J. Christopher Brill

Body Orientation and the Perception of Spatial Auditory and Tactile Cues

This study investigated the effects of five body orientations (supine, kneeling, sitting, standing, and prone) on perception of spatial auditory and spatial tactile cues along eight equidistant points (45° separation) of the azimuth, using a within-participant design. Participants (N = 30) used a graphics tablet and stylus to indicate the perceived direction indicated by either vibrotactile stimuli applied to the abdomen, or spatial auditory stimuli presented via headphones. Response time data show responses to spatial tactile cues were significantly faster than spatial auditory cues at each body position and for each point along the azimuth, with no significant effects of body orientation. Absolute angle differences between presented and perceived cues were significantly smaller in the tactile condition for five of the eight stimulus positions, with no significant effects of body orientation. Results are discussed in terms of designing multi-sensory directional cues for reducing visual search space for dismounted soldiers

Multimodal cueing: The relative benefits of the auditory, visual, and tactile channels in complex environments

Determining the most effective modality or combination of modalities for presenting time sensitive information to operators in complex environments is critical to effective display design. This panel of display design experts will briefly review the most important empirical research regarding the key issues to be considered including the temporal demands of the situation, the complexity of the information to be presented, and issues of information reliability and trust. Included in the discussion will be a focus on the relative benefits and potential costs of providing information in one modality versus another and under what conditions it may be preferable to use a multisensory display. Key issues to be discussed among panelists and audience members will be the implications of the existing knowledge for facilitating the design of alerts and warnings in complex environments such as aviation, driving, medicine and educational settings.

Tactile Technology for Covert Communications

The modern battlefield is an environment replete with information and distractions, often to the detriment of communication. To circumvent these issues, we developed TACTICS, a tactile display capable of covertly communicating directional cues and traditional U.S. Army Hand-Arm signals. A multi-pronged, human-centered approach was used to develop TACTICS, and specific considerations for general tactile display are discussed with TACTICS as an exemplar. Laboratory and field research suggest TACTICS is a highly effective means of communication by presenting tactile icons that are learned quickly, perceived intuitively, and discriminated successfully.

Indexing Cognitive Reserve Capacity: A Multi-modal Approach

The Multi-Sensory Workload Assessment Protocol (M-SWAP) is a newly developed standardized measure of cognitive reserve capacity. It is consists of a multi-modal counting task administered in a dual task environment. The goal of the present work was to further validate the measure by assessing the demand manipulation and perceived workload. Significant differences in performance and perceived workload were observed across demand levels, but not across modalities. These results suggest the secondary task protocol imposes demand in a manner consistent with the proposed model.

Effect of task modality on dual-task performance, response time, and ratings of operator workload

The purpose of this study was to use established measures of attentional reserve capacity to test for the existence of tactile-specific resources in the context of Wickens’ (1984, 2002) Multiple Resource Theory. Participants performed a primary counting task in the tactile modality and were presented with a concurrent secondary attention task in the visual, auditory, and tactile modalities. The data indicate a significant difference in performance based on whether the dual-task conditions were performed crossmodally or unimodally, in terms of percent correct and response time to target stimuli. Specifically, participants performed significantly worse in tactile-tactile dual-task conditions, suggesting performance was degraded as a function of resource depletion. Furthermore, participants rated the unimodal dual-task conditions as significantly harder, using a subjective workload rating, than either of the dual-task crossmodal conditions, or the single task condition. The results suggest that task interference was a function of resource limitation rather than structural interference, providing direct empirical evidence supporting the inclusion of tactile resources in Wickens’ Multiple Resource Theory.

Effects of Secondary Loading Task Modality on Attentional Reserve Capacity

The purpose of the present study was to use a newly-developed measure of reserve attentional capacity to evaluate unitary versus multiple resource theories of attention. Participants performed a primary visual monitoring task and were presented with visual, auditory, and tactile secondary loading tasks. The data indicate that participants maintained performance on the primary task, as instructed, and performed the secondary task with any remaining attentional reserve capacity. A significant difference was found on the basis of secondary task modality, wherein performance on the visual secondary task was significantly worse than that of secondary auditory and tactile tasks. This result was additionally supported by scores on a subjective workload questionnaire. Although the data do not preclude interpretation in terms of a unitary resource model, data trends offer potential support for a multiple resource model.

A Wireless Tactile Communication System for Conveying U.S. Army Hand-Arm Signals

Combat conditions place fearsome extremes on soldier senses, rendering many traditional visual and auditory informational pathways unusable for soldier communications. To circumvent these limitations, vibrotactile displays may offer environmental advantages (covert use in murky and noisy conditions) as well as human information processing advantages (an unimpeded sensory channel and potential resource pool). The demonstrated system uses wireless electronic communications to present exemplar Army arm and hand signals in a tactual form. Vibrotactors on an elasticized belt deliver vibrotactile patterns to the wearers torso, with inputs originating from a hardened PDA running a custom software package. Benefits and limitations are discussed, as well as other potential applications and integrations with other information input sources.

Search Space Reduction via Multi-Sensory Directional Cueing

Spatial tactile displays allow for the cueing of directional information without drawing upon the visual and auditory channels. This work highlights the effectiveness of a tactual display versus a spatial auditory display baseline for augmenting a visual search task. Touch provides highly salient and covert signals that narrow the visual search space, potentially shortening response times, improving accuracy, and imposing minimal additional demand upon visual and auditory channels. Applications of this display technology for spatial location of targets include acquisition of potential threats in simulated and real combat environments, as well as improved localization of objects for first responders or for those with sensory impairments.

Effects of Alarm Modality and Alarm Reliability on Workload, Trust, and Driving Performance:

As roads are getting more congested, the rate of automobile crashes due to driver error is also rising. Driving is an attention demanding task. The automobile industry has developed collision avoidance warning systems to increase situation awareness and roadway safety. Different modalities of alarms could be used to increase drivers’ situation awareness. The current study is a preliminary analysis of the effects of alarm reliability (70% & 90%) and alarm modality (auditory & tactile) on driver performance, trust in alarms, and perceived workload. Participants (n=5) drove in a simulated environment. The results showed that drivers had fewer collisions in the tactile condition than the auditory condition. The findings of this research can inform which alarm modality is effective in improving driver performance and how practitioners can use this information to improve collision avoidance warning systems to increase roadway safety.

Gender differences and aggressive driving behavior: a factor analytic study

Aggressive driving behavior can be manifested in a wide variety of unsafe driving practices such as tailgating, honking, obscene and rude gestures, flashing high beams at slower traffic, and speeding. According the National Highway Traffic Safety Administration 2000 report, aggressive driving was a major cause of traffic accidents and injury. The present study was designed to systematically examine 5 previously developed scales related to aggressive driving behavior using a factor analytic approach. A sample of 253 students were administered these five questionnaires and the data were coded and statistically analyzed using a principal components analysis with Varimax rotation on the 81 items of the five combined scales. Nineteen components accounting for 67.4% of the variance were retained. Component scores were computed for the 19 components and then correlated with gender. Three significant (p < .05) positive rs were found between gender; factors 11 (bright lights action), 12 (delaying action), and 19 (driving drunk). Males in the sample reported performing these actions more than females. There was one negative r between gender and factor 4 (considerate thoughts), suggesting that females reported more pleasant thoughts than males when angered or annoyed on the road.