The Same-Different task has a long and controversial history in cognitive psychology. For over five decades, researchers have had many difficulties modelling the simple task, in which participants must respond as quickly and as accurately as possible whether two stimuli are the “Same” or “Different”. The main difficulty in doing so stems from the fact that “Same” decisions are much faster than can be modelled using a single process model without resorting to post-hoc processes, a finding since coined the fast-same phenomenon. In this thesis, I evaluate the strengths and shortcomings of past modelling endeavours, deconstruct the fast-same phenomenon while exploring the role of priming as its possible mechanism, investigate coactivity as a possible architecture underlying both decision modalities, and present an accumulator model whose assumptions and parameters stem from these results that predicts Same-Different performance (both response times and accuracies) using a single-process, a finding deemed near impossible by Sternberg (1998).

Younger adults who are walking and doing additional tasks at the same time may not realize if their performance suffers, putting some at greater risk for injury and impairment during certain tasks. This thesis has addressed this confound by developing a divided attention paradigm focusing on discrete and continuous demand manipulations. The work assessed in motorcognitive processing changes with cerebral and behavioral monitoring of over-ground walking with or without cognitive tasks. Participants (n = 19, 18-35 years, 13 females) were asked to walk at their usual pace [usual walking condition (SM)], walk at their usual pace while performing a cognitive task [dual-task condition (DT)] as well as conduct a cognitive task while standing [single cognitive condition (SC)]. All participants conducted two discrete [simple response time (SRT) & go-no-go (GNG)] and two continuous cognitive tasks [N-back (NBK) & double number sequence (DNS)] of increasing demand. The study revealed significant brain and behavior interactions during the most demanding continuous cognitive task, the DNS. The findings demonstrated lower accuracy rates, slower walk speeds as well as greater cerebral oxygenation in DNS DT in comparison to single task conditions. With increasing cognitive demands and tasks, there were longer response times, as well as lower accuracy rates. The behavioral findings were qualified by marginally significant interactions in a 2 x 4 RM ANOVA between SC-DT task and demand for accuracy rate [F (3, 54) = 2.66, p = 0.06, η2 =.13], significant interactions in response time [F (2, 36) = 4.1, p = 0.026, η2 =.18] as well as significant SM-DT task and demand findings for walk speed [F (3, 54) =5.3, p = 0.003, η2 =.23]. The 2 x 2 x 4 RM ANOVA revealed significant HbO2 interactions between walking tasks (single and dual), hemisphere and demand [F (3, 54) = 5.730, p = 0.002, η2 =.24] in the DNS only. The data suggests that greater demand manipulations with continuous cognitive tasks may be sensitive to both prefrontal cortex (PFC) and behavioral assessments in younger adults (YA). Further validation of the discrete-continuous demand paradigm in motor studies may provide a basis for cognitive assessment with applications in motor learning, cognitive training, aging and more.

Posttraumatic Stress Disorder (PTSD) is marked by avoidance, arousal, re-experiencing, and negative mood and cognition. To date, these symptoms are assessed using self-report measures (e.g., the PCL-5) and clinician administered assessments (e.g., the CAPS-5). While these are the present gold-standard assessments for PTSD, they still are prone to bias on behalf of both the administrator and the patient. Presently, there is evidence that individuals with PTSD perform differently than individuals without PTSD on certain cognitive tasks that measure attention bias and avoidance behaviors. As such, creating a battery of these tasks may be a viable route for objectively measuring PTSD. In an effort to provide preliminary evidence for such a battery, we used three cognitive assessments [the Emotional Stroop Task (EST), the Visual Search Task (VST), and the Approach Avoidance Task (AAT)] to assess cognitive performance in veterans with PTSD, and veterans and civilians without PTSD. We hypothesized that veterans with PTSD would perform worse than the other groups (as measured by reaction times and accuracy scores) following the presentation of combat-related stimuli compared to negative and positive stimuli. The results indicated that veterans with PTSD were generally slower across all conditions in the EST, had lower accuracy scores on the VST, and were slower in the combat condition compared to the other control groups in the AAT. This study provides preliminary support for the hypothesis that a battery of cognitive tasks may be an effective tool for objectively identifying PTSD. Furthermore, we discuss important methodological ways in which future studies could improve the sensitivity of these tasks.

Interpersonal conflict in organizations has been recognized as a leading social stressor across occupations with detrimental effects on employee well-being and organizational outcomes. However, reliable and valid measures of conflict are scarce and even the most widely used scales are limited by weaknesses in construct definition. In order to address the need for an improved measurement tool, the 63-item Interpersonal Conflict in Organizations Scale (ICOS) was developed. The ICOS was based on a comprehensive conceptualization of conflict that defines the construct on the basis of three definitional components: disagreement, interference, and negative emotion (Barki & Hartwick, 2004). In addition, the ICOS reliably measures four conflict types, including task outcome, task process, relationship, and non-task organizational conflict. Data were collected in two phases. The phase I sample included 126 participants from a variety of occupations whose data were used for the purpose of refining the scale. The scale validation (phase II) sample consisted of 260 full-time employees, who were also representative of various occupations. Initial validity results supported significant relationships with various organizational and personal outcome variables, including depression, job satisfaction, somatic symptoms, negative emotions, turnover intentions, counterproductive work behaviors, and cardiovascular disease risk factors. Factor analytic results for the four subscales, as well as, evidence for convergent validity are reported. Overall, the ICOS is a promising new measure of conflict that offers researchers the flexibility of assessing various types of conflict while addressing the conceptual limitations of existing scales.

Interpersonal conflict in organizations has been recognized as a leading social stressor across occupations with detrimental effects on employee well-being and organizational outcomes. However, reliable and valid measures of conflict are scarce and even the most widely used scales are limited by weaknesses in construct definition. In order to address the need for an improved measurement tool, the 63-item Interpersonal Conflict in Organizations Scale (ICOS) was developed. The ICOS was based on a comprehensive conceptualization of conflict that defines the construct on the basis of three definitional components: disagreement, interference, and negative emotion (Barki & Hartwick, 2004). In addition, the ICOS reliably measures four conflict types, including task outcome, task process, relationship, and non-task organizational conflict. Data were collected in two phases. The phase I sample included 126 participants from a variety of occupations whose data were used for the purpose of refining the scale. The scale validation (phase II) sample consisted of 260 full-time employees, who were also representative of various occupations. Initial validity results supported significant relationships with various organizational and personal outcome variables, including depression, job satisfaction, somatic symptoms, negative emotions, turnover intentions, counterproductive work behaviors, and cardiovascular disease risk factors. Factor analytic results for the four subscales, as well as, evidence for convergent validity are reported. Overall, the ICOS is a promising new measure of conflict that offers researchers the flexibility of assessing various types of conflict while addressing the conceptual limitations of existing scales.

No description available.

No description available.

With the development of technology, people's viewpoints of the automobile have shifted; instead of merely a means of transportation, the automobile has become a space in which a driver can still perform daily activities besides driving, such as communicating with other people, interacting with electronic devices, and receiving information. In the meantime, different ways of interaction have been explored. Among all the modalities, gestures have been considered as a feasible way for performing in-car secondary tasks because of their intuitiveness. However, few researches have been conducted in terms of subjects' cognitive load. This thesis has examined four gesture interfaces (air swipe, air tap, screen swipe, and screen tap), in terms of their effects on drivers' driving performance, secondary task performance, perceived cognitive load, and eye glance behavior. The result demonstrated that air gestures are generally slower than screen gestures with regard to secondary performance. Screen swipe gesture requires the lowest cognitive load while air swipe and screen tap gesture remain the same. Subjects in this study tend to prefer screen swipe gesture the most while prefer air tap gesture the least. However, there is no significant difference between air swipe and screen tap gesture. Although air tap gesture and screen tap gesture generated the largest amount of dwell times, no variance among the four gesture interfaces in driving performance has been found. The result indicated that even though air gestures are not limited by space, screen swipe in this study still seemed to be the most ideal way for performing in-car secondary task of music selection.

Human error taxonomies have been implemented in numerous safety critical industries. These taxonomies have provided invaluable insight into understanding the underlying causes of human error; however, their utility for actually predicting future errors remains in question. A need has been identified for another approach to supplement what we can extrapolate from taxonomies and better predict human error. Task network modeling is a promising approach to human error prediction that had yet to be empirically evaluated. This study tested a task network modeling approach to predicting human error in the context of automotive assembly. The task network modeling architecture was expanded to include a set of predictors from the human error literature, and used to model part of an operational automotive assembly plant. This manuscript contains three studies. Study 1 tested separate task network models for two different target areas of an active automotive assembly line. Study 2 tested the validity of predictions made by the models from Study 1, both within and across samples. Study 3 tested predictions across both models on a larger sample of vehicles. The expanded architecture accounted for 21.9% to 36.5% of the variance in human error and identified 12 explanatory variables that significantly predicted the occurrence of human error. Model outputs were used to compute prediction equations that were tested using binary logistic regression and then cross-validated twice using both split-half and cross-sample validation. The predictors of Time Pressure, Visual Workload, Auditory Workload, Cognitive Workload, Psychomotor Workload, Task Frequency, Information Flow, Teamwork, and Equipment Feedback were significant predictors of human error in all three models that were tested. The variables of Information Presentation and Task Dependency varied in significance across samples, but both were significant in two out of the three models. The variables of Shift and Hour into Shift were never significant in any of the three models. The variables that were greatly stable across studies were all related to the tasks being performed by each worker at each station. The variables related to the timing of errors, on the other hand, were never significant. The results indicate that an expanded task network architecture is a great tool for predicting the situations and circumstances in which human errors will occur, but not the timing of when they will occur. Nevertheless, task network modeling demonstrated to provide useful, valid, and accurate predictions of human error and should continue to be developed as an error prediction tool.

This thesis is a systematic investigation of preparatory reorienting of task-relevant spatial attention. Task switching experiments typically report a performance overhead when the current task is different to that performed on the previous trial relative to when the task repeats. This ‘switch cost’ tends to reduce as participants are given more time to prepare (consistent with an active reconfiguration process) but a ‘residual’ switch cost usually remains even at very long preparation intervals (often interpreted as evidence of carryover of response selection parameters from the previous trial which are immune to preparation). Although attentional selection of perceptual attributes is often considered to be part of task-set and is included in some models of task-set control, little research has investigated the dynamics of this component in detail. Over a series of seven experiments in which tasks were consistently mapped to screen locations, eye-tracking was used to systematically investigate task-relevant spatial selection of perceptual attributes during the preparation interval and early after stimulus onset. Experiment 1 revealed a switch-induced delay in appropriate attention orientation and a measure of ‘attentional inertia’ which could not be explained by task-independent re-orienting to locations or low-level oculomotor phenomena but were markers of task-relevant spatial selection. Experiment 2 provided a sensitive measure of both of these attentional handicaps and demonstrated that they both contribute to the switch cost (including its residual component). Although attentional inertia reduced with preparation, both handicaps were present at the longest preparation intervals. The constancy of the delay in attending to the relevant attribute reflects the effort to re-allocate attention, rather than peculiarities of spatial orienting when the cue and stimulus are presented near-simultaneously on trials with short cue-stimulus intervals. The presence of attentional inertia in blocks with long preparation intervals suggested some component of inertia immune to preparation (though see Experiments 5 and 6 below). Experiments 3 and 4 investigated the extent to which attentional selection can be decoupled from other task-set components. Cues which explicitly provided location information reduced (or eliminated) the attentional effects found in Experiment 2 indicating that attentional selection can be decoupled from other task-set components. However, Experiment 3 found that the ‘natural’ state is for attentional selection to be coupled at least to a degree (and accessed via) task-set. Experiment 5 combined eye-tracking with ERPs to investigate the relative order of attentional selection and reconfiguration of other task-set components. A well-documented ERP marker of task-set preparation always followed onset of the first fixation on the currently relevant stimulus element indicating that (at least some) task-set components are reconfigured in a serial order with spatial selection preceding other components (e.g., loading of S-R rules or other parameters into working memory). Experiments 6 and 7 investigated the nature of attentional inertia. In Experiment 6 participants were given ultimate control over the duration of the preparation interval which eliminated attentional inertia (at least as indexed by preferential fixation of the previously relevant element on switch trials). In Experiment 7 the stimulus comprised three items which were from perceptually distinct classes (digits, letters, objects) to investigate whether the presence of task-specific features would elicit extra attentional inertia and whether early spatial selection was effective enough to block the processing of task-irrelevant features once the stimulus was presented. Although there was some evidence that the previously relevant stimulus element ‘captured’ attention, this tendency was modest in the fixations and absent in performance measures (response congruence effects).