PROCODER: A professional tape control,coding, and analysis system for behavioral research using videotape

PROCODER is a software system for observing and coding events that have been recorded on videotape. The system uses a personal-computer-based tape controller to control a VHS tape while observations are recorded. Frequencies of events, durations of events, and calculations of inter-observer agreement of events or intervals are included. Data can be output in ASCII format for use with other statistical programs. A sample study in which the system is used is described as well.     

Analyzing sequential relations in observational data: A practical guide

Many observational systems in basic and applied research produce a record of sequences of events over time. Within such observational systems, important information may be found in the frequency of the transitions between events that does not emerge in the typical researcher's focus on absolute event frequency. Indeed, if many behaviors are controlled by closely adjacent preceding events, then substantial prediction and control can be obtained through knowledge and manipulation of causal event transitions. A method for analyzing and testing sequential dependencies between events is proposed as part of an integrated package of computer-based data entry, storage, and analysis procedures. The mathematical portion of these techniques is based on the statistic, kappa,which is applicable to determining whether particular transitions among events differ from chance and whether particular transitions differ significantly across groups of subjects. Low-cost hardware and software to implement the proposed procedures are described.This work has been supported by Grant 1 RO1 HD19245-01A1 from the National Institute of Child Health and Human Development to the two senior authors and by grants of equipment from Commodore Computers, Inc., Koala Corporation, and NEC Telephones, Inc.     

A satellite system for controlling real-time experiments

In this paper, we describe a computer system for controlling real-time psychology experiments. We begin by considering the kinds of experiments that are performed in our laboratory and examining the hardware and software requirements of these experiments. We then review various systems along a continuum ranging from general-purpose timesharing systems to stand-alone dedicated processors. The capabilities of these systems are described in comparison with our requirements. The features of the PARASITE-FS system are then described. This host-satellite system includes a local file system and monitor program, real-time device drivers with flexible interrupt processing capabilities, user-level routines for controlling the real-time devices, and a package for controlling the timing of experimental events.     

A simple system for monitoring the timing of infant gaze to stimuli at specific locations

A system for monitoring the timing of infant gazes to specific locations is described. Infants sit on a parent’s lap in a dark room and observe videotaped stimuli presented on one of four monitors. Infrared (IR) light sources provide illumination for an IR-sensitive video camera and are positioned so that the infant’s direction of gaze can be readily apprehended on the basis of the reflections of the IR light sources relative to the infant’s pupil. The parent monitors the infant’s eyes through a headmounted display and keeps the infant in view of the video camera. Direction and timing of gaze shifts can be coded from frame-by-frame inspection of the videotape. We demonstrate that this coding is relatively accurate and that the present system provides some advantages over coding gaze direction on the basis of an unembellished video recording.     

A vocal response time system for use with sentence verification tasks

A software system for the reliable detection of vocal response onset is described. The system was designed specifically for the measurement of vocal response times to speech stimuli presented aurally in a sound field in the presence of some background noise. The response time extraction method described here is robust to masking noise and extraneous sounds that may be included in the subject’s recorded response. In addition, the response words do not have to be limited to a small set because the system is able to differentiate the onset of any speech sounds, including low-energy fricatives. The method described here may be implemented with any computer sound system because it relies only on the sound conversion clock for timing accuracy and uses postprocessing of the signal after acquisition for response extraction. The response time extraction technique as currently implemented does not recognize subject’s responses but could be incorporated into an automatic speech recognition system.     

DataVision: A computer-based system for generating and reading digital information accompanying video images on videotape

An Apple IIe-based system is described that generates both machine-readable and human-readable numbers for recording with visual information on videotape. Hardware and software components of the encoding system are detailed. An automatic decoding system that reads the numbers from videotape into computer memory is also described. Current applications of the system are briefly discussed.     

Instrumentation and software report: Computer-assisted coding of videotape material

The coding system described was originally devised to facilitate the analysis of mother-infant interaction. Our aims were to provide accurate measures of the duration of different activities, to enable identification of particular actions in order to carry out sequential analyses, and to allow systematic assessment and improvement of reliability. At the time recording began, there appeared to be no readily available systems which achieved all of these aims. The system described here enables coded videotape material to be examined with the assistance of a computer. This is implemented through two subsystems, those of record and playback. In the playback subsystem the behaviour units identified by a coder are mapped on to this record. This results in a protocol of behaviour on a highly accurate time base.     

Instrumentation and software report: Computer-assisted coding of videotape material

The coding system described was originally devised to facilitate the analysis of mother-infant interaction. Our aims were to provide accurate measures of the duration of different activities, to enable identification of particular actions in order to carry out sequential analyses, and to allow systematic assessment and improvement of reliability. At the time recording began, there appeared to be no readily available systems which achieved all of these aims. The system described here enables coded videotape material to be examined with the assistance of a computer. This is implemented through two subsystems, those of record and playback. In the playback subsystem the behaviour units identified by a coder are mapped on to this record. This results in a protocol of behaviour on a highly accurate time base.     

A microcomputer-based software package for eye monitoring research

A software package is described that collects and reduces eye behavior (eye position and pupil size) data using an IBM-compatible personal computer. Written in the C language for speed and portability, the package includes several unique features: data can be collected simultaneously from other sources (e.g., EEG, EMG), logically defined events can be detected in real time on any data channel, and either of two types of data matrix can be produced. Data reduction algorithms and data structures are described.     

Cartesian analysis: A computer-video interface for measuring motion without physical contact

In this paper, we describe a computer-video interface capable of measuring videotaped motion without physical contact. It constructs imaginaryx-, y-, z-coordinates around a moving object by juxtaposing front and side views on one video record. A special effects generator (SEG) superimposes this two-part image onto the microcomputer’s graphic output. The user watches the SEG’s output and traces the motion of interest in real-time with a computer-generated cursor, a process that assesses the onset time, termination time, duration, linear displacement (i.e., length), and velocity of each traced movement. Reliability coefficients between two independent users were .99 for onset time, .85 for duration, .89 for displacement, and .90 for velocity. In 80 gestures, the correlation between estimated displacement and measured displacement was .73; the correlation between estimated duration (determined from frame-by-frame inspection of the videotape) and measured duration was .80. Twenty-five measurements of displacement for a motorized target traveling 75.4 in. differed from the true value by | .06 |, | .06 |, and | .30 | in. for thex, y, andz dimensions, respectively.     

CowLog: Open-source software for coding behaviors from digital video

We have developed CowLog, which is open-source software for recording behaviors from digital video and is easy to use and modify. CowLog tracks the time code from digital video files. The program is suitable for coding any digital video, but the authors have used it in animal research. The program has two main windows: a coding window, which is a graphical user interface used for choosing video files and defining output files that also has buttons for scoring behaviors, and a video window, which displays the video used for coding. The windows can be used in separate displays. The user types the key codes for the predefined behavioral categories, and CowLog transcribes their timing from the video time code to a data file. CowLog comes with an additional feature, an R package called Animal, for elementary analyses of the data files. With the analysis package, the user can calculate the frequencies, bout durations, and total durations of the coded behaviors and produce summary plots from the data.     

A simple LSI-11 system for real-time control,interevent time storage,and data analysis

A simple laboratory computer system based on a Digital Equipment Corporation LSI-11, floppy disk, DRV11 parallel input-output board, and the RT-11 operating system is described. Interface to experimental devices is provided through a lab-built relay driver and relay closure sensing interface. An extensive high-level software package provides an easy-to-use control language (e.g., stimuli can be controlled with a simple “TURN ON” or “TURN OFF” instruction) and easy-to-use FORTRAN subroutines for data exploration (e.g., “IFIND” searches a data file for a particular event). The control software automatically generates, codes, and stores a complete log of every input and output event and its time of occurrence in each of five simultaneously running experiments. This provides the capability to reanalyze data in light of hypotheses not available when the experiment was designed. The FORTRAN subroutine library for data exploration provides a conditional and iterative search facility to sift out events or sets of events from the data file for analysis. Standard FORTRAN statements perform arithmetic operations on the resulting data.     

A semiautomatic method for adding behavioral data to videotape records in combination with the Noldus Observer system

The Observer 3.0 (Noldus, 1991) was used as the base for a time-saving fine analysis of animal behavior. A PC controlled a shuttlebox and a shuttlebox control unit. Learning behavior was recorded on videotapes by an S-VHS camcorder with vertical interval time code (VITC), which was used to generate an observational data file (ODF). The observational system was enhanced by automatically recorded status signals from the PC as event markers on the soundtrack of the videotape. These signals were used to subdivide a training session into numbered trials during generation of the ODF. They were later used for a PC-aided fine analysis of behavioral events, such as attention responses (AR) and orienting responses (OR) during shuttlebox learning. In this way, a large number of both automatically inserted PC event markers and manually inserted, key-defined behavioral events were registered and analyzed effectively in a semiautomatic fashion. The system is illustrated with an analysis of shuttlebox avoidance data from gerbils (Meriones unguiculatus).     

Infants' Visual Expectations and the Processing of Time

Visual events are defined by a number of dimensions—their location in space, content (color, shape, etc.), and time tags (onset, duration, etc.). The role of time in infants' performance in the Visual Expectation Paradigm (VExP) was studied to evaluate whether infants encode in their expectation representation the timing of events in addition to their spatial location and content. In Experiment 1, 3-month-olds produced more anticipations in a temporally predictable condition than in an unpredictable condition, suggesting that their expectations included a timing component. No evidence was found, however, that infants processed events' precise timing, but they instead appeared to process events' average temporal flow rate. This was supported in Experiment 2, in which infants trained with a shorter flow rate exhibited an increase in anticipations after being shifted to a longer flow rate, whereas those trained with a longer flow rate exhibited a decrease when shifted to a shorter flow rate. These findings indicate 3-month-olds encode in their expectation representation the average temporal flow rate rather than the precise timing of events. The findings also suggest that the VExP may be useful for exploring infants' ability to make time estimates that involve action.     

Time-stamping computer events to report .1-msec accuracy of events in the Micro Experimental Laboratory

A critical problem in most real-time programming tasks is the verification that timing of the presented displays and recorded events occur at the expected times. It is often difficult for psychologists to verify critical timing because of the lack of costly specialized tools and technicians to measure events with millisecond accuracy. Algorithms utilized in a new Time Audit mechanism, added to the Micro Experimental Laboratory, are described. This new mechanism involves the recording and time stamping of all input and output events with 0.1-msec accuracy. This allows the experimenter to determine the initiation, duration, and termination of each event and also makes it possible to relate these events to the synchronization of the screen refresh cycle. A customized user interface provides a time log and event-tracing feature that enables nonprogrammers to determine the duration of command execution to the .1-msec level, allowing rapid, precise assessment of program execution. The resulting time log provides a detailed specification of the experimental events for debugging and a permanent record of the experimental procedure.     

Laboratory behavioral measures of impulsivity

Previous research and theory have conceptualized impulsivity as a multifaceted construct that requires multiple modes of measurement for accurate assessment. This article describes a software package that includes four paradigms for measuring multiple and unique aspects of impulsivity. Specifically, four tasks are described: (1) the two choice impulsivity paradigm, (2) the single key impulsivity paradigm, (3) the GoStop impulsivity paradigm, and (4) the time paradigm. These tasks measure processes related to the capacity to tolerate delay for reward, to inhibit an already initiated response, and to estimate the passage of time. These processes have been found to be important to the understanding of impulsive behaviors. The programs are flexible and allow the experimenter to manipulate a number of parameters related to delay-reward contingencies, timing, performance feedback/payment, and data output variables. Manipulation of these parameters makes the paradigms scalable to a wide range of ability levels and appropriate for samples ranging from children to adults. The four paradigms in this software package are available at no cost and can be obtained by contacting the corresponding author.     

RTbox: A device for highly accurate response time measurements

Although computer keyboards and mice are frequently used in measuring response times (RTs), the accuracy of these measurements is quite low. Specialized RT collection devices must be used to obtain more accurate measurements. However, all the existing devices have some shortcomings. We have developed and implemented a new, commercially available device, the RTbox, for highly accurate RT measurements. The RTbox has its own microprocessor and high-resolution clock. It can record the identities and timing of button events with high accuracy, unaffected by potential timing uncertainty or biases during data transmission and processing in the host computer. It stores button events until the host computer chooses to retrieve them. The asynchronous storage greatly simplifies the design of user programs. The RTbox can also receive and record external signals as triggers and can measure RTs with respect to external events. The internal clock of the RTbox can be synchronized with the computer clock, so the device can be used without external triggers. A simple USB connection is sufficient to integrate the RTbox with any standard computer and operating system.     

Experimental control programs for the UNIX operating system

The software described runs on Version 7 UNIX, although most run on earlier versions. Using the curses package requires two program libraries from the Fourth Berkeley Distribution (CURSES and TERMLIB). Using any of the functions requires knowledge of programming, preferably in C (Kernighan & Richie, 1978), but the sample experimental control program is usable by nonprogrammers. Because no special hardware is assumed, the resolution of timed presentations and reaction time recordings may not be accurate enough for some purposes. Functions for stimulus presentation have a resolution of 1 sec, and those for timing responses are accurate to about 17 msec.     

Recoding low-level simulator data into a record of meaningful task performance: The integrated task modeling environment (ITME)

The Integrated Task Modeling Environment (ITME) is a user-friendly software tool that has been developed to automatically recode low-level data into an empirical record of meaningful task performance. The present research investigated and validated the performance of the ITME software package by conducting complex simulation missions and comparing the task analyses produced by ITME with taskanalyses produced by experienced video analysts. A very high interrater reliability (> or = .94) existed between experienced video analysts and the ITME for the task analyses produced for each mission. The mean session time:analysis time ratio was 1:24 using video analysis techniques and 1:5 using the ITME. It was concluded that the ITME produced task analyses that were as reliable as those produced by experienced video analysts, and significantly reduced the time cost associated with these analyses.