Enhancement of the Simon effect by response precuing.

When stimuli are presented to the left or right of fixation, and stimulus location is irrelevant, responses are faster if the stimulus location coincides with the location of the assigned response. This phenomenon is called the Simon effect. The present study examined the influence on the Simon effect of attentional precues that signaled the likely stimulus location and intentional precues that signaled the likely response. Experiment 1 was a close procedural replication of an experiment by Verfaellie, Bowers, and Heilman (1988); consistent with their findings, the Simon effect was enhanced by the intentional precue and unaffected by the attentional precue. Experiments 2 and 3 demonstrated the importance of the intentional precue with simpler procedures that involved only intentional and attentional precues, respectively. Finally, the intentional precuing enhancement of the Simon effect was obtained when two stimuli were assigned to each response, regardless of whether the hands were uncrossed (experiment 4) or crossed (experiment 5). Overall, the results indicate that response precuing enhances the Simon effect and favor response-selection accounts over those that attribute the effect to stimulus identification.     

Parametric exploration of the Simon effect across visual space.

The Simon effect refers to the performance advantage for responding to the nonspatial identity of the target when the target's irrelevant location corresponds with the relative location of the response. The present study is a parametric examination of the magnitude of the Simon effect across visual space. Response keys were arranged along vertical, horizontal, and two diagonal axes, and stimuli were arranged in two concentric circles (near and far from fixation) along the same axes. The results show that the Simon effect is of similar magnitude regardless of stimulus-response axis. In contrast to findings from stimulus-response compatibility paradigms, there was no evidence in this study for the presence of an orthogonal compatibility effect or left-right prevalence effect, suggesting that these effects only arise when response location is relevant. The results demonstrate the robust generalizability of the Simon effect under different spatial conditions and thus broaden the relevance of the Simon effect to a variety of applications.     

Multidisciplinary creativity: the case of Herbert A. Simon

In the twentieth century, no person epitomized more dramatically the “Renaissance mind” than Herbert A. Simon (1916–2001). In aworking life spanning over 60 years, Simon made seminal contributions to administrative theory, axiomatic foundations of physics, economics, sociology, econometrics, cognitive psychology, logic of scientific discovery, and artificial intelligence. Simon's life of the mind, thus, affords nothing less than a “laboratory” in which to observe and examine at close quarters the phenomenon of multidisciplinary creativity. In this paper, we attempt to shed some light on the nature of Simon's creativity and the nature of his particular Renaissance mind. In particular, we have attempted here to articulate the cognitive style underlying Simon's multidisciplinary creativity.     

Playing the Simon game: Use of the Simon task for investigating human information processing

A little more than 40 years ago, J. R. Simon and colleagues introduced what is now called the Simon task, which yielded a correspondence effect known as the Simon effect. In this paper, I set Simon's contribution in the context of research on stimulus-response compatibility. The novel contribution of the Simon task is described, along with foundational findings using the task that Simon and colleagues reported. I acknowledge the significance of Simon's (1990) review chapter in generating my own interests in the Simon task and describe four selected lines of research from my lab that have been a result of those interests. The article concludes with a brief tribute to Simon and his contribution to experimental psychology.     

视觉运动Simon效应和认知Simon效应的影响因素及机制

Simon效应是指与反应要求无关的刺激位置和反应位置在同侧时, 个体反应更快更准确的现象。对于Simon效应的产生机制, 大多数研究者认为, 在不同实验情境中获得的Simon效应有共同的产生机制。但是, 越来越多的证据显示, 在刺激形式、排列方式、刺激—反应规则以及反应方式等因素的影响下, 存在两种不同性质的Simon效应, 即视觉运动Simon效应和认知Simon效应。视觉运动Simon效应源于刺激位置自动激活其同侧反应所产生的影响, 认知Simon效应源于转译生成的编码间的相互干扰, 两者分别与背侧通路和腹侧通路的加工有关。     

Stimulus congruence and the Simon effect

Summary A standard experimental procedure was implemented with novel response requirements to assess the hypothesis that the Simon effect is attributable not to the irrelevant stimulus-response relationship, but to the congruence between stimulus attributes. The stimulus ensemble consisted of the words LEFT and RIGHT, one of which was presented on each trial to the left or right of a central fixation point. The distinctive feature of the task is that subjects were asked to respond, by laterally placed keys, whether or not the stimulus word was in accord (i. e., congruent) with its location on the display. Asking subjects to judge stimulus congruence directly enables the effect of congruence to be assessed, as well as independent estimates of the two irrelevant S-R relationships that apply in the task — that is, between the response location and (1) the stimulus location (the Simon effect) and (2) the stimulus word (the reverse Simon effect). Marked effects were obtained in all three cases. Stimulus congruence remains in contention as a factor in the explanation of the Simon effect, but the strong effects of irrelevant S-R factors suggest that a more comprehensive account of the Simon effect is needed. An explanation in terms of stimulus salience, based on an interactive activational model, is briefly discussed.     

Attention precuing and Simon effects: A test of the attention-coding account of the Simon effect

Simon effects refer to the finding that choice-response latencies to a nonspatial aspect of a stimulus vary depending on the spatial correspondence between the stimulus position and the position of the correct response alternative. Recently, researchers have proposed an attention-coding account of Simon effects whereby the (irrelevant) stimulus spatial code involved in the generation of the effect is formed in the process of attentional orienting to the stimulus. This account predicts that if attentional orienting is unnecessary at stimulus onset, as when the stimulus appears at an attended location, Simon effects will not be observed. This prediction was tested by measurement of Simon effects in an attention-precuing task in which the stimulus was presented at attended and unattended locations. Significant Simon effects were observed independently of the focus of attention. This result was obtained over a large range of precue-target SOAs, and did not depend on whether central or peripheral precues were used to direct attention or on whether the relevant target dimension was color or form. Significant Simon effects were not observed when the precue-target SOA was 50 ms, irrespective of the other precue and task conditions. The data do not support the prediction of the attention-coding account and thus question the generality of the account in its current form. It is suggested that spatial and temporal uncertainties are important factors that influence the pattern of results, and that these factors must be incorporated into attention-coding models of the Simon effect.     

Inverting the Simon effect by intention

Summary The Simon effect indicates that choice reactions can be performed more quickly if the response corresponds spatially to the stimulus - even when stimulus location is irrelevant to the task. Two experiments tested an intentional approach to the Simon effect that assigns a critical role to the cognitively represented action goal (i. e., the intended action effect). It was assumed that the direction of the Simon effect depends on stimulus-goal correspondence, that is, that responses are faster with spatial correspondence of stimulus and intended action effect. Experiment 1 confirmed that the direction of the Simon effect was determined by spatial correspondence of stimulus and intended action effect, the latter having been manipulated by different instructions. Experiment 2 indicated that effects of correspondences unrelated to the action goal (i. e., stimulus to hand location or to anatomical mapping of the hand), contributed additively to the resulting Simon effect. It is discussed how current approaches to the Simon effect can be elaborated to account for these results.     

Cross-modal re-mapping influences the Simon effect

Tagliabue, Zorzi, Umiltà, and Bassignani (2000) showed that one's practicing of a spatially incompatible task influences performance in a Simon task even when the interval between the two tasks is as long as 1 week. In the present study, three experiments were conducted to investigate whether such an effect could be found in a cross-modal paradigm, whereby stimuli in the two tasks were presented in different modalities. Subjects performed either compatible or incompatible mappings in an acoustic spatial compatibility task and, after an interval of 5 min, 24 h, or 7 days, performed a visual Simon task. Results show that the spatially incompatible mapping task affected performance in the Simon task: The Simon effect was absent for all three intervals. This pattern is similar to the results of the Tagliabue et al. study, in which both tasks were performed in the same (visual) modality. Our findings disprove possible explanations based on episodic/contextual effects and support the hypothesis of a long-lasting spatial remapping that is not modality specific.     

Response strategies and the Simon effect

The study investigated whether the Simon effect, and its facilitation and interference components, shows up in reaction time (RT) or in movement time (MT), depending on the response strategy. Experiment 1 replicated a study by Hietanen and Rämä. Subjects had to press one of two lateralised keys in response to one of two stimuli. The stimuli were presented in the center (neutral condition) or to the left or right side (corresponding or non-corresponding conditions). To press the response key, a reaching movement was necessary, and both RT and MT were recorded. One group of subjects showed an RT facilitation effect and an MT interference effect. Another group of subjects showed both MT facilitation and MT interference effects. It was hypothesized that the two groups used different response strategies. In Exps. 2 and 3, the subjects were explicitly instructed to use the two strategies that were hypothesized for Exp. 1. The results showed that whether facilitation and interference manifest themselves in RT or MT depends on the response strategy adopted by the subjects.     

Response coding in the Simon task

Recent findings indicate that two distinct mechanisms can contribute to a Simon effect: a visuomotor information transmission on the one hand and a cognitive code interference on the other hand (see for e.g., Wiegand & Wascher, in Journal of Experimental Psychology: Human Perception and Performance 2005a). Furthermore, it was proposed that the occurrence of one or the other mechanism strongly depends on the way responses are coded. Visuomotor information transmission seems to depend on a correspondence between stimulus position and spatial anatomical status of the effector, whereas cognitive code interference is thought to be based on relative response location codes. To further test the spatial anatomic coding hypothesis, three experiments were conducted, in which the Simon effect with unimanual responses was investigated for horizontal (Experiment 1 and 2) and vertical (Experiment 3) stimulus-response (S-R) relations. Based on the finding of a decreasing effect function (indicating the presence of visuomotor information transmission) for horizontal and vertical S-R relations, it was concluded that visuomotor information transmission occurs whenever there is an overlap between the spatial stimulus feature and parameters of the motor representation of the response. Furthermore, the specific motor representation seems to be task dependent, that is, it entails those response parameters that clearly differentiate between the two response alternatives in a given task situation.     

Stimulus-response compatibility and the Simon effect: toward a conceptual clarification.

The current view that the Simon effect (Simon & Small, 1969) reflects stimulus-response compatibility (SRC) is questioned. Previous accounts of the Simon effect have overlooked stimulus congruity (SC), the correspondence relation borne by the two simultaneous aspects of the stimulus, a factor inevitably confounded in the Simon paradigm with irrelevant spatial S-R correspondence. The Hedge and Marsh (1975) reversal effect, replicated in Experiment 1, is reinterpreted as decisive evidence that the Simon effect is entirely accounted for by SC. Furthermore, in Experiment 2 irrelevant S-R correspondence was manipulated in the absence of any variation of SC, and the Simon effect vanished. It is concluded that the Simon effect, contrary to current opinion, represents a spatial variant of the Stroop effect and is irrelevant to the SRC issue. The view that mental operations proceed automatically at the stage of response determination loses one of its strongest empirical arguments.     

Simon says: Reliability and the role of working memory and attentional control in the Simon task

TheSimon effect refers to the observation that subjects identify targets (e.g., colors) faster when the irrelevant spatial location of the target corresponds to the location of the response key. Theoretical accounts of the Simon effect typically explain performance in terms of automatic and controlled processes. Furthermore, the relative contributions of automatic and controlled processes are held to change as a function of the proportion of compatible to incompatible trials (compatibility proportion). Data are presented demonstrating that the reliability of the Simon effect, indexed by correlating its magnitude within subjects across blocks of trials, varied substantially as a function of the compatibility proportion. When the compatibility proportion was high, so was reliability. When the compatibility proportion was low, reliability was low as well. The results are discussed in terms of the relative reliability of automatic and controlled processes and the role of working memory and attentional control in goal maintenance.     

Elimination of the enhanced Simon effect for older adults in a three-choice situation: Ageing and the Simon effect in a go/no-go Simon task

In a Simon task, participants show better performance when the irrelevant stimulus location corresponds with the response location than when it does not, and this effect is typically greater for older adults than for younger adults. To study the effect of cognitive ageing in the Simon task, we compared young and old adults using two versions of the Simon task: (a) a standard visual Simon task, for which participants respond with left and right key-presses to the red and green colours of stimuli presented in left and right locations; (b) a go/no-go version of the Simon task, which was basically the same, except that the shape of the stimulus in one third of the trials indicates that no response is to be made. In both tasks, both age groups showed the Simon effect. The magnitude of the effect for the standard Simon task was greater for the older adults than for the younger adults. Nevertheless, the two groups showed an equivalent Simon effect in the go/no-go version of the Simon task. Reaction time distribution analyses revealed basically similar functions for both age groups: a decreasing pattern of the Simon effect in the standard task and an increasing pattern of the effect in the go/no-go version of the task. The results suggest that older adults find it more difficult to suppress an automatic activation of the corresponding response, though this automatic activation was reduced in situations where the response was frequently inhibited.