Movement-based compatibility in simple response tasks

Previous studies reported that movement observation affected movement execution. Using one and the same set of responses (i.e., lifting or tapping the finger), correspondence effects were observed for simple responses when the go-signals were similar to the responses (i.e., movies of finger movements) but not when they were dissimilar (i.e., moving squares). The difference was attributed to a higher degree of ideomotor compatibility with visible limb movements. We tried to provide further evidence for ideomotor theory by manipulating the degree to which different responses matched one and the same set of stimuli (drifting sine-wave gratings). To this end, we measured simple reaction time of dynamic (hand movements) or static (key presses) movements in response to the onset of object motion. Object motion and dynamic responses showed ideomotor compatibility without looking alike; however, both stimulus and response involved continuous displacements. Correspondence effects were observed for dynamic responses, but not for static responses.     

Locus of semantic interference in picture-word interference tasks

Picture#x2014;word interference studies typically show that semantically related distractor words embedded within a picture slow picture-naming responses, relative to unrelated ones. This semantic interference effect is commonly interpreted as arising from the competition of lexical#x2014;semantic (e.g., Schriefers, Meyer, & Levelt, 1990) or lexical#x2014;phonological (e.g., Starreveld & La Heij, 1996) codes. The experiment reported here tests a crucial assumption shared by these accounts#x2014;namely, that the effect reflects a lexical, rather than a nonverbal, conceptual conflict. Pictures were named while participants attempted to ignore embedded distractors that were in either verbal or pictorial format. The presence of both words and pictures substantially interfered with naming responses, but only words, not pictures, were found to induce semantic interference. These findings support the claim that for semantic interference to arise, both target picture and distractor have to be lexicalized. Consequently, a general conceptual locus of the effect can be excluded, and the claim that semantic interference is based on a lexical conflict is confirmed.     

Response-effect compatibility in manual choice reaction tasks

This study investigated whether compatibility between responses and their consistent sensorial effects influences performance in manual choice reaction tasks. In Experiment 1 responses to the nonspatial stimulus attribute of color were affected by the correspondence between the location of responses and the location of their visual effects. In Experiment 2, a comparable influence was found with nonspatial responses of varying force and nonspatial response effects of varying auditory intensity. Experiment 3 ruled out the hypothesis that acquired stimulus-effect associations may account for this influence of response-effect compatibility. In sum, the results show that forthcoming response effects influence response selection as if these effects were already sensorially present, suggesting that in line with the classical ideomotor theory, anticipated response effects play a substantial role in response selection.     

Stimulus-response compatibility affects auditory Stroop interference

The contribution of stimulus-response compatibility to Stroop interference was tested in an auditory version of the Stroop test. The words “high” and “low” were presented in high and low pitches with either the pitch or the word designated as the relevant dimension. College students categorized the relevant stimulus dimension with a verbal response, a buttonpress, or a pitched hum. Significant interference occurred in the incompatible conditions (pitch-verbal, word-hum, pitch-button), but not in the compatible conditions (pitch-hum, word-verbal, word-button). The results indicated that stimulus-response compatibility was an important determinant of observed interference. It was suggested that stimulus-response incompatibility contributed to the response competition that presumably occurs in Stroop tasks.     

Contextual interference effects with two tasks

The present study was intended to test whether the standard contextual interference effect would be observed when only two patterns were practiced in blocked or random schedules of multisegment movement tasks rather than three patterns which is the norm. In line with the basic effect, Blocked learners' performance was closer to ideal during acquisition, but Random learners had smaller errors at 24-hr. retention. In addition, random learners had better recall of the details of the patterns they had practiced. Learners' predictions of retention performance did not match the group differences actually observed.     

Selecting mapping rules and responses in mixed compatibility four-choice tasks

Four-choice reaction tasks with a mixture of compatible and incompatible mappings were used to examine implications of the views that response selection occurs (a) in two stages (selection of the appropriate mapping rule, followed by application of the rule) and (b) by means of a second, direct route when the mappings for all possible stimuli are known to be compatible. All experiments showed, consistent with the two-stage view, that responses were faster and compatibility effects smaller when the mapping distinction corresponded to the left-right or inner-outer locations for the stimulus-response ensemble than when it did not. Moreover, precuing benefits tended to be larger when the cued responses had the same mapping than when they did not. There was an added benefit when both precued responses were compatible, rather than incompatible, consistent with the view that selection between compatible responses can proceed along a direct route. Received: 9 July 1997 / Accepted: 5 February 1998     

Orthogonal cross-task compatibility: Abstract spatial coding in dual tasks

Spatially orthogonal stimulus and response sets can produce compatibility effects. To explore whether such effects cross the border of logically independent tasks, we combined a nonspeeded visual task requiring verbal report of a stimulus movement (up vs. down) with an auditory reaction time task that required a unimanual movement to the left or right. Two experiments demonstrated that up stimuli facilitate rightward responses and down stimuli facilitate leftward responses, relative to the opposite combinations, thus producing an orthogonal cross-task compatibility effect. This effect presumably arises from abstract coding with respect to the salient referents of a spatial dimension (i.e., up and right), so that coactivation of structurally similar codes leads to mutual priming even when the codes refer to different tasks. The present evidence for abstract spatial coding extends previously proposed coding principles from single-task settings to dual-task settings.     

Stimulus-response compatibility effects in go-no-go tasks: a dimensional overlap account

According to the automatic response activation hypothesis of the dimensional overlap (DO) model (Kornblum, Stevens, Whipple, & Requin, 1999), stimulus-response compatibility effects are expected to occur in go-no-go tasks. This prediction is confirmed in two experiments in which subjects moved a hand to one side of the field on presentation of a go stimulus. Although the direction of movement was known in advance and the spatial attribute of the go stimuli was irrelevant to the go-no-go decision, the subjects' response time was shorter when the spatial attribute to the go stimulus corresponded to that of the response than when it did not. These effects are shown to depend on the similarity of the go and the no-go stimuli, as well as on whether the spatial attribute of the go stimuli was its actual location or its meaning. We discuss these results in terms of the temporal dynamics of automatic and controlled response processes, as hypothesized in the DO model.     

Imagery,rehearsal, and the compatibility of input-output tasks

Two experiments tested the proposition that recall in an imagery task would be facilitated when the processes instigated during original input and during a rehearsal interval were similar to (compatible with) processes assumed to be initiated by two retrieval formats. In both experiments the subjects listened to tape-recorded messages which described the placements of numbers in an imaginary mental matrix. Experiment 1 used four modes of presenting the original information about the placement of the numbers. Two of the input modes were expected to foster the use of imagery: listening to the tape-recorded messages (L), and listening while shadowing (vocalizing) the messages (LV). The other modes of presentation were expected to encourage verbalized rather than imaginal encoding: listening plus silent reading (LR), and listening plus reading aloud (LRV). Two types of recall tasks were used, one which emphasized imaginal coding (matrix recall) and one which emphasized verbal coding (direction recall). Recall was highest when the input and output tasks were assumed to involve similar types of processing. Thus, Groups L and LV showed higher recall than Groups LR and LRV on the matrix task, but the converse was true for the direction task. In addition, rotation of the information yielded different characteristics for the input-output conditions. Experiment 2 introduced rehearsal instructions. Visualizing rehearsal was more beneficial to matrix recall than verbalizing rehearsal or no explicit rehearsal instructions, and verbalizing rehearsal aided direction recall more than visualizing rehearsal. Various models were discussed.     

Color-word interference in relation to comparative compatibility: evidence for two sources of interference]

In previous studies on colour-word interference ('Stroop-phenomenon') stimulus-response-compatibility (word-speech, colour-speech) and task mode (word reading, colour determining) have usually been confounded or not been crossed completely. An experiment is reported where these two factors were varied orthogonally (besides type of stimulus: incongruent, congruent and control). Compatibility was varied by using response keys with varying labelling of the keys (colours or words). The results show--contrary to traditional expectations--the usual pattern of interference in spite of the response key conditions. The existence of response delays of different magnitude indicates separate sources of interference. Encoding interference is found under conditions of high-compatible colour determining by coloured response keys (colour-colour key), recoding interference under conditions of low-compatible reading (word-colour key), both presented here in an isolated form. Both modes of interference should therefore contribute to the interference under conditions of low-compatible colour determining which is the traditional Stroop condition. In an attempt to predict this complete interference encoding interference was shown to be the more stable predictor. The same was true of interference as measured here in a list version.     

The locus of interference in the Stroop and related tasks

Perceptual conflict and response competition interpretations of studies of color-word interference are briefly considered, and a study of the effect of semantic factors on color-word interference in a color comparison task is reported. It is concluded that the locus or interference is after, and not during, the processing of the word component of color-word stimuli.     

Dynamics of facilitation and interference in cue-priming and Simon tasks

In examining the selective suppression of responses activated by task-irrelevant stimulus attributes, such as in spatial conflict tasks, two different approaches have pointed to similar conclusions. In one approach (involving cue-priming procedures), variations of the stimulus-onset asynchrony (SOA) between task-irrelevant cues and subsequent target stimuli disclosed that the cues elicit activation of the congruent response, but this activation is subsequently suppressed. In another approach, a series of studies with the Simon task led to the formulation of the activation-suppression hypothesis. Analysis of RT distributions (in particular delta plots) disclosed that the task-irrelevant stimulus location elicits activation of the spatially corresponding response, but this activation is subsequently suppressed. The strength or efficiency of selective response suppression is expressed in the slope of the delta plot. In the present study, we combined these two approaches and found that the effects of SOA manipulation and the results of the distributional analysis converged and were positively correlated, suggesting that they involve a common mechanism of response activation followed by the selective suppression of that activation.     

Two distinct patterns of interference in between-attribute Stroop matching tasks

In between-attribute Stroop matching tasks, participants compare the meaning (or the color) of a Stroop stimulus with a probe color (or meaning) while attempting to ignore the Stroop stimulus’s task-irrelevant attribute. Interference in this task has been explained by two competing theories: A semantic competition account and a response competition account. Recent results favor the response competition account, which assumes that interference is caused by a task-irrelevant comparison. However, the comparison of studies is complicated by the lack of a consensus on how trial types should be classified and analyzed. In this work, we review existing findings and theories and provide a new classification of trial types. We report two experiments that demonstrate the superiority of the response competition account in explaining the basic pattern of performance while also revealing its limitations. Two qualitatively distinct interference patterns are identified, resulting from different types of task-irrelevant comparisons. By finding the same interference pattern across task versions, we were additionally able to demonstrate the comparability of processes across two task versions frequently used in neurophysiological and cognitive studies. An integrated account of both types of interference is presented and discussed.     

On the generality of logical recoding in spatial interference tasks

‘Simon’ and ‘recoding’ affects refer to interference by irrelevant spatial stimulus positions on the efficiency of responding to a stimulus. According to the Simon effect faster response times occur if the irrelevant stimulus position is compatible with the response position. Slower response times occur if stimulus and response positions are incompatible. The recoding effect is a reversed Simon effect, which occurs if the response assignment of the relevant stimuli is reversed, e.g., a red response button to a green stimulus and a green response button to a red stimulus. For this reversed response assignment response times are faster if stimulus and response positions are incompatible, and slower if stimulus and response positions are compatible. In this study the generality of the recoding effect in spatial interference tasks is investigated by using, first, spatial stimuli with directional attributes, second, verbal stimuli with a directional meaning, and, third, geometric figures without directional information. In all cases Simon effects as well as recoding effects were obtained. According to these results recoding does not presuppose a directional symbolic or verbal stimulus code, and the relation between the stimulus and the spatial response may be either direct, symbolic or arbitrary. Whether recoding or a Simon effect will occur depends on a late response decision stage in which the response code derived from the stimulus is either inverted (recoding effect) or not (Simon effect).     

Response selection errors in spatial choice reaction tasks

In a “Consistent” spatial choice reaction task, the same spatial relationship obtains between each stimulus and its appropriate response. In an “Inconsistent” task this is not so. The present experiment concerns errors in Inconsistent tasks. Duncan (in press) has suggested that, when two spatial S-R relationships are involved in a task, the dominant type of error is a response bearing to the stimulus the wrong one of the two relationships. Duncan's results, however, may be described by a different generalization. Rabbitt and Vyas (1973) have suggested that confusions occur between responses which, when made correctly, bear similar spatial relationships to their stimuli. In the present experiment, a new Inconsistent task is studied. The results support the account of Duncan (in press) but provide no support for that of Rabbitt and Vyas (1973). Partly on the basis of error results, Duncan (in press) proposed a model of response selection in the spatial choice reaction task. Unlike previous accounts, this model is not based on a set of individual “S--R” associations; operations generating sets of S--R pairs are involved.     

Response preparation and code overlap in dual tasks

In a dual-task paradigm, a visual-encoding task with a deferred verbal report of a moving target was combined with a speeded task, in which participants prepared a precued leftward or rightward key-press response that was withheld until an auditory go signal. We manipulated the interval between the response cue and the target for the visual-encoding task, the interval between this target and the go signal, and spatial cross-task compatibility between the direction of the target movement in the visual task and the speeded manual response. The results of two experiments suggest that visual encoding interferes with response preparation and with the initiation of the prepared manual response at a short target-go interval. Also, responses were faster in compatible than in incompatible trials, indicating a cross-task compatibility effect. Experiment 2 reversed this compatibility effect by instruction, suggesting that the compatibility effect is based on response-response overlap. In both experiments, response preparation impaired accuracy in the visual task. Taken together, these results suggest that response processes and visual encoding share common codes and processes.     

Temporal compatibility in dual motor tasks II: Simultaneous articulation and hand movements

Simultaneous articulation did not interfere with hand responses if the responses shared the same time period. Otherwise there was marked interference even after performance had stabilized with practice. These results generalized previous findings for simultaneous left-and right-hand responses (Klapp, 1979) to show that even highly distinctive responses can be generated in parallel only if they have compatible timing.     

Response monitoring and expectancy in random serial RT tasks

Two different sequential patterns have been reported in serial reaction-time (RT) tasks with random stimulus sequences, depending on the response-to-stimulus interval (RSI). When RSI is short a first-order repetition effect and a higher order benefit-only pattern are found, and when RSI is long a cost-benefit pattern is observed. In a series of three experiments, we found that the patterns are not unique for spatial dimensions, and that the benefit-only pattern does not appear for irrelevant stimulus features. The cost-benefit pattern, on the other hand, can shift to irrelevant locations, but not to irrelevant colour. Distributional analyses of the sequential effects demonstrate that the first-order repetition effect can be dissociated from the higher order effects. The results are interpreted as support for the role of response monitoring in the development of the benefit-only pattern at short RSI, while the first-order repetition effect is explained as repetition priming. With a long RSI, the cost-benefit pattern is confirmed as a low-level subjective expectancy process, which is primarily controlled by stimulus location. The data clearly strengthen the support for three different processes generating sequential effects in random serial RT tasks.     

Response time analysis in cognitive tasks with increasing difficulty

In the present study, speeded tasks with differing assumed difficulties of the trials are regarded as a special class of simple cognitive tasks. Exploratory latent growth modeling with data-driven shape of a growth curve and nonlinear structured latent curve modeling with predetermined monotonically increasing functions were used to analyze individual response-time change with an increase in task difficulty and to investigate latent response-time growth variables in relation to cognitive ability. A task that required participants to state the number of dots in a set was used as an example of a simple cognitive task with increasing difficulty; the response latencies obtained in this task and the magnitude of RT-IQ correlations changed depending on the complexity of the trial.Consistent with theoretical predictions, the individual speed of baseline performance was only weakly negatively correlated with each of the three measures of cognitive ability used in the study. The rate of change in response times with increasing task difficulty, estimated as a generalized growth parameter in the exploratory latent growth model, was significantly negatively related to cognitive ability. Response times of less intelligent individuals increased more rapidly in the task with increasing difficulty than the response times of highly intelligent individuals. Within the nonlinear structured latent curve modeling, the growth of response times with an increase in task difficulty was best described by a function that approached an oblique asymptote after an initial interval of convexity. A slope of this oblique asymptote was significantly negatively related to cognitive ability; for less intelligent individuals, the asymptote of response-time change was steeper than that for more intelligent individuals. In addition, a parameter that determined the shape of response-time growth trajectories on the interval of convexity was related to one of the three measures of cognitive ability.