Francesca Simion

Face perception and processing in early infancy: inborn predispositions and developmental changes

From birth it is critical for our survival to identify social agents and conspecifics. Among others stimuli, faces provide the required information. The present paper will review the mechanisms subserving face detection and face recognition, respectively, over development. In addition, the emergence of the functional and neural specialization for face processing as an experience-dependent process will be documented. Overall, the present work highlights the importance of both inborn predispositions and the exposure to certain experiences, shortly after birth, to drive the system to become functionally specialized to process faces in the first months of life.

Difference in Visual Social Predispositions Between Newborns at Low- and High-risk for Autism

Some key behavioural traits of Autism Spectrum Disorders (ASD) have been hypothesized to be due to impairments in the early activation of subcortical orienting mechanisms, which in typical development bias newborns to orient to relevant social visual stimuli. A challenge to testing this hypothesis is that autism is usually not diagnosed until a child is at least 3 years old. Here, we circumvented this difficulty by studying for the very first time, the predispositions to pay attention to social stimuli in newborns with a high familial risk of autism. Results showed that visual preferences to social stimuli strikingly differed between high-risk and low-risk newborns. Significant predictors for high-risk newborns were obtained and an accurate biomarker was identified. The results revealed early behavioural characteristics of newborns with familial risk for ASD, allowing for a prospective approach to the emergence of autism in early infancy.

Visual cues of motion that trigger animacy perception at birth: the case of self-propulsion.

Self-propelled motion is a powerful cue that conveys information that an object is animate. In this case, animate refers to an entitys capacity to initiate motion without an applied external force. Sensitivity to this motion cue is present in infants that are a few months old, but whether this sensitivity is experience-dependent or is already present at birth is unknown. Here, we tested newborns to examine whether predispositions to process self-produced motion cues underlying animacy perception were present soon after birth. We systematically manipulated the onset of motion by self-propulsion (Experiment 1) and the change in trajectory direction in the presence or absence of direct contact with an external object (Experiments 2 and 3) to investigate how these motion cues determine preference in newborns. Overall, data demonstrated that, at least at birth, the self-propelled onset of motion is a crucial visual cue that allowed newborns to differentiate between self- and non-self-propelled objects (Experiment 1) because when this cue was removed, newborns did not manifest any visual preference (Experiment 2), even if they were able to discriminate between the stimuli (Experiment 3). To our knowledge, this is the first study aimed at identifying sensitivity in human newborns to the most basic and rudimentary motion cues that reliably trigger perceptions of animacy in adults. Our findings are compatible with the hypothesis of the existence of inborn predispositions to visual cues of motion that trigger animacy perception in adults.

Walking direction triggers visuo-spatial orienting in 6-month-old infants and adults: An eye tracking study

The present study investigates whether the walking direction of a biological motion point-light display can trigger visuo-spatial attention in 6-month-old infants. A cueing paradigm and the recording of eye movements in a free viewing condition were employed. A control group of adults took part in the experiment. Participants were presented with a central point-light display depicting a walking human, followed by a single peripheral target. In experiment 1, the central biological motion stimulus depicting a walking human could be upright or upside-down and was facing either left or right. Results revealed that the latency of saccades toward the peripheral target was modulated by the congruency between the facing direction of the cue and the position of the target. In infants, as well as in adults, saccade latencies were shorter when the target appeared in the position signalled by the facing direction of the point-light walker (congruent trials) than when the target appeared in the contralateral position (incongruent trials). This cueing effect was present only when the biological motion cue was presented in the upright condition and not when the display was inverted. In experiment 2, a rolling point-light circle with unambiguous direction was adopted. Here, adults were influenced by the direction of the central cue. However no effect of congruency was found in infants. This result suggests that biological motion has a priority as a cue for spatial attention during development.

The Visual Search of an Illusory Figure: A Comparison between 6-Month-Old Infants and Adults

The aim of the present study was to investigate how perceptual binding and selective attention operate during infants and adults visual search of an illusory figure. An eye-tracker system was used to test adults and infants in two conditions: illusory and non-illusory (real). In the illusory condition, a Kanizsa triangle was embedded among distractor pacmen which did not generate illusory contours. In the non-illusory condition, a real triangle was included in the same pacmens display. The results showed that adults detected both the Kanizsa and the real figure automatically and without focal attention (experiment 1). In contrast, 6-month-old infants showed a pop-out effect only for the real figure (experiment 2). The failure of the illusory figure to trigger infants attention was not due to infants inability to perceive the illusory figure per se, as infants preferred the illusory figure over a non-illusory control stimulus in a classical preferential-looking task (experiment 3). Overall, these findings indicate that the illusory Kanizsa triangle triggers visual attention in adults, but not in infants, supporting evidence that at 6 months of age the binding processes involved in the perception of a Kanizsa figure do not operate in an adult-like manner.

A comparison between preterm and full-term infants' preference for faces

OBJECTIVEnVisual preference for faces at birth is the product of a multimodal sensory experience experienced by the fetus even during the gestational period. The ability to recognize faces allows an ecologically advantageous interaction with the social environment. However, perinatal events such as premature birth, may adversely affect the adequate development of this capacity. In this study, we evaluated the preference for facial stimuli in preterm infants within the first few hours after birth.nnnMETHODSnThis is a cross-sectional observational study of 59 newborns, 28 preterm and 31 full-term infants. The babies were assessed in the first hours of life, with two white boards in the shape of a head and neck: one with the drawing of a face similar to the human face (natural face), and one with the drawing of misaligned eyes, mouth and nose (distorted face). After the newborn fixated the eyes on the presented stimulus, it was slowly moved along the visual field. The recognition of the stimulus was considered present when the baby had eye or head movements toward the stimulus.nnnRESULTSnThe preterm infants, in addition to showing a lower occurrence of orientation movements for both stimuli, on average (1.8±1.1 to natural faces and 2.0±1.2 for distorted ones) also showed no preference for any of them (p=0.35). Full-term newborns showed a different behavior, in which they showed a preference for natural faces (p=0.002) and a higher number of orientations for the stimulus, for both natural (3.2±0.8) and distorted faces (2.5±0.9).nnnCONCLUSIONnPreterm newborns recognize facial stimuli and disclose no preference for natural faces, different from full-term newborns.

Newborns’ attention is driven by the translational movement

ABSTRACT The present study investigated whether 2-day-old newborns are able to discriminate two translating meaningless Point-Light Displays (PLD) videos, in which the shape of one of them changes compared to that of the other along the trajectory, independently from movement kinematics, and if this ability is present both when stimuli differed at the end or at the beginning of the movement. To manipulate the instant in which along the movement the difference between stimuli was evident, and to maintain every unspecific dissimilarity possibly determining the preference, videos were played in a loop either forward or backwards. In Experiment 1, PLD stimuli moved with natural accelerated-decelerated kinematics; in Experiment 2 they moved at constant velocity. Four groups of newborns were submitted to the preferential looking technique experiments. Results showed that newborns looked longer at natural kinematics and that, irrespective of the type of kinematics, they discriminated the two stimuli only when videos were played forward, that is, only when stimuli differed at the end of the movement. These data suggest that, independently from kinematics, movement translational components induce newborns to allocate attention at the end of the observed movement. Given the strict link between attention and eye movements, we suggest that this effect may bootstrap the system and give rise to proactive gaze, the typical gaze behaviour present during executed and observed goal-directed actions.