perceived as part of another action or as non-intentional. These results provide evidence of the importance of ostensive signals at event boundaries in scaffolding children's learning.
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Recent theories stress the role of situational information in understanding others’ behaviour. For example, the predictive coding framework assumes that people take contextual information into account when anticipating other’s actions. Likewise, the teleological stance theory assumes an early developing ability to consider situational constraints in action prediction. The current study investigates, over a wide age range, whether humans flexibly integrate situational constraints in their action anticipations. By means of an eye-tracking experiment, 2-year-olds, 5-year-olds, younger and older adults (together N = 181) observed an agent repeatedly taking one of two paths to reach a goal. Then, this path became blocked, and for test trials only the other path was passable. Results demonstrated that in test trials younger and older adults anticipated that the agent would take the continuous path, indicating that they took the situational constraints into account. In contrast, 2- and 5-year-olds anticipated that the agent would take the blocked path, indicating that they still relied on the agent’s previous observed behaviour and—contrary to claims by the teleological stance theory—did not take the situational constraints into account. The results highlight developmental changes in human’s ability to include situational constraints in their visual anticipations. Overall, the study contributes to theories on predictive coding and the development of action understanding.
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We propose that the crucial difference between human cognition and that of other species is the ability to participate with others in collaborative activities with shared goals and intentions: shared intentionality. Participation in such activities requires not only especially powerful forms of intention reading and cultural learning, but also a unique motivation to share psychological states with others and unique forms of cognitive representation for doing so. The result of participating in these activities is species-unique forms of cultural cognition and evolution, enabling everything from the creation and use of linguistic symbols to the construction of social norms and individual beliefs to the establishment of social institutions. In support of this proposal we argue and present evidence that great apes (and some children with autism) understand the basics of intentional action, but they still do not participate in activities involving joint intentions and attention (shared intentionality). Human children's skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine: (1) the general ape line of understanding others as animate, goal-directed, and intentional agents; and (2) a species-unique motivation to share emotions, experience, and activities with other persons. The developmental outcome is children's ability to construct dialogic cognitive representations, which enable them to participate in earnest in the collectivity that is human cognition.
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Human infants readily interpret others' actions as goal-directed and their understanding of previous goals shapes their expectations about an agent's future goal-directed behavior in a changed situation. According to a recent proposal (Luo & Baillargeon, 2005), infants' goal-attributions are not sufficient to support such expectations if the situational change involves broadening the set of choice-options available to the agent, and the agent's preferences among this broadened set are not known. The present study falsifies this claim by showing that 9-month-olds expect the agent to continue acting towards the previous goal even if additional choice-options become available for which there is no preference-related evidence. We conclude that infants do not need to know about the agent's preferences in order to form expectations about its goal-directed actions. Implications for the role of action persistency and action selectivity are discussed.
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A series of experiments is reported which show that three successive mechanisms are involved in the first 18 months of life in ‘looking where someone else is looking’. The earliest ‘ecological’ mechanism enables the infant to detect the direction of the adult's visual gaze within the baby's visual field but the mother's signal alone does not allow the precise localization of the target. Joint attention to the same physical object also depends on the intrinsic, attention-capturing properties of the object in the environment. By about 12 months, we have evidence for presence of a new ‘geometric’ mechanism. The infant extrapolates from the orientation of the mother's head and eyes, the intersection of the mother's line of sight within a relatively precise zone of the infant's own visual space. A third ‘representational’ mechanism emerges between 12 and 18 months, with an extension of joint reference to places outside the infant's visual field. None of these mechanisms require the infant to have a theory that others have minds; rather the perceptual systems of different observers ‘meet’ in encountering the same objects and events in the world. Such a ‘realist’ basis for interpersonal knowledge may offer an alternative starting point for development of intrapersonal knowledge, rather than the view that mental events can only be known by construction of a theory.
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• As the title suggests, this book examines the psychology of interpersonal relations. In the context of this book, the term "interpersonal relations" denotes relations between a few, usually between two, people. How one person thinks and feels about another person, how he perceives him and what he does to him, what he expects him to do or think, how he reacts to the actions of the other--these are some of the phenomena that will be treated. Our concern will be with "surface" matters, the events that occur in everyday life on a conscious level, rather than with the unconscious processes studied by psychoanalysis in "depth" psychology. These intuitively understood and "obvious" human relations can, as we shall see, be just as challenging and psychologically significant as the deeper and stranger phenomena. The discussion will center on the person as the basic unit to be investigated. That is to say, the two-person group and its properties as a superindividual unit will not be the focus of attention. Of course, in dealing with the person as a member of a dyad, he cannot be described as a lone subject in an impersonal environment, but must be represented as standing in relation to and interacting with another person. The chapter topics included in this book include: Perceiving the Other Person; The Other Person as Perceiver; The Naive Analysis of Action; Desire and Pleasure; Environmental Effects; Sentiment; Ought and Value; Request and Command; Benefit and Harm; and Reaction to the Lot of the Other Person. (PsycINFO Database Record (c) 2012 APA, all rights reserved) • As the title suggests, this book examines the psychology of interpersonal relations. In the context of this book, the term "interpersonal relations" denotes relations between a few, usually between two, people. How one person thinks and feels about another person, how he perceives him and what he does to him, what he expects him to do or think, how he reacts to the actions of the other--these are some of the phenomena that will be treated. Our concern will be with "surface" matters, the events that occur in everyday life on a conscious level, rather than with the unconscious processes studied by psychoanalysis in "depth" psychology. These intuitively understood and "obvious" human relations can, as we shall see, be just as challenging and psychologically significant as the deeper and stranger phenomena. The discussion will center on the person as the basic unit to be investigated. That is to say, the two-person group and its properties as a superindividual unit will not be the focus of attention. Of course, in dealing with the person as a member of a dyad, he cannot be described as a lone subject in an impersonal environment, but must be represented as standing in relation to and interacting with another person. The chapter topics included in this book include: Perceiving the Other Person; The Other Person as Perceiver; The Naive Analysis of Action; Desire and Pleasure; Environmental Effects; Sentiment; Ought and Value; Request and Command; Benefit and Harm; and Reaction to the Lot of the Other Person. (PsycINFO Database Record (c) 2012 APA, all rights reserved)