Cold-Restraint Stress-Induced Ultrasonic Vocalization as a Novel Tool to Measure Anxiety in Mice.

Ultrasonic vocalization (USVs) is a promising tool to measure behavioral anxiety in rodents as USV recording is noninvasive, behaviorally relevant, ethological, and reproducible. Studies reporting the effects of stress-induced USVs in adult mice remain limited and debated. We investigated the conditions under which mice emit aversive USVs and evaluated the effects of psychiatric drugs on stress-induced USVs. Male C57BL/6J mice were used. USVs during entire stress sessions were recorded according to their frequency. To investigate the effect of psychiatric drugs on USVs, the number of USVs under cold-restraint stress conditions before and after drug administration was compared. Immediately after stress exposure, blood samples were collected and plasma corticosterone levels were measured. The combination of cold and restraint stress conditions significantly increased the USV numbers and plasma corticosterone levels compared with each stress alone. A benzodiazepine anxiolytic (midazolam) and δ-opioid receptor agonist putative anxiolytic (KNT-127) significantly reduced the stress-induced USV number and plasma corticosterone levels; however, a monoaminergic antidepressant (duloxetine) and N-methyl-D-aspartic acid receptor antagonist antidepressant (ketamine) did not reduce the USV numbers. No changes were noted in the USV numbers after repeated exposure to cold-restraint stress on days 1 and 3. The suppressive effect of midazolam on day 3 was comparable to that on day 1. Stress-induced USV may be used as a quantitative measure of anxiety to systematically assess the effects of anxiolytics. Therefore, cold-restraint stress-induced USVs may be used as a novel tool to measure rodent anxiety and as a useful anxiolytic-screening system.

A longitudinal study of infant view-invariant face processing during the first 3-8 months of life.

View-invariant face processing emerges early in life. A previous study (Nakato et al., 2009) measured infant hemodynamic responses to faces from the frontal and profile views in the bilateral temporal areas, which have been reported to be involved in face processing using near-infrared spectroscopy. It was reported that 5-month-old infants showed increased oxyhemoglobin (oxy-Hb) responses to frontal faces, but not to profile faces. In contrast, 8-month-old infants displayed increased oxy-Hb responses to profile faces as well as to frontal faces. In this study, we used the experimental method developed in the previous study to investigate the development of view-invariant face processing, every month for 5 months (from the first 3-8 months of life). We longitudinally measured hemodynamic responses to faces from the frontal and profile views in 14 infants. The longitudinal measurements allowed us to investigate individual differences in each participant. We modeled each infant's hemodynamic oxy-Hb responses to frontal and profile faces using linear regression analysis. Processing of profile faces emerged later and underwent larger improvements than that of frontal faces. We also found an anticorrelation between the speed of improvement in face processing and the hemodynamic response to faces at the age of 3- months. Group analysis of the averaged hemodynamic data from the 14 infants using linear regression revealed that the processing of profile faces emerged between 5 and 6 months of age. Infant view-invariant face processing developed first for frontal faces. This was followed by the emergence of processing of profile faces.

Wollaston's effect in infants: Do infants integrate eye and head information in gaze perception?

The current study examined infants' sensitivity to Wollaston's effect: When identical eyes are placed in differently angled faces, the perceived gaze direction shifts toward the orientation of the face such that physically, the direct gaze is perceived as averted toward the orientation of the face. Consistent with Wollaston's effect, we found that looking toward direct and averted gaze by 4- to 5- and 7- to 8-month-olds (n = 40) was affected by the head orientation context. These results demonstrate that infants aged 4 to 5 and 7 to 8 months integrate eye and head information to perceive another's gaze direction. In light of recent psychophysical findings, the current results suggest that the visual function supporting constant gaze perception across head rotation is already at work by 4 to 5 months of age.

A phase II study of bevacizumab with modified OPTIMOX1 as first-line therapy for metastatic colorectal cancer: the TCOG-GI 0802 study.

BACKGROUND: Although bevacizumab plus FOLFOX is a standard treatment for metastatic colorectal cancer, oxaliplatin must be withdrawn in many patients because of cumulative neurotoxicity. We postulated that a reduced dose of oxaliplatin and modified treatment schedule would prolong the time to treatment failure and evaluated bevacizumab combined with a modified OPTIMOX1 regimen (mOPTIMOX1, oxaliplatin dose: 85 mg/m(2)). METHODS: Eligible patients had a histologically confirmed diagnosis of metastatic colorectal cancer and a performance status of 0-1. Patients were excluded if they had grade 1 or higher peripheral sensory neuropathy or had previously received chemotherapy for metastatic colorectal cancer. Patients received bevacizumab plus mFOLFOX6 every 2 weeks for 6 cycles, followed by 12 cycles of a simplified biweekly regimen of leucovorin and fluorouracil (sLV5FU2) plus bevacizumab. Oxaliplatin was then reintroduced, and bevacizumab plus mFOLFOX6 was continued until progressive disease. RESULTS: The median duration of disease control was 11.7 months (95 % confidence interval [CI], 9.7-13.5 months). The median overall survival was 23.1 months (95 % CI, 18.8-27.9 months). The overall response rate according to both the RECIST and WHO criteria was 51.3 %. The most common grade 3 or 4 toxicities were neutropaenia (32.5 %), hypertension (17.5 %), leukocytopaenia, sensory neuropathy, and diarrhoea (10.0 %). There were no treatment-related deaths. CONCLUSIONS: Bevacizumab plus mFOLFOX6 was well tolerated, and patients could continue chemotherapy for longer than with conventional FOLFOX regimens. This regimen might be an effective treatment option for patients with metastatic colorectal cancer.

Neurotypicals with higher autistic traits have delayed visual processing of an approaching life-sized avatar's gait: an event-related potentials study.

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder, which is reportedly related to difficulties in the visual processing of human motion, such as biological motion and gestures. Moreover, neurotypical (here, we mention it as individuals without a diagnosis) adults with autistic traits are clumsier than those without autistic traits when passing by others. It is still unclear whether the clumsiness derived from atypical visual processing of another's approaching gait motion. We aim to address this question by investigating the association between autistic traits in neurotypical adults and the visual processing of an approaching life-sized avatar's gait. Methods: We clarified a typical visual motion processing and autistic traits in daily life in 26 neurotypical adults by analyzing the subthreshold autism trait questionnaire (SATQ) score, a 24-item self-report scale of ASD, and event-related potentials (ERPs) in response to walking motion of a passing avatar. Videos of walking life-sized virtual avatars approaching and retreating were presented as visual stimuli. Results and discussion: The association between the participants' SATQ scores and the latencies and amplitudes of the ERPs was examined. ERP components (N170 and P200) components were identified at T5 and T6 electrodes. Participants reporting higher SATQ scores had longer latencies of P200 at T6 and lower amplitudes of P200 at T5 and T6 electrodes for the approaching avatar than those reporting lower SATQ scores. These findings indicate that adults with autistic traits have delayed and less sensitive visual processing of the approaching avatar. It suggests that while passing another person, these individuals have atypical visual processing of their approach. This study may contribute to elucidating autistic traits from the perspective of visual processing in an environment simulating daily life.

Gait Perception of Life-Size Point-Light Walker is Associated with Autistic Traits: Evidence from Event-Related Evoked Potentials.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by a combination of atypicalities in social cognition. Previous studies showed that people with autistic traits have atypicality in motion perception on a point-light display by measuring visual event-related potentials (ERPs). Although some studies have focused on the association between motion perception and autistic traits, visual ERPs to biological motion as large as actual person have not been investigated. Measuring brain activity in a real-life environment help us to understand the difficulties showed in daily life by people with autistic traits. In this study, we investigated the association between gait perception and autistic traits by measuring ERPs during video observation of approaching and receding life-sized point-light walkers (PLW s). ERPs were measured using an 8-channel EEG system in 22 adults. The multiple regression analyses were conducted to assess association between the Subthreshold Autism Trait Questionnaire (SATQ) score and the ERP amplitude or latency. As the results, we found that the higher SATQ score could be explained by the longer latency of N1 on the occipitotemporal area. These findings suggested that people with autistic traits have difficulty in perceiving the approach of others in daily life.

High-frequency ultrasound exposure improves depressive-like behavior in an olfactory bulbectomized rat model of depression.

OBJECTIVES: According to previous studies, ultrasound exposure appears to be a noninvasive method for modulating brain activity related to cognition and consciousness; however, its effects on emotional states remain unclear. Therefore, an animal model is required in which the effects and effect mechanisms of ultrasound exposure can be investigated. Thus, we used olfactory bulbectomized rats as an animal model of depression and investigated their emotional state following ultrasound exposure. METHODS: In male Wistar/ST olfactory bulbectomized rats, hyperemotionality was evaluated according to hyperemotionality scoring and the scores before and after 24-h ultrasound exposure were compared. Elevated plus maze (EPM) tests were also conducted after 24-h ultrasound exposure, and blood samples were collected in which plasma corticosterone concentrations were measured. RESULTS: Following exposure to high-frequency (~50 kHz) ultrasound vocalizations (USVs) associated with the pleasant emotions of rats, the hyperemotionality scores of olfactory bulbectomized rats were significantly reduced. Additionally, the latency of the first entry into the open arm of the EPM was significantly decreased in USV-exposed olfactory bulbectomized rats, as were their plasma corticosterone levels. Furthermore, artificial ultrasound (50 kHz) at a similar frequency to that of USV also significantly decreased the hyperemotionality score of olfactory bulbectomized rats. CONCLUSIONS: Ultrasound exposure improved depressive-like behavior in olfactory bulbectomized rats and reduced their plasma corticosterone levels. Thus, we recommend the use of olfactory bulbectomized rats as an animal model for investigating the effects and effect mechanisms of ultrasound exposure.

Correlation Between Gait Perception and Autistic Traits in the General Population: A Study on Event-Related Evoked Potentials.

Previous studies have shown that people with autistic traits have difficulties in motion perception, such as human gait as depicted on a point-light display. A recent study reported that adults with autism spectrum disorders showed atypical visual event-related evoked potentials (ERPs) in response to radial optic flow. To determine the correlation between gait perception and autistic traits in the general population, the present study recorded ERPs time-locked to the onset of approaching and receding point-light walkers. ERPs were measured using an 8-channel system in 19 adults and the correlation between the ERP components and the Subthreshold Autism Trait Questionnaire (SATQ) score were assessed to quantitatively measure autistic traits in the general population. The results showed that the higher SATQ score was, the longer the latency of the ERP component for an approaching walker was. In conclusion, people with autistic traits have trouble perceiving the approach of other people.

Hemodynamic response to familiar faces in children with ADHD.

BACKGROUND: School-age children with attention deficit hyperactivity disorder (ADHD) have difficulties in interpersonal relationships, in addition to impaired facial expression perception and recognition. For successful social interactions, the ability to discriminate between familiar and unfamiliar faces is critical. However, there are no published reports on the recognition of familiar and unfamiliar faces by children with ADHD. METHODS: We evaluated the neural correlates of familiar and unfamiliar facial recognition in children with ADHD compared to typically developing (TD) children. We used functional near-infrared spectroscopy (fNIRS) to measure hemodynamic responses on the bilateral temporal regions while participants looked at photographs of familiar and unfamiliar faces. Nine boys with ADHD and 14 age-matched TD boys participated in the study. fNIRS data were Z-scored prior to analysis. RESULTS: During familiar face processing, TD children only showed significant activity in the late phase, while ADHD children showed significant activity in both the early and late phases. Additionally, the boys with ADHD did not show right hemispheric lateralization to familiar faces. CONCLUSIONS: This study is the first to assess brain activity during familiar face processing in boys with ADHD using fNIRS. These findings of atypical patterns of brain activity in boys with ADHD may be related to social cognitive impairments from ADHD.

Nω -(Carboxymethyl)arginine Is One of the Dominant Advanced Glycation End Products in Glycated Collagens and Mouse Tissues.

Advanced glycation end products (AGEs) accumulate in proteins during aging in humans. In particular, the AGE structure Nω -(carboxymethyl)arginine (CMA) is produced by oxidation in glycated collagen, accounting for one of the major proteins detected in biological samples. In this study, we investigated the mechanism by which CMA is generated in collagen and detected CMA in collagen-rich tissues. When various protein samples were incubated with glucose, the CMA content, detected using a monoclonal antibody, increased in a time-dependent manner only in glycated collagen, whereas the formation of Nε -(carboxymethyl)lysine (CML), a major antigenic AGE, was detected in all glycated proteins. Dominant CMA formation in glycated collagen was also observed by electrospray ionization-liquid chromatography-tandem mass spectrometry (LC-MS/MS). During incubation of glucose with collagen, CMA formation was enhanced with increasing glucose concentration, whereas it was inhibited in the presence of dicarbonyl-trapping reagents and a metal chelator. CMA formation was also observed upon incubating collagen with glyoxal, and CMA was generated in a time-dependent manner when glyoxal was incubated with type I-IV collagens. To identify hotspots of CMA formation, tryptic digests of glycated collagen were applied to an affinity column conjugated with anti-CMA. Several CMA peptides that are important for recognition by integrins were detected by LC-MS/MS and amino acid sequence analyses. CMA formation on each sequence was confirmed by incubation of the synthesized peptides with glyoxal and ribose. LC-MS detected CMA in the mouse skin at a higher level than other AGEs. Furthermore, CMA accumulation was greater in the human aorta of older individuals. Overall, our study provides evidence that CMA is a representative AGE structure that serves as a useful index to reflect the oxidation and glycation of collagen.

Depression and anxiety in pet owners after a diagnosis of cancer in their pets: a cross-sectional study in Japan.

OBJECTIVE: To determine the presence and predictors of depression and anxiety in pet owners after a diagnosis of cancer in their pets. DESIGN: Cross-sectional study. SETTING: A veterinary medical centre specialised in oncology for dogs and cats and two primary veterinary clinics in Japan. PARTICIPANTS: The participants for analysis were 99 owners of a pet with cancer diagnosis received in the past 1-3 weeks and 94 owners of a healthy pet. MAIN OUTCOME MEASURES: Self-reported questionnaires were used to assess depression and anxiety. Depression was assessed using the Center of Epidemiologic Studies Depression Scale, and anxiety was measured by using the State-Trait Anxiety Inventory-Form JYZ. RESULTS: Depression scores were significantly higher in owners of a pet with cancer than owners of a healthy pet, even after adjustment for potential confounders (p<0.001). Within the owners of a pet with cancer, depression was significantly more common in those who were employed than those who were unemployed (p=0.048). State anxiety scores were significantly higher in owners of a pet with cancer than owners of a healthy pet, even after adjustment for potential confounders, including trait-anxiety scores (p<0.001). Furthermore, in owners of a pet with cancer, state anxiety was higher in owners with high trait anxiety (p<0.001) and in owners whose pets had a poor prognosis (p=0.027). CONCLUSION: The results indicate that some owners tended to become depressed and anxious after their pets had received a diagnosis of cancer. Employment may be a predictor of depression. High trait anxiety and a pet with a poor prognosis may increase owners' state anxiety. Including the pet in a family genogram and attention to the pet's health condition may be important considerations for family practice.

The effects of resistance training of swallowing muscles on dysphagia in older people: A cluster, randomized, controlled trial.

OBJECTIVE: This study examined the effects of resistance training of swallowing muscles in community-dwelling older individuals with dysphagia. METHODS: A cluster randomized controlled trial was performed in day-service and day-care facilities. The participants were older (≥65 y) community-dwelling individuals with dysphagia. The intervention group performed a tongue resistance exercise and a head flexion exercise against manual resistance. Both groups received a brochure on dysphagia rehabilitation. The primary endpoint was an improvement in dysphagia assessed by the Eating Assessment Tool (EAT-10) score. Tongue pressure was the secondary endpoint. RESULTS: Participants included 47 men and 57 women, with a mean age ± standard deviation of 80 ± 7 y. At baseline, the median EAT-10 score was 7 (interquartile range, 5-12). A total of 91 patients, 43 in the intervention group (8 clusters) versus 48 in the control group (11 clusters), were assessed postintervention. The percentage of participants with EAT-10 scores <3 was not statistically significantly different between the two groups (intervention group, 23% versus control group, 19%, P = 0.598). Postintervention median EAT-10 scores were 6 (interquartile range, 3-10) in each group (P = 0.665) and mean tongue pressure was 23.9 ± 10.0 versus 25.9 ± 10.9 kPa (P = 0.376). The intervention did not significantly affect the EAT-10 score or tongue pressure in a mixed effects random intercept model. The Mini Nutritional Assessment Short Form score correlated significantly with the postintervention EAT-10 score. CONCLUSIONS: Resistance training of swallowing muscles did not improve dysphagia in this study. Better nutritional status correlated independently with improved swallowing function.

Function of congruent facial responses to smiling and frowning.

The congruent facial response of a receiver may change a sender's facial display in subsequent facial communication. Senders were requested to smile and frown at a receiver of computer-synthesized animation and to rate how likeable the receiver was after the "interaction." It was observed that a congruent facial response maintained the sender's facial expression longer than an incongruent response did. The results of the questionnaire revealed that senders reported a greater likeability for smiling receivers than for those who frowned. Likeability ratings did not depend on the congruency of the receiver's response but simply on whether the receiver was smiling or frowning.

Validity and reliability of the Patient Centred Assessment Method for patient complexity and relationship with hospital length of stay: a prospective cohort study.

OBJECTIVES: Several instruments for evaluating patient complexity have been developed from a biopsychosocial perspective. Although relationships between the results obtained by these instruments and the length of stay in hospital have been examined, many instruments are complicated and not easy to use. The Patient Centred Assessment Method (PCAM) is a candidate for practical use. This study aimed to test the validity and reliability of the PCAM and examine the correlations between length of hospital stay and PCAM scores in a regional secondary care hospital in Japan. DESIGN: Prospective cohort study. PARTICIPANTS AND SETTING: Two hundred and one patients admitted to Ouji Coop Hospital between July 2014 and September 2014. MAIN PREDICTOR: PCAM total score in initial phase of hospital admission. MAIN OUTCOME: Length of stay in hospital. RESULTS: Among 201 patients (Female/Male=98/103) with mean (SD) age of 77.4±11.9 years, the mean PCAM score was 25±7.3 and mean (SD) length of stay in hospital (LOS) 34.1±40.9 days. Using exploratory factor analysis to examine construct validity, PCAM evidently has a two-factor structure, comprising medicine-oriented and patient-oriented complexity. The Spearman rank correlation coefficient for evaluating criterion-based validity between PCAM and INTERMED was 0.90. For reliability, Cronbach's alpha was 0.85. According to negative binomial regression analyses, PCAM scores are a statistically significant predictor (p<0.001) of LOS after adjusting for age, gender, Mini Nutritional Assessment Short-Form, Charlson Comorbidity Index, serum sodium concentration, total number of medications and whether public assistance was required. In another model, each factor in PCAM was independently correlated with length of stay in hospital after adjustment (medicine-oriented complexity: p=0.001, patient-oriented complexity: p=0.014). CONCLUSION: PCAM is a reliable and valid measurement of patient complexity and PCAM scores have a significant correlation with hospital length of stay.

Culture shapes 7-month-olds' perceptual strategies in discriminating facial expressions of emotion.

Emotional facial expressions are thought to have evolved because they play a crucial role in species' survival. From infancy, humans develop dedicated neural circuits [1] to exhibit and recognize a variety of facial expressions [2]. But there is increasing evidence that culture specifies when and how certain emotions can be expressed - social norms - and that the mature perceptual mechanisms used to transmit and decode the visual information from emotional signals differ between Western and Eastern adults [3-5]. Specifically, the mouth is more informative for transmitting emotional signals in Westerners and the eye region for Easterners [4], generating culture-specific fixation biases towards these features [5]. During development, it is recognized that cultural differences can be observed at the level of emotional reactivity and regulation [6], and to the culturally dominant modes of attention [7]. Nonetheless, to our knowledge no study has explored whether culture shapes the processing of facial emotional signals early in development. The data we report here show that, by 7 months, infants from both cultures visually discriminate facial expressions of emotion by relying on culturally distinct fixation strategies, resembling those used by the adults from the environment in which they develop [5].

Face Orientation and Motion Differently Affect the Deployment of Visual Attention in Newborns and 4-Month-Old Infants.

Orienting visual attention allows us to properly select relevant visual information from a noisy environment. Despite extensive investigation of the orienting of visual attention in infancy, it is unknown whether and how stimulus characteristics modulate the deployment of attention from birth to 4 months of age, a period in which the efficiency in orienting of attention improves dramatically. The aim of the present study was to compare 4-month-old infants' and newborns' ability to orient attention from central to peripheral stimuli that have the same or different attributes. In Experiment 1, all the stimuli were dynamic and the only attribute of the central and peripheral stimuli to be manipulated was face orientation. In Experiment 2, both face orientation and motion of the central and peripheral stimuli were contrasted. The number of valid trials and saccadic latency were measured at both ages. Our results demonstrated that the deployment of attention is mainly influenced by motion at birth, while it is also influenced by face orientation at 4-month of age. These findings provide insight into the development of the orienting visual attention in the first few months of life and suggest that maturation may be not the only factor that determines the developmental change in orienting visual attention from birth to 4 months.

Differences in the Pattern of Hemodynamic Response to Self-Face and Stranger-Face Images in Adolescents with Anorexia Nervosa: A Near-Infrared Spectroscopic Study.

There have been no reports concerning the self-face perception in patients with anorexia nervosa (AN). The purpose of this study was to compare the neuronal correlates of viewing self-face images (i.e. images of familiar face) and stranger-face images (i.e. images of an unfamiliar face) in female adolescents with and without AN. We used near-infrared spectroscopy (NIRS) to measure hemodynamic responses while the participants viewed full-color photographs of self-face and stranger-face. Fifteen females with AN (mean age, 13.8 years) and 15 age- and intelligence quotient (IQ)-matched female controls without AN (mean age, 13.1 years) participated in the study. The responses to photographs were compared with the baseline activation (response to white uniform blank). In the AN group, the concentration of oxygenated hemoglobin (oxy-Hb) significantly increased in the right temporal area during the presentation of both the self-face and stranger-face images compared with the baseline level. In contrast, in the control group, the concentration of oxy-Hb significantly increased in the right temporal area only during the presentation of the self-face image. To our knowledge the present study is the first report to assess brain activities during self-face and stranger-face perception among female adolescents with AN. There were different patterns of brain activation in response to the sight of the self-face and stranger-face images in female adolescents with AN and controls.

Involvement of intracellular glutathione in zinc deficiency-induced activation of hepatic stellate cells.

Hepatic stellate cells (HSC) play an important role in the development of liver cirrhosis. They are a major source of extracellular matrix and during fibrogenesis undergo an activation process characterized by increased proliferation and collagen synthesis. In this study, we investigated the anti-fibrogenic effect of zinc supplementation on zinc deficiency induced HSC activation. Isolated HSC were incubated with or without zinc chelator, diethylenetriamine penta-acetic acid (DTPA). Type I collagen expression in HSC was detected by immunohistochemistry. The involvement of glutathione (GSH) homeostasis in the anti-fibrogenic action of zinc was also investigated, as GSH is implicated in many cellular events, such as regulation of cell proliferation, remodeling of extracellular matrix and oxidative stress. Intracellular GSH was measured by HPLC. Enhanced type I collagen expression, apoptosis and cell cycle arrest were found in HSC when DTPA was added, but they were inhibited with supplementation with zinc. Zinc deficiency caused a reduction in intracellular GSH 8 h after the addition of DTPA compared with control levels. The results of this study show that in HSC, the chelation of zinc triggers a progression of collagen synthesis and this involves the depletion of intracellular GSH levels after the addition of DTPA.

[Concordance of facial reactions to facial expressions].

Participants watching a facial expression of emotion tend to respond with the same facial expression. This facial concordance is well known for happiness, but not for other emotions. The present study investigated whether facial expressions of basic six emotions induce facial concordance in participants by average-face method. Facial reactions of 20 subjects were videotaped while watching a facial expression of six emotions performed by amateur actors in a computer display. The six average faces were made from corresponding facial expression of emotions in the display. Newly chosen 62 subjects were asked to classify those average faces into six categories of emotion. The facial concordance was found for happiness and surprise, but not for disgust and fear. However, for average face of anger and that of sadness, classifications were divided into a few categories. This result suggests a possibility that an average faces might have included ambiguous or different faces. It may be necessary to conduct re-classification not with the average-face but with individual faces.

Infants recognize the subtle happiness expression.

Facial movement facilitates the recognition of facial expressions. While an intense expression is expressive enough to be recognized in a still image, a subtle expression can be recognized only in motion (Ambadar, Schooler, & Cohn, 2005, Psychological Science, 16, 403-410). The present study investigated whether infants recognize a subtle expression, and whether facial movement facilitates infants' recognition of a subtle expression. In experiment 1 4- to 7-month-old infants were tested for their spontaneous preference for a happy subtle expression rather than a neutral face, but they did not show a spontaneous preference. To confirm that infants did not recognize the static subtle expression, we conducted experiment 2 using the familiarization-novelty procedure. Infants were first familiarized with a static subtle happy expression. Following familiarization, they were presented with a pair of peak expressions of happiness and anger, but showed no significant novelty preference. In experiment 3 we presented the subtle expression dynamically. Infants were familiarized with a dynamic subtle expression and were tested for their novelty preference. The 6- to 7-month-olds showed a significant novelty preference, while 4- to 5-month-olds did not. These results suggest that infants can recognize the subtle expression only in dynamic presentation and that facial movement facilitates infants' recognition of facial expression.