Quantitative effects of overlay clutter and information access effort: Examining the scan-clutter trade-off in displays with geospatial maps.

Overlaying images from multiple geospatial databases increases clutter and imposes attentional costs by disrupting focusing attention on each database and dividing attention when comparing databases. Costs of overlay clutter may offset the benefits of reduced scanning between two images displayed separately. In two experiments, we examine these attention issues using computational metrics to quantify clutter. We also examine how the scan-clutter trade-off is modified by different levels of clutter, display separation, and task attentional requirements. Participants viewed information from a geographical terrain database and a schematic map database and made judgments that required focusing attention on either database or integrating information across both. In Experiment 1, databases were presented as either overlaid or adjacent displays, and in Experiment 2, as either overlay, adjacent, or more separated displays. Results showed that response time was modulated by the magnitude of clutter, spatial separation, and task type. Results also revealed that clutter costs dominated those of spatial separation, particularly in tasks requiring focused attention. A computational feature congestion metric of clutter effectively predicted performance but could be improved by incorporating an overlay component, which amplified the costs of clutter. The results provide design guidelines for overlay displays (e.g., head-mounted displays) that will minimize the scan-clutter trade-off. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Beyond the Wizard of Oz: Negative Effects of Imperfect Machine Learning to Examine the Impact of Reliability of Augmented Reality Cues on Visual Search Performance.

Despite knowing exactly what an object looks like, searching for it in a person's visual field is a time-consuming and error-prone experience. In Augmented Reality systems, new algorithms are proposed to speed up search time and reduce human errors. However, these algorithms might not always provide 100% accurate visual cues, which might affect users' perceived reliability of the algorithm and, thus, search performance. Here, we examined the detrimental effects of automation bias caused by imperfect cues presented in the Augmented Reality head-mounted display using the YOLOv5 machine learning model. 53 participants in the two groups received either 100% accurate visual cues or 88.9% accurate visual cues. Their performance was compared with the control condition, which did not include any additional cues. The results show how cueing may increase performance and shorten search times. The results also showed that performance with imperfect automation was much worse than perfect automation and that, consistent with automation bias, participants were frequently enticed by incorrect cues.

Information Access Effort: The Role of Head Movements for Information Presented at Increasing Eccentricity on Flat Panel and Head-Mounted Displays.

OBJECTIVE: This experiment examined performance costs when processing two sources of information positioned at increasing distances using a flat panel display and an augmented reality head-mounted display (AR-HMD). BACKGROUND: The AR-HMD enables positioning virtual information at various distances in space. However, the proximity compatibility principle suggests that closer separation when two sources of information require mental integration assists performance, whereas increased separation between two sources hurts integration performance more than when a single source requires focused attention. Previous studies have provided inconsistent findings regarding costs associated with increased separation. Few of these experiments have examined separation for both focused and integration tasks, compared vertical and lateral separation, or measured head movements. METHOD: Three experiments collectively examined these issues using a flat panel display and a virtual display presented with an HMD, where the separation of information varied laterally or vertically during a focused attention (digit reading) task and an information integration (mental subtraction) task. RESULTS: There was no performance cost for either display when information was increasingly separated. However, head movements mitigated performance costs by preserving accuracy at larger separations without increasing response time. CONCLUSION: Head movements appear to mitigate performance costs associated with presenting information increasingly far apart on flat panel displays and HMDs. Both eye scanning and head movements appear to be less effortful than expected. APPLICATION: These findings have important implications for design guidelines regarding the placement of information presented on flat panel displays and, more specifically, HMDs, which can present information 360° around the user.

Visual bias could impede diagnostic accuracy of breast cancer calcifications.

Purpose: Diagnosing breast cancer based on the distribution of calcifications is a visual task and thus prone to visual biases. We tested whether a recently discovered visual bias that has implications for breast cancer diagnosis would be present in expert radiologists, thereby validating the concern of this bias for accurate diagnoses. Approach: We ran a vision experiment with expert radiologists and untrained observers to test the presence of visual bias when judging the spread of dots that resembled calcifications and when judging the spread of line orientations. We calculated visual bias scores for both groups for both tasks. Results: Participants overestimated the spread of the dots and the spread of the line orientations. This bias, referred to as the variability overestimation effect, was of similar magnitudes in both expert radiologists and untrained observers. Even though the radiologists were better at both tasks, they were similarly biased compared with the untrained observers. Conclusions: The results justify the concern of the variability overestimation effect for accurate diagnoses based on breast calcifications. Specifically, the bias is likely to lead to an increased number of false-negative results, thereby leading to delayed treatments.

Visualizing temperature trends: Higher sensitivity to trend direction with single-hue palettes.

Design plays a key role in the interpretability of complex visualizations. Many applied domains utilize large quantities of data to make predictions, ranging from maps showing the spread of infectious disease to line graphs displaying global temperature changes. These visualizations tap into the visual system's ability to extract information from groups of similar objects, a process known as ensemble processing, and the cognitive system's ability to relate visual features such as color to meaningful concepts such as disease or temperature. Visualizations must consider both perceptual and cognitive abilities. It remains unclear which best improves comprehension: visualizations designed to exploit ensemble processes or that use semantically resonant colors that align with the underlying data. To address this question, participants were shown visualizations designed for ensemble processes in that they used color encodings with only a single hue or designed for semantic processes in that they prioritized color alignment with the meaning of the data. Participants viewed stripplots using these colors and judged whether the temperature depicted in the graphs was increasing or decreasing. As quantified using the signal detection measure d', participants' sensitivity to trend information was higher with the single-hue palettes than with more semantically expressive multihue palettes. Our results suggest that visualizations may convey trend information more effectively by selecting colors that exploit ensemble processes rather than selecting semantically compatible colors. Moreover, our results showed semantic compatibility had no effect on sensitivity to trend direction. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Better sensitivity to linear and nonlinear trends with position than with color.

Useful data visualizations have the potential to leverage the visual system's natural abilities to process and summarize simple and complex information. Here, we tested whether the design recommendations made for pairwise comparisons generalize to the detection of trends. We created two different types of graphs: line graphs and stripplots. These graphs were created from identical datasets that simulated temperature changes across time. These datasets varied in the type of trend (linear and exponential). Human observers performed a trend detection task for which they judged whether the trend in temperature over time was increasing or decreasing. Participants were more sensitive to trend direction with line graphs compared to stripplots. Participants also demonstrated a systematic bias to respond that the trend was increasing for line graphs. However, this bias decreased with increasing sensitivity. Despite the better sensitivity to line graphs, more than half of the participants found the stripplots more appealing and liked them more than the line graphs. In conclusion, our results indicate that, for trend detection, depicting data with position (line graphs) leads to better performance compared to depicting graphs with color (stripplots). Yet, graphs with color (stripplots) were preferred over the line graphs, suggesting that there may be a tradeoff between the aesthetic design of the graphs and the precision in communicating the information.

Lighten Up: Specific Postural Instructions Affect Axial Rigidity and Step Initiation in Patients With Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is associated with stooped postural alignment, increased postural sway, and reduced mobility. The Alexander Technique (AT) is a mindfulness-based approach to improving posture and mobility by reducing muscular interference while maintaining upward intentions. Evidence suggests that AT can reduce disability associated with PD, but a mechanism for this effect has not yet been established. OBJECTIVE: We investigated whether AT-based instructions reduce axial rigidity and increase upright postural alignment, and whether these instructions have different effects on postural alignment, axial rigidity, postural sway, and mobility than effort-based instructions regarding posture. METHOD: Twenty subjects with PD practiced 2 sets of instructions and then attempted to implement both approaches (as well as a relaxed control condition) during quiet standing and step initiation. The "Lighten Up" instructions relied on AT principles of reducing excess tension while encouraging length. The "Pull Up" instructions relied on popular concepts of effortful posture correction. We measured kinematics, resistance to axial rotation, and ground reaction forces. RESULTS: Both sets of experimental instructions led to increases in upright postural alignment relative to the control condition. Only the Lighten Up instructions led to reduced postural sway, reduced axial postural tone, greater modifiability of tone, and a smoother center of pressure trajectory during step initiation, possibly indicating greater movement efficiency. CONCLUSION: Mindful movement approaches such as AT may benefit balance and mobility in subjects with PD by acutely facilitating increased upright postural alignment while decreasing rigidity.