Benjamin A. Clegg

Representing Serial Action and Perception

This article presents a review on the representational base of sequence learning in the serial reaction time task. The first part of the article addresses the major questions and challenges that underlie the debate on implicit and explicit learning. In the second part, the informational content that underlies sequence representations is reviewed. The latter issue has produced a rich and equivocal literature. A taxonomy illustrates that substantial support exists for associations between successive stimulus features, between successive response features, and between successive response-to-stimulus compounds. We suggest that sequence learning is not predetermined with respect to one particular type of information but, rather, develops according to an overall principle of activation contingent on task characteristics. Moreover, substantiating such an integrative approach is proposed by a synthesis with the dual-system model (Keele, Ivry, Mayr, Hazeltine, & Heuer, 2003).

Interruption management: the use of attention-directing tactile cues.

Previous research has suggested that providing informative cues about interrupting stimuli aids management of multiple tasks. However, auditory and visual cues can be ineffective in certain situations. The objective of the present study was to explore whether attention-directing tactile cues aid or interfere with performance. A two-group posttest-only randomized experiment was conducted. Sixty-one participants completed a 30-min performance session consisting of aircraft-monitoring and gauge-reading computer tasks. Tactile signals were administered to a treatment group to indicate the arrival and location of interrupting tasks. Control participants had to remember to visually check for the interrupting tasks. Participants in the treatment group responded to more interrupting tasks and responded faster than did control participants. Groups did not differ on error rates for the interrupting tasks, performance of the primary task, or subjective workload perceptions. In the context of the tasks used in the present research, tactile cues allowed participants to effectively direct attention where needed without disrupting ongoing information processing. Tactile cues should be explored in a variety of other visual, interruptladen environments. Potential applications exist for aviation, user-interface design, vigilance tasks, and team environments.

Stimulus-specific sequence representation in serial reaction time tasks

Some recent evidence has favoured purely response-based implicit representation of sequences in serial reaction time tasks. Three experiments were conducted using serial reaction time tasks featuring four spatial stimuli mapped in categories to two responses. Deviant items from the expected sequence that required the expected response resulted in increased response latencies. The findings demonstrated a stimulus-specific form of representation that operates in the serial reaction time task. No evidence was found to suggest that the stimulus-specific learning was contingent on explicit knowledge of the sequence. Such stimulus-based learning would be congruent with a shortcut within an information-processing framework and, combined with other research findings, suggests that there are multiple loci for learning effects.

Encoding and representation of simultaneous and sequential arrays in visuospatial working memory

The effect of presentation type on organization in visuospatial working memory (VSWM) was examined. Stimuli were presented sequentially or simultaneously at study, and participants made same/different judgements at test. The test array varied in four different spatial configuration conditions: one featuring no changes from study, one in which two items switched, one in which the same array repeated but in a different location, and one in which a completely novel test stimulus appeared. Results indicated the use of a global configuration for both simultaneous and sequential presentations and showed increased impairment of item-level knowledge with sequential presentations. Overall, these results support the use of a global configuration organization as a fundamental aspect of VSWM processing.

Complacency and automation bias in the use of imperfect automation

Objective We examine the effects of two different kinds of decision-aiding automation errors on human–automation interaction (HAI), occurring at the first failure following repeated exposure to correctly functioning automation. The two errors are incorrect advice, triggering the automation bias, and missing advice, reflecting complacency. Background Contrasts between analogous automation errors in alerting systems, rather than decision aiding, have revealed that alerting false alarms are more problematic to HAI than alerting misses are. Prior research in decision aiding, although contrasting the two aiding errors (incorrect vs. missing), has confounded error expectancy. Method Participants performed an environmental process control simulation with and without decision aiding. For those with the aid, automation dependence was created through several trials of perfect aiding performance, and an unexpected automation error was then imposed in which automation was either gone (one group) or wrong (a second group). A control group received no automation support. Results The correct aid supported faster and more accurate diagnosis and lower workload. The aid failure degraded all three variables, but “automation wrong” had a much greater effect on accuracy, reflecting the automation bias, than did “automation gone,” reflecting the impact of complacency. Some complacency was manifested for automation gone, by a longer latency and more modest reduction in accuracy. Conclusions Automation wrong, creating the automation bias, appears to be a more problematic form of automation error than automation gone, reflecting complacency. Implications Decision-aiding automation should indicate its lower degree of confidence in uncertain environments to avoid the automation bias.

Workload overload modeling: An experiment with MATB II to inform a computational model of task management

Task switching choice was examined building from a model of task overload management. An experiment using the Multi-Attribute Task Battery (MATB) was undertaken to explore the influence of two parameters of the model, task priority and task difficulty. Participants were free to switch between the four component tasks, with the number of switches and task choice for conflicting events observed. A unique post-experiment survey measured subjective ratings of task attributes. We found that task difficulty, by reducing switching, and task priority, which determined whether increased task difficulty increased time in task, significantly influenced task switching predominantly in line with our predictions. The specific role of priority in multi-task management, and future directions including time-on-task related effects and the role of operator fatigue, are discussed.

Implicit motor sequence learning is not represented purely in response locations

This study employed a novel variant of the serial reaction time task, focused on sequencing one element of movement—direction. During the task a repeated pattern of alternating directions (right–left–right, etc.) was embedded in the stimuli, and there was no series of response locations. Responses were made via two effector systems: single-finger responding (necessitates lateral arm movements between response keys), and four-fingered responding (4 individual fingers on 4 individual keys; requires no lateral arm movement). The sequence of directions was only learned by participants who performed lateral movements during training, indicating that learning was contingent on the particular motor effector used. Participants with low levels of sequence awareness displayed the same pattern of results.

The Role of Working Memory in Levels of Situation Awareness

Situation awareness (SA) brings together theories in cognition to examine what an operator perceives, understands and predicts about their environment. Previous characterization of working memory (WM) influence in levels of awareness however is sparse and has several shortcomings, including how both WM and SA have been measured. In the current experiment, a factor analytic approach to WM was adopted based on performance on three different WM tasks. These factor scores were then related to SA which was measured over two forms of scenarios in a complex dynamic decision-making task. In one scenario, Level 1 SA was assessed, and the other assessed Level 3 processes implicitly. Findings from 99 participants indicate WM was unrelated to Level 1, but was related to Level 3 SA with the relationship strengthening with increasing task experience. These results refine and contribute to ongoing theory in the context of SA and dynamic task performance, and provide future directives to individual differences research in human factors.

Time Sharing Between Robotics and Process Control Validating a Model of Attention Switching

Objective: The aim of this study was to validate the strategic task overload management (STOM) model that predicts task switching when concurrence is impossible. Background: The STOM model predicts that in overload, tasks will be switched to, to the extent that they are attractive on task attributes of high priority, interest, and salience and low difficulty. But more-difficult tasks are less likely to be switched away from once they are being performed. Method: In Experiment 1, participants performed four tasks of the Multi-Attribute Task Battery and provided task-switching data to inform the role of difficulty and priority. In Experiment 2, participants concurrently performed an environmental control task and a robotic arm simulation. Workload was varied by automation of arm movement and both the phases of environmental control and existence of decision support for fault management. Attention to the two tasks was measured using a head tracker. Results: Experiment 1 revealed the lack of influence of task priority and confirmed the differing roles of task difficulty. In Experiment 2, the percentage attention allocation across the eight conditions was predicted by the STOM model when participants rated the four attributes. Model predictions were compared against empirical data and accounted for over 95% of variance in task allocation. More-difficult tasks were performed longer than easier tasks. Task priority does not influence allocation. Conclusions: The multiattribute decision model provided a good fit to the data. Applications: The STOM model is useful for predicting cognitive tunneling given that human-in-the-loop simulation is time-consuming and expensive.

Interruption management: A comparison of auditory and tactile cues for both alerting and orienting

Tactile and auditory cues have been suggested as methods of interruption management for busy visual environments. The current experiment examined attentional mechanisms by which cues might improve performance. The findings indicate that when interruptive tasks are presented in a spatially diverse task environment, the orienting function of tactile cues is a critical component, which directs attention to the location of the interruption, resulting in superior interruptive task performance. Non-directional tactile cues did not degrade primary task performance, but also did not improve performance on the secondary task. Similar results were found for auditory cues. The results support Posner and Petersons [1990. The attention system of the human brain. Annual Review of Neuroscience 13, 25-42] theory of independent functional networks of attention, and have practical applications for systems design in work environments that consist of multiple, visual tasks and time-sensitive information.