Neonatal imitation in chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>) tested with two paradigms

Primate species differ in their imitative performance, perhaps reflecting differences in imitative capacity. The developmentally earliest form of imitation in humans, neonatal imitation, occurs in early interactions with social partners, and may be a more accurate index of innate capacity than imitation of actions on objects, which requires more cognitive ability. This study assessed imitative capacity in five neonatal chimpanzees, within a narrow age range (7–15 days of age), by testing responses to facial and vocal actions with two different test paradigms (structured and communicative). Imitation of mouth opening was found in both paradigms. In the communicative paradigm, significant agreement was found between infant actions and demonstrations. Additionally, chimpanzees matched the sequence of three actions of the TC model, but only on the second demonstration. Newborn chimpanzees matched more modeled actions in the communicative test than in the structured paradigm. These performances of chimpanzees, at birth, are in agreement with the literature, supporting a conclusion that imitative capacity is not unique to the human species. Developmental histories must be more fully considered in the cross-species study of imitation, as there is a greater degree of innate imitative capacity than previously known. Socialization practices interact with innate and developing competencies to determine the outcome of imitation tests later in life.     

Deferred imitation in 18-month-olds from two cultural contexts: The case of Cameroonian Nso farmer and German-middle class infants

Imitative learning has been described in naturalistic studies for different cultures, but lab-based research studying imitative learning across different cultural contexts is almost missing. Therefore, imitative learning was assessed with 18-month-old German middle-class and Cameroonian Nso farmer infants – representing two highly different eco-cultural contexts associated with different cultural models, the psychological autonomy and the hierarchical relatedness – by using the deferred imitation paradigm. Study 1 revealed that the infants from both cultural contexts performed a higher number of target actions in the deferred imitation than in the baseline phase. Moreover, it was found that German middle-class infants showed a higher mean imitation rate as they performed more target actions in the deferred imitation phase compared with Cameroonian Nso farmer infants. It was speculated that the opportunity to manipulate the test objects directly after the demonstration of the target actions could enhance the mean deferred imitation rate of the Cameroonian Nso farmer infants which was confirmed in Study 2. Possible explanations for the differences in the amount of imitated target actions of German middle-class and Cameroonian Nso farmer infants are discussed considering the object-related, dyadic setting of the imitation paradigm with respect to the different learning contexts underlying the different cultural models of learning.     

Do as I … Did! Long-term memory of imitative actions in dogs (<Emphasis Type="Italic">Canis familiaris</Emphasis>)

This study demonstrates long-term declarative memory of imitative actions in a non-human animal species. We tested 12 pet dogs for their ability to imitate human actions after retention intervals ranging from 1 to 24 h. For comparison, another 12 dogs were tested for the same actions without delay between demonstration and recall. Our test consisted of a modified version of the Do as I Do paradigm, combined with the two-action procedure to control for non-imitative processes. Imitative performance of dogs remained consistently high independent of increasing retention intervals, supporting the idea that dogs are able to retain mental representations of human actions for an extended period of time. The ability to imitate after such delays supports the use of long-term declarative memory.     

The development of imitation by reinforcing behavioral similarity to a model

This research demonstrated some of the conditions under which retarded children can be taught to imitate the actions of adults. Before the experiment, the subjects were without spontaneous imitative behavior, either vocal or motor. Each subject was taught, with food as reinforcement, a series of responses identical to responses demonstrated by an experimenter; i.e., each response was reinforced only if it was identical to a prior demonstration by an experimenter. Initially, intensive shaping was required to establish matching responses by the subjects. In the course of acquiring a variety of such responses, the subjects' probability of immediate imitation of each new demonstration, before direct training, greatly increased. Later in the study, certain new imitations, even though perfect, were never reinforced; yet as long as some imitative responses were reinforced, all remained at high strength. This imitativeness was then used to establish initial verbal repertoires in two subjects.     

Beyond the information given: Infants’ transfer of actions learned through imitation

Five experiments were conducted to investigate infants’ ability to transfer actions learned via imitation to new objects and to examine what components of the original context are critical to such transfer. Infants of 15 months observed an experimenter perform an action with one or two toys and then were offered a novel toy that was not demonstrated for them. In all experiments, infants performed target actions with the novel toy more frequently than infants who were offered the same toy but had seen no prior demonstrations. Infants exhibited transfer even when the specific part to be manipulated looked different across the toys, even when they had not performed the actions with the demonstration toys themselves, even when the actions produced no effects on the demonstrations, and even when the actions were demonstrated with only a single exemplar toy. Transfer was especially robust when infants not only observed but also practiced the target actions on the demonstration trials. Learning action affordances (“means”) seems to be a central aspect of human imitation, and the propensity to apply these learned action affordances in new object contexts may be an important basis for technological innovation and invention.     

Action observation produces motor resonance in Parkinson's disease

Observation of movement activates the observer's own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task‐irrelevant) action. The impact of movement disorders such as Parkinson's disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus‐response compatibility effects. We examined visuomotor priming in 23 participants with mild‐to‐moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus‐response compatibility. Participants made a key press after observing a task‐irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus‐response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.     

Multiple Framing: Verbal,Facial, and Vocal Cues in Risky Choice

Verbal framing effects have been widely studied, but little is known about how people react to multiple framing cues in risk communication, where verbal messages are often accompanied by facial and vocal cues. We examined joint and differential effects of verbal, facial, and vocal framing on risk preference in hypothetical monetary and life–death situations. In the multiple framing condition with the factorial design (2 verbal frames × 2 vocal tones × 4 basic facial expressions × 2 task domains), each scenario was presented auditorily with a written message on a photo of the messenger's face. Compared with verbal framing effects resulting in preference reversal, multiple frames made risky choice more consistent and shifted risk preference without reversal. Moreover, a positive tone of voice increased risk‐seeking preference in women. When the valence of facial and vocal cues was incongruent with verbal frame, verbal framing effects were significant. In contrast, when the affect cues were congruent with verbal frame, framing effects disappeared. These results suggest that verbal framing is given higher priority when other affect cues are incongruent. Further analysis revealed that participants were more risk‐averse when positive affect cues (positive tone or facial expressions) were congruently paired with a positive verbal frame whereas participants were more risk‐seeking when positive affect cues were incongruent with the verbal frame. In contrast, for negative affect cues, congruency promoted risk‐seeking tendency whereas incongruency increased risk‐aversion. Overall, the results show that facial and vocal cues interact with verbal framing and significantly affect risk communication. Copyright © 2016 John Wiley & Sons, Ltd.     

Copying results and copying actions in the process of social learning: chimpanzees (Pan troglodytes) and human children (Homo sapiens)

There is currently much debate about the nature of social learning in chimpanzees. The main question is whether they can copy others' actions, as opposed to reproducing the environmental effects of these actions using their own preexisting behavioral strategies. In the current study, chimpanzees (Pan troglodytes) and human children (Homo sapiens) were shown different demonstrations of how to open a tube-in both cases by a conspecific. In different experimental conditions, demonstrations consisted of (1) action only (the actions necessary to open the tube without actually opening it); (2) end state only (the open tube, without showing any actions); (3) both of these components (in a full demonstration); or (4) neither of these components (in a baseline condition). In the first three conditions subjects saw one of two different ways that the tube could open (break in middle; caps off ends). Subjects' behavior in each condition was assessed for how often they opened the tube, how often they opened it in the same location as the demonstrator, and how often they copied the demonstrator's actions or style of opening the tube. Whereas chimpanzees reproduced mainly the environmental results of the demonstrations (emulation), human children often reproduced the demonstrator's actions (imitation). Because the procedure used was similar in many ways to the procedure that Meltzoff (Dev Psych 31:1, 1995) used to study the understanding of others' unfulfilled intentions, the implications of these findings with regard to chimpanzees' understanding of others' intentions are also discussed.     

Development of verbal control over bizarre gestures of retardates through imitative and nonimitative reinforcement procedures

Two retardates, manifesting hand gestures and minimal instructional control, were trained by imitative reinforcement procedures to imitate a response that was in contrast to gesturing. Next, with the contrast response continuing to be imitatively reinforced, gesturing was reduced by nonimitative reinforcement procedures; while providing facial and gesture cues, the adult said, "Do not do this". Imitative and nonimitative procedures were found to have the same effects on the contrast response as on the gesturing response, such that imitative procedures increased both responses, whereas nonimitative procedures decreased both. Nonperformance of gesturing was further maintained when (1) explicit verbal directions for nongesturing were superimposed upon the demonstrational-facial-verbal cues as these collective stimuli were faded out and (2) food reinforcers for nongesturing were gradually removed while social consequences continued to be administered.     

Specificity in practice benefits learning in novice models and variability in demonstration benefits observational practice

Considerable research has shown that both demonstration and verbal instruction can facilitate learning of a motor task in inexperienced individuals. In the current study, verbal instructions were used as a means to reduce the discovery learning process and control the amount of trial-to-trial variability in demonstrations. The task required models to learn to trace a pair of circles with a 90°-relative phase pattern between the arms. Verbal instructions directed one group of models toward a single strategy, and this group improved at a faster rate and performed better in a 24-h retention test compared to a group of models in a discovery learning context. The discovery models utilized multiple strategies throughout the practice. Each model was watched for 2 days by an observer, who was instructed that they would have to produce the 90°-relative phase pattern on day 3. Observers, who watched the discovery models, performed better than those who watched the single strategy models. The results support two primary conclusions. First, trial-to-trial variability associated with strategy selection processes in a model benefits an observer by facilitating perceptual discrimination processes that may play a key role in action generation. Second, verbal instructions that reduce discovery learning during physical practice benefit acquisition and retention performance when the task has multiple strategies wherein no one strategy guarantees the best performance outcome.     

Imitating step by step: a detailed analysis of 9- to 15-month-olds' reproduction of a three-step action sequence

To investigate what infants around their first birthday learn from observing an action sequence, 9- to 15-month-olds' imitative behavior was compared in three conditions: a demonstration group watched three target action steps and a final outcome, a control group observed only the third step and final outcome, and a baseline group received no demonstration. After a short delay, the demonstration infants of all ages produced more target actions than the control and baseline infants. Moreover, the latency to the first step was shortest in the demonstration condition. Data about the performance of the single steps in each age sample revealed which target actions were novel to the infants, and which steps were learned by observation. Infants in the control condition did not generate the unseen target action steps. It is concluded that infants' memory capacity and their ability to encode action-effect relations contribute to their imitation of an action sequence.     

Eighteen-month-olds integrate verbal cues into their action processing: Evidence from ERPs and mu power

Behavioral research has shown that infants use both behavioral cues and verbal cues when processing the goals of others’ actions. For instance, 18-month-olds selectively imitate an observed goal-directed action depending on its (in)congruence with a model’s previous verbal announcement of a desired action goal. This EEG-study analyzed the electrophysiological underpinnings of these behavioral findings on the two functional levels of conceptual action processing and motor activation. Mid-latency mean negative ERP amplitude and mu-frequency band power were analyzed while 18-month-olds (N = 38) watched videos of an adult who performed one out of two potential actions on a novel object. In a within-subjects design, the action demonstration was preceded by either a congruent or an incongruent verbally announced action goal (e.g., “up” or “down” and upward movement). Overall, ERP negativity did not differ between conditions, but a closer inspection revealed that in two subgroups, about half of the infants showed a broadly distributed increased mid-latency ERP negativity (indicating enhanced conceptual action processing) for either the congruent or the incongruent stimuli, respectively. As expected, mu power at sensorimotor sites was reduced (indicating enhanced motor activation) for congruent relative to incongruent stimuli in the entire sample. Both EEG correlates were related to infants’ language skills. Hence, 18-month-olds integrate action-goal-related verbal cues into their processing of others’ actions, at the functional levels of both conceptual processing and motor activation. Further, cue integration when inferring others’ action goals is related to infants’ language proficiency.     

Working memory and mental arithmetic: A case for dual central executive resources

The current study was designed to examine the possible existence of two limited-capacity pools of central executive resources: one each for verbal and visuospatial processing. Ninety-one college students (M age = 19.0, SD = 2.2) were administered a verbal working memory task that involved updating numbers in 2-, 3-, and 4-load conditions. The task was administered in both single task (no-interference condition) and dual-task (verbal interference and visuospatial interference conditions) formats. Findings indicated main effects for both memory load and type of interference, as well as, a load × interference interaction. Verbal interference led to a steeper increase in errors on the primary verbal working memory task; whereas, there was a smaller increase in errors across load in both the non-verbal and no-interference conditions. The effect of verbal interference and the lack of a spatial interference effect on a primary task that utilized verbal working memory resources, suggests that the processing of verbal and spatial stimuli in a dual-task paradigm requires separate central executive resources.     

Imitative play behavior of children: The importance of model distinctiveness and prior imitative training

The frequency of play behaviors of nursery school and second grade subjects (N = 116) who were imitative of one of two models depended upon the extent to which the two models were previously distinguished by the proportion of reinforcement each delivered, and whether reinforcement delivery was contingent upon imitative behavior. A model, high in distinctiveness and also involved in prior imitative training, engendered reliably more imitations than models high (or low) in distinctiveness but involved in nonimitative (or imitative) training.     

Framing Effects: Dynamics and Task Domains

The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life–death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life–death choice problems than facing the counterpart problems presented in the other two task domains. Subjects’ risk preference varied categorically along the group size dimension in the life–death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame–risk aversion and negative frame–risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. Abidirectional framing effectinvolves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, aunidirectional framing effectrefers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable models of human decision making.     

A New Look at Framing Effects: Distribution of Effect Sizes,Individual Differences,and Independence of Types of Effects

Levin, Schneider, and Gaeth (1998) identified three distinct types of framing effects in the literature: attribute framing effects, goal framing effects, risky choice framing effects. While most previous framing studies used between-subjects manipulations of frame, the present study used two sessions, spaced one week apart, to give each of 102 participants both framing conditions and all three types of framing. Using the difference between the score for the positive framing condition and the negative framing condition as the unit of analysis for each type of framing effect, the following were found: (1) reliable framing effects for attribute framing and risky choice framing, but not for goal framing; (2) distributions of individual framing effects showing that the aggregate-level effects were representative of individuals even though some individuals showed no framing effects; (3) no significant interdependencies between the three categories of framing effects; (4) individual differences in reaction to the task scenarios related to various of the “Big Five” personality traits as well as the Faith in Intuition scale. The use of within-subject designs to assess individual differences in decision-making phenomena such as framing effects and other biases and heuristics is recommended for future research.     

Imitation of causally opaque versus causally transparent tool use by 3- and 5-year-old children

We investigated whether the tendency to imitate or emulate is influenced by the availability of causal information, and the amount of information available in a display. Three and 5-year-old children were shown by either a live or video model how to obtain a reward from either a clear or an opaque puzzle box. Some of the actions in the sequence were causally relevant to retrieving the reward, whereas others were irrelevant. The clear box made the causally irrelevant actions visible, whereas the opaque box prevented them from being seen. Results indicated that both 3- and 5-year-old children imitated the irrelevant actions regardless of the availability of causal information following a live demonstration. In contrast, the 3-year-olds employed an emulative approach, omitting irrelevant actions, when the information available was degraded in a video demonstration. However, the 5-year-olds were unaffected by the degraded information and employed an imitative approach. We suggest that imitation develops to be such an adaptive human strategy that it may often be employed at the expense of task efficiency.     

THE DEVELOPMENT AND GENERALIZATION OF DELAYED IMITATION1

An individual's behavior can be identified as imitative if it temporally follows the behavior of another individual and if its topography is controlled by the demonstrated behavior [Baer, Peterson, and Sherman (Journal of the Experimental Analysis of Behavior, 1967, 10 , 405–416)]. This definition takes into account both temporal and topographical characteristics of the behavior in question. More recent research in the area of imitation has interpreted the temporal component of the above definition differentially by limiting imitation to those topographically similar responses occurring within 3, 5, or 10 sec after a model's demonstration. Yet, Gewirtz and Stingle (Psychological Review, 1968, 75 , 375–397) pointed out that much of the imitation seen in young children is not of this immediate nature, but instead occurs sometime after a model's response. They further suggest that this type of imitative behavior can be characterized as a response class and is susceptible to development and modification as a function of consequences delivered to subjects contingent on this type of delayed responding. Four retarded children, three initially imitative and one nonimitative, were individually trained to imitate a number of motor responses in an immediate and a delayed fashion. Immediate imitation was defined as a response similar to a model's demonstration occurring within 5 sec after the model's demonstration; delayed imitation was defined as a response similar to a model's demonstration occurring more than 5 sec, but not more than 25 sec, after the model's demonstration. A reversal (ABAB) design was employed to examine the experimental development of a generalized delayed imitative repertoire. Untrained probe responses were demonstrated to subjects systematically through the ongoing training. Generalized immediate and delayed imitation were observed in each subject; this generalization was restricted to the type of imitation currently undergoing training. This development of a generalized imitation repertoire was observed in each subject. That is, these subjects imitated some responses that had never been specifically trained. More importantly, a training package consisting of prompting, fading, and consequences for delayed imitation functioned to develop generalized delayed imitation. These data exemplify a special case of generalization that was a function of the most recent training history of immediate or delayed imitation. The reversal design demonstrated that imitations of nontrained models were either delayed or immediate, depending upon which form of imitation was currently receiving training. Therefore, for each form of imitation trained, delayed or immediate, a corresponding response class was demonstrated. These data relate to data reported by Garcia, Baer, and Firestone (Journal of Applied Behavior Analysis, 1971, 4 , 101–112). The association lies in the proposition that there are identifiable boundaries of generalized imitation and that these boundaries are functionally related to previous training histories.     

Explaining outcome type interactions with frame: Aspiration level and the value function

Research on framing effects has revealed cases where the type of outcome at risk (e.g., human lives vs. animal lives) affects the magnitude of the framing effect. Some authors have appealed to the shape of the value function as predicting when framing effects will occur: The more valuable the outcome type, the more nonlinear its value function, and the larger the resulting framing effect (Levin & Chapman, 1990). However, having a more or less nonlinear value function cannot explain situations in which participants strongly prefer the same option in both frames. Another factor that may be at work in these types of outcome effects is an aspiration level (AL; Lopes, 1987; Schneider, 1992), which determines how acceptable the options are and combines (or competes) with the risk attitude encouraged by frame. The results described here indicate that differences in the shape of the value function between outcome types are evident but are inconsistent between framed losses and gains, though nonlinearity in the value function can be increased with a manipulation that also encourages framing effects. The results also demonstrate that an AL can lead to the same predominant risk preference in the positive and negative frame. These findings indicate that the shape of the value function and the AL each play a role in outcome type interactions with frame, and in some cases, a combination of the two factors may be at work.