On the other hand: Increased cortical activation to human versus mechanical hands in infants.

There is a large body of work demonstrating that infants are sensitive to the distinction between human and mechanical entities from the early months of life, and have different expectations for the way these entities move and interact. The current work investigates the extent to which the functional organization of the immature brain reflects these early emerging sensitivities. Infants aged 8months watched two kinds of hands (human or mechanical) engage in two kinds of events (one with a functional outcome and one without). Using functional near-infrared spectroscopy (fNIRS), we assessed hemodynamic activation in the left and right temporal and temporal-occipital cortex in response to these events. The neuroimaging data revealed a significantly greater increase in activation in the right middle-posterior temporal cortex to events executed by the human than the mechanical hand; the event in which the hand engaged (function or non-function) did not significantly influence hemodynamic responses. In comparison, the left middle-temporal cortex showed significantly greater activation to events executed by the human than mechanical hand, but only when the events were functionally relevant. That is, the left middle-posterior temporal cortex responded selectively to human (as compared to mechanical) agents, but only in the context of functionally relevant actions on objects. These results reveal that the immature brain is functionally specialized to support infants' processing of human and non-human agents as distinct entities. These results also shed light on the cognitive and cortical mechanisms that guide infants' learning about agentive action and object function.

Cortical Activation to Social and Mechanical Stimuli in the Infant Brain.

From the early days of life infants distinguish between social and non-social physical entities and have different expectations for the way these two entities should move and interact. At the same time, we know very little about the cortical systems that support this early emerging ability. The goal of the current research was to assess the extent to which infant's processing of social and non-social physical entities is mediated by distinct information processing systems in the temporal cortex. Using a cross-sectional design, infants aged 6-9 months (Experiment 1) and 11-18 months (Experiment 2) were presented with two types of events: social interaction and mechanical interaction. In the social interaction event (patterned after Hamlin et al., 2007), an entity with googly eyes, hair tufts, and an implied goal of moving up the hill was either helped up, or pushed down, a hill through the actions of another social entity. In the mechanical interaction event, the googly eyes and hair tufts were replaced with vertical black dots and a hook and clasp, and the objects moved up or down the hill via mechanical interactions. FNIRS was used to measure activation from temporal cortex while infants viewed the test events. In both age groups, viewing social and mechanical interaction events elicited different patterns of activation in the right temporal cortex, although responses were more specialized in the older age group. Activation was not obtained in these areas when the objects moved in synchrony without interacting, suggesting that the causal nature of the interaction events may be responsible, in part, to the results obtained. This is one of the few fNIRS studies that has investigated age-related patterns of cortical activation and the first to provide insight into the functional development of networks specialized for processing of social and non-social physical entities engaged in interaction events.

Cortical responses to shape-from-motion stimuli in the infant.

Our ability to extract three-dimensional (3-D) object structure from motion-carried information is a basic visual capacity that is fundamental to object perception. Despite a rich body of behavioral work demonstrating that infants are sensitive to motion-carried information from the early months of life, little is known about the cortical networks that support infants' use of motion-carried information to extract 3-D object structure. This study assessed patterns of cortical activation in infants aged 4 to 6 months as they viewed two types of visual stimuli: (a) shape-from-motion (SFM) displays, where coherent motion of randomly distributed dots gave rise to the percept of 3-D shape and (b) random motion (RM) displays, where dots' motions lacked a coherent structure and gave rise to the percept of randomly moving dots. Functional near-infrared spectroscopy was used to assess activation in occipital, inferior parietal, and posterior temporal cortex. The optical imaging data revealed differential responding to SFM and RM in lower level object processing areas than typically observed in the adult. Possible explanations for this pattern of results are considered.

Corrigendum: Functional Activation in the Ventral Object Processing Pathway during the First Year.

[This corrects the article on p. 180 in vol. 9, PMID: 26778979.].

Functional Activation in the Ventral Object Processing Pathway during the First Year.

Infants' capacity to represent objects in visual working memory changes substantially during the first year of life. There is a growing body of research focused on identifying neural mechanisms that support this emerging capacity, and the extent to which visual object processing elicits different patterns of cortical activation in the infant as compared to the adult. Recent studies have identified areas in temporal and occipital cortex that mediate infants' developing capacity to track objects on the basis of their featural properties. The current research (Experiments 1 and 2) assessed patterns of activation in posterior temporal cortex and occipital cortex using fNIRS in infants 3-13 months of age as they viewed occlusion events. In the occlusion events, either the same object or featurally distinct objects emerged to each side of a screen. The outcome of these studies, combined, revealed that in infants 3-6 months, posterior temporal cortex was activated to all events, regardless of the featural properties of the objects and whether the event involved one object or two (featurally distinct) objects. Infants 7-8 infants months showed a waning posterior temporal response and by 10-13 months this response was negligible. Additional analysis showed that the age groups did not differ in their visual attention to the events and that changes in HbO were better explained by age in days than head circumference. In contrast to posterior temporal cortex, robust activation was obtained in occipital cortex across all ages tested. One interpretation of these results is that they reflect pruning of the visual object-processing network during the first year. The functional contribution of occipital and posterior temporal cortex, along with higher-level temporal areas, to infants' capacity to keep track of distinct entities in visual working memory is discussed.

Object processing in the infant: lessons from neuroscience.

Object identification is a fundamental cognitive capacity that forms the basis for complex thought and behavior. The adult cortex is organized into functionally distinct visual object-processing pathways that mediate this ability. Insights into the origin of these pathways have begun to emerge through the use of neuroimaging techniques with infant populations. The outcome of this work supports the view that, from the early days of life, object-processing pathways are organized in a way that resembles that of the adult. At the same time, theoretically important changes in patterns of cortical activation are observed during the first year. These findings lead to a new understanding of the cognitive and neural architecture in infants that supports their emerging object-processing capacities.

fNIRS in the developmental sciences.

With the introduction of functional near-infrared spectroscopy (fNIRS) into the experimental setting, developmental scientists have, for the first time, the capacity to investigate the functional activation of the infant brain in awake, engaged participants. The advantages of fNIRS clearly outweigh the limitations, and a description of how this technology is implemented in infant populations is provided. Most fNIRS research falls into one of three content domains: object processing, processing of biologically and socially relevant information, and language development. Within these domains, there are ongoing debates about the origins and development of human knowledge, making early neuroimaging particularly advantageous. The use of fNIRS has allowed investigators to begin to identify the localization of early object, social, and linguistic knowledge in the immature brain and the ways in which this changes with time and experience. In addition, there is a small but growing body of research that provides insight into the neural mechanisms that support and facilitate learning during the first year of life. At the same time, as with any emerging field, there are limitations to the conclusions that can be drawn on the basis of current findings. We offer suggestions as to how to optimize the use of this technology to answer questions of theoretical and practical importance to developmental scientists.

[A ten-year risk evaluation study in Catania hospital operating rooms]. / Dal monitoraggio alla valutazione del rischio in sala operatoria: risultati di un'indagine decennale negli ospedali catanesi.

Previous studies conducted in Catania hospitals have revealed a high burden of contamination in the air of operating rooms and have recommended measures to improve air quality. In this study we verified the effectiveness of the undertaken measures. Furthermore we evaluated the possibility of using microclimatic parameters as "markers" of operating room contamination. Changes made to ventilation systems and to waste gas scavenging systems in the monitored operating rooms were remarkably effective. Microclimatic conditions and degree of chemical contamination improved over time; nevertheless airflow velocity values were found to be insufficient and nitrous oxide values, in some cases, remained slightly elevated. A significant correlation was observed only between some nitrous oxide values and relative humidity. Monitoring important marker levels is useful for correctly evaluating operating room thermal, chemical and microbiological air quality.