Sequential effects in an eight choice serial reaction time task

Data from an eight choice serial reaction time experiment using two different response-stimulus intervals were examined for sequential effects by separating out the mean reaction times for each stimulus following every other stimulus. This analysis revealed differences in performance under the two response-stimulus interval conditions not shown by the conventional partitioning of the reaction times into those for repetitions and for non-repetitions.     

Sequential effects in a two-choice serial reaction task

Twenty-four subjects performed a symbolic two-choice serial reaction task under four conditions. These were with a delay from previous response to onset of next stimulus of 100 millisec, 600 millisec., 2 sec., and a fourth condition of 2 sec. delay with verbal prediction of the next stimulus. A positive recency or repetition effect occurred at 100 millisec. delay where RTs to repeated stimuli were faster than RTs to alternate stimuli. At 600 millisec. this effect was still present, though much reduced. The 2 sec. delay gave a negative recency effect where RTs were slower to repeated than to alternate stimuli. This effect increased significantly with simultaneous prediction of the next stimulus. The verbal predictions themselves displayed negative recency. Run analysis of the four conditions revealed strking differences. These results emphasize the need for analysing the microstructure of choice RT situations and reveal deficiencies in present models.     

Sequential effects in auditory choice reaction time tasks

This paper concerns sequential effects in choice reaction time tasks. Performance in two interleaved auditory tasks was examined, and two general types of sequential effects were revealed. First, a response repetition effect occurred: Subjects were facilitated in responding when both the stimulus and the response were immediately repeated. Generally, it appeared that subjects were operating according to the bypass rule—that is, repeat the response if the stimulus or some aspect thereof is repeated from the preceding trial; otherwise, change the response. In addition, the experiment also revealed a second type of sequential effect, known as a task-switching effect. Subjects were overall slower to respond when the task changed between adjacent trials than when there was no task change. A final result was that subjects were markedly impaired when the stimulus changed but the same response had to be repeated. This finding has been reported elsewhere when purely visual tasks have been used. Hence, it seems that particular difficulties arise, in such sequential testing situations, when type-distinct stimuli are grouped into the same response categories.     

Specific sequence effects in the serial reaction time task

The Serial Reaction Time (SRT) task was used in 2 experiments to determine if the specific sequence used by the task influences implicit learning. In Experiment 1, participants performed the SRT task with the locations of the stimuli determined by a commonly used fixed sequence (taken from P. J. Reber & L. R. Squire, 1998), by a fixed sequence that was uniquely generated for each participant, or at random. Experiment 2 used the same basic design, but the random condition was changed so that each possible transition between responses was seen the same number of times, making it more comparable to the fixed-sequence conditions. Results from both experiments indicate that the specific sequence used in the SRT task influences the strength of implicit learning effects. Follow-up analyses show that the strength of implicit learning can be linked to the presence of particular types of triads within the sequence. The authors suggest that future researchers should not use on a single fixed sequence across all participants when using the SRT task but should instead generate different fixed sequences for each participant to enhance the generalizability of their results.     

Sequence learning at optimal stimulus-response mapping: evidence from a serial reaction time task

We propose a new version of the serial reaction time (SRT) task in which participants merely looked at the target instead of responding manually. As response locations were identical to target locations, stimulus-response compatibility was maximal in this task. We demonstrated that saccadic response times decreased during training and increased again when a new sequence was presented. It is unlikely that this effect was caused by stimulus-response (S-R) learning because bonds between (visual) stimuli and (oculomotor) responses were already well established before the experiment started. Thus, the finding shows that the building of S-R bonds is not essential for learning in the SRT task.     

Sequential effects of catch-trials on choice reaction time

The aim of the study was to examine whether or not choice reaction time (RT) depends on catch-trial frequency. The results show a significant increase of mean RT as the catch-trial frequency increases from zero to 0.77. A similar effect has been shown previously in simple RT experiments. The interpretation of these effects on simple RT supposes the existence of an inverse relationship between catch-trial frequency and anticipated response frequency. This cannot be extended to a choice RT task since the subject must wait for the stimulus to arrive before deciding which is the appropriate response. The interpretation of the present results proposes preparatory adjustments prior to the arrival of the stimulus. Sequential effects found suggest that (1) the tendency to prepare for a stimulus at a trial was stronger when a stimulus was presented at the preceding trial than after a catch-trial, and (2) the frequency effects of catch-trials can be explained completely in terms of sequential effects.     

Sequential effects of foreperiod duration and conditional probability of the signal in a choice reaction time task

The aim of the present study was to determine whether the negative relationship usually found between reaction time and foreperiod duration in the variable foreperiod paradigm is entirely due to sequential foreperiod effects. It has been shown that when a particular foreperiod has been preceded by a longer one on the previous trial, reaction time is longer than when the preceding foreperiod was equal or shorter. This may be sufficient to explain the increase in reaction time observed for short foreperiods in variable foreperiod conditions.The present results show that, when sequential effects were controlled by the elimination of all trials where the foreperiod was shorter than the preceding one, the negative slope of the reaction time-foreperiod function diminished but did not disappear. The results suggest an interpretation of the role of conditional probability of stimulus arrival in terms of variation in the tendency to reprepare when the moment initially chosen for preparation appears to fall short of the moment at which the stimulus is actually presented.     

The additivity of stimulus-response compatibility with perceptual and motor factors in a visual choice reaction time task

One hundred and four participants performed a two-choice reaction time task requiring button-press responses to visual stimuli. Two levels of stimulus-response compatibility were factorially combined with two levels of stimulus discriminability and two levels of response repertoire. Results showed that the effects of these three variables were additive both in terms of mean reaction time as in terms of reaction time variances. The implication of this outcome is discussed in terms of the underlying information processing stage structure.     

Stimulus congruence and stimulus-response compatibility: Two variables disentangled in an auditory reaction time task

Abstract

Stimulus—response (S-R) compatibility was a tem fmt used by Wtts and Seeger (1953) to describe effcts observed on reaction time (RT) when the stimulus—response relationship was varied, as in the following instructions: “move to tbe right when the stimulus appears on the right” (compatible) or “move to the left when the stimulus appears on the right” (incompatible). This term was later employed in a broader sense (Simon & Rudell, 1967) with paradigms involving elaborate stimuli, such as the verbal command ‘RIGHT’ delivered to the right tar (compatible) or to the left ear (incompatible). In such paradigms. subjects respond faster when the response is delivered on the same side as the stimulus (the so-called “Simon effect”). It has been shown, however, that this effect could be reversed under some circumstanas in the visual domain. In this paper, we report data showing that it can also be reversed in the auditory domain when using the above-mentioned verbal commands. This brings further evidence that stimulus-response compatibility and the Simon effect difier in essence, with the latter effect reflecting the influence of stimulus congruence, the correspondence relationship borne by the two simultaneous characteristics of the stimulus. Stimulus congruence and stimulus-response compatibility had indeed independent influences on RT, which in a serially connected information-processing modcl would imply that they act upon independent stages.     

Assessment of sexual preference using a choice reaction time task

The purpose of this study was to investigate the use of a choice reaction time task, during which slides of sexually explicit and neutral stimuli were used as an interference task, to differentiate between groups of individuals on the basis of their sexual preference. Twenty subjects, in each of the four groups (heterosexual males, heterosexual females, homosexual males, and homosexual females), participated in this study. Sexual orientation was determined by self-report. Subjects were given a choice reaction time with interference task, followed by a recall incidental learning task. A significant higher-order interaction was found among gender, orientation, and stimulus type for all four groups. This interaction indicated a longer reaction time to slides depicting preferred sexual partners than to nonpreferred sexual partners or neutral scenes. These results indicate that sexual arousal does interfere with cognitive processing. A main effect for gender was found for the incidental learning task, with males having the fewest errors.     

Effects of stimulus-response correspondence and verbal expectancy on choice reaction time.

The effects of S-R correspondence, verbal prediction, and stimulus discriminability were examined in a discrete, two-choice reaction-time task. Correctness of prediction and S-R correspondence were significant main effects. In addition, responses were significantly faster for correct predictions on noncorresponding trials than for incorrect predictions on corresponding trials. This latter finding indicates that an expectancy mechanism can partially offset the negative effect of spatial S-R noncorrespondence on absolute magnitude of choice reaction time.     

The effects of force and direction uncertainty of choice reaction time in an isometric force production task.

The two experiments reported examined the temporal organization of force and direction motor-programming processes in a step-input tracking type task. Both experiments observed a reduction in reaction time in the direction-uncertain conditions compared to the direction-certain ones. Thus it seems as though the direction decision does not have to precede the selection of the proper amount of forces. Experiment 2 observed an under-additive interaction between levels of direction uncertainty (certain or uncertain) and levels of force uncertainty (certain or uncertain). This interaction was interpreted as support for the programming of force and direction and thus, strongly supports the parallel model of programming recently proposed by Klapp (1977a,b).     

Stimulus-response compatibility and sequential learning in the serial reaction time task

The serial reaction time (SRT) task is a commonly used paradigm to investigate implicit learning. In most studies the settings originally introduced by Nissen and Bullemer are replicated, i.e., subjects respond to a visuo-spatial sequence of stimulus locations by pressing spatially compatible arranged keys. The present experiment was designed to explore to what degree the sequential learning observed under these conditions depends on the use of locational sequences. Under otherwise identical conditions, first the S-R compatibility was reduced by using symbols instead of locations as stimuli, and second, the connectibility, i.e, the ease of connecting successive stimuli into coherent pattern, was varied. Effects on reaction times (RT) in the SRT task and on explicit memory in a generation task were evaluated. The results indicate that the connectibility of the stimuli has no effect at all and that S-R compatibility influences only the general RT level but does not seem to modify the learning process itself. Thus, the data are more consistent with the notion that learning is based primarily on the sequence of responses rather than on the sequence of stimuli. Moreover, a post hoc classification of subjects with regard to the amount of explicit sequence knowledge they have acquired reveals a striking modification of the general result: The RT difference between responses to locations and symbols vanishes in the course of learning for the complete explicit knowledge group. In order to account for this effect, we presume that the response control of these subjects shifts from stimuli to motor programs, so that RTs become increasingly independent of the stimuli used.     

Effector-related sequence learning in a bimanual-bisequential serial reaction time task

In a bimanual-bisequential version of the serial reaction time (SRT) task participants performed two uncorrelated key-press sequences simultaneously, one with fingers of the left hand and the other with fingers of the right hand. Participants responded to location-based imperative stimuli. When two such stimuli appeared in each trial, the results suggest independent learning of the two sequences and the occurrence of intermanual transfer. Following extended practice in Experiment 2, transfer of acquired sequence knowledge was not complete. Also in Experiment 2, when only one stimulus appeared in each trial specifying the responses for both hands so that there was no basis for separate stimulus-stimulus or separate response-effect learning, independent sequence learning was again evident, but there was no intermanual transfer at all. These findings suggest the existence of two mechanisms of sequence learning, one hand-related stimulus-based and the other motor-based, with only the former allowing for intermanual transfer.     

The influence of response-effect compatibility in a serial reaction time task

Participants performed a serial reaction time task, responding to either asterisks presented at varying screen locations or centrally presented letters. Stimulus presentation followed a fixed second-order conditional sequence. Each keypress in the experimental groups produced a contingent, key-specific tone effect. The critical variation concerned the mapping of tones to keys. In Experiment 1, keypresses in one control condition produced noncontingent tone effects, while in another control condition there were no tone effects. In Experiment 2, three different key-tone mappings were compared to a control condition without tone effects. The results show that tone effects improve serial learning when they are mapped to the response keys contingently and in a highly compatible manner. The results are discussed with reference to an ideomotor mechanism of motor sequence acquisition.     

Probability effects in choice reaction time tasks

This paper contains a short review of the main results that were obtained by the author in a series of experiments that constituted a study of the effects of signal probability on choice reaction time. The effects of stimulus probability are shown to be influenced by the following variables: (1) differences in the method of varying stimulus probability, (2) differences in task complexity, (3) differences in S-R code, and (4) differences in Ss’ motivation. The data that are considered here are the overall mean RT for particular signals and the mean RT for sequential repetitions. Two questions, related to the psychological “nature” of the probability effects in choice RT are discussed: (1) The question of the relationship between the relative frequency and the number of alternatives as two different ways of determining the probability effect in choice RT; and (2) the question of identifying the main determinants of the trial-to-trial variability of RT in such experiments.

     

The effects of spatial stimulus-response compatibility on choice time production accuracy and variability

Five experiments examined the relations between timing and attention using a choice time production task in which the latency of a spatial choice response is matched to a target interval (3 or 5 s). Experiments 1 and 2 indicated that spatial stimulus-response incompatibility increased nonscalar timing variability without affecting timing accuracy and that choice reaction time practice reduced choice time production variability. These data support a "temporal discounting" model in which response choice and timing occur in series, but the interval timed is shortened to account for nontemporal processing. In Experiment 3, feedback and anticipation task demands improved choice time production accuracy. In Experiments 4 and 5, the delay between the start-timing and choice-decision signals interacted with choice difficulty to affect choice time production accuracy and variability when timing a 3- but not a 5-s interval, suggesting that attention mediates timing before and after an interruption in timing.     

Irrelevant response effects improve serial learning in serial reaction time tasks

Tones were introduced into a serial reaction time (SRT) task to serve as redundant response effects. Experiment 1 showed that the tones improved serial learning with a 10-element stimulus sequence, but only if the tone effects were mapped onto the responses contingently. Experiment 2 demonstrated that switching to noncontingent response-effect mapping increased SRT only when participants had previously adapted to contingent response-effect mapping. In Experiment 3, the beneficial influence of contingent tone effects on serial learning occurred only when there was sufficient time between the response effects and the next imperative stimuli. The results are discussed in terms of the ideomotor principle. It is claimed that an internal representation of the to-be-produced tone effects develops and gains control over the execution of the response sequence.