Experience-driven meaning affects lexical choices during language production

The role of meaning facets based on sensorimotor experiences is well-investigated in comprehension but has received little attention in language production research. In two experiments, we investigated whether experiential traces of space influenced lexical choices when participants completed visually-presented sentence fragments (e.g., ‘You are at the sea and you see a ...’) with spoken nouns (e.g., ‘dolphin’, ‘palm tree’). The words were presented consecutively in an ascending or descending direction, starting from the center of the screen. These physical spatial cues did not influence lexical choices. However, the produced nouns met the spatial characteristics of the broader sentence contexts such that the typical spatial locations of the produced noun referents were predicted by the location of the situations described by the sentence fragments (i. e., upper or lower sphere). By including distributional semantic similarity measures derived from computing cosine values between sentence nouns and produced nouns using a web-based text corpus, we show that the meaning dimension of ‘location in space’ guides lexical selection during speaking. We discuss the relation of this spatial meaning dimension to accounts of experientially grounded and usage-based theories of language processing and their combination in hybrid approaches. In doing so, we contribute to a more comprehensive understanding of the many facets of meaning processing during language production and their impact on the words we select to express verbal messages.

Judgments of Object Size and Distance across Different Virtual Reality Environments: A Preliminary Study

Emerging technologies offer the potential to expand the domain of the future workforce to extreme environments, such as outer space and alien terrains. To understand how humans navigate in such environments that lack familiar spatial cues this study examined spatial perception in three types of environments. The environments were simulated using virtual reality. We examined participants’ ability to estimate the size and distance of stimuli under conditions of minimal, moderate, or maximum visual cues, corresponding to an environment simulating outer space, an alien terrain, or a typical cityscape, respectively. The findings show underestimation of distance in both the maximum and the minimum visual cue environment but a tendency for overestimation of distance in the moderate environment. We further observed that depth estimation was substantially better in the minimum environment than in the other two environments. However, estimation of height was more accurate in the environment with maximum cues (cityscape) than the environment with minimum cues (outer space). More generally, our results suggest that familiar visual cues facilitated better estimation of size and distance than unfamiliar cues. In fact, the presence of unfamiliar, and perhaps misleading visual cues (characterizing the alien terrain environment), was more disruptive than an environment with a total absence of visual cues for distance and size perception. The findings have implications for training workers to better adapt to extreme environments.

Spatial and featural cue weighting in children’s developing object representations

To accurately represent an object, it must be individuated from the surrounding objects and then classified with the appropriate category or identity. To this end, adults flexibly weight different visual cues when perceiving objects. However, less is known about whether, and how, the weighting of visual object information changes over development. The current study examined how children use different types of information— spatial (e.g., left/right location) and featural (e.g., color)—in different object tasks. In Experiment 1, we tested whether infants and preschoolers extract both the spatial and featural properties of objects, and, importantly, how these cues are weighted when pitted against each other. We found that infants relied primarily on spatial cues and neglected featural cues. By contrast, preschoolers showed the opposite pattern of weighting, placing greater weight on featural information. In Experiment 2, we tested the hypothesis that the developmental shift from spatial to featural weighting reflects a shift from a priority on object individuation (how many objects) in infancy to object classification (what are the objects) at preschool age. Here, we found that preschoolers weighted spatial information more than features when the task required individuating objects without identifying them, consistent with a specific role for spatial information in object individuation. We discuss the relevance of spatial-featural weighting in relation to developmental changes in children’s object representations.

Spatial attention in encoding letter combinations

Reading requires the correct identification of letters and letter positions within words. Selective attention is, therefore, required to select chunks of the text for sequential processing. Despite the extensive literature on visual attention, the well-known effects of spatial cues in simple perceptual tasks cannot inform us about the role of attention in a task as complex as reading. Here, we systematically manipulate spatial attention in a multi-letter processing task to understand the effects of spatial cues on letter encoding in typical adults. Overall, endogenous (voluntary) cue benefits were larger than exogenous (reflexive). We show that cue benefits are greater in the left than in the right visual field and larger for the most crowded letter positions. Endogenous valid cues reduced errors due to confusing letter positions more than misidentifications, specifically for the most crowded letter positions. Therefore, shifting endogenous attention along a line of text is likely an important mechanism to alleviate the effects of crowding on encoding letters within words. Our results help set the premise for constructing theories about how specific mechanisms of attention support reading development in children. Understanding the link between reading development and attention mechanisms has far-reaching implications for effectively addressing the needs of children with reading disabilities.

Technology-Aided Spatial Cues, Instructions, and Preferred Stimulation for Supporting People With Intellectual and Visual Disabilities in Their Occupational Engagement and Mobility: Usability Study

Background Persons with severe or profound intellectual disability and visual impairment tend to be passive and sedentary, and technology-aided intervention may be required to improve their condition without excessive demands on staff time. Objective This study aims to extend the assessment of technology-aided interventions for supporting functional occupational engagement and mobility in 7 people with intellectual disability and visual impairment and to use a technology system that is simpler and less expensive than those previously used. Methods The technology system involved a Samsung Galaxy A10, 4 Philips Hue indoor motion sensors, and 4 mini speakers. Within each session, the participants were to collect 18 objects (ie, one at a time) from 3 different areas (stations) located within a large room, bring each of the objects to a central desk, and put away each of those objects there. For each object, the participants received verbal (spatial) cues for guiding them to the area where the object was to be collected, a verbal instruction (ie, request) to take an object, verbal (spatial) cues for guiding them to the central desk, a verbal instruction to put away the object collected, and praise and preferred stimulation. Results During baseline, the frequency of responses completed correctly (objects collected and put away independently) was 0 or near 0. During the intervention phase (ie, with the support of the technology setup), the frequency increased for all participants, reaching a mean of almost 18 (out of 18 response opportunities) for 6 participants and about 13 for the remaining participant. The mean session duration ranged from 12 to 30 minutes. Conclusions A program, such as the one used in this study, can be useful in promoting occupational engagement and mobility in persons with intellectual disability and visual impairment.

Ambisonics Sound Source Localization With Varying Amount of Visual Information in Virtual Reality

To reproduce realistic audio-visual scenarios in the laboratory, Ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, Ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st-, 3rd-, 5th- or 11th-order Ambisonics with and without visual information. Results showed that with 1st-order Ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small. The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the Ambisonics order, there was no interaction between the Ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using Ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of the auditory stimuli.

Recurrent rewiring of the adult hippocampal mossy fiber system by a single transcriptional regulator, Id2

Circuit formation in the central nervous system has been historically studied during development, after which cell-autonomous and nonautonomous wiring factors inactivate. In principle, balanced reactivation of such factors could enable further wiring in adults, but their relative contributions may be circuit dependent and are largely unknown. Here, we investigated hippocampal mossy fiber sprouting to gain insight into wiring mechanisms in mature circuits. We found that sole ectopic expression of Id2 in granule cells is capable of driving mossy fiber sprouting in healthy adult mouse and rat. Mice with the new mossy fiber circuit solved spatial problems equally well as controls but appeared to rely on local rather than global spatial cues. Our results demonstrate reprogrammed connectivity in mature neurons by one defined factor and an assembly of a new synaptic circuit in adult brain.