Millisecond timing on the IBM PC/XT/AT and PS/2: A review of the options and corrections for the Graves and Bradley algorithm

Eleven methods of obtaining millisecond timing on the IBM microcomputer family are briefly reviewed. In our view, the approach recommended by Smith and Puckett (1984) has the fewest limitations, but it must be modified to prevent rare, yet unacceptable, errors. The modified algorithm has been presented for Turbo Pascal, C, and in the present paper, for BASIC and QuickBASIC.     

Millisecond accuracy video display using OpenGL under Linux

To measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this may be done within X Windows using the OpenGL rendering system. A test of this system is reported that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively large errors in measuring the display time.     

Experimental RunTime System: Software for developing and running reaction time experiments on IBM-compatible PCs

The Experimental RunTime System (ERTS) is a recent addition to the small collection of commercial software packages available for writing and running reaction time experiments on IBM-compatible PCs. Experiments are written using any text editor and a relatively small set of ERTS commands. Millisecond timing is provided by a software timer with no additional hardware requirements. All displays are in high-resolution VGA graphics. The Creative Labs Soundblaster card is supported in 16-bit mode, but is not required for simple tone generation. Voice-key support is available via the Soundblaster card. Keyboard, mouse, and external keys may be used as reaction keys, and the mouse or a joystick may be used as a tracking device. The stimulus-centered design and powerful display control commands of ERTS make it appropriate for developing a wide range of trial-based experiments.     

Millisecond interval timer and auditory reaction time programs for the IBM PC

Many types of behavioral research require the determination of elapsed time, for example to establish interstimulus intervals and to measure reaction time. The use of an IBM PC for on-line control of such applications is limited by the poor timing resolution ordinarily available. The IBM BIOS time information that is used for the BASIC TIMER function can result in interval timing errors as great as 110 msec. A machine language subroutine is described that can provide 1-msec accuracy. A BASIC program is also described that employs this subroutine to measure auditory reaction time.     

The effect of alcohol administration on human timing: a comparison of prospective timing, retrospective timing and passage of time judgements

Previous research suggests that human timing may be affected by alcohol administration. The current study aimed to expand on previous research by examining the effect of alcohol on prospective timing, retrospective timing and passage of time judgements. A blind between-subjects design was employed in which participants were either administered 0 g of alcohol per kilogramme of body weight (placebo), 0.4 g/kg (low dose) or 0.6 g/kg (high dose). Participants completed four types of temporal task; verbal estimation and temporal generalisation, a retrospective timing task and a passage of time judgement task. A high dose of alcohol resulted in overestimations of duration relative to the low dose and placebo group in the verbal estimation task. A high dose of alcohol was also associated with time passing more quickly than normal. Alcohol had no effect on retrospective judgements. The results suggest that a high dose of alcohol increases internal clock speed leading to over-estimations of duration on prospective timing tasks, and the sensation of time passing more quickly than normal. The absence of an effect of alcohol on retrospective timing supports the suggestion that retrospective judgements are not based on the output of an internal clock.     

CATECHOLLISION: A game to teach catecholamine synthesis for IBM PCs and compatibles

CATECHOLLISION is an arcade-style computer game that teaches catecholamine synthesis. Tyrosine and the enzymes involved in the synthesis fall from the top of the screen. The player must combine them to produce DOPA and the catecholamines. An accumulation of unused chemicals ends the game. The game includes features such as music and sound effects, several levels of difficulty, a hint option for beginning students, and saved high scores.     

Tachistoscopic timing on the TRS-80

A hardware/software system is described that enables the TRS-80 Model I microcomputer to be used as a tachistoscope. The system synchronizes stimulus presentation with the 16.7-msec scanning rate of the cathode-ray tube. Hardware and software configurations for reaction timing and stimulus presentation are presented and discussed.     

Utterance timing and childhood stuttering

Articulatory speaking rate and response time latency are believed by many to be important factors in determining whether stuttering will occur in a given utterance. Currently, however, there is little empirical evidence to suggest that these measures of utterance timing are directly related to stuttering. This study examined the relationship between articulatory speaking rate and response time latency in the conversational speech of 12 boys who stutter (mean age = 55.2 months; SD = 8.8 months) who participated in 30-min conversational interactions with their mothers. Discriminant function analyses were conducted on 75 utterances drawn from each child's speech sample to determine if the articulatory speaking rate or response time latency of a specific utterance was related to the likelihood that the child would stutter on that utterance. No significant relationships between these measures of utterance timing and stuttering were found for any of the 12 subjects, and there were no significant relationships between these two measures of utterance timing. Findings do not provide support for many current theories of stuttering and suggest that the role of these measures of utterance timing in predicting the occurrence of stuttering in conversational speech in these theories may need to be reexamined.     

Being there on time: Reinforcer effects on timing and locating

In research on timing, reinforcers often are assumed to influence discrimination of elapsed time. We asked whether changes in choice used to measure timing arise because of joint control by elapsed time and reinforcers, rather than from the direct modification of control by elapsed time by reinforcers. Pigeons worked on a concurrent-choice task in which 1 response was 9 times more likely to produce a reinforcer, reversing between locations when 19 s had elapsed since the marker event. Across conditions, we manipulated the percentage of reinforcers arranged before the probability reversal from 5 to 95%. These changes in reinforcer percentages altered control by location-based elements of the contingency, but not by time-based elements. Choice was well described by a model that assumes that control by the contingency is weakened by generalization across the time and location of reinforcers, and that these generalizations become more likely at later times since a marker. These findings add to a growing body of research that suggests that reinforcers share the same function as other environmental events in determining how the environment controls behavior.     

Motor timing deficits in community and clinical boys with hyperactive behavior: the effect of methylphenidate on motor timing

In a previous paper we showed that community children with hyperactive behavior were more inconsistent than controls in the temporal organization of their motor output. In this study we investigated: (1) various aspects of motor timing processes in 13 clinically diagnosed boys with attention deficit hyperactivity disorder (ADHD) who were compared to 11 community boys with hyperactive behavior and to a control group and (2) the effect of methylphenidate on the motor timing processes in the clinical group with ADHD in a double blind, cross-over, medication-placebo design, including 4 weeks of medication. The clinical group with ADHD, like the community group with hyperactivity, showed greater variability in sensorimotor synchronization and in sensorimotor anticipation relative to controls. The clinical group was also impaired in time perception, which was spared in the community group with hyperactivity. The persistent, but not the acute dose, of methylphenidate reduced the variability of sensorimotor synchronization and anticipation, but had no effect on time perception. This study shows that motor timing functions are impaired in both clinical and community children with hyperactivity. It is the first study to show the effectiveness of persistent administration of methylphenidate on deficits in motor timing in ADHD children and extends the use of methylphenidate from the domain of attentional and inhibitory functions to the domain of executive motor timing.     

An inexpensive 1-millisecond experiment control interface for IBM PCs and its user-friendly control language

An inexpensive, professionally manufactured, digital I/O experiment control interface for any PC-compatible computer is described. It plugs into a standard printer port and provides 1-msec accuracy for up to 4 inputs and 22 outputs. It also allows experiment control procedures to be written in an easy-to-learn, easy-to-use Experiment Control language (ECBASIC). In addition to many instructions specifically designed to simplify behavioral research, ECBASIC provides for transparent collection and storage of event logs.     

Implementing communication between Windows PCs and test equipment using RS-232 and Borland C+ + Builder

Modern experiments in the behavioral sciences frequently employ several items of electronic equipment such as computers, monitoring devices, stimulus presentation equipment, and response collection systems. In many cases it would be advantageous for these items to communicate directly with each other. Such communication may facilitate greater automation of experiments (i.e., reduced experimenter influences during the experiment), more precise experiment control (i.e., superior timing and synchronization capabilities of electronic devices), and greater accuracy of data collection (i.e., reduced ambiguity of participant responses). Many electronic experiment devices already provide external interfacesthrough which communication with other devices can be implemented. The most common is based on the RS-232 protocol, which is also found in all standard PCs. Therefore, Microsoft Windows based computers can be programmed to control experiments by communicating directly with electronic experiment devices. We show how to implement this RS-232 interconnection between devices and a Windows PC using currently available software tools.     

Nonballistic coincident timing

A nonballistic coincident timing task was used to assess to what extent retarded subjects could use spatial and temporal information to plan their movements. Subjects did not just respond to events but appeared able to modify/plan their responses, given sufficient time.     

The effect of age on relative timing variability and transfer

The purpose of this study was to investigate potential qualitative differences in relative timing across age both within and across speed conditions. Forty right-handed males performed 48 trials of a five-component coincident-timing task at one speed and then 16 more at a different speed. The independent variables were age (5-7, 8-10, 11-13 years, and adult), speed (slow and fast), and block order (training and transfer). The results indicated that within-speed relative timing consistency improved with increasing age for movement-time and pause-time components, while across-speed transfer improved with age only for pause time. movement velocity emerged as a more stable timing parameter than movement time across speeds for all groups. The last movement-time component correlated highly with the total response times, suggesting that coincident-timing accuracy was controlled to a large degree by a final, fine-tuning correction. These results imply that developmental deficits in relative timing increase the attention demands of a given task, thereby reducing a child's capacity to concurrently control his movements and monitor events in the environment.     

Neuropsychology of timing and time perception

Interval timing in the range of milliseconds to minutes is affected in a variety of neurological and psychiatric populations involving disruption of the frontal cortex, hippocampus, basal ganglia, and cerebellum. Our understanding of these distortions in timing and time perception are aided by the analysis of the sources of variance attributable to clock, memory, decision, and motor-control processes. The conclusion is that the representation of time depends on the integration of multiple neural systems that can be fruitfully studied in selected patient populations.