Change search
Refine search result
1 - 15 of 15
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Kjelldahl, Lars
    et al.
    Schenkman, Bo
    Color inductionon computer displays – adjacency and shape effects2007In: Behavior and Information Technology, ISSN 0144-929X, E-ISSN 1362-3001, Vol. 26, no 3, p. 261-272Article in journal (Refereed)
    Abstract [en]

    The perceived interactions, induction and assimilation between colours presented on a computer screen were investigated for seven participants who gave estimates on the perceived colours. A method based on memory estimation was used. In one experiment, a red – green scale was used, while in a second experiment a white – green scale was used. The distance between objects, shape of objects and colour of objects was varied. A distance effect of colour interaction was found in both experiments, but stronger for the red – green scale. For objects adjacent to each other the interaction effects were statistically significant. For objects not adjacent to each other some smaller effects occurred. No shape effects were found. Assimilation effects were shown for the red – green colour combinations. The participants seemed to use their own internal memory scale for their judgements. A theoretical model for distance effects of colour interaction is also presented.

  • 2. Li, Wenchen
    et al.
    Schenkman, Bo
    Brunnström, Kjell
    Night Vision Systems in Cars: A Review of Principles, Experimental Results and Recommendations2008In: Ergonomia: An International Journal of Ergonomics and Human Factors, ISSN 0137-4990, Vol. 30, no 2, p. 99-114Article in journal (Refereed)
    Abstract [en]

    The effects of using a vision enhancement system when driving a car at night, especially those based on infrared image information are reviewed. Principles and a short technical background are given for night vision systems in cars. The following issues are discussed: Human vision at night, infrared image information, and human factors of night vision systems. A proposal is made for using the terms indirect viewing panel and direct viewing panel instead of the terms head up display and head down display. The advantages for older drivers are pointed out. Methodological aspects of how to study human factor aspects of night vision systems are also reviewed. Measures to be used as dependent variables are suggested: Speed, time to collision, eye movements, reaction time, lateral position of the car on the road, and the workload of the driver. Recommendations, based on visual ergonomics, taking into account different visual fields for where to put the image are given. Here suitable image distances, locations, and sizes are discussed.

  • 3. Schenkman, Bo
    Notes on Attitudes to Statistics among Swedish Psychology and Education Science Students: The Effects of Self-perception and Anxiety2010Conference paper (Other academic)
    Abstract [en]

    A number of studies have pointed out the resistance to statistics courses and the anxiety it induces among social science students. The attitudes to statistics among psychology and education science students in a new university in Sweden were studied. Seven students were from a higher level course eight were from a course at a second year level. The students were asked voluntarily to respond to a questionnaire. The higher level students were given the questionnaire both before and after the course and they were also interviewed for about one hour each. Although all students experienced anxiety about statistics, some of them had become more positive to statistics after the course. This shows that feelings of interest and anxiety can exist at the same time. The anxiety might often be a result of low self perception of one’s own mathematical abilities. This self-perception must be made more positive. Teaching statistics at the same time to both distance and campus students is not to be recommended. The students expressed a wish for a more continuous teaching of statistics, repetitions, more practical examples and practice in using statistical packages.

  • 4. Schenkman, Bo
    et al.
    Brunnström, Kjell
    Camera position and presentation scale for infrared night vision system in cars.2007In: Human Factors and Ergonomics in Manufacturing, ISSN 1090-8471 , Vol. 17, no 5, p. 457-473Article in journal (Refereed)
    Abstract [en]

    Principles of an infrared night vision system in cars were studied in a stationary car simulator. The 20 participants drove for about 45 min on a rural route in night conditions where four objects were placed in or next to the road. When the camera was mounted on the grill of the car and the scale was true size, that is, 1:1, the time to collision was the longest. Changing the scale to a wide-angle view of 1:2 decreased this time. When the camera was mounted on the roof of the car, the scale change produced an increase of the time to collision. Principal omponents analysis indicated that the speed and the lateral position of the car were independent. The results were explained partly in terms of differences between the optic arrays presented to the drivers and to motion adaptation. It is suggested that the camera for a night vision system should be placed at the level of the car grill and the presentation scale should be 1:1.

  • 5. Schenkman, Bo
    et al.
    Kjelldahl, Lars
    Color interaction – theory, examples and applications2011In: Encyclopedia of Eye Research / [ed] McGreeley, James L., Hauppauge: Nova Publishers , 2011Chapter in book (Refereed)
    Abstract [en]

    Color interaction is a perceptual effect that will influence how color combinations appear to an observer. Two main categories are color induction and color assimilation, the former when two colors become more different looking, and the latter when two colors become more similar looking. Typical examples are presentations of web pages on computer displays, cartographic pictures and maps, artistic displays such as paintings, and of environmental images, such as colors on houses. In this survey of concepts and research, the focus is on fundamental issues and definitions regarding these effects. The emphasis is on modern types of displays and relevant characteristics of different technologies are also given. Some historic perspectives are included. Different color appearance models and how they take color interaction into consideration are discussed, also including information on suitable possible color adjustments that the models may give. References are made to modern visual perceptual theories, and the place of these effects in a broader perceptual theory is considered. A number of illusions and pictures that illustrate interaction effects are included. As an example an experiment with perceived interactions between geometrical objects is described in short. Six observation colors and three interaction colors for each observed color were presented to ten observers, who performed a matching task. The result of this study is presented as color interaction diagrams in the CIELUV color space. The importance of color and color interaction in different applications is discussed together with a set of guidelines. The advantages and disadvantages that may result from using the guidelines are addressed. Some concluding remarks on possible future work in color interaction are given.

  • 6. Schenkman, Bo
    et al.
    Kjelldahl, Lars
    Color Interaction: Theory, Examples and Applications2008In: Visual Perception: New Research / [ed] Columbus, Frank, Hauppage, NY, USA: Nova Science , 2008Chapter in book (Refereed)
    Abstract [en]

    Color interaction is a perceptual effect that will influence how color combinations appear to an observer. Two main categories are color induction and color assimilation, the former when two colors become more different looking, and the latter when two colors become more similar looking. Typical examples are presentations of web pages on computer displays, cartographic pictures and maps, artistic displays such as paintings, and of environmental images, such as colors on houses. In this survey of concepts and research, the focus is on fundamental issues and definitions regarding these effects. The emphasis is on modern types of displays and relevant characteristics of different technologies are also given. Some historic perspectives are included. Different color appearance models and how they take color interaction into consideration are discussed, also including information on suitable possible color adjustments that the models may give. References are made to modern visual perceptual theories, and the place of these effects in a broader perceptual theory is considered. A number of illusions and pictures that illustrate interaction effects are included. As an example an experiment with perceived interactions between geometrical objects is described in short. Six observation colors and three interaction colors for each observed color were presented to ten observers, who performed a matching task. The result of this study is presented as color interaction diagrams in the CIELUV color space. The importance of color and color interaction in different applications is discussed together with a set of guidelines. The advantages and disadvantages that may result from using the guidelines are addressed. Some concluding remarks on possible future work in color interaction are given.

  • 7.
    Schenkman, Bo N.
    et al.
    Blekinge Institute of Technology, School of Management.
    Nilsson, Mats E.
    Blind and sighted individual´s thresholds for ordinary pitch, repetition pitch and loudness.2013Conference paper (Other academic)
    Abstract [en]

    The perceived pitch and loudness of sounds change as they fuse with reflections from nearby objects. Blind people use both sources of information, with dominance for the use of pitch. We studied if their better performance as compared to sighted can be related to the ability to discriminate tone frequency, repetition pitch and loudness. Only loudness discrimination differed between blind and sighted persons.

  • 8. Schenkman, Bo
    et al.
    Nilsson, Mats E.
    Human echolocation: Blind and sighted persons' ability to detect sounds recorded in the presence of a reflecting object2010In: Perception, ISSN 0301-0066 , Vol. 39, no 4, p. 483-501Article in journal (Refereed)
    Abstract [en]

    Research suggests that blind people are superior to sighted in echolocation, but systematic psychoacoustic studies on environmental conditions such as distance to objects, signal duration, and reverberation are lacking. Therefore, two experiments were conducted. Noise bursts of 5, 50, or 500 ms were reproduced by a loudspeaker on an artificial manikin in an ordinary room and in an anechoic chamber. The manikin recorded the sounds binaurally in the presence and absence of a reflecting 1.5-mm thick aluminium disk, 0.5 in in diameter, placed in front, at distances of 0.5 to 5 m. These recordings were later presented to ten visually handicapped and ten sighted people, 30 62 years old, using a 2AFC paradigm with feedback. The task was to detect which of two sounds that contained the reflecting object. The blind performed better than the sighted participants. All performed well with the object at < 2 in distance. Detection increased with longer signal durations. Performance was slightly better in the ordinary room than in the anechoic chamber. A supplementary experiment on the two best blind persons showed that their superior performance at distances > 2 m was not by chance. Detection thresholds showed that blind participants could detect the object at longer distances in the conference room than in the anechoic chamber, when using the longer-duration sounds and also as compared to the sighted people. Audiometric tests suggest that equal hearing in both ears is important for echolocation. Possible echolocation mechanisms are discussed.

  • 9. Schenkman, Bo
    et al.
    Nilsson, Mats E.
    Human echolocation: Pitch versus loudness information2011In: Perception, ISSN 0301-0066, E-ISSN 1468-4233, Vol. 40, no 7, p. 840-852Article in journal (Refereed)
    Abstract [en]

    Blind persons emit sounds to detect objects by echolocation. Both perceived pitch and perceived loudness of the emitted sound change as they fuse with the reflections from nearby objects. Blind persons generally are better than sighted at echolocation, but it is unclear whether this superiority is related to detection of pitch, loudness, or both. We measured the ability of twelve blind and twenty-five sighted listeners to determine which of two sounds, 500 ms noise bursts, that had been recorded in the presence of a reflecting object in a room with reflecting walls using an artificial head. The sound pairs were original recordings differing in both pitch and loudness, or manipulated recordings with either the pitch or the loudness information removed. Observers responded using a 2AFC method with verbal feedback. For both blind and sighted listeners the performance declined more with the pitch information removed than with the loudness information removed. In addition, the blind performed clearly better than the sighted as long as the pitch information was present, but not when it was removed. Taken together, these results show that the ability to detect pitch is a main factor underlying high performance in human echolocation.

  • 10. Schenkman, Bo
    et al.
    Nilsson, Mats E.
    Human echolocation: The relative importance of pitch and loudness2008Conference paper (Refereed)
    Abstract [en]

    A sound heard in the presence of a reflected object will be both louder and have a slightly different timbre (“repetition pitch”) than the same sound heard with no reflection. Thus, pitch and loudness are two sources of information that visually handicapped people may use for echolocation. In real life, the two sources of information are confounded, because perceived loudness and repetition pitch both diminishes with distance to the reflecting object. The purpose of the present experiment was to disentangle the influence of each of these sources on human echolocation. Experimental sounds were obtained from binaural recordings with an artificial head in an ordinary room. White noise (500 ms) was emitted from a loudspeaker on the chest of the artificial head. A reflecting aluminum sheet (0.5 m diameter) was located at 1, 2 and 3 m distance to the artificial head. By digital manipulation, the loudness information or the pitch information of the recorded sounds were eliminated, resulting in three kinds of sounds: (1) sounds containing both pitch and loudness information, (2) sounds with only pitch information, and (3) sounds with only loudness information. These three kinds of sounds were presented to 14 sighted students. The psychophysical method of 2-alternative-forced-choice with feedback was used, with 56 trials for each person at each condition. Each trial presented one sound recorded with, and one without, reflecting object. The task was to detect which of the two sounds that was recorded in the presence of the reflecting object. All participants could use echolocation for all three kinds of sounds at the distance of 1m, but performed close to chance with all sounds at 3 m. At the 2 m condition, sounds with only pitch information gave a higher performance compared to sounds with only loudness information, for which the performance was close to random. Thus, pitch alone may provide sufficient information for echolocation at these distances. Audiometric tests were conducted, with focus on the pure tone threshold average and the absolute difference between the ears. The results will have a bearing on the construction of orientation and mobility aids for the visually handicapped.

  • 11. Schenkman, Bo
    et al.
    Nilsson, Mats E.
    Grbic, Nedelko
    Human echolocation using click trains and continuous noise2011Conference paper (Refereed)
    Abstract [en]

    Blind people may detect objects from the information in reflected sounds, echolocation. Detection as a function of the number of clicks compared to a continuous noise was tested by presenting clicks of 5 ms with rates from 1 to 64 clicks during a 500 ms period and a 500-ms continuous white noise. The sounds were recorded in an ordinary room through an artificial binaural head. The reflecting object was an aluminum disk, diameter 0.5 m, at distances of 1 and 1.5 m. These sounds were later presented to 3 blind and 16 sighted participants in a laboratory using a 2AFC methodology. The task was to detect which of the two sounds that contained a reflecting object. Feedback was provided. The blind participants had a higher detection than the sighted, but there were also differences among the blind. These results are put in relation to physical features such as the autocorrelation function and spectral variations.

  • 12. Steffner, Daniel
    et al.
    Schenkman, Bo
    Blekinge Institute of Technology, School of Management.
    Change blindness when viewing web pages2012Conference paper (Refereed)
    Abstract [en]

    Change blindness on web pages was studied for 20 participants. The purpose was to find how change blindness appears for web pages, and which changes are easier to detect. The task was to detect if a change had occurred and to show this by the means of the cursor. Rensink´s flicker paradigm was used, where four categories of changes were presented. It was easier to detect a change not consisting of a person than one with a person. It was easier to detect a change to the left than to the right. The complexity of the web pages did not appear to have an effect, while large changes were easier to detect than small. The results may indicate that focused attention is differently sensitive for different kinds of changes. They also show that change blindness is a general phenomenon that can be applied to the perception of web pages.

  • 13. Steffner, Daniel
    et al.
    Schenkman, Bo
    Blekinge Institute of Technology, School of Management.
    Change Blindness When Viewing Web Pages2012In: Work: A journal of Prevention, Assesment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 21, no Suppl. 1, p. 6098-6102Article in journal (Refereed)
    Abstract [en]

    Change blindness on web pages was studied for 20 participants. The purpose was to find how change blindness appears for web pages, and which changes are easier to detect. The task was to detect if a change had occurred and to show this by the means of the cursor. Rensink's flicker paradigm was used, where four categories of changes were presented. It was easier to detect a change not consisting of a person than one with a person. It was easier to detect a change to the left than to the right. The complexity of the web pages did not appear to have an effect, while large changes were easier to detect than small. The results may indicate that focused attention is differently sensitive for different kinds of changes. They also show that change blindness is a general phenomenon that can be applied to the perception of web pages.

  • 14. Steffner, Daniel
    et al.
    Schenkman, Bo
    Blekinge Institute of Technology, School of Management.
    Change blindness when viewing web pages2012In: Advances in Cognitive Engineering and Neuroergonomics / [ed] Kay, M, Stanney,; Kelly, S., Hale, Boca Raton: Taylor and Francis , 2012, p. 23-32Chapter in book (Refereed)
  • 15. Yang, Yi
    et al.
    Hwang, Sheue Ling
    Schenkman, Bo
    Blekinge Institute of Technology, School of Management.
    An improved Web search engine for visually impaired users2012In: Universal Access in the Information Society, ISSN 1615-5289, Vol. 11, no 2, p. 113-124Article in journal (Refereed)
    Abstract [en]

    The Google search engine was studied as a Web prototype to be modified and improved for blind users. A Specialized Search Engine for the Blind (SSEB) was developed with an accessible interface and improved functions (searching assistance functions, user-centered functions, and specialized design for the blind). An experiment was conducted with twelve participants, both blind and sighted, to verify the effects of SSEB. The performance was better with the SSEB than with the Google search engine, and the participants also showed higher satisfactions with the SSEB. Interface considerations for designing an accessible Web site for blind users are important. The users of SSEB could in the future be expanded to include most, if not all, visually impaired people, since the World Wide Web and all Internet resources should ideally be accessible to everyone.

1 - 15 of 15
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf