Influences of multiple spatial stimulus and response codes on orthogonal stimulus—response compatibility

When up-down stimuli are mapped to left-right responses, an up-right/down-left mapping advantage is found that is modified by response eccentricity and hand posture. These effects can be attributed to correspondence of asymmetric stimulus and response codes formed relative to multiple reference frames. We examined the influence of stimulus-set location on these orthogonal stimulus-response compatibility (SRC) effects. In Experiment 1, the stimulus set appeared in the upper or lower display positions. A spatial code for stimulus-set location was formed, producing Simon-type response eccentricity and hand posture effects, but this code had no influence on the coding of the relevant stimuli. In Experiment 2, the stimulus set appeared in the left, center, or right positions relative to the response location, which also varied, to dissociate the effects of response location, relative to the stimulus display and body midline. The former factor influenced the orthogonal SRC effect for both unimanual switch movements and bimanual keypresses, and the latter factor influenced the effect for only unimanual switch movements. Stimulus-set location causes orthogonal Simon-type effects when varied along the stimulus dimension and provides a referent for response coding when varied along the response dimension.     

No overall right-left prevalence for horizontal and vertical Simon effects

The present study confirmed that there is no overall right-left prevalence effect for Simon tasks, in which stimulus location is irrelevant, when (1) the stimulus and response sets vary along both horizontal and vertical dimensions simultaneously, (2) the stimulus set varies along both dimensions, but the response set varies along only one dimension, and (3) the stimuli and responses vary in one of four possible locations and responses are made by a unimanual joystick movement. In all experiments, Simon effects of similar magnitude were evident for both the horizontal and the vertical dimensions. The findings suggest that the right-left prevalence effect observed with two-dimensional location-relevant tasks is not due to stronger overall automatic activation of horizontal codes but to different translation efficiencies in intentional response selection processes.     

A Simon effect in pigeons

Pigeons pecked left versus right keys contingent upon the color presented at 1 of those locations. Spatial-response latencies were shorter when the color appeared at the same location as the required response than at the opposite location. This Simon effect occurred when the stimulus on the alternative key was constant, varied from trial to trial, or changed when the color cue appeared and when the reinforcement probability for correct responses was the same on corresponding as on noncorresponding trials. Humans performing the same task by touching the keys also showed the Simon effect. These findings demonstrate that for pigeons, too, a relevant symbolic cue activates a spatial code that produces faster responses at the location corresponding with the activated code.     

Dual-task performance with ideomotor-compatible tasks: is the central processing bottleneck intact, bypassed, or shifted in locus?

The present study examined whether the central bottleneck, assumed to be primarily responsible for the psychological refractory period (PRP) effect, is intact, bypassed, or shifted in locus with ideomotor (IM)-compatible tasks. In 4 experiments, factorial combinations of IM- and non-IM-compatible tasks were used for Task 1 and Task 2. All experiments showed substantial PRP effects, with a strong dependency between Task 1 and Task 2 response times. These findings, along with model-based simulations, indicate that the processing bottleneck was not bypassed, even with two IM-compatible tasks. Nevertheless, systematic changes in the PRP and correspondence effects across experiments suggest that IM compatibility shifted the locus of the bottleneck. The findings favor an engage-bottleneck-later hypothesis, whereby parallelism between tasks occurs deeper into the processing stream for IM- than for non-IM-compatible tasks, without the bottleneck being actually eliminated.     

A feature-integration account of sequential effects in the Simon task

Recent studies have shown that the effects of irrelevant spatial stimulus-response (S-R) correspondence (i.e., the Simon effect) occur only after trials in which the stimulus and response locations corresponded. This has been attributed to the gating of irrelevant information or the suppression of an automatic S-R route after experiencing a noncorresponding trial—a challenge to the widespread assumption of direct, intentionally unmediated links between spatial stimulus and response codes. However, trial sequences in a Simon task are likely to produce effects of stimulus- and response-feature integration that may mimic the sequential dependencies of Simon effects. Four experiments confirmed that Simon effects are eliminated if the preceding trial involved a noncorresponding S-R pair. However, this was true even when the preceding response did not depend on the preceding stimulus or if the preceding trial required no response at all. These findings rule out gating/suppression accounts that attribute sequential dependencies to response selection difficulties. Moreover, they are consistent with a feature-integration approach and demonstrate that accounting for the sequential dependencies of Simon effects does not require the assumption of information gating or response suppression.     

The role of joint attention in the development of infants' play with objects

Year-old infants' play was scored within and outside joint attention with mother and when alone for four levels of maturity: stereotypical, inappropriate relational, appropriate relational, functional. Maternal sensitivity within joint attention was rated on two measures: following infants' interests and scaffolding infants' activities. Infants' play was more advanced with mother than when alone. With mother, infants had more functional and appropriate relational play within joint attention and more stereotypical play outside joint attention, indicating more advanced play within joint attention and more immature play outside joint attention. Functional play within joint attention, but not outside joint attention, correlated with functional play when alone. Mothers' ability to scaffold infants' activities within joint attention may be particularly facilitative to infants' advanced play.     

Stimulus-response compatibility with pure and mixed mappings in a flight task environment

The present study examined the stimulus-response compatibility (SRC) effect in a simulated flight environment. Experiments 1 and 2 tested the effect with pure and mixed mappings in flight tasks by using attitude displays with inside-out and outside-in formats, whereas Experiments 3 and 4 used a simplified display and tasks. The SRC effect was obtained with mixed mappings when responses were turns of a flight yoke (Experiments 1-3). In contrast, the SRC effect was absent with mixed mappings when they were buttonpresses (Experiment 4). Analyses of sequential effects suggest that the reduction in Experiments 1-3 can be attributed to reduction in the frequency of trials for which the congruent mapping repeats, but the elimination in Experiment 4 cannot be. Implications of the findings are discussed in the context of aviation cockpit design.     

The acquisition of task-specific productions and modifications of declarative representations in spatial-precuing tasks

The stimulus-response translation stage of human information processing plays a mediating role of relating stimuli to assigned responses. The translation stage has been implicated as the locus of a pattern of differential precuing benefits obtained in spatial-choice tasks (Proctor & Reeve, 1986; Reeve & Proctor, 1985): When pairs of finger responses from the middle and index fingers of each hand are precued, the two leftmost and two rightmost responses show the greatest benefit. This pattern of differential benefits, which occurs regardless of whether the hand placement is adjacent or overlapped, has been attributed to spatially coded representations of the stimulus and response sets in the translation stage. Experiment 1 evaluated whether the mediating role of the translation stage changes with practice. All precued pairs of responses showed equivalent benefits in the last of three sessions. This result indicates that the spatial representations used initially to translate between stimuli and responses have been altered to be more efficient or have been replaced by productions that directly specify fingers. Experiment 2 used a fourth session in which subjects were transferred from the overlapped hand placement to the adjacent placement, or vice versa. For subjects in the former condition, the pattern of differential precuing benefits reappeared in the transfer session. This lack of transfer is consistent with the hypothesis that task-specific productions develop with practice that directly relate stimuli to fingers. For subjects who practiced with the adjacent placement and switched to the overlapped placement, only a nonsignificant tendency existed for the pattern of differential precuing benefits to reappear. This failure of the pattern to reappear could indicate that spatial representations continue to be used to translate between stimuli and responses. Alternatively, as occurs with the overlapped placement, task-specific productions could be acquired that relate stimuli to fingers. If so, the failure of the pattern of differential precuing benefits to reappear would reflect a modification in the representations that are used for translation in the transfer session. Specifically, if subjects were coding the stimulus and response sets on the basis of the distinction between the two hands, as well as the spatial distinction, the differential benefits would be minimized because hand coding should benefit different responses from those benefitted by spatial coding. These alternative explanations were evaluated in Experiment 3 by having subjects who practiced with the adjacent placement switch to a placement in which the hands were crossed completely.(ABSTRACT TRUNCATED AT 400 WORDS)     

The virtues of scientific psychology: A reply to Harzem

Harzem recently expressed the opinions that, beginning in the 1960s, the progress of scientific psychology has been deferred and that psychological research has failed to address important social issues. He proposed that progress be resumed by taking up, anew, the experimental analysis of behavior. The present reply provides evidence inconsistent with Harzem's assertions regarding the state of contemporary, scientific psychology and questions the wisdom of disregarding the significant body of data and theory that currently are available to pursue the, as yet, unfulfilled promises of the experimental analysis of human behavior.