Spatial Imagery Research Articles

The Imagery Vividness and Preferences of Older People: Implications for Visualization in Concept Design

ABSTRACTWithin the user-centred design method, the effectiveness of the visual representation of concepts approach in eliciting user experiences and thoughts about products, systems and interfaces depends on the visualization skills of the user. However, the ability to visualize relies on the cognitive functions of the user, which are known to decline over the course of a lifetime. The study reported in this paper was aimed at exploring whether older people might encounter difficulties or fail to participate in concept design visualization. Vividness of visual imagery (VVI), object imagery preference (OI) and spatial imagery preference (SI) instruments were administered on thirty-one older participants. VVI was found to be the best predictor of participants' ease of visualization in concept design, followed by OI and then SI. The findings provide useful information for designers and facilitators when involving older people in the user-centred design method. It is recommended that a precursor assessment of the vividness with which older participants visualize images be conducted before the user-centred design process begins.

Interference in Visual Perception by Verbal and Spatial Cognitive Activity

In two experiments we tested the hypothesis that cognitive processing based on spatial imagery produces more deterioration of visual perception than cognitive processing based on verbal codes. So, we studied the effect on visual perception of two cognitive tasks, one of spatial imagery and the other a verbal task. In the first one, with 30 participants, we analyzed the mental load and ocular behaviors in both cognitive tasks. In the second experiment, with 29 participants, we studied the effect of both tasks on a visual search task, using a dual-task experimental paradigm. The verbal task presented higher mental load than the imagery task when both tasks were carried out with visual search task, and there was more deterioration in stimulus detection with the verbal task. We can conclude that: (1) cognitive tasks produce important deterioration in the capacities of visual search and identification of stimuli; (2) this deterioration has two components: (a) an inefficient search, associated with alterations of the gaze patterns while performing cognitive tasks, and (b) a general interference, nonspecific to spatial codes, in the process of identification of looked-at stimuli; (3) this cognitive interference is related to the mental load or effort required by the cognitive task.

An IKONOS-based comparison of methods to estimate cattle home ranges in a semi-arid landscape of southern Africa

We estimated home range (HR) and core areas of cattle herds in a semi-arid rangeland in southern Africa using the fixed kernel and the local convex hull (LoCoH) methods. We also compared the HR values of the two methods with the aid of high spatial resolution IKONOS imagery. We also compared area estimates determined by the two methods at different probability contours of the utilization distribution (UD). Results showed that the LoCoH performed better than the kernel method in estimating UD. We found significant (p < 0.05) differences concerning the area estimated at each probability contour of the UD between the fixed kernel and LoCoH methods. However, both methods produced similar land cover preferences within the HR and core areas. Based on IKONOS-imagery-aided evaluation, our results imply that LoCoH determines core areas in HR analysis better than the kernel method, while both methods can be used in preference analysis.

Probing for consciousness after severe brain injury by functional magnetic resonance imaging (fMRI)

Persistent states of reduced consciousness such as the vegetative and the minimally consciousness state (MCS) may be the result of severe traumatic brain injury (TBI). In these conditions, the level of consciousness is challenging to diagnose correctly, and diagnostic error rates are high [1]. Recently, there has been major progress in the study of disorders of consciousness [2–4], and today there exist valid functional magnetic resonance imaging (fMRI) protocols to probe for willful cognitive processing [5]. These protocols are based on verbal instructions to imagine a motor task and a spatial navigation task that activate the supplementary motor area (SMA) and the parahippocampal gyrus (PG), respectively [5]. If a patient displays bloodoxygenation-level-dependent (BOLD) responses similar to the activation seen in healthy controls, it can be assumed that conscious cognitive processing is present. Conversely, negative neurophysiological findings are not evidence for lack of consciousness, because false-negative results are common even in healthy controls [3]. Here we describe the case of a 20-year-old woman who sustained TBI after a traffic accident. At arrival at the hospital, her Glasgow Coma Scale score was 3. Computed tomography (CT) revealed diffuse edema and intracranial hematoma over the left hemisphere that was immediately evacuated. Twelve months post ictus, she was not able to produce verbal or motor responses and was diagnosed to be in MCS. During this time, she had been repeatedly tested with the Coma Recovery Scale–Revised (CRS-R) [6]; minimum score was 5 (2 months post ictus) and maximum 11 at the time of scanning, mainly based on visual functioning. Furthermore, it was occasionally observed that she showed facial emotional responses, and that she produced laughter-like sounds when hearing jokes. Therefore, we measured the patient’s brain responses for receptive language processing and voluntary mental activity using fMRI. Receptive language processing was assessed by a passive-listening task [7]. Two imagery tasks were verbally presented in the scanner: to imagine walking through her home, and to imagine playing tennis, with similar fMRI parameters as in Owen and colleges [3]. Eight healthy females (age 20–22 years) were tested on the same tasks and served as controls. The fMRI examination revealed that she displayed cortical responses similar to the control group on the language task and on the tennis task, but she did not display similar activation as healthy controls in the PG during the navigation task (Fig. 1). The latter might be due to lesions in her PG (confirmed by structural MRI), an area that is important for spatial imagery processing [8]. The similarity in the activation between the patient and the controls indicates that the patient cooperated with the instructions during the scan. This suggests that she P. M. Aslaksen and T. R. Vangberg contributed equally to this work.

Time–space radiometric normalization of TM/ETM+ images for land cover change detection

A novel approach to image radiometric normalization for change detection is presented. The approach referred to as stratified relative radiometric normalization (SRRN) uses a time-series of imagery to stratify the landscape for localized radiometric normalization. The goal is to improve the detection accuracy of abrupt land cover changes (human-induced, natural disaster, etc.) while decreasing false detection of natural vegetation changes that are not of interest. These vegetation changes may be associated with such phenomena as phenology, growth and stress (e.g. drought), which occur at varying spatial and temporal scales, depending on landscape position, vegetation type, season, precipitation history and historic episodes of local disturbance. The SRRN approach was tested for a study area on the Californian border between the USA and Mexico using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus satellite imagery. Change products were generated from imagery radiometrically normalized using the SRRN procedure and with imagery normalized using a traditional empirical line technique. Reference data derived from high spatial resolution airborne imagery were utilized to validate the two change products. The SRRN procedure provided several benefits and was found to improve the overall accuracy of detecting abrupt land cover changes by nearly 20%.

Use of MODIS NDVI data to improve forest-area estimation

The objective of this article is to develop and test a methodology capable of using medium spatial resolution satellite imagery to improve forest-area statistics derived from ground sampling. The methodology builds on the evidence that multitemporal Normalized Difference Vegetation Index (NDVI) images bring significant information on the spatial distribution of forest surfaces. Consequently, Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI images are potentially useful to improve forest-area assessment based on ground data. This expectation is verified in Tuscany (central Italy) using forest-area references extracted from the Coordination of Information on Environment (CORINE) land-cover map. The accuracy of forest-area statistics obtained at province level by different reference samplings is first assessed. Next, locally calibrated regression analyses are applied to multitemporal MODIS NDVI images in order to obtain per-pixel forest-area estimates. Two statistical methods (the direct expansion and the regression estimator) are finally used to combine these estimates with the ground data and produce corrected per-province statistics. The experimental results confirm that MODIS NDVI data contain relevant information on forest distribution, which can be efficiently extended over the land surface by locally calibrated regressions. The obtained estimates can be combined with the ground data for enhancing forest-area assessment at province level. To this aim, the regression estimator gives the best performance for all sampling densities of the reference data.

The effects of user factors and symbol referents on public symbol design using the stereotype production method

This study investigated the influence of user factors and symbol referents on public symbol design among older people, using the stereotype production method for collecting user ideas during the symbol design process. Thirty-one older adults were asked to draw images based on 28 public symbol referents and to indicate their familiarity with and ease with which they visualised each referent. Differences were found between the pictorial solutions generated by males and females. However, symbol design was not influenced by participants’ education level, vividness of visual imagery, object imagery preference or spatial imagery preference. Both familiar and unfamiliar referents were illustrated pictorially without much difficulty by users. The more visual the referent, the less difficulty the users had in illustrating it. The findings of this study should aid the optimisation of the stereotype production method for user-involved symbol design.

Factor Structure of the Spanish Version of the Object-Spatial Imagery and Verbal Questionnaire

The reliability and factor structure of the Spanish version of the Object-Spatial Imagery and Verbal Questionnaire (OSIVQ) were assessed in a sample of 213 Spanish university graduates. The questionnaire measures three types of processing preferences (verbal, object imagery, and spatial imagery). Principal components analysis with varimax rotation identified three factors, corresponding to the three scales proposed in the original version, explaining 33.1% of the overall variance. Cronbach's alphas were .72, .77, and .81 for the verbal, object imagery, and spatial imagery scales, respectively.

Detection and classification of invasive saltcedar through high spatial resolution airborne hyperspectral imagery

We evaluated the performance of airborne HyperSpecTIR (HST) images for detecting and classifying the invasive riparian vegetation saltcedar along the Muddy River in Clark County, Nevada. HyperSpecTIR image reflectance spectra (227 bands, 450–2450 nm) were acquired for the following four vegetation covers: invasive saltcedar, native honey mesquite, grassland patches and crops. We compared five feature reduction approaches: band selection based on Jeffreys–Matusita distance, principal component analysis (PCA), minimum noise fraction (MNF), segmented principal component transform (SPCT) and segmented minimum noise fraction (SMNF). In addition, maximum likelihood (ML) and two spectral angle mapper (SAM) classifiers were applied to all extracted bands or features. Classification accuracies were compared among all classification approaches. Although the overall accuracy of maximal likelihood classifiers generally surpassed that of SAM classifiers, the highest overall accuracy was achieved by a SMNF-SAM combination with adjusted angular thresholds for classes. We concluded that high spectral and spatial resolution imagery can be used to detect and classify invasive saltcedar in this arid area.

Mental transformation abilities in patients with unilateral and bilateral vestibular loss

Vestibular information helps to establish a reliable gravitational frame of reference and contributes to the adequate perception of the location of one's own body in space. This information is likely to be required in spatial cognitive tasks. Indeed, previous studies suggest that the processing of vestibular information is involved in mental transformation tasks in healthy participants. In this study, we investigate whether patients with bilateral or unilateral vestibular loss show impaired ability to mentally transform images of bodies and body parts compared to a healthy, age-matched control group. An egocentric and an object-based mental transformation task were used. Moreover, spatial perception was assessed using a computerized version of the subjective visual vertical and the rod and frame test. Participants with bilateral vestibular loss showed impaired performance in mental transformation, especially in egocentric mental transformation, compared to participants with unilateral vestibular lesions and the control group. Performance of participants with unilateral vestibular lesions and the control group are comparable, and no differences were found between right- and left-sided labyrinthectomized patients. A control task showed no differences between the three groups. The findings from this study substantiate that central vestibular processes are involved in imagined spatial body transformations; but interestingly, only participants with bilateral vestibular loss are affected, whereas unilateral vestibular loss does not lead to a decline in spatial imagery.

'Great Chords': Politics and Romance in Tolstoy's War and Peace

A national epic and Bildungsroman , Tolstoy's realist masterpiece also incorporates a quest romance, which flirts with fantasy by allusions to volshebnoye tsarstvo ('fairyland'). This romance projects a social ideal that reflects Tolstoy's thorough-going alienation from modernity. The article uses Northrop Frye's ideas to disclose the hidden romance and reveals its political significance by comparing Tolstoy's story to Walter Scott's Waverley and J.R.R. Tolkien's The Lord of the Rings . Politics and romance are strange bedfellows, but each lends itself to spatial representation. The article shows how Tolstoy uses spatial imagery to infuse his quest romance with political meaning and discusses the neglect by English-speaking critics of romance and politics alike, which it relates to a disagreement between Percy Lubbock and E.M. Forster over the relative importance of time and space as dimensions of Tolstoy's narrative.

Spatial imagery of novel places based on visual scene transformation

The hippocampus is known to maintain memories of object-place associations that can produce a scene expectation at a novel viewpoint. To implement such capabilities, the memorized distances and directions of an object from the viewer at a fixed location should be integrated with the imaginary displacement to the new viewpoint. However, neural dynamics of such scene expectation at the novel viewpoint have not been discussed. In this study, we propose a method of coding novel places based on visual scene transformation as a component of the object-place memory in the hippocampus. In this coding, a novel place is represented by a transformed version of a viewer’s scene with imaginary displacement. When the places of individual objects are stored with the coding in the hippocampus, the object’s displacement at the imaginary viewpoint can be evaluated through the comparison of a transformed viewer’s scene with the stored scene. Results of computer experiments demonstrated that the coding successfully produced scene expectation of a three object arrangement at a novel viewpoint. Such the scene expectation was retained even without similarities between the imaginary scene and the real scene at the location, where the imaginary scenes only functioned as indices to denote the topographical relationship between object locations. The results suggest that the hippocampus uses the place coding based on scene transformation and implements the spatial imagery of object-place associations from the novel viewpoint.

The Language of Numerical Data and Figures in Internal Company Communications

AbstractThis paper looks at the language used to talk about numerical data and figures as part of in-house, computer-mediated audio-conferencing between managers and their staff in corporate settings. The data consist of a sub-corpus of oral presentations taken from a much larger self-compiled multi-document corpus of business communications. The research is aimed at describing the predominant pragma-linguistic features of these accounts of graphical and numerical data, the most appropriate and effective means of identifying and tracing these, together with the ways participants subjectivize their information and create relevance for their interlocutors, in this specific multi-medial, multi-modal business context. The features focused on include temporal and locational deixis, visual and spatial imagery and the use of time and tense. Findings show that these discourse creation processes play a significant part in the multi-functional character of the presentations, in enacting evaluation, persuasion and the construal of corporate-professional roles and identities. They also reveal something about the nature of virtual professional, communicative space, and the socially-situated creation of corporate-managerial discourse.

Describing coral reef bleaching using very high spatial resolution satellite imagery: experimental methodology

This paper proposes an experimental methodology toward describing and quantifying coral reef bleaching using very high spatial resolution optical satellite imagery. Sea surface temperature-based bleaching alerts issued by NOAA's Coral Reef Watch triggered image acquisition and served as an indication for high bleaching probability. Images of suspected coral reef bleaching events and reference images of the same reefs during previous unbleached conditions were coregistered and radiometrically normalized for change detection. An experimental methodology was developed to describe the severity and extent of the bleaching. The methodology hinges on the creation of the Coral Bleaching Index (CBI), constructed from change detected in the green, blue, and red wavelength bands. Results are provided in the form of colorized difference images showing areas of observed bleaching in gold, as well as CBI images, visualizing varying bleaching intensities. Comparison of the CBI with available field validation data yielded a correlation, however additional reference data would be needed for more detailed quality assessment. This technique is seen as a step toward the routine detection and long-term monitoring of coral reef bleaching from space and serves as a proposed tool for detecting bleaching in remote areas where observers cannot be deployed.

‘Great Chords’: Politics and Romance in Tolstoy's War and Peace

A national epic and Bildungsroman, Tolstoy's realist masterpiece also incorporates a quest romance, which flirts with fantasy by allusions to volshebnoye tsarstvo (‘fairyland’). This romance projects a social ideal that reflects Tolstoy's thoroughgoing alienation from modernity. The article uses Northrop Frye's ideas to disclose the hidden romance and reveals its political significance by comparing Tolstoy's story to Walter Scott's Waverley and J.R.R. Tolkien's The Lord of the Rings. Politics and romance are strange bedfellows, but each lends itself to spatial representation. The article shows how Tolstoy uses spatial imagery to infuse his quest romance with political meaning and discusses the neglect by English-speaking critics of romance and politics alike, which it relates to a disagreement between Percy Lubbock and E.M. Forster over the relative importance of time and space as dimensions of Tolstoy's narrative.

Object–spatial imagery and verbal cognitive styles in children and adolescents: Developmental trajectories in relation to ability

A new self-report instrument, the Children's Object–Spatial Imagery and Verbal Questionnaire (C-OSIVQ), was designed to assess cognitive styles in younger populations (8–17 years old). The questionnaire was based on the previously developed adult version of the Object–Spatial Imagery and Verbal Questionnaire (OSIVQ; Blazhenkova & Kozhevnikov, 2009), and includes three scales assessing object, spatial, and verbal cognitive styles. The C-OSIVQ was validated on a large sample consisting of 267 children and 83 college students. It demonstrated high internal reliability, predictive, and ecological validity in both children and adults. Following the design and validation of the C-OSIVQ, the development of object, spatial, and verbal cognitive styles and their corresponding abilities was examined across a wide range of ages (8–60 years old). The development of styles and abilities were strongly correlated across age groups, indicating that the trajectory of cognitive style development closely resembles the developmental trajectory of abilities; however, the development of cognitive style is more gradual and smooth.

Spatial refinement of census population distribution using remotely sensed estimates of impervious surfaces in Haiti

Previous research on the relationship between impervious surfaces and population has focused on limited areas. This paper considers the relationship for an entire country. Multiple spatial resolution optical imagery was integrated with census data to refine the spatial distribution of population in Haiti. A classification and regression tree (CART) methodology was used to create a percent impervious-area layer based on ten high-resolution training chips and a Landsat Enhanced Thematic Mapper (ETM+) mosaic. This estimate then became an input for a dasymetric mapping approach, where population was distributed proportionately to impervious areas with input from ancillary data sources. Haiti's section boundaries (third administrative level) provided the mapping base because a strong relationship between imperviousness and population was observed at this administrative level. The accuracy of the technique was tested for a set of 110 municipalities in Haiti, making use of recent census data. The potential usefulness of imagery-based population estimates for areas where census data do not exist was also tested by dividing Haiti into northern and southern portions and using one to predict the other.

Spatial Perception and Cognition in Multichannel Audio for Electroacoustic Music

Listeners experience electroacoustic music as full of significance and meaning, and they experience spatiality as one of the factors contributing to its meaningfulness. If we want to understand spatiality in electroacoustic music, we must understand how the listener’s mental processes give rise to the experience of meaning. In electroacoustic music as in everyday life, these mental processes unite the peripheral auditory system with human spatial cognition. In the discussion that follows we consider a range of the listener’s mental processes relating space and meaning from the perceptual attributes of spatial imagery to the spatial reference frames for places and navigation. When considering multichannel loudspeaker systems in particular, an important part of the discussion is focused on the distinctive and idiomatic ways in which this particular mode of sound production contributes to and situates meaning. These include the phenomenon of image dispersion, the important consequences of the precedence effect and the influence of source characteristics on spatial imagery. These are discussed in close relation to the practicalities of artistic practice and to the potential for artistic meaning experienced by the listener.

Estimates of bark beetle infestation expansion factors with adaptive cluster sampling

Insects have infested over 37 million hectares of forested land, the most aggressive forest insect pest in North America is the mountain pine beetle that has attacked 14 million hectares. To determine infestation extent and spread rates, we examined mountain pine beetle damage at two sites over two consecutive years (2007–2008). High spatial resolution (20 cm) airborne digital imagery was acquired over a range of infestation intensities (High: site A; Low: site B). An adaptive cluster sampling approach assessed the extent and severity of damage from the imagery. In 2007, site A contained 5.22 infested trees per hectare (variance: 10.65) increasing in 2008 to 11.02 trees per hectare (variance: 24.83). In contrast, site B had 0.25 infested trees per hectare in 2007 (variance: 0.02), which increased in 2008 to 0.47 trees per hectare, with a variance of 0.08 trees per hectare. At both sites, infestations approximately doubled over a 1-year period. Adaptive cluster sampling applied to high spatial resolution airborne imagery can provide estimates of the severity of attack on the landscape.

A Cinematic Spatial Sound Display for Panorama Video Applications

This paper describes a new sound spatialisation system which is an integral part of Rensselaer Polytechnic Institute’s new Experimental Media and Performing Arts Center (EMPAC). The Cinematic Spatial Sound Display (CSSD) was originally conceived for interactive panorama video installations, but the architecture goes beyond this particular application. The CSSD is characterised by its scalability to various loudspeaker configurations. It spatialises sound from dry sound files or live sources using control data that describe the spatial scenes. The time lines for source positions and other experimental parameters can be stored and edited in the CSSD, and the system can also process live user input to control selected parameters. The CSSD is more than just a sound positioning tool, and the underlying Virtual Microphone Control (ViMiC) technology was developed to support artists in designing new forms of spatial imagery. The software enables the user to create computer-generated rooms with virtual microphones and sound sources. The algorithm uses physical laws to auralise acoustic scenes – allowing realistic effects such as the Doppler shift and the simulation of various classical microphone techniques. Various parameters of ViMiC can be adjusted in real time, including the directivity patterns and orientations of both the microphones and sound sources as well as their precise locations. Surreal scenes can be created by assigning artificial directivity patterns to microphones or changing the laws of physics in the model. An algorithm to extract the sound-source positions in recordings using a microphone array is also part of the CSSD. The algorithm was specifically designed to operate in multiple sound-source scenarios and can also be used for telematic music applications.