The effects of stimulus–response mapping and irrelevant stimulus–response and stimulus–stimulus overlap in four-choice Stroop tasks with single-carrier stimuli.

The purpose of this study was to investigate whether and how stimulus–stimulus (SS) and stimulus–response (SR) consistency and SR congruence effects combine to produce the Stroop effect. Two experiments were conducted with 4-choice tasks in which SS and SR consistency and SR congruence effects were examined in isolation as well as in the Stroop task. The experiments were so designed as to remove the confound between SS and SR consistency that is ordinarily found in standard Stroop tasks and to pit SS consistency against the logical recoding hypothesis (A. Hedge & N. W. A. Marsh, 1975). The results indicate that SS and SR consistency both contribute to the Stroop effect and that they interact. This finding supports models such as the dimensional overlap model (e.g., S. Kornblum & J. W. Lee, 1995) that distinguish between SS and SR overlap. Simulation results from an interactive activation network, modeled after the dimensional overlap model, provide reasonable fits to the experimental data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-response compatibility and automatic response activation: evidence from psychophysiological studies

Effects of dimensional overlap between stimuli and responses on partial response activation were investigated within a priming paradigm with the help of event-related potentials. The likely position of a target stimulus (requiring a left or a right reaction) was indicated by an arrow precue. To test whether automatic response activation processes are triggered by the cue, the lateralized readiness potential was computed. It was found that responses congruent to the direction of the cue were activated about 200 ms after cue onset. This early process was unaffected by specific cue-response contingencies and was completely missing when a nonspatial (color) cue was used. A second response activation phase was observed, which was partially controlled by specific response instructions and subjective expectancies. It is concluded that when stimuli and responses overlap with respect to spatial attributes, automatic response activation process are triggered, which may later be replaced by the activation of an expected response.     

Effect of irrelevant differences as a function of the relations between relevant and irrelevant dimensions in the same-different task.

The effects of irrelevant differences as a function of the relations between relevant and irrelevant dimensions in the same–different task were examined. Form, size, and orientation were used as task conditions in Experiment 1, and form, size, and color were used in Experiment 2. In each experiment, 6 subjects were instructed to report same or different according to a relevant dimension, irrespective of two irrelevant dimensions. In Experiment 3, the degree of integrality was examined in all the combinations of dimensions involved, in the restricted-classification task. The results of the three experiments suggested that (a) effects of irrelevant differences depended on the degree of integrality between relevant and irrelevant dimensions, and (b) two irrelevant dimensions were processed by the subjects serially. Neither the relevance rechecking model (Miller & Bauer, 1981) nor the response competition model (e.g., Williams, 1974) alone could explain all the types of effects of irrelevant dimensions obtained in this study. Instead, a modified relevance rechecking model, in which the degree of integrality was introduced to the original relevance rechecking model, could predict and explain all types of effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing of an irrelevant location dimension as a function of the relevant stimulus dimension.

The effect of an irrelevant location dimension on choice reactions to the relevant stimulus dimension was examined. Exp 1 used variations of the spatial Stroop task and the Simon task that differed in whether the relevant dimension (location name or color) was similar to the irrelevant location dimension. Congruity of the stimulus dimensions and stimulus–response (S–R) mapping had additive effects in the Simon task but overadditive effects in the Stroop task. Exps 2–4 showed that each pattern could be obtained for both tasks, suggesting that dimensional similarity is not crucial; overadditivity occurred only when stimulus identification was prolonged. Results can be interpreted in terms of the relative timing of activation for the relevant and irrelevant information, if it is assumed that the activation function for irrelevant location varies across different S–R mappings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some factors that determine the influence of a stimulus that is irrelevant to a discrimination.

In 5 autoshaping experiments pigeons received 3 stimuli, A, B, and C, for a discrimination in which food was presented after the simultaneous compounds AC and BC, but not after the simultaneous compound ABC. The ease with which this discrimination was mastered was facilitated by presenting C continuously throughout each session (Experiment 1), by presenting C by itself for nonreinforced trials (Experiment 2), and by pairing C by itself consistently with food (Experiment 3). Presenting C by itself and pairing it with food according to a partial reinforcement schedule had no significant influence on the acquisition of the discrimination (Experiments 4 and 5). The results are consistent with a configural theory of associative learning that suggests that experience with a stimulus alters its salience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-response compatibility and the Simon effect: Toward an empirical clarification.

Perceptual accounts attribute the Simon effect to the correlation between relevant stimulus feature and response location (e.g., T. Hasbroucq & Y. Guiard, 1991). This account is questioned, and it is demonstrated that a Simon effect can be obtained without a stimulus–response correlation (Experiment 1). Experiments 2 and 3 replicated this finding and showed that the relative size of stimuli and response labels and temporal overlap of warning signal and stimulus cannot account for why the effect was absent in Hasbroucq and Guiard's study. However, no Simon effect occurred in a close replication of Hasbroucq and Guiard's original experiment (Experiment 4). Participants' reports suggested that this was due to a special stimulus-coding strategy, and in fact, the effect reappeared with a slightly modified stimulus display (Experiment 5). These results provide strong evidence against a perceptual approach to the Simon effect and support response-related views instead. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Salient-features coding in the translation between orthogonal stimulus and response dimensions.

Stimulus-response compatibility effects typically are attributed to translation processes. However, studies of compatibility effects obtained with orthogonal stimulus and response arrangements have attributed such effects to mechanisms other than translation processes. The present study evaluated whether recent theoretical advances regarding cognitive coding render a translation-based account viable for orthogonal stimulus-response arrangements. Across all experiments, a preference was shown for the mapping of up-to-right and down-to-left. This preference occurred regardless of whether the response set was manual or vocal, unimanual or bimanual, and whether the stimuli were spatial or symbolic. The results are consistent with the general literature on stimulus-response compatibility, which places the locus of most compatibility phenomena in translation processes. Moreover, the results support the notion that these translation processes operate according to a salient-features coding principle. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus–response compatibility as a function of stimulus code and response modality.

The concept of stimulus-response compatibility can be differentiated into set-level and element-level compatibility. The relation between these 2 types of compatibility was examined by varying stimulus code (spatial or verbal) and response modality (manual or vocal) in 2-choice tasks that used left-right stimuli and left-right responses. Element-level compatibility was an increasing function of set-level compatibility and larger for verbal than for spatial stimuli. The positive relation between set- and element-level compatibility was due to differences for the congruent mapping but not the incongruent mapping. The results can be characterized in terms of (a) a continuum along which the relative compatibility of the responses with spatial and verbal stimuli varies and (b) a dual-route conception of response selection in which a direct, or automatic, route is involved only when a congruent mapping is in effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Neuronal correlates of sensorimotor association in stimulus–response compatibility.

Neuronal mechanisms underlying stimulus–response (S-R) associations in S-R compatibility tasks were identified in 2 experiments with monkeys. Visual stimuli were presented on the left and right calling for left–right movements under congruent and incongruent S-R mapping instructions. High- and low-pitched tones calling for left–right movements were presented to the left and right ear, and the stimulus side was irrelevant. Single neurons sensitive to the S-R mapping rule were found in the primary motor cortex. The large overlap between the neuronal populations sensitive to the stimulus side, the S-R mapping rule, and the response side, respectively, is consistent with the idea that sensory-to-motor transformation is a continuous rather than a discrete process. Results partly support the hypothesis that the increase in reaction time with incongruent mapping is caused by the automatic activation of the congruent, but erroneous, response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences in the associability of relevant and irrelevant stimuli.

Pigeons in two experiments were first trained with a set of simple discriminations of the form AX+ CX?, BY+ DY? where A, B, C, and D were relevant, and belonged to one dimension, and X and Y were irrelevant and belonged to a different dimension. They were then tested with a discrimination of the form AX+ AY? BX?. The experiments revealed that the discrimination between AX+ and BX? was acquired more readily than between AX+ and AY?, which indicates that the original training resulted in the associability of the relevant stimuli being greater than that of the irrelevant stimuli. Experiment 2 revealed that the status of other stimuli from the two dimensions influenced these changes in associability. The associability of X and Y was enhanced by making other stimuli from the same dimension relevant, and the associability of A and B was reduced by making other stimuli from the same dimension irrelevant. The associability of the stimuli is attributed to the attention they are paid. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constant irrelevant cues and stimulus generalization in monkeys.

Trained 14 jungle-born female pigtailed monkeys to criterion on 2 concurrently presented 4-choice object discriminations. In 1 problem form was relevant and color constant irrelevant; in the other, color was relevant and form constant irrelevant. Following training, Ss were given transfer tests with a 4-choice setting consisting of the 2 formerly rewarded objects, a 3rd object composed of the rewarded relevant features of the color and form discriminations, and a 4th object constructed from the 2 constant irrelevant color and form features. Ss consistently chose the previously rewarded objects during transfer, but of the new objects, almost always chose the object constructed of relevant features. A number of models for discrimination learning are considered in the light of these data. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motor activation from visible speech: Evidence from stimulus response compatibility.

In speech perception, phonetic information can be acquired optically as well as acoustically. The motor theory of speech perception holds that motor control structures are involved in the processing of visible speech, whereas perceptual accounts do not make this assumption. Motor involvement in speech perception was examined by showing participants response-irrelevant movies of a mouth articulating /bΛ/ or /dΛ/ and asking them to verbally respond with either the same or a different syllable. The letters "Ba" and "Da" appeared on the speaker's mouth to indicate which response was to be performed. A reliable interference effect was observed. In subsequent experiments, perceptual interference was ruled out by using response-unrelated imperative stimuli and by preexposing the relevant stimulus information. Further, it was demonstrated that simple directional features (opening and closing) do not account for the effect. Rather, the present study provides evidence for the view that visible speech is processed up to a late, response-related processing stage, as predicted by the motor theory of speech perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress affects the selection of relevant from irrelevant stimuli.

Two experiments were used to examine the effects of stress on latent inhibition (LI; poorer learning with a previously exposed irrelevant stimulus rather than a novel stimulus). In Experiment 1, stress was induced in college students by threatening participants' self-esteem with a difficult number series completion test that was related to intelligence. In Experiment 2, the participants were job seekers who were either informed or not that the LI test was part of the selection process. In both experiments, LI was attenuated in high- as compared with low-stressed participants. The results suggest that stress and/or anxiety impairs the inhibition of irrelevant-preexposed stimuli. Implications for understanding the impaired selective attentional processes in schizophrenia and schizotypy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Simon effect and its reversal in three-choice Hedge and Marsh tasks: Evidence for irrelevant stimulus-response compatibility and stimulus congruity.

In 2-choice A. Hedge and N. W. A. Marsh (1975) tasks or S. Komblum's (1992) Type-5 ensembles, irrelevant stimulus-response compatibility (SRC), logical recoding, display control arrangement correspondence (DCQ, and stimulus congruity are confounded. By using 3 response alternatives and both compatible and incompatible stimulus-response mappings, irrelevant SRC was pitted against logical recoding and both of them were disentangled from DCC and stimulus congruity. By varying response labels on a trial-by-trial basis and using different stimuli and responses, DCC and stimulus congruity were decoupled. Results from 4 experiments showed that neither logical recoding nor DCC contributes to the Simon effect and its reversal. Irrelevant SRC and stimulus congruity are necessary but neither is sufficient to account for the Simon effect and its reversal. A connectionist model of compatibility incorporating both irrelevant SRC and stimulus congruity appears to account for the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explanation of rewards that do not reduce tissue needs.

Evaluates theories offered for the variety of non-need-reducing stimuli which elicit the organism's interaction and serve as rewards including the theoretical analyses of D. Berlyne, W. Dember and R. Earl, D. Fiske and S. Maddi, H. Fowler, M. Glanzer, A. Jones, D. McClelland and R. Clark, K. Montgomery, A. Myers and H. Miller, D. Premack, and F. Sheffield. Some of the conceptual, empirical, and methodological issues, which seem most basic at this time for testing and extending these theories, are discussed. (126 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Question asking: To know that you do not know is not enough.

Effects of prior knowledge on question asking were examined. Fifth graders with little or much prior knowledge had to indicate the meaning of a set of words. Pupils could (a) not ask a question, (b) ask a global question, or (c) ask a specific question. In Study 1, prior knowledge significantly affected the number of questions asked and the pragmatic significance of the questions. In Study 2, selection was contrasted with production of questions. Pupils with little prior knowledge asked fewer specific questions and more global questions in production. The pragmatic significance of the questions was lower for all pupils in production. The pupils' questions were found wanting in information-gathering and communicative qualities. In Study 2, asking for "provisional answers" in advance of question asking strongly stimulated question asking. It presumably enhances commitment, stimulates monitoring, and alleviates social constraints in asking questions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional state and the use of stimulus dimensions in judgment.

Previous studies have demonstrated that, when they are emotional, individuals are more likely to attend to emotional stimuli. However, such work has not established that individuals attend to the emotional dimensions of complex stimuli or that such changes in focus of attention affect judgments. In the present experiments a multidimensional scaling analysis was used to assess the weights that happy, sad, and neutral-emotion participants gave to emotional and nonemotional dimensions of face stimuli in judgments of similarity. Compared to neutral-emotion participants, those in emotional states gave more weight to the emotional dimension of the faces, less weight to other face dimensions, and rated pairs of faces that expressed the same emotion as more similar. Emotion-congruent dimension use was also observed in one experiment. Results are discussed with respect to emotional response categories (P. M. Niedenthal & J. B. Halberstadt, 1995), the tendency for stimuli to cohere as categories on the basis of the emotional response they elicit in the perceiver. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Repetition effects with categorizable stimulus and response sets.

The repetition effect refers to the finding that reaction times (RTs) are faster on trial n when the stimulus presented and/or the response required is the same as on trial n?–?1 than when it is different. Five experiments examined the importance of stimulus features and response features in obtaining the repetition effect. Exp 1 demonstrated a need for the stimuli to be categorically mapped to responses for a response repetition effect to be observed. Exps 2–5 showed that the repetition effect can be obtained across responding hands when spatial information (Exps 2 and 4) or finger information (Exps 2 and 5) is consistent across hands but not when these sources of information are eliminated (Exp 3). The results are in agreement with expectations developed from salient-features coding and with the inclusive links hypothesis proposed by H. Pashler and G. Baylis (1991). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pheochromocytomas that do not accumulate metaiodobenzylguanidine: localization with PET and administration of FDG

Many imaging methods can be used to detect pheochromocytoma, but some tumors are not detected with conventional modalities. To explore the possible usefulness of positron emission tomography (PET) after administration of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) to localize pheochromocytoma in patients with false-negative scintigrams obtained after administration of metaiodobenzylguanidine (MIBG), FDG was administered and PET was performed in two adult patients with pheochromocytomas that had never been localized despite administration of MIBG. In both patients, images were obtained dynamically for 50 minutes; then a limited truncal sequence was performed. PET enabled correct localization of the tumors. In patient 1, a tumor that had not been detected for 21 years was localized in the middle mediastinum; in patient 2, a pheochromocytoma was detected in the right adrenal gland. PET performed after administration of FDG may be useful for localization of pheochromocytomas that do not accumulate MIBG.