Longitudinal Continuity in Understanding and Production of Giving-Related Behavior From Infancy to Childhood.

Infants have an early understanding of giving (the transfer of an item by one agent to another), but little is known about individual differences in these abilities or their developmental outcomes. Here, 9-month-olds (N = 59) showing clearer neural processing (Event-related potential, ERP) of a give-me gesture also evidenced a stronger reaction (pupil dilation) to an inappropriate response to a give-me gesture, and at 2 years were more likely to give in response to a give-me gesture. None of the differences in understanding and production of giving-related behaviors were associated with other sociocognitive variables investigated: language, gaze-following, and nongiving helping. The early developmental continuity in understanding and production of giving behavior is consistent with the great importance of giving for humans throughout the life span.

Links between action perception and action production in 10-week-old infants.

In order to understand how experience of an action alters functional brain responses to visual information, we examined the effects of reflex walking on how 10-week-old infants processed biological motion. We gave experience of the reflex walk to half the participants, and did not give this experience to the other half of the sample. The participant's electrical brain activity in response to viewing upright and inverted walking and crawling movements indicated the detection of biological motion only for that group which experience the reflex walk, as evidenced by parietal electrode greater positivity for the upright than the inverted condition. This effect was observed only for the walking stimuli. This study suggests that parietal regions are associated with the perception of biological motion even at 9-11 weeks. Further, this result strongly suggests that experience refines the perception of biological motion and that at 10 weeks of age, the link between action perception and action production is tightly woven.

Sensitivity to structure in action sequences: An infant event-related potential study.

Infants are sensitive to structure and patterns within continuous streams of sensory input. This sensitivity relies on statistical learning, the ability to detect predictable regularities in spatial and temporal sequences. Recent evidence has shown that infants can detect statistical regularities in action sequences they observe, but little is known about the neural process that give rise to this ability. In the current experiment, we combined electroencephalography (EEG) with eye-tracking to identify electrophysiological markers that indicate whether 8-11-month-old infants detect violations to learned regularities in action sequences, and to relate these markers to behavioral measures of anticipation during learning. In a learning phase, infants observed an actor performing a sequence featuring two deterministic pairs embedded within an otherwise random sequence. Thus, the first action of each pair was predictive of what would occur next. One of the pairs caused an action-effect, whereas the second did not. In a subsequent test phase, infants observed another sequence that included deviant pairs, violating the previously observed action pairs. Event-related potential (ERP) responses were analyzed and compared between the deviant and the original action pairs. Findings reveal that infants demonstrated a greater Negative central (Nc) ERP response to the deviant actions for the pair that caused the action-effect, which was consistent with their visual anticipations during the learning phase. Findings are discussed in terms of the neural and behavioral processes underlying perception and learning of structured action sequences.

Event-related potentials discriminate familiar and unusual goal outcomes in 5-month-olds and adults.

Previous event-related potential (ERP) work has indicated that the neural processing of action sequences develops with age. Although adults and 9-month-olds use a semantic processing system, perceiving actions activates attentional processes in 7-month-olds. However, presenting a sequence of action context, action execution and action conclusion could challenge infants' developing working memory capacities. A shortened stimulus presentation of a highly familiar action, presenting only the action conclusion of an eating action, may therefore enable semantic processing in even younger infants. The present study examined neural correlates of the processing of expected and unexpected action conclusions in adults and infants at 5 months of age. We analyzed ERP components reflecting semantic processing (N400), attentional processes (negative central in infants; P1, N2 in adults) and the infant positive slow wave (PSW), a marker of familiarity. In infants, the PSW was enhanced on left frontal channels in response to unexpected as compared to the expected outcomes. We did not find differences between conditions in ERP waves reflecting semantic processing or overt attentional mechanisms. In adults, in addition to differences in attentional processes on the P1 and the N2, an N400 occurred only in response to the unexpected action outcome, suggesting semantic processing taking place even without a complete action sequence being present. Results indicate that infants are already sensitive to differences in action outcomes, although the underlying mechanism which is based on familiarity is relatively rudimentary when contrasted with adults. This finding points toward different cognitive mechanisms being involved in action processing during development. (PsycINFO Database Record

Semantic processing of actions at 9months is linked to language proficiency at 9 and 18months.

The current study uses event-related potential methodologies to investigate how social-cognitive processes in preverbal infants relate to language performance. We assessed 9-month-olds' understanding of the semantic structure of actions via an N400 event-related potential (ERP) response to action sequences that contained expected and unexpected outcomes. At 9 and 18months of age, infants' language abilities were measured using the Swedish Early Communicative Development Inventory (SECDI). Here we show that 9-month-olds' understanding of the semantic structure of actions, evidenced in an N400 ERP response to action sequences with unexpected outcomes, is related to language comprehension scores at 9months and is related to language production scores at 18months of age. Infants who showed a selective N400 response to unexpected action outcomes are those who are classed as above mean in their language proficiency. The results provide evidence that language performance is related to the ability to detect and interpret human actions at 9months of age. This study suggests that some basic cognitive mechanisms are involved in the processing of sequential events that are shared between two conceptually different cognitive domains and that pre-linguistic social understanding skills and language proficiency are linked to one another.

The neural basis of non-verbal communication-enhanced processing of perceived give-me gestures in 9-month-old girls.

This study investigated the neural basis of non-verbal communication. Event-related potentials were recorded while 29 nine-month-old infants were presented with a give-me gesture (experimental condition) and the same hand shape but rotated 90°, resulting in a non-communicative hand configuration (control condition). We found different responses in amplitude between the two conditions, captured in the P400 ERP component. Moreover, the size of this effect was modulated by participants' sex, with girls generally demonstrating a larger relative difference between the two conditions than boys.

The neuropsychology of infants' pro-social preferences.

The current study is the first to investigate neural correlates of infants' detection of pro- and antisocial agents. Differences in ERP component P400 over posterior temporal areas were found during 6-month-olds' observation of helping and hindering agents (Experiment 1), but not during observation of identically moving agents that did not help or hinder (Experiment 2). The results demonstrate that the P400 component indexes activation of infants' memories of previously perceived interactions between social agents. This leads to suggest that similar processes might be involved in infants' processing of pro- and antisocial agents and other social perception processes (encoding gaze direction, goal directed grasping and pointing).

Discrimination of animate and inanimate motion in 9-month-old infants: an ERP study.

Simple geometric shapes moving in a self-propelled manner, and violating Newtonian laws of motion by acting against gravitational forces tend to induce a judgement that an object is animate. Objects that change their motion only due to external causes are more likely judged as inanimate. How the developing brain is employed in the perception of animacy in early ontogeny is currently unknown. The aim of this study was to use ERP techniques to determine if the negative central component (Nc), a waveform related to attention allocation, was differentially affected when an infant observed animate or inanimate motion. Short animated movies comprising a marble moving along a marble run either in an animate or an inanimate manner were presented to 15 infants who were 9 months of age. The ERPs were time-locked to a still frame representing animate or inanimate motion that was displayed following each movie. We found that 9-month-olds are able to discriminate between animate and inanimate motion based on motion cues alone and most likely allocate more attentional resources to the inanimate motion. The present data contribute to our understanding of the animate-inanimate distinction and the Nc as a correlate of infant cognitive processing.

The neural correlates of passively viewed sequences of true and false beliefs.

The ability to infer other people's mental states such as desires, emotions, intentions and beliefs is essential for successful social interactions, and it is usually referred to as theory of mind (ToM). In particular, the ability to detect and understand that people have beliefs about reality that may be false is considered an important hallmark of ToM. This experiment reports on the results of 18 participants who viewed photographic sequences of an actress performing actions as a consequence of true and false beliefs. Consistent with prior work, results from the passive viewing of stimuli depicting true belief indicated an increased response over frontal, central and parietal regions when compared with the amplitude for the false belief condition. These results show that (i) frontal activity is required for processing false belief tasks and (ii) parietal effects reported in previous studies to reflect specific cognitive process of monitoring others' beliefs can be elicited in the absence of an explicit instruction for mentalizing.