Between 12- and 14 months of age infants begin to use another's direction of gaze and affective expression in learning about various objects and events. What is not well understood is how long infants' behaviour towards a previously unfamiliar object continues to be influenced following their participation in circumstances of social referencing. In this experiment, we examined infants' sensitivity to an adult's direction of gaze and their visual preference for one of two objects following a 5-min, 1-day, or 1-month delay. Ninety-six 12-month-olds participated. For half of the infants during habituation (i.e., familiarization), the adults' direction of gaze was directed towards an unfamiliar object (look condition). For the remaining half of the infants during habituation, the adults' direction of gaze was directed away from the unfamiliar object (look-away condition). All infants were habituated to two events. One event consisted of an adult looking towards (look condition) or away from (look-away condition) an object while facially and vocally conveying a positive affective expression. The second event consisted of the same adult looking towards or away from a different object while conveying a disgusted affective expression. Following the habituation phase and a 5-min, 1-day, or 1-month delay, infants' visual preference was assessed. During the visual preference phase, infants saw the two objects side by side where the adult conveying the affective expression was not visible. Results of the visual preference phase indicate that infants in the look condition showed a significant preference for object previously paired with the positive affect following a 5-min and 1-day delay. No significant visual preference was found in the look condition following a 1-month delay. No significant preferences were found at any retention interval in the look-away condition. Results are discussed in terms of early learning, social referencing, and early memory.

Infants' unitary perception of their multisensory world, including learning from people (faces and speech), hinges on temporal synchrony. Despite its importance, relatively little work has investigated the brain processes involved in infants' perception of temporal synchrony. In two experiments, we examined event-related brain potentials (ERPs) to asynchronous and synchronous audio-visual speech in infants. Both experiments showed the early auditory P2 was greater for the synchronously presented pairings and later attentional processing (Nc) was greater for asynchronous pairings. In addition, dynamic stimuli used in Experiment 2 produced a greater early visual response (N1) to the asynchronous condition and an enhanced memory-related slow wave (PSW) later for the synchronous condition. These results suggest that, like adults, auditory-visual integration for young infants begins early during sensory processing rather than later during higher-level cognitive processing. However, unlike adults, infants' brain responses may be biased towards synchrony. Furthermore, effects of attentional and memory processing confirm interpretations of behavioral looking patterns suggesting infants find synchrony more familiar.

This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants' memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter,& R. Flom, 2004) detection of and memory for nonredundantly specified properties, including the visual orientation of an event, are facilitated in unimodal stimulation and attenuated in bimodal stimulation in early development. Later in development, however, nonredundantly specified properties can be perceived and remembered in both multimodal and unimodal stimulation. The current study extended tests of these predictions to the domain of memory in infants of 3, 5, and 9 months of age. Consistent with predictions of the intersensory redundancy hypothesis, in unimodal stimulation, memory for visual orientation emerged by 5 months and remained stable across age, whereas in bimodal stimulation, memory did not emerge until 9 months of age. Memory for orientation was evident even after a 1-month delay and was expressed as a shifting preference, from novelty to null to familiarity, across increasing retention time, consistent with Bahrick and colleagues' four-phase model of attention. Together, these findings indicate that infant memory for nonredundantly specified properties of events is a consequence of selective attention to those event properties and is facilitated in unimodal stimulation. Memory for nonredundantly specified properties thus emerges in unimodal stimulation, is later extended to bimodal stimulation, and lasts across a period of at least 1 month.(PsycINFO Database Record (c) 2010 APA, all rights reserved).

Behavioral work demonstrates human infants are sensitive to a host of intersensory properties and this sensitivity promotes early learning and memory. However, little is known regarding the neural basis of this ability in infants. Using event-related potentials (ERPs) with infants and adults, we show that during passive viewing auditory evoked brain responses are increased with the presence of simultaneous visual stimulation. Results converge with previous adult neuroimaging studies, single-cell recordings in nonhuman animals, and behavioral studies with human infants to provide evidence for an elevated status of multisensory stimulation in infancy. Furthermore, these results may provide a neural marker of multisensory audio-visual processing in infants that can be used to test developmental theories of how information is integrated across the senses to form a unitary perception of the world.(c) 2009 Wiley Periodicals, Inc.

In 2000, the number of elderly citizens in the United States was 35 million, an increase of 3.7 million (11%) since 1990. Of these older adults, approximately 1.3 million (4%) have a low vision impairment. Older adults make up two-thirds of those diagnosed with a visual impairment. Low vision impairment, which is different from the typical vision changes associated with aging, occurs because of a chronic visual disorder that cannot be corrected medically, surgically, or with conventional eyeglasses, most often resulting in disability. The leading causes of low vision impairment are diabetic retinopathy, cataract, glaucoma, and age-related macular degeneration. Combined with the other physical changes associated with aging, the development of a low vision impairment further challenges the functional performance and safety of those 65 and older. Furthermore, the psychological impact from the physical changes accompanying aging is compounded for those with a low vision impairment. In response to the health needs of all age groups, Healthy People 2010 has established overarching goals to increase quality and years of healthy life and eliminate health disparities. An interdisciplinary course for allied health students was developed to support future health care providers in improving quality of life for older adults with low vision and help decrease health disparities in this population. This paper reports on the pilot experience with this course.

From birth, human infants are able to perceive a wide range of intersensory relationships. The current experiment examined whether infants between 6 months and 24 months old perceive the intermodal relationship between aggressive and nonaggressive canine vocalizations (i.e., barks) and appropriate canine facial expressions. Infants simultaneously viewed static aggressive and nonaggressive expressions of the same canine and heard an aggressive or nonaggressive bark. Results indicate that 6-month-olds perceived the intermodal relationship for aggressive and nonaggressive barks and the appropriate expression. Results also revealed that in older but not younger infants, the initial or first looks were directed toward the appropriate expression and that older infants also looked proportionately longer to the incongruent expression during the latter half of the test trials. Findings are discussed in terms of perceptual narrowing and the effects of familiarity and experience.(PsycINFO Database Record (c) 2009 APA, all rights reserved).

According to the intersensory redundancy hypothesis (IRH), during early development, perception of nonredundantly specified properties is facilitated in unimodal stimulation as compared with bimodal stimulation. Later in development, attention becomes more flexible and infants can detect nonredundantly specified properties in both unimodal and bimodal stimulation. This study tested these predictions by assessing the development of infants' sensitivity to the orientation of an object striking a surface, information that is nonredundantly specified in visual and in audiovisual stimulation. Infants of 3, 5, and 8 months were habituated to unimodal visual or bimodal, synchronous, audiovisual films of a hammer tapping a rhythm in 1 of 2 orientations (upward vs. downward). Results demonstrated an Age x Condition interaction, where younger infants (3 and 5 months) detected the orientation change in unimodal but not bimodal stimulation, whereas older infants (8 months) detected the change in both types of stimulation. Further, in a control study, 3-month-olds detected the orientation change when bimodal stimulation was asynchronous, demonstrating that temporal synchrony impaired performance in the bimodal condition. These findings converge with those of prior studies and support predictions of the IRH.

Infants can detect information specifying affect in infant- and adult-directed speech, familiar and unfamiliar facial expressions, and in point-light displays of facial expressions. We examined 3-, 5-, 7-, and 9-month-olds' discrimination of musical excerpts judged by adults and preschoolers as happy and sad. In Experiment 1, using an infant-controlled habituation procedure, 3-, 5-, 7-, and 9-month-olds heard three musical excerpts that were rated as either happy or sad. Following habituation, infants were presented with two new musical excerpts from the other affect group. Nine-month-olds discriminated the musical excerpts rated as affectively different. Five- and seven-month-olds discriminated the happy and sad excerpts when they were habituated to sad excerpts but not when they were habituated to happy excerpts. Three-month-olds showed no evidence of discriminating the sad and happy excerpts. In Experiment 2, 5-, 7-, and 9-month-olds were presented with two new musical excerpts from the same affective group as the habituation excerpts. At no age did infants discriminate these novel, yet affectively similar, musical excerpts. In Experiment 3, we examined 5-, 7-, and 9-month-olds' discrimination of individual excerpts rated as affectively similar. Only the 9-month-olds discriminated the affectively similar individual excerpts. Results are discussed in terms of infants' ability to discriminate affect across a variety of events and its relevance for later social-communicative development.

18- and 24-month-olds' ability to discriminate gender-stereotyped activities was assessed. Using a preferential looking paradigm, toddlers viewed male and female actors performing masculine and feminine-stereotyped activities. Consistent with our predictions, and previous research, 24-month-olds, but not 18-month-olds, looked longer at the gender-inconsistent activities than the gender-consistent activities. Results are discussed in terms of toddlers emerging gender stereotypes and perception of everyday events.

This research examined the developmental course of infants' ability to perceive affect in bimodal (audiovisual) and unimodal (auditory and visual) displays of a woman speaking. According to the intersensory redundancy hypothesis (L. E. Bahrick, R. Lickliter,& R. Flom, 2004), detection of amodal properties is facilitated in multimodal stimulation and attenuated in unimodal stimulation. Later in development, however, attention becomes more flexible, and amodal properties can be perceived in both multimodal and unimodal stimulation. The authors tested these predictions by assessing 3-, 4-, 5-, and 7-month-olds' discrimination of affect. Results demonstrated that in bimodal stimulation, discrimination of affect emerged by 4 months and remained stable across age. However, in unimodal stimulation, detection of affect emerged gradually, with sensitivity to auditory stimulation emerging at 5 months and visual stimulation at 7 months. Further temporal synchrony between faces and voices was necessary for younger infants' discrimination of affect. Across development, infants first perceive affect in multimodal stimulation through detecting amodal properties, and later their perception of affect is extended to unimodal auditory and visual stimulation. Implications for social development, including joint attention and social referencing, are considered.((c) 2006 APA, all rights reserved).