Spatial updating of virtual displays

In four experiments, we examined observers' ability to locate objects in virtual displays while rotating to new perspectives. In Experiment 1, participants updated the locations of previously seen landmarks in a display while rotating themselves to new views (viewer task) or while rotating the display itself (display task). Updating was faster and more accurate in the viewer task than in the display task. In Experiment 2, we compared updating performance during active and passive self-rotation. Participants rotated themselves in a swivel chair (active task) or were rotated in the chair by the experimenter (passive task). A minimal advantage was found for the active task. In the final experiments, we tested similar manipulations with an asymmetrical display. In Experiment 3, updating during the viewer task was again superior to updating during the display task. In Experiment 4, we found no difference in updating between active and passive self-movement. These results are discussed in terms of differences in sources of extraretinal information available in each movement condition.     

Spatial updating in superimposed real and virtual environments

Wang (2004) showed that people do not always simultaneously update their relationships to real and imagined environments in a dual-environment situation. Employing the same paradigm, we examined whether spatial updating operates on virtual reality as it does on a real or fictitious environment. Participants learned target locations in a real room and a virtual kitchen. Then they turned to face targets either in the room or in the kitchen, while blindfolded, and pointed to the targets before and after turning. Participants kept track of their orientation in both environments equally efficiently, regardless of explicit instructions. In contrast, when the real environment was described verbally but not directly perceived, participants automatically updated the virtual kitchen but not the room. These results suggest that people automatically update a virtual environment as they do a real one when the two environments are superimposed. The automaticity of spatial updating is discussed.     

Visual short-term memory in the first year of life: capacity and recency effects.

A span task was developed to assess the amount of information infants could hold in short-term memory. In this task, infants were presented with up to 4 items in succession and then tested for recognition by successively pairing each item with a novel one. A large sample of full-terms and low-birth-weight preterms (< 1,750 g) was tested longitudinally, at 5, 7, and 12 months of age. Results were similar for both groups: (a) Longer spans were more difficult, especially at the 2 younger ages; (b) memory capacity increased over the 1st year of life--whereas less than 25% of the sample could hold as many as 3-4 items in mind at once at the younger ages, nearly half could do so by 12 months of age; (c) there was a marked recency effect (greater memory for the final item) for spans of 3 and 4 at all ages; and (d) there were modest cross-age correlations, indicating that individual differences in memory capacity showed some stability from age to age.     

Social cognition in the first year

Although the study of infancy has answered many important questions about the human capacity for social cognition, the relatively young field of developmental social cognition is far from reaching its adulthood. With the merging of developmental, behavioral and neurocognitive sciences, some growing pains are in store. New work demonstrates that research into early social cognitive development must integrate various research fields and methods in order to achieve a more robust understanding of the nature and parameters of human social cognition.     

Spatial updating in virtual reality: the sufficiency of visual information

Robust and effortless spatial orientation critically relies on "automatic and obligatory spatial updating", a largely automatized and reflex-like process that transforms our mental egocentric representation of the immediate surroundings during ego-motions. A rapid pointing paradigm was used to assess automatic/obligatory spatial updating after visually displayed upright rotations with or without concomitant physical rotations using a motion platform. Visual stimuli displaying a natural, subject-known scene proved sufficient for enabling automatic and obligatory spatial updating, irrespective of concurrent physical motions. This challenges the prevailing notion that visual cues alone are insufficient for enabling such spatial updating of rotations, and that vestibular/proprioceptive cues are both required and sufficient. Displaying optic flow devoid of landmarks during the motion and pointing phase was insufficient for enabling automatic spatial updating, but could not be entirely ignored either. Interestingly, additional physical motion cues hardly improved performance, and were insufficient for affording automatic spatial updating. The results are discussed in the context of the mental transformation hypothesis and the sensorimotor interference hypothesis, which associates difficulties in imagined perspective switches to interference between the sensorimotor and cognitive (to-be-imagined) perspective.     

The control of training and transfer effects in the Minnesota Spatial Relations and other tasks

An experiment was carried out to demonstrate transfer of training in preschool children on tasks where transfer had previously been demonstrated in different populations. No evidence for transfer was found in any of the three tasks employed. The possibility that this finding was due to the lack of appropriate controls for the effects of specific training was examined using three groups to provide base-lines for the effects of practice, cognitive stimulation and social intervention. No significant differences were found either at post-test or follow-up between the specific training group and the control groups. A second experiment controlled for the effects of pre-testing. It was found that considerable transfer occurred from the pre-test trial to the first training trial. It appeared that one trial was sufficient to allow subjects to develop a strategy which was appropriate for both the training and transfer materials. Experiments of this type can clearly indicate whether or not some basic processes can be modified by means of short-term intervention and have implications for inducing longer-term benefits.     

Lack of set size effects in spatial updating: Evidence for offline updating

Four experiments required participants to keep track of the locations of (i.e., update) 1, 2, 3, 4, 6, 8, 10, or 15 target objects after rotating. Across all conditions, updating was unaffected by set size. Although some traditional set size effects (i.e., a linear increase of latency with memory load) were observed under some conditions, these effects were independent of the updating process. Patterns of data and participant strategies were inconsistent with the common view of spatial updating as an online process. Instead, the authors concluded that participants formed enduring, long-term memory representations of the layouts at learning that were used to reconstruct spatial information about the layouts as needed (i.e., offline updating). These results support M. Amorim, S. Glasauer, K. Corpinot, and A. Berthoz's (1997) 2-system model of spatial updating that includes both online and offline updating.     

Facial experience during the first year

Parents of 2-, 5-, 8-, and 11-month-olds used two scales we developed to provide information about their infants' facial experience with familiar and unfamiliar individuals during one week. Results showed large discrepancies in the race, sex, and age of faces that infants experience during their first year with the majority of their facial experience being with their primary caregiver, females, and other individuals of the same-race and age as their primary caregiver. The infant's age and an unfamiliar individual's sex were predictive of their time spent interacting with one another. Moreover, an unfamiliar individual's sex was predictive of the attention infants allocated during social interactions. Differences in frequency and length of interactions with certain types of faces, as well as in infant attention toward certain individuals, all likely contribute to the development of expertise in processing commonly experienced face types and deficiencies in processing less commonly experienced face types.     

Bilingualism in infancy: first steps in perception and comprehension

Many children grow up in bilingual families and acquire two first languages. Emerging research is advancing the view that the capacity to acquire language can be applied equally to two languages as to one but that bilingual and monolingual acquisition nonetheless differ in some nontrivial ways. To probe the first steps toward acquisition, researchers recently have begun to use experimental methods to study preverbal bilingual infants. We review the literature in this growing field, focusing on how infants growing up bilingual use surface acoustic information to separate, categorize and begin to learn their two languages. These new data invite the expansion of standard linguistic theories to account for how a single architecture can support the acquisition of two languages simultaneously.     

The development of referential offering in the first year

The ontogeny of referential offers was examined in a longitudinal, within dyad case study of two mother–infant pairs. A combination of microanalytic and qualitative methodologies was employed in describing the functions and morphology of this gesture, as well as its temporal and sequential organization with a number of infant and maternal behaviours. Offers were found to emerge from repetitive, exploratory play routines that provide infants with alternative visual perspectives on objects, and were facilitated by mothers' support of infants' immature attentional, motoric and arousal regulation capacities. Offers were observed to co. occur with maternal behaviours that direct and maintain infants' attention to objects. Our observations suggest that offers are transformed through guided interactions into conventional communicative gestures. Offering arises as mothers become part of the infants' exploratory play routines, gradually changing the function of the behaviour of the infants. These observations are consistent with dynamic systems models of development.     

Maternal adjustment during pregnancy and the infant''s first year

The study aimed at establishing the predictive validity of clinical observations and interview data collected during late pregnancy. 40 pregnant women from a Swedish non-risk population were interviewed about psychological and somatic well-being, significant relationships and delivery expectations. Pregnancy adjustment was also assessed by the maternal health clinic midwife. After the birth of the child, the mothers were interviewed in the delivery hospital and during home visits when the infants were 2 and 6 weeks, and 4, 8 and 12 months old. The results showed that pregnancy adjustment, as assessed by the mothers themselves, acted as a significant predictor of the early maternal adjustment and the adjustment towards the end of the infant's first year. The midwives' assessments significantly predicted maternal adjustment towards the end of the first year. Pregnancy data did not correlate with maternal delivery experiences.     

Order effects in belief updating with consistent and inconsistent evidence

The current study tests for the presence of differential order effects in evaluation tasks with consistent and inconsistent evidence as predicted by the Hogarth and Einhorn (1992) belief-adjustment model. The results, based on both between-subjects and within-subjects experiments, demonstrate that there were significant recency effects with inconsistent evidence as predicted, larger recency effects when the inconsistent evidence was farther apart in subjective value as predicted, and significant recency effects even when subjects were given training designed to both help them understand the task as completely as possible and to be better able to assess the pieces of evidence. By including a within-subjects design, we were able to demonstrate that the difference in subjective value between two pieces of evidence is the primary factor influencing the magnitude of the recency effect, regardless of whether the evidence is consistent or inconsistent. This latter finding is unique and contrary to previous research and theory.     

Parents’ differential susceptibility to the effects of marital quality on sensitivity across the first year

The current investigation examined the differential susceptibility of parents to the effects of marital quality on changes in parenting. We predicted that parents who were high on the personality constructs Negative Affect and Constraint would be more susceptible to the effects of marital quality on their level of sensitivity. Sensitivity was assessed at 3.5 and 13 months for both mothers and fathers during a triadic interaction. Consistent with the differential susceptibility theory, results suggested that when mothers were high on Negative Affect and when fathers were high on Constraint, their marital quality was associated with changes in sensitivity. This investigation suggests that personality factors may create “vulnerabilities” in parents that make them differentially susceptible to the effects of the family environment on parenting.     

Spatial updating of multiple targets: Comparison of younger and older adults

When walking without vision, people mentally keep track of the directions and distances of previously viewed objects, a process called spatial updating. The current experiment indicates that while people across a large age range are able to update multiple targets in memory without perceptual support, aging negatively affects accuracy, precision, and decision time. Participants (20 to 80 years of age) viewed one, three, or six targets (colored lights) on the floor of a dimly lit room. Then, without vision, they walked to a target designated by color, either directly or indirectly (via a forward turning point). The younger adults’ final stopping points were both accurate (near target) and precise (narrowly dispersed), but updating performance did degrade slightly with the number of targets. Older adults’ performance was consistently worse than the younger group, but the lack of interaction between age and memory load indicates that the effect of age on performance was not further exacerbated by a greater number of targets. The number of targets also significantly increased the latency required to turn toward the designated target for both age groups. Taken together, results extend previous work showing impressive updating performance by younger adults, with novel findings showing that older adults manifest small but consistent degradation of updating performance of multitarget arrays.     

Detection of visual-tactile contingency in the first year after birth

It is well documented that in the first year after birth, infants are able to identify self-performed actions. This ability has been regarded as the basis of conscious self-perception. However, it is not yet known whether infants are also sensitive to aspects of the self when they cannot control the sensory feedback by means of self-performed actions. Therefore, we investigated the contribution of visual–tactile contingency to self-perception in infants. In Experiment 1, 7- and 10-month-olds were presented with two video displays of lifelike baby doll legs. The infant’s left leg was stroked contingently with only one of the video displays. The results showed that 7- and 10-month-olds looked significantly longer at the contingent display than at the non-contingent display. Experiment 2 was conducted to investigate the role of morphological characteristics in contingency detection. Ten-month-olds were presented with video displays of two neutral objects (i.e., oblong wooden blocks of approximately the same size as the doll legs) being stroked in the same way as in Experiment 1. No preference was found for either the contingent or the non-contingent display but our results confirm a significant decrease in looking time to the contingent display compared to Experiment 1. These results indicate that detection of visual–tactile contingency as one important aspect of self-perception is present very early in ontogeny. Furthermore, this ability appears to be limited to the perception of objects that strongly resemble the infant’s body, suggesting an early sensitivity to the morphology of one’s own body.     

Spatial updating of locations specified by 3-d sound and spatial language

Blind and blindfolded sighted observers were presented with auditory stimuli specifying target locations. The stimulus was either sound from a loudspeaker or spatial language (e.g., "2 o'clock, 16 ft"). On each trial, an observer attempted to walk to the target location along a direct or indirect path. The ability to mentally keep track of the target location without concurrent perceptual information about it (spatial updating) was assessed in terms of the separation between the stopping points for the 2 paths. Updating performance was very nearly the same for the 2 modalities, indicating that once an internal representation of a location has been determined, subsequent updating performance is nearly independent of the modality used to specify the representation.