The understanding of congruent and incongruent referential gaze in 17-month-old infants: an eye-tracking study comparing human and robot.

Several studies have shown that the human gaze, but not the robot gaze, has significant effects on infant social cognition and facilitate social engagement. The present study investigates early understanding of the referential nature of gaze by comparing-through the eye-tracking technique-infants' response to human and robot's gaze. Data were acquired on thirty-two 17-month-old infants, watching four video clips, where either a human or a humanoid robot performed an action on a target. The agent's gaze was either turned to the target (congruent) or opposite to it (incongruent). The results generally showed that, independent of the agent, the infants attended longer at the face area compared to the hand and target. Additionally, the effect of referential gaze on infants' attention to the target was greater when infants watched the human compared to the robot's action. These results suggest the presence, in infants, of two distinct levels of gaze-following mechanisms: one recognizing the other as a potential interactive partner, the second recognizing partner's agency. In this study, infants recognized the robot as a potential interactive partner, whereas ascribed agency more readily to the human, thus suggesting that the process of generalizability of gazing behaviour to non-humans is not immediate.

Dexamethasone implant in diabetic macular edema in real-life situations.

PURPOSE: To report outcome of eyes with recalcitrant and naive eyes with diabetic macular edema (DME) treated with intravitreal dexamethasone implants (Ozurdex) injection. METHODS: Retrospective multicenter data analysis of eyes with DME treated with Ozurdex implant and with minimum follow-up of at least one year after the first implant. Data collected included demographic details, history of presenting illness, past treatment history, clinical examination details including visual acuity at presentation, and follow-up with imaging and treatment details. Paired sample t-test was used to measure mean differences between pre- and post-implant values obtained at baseline and last follow-up. RESULTS: A total of 79 eyes (62 subjects) were included. Sixty-four eyes had been previously treated; 15 eyes were naive. Among the previously treated eyes, mean interval between first Ozurdex injection and any previous treatment was 7.69±8.2 months. In naive eyes, the visual acuity improved from baseline 0.58±0.25 to 0.44±0.33 logMAR at last follow-up (P=0.05). In eyes that had been previously treated, the improvement was from 0.65±0.34 at baseline to 0.48±0.35 logMAR (P=0.01). Mean treatment-free interval was 6.5±4.5 months. Nine eyes were steroid responder with controlled intraocular pressure (IOP), none showed any spike in IOP during the follow-up period. CONCLUSIONS: Ozurdex implant could be a good alternative for recalcitrant as well as naive eyes with DME. The visual gain after initial implant injection was fairly maintained, with additional treatment usually after 6 months in naive eyes. Ozurdex appeared safe even in steroid responders with good control of IOP with antiglaucoma medications.

Bayes factor of model selection validates FLMP.

The fuzzy logical model of perception (FLMP; Massaro, 1998) has been extremely successful at describing performance across a wide range of ecological domains as well as for a broad spectrum of individuals. An important issue is whether this descriptive ability is theoretically informative or whether it simply reflects the model's ability to describe a wider range of possible outcomes. Previous tests and contrasts of this model with others have been adjudicated on the basis of both a root mean square deviation (RMSD) for goodness-of-fit and an observed RMSD relative to a benchmark RMSD if the model was indeed correct. We extend the model evaluation by another technique called Bayes factor (Kass & Raftery, 1995; Myung & Pitt, 1997). The FLMP maintains its significant descriptive advantage with this new criterion. In a series of simulations, the RMSD also accurately recovers the correct model under actual experimental conditions. When additional variability was added to the results, the models continued to be recoverable. In addition to its descriptive accuracy, RMSD should not be ignored in model testing because it can be justified theoretically and provides a direct and meaningful index of goodness-of-fit. We also make the case for the necessity of free parameters in model testing. Finally, using Newton's law of universal gravitation as an analogy, we argue that it might not be valid to expect a model's fit to be invariant across the whole range of possible parameter values for the model. We advocate that model selection should be analogous to perceptual judgment, which is characterized by the optimal use of multiple sources of information (e.g., the FLMP). Conclusions about models should be based on several selection criteria.

Modeling face identification processing in children and adults.

Two face identification experiments were carried out to study whether and how children (5-year-olds) and adults integrate single facial features to identify faces. Using the paradigm of the Fuzzy Logical Model of Perception each experiment used the same expanded factorial design, with three levels of eyes variations crossed with three levels of mouth variations as well as their corresponding half-face conditions. In Experiment 1, an integration of facial features was observed in adults only. But, in adjusting the salience of the features varied, the results of Experiment 2 indicate that children and adults evaluated and integrated information from both features to identify a face. A weighted Fuzzy Logical Model of Perception fit the judgments significantly better than a Single Channel Model and questions previous claims of holistic face processing. Although no developmental differences in the stage of the integration of facial information were observable, differences between children and adults appeared in the information used for face identification.

Pulmonary alveolus formation: critical period, retinoid regulation and plasticity.

Pulmonary alveoli, the lung's gas-exchange structures, are formed in part by subdivision (septation) of the saccules that constitute the gas-exchange region of the immature lung. Although little is known about the regulation of septation, relatively recent studies show: (1) all-trans retinoic acid (RA) treatment of newborn rats increases septation and prevents the inhibition of septation produced by treatment of newborn rats with dexamethasone, a glucocorticosteroid hormone; (2) treatment with RA of adult rats that have elastase-induced emphysema increases lung elastic recoil, induces the formation of alveoli, and increases volume-corrected alveolar surface area; and (3) in tight-skin mice, which have a genetic failure of septation, and in rats in which septation had previously been prevented by treatment with dexamethasone, treatment with RA partially rescues the failed septation. These findings raise the possibility that treatment with RA will induce the formation of alveoli in humans with pulmonary emphysema.

Retinoic acid receptor-beta: an endogenous inhibitor of the perinatal formation of pulmonary alveoli.

Pulmonary alveoli are formed, in part, by subdivision (septation) of the gas-exchange saccules of the immature lung. Septation is developmentally regulated, and failure to septate at the appropriate time is not followed by delayed spontaneous septation. We report retinoic acid receptor (RAR) beta knockout mice exhibit premature septation; in addition, they form alveoli twice as fast as wild-type mice during the period of septation but at the same rate as wild-type mice thereafter. Consistent with the perinatal effect of RARbeta knockout, RARbeta agonist treatment of newborn rats impairs septation. These results 1) identify RARbeta as the first recognized endogenous signaling that inhibits septation, 2) demonstrate premature onset of septation may be induced, and 3) show the molecular signaling regulating alveolus formation differs during and after the period of septation. Suppressing perinatal RARbeta signaling by RARbeta antagonists may offer a novel, nonsurgical, means of preventing, or remediating, failed septation in prematurely born children.

Tests of auditory-visual integration efficiency within the framework of the fuzzy logical model of perception.

The fuzzy logical model of perception [FLMP, Massaro, Perceiving Talking Faces: From Speech Perception to a Behavioral Principle (MIT Press, Cambridge, MA, 1998)] has been extremely successful at describing performance across a wide range of ecological domains as well as for a broad spectrum of individuals. Because the model predicts optimal or maximally efficient integration, an important issue is whether this is the case for most individuals. Three databases are evaluated to determine to what extent a significant quantitative improvement in predictive ability can be obtained if integration is assumed to be somewhat inefficient. For the most part, there were no significant signs of inefficient integration. The previous differences found by Grant and Seitz [J. Acoust. Soc. Am. 104, 2438-2450 (1998)] must be due to their measures of efficiency, which appear to be invalid and/or conflate information with integration efficiency. Finally, the descriptive ability of the FLMP is shown to be theoretically informative and not simply the model's ability to describe any possible outcome.

Retinoic acid treatment partially rescues failed septation in rats and in mice.

Pulmonary alveoli are formed in part by subdivision (septation) of the gas-exchange saccules of the immature lung. Septation results in smaller, more numerous structures (alveoli) and is developmentally regulated in mammals including humans, rats, and mice; if it fails to occur at the appropriate time, there is no spontaneous post hoc septation nor has there been a means of inducing septation after it has failed to occur. We measured lung volume, the volume of individual alveoli, and alveolar surface area and calculated alveolar number in neonatal rats in which septation had been blocked by treatment with a glucocorticosteroid hormone and in adult tight-skin mice that have a genetic failure of septation. We tested the hypothesis that treatment with all-trans retinoic acid induces post hoc septation. In both models of failed septation, hence in two species, and in immature and adult animals, treatment with all-trans retinoic acid induced post hoc septation, offering the possibility of a similar effect in premature infants.

Regulation of lung manganese superoxide dismutase: species variation in response to lipopolysaccharide.

Lipopolysaccharide (LPS) treatment increases survival of rats, but not of mice, during hyperoxia. Manganese superoxide dismutase (Mn SOD) in the lung plays a critical role in LPS-induced tolerance to hyperoxia in rats. Therefore, we now compared the response of lung Mn SOD with treatment of mice and rats with LPS. LPS treatment of rats increased Mn SOD activity and protein concentration, did not change its specific activity, increased Mn SOD mRNA concentration 35-fold, and elevated Mn SOD synthesis 50% without changing general protein synthesis. LPS treatment of mice did not alter any of these parameters except for a 16-fold increase in Mn SOD mRNA concentration. Mn SOD translational efficiency (synthesis/mRNA concentration) was diminished 93% in rat lung and 76% in mouse lung by treatment with LPS. However, the absolute translational efficiency was twofold higher in lungs of LPS-treated rats than in lungs of LPS-treated mice. The failure of LPS to raise Mn SOD activity in mouse lungs is due, at least in part, to a smaller increase in Mn SOD mRNA and lower translational efficiency in LPS-treated mice than in LPS-treated rats.

Speech perception in perceivers with hearing loss: synergy of multiple modalities.

Although we would expect that the role of visible speech in multimodal speech perception would have the greatest relevance to individuals with hearing impairment, relatively few analytic studies have been done with these participants. Their adequate understanding of spoken language usually requires information from several modalities or other sources of information. The framework of the fuzzy logical model of perception (FLMP) is used to assess how individuals with hearing impairment evaluate and integrate multiple sources of information. Given this framework, a distinction can be made between information and information processing. Within this framework, we can ask what information differences and information-processing differences exist among individuals with normal hearing and those with hearing impairment. Four experimental studies from the literature are analyzed to address these questions. Test items are presented under both unimodal and bimodal conditions. Of central interest is the nature of the bimodal performance as a function of the unimodal performance. The findings show that, although information differences obviously exist across different populations, their information processing involved in pattern recognition appears to be the same and is well described by the FLMP.

Gene expression of cellular retinoid-binding proteins: modulation by retinoic acid and dexamethasone in postnatal rat lung.

In rats, septation of gas-exchange saccules occurs during the first 2 postnatal weeks; dexamethasone (DEX) treatment irreversibly impairs septation, and treatment with all-trans retinoic acid (RA) prevents the DEX-induced inhibition of septation. Cellular retinoic acid-binding protein I (CRABP I) and cellular retinol-binding protein I (CRBP I) are important modulators of the cellular metabolism of retinoids. In the present study, therefore, we measured the mRNA concentration of CRABP I and CRBP I in lungs of neonatal rats. In untreated rats, CRABP I and CRBP I mRNA peaked at postnatal d 8, indicating that CRABP I and CRBP I are developmentally regulated at least in part at a pretranslational level during lung septation. Daily treatment of 3- to 8-d-old rats with RA (500 microg/kg/d) had no effect on the level of CRABP I mRNA; treatment with DEX (0.25 microg/d) from d 4 to 8 caused a decrease in CRABP I mRNA that was not prevented by concomitant treatment with RA. These findings suggest that a decrease in CRABP I expression may be important in the DEX-induced block of septation but not in the prevention by RA of DEX-induced inhibition of septation. RA treatment caused an increase of CRBP I mRNA; conversely, treatment with DEX caused a decrease in CRBP I mRNA that was prevented by concomitant treatment with RA. These data suggest CRBP I may play a role in RA-induced septation, in the inhibition of septation caused by DEX, and in the ability of RA to prevent DEX-blocked septation.

Laterality in visual speech perception.

The lateralization of visual speech perception was examined in 3 experiments. Participants were presented with a realistic computer-animated face articulating 1 of 4 consonant-vowel syllables without sound. The face appeared at 1 of 5 locations in the visual field. The participants' task was to identify each test syllable. To prevent eye movement during the presentation of the face, participants had to carry out a fixation task simultaneously with the speechreading task. In one study, an eccentricity effect was found along with a small but significant difference in favor of the right visual field (left hemisphere). The same results were found with the face articulating nonlinguistic mouth movements (e.g., kiss). These results suggest that the left-hemisphere advantage is based on the processing of dynamic visual information rather than on the extraction of linguistic significance from facial movements.

Molecular mechanisms of antioxidant enzyme expression in lung during exposure to and recovery from hyperoxia.

Manganese superoxide dismutase (MnSOD) activity falls approximately 50% in lung during 48 h of exposure of adult rats to > 95% O2 (L. B. Clerch and D. Massaro. J. Clin. Invest. 91: 499-508, 1993). We now show that hyperoxia also decreased MnSOD activity in lungs of adult baboons, making the phenomenon potentially more important to humans. In rats, a decrease in lung MnSOD activity during an initial 48 h of exposure to > 95% O2 and its increase during an immediately subsequent 24 h in air were due to decreases and increases, respectively, in MnSOD specific activity and synthesis rate; the latter was due to altered translational efficiency. The concentration in the lung of copper-zinc superoxide dismutase mRNA, catalase mRNA, and glutathione peroxidase mRNA, unchanged during the initial 48 h of exposure to O2, rose approximately twofold during reexposure to O2 after 24 h in air. The demonstration that the fall in MnSOD activity is translationally and posttranslationally regulated during the initial exposure to hyperoxia suggests that gene transfer to increase MnSOD activity in hyperoxic lungs may also require therapy that maintains translational efficiency and MnSOD specific activity.

Speechreading in the akinetopsic patient, L.M.

Patient L.M. has a well-documented, long-standing and profound deficit in the perception of visual movement, following bilateral lesions of area V5 (visual movement cortex). Speechreading was explored in this patient in order to clarify the extent to which the extraction of dynamic information from facial actions is necessary for speechreading. Since L.M. is able to identify biological motion from point-light displays to whole-body forms and has some limited visual motion capabilities, we expected that some speechreading of faces in action would be possible in this patient. L.M.'s reading of natural speech was severely impaired, despite unimpaired ability to recognize speech-patterns from face photographs and reasonable identification of monosyllables produced in isolation. She was unable to track multisyllabic utterances reliably and was insensitive to vision when incongruent audiovisual speech syllables were shown. Point-light displays of speech were as poorly read as whole face displays. Rate of presentation was critical to her performance. With speech, as with other visual events, including tracking the direction of gaze and of hand-movement sequences, she could report actions that unfolded slowly (approximately one event per 2 s). In line with this, she was poor at reporting whether seen speech rate was normal, fast (double-speed) or slow (half-speed). L.M.'s debility is the converse of that reported for a patient with lesions primarily to V4 (H.J.A.), who is unable to speechread photographs of faces but can speechread moving faces. The visual analysis of both form and motion is required for speechreading; the neural systems that support these analyses are discussed.

Retinoic acid treatment abrogates elastase-induced pulmonary emphysema in rats.

Pulmonary emphysema is a common disease in which destruction of the lung's gas-exchange structures (alveoli) leads to inadequate oxygenation, disability and frequently death; lung transplantation provides its only remediation. Because treatment of normal rats with all-trans-retinoic acid increases the number of alveoli, we tested whether a similar effect would occur in rats with emphysema. Elastase was instilled into rat lungs, producing changes characteristic of human and experimental emphysema: increased lung volume reflecting a loss of lung elastic recoil, larger but fewer alveoli and diminished volume-corrected alveolar surface area due to destruction of alveolar walls. Treatment with all-trans-retinoic acid reversed these changes providing nonsurgical remediation of emphysema and suggesting the possibility of a similar effect in humans.

Featural evaluation, integration, and judgment of facial affect.

The paradigm of the fuzzy logical model of perception (FLMP) is extended to the domain of perception and recognition of facial affect. Two experiments were performed using a highly realistic computer-generated face varying on 2 features of facial affect. Each experiment used the same expanded factorial design, with 5 levels of brow deflection crossed with 5 levels of mouth deflection, as well as their corresponding half-face conditions, for a total stimulus set of 35 faces. Experiment 1 used a 2-alternative, forced-choice paradigm (either happy or angry), whereas Experiment 2 used 9 rating steps from happy to angry. Results indicate that participants evaluated and integrated information from both features to perceive affective expressions. Both choice probabilities and ratings showed that the influence of 1 feature was greater to the extent that the other feature was ambiguous. The FLMP fit the judgments from both experiments significantly better than an additive model. Our results question previous claims of categorical and holistic perception of affect.

Perception of visible speech: influence of spatial quantization.

Visible speech reading was studied to determine which features are functional and to test several models of pattern recognition. Nine test syllables differing in their initial consonant were presented in intact form or under various levels of spatial quantization. Performance decreased in increasing quantization but remained relatively good at moderate levels of degradation. Different models were tested against the confusion matrices. Six features were identified as functional in distinguishing among the nine consonant--vowel syllables. These features were used as sources of information in a fuzzy-logical model of perception and an additive model. The fuzzy-logical model provided a significantly better description of the confusion matrices, showing that speech reading is analogous to other domains of pattern recognition such as face recognition and facial-affect perception.