Influence of an intertrial interval on sequential effects related to preparatory period duration for reaction time-task

In reaction time tasks, where the moment of occurrence of the response signal is uncertain, the temporal constraints of preparatory processes imply that subjects distribute their preparation during the preparatory period. The notion of cost of preparation has been proposed to explain the time course of these processes. This experiment was run to determine the effect of the cost of preparation on a serial-RT task and on a RT task where a rest interval of various possible durations (3, 6, or 9 sec.) is introduced. 12 subjects were tested. Data show that the amount spent on preparation during a trial affects the subject's performance during the next trials. But an hypothesis about memory search must also be advanced to explain the effect of the rest interval on the relationship of RT and the current preparatory period.     

Short-term memory for time intervals

The effect of intertrial interval, preset interval, and retention interval on the performance of rats in a time estimation task was described. On each trial a signal was presented for a duration of 2 to 8 sec. Eighteen rats were trained to press one lever (the short response) if the signal was shorter than 4 sec, and another lever (the long response) if the signal was longer than 4 sec. When trials were massed (Experiment 1), the percentage long response was affected by the classification of the previous signal, but not by its actual duration. This suggests that the animals remembered the response made on the previous trial, but not the signal duration. If a response was not permitted on the previous trial (Experiment 2), the duration or classification of the previous signal had no effect on performance. This supports the conclusion from the first experiment and suggests that an animal can reset its internal clock in less than 2 sec. In Experiment 3, the difference limen of the psychophysical function increased with the duration of the retention interval, but the point of subjective equality did not change. This suggests that resetting of the internal clock occurs on a non-time dimension.     

High order sequential effects and the negative gradient of the relationship between simple reaction-time and foreperiod duration.

In a simple RT task with variable interstimuli intervals (ISI), the negative slope of the RT-ISI duration relationship is generally interpreted as an effect of the increasing conditional probability of the response signal (RS). A previous study using 6 different ISIs has shown that the first order sequential effects (SE) contribute, for a part, to this slope. The aim of the present experiment was to investigate, up to the fifth order, the SEs observed when two different ISIs (1.5 and 3.0 sec) are used. The results show that SEs also intervene in the tendency for the Ss to be preferentially prepared when the RS occurs at the end of the long ISIs. They are discussed according to the hypothesis that the role played by these SEs in the negative slope of the RT-ISI relationship is primarily due to the opportunity given the Ss in such an experiment to make two successive preparations.     

Searching short-term memory for linear-positioning movements

To determine whether memory search for movements was serial or parallel, the search processes involved in a short-term motor-memory paradigm were investigated. A linear-positioning task was used to present a series of 1, 2, or 3 movements in a memory set. Upon completion of a memory set, subjects were presented with a search movement. The search movement was either the same length as one of the memory-set movements ("yes" response) or a different length ("no" response). Four subjects completed three consecutive days of testing. On Day 1 RT and movement length were practiced. On Day 2 the subjects were required to search a memory set of movements and respond in the yes condition by lifting the index finger of the left hand. This movement terminated a RT search clock. The same procedures were followed on Day 3, except that a no response was indicated by lifting the index finger. A 2 X 3 X 3 (response X memory set X RT trials) within-subjects analysis yielded nonsignificant main effects and interactions. The results were discussed in relation to verbal memory.     

Stimulus intensity and foreperiod effects in intersensory facilitation

Intersensory facilitation refers to the more rapid reaction time (RT) to a target in one modality and an accessory stimulus in a different modality compared to a RT to the target alone. Prior studies suggest two processes contribute to the phenomenon, termed the preparatory state and energy integration which refer to the action of accessory stimulation in providing forewarning and intensifying the reaction signal, respectively. Experiment I factorially varied foreperiod duration, light (target) intensity and tone (accessory) intensity in a discriminative RT task. The results were that foreperiod (preparatory state) and intensity (energy integration) effects were additive, implying that they affected separate processing stages. Accessory stimulus intensity affected false alarm rate on catch trials. This suggests that energy integration involves a form of response bias (increased likelihood of responding) and not facilitation (more rapid information processing). Experiment II indicated that comparable energy integration effects obtain with tone as target and light as accessory, as well as vice versa. The findings further indicated that RT to a bisensory pairing is more rapid when attention is directed to the more potent member of the pair.     

Set and temporal integration

An experiment was conducted to explore the temporal structure of set formation in a complex reaction time (RT) task. On each trial an instruction [I-event] was given telling Ss whether identity of color or form on a separately presented alternative display (A-event) was the dimension relevant on that trial. The A-event consisted of a pattern of four colored forms. The two forms on one side were matched for color and on the other side for form. S’s task was to depress one of two keys. The correct key was homolateral to the matched relevant dimension. The basic independent variable was the time interval separating the I- and A-events (ISI). At short ISIs, RT wasa linear function oflSI with slope equal to -0.5. RT was independent of the order in which the events occurred at short ISIs, although at longer ISIs (3 sec) RT was longer when the A-event followed the I-event. Also, RT was shorter at short ISIs when color was the relevant dimension rather than form. although this difference disappearedat longer ISIs. The results were discussed in relation to information processing models and previous research dealing with partialadvance information.     

Effect of moderate doses of alcohol on simple auditory reaction time in a vigilance setting

An experiment was performed with 11 voluntary male subjects to test the effects of moderate doses of alcohol on simple auditory RT in a vigilance setting. Subjects were tested during a 30-min. session, during which signals were presented with an average intersignal interval of 3.75 sec. Subjects responded by pressing a microswitch held in the preferred hand. Analysis indicated that absolute means increased as a function of alcohol dose. With time-on-task alcohol produced a faster increase in RT and especially affected the longest RTs. Number of extreme long reactions (blockings) and mean duration of these reactions increased under alcohol and were directly related to time on task; alcohol produced a much faster increase in number of blockings with time on task. Results were discussed in terms of attentional processes and habituation theory. Some practical implications of the results were pointed out.     

Eye-Hand Coordination in Rhythmical Pointing

The authors investigated the relation between hand kinematics and eye movements in 2 variants of a rhythmical Fitts's task in which eye movements were necessary or not necessary. P. M. Fitts's (1954) law held in both conditions with similar slope and marginal differences in hand-kinematic patterns and movement continuity. Movement continuity and eye—hand synchronization were more directly related to movement time than to task index of difficulty. When movement time was decreased to fewer than 350 ms, eye—hand synchronization switched from continuous monitoring to intermittent control. The 1:1 frequency ratio with stable π/6 relative phase changed for 1:3 and 1:5 frequency ratios with less stable phase relations. The authors conclude that eye and hand movements in a rhythmical Fitts's task are dynamically synchronized to produce the best behavioral performance.     

Lengthening fixed preparatory foreperiod durations within a digit magnitude classification task serves mainly to shift distributions of response times upwards

In this study, the effect of lengthening foreperiod duration (i.e. the time between the presentation of a warning signal and a subsequent target stimulus) on choice RTs is examined. The foreperiod durations used were either 2 or 8 s and were fixed within pure blocks of trials. The task was to determine whether a single-digit target stimulus was either smaller or larger than 5 and responses were provided manually. An additive relation between foreperiod duration length and numerical distance from 5 was present in the mean RTs. Subsequent ex-Gaussian analyses of the shapes of the RT distributions indicated that they become shifted upwards as the foreperiod increased with relatively smaller increases in the sizes of their tails. It is argued mainly that the latter finding is incompatible with the strategic time estimation view of the fixed foreperiod duration effect.     

Advance task preparation reduces task error rate in the cuing task-switching paradigm

Advance preparation reduces RT task-switching cost, which is thought to be evidence of preparatory control in the cuing task-switching paradigm. In the present study, we emphasize errors in relation to response speed. In two experiments, we show that (1) task switching increased the rate at which the currently irrelevant task was erroneously executed ("task errors") and (2) advance task preparation reduced the task error rate to that seen in nonswitch trials. The implications of the results to the hypothesis concerning task-specific preparation are discussed.     

Effects of amphetamine and barbiturate in a serial reaction task under paced and self-paced conditions.

Effects of drug conditions (barbiturate, amphetamine, placebo) were investigated in a serial choice RT-task under three pacing conditions: self-paced, paced-fast (approx. 3 signals/sec) and paced-slow (approx. 1 signal/sec). Drug treatment and pacing condition were varied in a factorial design with 9 male Ss. Drugs affected the reaction time but not the error scores. Barbiturate slowed down RT and this effect was most prominent in paced-fast. Amphetamine, on the other hand, speeded up the RT but it had no effect in paced-fast. To account for these differential effects of the two drugs, it was postulated that barbiturate counteracts the arousing effect of time pressure whereas amphetamine speeds up reaction when the task is not arousing. This is consistent with Trumbo and Gaillard (1975) but it contradicts predictions derived from a theory by Broadbent (1971).     

Effect of the length of the runs of repetitions on the simple RT-ISI relationship

In a simple RT task the temporal organization of the preparatory processes during a given trial depends upon the time characteristics of the total experimental situation as well as upon the information gathered during one or more previous trials. The present experiment was run in order to determine whether or not these long and short term effects operate independently or interact. The effects of the preceding ISI durations on the simple RT for an ISI 1 (1.5 s) or an ISI 2 (3.0 s) are analysed in 3 experimental conditions differing in the maximum number of successive repetitions (2, 3 or 7) of trials with the same ISI. The results show that the distribution of the preparatory activity during a given trial depends firstly on the number of successive ISIs of the same duration preceding this trial, and secondly on the maximum number of repetitions. An explanation of the subjects' strategy based upon “cost of preparation” is proposed.     

On the peculiarity of simple reaction time

Two experiments are reported in which high-compatibility reaction time (RT) tasks were performed with, and without, a concurrent secondary task. In both experiments, the secondary task interfered to a greater extent with simple RT than with choice RT. In fact, the effect of adding a secondary task was to eliminate the advantage of simple RT over two-alternative-choice RT. Previous studies of this phenomenon employed a task in which subjects raised a finger when it received tactile stimulation, while engaging in continuous reading aloud. The present experiments show that the effect can be obtained using a different stimulus modality (vision) as well as other responses (vocal) and secondary tasks (shadowing, auditory step-tracking). The paradigm provides a means of isolating preparatory processes that are peculiar to the simple RT task.     

Disruptions of preparatory attention contribute to failures of prospective memory

In two experiments, we examine the efficacy of preparatory attentional processes and intention superiority as explanations of the finding that response time (RT) for prospective memory (PM) cue misses is often faster than that for ongoing activity trials or PM cue hits. RT was faster for prospective misses than for ongoing activity trials, demonstrating an intention superiority effect. RT was also faster for ongoing activity trials preceding prospective misses than for those preceding prospective hits. We interpret this finding as reflecting variation in the efficiency of preparatory attentional processes during task performance, leading to failures of PM when preparatory attentional processes are suboptimal.     

Generalizations and extensions of the precue-utilization effect in rapid reactions.

The method of brief PSIs (precue-to-stimulus intervals) was used in three RT (reaction-time) experiments to explore the generality of the precue-utilization effect in rapid reactions, and to examine two extensions. This effect, which shows the self-contained performance in the choice reaction of the processing operations that culminate in response selection, generalized to a quantitative discrimination and to unequal stimulus-response (SR) frequencies. In the first extension, the reduction in wrong-alternative errors at relatively long PSIs indicated that these errors occur in conjunction with commitment to response actualization. In the second extension, the duration of discrimination-selection was found to be no longer for the less frequent of two SR alternatives. Taken together, these findings indicate that the effect of relative SR frequency, on incidence of errors as well as length of RT, fell on response-actualization processing. This is in accord with a number of previous findings and consonant with effects of RT variables on movement parameters but contrary to cumulative speed-accuracy models.     

The foreperiod effect revisited

This paper explores four factors which could be important in accounting for the discrepant results which have previously been obtained with respect to the effect of foreperiod duration on reaction time (RT). In some studies a clear effect of foreperiod duration on auditory RT has been found, in contrast to a recent finding that foreperiod duration affected visual RT but not auditory RT. By means of two experiments, the effects of practice, time-on-task, reaction task (a-reaction versus selective reaction) and signal intensity were studied. The latter variable appears to be the principal determinant of the discrepant results in that there is an interaction between signal intensity, foreperiod duration and modality. The results fit the hypothesis that signals beyond a given intensity exert an immediate arousing effect which counteracts the foreperiod effect.     

Preparatory Set,Response Complexity,and Reaction Latency

The interaction between preparatory set and response complexity was demonstrated in an experiment investigating the reaction latency of discrete arm movements. Following simple finger-lift reaction-time (RT) trials, subjects performed simple and complex versions of a discrete horizontal arm movement under one of two enforced preparatory set conditions. For the simple task, requiring subjects to attend to the components of the response prior to stimulus presentation (enforced motor set) produced significantly shorter RTs than when concentration was on the stimulus (enforced sensory set). However, RT differences for the complex version of the task failed significance. Theoretical implications of the results for Henry’s (1960) memory drum theory of neuromotor reaction were discussed.     

Examining the Time Course of Attention During Golf Putts of Two Different Lengths in Experienced Golfers

A dual-task paradigm was used to investigate the time course of attention during putting relative to task difficulty (6 ft vs. 12 ft). Putting performance and reaction time (RT) were measured while 20 experienced golfers responded verbally to an auditory tone presented at 3 probe positions (PP) during the putt: backswing initiation (PP1), backswing peak (PP2), and before impact (PP3). There were 2 significant main effects for putting performance: task difficulty (better performance on the short putt) and probe position (worse performance at PP1 vs. PP3 and Catch Trials). During the short putt, there were no significant differences in RT as a function of PP, indicating that attentional demand remained constant throughout the stroke. RT of the long putt was significantly longer than the short putt, indicating that the long putt required greater attention. Skill level was examined as a potential moderating factor but did not significantly moderate results.     

Temporal preparation decreases perceptual latency: Evidence from a clock paradigm

A clock paradigm was employed to assess whether temporal preparation decreases the time to detect the onset of a stimulus—that is, perceptual latency. In four experiments participants watched a revolving clock hand while listening to soft or loud target tones under high or low temporal preparation. At the end of each trial, participants reported the clock hand position at the onset of the target tone. The deviation of the reported clock hand position from the actual position indexed perceptual latency. As expected, perceptual latency decreased with target tone intensity. Most importantly, however, greater temporal preparation decreased perceptual latency in all four experiments, especially for soft tones, which supports rather directly the idea that temporal preparation diminishes the duration of perceptual processing.     

Auditory and visual reaction time in adults during long performance

Better to understand the relation of auditory to visual reaction time (RT) tasks during a long period (320 min.) as well as the evolution of these performances along time, 24 subjects were tested. RT tasks were delivered at 10-min. intervals for 320 min. Correlations between auditory and visual RTs and cross-correlation functions were calculated. Our results confirmed their association, which was maintained throughout the experiment. There were no significant differences in the mean RT by sex or time of day; however, differences were found for the trend slope between type of stimulus and sex.