Aerospace Engineering

How is performance under pressure influenced by the history of events that precede it, and how does the pressure outcome influence the series of events that follow? A baseball batting simulation was used with college players to investigate these questions. In Experiment 1, the difficulty of the simulation was first adaptively adjusted to equate performance level. Batters next completed 20 at-bats used to classify them into one of three performance groups (normal, cold streak, or hot streak) followed by a one at-bat pressure condition. Finally, performance was evaluated over a period of 20 postpressure at-bats. In Experiment 2, a series of secondary tasks were added to assess attentional focus. In both experiments, whether batters succeeded or failed under pressure was significantly related to their performance history immediately before the pressure event, with the normal group having the poorest pressure performance. Performance postpressure was significantly related to both the pressure outcome and prepressure performance. These performance effects were related to changes in the batter's attentional focus as shown by changes in secondary task accuracy.

Bat/ball contact produces visual (the ball leaving the bat), auditory (the "crack" of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation between the point of contact and "sweet spot") was compared for no feedback (N), visual alone, auditory alone, and tactile alone. Swings were more accurate for all single-modality combinations as compared to no feedback, and visual produced the greatest accuracy. In Experiment 2, the congruency between visual, tactile, and auditory was varied so that in some trials, the different modalities indicated that the simulated ball contacted the bat at different points. Results indicated that batters combined information but gave more weight to visual. Batting training manuals, which typically only discuss visual cues, should emphasize the importance of auditory and tactile feedback in baseball batting.

This study examined the effect of the stimulus-response (S-R) compatibility of pedestrian collision warnings presented via different sensory modalities in a driving simulator. Despite the well-established fact that reaction times (RT) are faster under S-R compatible conditions, the majority of collision warning research has used S-R incompatible warnings (i.e., the warning comes from the direction of the obstacle to be avoided not the desired response direction). Thirty-two participants in a fixed-base driving simulator drove on a three-lane urban road in which pedestrians randomly walked from the sidewalk into the roadway. Collision warnings in two different modalities (tactile and auditory) were compared with a no warning condition. Participants were equally divided into one of four conditions representing all combinations of two levels of warning S-R compatibility (compatible and incompatible) and two levels of warning timing (early and late). For early warnings, incompatible warnings were most effective as shown by a significantly shorter steering RT and larger clearance distance. For late warnings, compatible warnings were most effective. For early warnings, RTs were significantly faster in the tactile condition. The relationship between collision warning effectiveness and S-R compatibility in driving is dependent on whether the driver has time to evaluate the situation before collision will occur. Our findings have important implications for the design of effective tactile and auditory collision warning systems. However, further research is needed to determine if these effects occur in more representative driving conditions (e.g., lower pedestrian incursion rate and unreliable warnings).

The ability to inhibit an ongoing action in response to a signal from the environment is important for many perceptual-motor actions. This paper examines a particular example of this behavior: attempting to inhibit or "check" a swing in baseball batting. A model of motor inhibition in batting is proposed. In the model there are three different inhibition signals (out of range launch angle, early expected-actual trajectory discrepancy, and late expected-actual trajectory discrepancy) resulting in four possible response outcomes for the batter's swing (full swing, inhibited swing, partial response, or interrupted swing). The predictions of the model were compared with the actual batting performance of 20 baseball players using a high-fidelity batting simulator. The proportions of the different response outcomes could be explained by the inhibition model for 17/20 of the batters in the study. These findings suggest that models of motor inhibition developed for simple, discrete tasks can be applied to complex, multistage behaviors. This batting inhibition model could be used to provide a quantitative measure of a player's bat control for training and player-screening purposes.

Objective: This study examined the effectiveness of rear-end collision warnings presented in different sensory modalities as a function of warning timing in a driving simulator. Background: The proliferation of in-vehicle information and entertainment systems threatens driver attention and may increase the risk of rear-end collisions. Collision warning systems have been shown to improve inattentive and/or distracted driver response time (RT) in rear-end collision situations. However, most previous rear-end collision warning research has not directly compared auditory, visual, and tactile warnings. Method: Sixteen participants in a fixed-base driving simulator experienced four warning conditions: no warning, visual, auditory, and tactile. The warnings activated when the time-to-collision (TTC) reached a critical threshold of 3.0 or 5.0 s. Driver RT was captured from a warning below critical threshold to brake initiation. Results: Drivers with a tactile warning had the shortest mean RT. Drivers with a tactile warning had significantly shorter RT than drivers without a warning and had a significant advantage over drivers with visual warnings. Conclusion: Tactile warnings show promise as effective rear-end collision warnings. Application: The results of this study can be applied to the future design and evaluation of automotive warnings designed to reduce rear-end collisions.

We investigated the haptic cuing of visual attention using spatially-predictive (75% valid) and spatiallynonpredictive (25%) haptic cues. The participants performed a visual change detection task immediately following a haptic spatial cue whose location corresponded to one of the four visual quadrants. The participants were explicitly instructed to use the spatially-predictive haptic cues but to try and ignore the spatially-nonpredictive cues. In addition to reaction time (RT) data, we recorded participants' eyeposition in order to provide a direct measure of overt visual attention. The results indicated that the spatially-predictive haptic cues reduced the amount of time taken to detect the visual changes, as expected. The spatially-nonpredictive cues increased visual search latencies, indicating that the cues could not be ignored completely. There was also evidence that haptic cuing served to alert the participants resulting in an overall reduction of response latencies.

Predicting an action's outcome before complete sensory feedback has been received is highly advantageous in sensorimotor skills. A basketball player is more likely to rebound a miss if that miss is predicted before the ball hits the rim. And, in baseball, knowing where one's hit will land gives the batter a base-running advantage. Although one might suppose that high-level athletes are better at such predictions than novices, this has neither been directly tested nor has a mechanism underlying an expertise advantage (if it does exist) been established. Insight into such skill level differences will not only illuminate the mechanisms governing outcome prediction, but may provide new insight into the cognitive processes supporting execution across the learning continuum. How might outcomes be predicted? By definition, direct sensory feedback from the environment is not available. Therefore, outcome cues must be extracted from the information that is available when the prediction is made: Internally generated information about the performance itself and/or expectations about anticipated performance outcomes.

Many authors have assumed that motor actions required for collision avoidance and for collision achievement (for example, in driving a car or hitting a ball) are guided by monitoring the time to collision (TTC), and that this is done on the basis of moment-tomoment values of the optical variable τ [1-3]. This assumption has also motivated the search for single neurons that fire when τ is a certain value [4-8]. Almost all of the laboratory studies and all the animal experiments were restricted to the case of stationary observer and moving object. On the face of it, this would seem reasonable. Even though humans and other animals routinely perform visually guided actions that require the TTC of an approaching object to be estimated while the observer is moving, τ provides an accurate estimate of TTC regardless of whether the approach is produced by self-motion, object-motion or a combination of both. One might therefore expect that judgements of TTC would be independent of selfmotion. We report here, however, that simulated selfmotion using a peripheral flow field substantially altered estimates of TTC for an approaching object, even though the peripheral flow field did not affect the value of τ for the approaching object. This finding points to long range interactions between collisionsensitive visual neurons and neural mechanisms for processing self-motion.

We measured the precision (i.e. Weber fraction) and the accuracy with which the time to collision (TTC) with a simulated approaching object is estimated. We simulated a rigid spherical object and a rigid nonspherical object (an oblate spheroid whose longer axis was vertical). We used the following viewing conditions: that the available information about TTC was only monocular (M), only binocular (B) and monocular plus binocular (M and B). In addition to the approaching SPHERE condition, we used the following three simulation conditions for the oblate spheroid: (2) a slow rotation through 90°(SIDE-END); (3) a slow rotation through 90°(END-SIDE); (4) several complete rapid rotations (RROT). Weber fractions for discriminating TTC were similar for all 12 combinations of viewing and simulation conditions. When only monocular information was available, perceived TTC was longer in the M/SIDE-END condition than in the M/SPHERE condition, and shorter in the M/ END-SIDE condition than in the M/SPHERE condition. As well, observers were strongly influenced by task-irrelevent variables in the M/SIDE-END condition so that they could not properly perform the task. The addition of binocular information considerably improved the accuracy of estimating TTC in simulation conditions SPHERE, END-SIDE and RROT, and allowed reliably accurate estimations to be made in the SIDE-END simulation condition. We suggest that, when binocular information is combined with monocular information about TTC, the two kinds of information are weighted roughly equally when the approaching object is a rigid sphere, but the binocular information is weighted more heavily when the approaching object is nonspherical and rotating.

The purpose of the present study was to investigate the perceptualmotor strategies used by drivers during left-turn execution as a means of identifying potential causes of such accidents and to inform the design of left-turn warnings. Twenty-one participants executed a series of left turns in a driving simulator. The initial distance(D) and time to intersection(TTI) of an oncoming vehicle were varied orthogonally to present drivers with a range of different safety margins. The initial distance values ranged from 50 to 150m, and the TTI values ranged between 4 to 12 sec. Accidents occurred on roughly 3% of the trials, with large individual differences in performance. The most common conditions for accidents to occur involved a large value of D(>=100) and a medium-short value of TTI(<=6). The timing of left-turn initiation was significantly affected by both the TTI and the distance of the oncoming vehicle. On average, left turns were initiated at a shorter TTI when the distance was large. We conclude that since there were several instances in which drivers used the unsafe strategy of basing their decision to turn on the distance of the oncoming vehicle, a left-turn warning that is based on temporal information alone (e.g., Nowakowski, 2006) will likely be unreliable, because the decision to turn is not solely based on temporal information.

The concept of sustainable development (hereafter SD) has a pre-eminent place in the environmental policy agenda where it is defined as "development which meets the needs of the present without compromising the ability of future generations to meet their own needs" (UNWCED, 1987, p8). Within the accounting literature research activity has been focused on what SD may mean for business and accounting activity (see, for example,

A series of three experiments was designed to investigate whether the presentation of moving tactile warning signals that are presented in a particular spatiotemporal configuration may be particularly effective in terms of facilitating a driver's response to a target event. In the experiments reported here, participants' visual attention was manipulated such that they were either attending to the frontal object that might occasionally approach them on a collision course, or else they were distracted by a color discrimination task presented from behind. We measured how rapidly participants were able to initiate a braking response to a looming visual target following the onset of vibrotactile warning signals presented from around their waist. The vibrotactile warning signals consisted of single, double, and triple upward moving cues (Experiment 1), triple upward and downward moving cues (Experiment 2), and triple random cues (Experiment 3). The results demonstrated a significant performance advantage following the presentation of dynamic triple cues over the static single tactile cues, regardless of the specific configuration of the triple cues. These findings point to the potential benefits of embedding dynamic information in warning signals for dynamic target events. These findings have important implications for the design of future vibrotactile warning signals.

Four experiments were conducted in order to assess the effectiveness of dynamic vibrotactile collision-warning signals in potentially enhancing safe driving. Auditory neuroscience research has demonstrated that auditory signals that move toward a person are more salient than those that move away. If this looming effect were found to extend to the tactile modality, then it could be utilized in the context of in-car warning signal design. The effectiveness of various vibrotactile warning signals was assessed using a simulated car-following task. The vibrotactile warning signals consisted of dynamic toward-/away-from-torso cues (Experiment 1), dynamic versus static vibrotactile cues (Experiment 2), looming-intensity- and constant-intensity-toward-torso cues (Experiment 3), and static cues presented on the hands or on the waist, having either a low or high vibration intensity (Experiment 4). Braking reaction times (BRTs) were significantly faster for toward-torso as compared to away-fro...

Previous research on smart phone use while driving has primarily focused on phone calls and texting. Drivers are now increasingly using their phone for other activities during driving, in particular social media, which have different cognitive demands. The present study compared the effects of four different smart phone tasks on car-following performance in a driving simulator. Phone tasks were chosen that vary across two factors: interaction medium (text vs image) and task pacing (self-paced vs experimenter-paced) and were as follows: Text messaging with the experimenter (text/other-paced), reading Facebook posts (text/ self-paced), exchanging photos with the experimenter via Snapchat (image, experimenter-paced), and viewing updates on Instagram (image, experimenter-paced). Drivers also performed a driving only baseline. Brake reaction times (BRTs) were significantly greater in the text-based conditions (Mean = 1.16 s) as compared to both the image-based conditions (Mean = 0.92 s) and the baseline (0.88 s). There was no significant difference between BRTs in the image-based and baseline conditions and there was no significant effect of task-pacing. Similar results were obtained for Time Headway variability. These results are consistent with the picture superiority effect found in memory research and suggest that image-based interfaces could provide safer ways to "stay connected" while driving than text-based interfaces.

Sustainability and social responsibility appear to be occupying a place of increasing importance in the discourse surrounding business and organisation. As this discourse gains acceptance organisations seek for ways to measure and manage their interactions in the field. Simultaneously, societal concerns for the way in which organisations represent themselves with respect to social responsibility and sustainability stimulate a need for wider accountability. This essay joins a steadily growing trickle of papers which attempt to articulate and make sense of social accounting, accountability and reporting and, in so doing, offer suggestions for future directions in research, teaching and/or practice. The&lt;br /&gt;primary purpose of this paper is to offer a view of developments in social&lt;br /&gt;accounting in the last decade or so and to emphasise something I fear we&lt;br /&gt;are in danger of losing – namely that sense of the importance of social accounting and the considerable cr...

Mack and Rock's research (1999), suggests that we perceive only those objects and events to which we directly attend. This means that the majority of unexpected visual information goes unnoticed, no matter how dramatic or important it may be. Not noticing unexpected objects in direct view because your attention is on other driving events is a potentially deadly but common phenomenon. Most drivers have experienced these brief moments of "functional blindness" and not perceived events or objects directly and obviously centered in their field of vision. This usually produces astonishment, alarm, and possible over-reaction when awareness returns. The driver may be telling the truth to the officer after the crash, "I did not see that stop sign!"