Mental workload and visual impairment: differences between pupil, blink, and subjective rating

This research has two aims: (a) To study the concurrent validity of three measures of mental workload, NASA TLX rating scale, pupil dilation and blink rate, testing the hypothesis that they will provide convergent results using a single-task, and dissociative results for dual-task; and (b) To analyse their capability to predict visual search impairment. These three measures were analyzed in the same cognitive tasks in single-task and dual-task (cognitive task and visual search) conditions in a within-subjects experiment with twenty-nine participants. Mental workload measures showed concurrent validity under single-task condition, but a complex pattern of results arose in the dual-task condition: it is suggested that NASA TLX would be a subjective addition of the rating of each task; pupil dilation would measure the average arousal underlying the cognitive tasks; and the blink rate would produce opposite effects: whereas mental workload of cognitive tasks would increase blink rate, visual demand would inhibit it. All three measures were good predictors of visual impairment. The soundness of these measures is discussed with regard to the applied field of driving and other activities.     

A computerized slot machine simulation to investigate the variables involved in gambling behavior

The present paper describes a computerized slot machine simulation designed to examine many of the potential variables involved in gambling behavior. This program was created in Visual Basic Version 6.0 and is designed to run on any Windows 95 or higher equipped computer. The program allows for experimenter manipulation of probabilities of payoffs, visual display of potential winning symbols, exact sequences of wins and losses, as well as pose run time questions to the subject on prespecified trials. The program records data on a trial-bytrial basis to a text file for easy importation into many data analysis and statistical programs. Conceptual and experimental questions that may be addressed with the described program are also discussed.     

The effect of gender and time-of-day on time perception and mental workload

Two experiments are reported which investigated how subject gender and time-of-day influenced the estimation of duration and the perception of task-related mental workload. In the first experiment, 24 subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800h, 1200h, 1600h, and 2000h, respectively. In the second experiment, 12 different subjects performed an unfilled time estimation task in similar conditions at 0900h, 1400h, and 1900h. At the termination of all experimental sessions, participants completed the NASA Task Load Index workload assessment questionnaire as a measure of perceived mental workload. Results indicated that physiological response, reflected in body temperature change, followed an expected pattern of sequential increase with time-of-day. However, estimates of duration and the perception of mental workload showed no significant effects for time-of-day. In each of the experiments there were significant differences in time estimation and mental workload response contingent on the gender of the participant. These results are interpreted in light of the previous positive findings for circadian fluctuation in performance efficiency and the equivocal findings of a gender difference in time estimation. A unifying account of these collective results is given based on gender by time-of-day interactional effects. An earlier version of this paper was presented at the 32nd Annual Meeting of the Human Factors Society, Anaheim, CA, October, 1988.     

The effect of gender and time-of-day on time perception and mental workload

Two experiments are reported which investigated how subject gender and time-of-day influenced the estimation of duration and the perception of task-related mental workload. In the first experiment, 24 subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800h, 1200h, 1600h, and 2000h, respectively. In the second experiment, 12 different subjects performed an unfilled time estimation task in similar conditions at 0900h, 1400h, and 1900h. At the termination of all experimental sessions, participants completed the NASA Task Load Index workload assessment questionnaire as a measure of perceived mental workload. Results indicated that physiological response, reflected in body temperature change, followed an expected pattern of sequential increase with time-of-day. However, estimates of duration and the perception of mental workload showed no significant effects for time-of-day. In each of the experiments there were significant differences in time estimation and mental workload response contingent on the gender of the participant. These results are interpreted in light of the previous positive findings for circadian fluctuation in performance efficiency and the equivocal findings of a gender difference in time estimation. A unifying account of these collective results is given based on gender by time-of-day interactional effects. An earlier version of this paper was presented at the 32nd Annual Meeting of the Human Factors Society, Anaheim, CA, October, 1988.     

Computing interrater reliability on the Apple Macintosh computer

A program is described for computing interrater reliability by averaging, for each rater, the correlations between one rater’s ratings and every other rater’s ratings. For situations in which raters rate more than one ratee, raters’ reliabilities can be computed for either each item or each ratee. The program reads data from a text file and puts the reliability coefficients in a text file. The standard Macintosh interface is implemented. The Quick-BASIC program is distributed both as a listing and in compiled form; it can be run with advantage with math coprocessors.     

Object relocation: a program for setting up, running, and analyzing experiments on memory for object locations

Object Relocation is a computer program for Windows 95, with which experiments on spatial memory for object locations can be designed, run, and analyzed. Because of its clear graphical user interface, no long and complex command syntax is needed. Basically, a stimulus consists of a frame that contains a chosen number of locations (i.e., the actual spatial layout) to which objects can be assigned. When the experiment is run, these stimuli are presented to the subject for a variable period of time. Subsequently (either with or without a delay), the objects are presented in a row above the frame and have to be relocated to the correct positions. Finally, the raw data can be analyzed efficiently, using various error scores, and an SPSS-ready output file can be produced. Object Relocation is a very flexible program: New objects and positions can easily be added, and various options for presentation and relocation are present.     

The Observer: A software system for collection and analysis of observational data

The Observer is a general-purpose software package for event recording and data analysis in behavioral research. It allows any IBM-type personal computer to serve as an event recorder. In addition, The Observer can generate dedicated event-recording programs for several types of non-IBM-compatible portable and hand-held computers and transfer files between the PC and such computers. The user specifies options through menus. The configuration can be either used directly for event recording on the PC or passed on to a program generator that creates a program to collect data on a hand-held computer. Observational data from either type of computer can be analyzed by the program. Event-recording configurations can be tailored to many different experimental designs. Keys can be designated as events, and modifiers can be used to indicate the limits of an event. The program allows grouping of events in classes and distinction between mutually exclusive versus nonexclusive events and duration events versus frequency events. Timing of events is accurate to 0.1 sec. An on-line electronic notepad permits notes to be made during an observation session. The program also includes on-line error correction. User comments as well as independent variables can be stored together with the observational data. During data analysis, the user can select the level of analysis and the type of output file. The Observer calculates frequency of occurrence and duration for classes of events, individual events, or combinations of events. For analysis of concurrence, one can select the number of nesting levels and the order of nesting. Output can be generated in the form of sorted event sequence files, text report files, and tabular ASCII files. The results can be exported to spreadsheet and statistical programs.     

Empirical distributions of correlations as a tool for scale reduction

A Visual Basic program for generating a distribution of correlations as a tool for scale reduction is presented; the program is available free from the author and runs on IBM-compatible personal computers under the Windows 95/98/NT operating systems. The program generates a list of item combinations and correlations between the unit weighted sum of the items and a criterion score. The list can be used to locate item combinations that have high correlations with the original full-length test. An example application is presented to illustrate the use of the program. The compiled program and its source code can be downloaded from http://personal.bgsu.edu/~stanton/r_crunch/r_crunch.zip.     

Driving mental workload and performance of ageing drivers

The World Health Organization stated that the global ageing population is increasing rapidly as well as the case of road accidents involving ageing drivers. This study presents the driving mental workload and performance model of ageing drivers in the context of real-time road driving. Twenty paid participants (ten males) with a mean age of 57.8 years old (SD = 2.7) and mean driving experience of 29.6 years (SD = 8.5) took part in driving experiments with three complexity levels of situation: simple situation (SS), moderately complex situation (MCS), and very complex situation (VCS). The subjective ratings using NASA Task Load Index (NASA-TLX), physiological measure using electroencephalogram, number of traffic violations (NTVs), speed variability, and reaction time of peripheral detection task were measured. The driving experiments reveal the following: (1) The subjective workload ratings on mean physical demand score were the highest. (2) The electroencephalogram results show that situation complexity had significant effects on theta relative power and alpha relative power of two channel locations (3) The highest mean NTVs was in VCS. (4) The mean speed variability in the MCS was significantly lower than that of in the SS and VCS. (5) The maximum reaction time was recorded in VCS while the minimum reaction time was recorded in the MCS. The overall driving performance score regression models were developed based on the strong correlation and linear relationship between mental workload and driving performance elements. The models may benefit as a reference for designers, manufacturers, developers, and policymakers in designing better driving environment for ageing drivers by integrating safety and transportation, thus, optimizing and sustaining the driving performance of ageing drivers.     

Eye movement research on the propositional structure of short texts

The present paper describes the application of computer-based programs to the evaluation of eye movements during reading of short texts. These programs operate in background, that is, after an experimental session is completed and the raw data are collected on magnetic tape. The first program reduces the raw data into a sequence of fixation locations and durations, eye movements, and eye blinks. A second program utilizes calibration coordinates and line-of-text information to transform the reduced data into a standard grid format. Fixation order, locations, and durations for each line of text read are output with respect to the line of text. The final program summarizes fixation locations, frequencies, and durations with respect to analyses of the texts into levels within a hierarchy of propositions in the text base (Kintsch, 1974).     

The role of the Big Five personality factors in vigilance performance and workload

Using the five‐factor personality model, the present study explored the influence of personality factors on sustained attention and perceived workload. Ninety‐six college‐aged participants were administered a 12 minute vigilance fast event rate task. Following the vigil, participants were asked to first, rate their perceived workload of the task using the NASA‐TLX, and then second, complete the NEO‐PI‐R personality inventory. Traditional measures of hits, false alarms, and reaction times were examined as well as the signal detection indices of perceptual sensitivity and response bias. Extraversion correlated with false alarms (r = 0.181; eta² = 0.055) and conscientiousness correlated with both false alarms (r = ?0.275, eta² = 0.097) and perceptual sensitivity (r = 0.227, eta² = 0.052). With regard to perceived workload, neuroticism was related to perceived frustration (r = 0.238, eta² = 0.057). The findings are discussed in terms of theoretical implications, impact of task parameters, and practical applications. Copyright © 2002 John Wiley & Sons, Ltd.     

视觉追踪作业心理负荷的多变量评估研究

敏感性是心理负荷测量技术可靠性的基本要求。该研究利用主任务绩效、次任务绩效、主观“加权负荷”评定和心率变异变化率四项指标,在计算机模拟情境下对视觉追踪作业心理负荷进行多变量评估实验。结果发现,以上述四项指标为基础建立的“综合加权评估指数”是一项较有效的评估指标,其敏感性远高于任何单独的评定。     

A theoretical distribution for mental test scores

The negative hypergeometric distribution of raw scores on mental tests is derived from certain assumptions relating to test theory. This result is checked empirically in a number of examples. Further derivations lead to the bivariate distribution of parallel tests which is also verified with actual data. The bivariate distribution of raw score and true score is also derived from a further assumption. This distribution is used to set confidence limits for true scores for persons with a given raw score.This work was supported in part by contract Nonr-2752(00) between the Office of Naval Research and Educational Testing Service. Reproduction in whole or in part for any purpose of the United States Government is permitted.     

Graze: A program to analyze recordings of the jaw movements of ruminants

Graze is a user friendly, Microsoft Windows 95/NT program for analyzing jaw movement recordings taken with the IGER Behavior Recorder. The program displays a plot of the jaw movement amplitude (vertical axis) against time (horizontal axis). Individual jaw movements can be automatically identified, using amplitude and frequency criteria specified by the user. Bouts of jaw movements can then be analyzed and are automatically identified as either grazing or ruminating. Behaviors other than grazing and ruminating (such as drinking or eating supplements) can also be identified and marked by the user. Identified jaw movements and bouts of behavior are superimposed on the jaw data display. Finally, the user can perform a bout analysis, which discriminates between bites and chews during eating and generates a summary file.     

What Am I? Virtual Machines and the Mind/Body Problem

When your word processor or email program is running on your computer, this creates a “virtual machine” that manipulates windows, files, text, etc. What is this virtual machine, and what are the virtual objects it manipulates? Many standard arguments in the philosophy of mind have exact analogues for virtual machines and virtual objects, but we do not want to draw the wild metaphysical conclusions that have sometimes tempted philosophers in the philosophy of mind. A computer file is not made of epiphenomenal ectoplasm. I argue instead that virtual objects are “supervenient objects.” The stereotypical example of supervenient objects is the statue and the lump of clay. To this end I propose a theory of supervenient objects. Then I turn to persons and mental states. I argue that my mental states are virtual states of a cognitive virtual machine implemented on my body, and a person is a supervenient object supervening on this cognitive virtual machine.     

On the "optimal" size for normative samples in neuropsychology: capturing the uncertainty when normative data are used to quantify the standing of a neuropsychological test score.

Bridges and Holler (2007) have provided a useful reminder that normative data are fallible. Unfortunately, however, their paper misleads neuropsychologists as to the nature and extent of the problem. We show that the uncertainty attached to the estimated z score and percentile rank of a given raw score is much larger than they report and that it varies as a function of the extremity of the raw score. Methods for quantifying the uncertainty associated with normative data are described and used to illustrate the issues involved. A computer program is provided that, on entry of a normative sample mean, standard deviation, and sample size, provides point and interval estimates of percentiles and z scores for raw scores referred to these normative data. The methods and program provide neuropsychologists with a means of evaluating the adequacy of existing norms and will be useful for those planning normative studies.     

A mobile computing solution for collecting functional analysis data on a Pocket PC

The present paper provides a task analysis for creating a computerized data system using a Pocket PC and Microsoft Visual Basic. With Visual Basic software and any handheld device running the Windows Moble operating system, this task analysis will allow behavior analysts to program and customize their own functional analysis data-collection system. The program will allow the user to select the type of behavior to be recorded, choose between interval and frequency data collection, and summarize data for graphing and analysis. We also provide suggestions for customizing the data-collection system for idiosyncratic research and clinical needs.