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.     

Interactions between stimulus-stimulus congruence and stimulus-response compatibility

According to a central claim of Kornblum's dimensional-overlap model, response-related processes do not start before stimulus-related processes have been completed, which implies an additive relationship between effects of stimulus-stimulus congruence and stimulus-response compatibility. Three experiments were conducted to test this prediction. In Exp. 1, additive effects of color-word congruence (Stroop effect) and irrelevant spatial S-R compatibility (Simon effect) were in fact obtained. However, interactions between congruence and compatibility were observed in Exp. 2, where flanker-target congruence was varied, and in Exp. 3, where inter-level congruence of multi-level letters was manipulated. It is argued that these findings are inconsistent with the seriality assumption of the dimensional-overlap model, but that they support models claiming a temporal overlap of stimulus and response processing instead.     

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.     

Response programming and reaction time

A feature common in the literature is that, prior to responding, subjects have been able to preview the parameters of the movement they are required to make. This introduces the possibility of programming the movement before entering the reaction time period. It is argued that this has contributed to confusion in the literature, making it difficult to detect a consistent relationship between reaction time and motor task demands. Two experiments were conducted to clarify the position. Experiment I concealed the movement parameters prior to subjects responding ("no-preview" model), and this was contrasted with a study in the typical "preview" mode (Experiment II). It was concluded that the no-preview design is more appropriate to detecting changes in reaction time dependent on task parameters, and that the observed effects on reaction time reflect programming difficulty. A third experiment supported this conclusion     

Time but not force is transferred between ipsilateral upper and lower limbs

The authors compared the force and time endpoint accuracy of goal-directed ipsilateral upper and lower limb isometric contractions and determined the components of motor performance that can be transferred from 1 limb to the other after practice. Ten young adults (27.4 +/- 4.4 years) performed 100 trials that involved their matching peak force to a force-time target with ankle dorsiflexor and elbow flexor muscles. The peak force error and variability was greater for ankle dorsiflexor contractions than for elbow flexor contractions, whereas the timing error and variability did not significantly vary with limb. There was transfer of timing, but not force, of motor output between upper and lower limbs. The timing error of the elbow flexor contractions decreased by 23% when those contractions were preceded by ankle dorsiflexor contractions, and the timing error of the ankle dorsiflexors decreased by 24% when those contractions were preceded by elbow flexor contractions. These finding therefore suggest that timing of an aiming isometric contraction may be organized at a common part of the brain for the upper and lower limbs.     

Intentional and unintentional contributions to nonspecific preparation during reaction time foreperiods

The nonspecific preparation that follows a warning stimulus (WS) to speed responding to an impending imperative stimulus (IS) is generally viewed as a strategic, intentional process. An alternative view holds that WS acts as a conditioned stimulus that unintentionally elicits a tendency to respond at the moment of IS presentation as a result of a process of trace conditioning. These views were contrasted as explanatory frameworks for classical effects on reaction time of the duration and intertrial variability of the foreperiod, the interval between WS and IS. It is shown that the conditioning view accounts for the available data at least as well as the strategic view. In addition, the results of 3 experiments provide support for the conditioning view by showing that unintentional contributions to nonspecific preparation can be dissociated from intentional contributions.     

Application of the rubber hand illusion paradigm: comparison between upper and lower limbs

The “rubber hand illusion (RHI)” is a perceptual illusion, which allows the integration of artificial limbs into the body representation of a person by means of combined visual and tactile stimulation. The illusion has been frequently replicated but always concerning the upper limbs. The present study verified an analog illusion that can be called the “rubber foot illusion” (RFI). In a conjoint experiment using both a rubber hand and a rubber foot, brushstrokes were applied to the respective real and rubber limb placed alongside the real one. However, only the artificial limb’s handling was visible. The brushstrokes were given either synchronously, with a delay of ±0.5 s, or without tactile stimulation of the real limb. Questionnaire data and the proprioceptive drift towards the rubber limb (determined by calling on the subjects to show where they locate their unseen limb) defined the illusion strength. Results revealed that the illusion was induced in both limbs with comparable strength, but only in the synchronous condition.     

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 in an eight choice serial reaction time task using compatible and incompatible stimulus-response arrangements

Compatible and incompatible stimulus-response arrangements were compared using an eight choice reaction time task. With the compatible stimulus-response conditions, a stimulus was responded to quickly if it was:

1.

(1) adjacent to the ends or mid-line of the stimulus display,     

Response inhibition can affect reaction time to abrupt-onset visual displays

Reaction time (RT) to abrupt-onset stimuli has been widely used for more than a century to measure the duration of perceptuo-cognitive and motor processes [Donders, 1868/1969 Attention and Performance II (1969 Acta Psychologica 30 412-431)]. A complicating factor with the RT method is that of response withholding, or response inhibition (RI). The occurrence of RI (under this or other names) has been widely discussed in relation to studies of motor processes but has been largely ignored in relation to studies of perceptuo-cognitive processes. We demonstrate that RI can be a confounding factor when RT to abrupt-onset displays is used to study perceptual and cognitive processes. In experiment 1, new-object targets were more accurately detected than old-object targets in an unspeeded task, but were responded to more slowly in an RT task. Consistent with an interpretation in terms of RI, this pattern of results was dependent on the difficulty of target detection. The data of three further experiments also support predictions from the RI interpretation. It is suggested that RI may be an under-acknowledged factor in RT studies of perceptual and cognitive processes with abrupt-onset displays.     

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.     

Response programming,response production,and fractionated reaction time

Summary A feature common to many studies investigating the relationship between reaction time (RT) and motor task demands is that, prior to responding, subjects have been able to preview the parameters of the movement they are required to make. This introduces the possibility of preprogramming the movement before entering the RT period, thus making it more difficult to detect a consistent relationship between RT and motor task demands. A no-preview condition (movement parameters concealed prior to the subject responding) was used in the present study to avoid this confusion. Reaction time was fractionated using surface EMG recording, and premotor RT (central component) was found to vary with motor task demands in a fashion supporting a study by Sheridan (1981). Movement velocity was implicated as a factor influencing programming difficulty, with low velocity movements appearing to present the greatest problem. A strong negative correlation was observed between premotor RT and average movement velocity. A delay condition was incorporated into the present study to consider the retention in memory of the programmed information. Briefly, the pattern of results for the delay condition fell between the no-preview and preview conditions. The implications of these findings are discussed.     

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.     

Response selection in choice reaction time: Test of a buffer model

Two experiments were conducted to test a buffer model of response selection. Subjects reacted to the onset of one of six possible visual stimuli by pressing either a left- or a right-hand key. Two stimuli were assigned to one key Itwo-item set) and four stimuli were assigned to the other key flour-item set). An irrelevant monaural tone accompanied the visual stimulus in Experiment 1 but not in Experiment 2. Results of Experiment 1 showed that reactions were faster when the location of the tone corresponded with the response than when it did not, and the difference between these corresponding and noncorresponding conditions was greater for the two-item set than for the four-item set. Results supported the notion that the response selection process involved a serial self-terminating search of response buffers and that the tone determined the buffer searched first. In both experiments, reactions were faster to stimuli from the twoitem set than to stimuli from the four-item set     

Coordination of the upper and lower extremities

Simultaneous walking and hand clapping were utilized to examine the patterns of coordination between upper and lower limbs. Eighteen normal adult subjects were filmed at high speed under instructions to: (a) walk and clap at a self-determined “preferred” speed, (b) walk as fast as possible while clapping at the preferred speed, (c) walk at the preferred speed while clapping as fast as possible and (d) walk and clap as fast as possible. Temporal data and individual patterns of phase relations were analyzed. Results indicated a disruption of the preferred clap cycle when combine with fast walking. The degree of disruption was a function of the individual coordinative pattern at the preferred rate. It is concluded that: (a) the temporal patterning of the clap cycle can be dictated by the step cycle, (b) heel strike is the point about which the clap cycle is modulated, and (c) subjects can select from various modes of phase linkage.     

Stimulus-response compatibility and response preparation: effects on motor component of information processing for upper and lower limb responses

The effects of stimulus-response compatibility and response preparation on the motor component of the information processing system were investigated by analyzing the fractionated reaction time for the upper and lower limbs. The reaction time was divided into two periods with respect to the onset of electromyographic activity, premotor and motor times. The response preparation was manipulated by the probability that the locations of the precue and subsequent imperative stimulus corresponded. On a stimulus-response compatible task, subjects were required to release a key on the same side as an imperative stimulus, irrespective of the precued side. On an incompatible task, subjects were required to act in the reverse manner. The upper and lower limb responses were measured during both tasks. A repeated-measures design was used with 12 male university students. Analysis of the reaction and premotor times indicated that the stimulus-response compatibility effect became larger as response preparation decreased. The analysis of motor time yielded significant interactions between stimulus-response compatibility and limb and between response preparation and limb. These findings indicated that the motor component of information processing for the lower limb response is affected by both stimulus-response compatibility and response preparation.