An audio-tactile display

Several devices have been developed enabling the blind to adapt to digital and visual displays. Most require extensive training and are relatively expensive. The audio-tactile display described in this paper requires very little training and promises to be inexpensive. Prototypes of the display have been developed for a digital stopwatch, a digital clock, and several electronic calculators. Because the device makes use of electrical impulses to communicate with the blind, it also has numerous potential capabilities as a research tool. The device is based on a panel containing columns of braille digits that are made active through a logic circuit interfacing the braille display with a calculator or other device. The subject scans the braille columns and discovers the digits active in each column when a tone is produced simultaneously with the finger contacting the braille digit.     

Independent control of dual video subsystems on the IBM PC and compatibles

Two methods for generating video output on multiple video monitors are described. The first method involves splitting the signal from a single video adaptor card-so that multiple video monitors may be attached. Although this method is simple and relatively cost-effective, it is limited to adaptors that produce only digital video signals, thus precluding the use of VGA systems and composite displays. The second method involves the installation and programming of video adaptors: Two sample programs, which control a secondary adaptor by means of either BIOS routines or direct commands via C code, are described. Although more complex, this second method allows output to each display to be controlled independently. Furthermore, output to one screen may consist of graphics information while output to the second screen consists of text. Together, both methods can be used to create an experimental system composed of multiple data-collection stations and an independent experimenter console.     

Vection during conflicting multisensory information about the axis, magnitude, and direction of self-motion

We examined the vection induced by consistent and conflicting multisensory information about self-motion. Observers viewed displays simulating constant-velocity self-motion in depth while physically oscillating their heads left-right or back-forth in time with a metronome. Their tracked head movements were either ignored or incorporated directly into the self-motion display (as an added simulated self-acceleration). When this head oscillation was updated into displays, sensory conflict was generated by simulating oscillation along: (i) an orthogonal axis to the head movement; or (ii) the same axis, but in a non-ecological direction. Simulated head oscillation always produced stronger vection than 'no display oscillation'--even when the axis/direction of this display motion was inconsistent with the physical head motion. When head-and-display oscillation occurred along the same axis: (i) consistent (in-phase) horizontal display oscillation produced stronger vection than conflicting (out-of-phase) horizontal display oscillation; however, (ii) consistent and conflicting depth oscillation conditions did not induce significantly different vection. Overall, orthogonal-axis oscillation was found to produce very similar vection to same-axis oscillation. Thus, we conclude that while vection appears to be very robust to sensory conflict, there are situations where sensory consistency improves vection.     

Evidence for a boundary effect in roll vection

Large circular displays rotating around the line of sight produce an illusion in which the seen orientation of the true vertical is shifted in a direction opposite to the display’s motion. Two experiments were performed to determine whether the magnitude of this illusory tilt is a function of the area of display elements, of their boundary length, or of their spatial frequency. In Experiment 1, 12 subjects viewed each of nine displays across which the number and area of the circular elements were independently varied. Three of the displays were equated for the area of their elements. The results suggested that tilt magnitude and onset latency could be explained by a boundary length effect. A second experiment tested eight subjects on two displays, equated for element boundary length but differing in the spatial frequency of the elements. The displays produced closely similar illusory trite corroborating the view that, within broad limits, element boundary length—and not spatial frequency or area—determines the size and onset latency of illusory tilt. A third experiment confirmed previous research in finding greater tilt and more rapid onset with more peripherally projected displays.     

Usability of liquid crystal displays for research in the temporal characteristics of perception and attention

Recently, the use of liquid crystal displays (LCDs) in computer monitors has increased in popularity. Can LCDs produce results similar to those obtained in cathode-ray tube (CRT) displays in studies of temporal attention and perception tasks? Performance in two tasks (metacontrast masking and attentional blink) was examined using an LCD, a CRT oscilloscope, and a raster scan CRT display. Experiment 1 focused on metacontrast masking where a typical metacontrast function emerged irrespective of monitor type. Experiments 2 and 3 examined whether differences in monitors influence the attentional blink. Again, all displays elicited similar performance profiles for both the attentional blink and the trade-off between identification accuracy of the two targets. Although our results may not generalize to all LCD applications and all experimental paradigms, they indicate that LCDs can reproduce results similar to those found in metacontrast masking and attentional blink studies that were originally identified with CRT displays.     

Circular vection as a function of the relative sizes, distances, and positions of two competing visual displays

In studies where it is reported that illusory self-rotation (circular vection) is induced more by peripheral displays than by central displays, eccentricity may have been confounded with perceived relative distance and area. Experiments are reported in which the direction and magnitude of vection induced by a central display in the presence of a surround display were measured. The displays varied in relative distance and area and were presented in isolation, with one moving and one stationary display, or with both moving in opposite directions. A more distant display had more influence over vection than a near display. A central display induced vection if seen in isolation or through a 'window' in a stationary surrounding display. Motion of a more distant central display weakened vection induced by a nearer surrounding display moving the other way. When the two displays had the same area their effects almost cancelled. A moving central display nearer than a textured stationary surround produced vection in the same direction as the moving stimulus. This phenomenon is termed 'contrast-motion vecton' because it is probably due to illusory motion of the surround induced by motion of the centre. Unequivocal statements about the dominance of an eccentric display over a central display cannot be made without considering the relative distances and sizes of the displays and the motion contrast between them.     

Contextual cueing in multiple object tracking

In this study, we examined whether visual context can be learned through a dynamic display and whether it can facilitate sustained attentional tracking by combining a multiple object tracking (MOT) task and a contextual cueing procedure. The trajectories of the targets and distractors in the MOT task were made invariant by repeatedly presenting them. The results revealed that when the targets were repeatedly displayed, tracking performance implicitly improved, and this effect was enhanced when the unattended distractors in the displays were also repeated. However, the repetition of the distractors alone did not produce any effect. Interestingly, when the targets and distractors were switched in a display in which the distractors had been previously repeated, the tracking performance was impaired as compared with that in the case of nonrepeated displays. We concluded that the contextual information in a dynamic display facilitates attentional tracking and that different types of contextual modulations occurred in MOT processes, such as facilitation for attended targets and inhibition for ignored distractors.     

Workload and stress in vigilance: the impact of display format and task type

Signal salience was manipulated using configural and object displays to examine their effects on the performance, workload, and stress of vigilance. Improving performance and reducing the workload and stress of vigilance are crucial concerns. Signal salience improves performance and reduces stress, but to date there have been no salience manipulations using configural displays in a vigilance task. Two task types (individual variable monitoring and midpoint identification) and 3 display formats (bar graph-different baselines, bar graph-common baseline, and a polygon graph display) were examined. Configural displays improved performance in the midpoint identification task but not in the individual variable monitoring task. Workload depended on the form of display features (bar graph vs. polygon). Stress increased across all conditions, but task and display format did not affect stress. The midpoint identification task was associated with more emotion-focused and avoidant coping. Increasing signal salience in a vigilance task using configural displays with emergent features or physical contours can improve performance and reduce the decrement. These displays may not reduce the stress of vigilance or encourage task-focused coping. Therefore, there may be hidden costs to vigilance performance even when highly salient configural displays are used.     

Aging and implicit learning: explorations in contextual cuing

In contextual cuing, faster responses are made to repeated displays containing context-target associations than to novel displays without such covariances. We report that healthy older adults showed learning impairments in contextual cuing when compared with younger adults. The display properties in the task were altered to artificially increase younger adults' response times to match those of older adults and to produce faster responses in older participants; however, younger participants' learning remained intact, whereas older participants continued to show impairments under these conditions. These results suggest that older adults have intrinsic deficits in contextual cuing that cannot be attributed to their slower overall response speed.     

Electronic maps for terminal area navigation: effects of frame of reference and dimensionality

Two experiments are reported that contrast rotating versus fixed electronic map displays, which pilots used for a simulated approach to a landing. In Experiment 1, a rotating versus fixed-map display was experimentally crossed with a two-dimensional (2D) versus three-dimensional (3D) view (perspective map) as pilots' ability to maintain the flight path and demonstrate awareness of the location of surrounding terrain features were assessed. Rotating displays supported better flight path guidance and did not substantially harm performance on terrain awareness tasks. 3D displays led to a substantial cost for vertical control but did not differ from 2D displays in lateral control. In Experiment 2, pilots flew with the rotating 2D display and with an improved version of the rotating 3D display, designed to reduce the ambiguity of representing altitude information. Vertical control improved as a result of the 3D display design improvement, but lateral control did not. The results are discussed in terms of the costs and benefits of presenting information in 3D, ego-referenced format for both flight path control and terrain awareness.     

Circular vection as a function of foreground-background relationships

It has previously been reported that illusory self-rotation (circular vection) is most effectively induced by the more distant of two moving displays. Experiments are reported in which the relative effectiveness of two superimposed displays in generating circular vection as a function of (i) the separation in depth between them, (ii) their perceived relative distances, and (iii) which display was in the plane of focus was investigated. Circular vection was governed by the motion of the display that was perceived to be the more distant, even when it was actually nearer. However, actual or perceived distance was found to be not the crucial factor in circular vection because even when the distance between the two displays was virtually zero, vection was controlled by the display perceived to be in the background. When the displays were well separated in depth, vection was not affected by whether the near or the far display was in the plane of focus, nor by which display was fixed or pursued by the eyes.     

Effects of display complexity on location and feature inhibition

Inhibition of return refers to the lengthening of reaction times (RTs) to a target when a preceding stimulus has occupied the same location in space. Recently, we observed a robust inhibitory effect for color and shape in moderately complex displays: It is more difficult to detect a target with a particular nonspatial attribute if a stimulus with the same attribute was recently the focus of attention. Such nonspatial inhibitory effects have not generally been found in simpler displays. In the present study, we test how location-based and nonspatial inhibitory effects vary as a function of display complexity (eight, six, four, and two locations). The results demonstrated that (1) location-based inhibition effects were much stronger in more complex displays, whereas the nonspatial inhibition was only slightly stronger in more complex displays; (2) nonspatial inhibitory effects emerged at longer stimulus onset asynchronies than did location-based effects; and (3) nonspatial inhibition appeared only when cues and targets occurred in the same locations, confirming that pure feature repetition does not produce a cost. Taken together, the results are consistent with perceptual processes based on object files that are organized by spatial location. Using somewhat more complex displays than are most commonly employed provides a more sensitive method for observing the role of inhibitory processes in facilitating visual search. In addition, using a relatively wide set of cue–target timing relationships is necessary in order to clearly see how inhibitory effects operate.     

Improving adaptive display with temporally adaptive rendering.

Making computer imagery more responsive and realistic is one of the most basic goals of graphics researchers, and adaptive display is one of the primary means for achieving it. While previous displays have achieved a spatial adaptivity, our research focuses on achieving temporal adaptivity--sampling some regions not only more densely, but also more often. We use closed loop feedback to guide sampling to image regions that change significantly over space or time. Adaptive reconstruction emphasizes older samples in static settings, resulting in sharper images; and new samples in dynamic settings, resulting in images that may be blurry but are up-to-date. In terms of peak signal-to-noise ratio, this prototype produces much better image streams than nonadaptive renderers with the same simulated sampling rates. This new display also offers new opportunities for adapting to user state, allowing adaptive response both where and when it is needed. Our prototype system already responds interactively to changes in the user's viewpoint, it might also respond to any of a number of other indications of user state, including eye tracking, repeatedly manipulated objects, and biometrics.     

I'll Know What You're Like When I See How You Feel: How and When Affective Displays Influence Behavior-Based Impressions

ABSTRACT— Accumulating evidence suggests that targets' displays of emotion shape perceivers' impression of those targets. Prior research has highlighted generalization effects, such as an angry display prompting an impression of hostility. In two studies, we went beyond generalization to examine the interaction of displays and behaviors, finding new evidence of augmenting effects (behavior-correspondent inferences are stronger when behavior is accompanied by positive affect) and discounting effects (such inferences are weaker when behavior is accompanied by negative affect). Thus, the same display can have different effects on impressions depending on the behavior it accompanies. We found evidence that these effects are mediated by ascribed intentions and that they have a boundary: When behaviors and affective displays are repeated, the augmenting and discounting power of displays appears to wane.     

Effect of stationary objects on illusory forward self-motion induced by a looming display

It has previously been shown that when a moving and a stationary display are superimposed, illusory self-rotation (circular vection) is induced only when the moving display appears as the background. Three experiments are reported on the extent to which illusory forward self-motion (forward vection) induced by a looming display is inhibited by a superimposed stationary display as a function of the size and location of the stationary display and of the depth between the stationary and looming displays. Results showed that forward vection was controlled by the display that was perceived as the background, and background stationary displays suppressed forward vection by about the same amount whatever their size and eccentricity. Also, the perception of foreground-background properties of competing displays determined which controlled forward vection, and this control was not tied to specific depth cues. The inhibitory effect of a stationary background on forward vection was, however, weaker than that found with circular vection. This difference makes sense because, for forward body motion, the image of a distant scene is virtually stationary whereas, when the body rotates, it is not.     

Infants' perception of transparency

Four- and 7-month-old infants' perception of transparency was investigated with computer-generated achromatic or color displays depicting a semitransparent box occluding the center of a rod. Following habituation, infants viewed test displays consisting of either a two-color rod (corresponding to the habituation display's proximal characteristics) or a solid rod (corresponding to the distal characteristics of the event depicted by the habituation display). Looking-time results from 4-month-olds suggested perception of transparency in color displays but not in an achromatic display. An additional condition indicated that transparency perception may rely on the visibility of background texture through the transparent surface. Seven-month-olds, in contrast, provided some evidence of transparency perception in the achromatic display. Implications for the development of infants' responses to object properties and perceptual segregation are discussed.     

Mental extrapolation and representational momentum for complex implied motions

A sequence of static displays implying consistent motions of a pattern induces distortions in memory for the last-observed appearance of the pattern. These memory distortions suggest that there is an internal analogue to physical momentum called representational momentum. Two experiments are reported comparing performance on tasks in which observers must remember the final display with those in which they are instructed to extrapolate the implied motions out to the next step in the sequence. In each experiment, the memory shifts were highly correlated with the actual rates at which the implied motions were extrapolated. In addition, the memory shifts were larger when the mental extrapolations occurred along the same directions of implied motion each time. These findings suggest that the memory shifts depend both on the rate at which the mental extrapolations are performed and on how consistently they are performed.     

CowLog: Open-source software for coding behaviors from digital video

We have developed CowLog, which is open-source software for recording behaviors from digital video and is easy to use and modify. CowLog tracks the time code from digital video files. The program is suitable for coding any digital video, but the authors have used it in animal research. The program has two main windows: a coding window, which is a graphical user interface used for choosing video files and defining output files that also has buttons for scoring behaviors, and a video window, which displays the video used for coding. The windows can be used in separate displays. The user types the key codes for the predefined behavioral categories, and CowLog transcribes their timing from the video time code to a data file. CowLog comes with an additional feature, an R package called Animal, for elementary analyses of the data files. With the analysis package, the user can calculate the frequencies, bout durations, and total durations of the coded behaviors and produce summary plots from the data.     

Examining location-based and object-based components of inhibition of return in static displays

Tipper and Colleagues (e.g., Jordan & Tipper, 1998; Tipper, Driver, & Weaver, 1991; Tipper, Weaver, Jerreat, & Burak, 1994) have provided support for inhibition of return (IOR) being composed of a location-based and an object-based component. They were able to separate out the effects of locationbased and object-based IOR by using complex displays and displays that involved moving the cued object. The present study was designed to further examine the object- and location-based components of IOR in static displays. Three experiments were conducted that looked at the presence or absence of placeholder boxes on IOR. The first experiment was designed to replicate the results of Jordan and Tipper by presenting both objects and no-objects in the same display. In the second experiment, trials were blocked, and in the third experiment trials were presented in a random order. Overall, the results are inconsistent with the notion that independent object-based and location-based IOR components combine to produce the overall IOR effect and that additive effects are realized due to the context in which the trials are presented. We propose that a single inhibitory mechanism can account for the data.     

Examining location-based and object-based components of inhibition of return in static displays

Tipper and Colleagues (e.g., Jordan & Tipper, 1998; Tipper, Driver, & Weaver, 1991; Tipper, Weaver, Jerreat, & Burak, 1994) have provided support for inhibition of return (IOR) being composed of a location-based and an object-based component. They were able to separate out the effects of location-based and object-based IOR by using complex displays and displays that involved moving the cued object. The present study was designed to further examine the object- and location-based components of IOR in static displays. Three experiments were conducted that looked at the presence or absence of placeholder boxes on IOR. The first experiment was designed to replicate the results of Jordan and Tipper by presenting both objects and no-objects in the same display. In the second experiment, trials were blocked, and in the third experiment trials were presented in a random order. Overall, the results are inconsistent with the notion that independent object-based and location-based IOR components combine to produce the overall IOR effect and that additive effects are realized due to the context in which the trials are presented. We propose that a single inhibitory mechanism can account for the data.