Head-mounted Video Camera Research Articles

Head-mounted cameras and stimulated recall in qualitative sport research

There are a number of innovative procedures available for use in qualitative research, including observation, note-taking and verbal protocol techniques. This paper highlights the potential usefulness of stimulated recall as an innovative technique for use in qualitative research in sport and possibly exercise. Specifically, it focuses on video footage obtained from head-mounted cameras for use in stimulated recall during post-event interviews. Examples of research studies carried out in simulation training with fire and emergency personnel and with leisure participants in a whitewater adventure setting, are used to illustrate how stimulated recall can be utilised effectively in practice. Participants in a river-surfing course completed daily qualitative semi-structured interviews, facilitated by footage from head-mounted video cameras. The cameras were worn throughout the course while participants were in the water. The use of the head-mounted equipment and video-footage as stimulated recall in the study and preliminary findings about the procedure are described. Finally, a number of advantages and disadvantages of head-mounted camera and stimulated recall procedures in general are discussed.

Expanding the Flow Model in Adventure Activities: A Reversal Theory Perspective

This study integrated flow theory and reversal theory perspectives to investigate a potential range of flow states amongst adventure participants in a sequence of two studies. Study one was conducted with expert (n = 6) adventure participants via retrospective interviews, while study two collected prospective data from novice whitewater riversurfers (n = 10) via waterproof-surveys and head-mounted video cameras. These methods were used to evaluate previous conjectures that distinct ‘serious’ (telic) and ‘playful’ (paratelic) flow states may occur in adventure activities and to identify key characteristics which may underpin distinct flow states. Results highlighted qualitative differences amongst flow states, as well as suggesting that flow research in adventurous pursuits could benefit from the integration of reversal theory constructs.

What makes an orienteer an expert? A case study of a highly elite orienteer's concerns in the course of competition

This article reports a highly elite orienteer's cognitive activity over the course of two international competitions. We characterize the orienteer's concerns in relation to the problems raised during the competitions. The participant wore a head-mounted video camera throughout the competitions to enable the capture of an events record from the participant's perspective. During a post-performance self-confrontation interview, the participant was played the video and asked to describe his activity in relation to the events observed. The interview data were then used to identify the orienteer's concerns at each instant during the races. These “local” concerns were then compared and subsequently classified to characterize the typical concerns of the participant. Results showed three typical concerns: (a) find the controls faster than the opponents; (b) optimize running pace throughout the race; and (c) reflect on actions undertaken during performance. Results suggest the performer used a range of knowledge-driven strategies that enhanced the efficiency of task performance, and flexibly switched between strategies and decision-options in the face of presented changes in the task status. He also engaged in various reflective processes concurrent with performance that augmented the use of these strategies. In conclusion, this study provides insight into the cognitive processes underlying expert performance in sports characterized by decision-making under complexity, uncertainty, and time pressure.

Separate mechanisms for long- and short-term contrast adaptation

Depriving the adult visual system of contrast at an orientation increases sensitivity to that orientation. Such contrast adaptation strengthens as the inducing period lengthens, with long periods producing longer-lasting effects. This could occur because over time, either a single mechanism gains strength, or additional long-term mechanisms become active. We tested between these alternatives by measuring effects of short-term adaptation before and after long-term adaptation. Subjects were deprived of vertical energy for 4 hours, viewing the world through an “altered reality” system comprised of a head mounted video camera, a computer, and a head-mounted display. Vertical energy was filtered from the video, allowing subjects to interact with the world while being deprived of an orientation. Following this long-term adaptation, which prior work has shown generates large adaptation effects, subjects “deadapted” over the short-term by viewing unfiltered images for 15 min. Subjects then “readapted”, viewing filtered images for 8 min. We measured effects of adaptation using the tilt aftereffect. An initial control period of adaptation, lasting 8 min, showed a weak tilt aftereffect of ~2 deg, lasting 100 sec. Following the four hours of adaptation and 15 min of deadaptation, subjects showed no tilt aftereffect. However, the subsequent 8 min adaptation period generated a large, 3 deg aftereffect, that lasted over 5 min. Together, these results are inconsistent with a single mechanism controlling adaptation, because identical short-term adaptation periods generated different effects depending upon long-term adaptation history. The simplest account of our results is that 4 hours of adaptation produced effects in both short- and long-term mechanisms. Short-term deadaptation then produced a negative effect that masked ongoing long-term adaptation. The 8-min readaptation reestablished the short-term effect and unmasked the long-term effect. Thus, deadaptation and readaptation affected short-term adaptation independent of long-term adaptation, demonstrating that different time-scales are controlled by separate mechanisms.

Gaining Insights to the Clinical Reasoning that Supports an on-Road Driver Assessment

Researchers have yet to examine the clinical reasoning of occupational therapists undertaking driver assessments. Conduct pilot research exploring the kinds of clinical reasoning used during an on-road driver assessment and to determine if the quality of the data supports further inquiry into the use of head-mounted video camera footage to prompt recall of clinical reasoning. Using a single-case, qualitative design, head-mounted video camera was used to record the on-road assessment and the therapist subsequently provided her reasoning using video-prompted recall. The video footage from the head-mounted camera provided an excellent prompt, and the therapist was able to give a thorough account of her clinical reasoning during the on-road assessment. Implications. This novel method of capturing on-road driver assessments and prompting recall of reasoning has the potential to aid expert and novice driver assessors understand and advance the clinical reasoning that guides fitness-to-drive recommendations.

Effects of Orientation-Specific Visual Deprivation Induced with Altered Reality

What happens to neurons in visual cortex when they are deprived of their preferred stimuli? Long-term deprivation during development, spanning weeks, reduces the number of neurons selective for the deprived orientation [1-4]. In contrast, short-term deprivation in adults, for periods of seconds, can increase neural sensitivity relative to a stimulated baseline [5]. Effects over intermediate timescales remain largely unexplored, however. Here we introduce a new method for manipulating the visual environment of adult humans and report effects of four hours of orientation-specific deprivation. Subjects wore a head-mounted video camera that fed into a laptop computer that drove a head-mounted display. Software filtered the video stream in real time, allowing subjects to interact with the world while being deprived of visual input at a specified orientation. Four hours in this environment increased sensitivity to the deprived orientation, which likely reflected an increase in responsiveness of neurons in early visual cortex. Our results help distinguish between two theories of neural adaptation: the response increase optimized the responses of individual neurons, rather than increasing the efficiency of the population code. Our method should be able to produce a wide range of environmental manipulations useful for studying many topics in perception.

Relationship between Static Ocular Counterroll and Bielschowsky Head Tilt Phenomenon

This study was conducted to assess how hyperdeviation of a paretic eye during ipsilesional head tilt-the Bielschowsky head tilt phenomenon (BHP)-can be explained by decreased compensatory ocular counterrolling (OCR) due to the depressed torque of the paretic superior oblique (SO) muscle. Thirty-three patients with clinically diagnosed SO palsy and 11 control subjects were studied. With a head-mounted video camera, static ocular counterrolling (s-OCR) was determined by measuring the inclination of a line connecting the two centroids of the characteristic iris pattern and corneal reflex. The BHP was measured with the alternate prism and cover test. The mean (SD) amplitude of s-OCR in paretic eyes based on the fit of the regression sine curve against the ipsilesional head tilt angle was significantly decreased compared with that for contralesional head tilt, 6.3 (3.5) degrees for ipsilesional and 11.3 (3.9) degrees for contralesional (P < 0.001), and was significantly smaller than that in normal subjects: 10.9 (2.6) degrees (P < 0.001). No significant linear relation was noted between hyperdeviation on ipsilesional head tilt and the amplitude of s-OCR in paretic eyes (r(2) = 0.04; P = 0.29). However, the differences between the hyperdeviation with ipsilesional 30 degrees head tilt and with head-upright position correlated significantly with the amplitudes of s-OCR in paretic eyes (r(2) = 0.19, P = 0.01). The absolute value of the hypertropia on ipsilesional head tilt in clinically diagnosed SO palsy does not directly assess the function of the SO muscle. The difference in hypertropia between ipsilesional head tilt and the upright position, however, may be a better indicator of SO function.

Feasibility Study of a Retinal Prosthesis

To demonstrate that an epiretinal prosthesis can produce patterned visual perception in patients blinded by photoreceptor degeneration who have no other treatment options. A totally blind subject with retinitis pigmentosa had a 16-electrode epiretinal prosthesis implanted. The implant is controlled wirelessly by an external computer or a head-mounted video camera. Spatial vision was assessed by measuring the subject's response to direct stimulation of patterns and by comparing the ability of the subject to identify the orientation of gratings with the system on and off. In response to stimulation of 2 orthogonal rows of electrodes, the subject drew 2 lines with a mean (SEM) angle of 87.4 degrees (1.8 degrees) between them. With the system on, the subject identified the orientation of the grating target up to a spatial resolution that matches the spacing between the adjacent electrodes. In contrast, with the system off, the subject could not detect or identify the target's orientation. Synchronized stimulation of different retinal locations with an epiretinal prosthesis implanted long-term can produce spatial vision with an acuity level determined by the distance between the electrodes. clinicaltrials.gov Identifier: NCT00279500.

Using a Head-Mounted Video Camera to Understand Social Worlds and Experiences

1.1 This paper considers the use of digital video as a research method for qualitative researchers; specifically the head-mounted video (headcam) and the opportunities it offers for deepening our understanding of social life. Headcam is one of a range of recent technological innovations relating to video that provide researchers with new means of addressing methodological challenges. To date, little has been written about the use of digital video in relation to social research (Henley 1998; Pink 2007a). Even less has been written on the specifics of headcam video techniques and less still on its potential outwith a positivist framework. Our exploratory research on mountain bikers' and walkers' embodied, multi-sensory ways of knowing and experiencing landscapes demonstrates some of the possibilities that advancements in headcam technology can offer interpretative and reflexive approaches to social research.

Applications of augmented‐vision head‐mounted systems in vision rehabilitation

Vision loss typically affects either the wide peripheral vision (important for mobility), or central vision (important for seeing details). Traditional optical visual aids usually recover the lost visual function, but at a high cost for the remaining visual function. We have developed a novel concept of vision-multiplexing using augmented vision head-mounted display systems to address vision loss. Two applications are discussed in this paper. In the first, minified edge images from a head-mounted video camera are presented on a see-through display providing visual field expansion for people with peripheral vision loss, while still enabling the full resolution of the residual central vision to be maintained. The concept has been applied in daytime and nighttime devices. A series of studies suggested that the system could help with visual search, obstacle avoidance, and nighttime mobility. Subjects were positive in their ratings of device cosmetics and ergonomics. The second application is for people with central vision loss. Using an on-axis aligned camera and display system, central visibility is enhanced with 1:1 scale edge images, while still enabling the wide field of the unimpaired peripheral vision to be maintained. The registration error of the system was found to be low in laboratory testing.

Visual attention in orienteers at different levels of experience

This study explored how differences in orienteering experience are related to differences in how visual attention is allocated to the map, the environment and to travel. Twenty more experienced and 20 less experienced individuals orienteered while wearing a head-mounted video camera with microphone. The participants verbalized what they were attending to (map, environment or travel) at any given time. Each recorded film was coded at each point in time in terms of what the participant was attending to and whether the participant was moving or stationary. More experienced orienteers attended to the map markedly more while moving and spent less time stationary than less experienced orienteers. The participants' performance was significantly related to the ability to attend to the map while moving. The strategic control of attention is proposed to explain this ability. It is proposed that attentional training might enhance performance in sports characterized by multiple and dynamically varying elements.

Clinical Reasoning during Community Health Home Visits: Expert and Novice Differences

Very little is known about the differences between novice and expert clinical reasoning in community health practice. This article presents the findings of a study of the clinical reasoning of five expert and five novice community health occupational therapists (CHOTs) during the conducting of home visits. A head-mounted video camera was used to record the visits, followed by the participants reporting their clinical reasoning verbally using a video-assisted debriefing method. The transcripts from these verbal reports were analysed quantitatively and qualitatively. The quantitative results demonstrated many differences between experts and novices in terms of the amounts and types of clinical reasoning used. For example, the novices used more procedural reasoning whereas the experts used more conditional reasoning and mixes of different reasoning types. The qualitative results demonstrated that the experts used a free-flowing conversational approach when reasoning during home visits whereas the novices depended on external structures such as assessment forms to guide the process. Given their experience and familiarity with the process, the experts were confident and clear in their reasoning whereas the novices were more awkward and self-conscious. The experts handled sensitive issues whereas the novices seemed to avoid them. The study findings may provide insights for student and novice therapists concerning expert CHOTs' practice and promote reflection in general on the attainment of expertise in clinical practice.

Using a Head-Mounted Video Camera To Explore Current Conceptualizations of Clinical Reasoning in Occupational Therapy

The purpose of this study was to explore current conceptualizations of clinical reasoning in occupational therapy. Using a head-mounted video camera and debriefing interviews following therapy sessions, clinical reasoning data were collected from 13 experienced occupational therapists working in physical rehabilitation. The data were collected and analyzed within a focused ethnographic framework. Mattingly and Fleming's (1994) classification of clinical reasoning encompassed most of the thinking processes revealed in the therapists' debriefing interviews. Therapists also used aspects of pragmatic reasoning (Schell & Cervero, 1993). Additionally, within the forms of procedural, interactive, conditional, and pragmatic reasoning, a new form of "generalization reasoning" is proposed in which therapists draw on past experience or knowledge to assist them in making sense of a current situation or client circumstance. This research builds upon previous classification systems to support the categories of narrative, procedural, interactive, conditional, pragmatic (practice context), and generalization reasoning to explain how occupational therapists think in action. Further research is required to explore this emerging description of clinical reasoning.

Clinical Reasoning: How do Pragmatic Reasoning, Worldview and Client-Centredness Fit?

Using both clinical reasoning data and literature from the past 20 years, this paper sought to examine the relationship between client-centred practice and clinical reasoning, to explore the concept of pragmatic reasoning and to present a diagrammatic conceptualisation of our knowledge of clinical reasoning in occupational therapy. The clinical reasoning literature published between 1982 and 2001 was reviewed and this information was combined with the findings from a study which used a head-mounted video camera to collect data and then explore the clinical reasoning of 13 experienced occupational therapists. The data were collected and analysed within a focused ethnographic framework. The findings showed that clinical reasoning occurred in the context of client-centred practice, but that a reciprocal relationship appeared to exist between client-centred practice and interactive reasoning. It also appeared that pragmatic reasoning was related only to the therapist's practice context and that all forms of reasoning were influenced by the therapist's worldview. A diagram was developed to depict this current understanding of the modes of clinical reasoning. While clinical reasoning has been described as the guiding force in a therapeutic practice, we are only just beginning to understand the nature of reasoning and reflection and how clinicians think. Further research is required to build and test the emerging theory of clinical reasoning in occupational therapy.

Electro-mechanic steering device for head-lamp mounted miniature video cameras

Endoscopic or microscopic video recordings set a widely established standard for medico-legal documentation of operative procedures. In addition, they are an essential part of undergraduate as well as postgraduate medical education. Macroscopic operations in the head and neck can be recorded by miniaturised video cameras attached to the surgeon's head lamp. The authors present an electro-mechanic steering device which has been designed to overcome the parallax error created with a head-mounted video camera, especially as the distance of the camera to the operative field varies. The device can be operated by the theatre staff, while the sterility of the operative field is maintained and the surgeon's physical working range remains unrestricted. As the video image is reliably centred to the operative field throughout the procedure, a better orientation and understanding for spectators who are unfamiliar with the surgical steps is obtained. While other adverse factors to macroscopic head-mounted video recordings, such as involuntary head movements of the surgeon, remain unchanged, the device adds to a higher quality of video documentation as it relieves the surgeon from adjusting the image field to the regions of interest. Additional benefit could be derived from an auto-focus feature or from image stabilising devices.

Using a head-mounted video camera to study clinical reasoning.

Studies of clinical reasoning are essential if we are to extend our knowledge of occupational therapy practice, better communicate our work to clients and colleagues, and reveal to our students the nuances of therapy that cannot be gained from texts. However, accessing therapists' clinical reasoning is not an easy task because these cognitive processes can be studied only indirectly. The aim of this article is to promote the study of clinical reasoning by reviewing a new approach to data collection in this field. To achieve this purpose, the article outlines current data collection methods, such as the think-aloud method written notes, free recall, and audio-assisted and video-assisted recall. A novel method involving a head-mounted video camera is described, and details are provided on a modified approach to debriefing using video-assisted recall. Anecdotes from the authors experience of using this technology illustrate the text.

The Clinical Reasoning of Novice and Expert Occupational Therapists

Over the past 15 years, research in health sciences has consistently shown that differences in the performance of novice and expert clinicians are predominantly due to their clinical reasoning abilities. Furthering our knowledge of the ways expert and novice occupational therapists reason can help us to explicate the complexities of practice and ultimately assist novices to think like experts. This paper presents the findings of a study which investigated qualitatively and quantitatively the clinical reasoning of novice and expert occupational therapists. Three expert and two novice occupational therapists working in rehabilitation settings wore head-mounted video cameras while completing three therapy sessions (assessment, treatment, discharge planning). Therapists then viewed the videos and reported back on their reasoning. These verbal reports were transcribed and analysed. While the quantitative results indicated several differences in both the amounts and types of clinical reasoning used by novices and experts, the qualitative analyses were more useful in revealing differences in the ways these two groups presented their clinical reasoning. The findings suggest that novice therapists could benefit from spending more time reflecting on the therapy process, and discussing their therapy with expert colleagues.

Virtual Eyes Can Rearrange Your Body: Adaptation to Visual Displacement in See-Through, Head-Mounted Displays

Among the most critical issues in the design of immersive virtual environments are those that deal with the problem of technologically induced intersensory conflict and one of the results, sensorimotor adaptation. An experiment was conducted to support the design of a prototype see-through, head-mounted display (HMD). When wearing video see-through HMDs in augmented reality systems, subjects see the world around them through a pair of head-mounted video cameras. The study looked at the effects of sensory rearrangement caused by a HMD design that displaced the user's “virtual” eye position forward (165 mm) and above (62 mm) toward the spatial position of the cameras. The position of the cameras creates images of the world that are slightly downward and inward from normal. Measures of hand-eye coordination and speed on a manual pegboard task revealed substantial perceptual costs of the eye displacement initially, but also evidence of adaptation. Upon first wearing the video see-through HMD, subjects' pointing errors increased significantly along the spatial dimensions displaced (the y dimension, above-below the target, and z dimension, in front-behind the target). Speed of performance on the pegboard task decreased by 43% compared to baseline performance. Pointing accuracy improved by approximately 33% as subjects adapted to the sensory rearrangement, but it did not reach baseline performance. When subjects removed the see-through HMD, there was evidence that their hand-eye coordination had been altered. Negative aftereffects were observed in the form of greater errors in pointing accuracy compared to baseline. Although these aftereffects are temporary, the results may have serious practical implications for the use of video see-through HMDs by users (e.g., surgeons) who depend on very accurate hand-eye coordination.

Head-Mounted Video Camera System in Testing Multihandicapped Children with Low Vision

Vision testing with multihandicapped children is more difficult than with normally developed children: the child's ability to concentrate in the test situation is often markedly reduced, or the child is not capable of communicating with the examiner in the normal way owing to deficiencies in motor skills, hearing, or speech. Often observation of the eyes and face is difficult because of bent-down sitting position caused by poor control of head and neck. By recording the test situation on a video tape it is possible to analyse the child's reactions afterwards more accurately. Our video system consists of a miniature video camera attached to the head of the child with a small mirror in front of the camera to provide a picture of the eyes. Simultaneous recording of the eye movements and the fixation target is possible by adjusting the position of the mirror so that it covers the view of the camera only partially. With the aid of a second, conventional video camera, we get an overview picture of the test situation. This picture is combined with the image of the miniature camera on the child's head and recorded on a video tape. With our video system it is possible to see the eye movements even when the child's head is bent-down or the child is moving in the examination room. It also allows the use of full-field stimuli covering the eyes as in examination of the optokinetic nystagmus. The eye - hand coordination can also be monitored on the video tape.

Studying complex decision making in natural settings: using a head-mounted video camera to study competitive orienteering.

Head-mounted video recording is described as a potentially powerful method for studying decision making in natural settings. Most alternative data-collection procedures are intrusive and disruptive of the decision-making processes involved while conventional video-recording procedures are either impractical or impossible. As a severe test of the robustness of the methodology we studied the decision making of 6 experienced orienteers who carried a head-mounted light-weight video camera as they navigated, running as fast as possible, around a set of control points in a forest. Use of the Wilcoxon matched-pairs signed-ranks test indicated that compared with free recall, video-assisted recall evoked (a) significantly greater experiential immersion in the recall, (b) significantly more specific recollections of navigation-related thoughts and feelings, (c) significantly more realizations of map and terrain features and aspects of running speed which were not noticed at the time of actual competition, and (d) significantly greater insight into specific navigational errors and the intrusion of distracting thoughts into the decision-making process. Potential applications of the technique in (a) the environments of emergency services, (b) therapeutic contexts, (c) education and training, and (d) sports psychology are discussed.