PsyResearch
ψ   Psychology Research on the Web   



Couples needed for online psychology research


Help us grow:




Journal of Experimental Psychology: Human Perception and Performance - Vol 39, Iss 2

Random Abstract
Quick Journal Finder:
Journal of Experimental Psychology: Human Perception and Performance The Journal of Experimental Psychology: Human Perception and Performance publishes studies on perception, control of action, and related cognitive processes.
Copyright 2013 American Psychological Association
  • Matching voice and face identity from static images.
    Previous research has suggested that people are unable to correctly choose which unfamiliar voice and static image of a face belong to the same person. Here, we present evidence that people can perform this task with greater than chance accuracy. In Experiment 1, participants saw photographs of two, same-gender models, while simultaneously listening to a voice recording of one of the models pictured in the photographs and chose which of the two faces they thought belonged to the same model as the recorded voice. We included three conditions: (a) the visual stimuli were frontal headshots (including the neck and shoulders) and the auditory stimuli were recordings of spoken sentences; (b) the visual stimuli only contained cropped faces and the auditory stimuli were full sentences; (c) we used the same pictures as Condition 1 but the auditory stimuli were recordings of a single word. In Experiment 2, participants performed the same task as in Condition 1 of Experiment 1 but with the stimuli presented in sequence. Participants also rated the model's faces and voices along multiple “physical” dimensions (e.g., weight,) or “personality” dimensions (e.g., extroversion); the degree of agreement between the ratings for each model's face and voice was compared to performance for that model in the matching task. In all three conditions, we found that participants chose, at better than chance levels, which faces and voices belonged to the same person. Performance in the matching task was not correlated with the degree of agreement on any of the rated dimensions. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Visual coding of human bodies: Perceptual aftereffects reveal norm-based, opponent coding of body identity.
    Despite the discovery of body-selective neural areas in occipitotemporal cortex, little is known about how bodies are visually coded. We used perceptual adaptation to determine how body identity is coded. Brief exposure to a body (e.g., anti-Rose) biased perception toward an identity with opposite properties (Rose). Moreover, the size of this aftereffect increased with adaptor extremity, as predicted by norm-based, opponent coding of body identity. A size change between adapt and test bodies minimized the effects of low-level, retinotopic adaptation. These results demonstrate that body identity, like face identity, is opponent coded in higher-level vision. More generally, they show that a norm-based multidimensional framework, which is well established for face perception, may provide a powerful framework for understanding body perception. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Eye movement control during scene viewing: Immediate effects of scene luminance on fixation durations.
    Recent research on eye movements during scene viewing has primarily focused on where the eyes fixate. But eye fixations also differ in their durations. Here we investigated whether fixation durations in scene viewing are under the direct and immediate control of the current visual input. Subjects freely viewed photographs of scenes in preparation for a later memory test while their eye movements were recorded. Using a novel scene degradation paradigm based on a saccade-contingent display change method, scenes were reduced in luminance during saccades ending in critical fixations. Results from two experiments showed that the durations of the critical fixations were immediately affected by scene luminance, with a monotonic relationship between luminance reduction and fixation duration. The results are the first to demonstrate that fixation durations in scene viewing are immediately influenced by the ease of processing of the image currently in view. These results are consistent with the CRISP (a timer-Controlled Random-Walk with Inhibition for Saccade Planning) computational model of saccade generation in scenes, proposing that difficulty in moment-by-moment visual and cognitive processing of the scene modulates fixation durations. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Divergent effects of cognitive load on quiet stance and task-linked postural coordination.
    Performing a cognitive task while maintaining upright stance can lead to increased or reduced body sway depending on tasks and experimental conditions. Because greater sway is commonly taken to indicate loosened postural control, and vice versa, the precise impact of cognitive load on postural stability has remained unclear. In much of the large literature on posture–cognition dual tasking, the assigned postural task is to simply maintain stance (so-called “quiet standing”). This contrasts with quotidian use of postural coordination to maintain balance while also facilitating suprapostural sensorimotor tasks. In this study, healthy young participants either maintained quiet stance or carried out a visuopostural alignment task while performing a spatial, nonspatial, or no additional cognitive task. Body sway increased during both cognitive tasks while quiet standing, as is often observed, but not while performing the visuopostural alignment task. This result is not consistent with the commonly invoked competition between tasks for limited processing resources. It suggests that constraints placed on posture control by suprapostural task goals may significantly alter interactions between posture control and cognitive tasks, and that dual-task results obtained under quiet standing conditions may not generalize to postural control in everyday task conditions. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Perceiving group behavior: Sensitive ensemble coding mechanisms for biological motion of human crowds.
    Many species, including humans, display group behavior. Thus, perceiving crowds may be important for social interaction and survival. Here, we provide the first evidence that humans use ensemble-coding mechanisms to perceive the behavior of a crowd of people with surprisingly high sensitivity. Observers estimated the headings of briefly presented crowds of point-light walkers that differed in the number and headings of their members (i.e., people in differently sized crowds had identical or increasingly variable directions of walking). We found that observers rapidly pooled information from multiple walkers to estimate the heading of a crowd. This ensemble code was precise; observer's perceived the behavior of a crowd better than the behavior of an individual. We also showed that this pooling provided tolerance against crowd variability and may cause a chaotic group to cohere into a unified Gestalt. Sensitive perception of a crowd's behavior required integration of human form and motion, suggesting that the ensemble code was generated in high-level visual areas. Overall, these mechanisms may reflect the prevalence of crowd behavior in nature and a social benefit for perceiving crowds as unified entities. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Collective enumeration.
    Many joint decisions in everyday life (e.g., Which bar is less crowded?) depend on approximate enumeration, but very little is known about the psychological characteristics of counting together. Here we systematically investigated collective approximate enumeration. Pairs of participants made individual and collective enumeration judgments in a 2-alternative forced-choice task and when in disagreement, they negotiated joint decisions via verbal communication and received feedback about accuracy at the end of each trial. The results showed that two people could collectively count better than either one alone, but not as well as expected by previous models of collective sensory decision making in more basic perceptual domains (e.g., luminance contrast). Moreover, such collective enumeration benefited from prior, noninteractive practice showing that social learning of how to combine shared information about enumeration required substantial individual experience. Finally, the collective context had a positive but transient impact on an individual's enumeration sensitivity. This transient social influence may be explained as a motivational factor arising from the fact that members of a collective must take responsibility for their individual decisions and face the consequences of their judgments. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Changing perspective: Zooming in and out during visual search.
    Laboratory studies of visual search are generally conducted in contexts with a static observer vantage point, constrained by a fixation cross or a headrest. In contrast, in many naturalistic search settings, observers freely adjust their vantage point by physically moving through space. In two experiments, we evaluate behavior during free vantage point (FVP) search, using observer-controlled zooming to simulate movement toward or away from search objects. We focus on scope fluctuations—repeated reversals in the direction of zooming during search. We found increased fluctuation when search items were sparse (Experiment 1) or of mixed size (Experiment 2). We propose that during FVP search, observers attempt to maximize the number of simultaneously discriminable items. Scope fluctuations emerge when maximizing does not enable simultaneous access to all search items, or when observers become disoriented in the search environment, necessitating repeated switches to a broad scope to reorient. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Motor and executive control in repetitive timing of brief intervals.
    We investigated the causal role of executive control functions in the production of brief time intervals by means of a concurrent task paradigm. To isolate the influence of executive functions on timing from motor coordination effects, we dissociated executive load from the number of effectors used in the dual task situation. In 3 experiments, participants produced isochronous intervals ranging from 524 to 2,000 ms with either the left or the right hand. The concurrent task consisted of the production of either a pseudorandom (high cognitive load) or a simple repeated (low cognitive load) spatial sequence of key presses, while also maintaining a regular temporal sequence. This task was performed with either a single hand (unimanual) or with both hands simultaneously (bimanual). Interference in terms of increased timing variability caused by the concurrent task was observed only in the bimanual condition. We verified that motor coordination in bimanual tasks alone could not account for the interference. Timing interference only appeared when (a) more than 1 effector was involved and (b) there were simultaneous task demands that recruited executive functions. Task interference was not seen if only 1 of these 2 conditions was met. Thus, our results suggest that executive functions are not directly involved in motor timing, but can indirectly affect timing performance when they are required to schedule complex motor coordination. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Complex dynamic scene perception: Effects of attentional set on perceiving single and multiple event types.
    Three experiments measured the efficiency of monitoring complex scenes composed of changing objects, or events. All events lasted about 4 s, but in a given block of trials, could be of a single type (single task) or of multiple types (multitask, with a total of four event types). Overall accuracy of detecting target events amid distractors was higher for single event types relative to multiple types. Multiple event types were processed reasonably well when each event type was restricted to its own region, and much worse when event types were mixed in location. In most task conditions, observers reached an optimal level of performance (optimal attentional set). After one target was identified, performance for other targets dropped markedly and then recovered to optimal levels. However, set was not optimized when task locations were intermixed. The results support the idea that attentional set determines the efficiency of event perception in complex scenes. Although single event set was most efficient, there can be a reasonably efficient set for multiple event types. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Keeping timbre in mind: Working memory for complex sounds that can't be verbalized.
    Properties of auditory working memory for sounds that lack strong semantic associations and are not readily verbalized or sung are poorly understood. We investigated auditory working memory capacity for lists containing 2−6 easily discriminable abstract sounds synthesized within a constrained timbral space, at delays of 1–6 s (Experiment 1), and the effect of greater perceptual variability among list items on capacity estimates at delays of 1–6 s (Experiment 2). Working memory capacity estimates of 1−2 items were found in all conditions and increased significantly as the perceptual variability among the list items increased. Nonetheless, the capacity estimates were smaller than the commonly observed average working memory capacity limit of 3−5 items. Decay profiles in both experiments were comparable with those previously reported in the verbal and auditory working memory literature. The results help define boundary conditions on capacity estimates for nonverbalizable timbres that lack strong long-term memory associations. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Investigating perfect timesharing: The relationship between IM-compatible tasks and dual-task performance.
    Why are dual-task costs reduced with ideomotor (IM) compatible tasks (Greenwald & Shulman, 1973; Lien, Proctor & Allen, 2002)? In the present experiments, we first examine three different measures of single-task performance (pure single-task blocks, mixed blocks, and long stimulus onset asynchrony [SOA] trials in dual-task blocks) and two measures of dual-task performance (simultaneous stimulus presentation blocks and simultaneous stimulus presentation trials in blocks with mixed SOAs), and show that these different measures produce different estimates of the cost. Next we examine whether the near elimination of costs can be explained by assuming that one or both of the tasks bypasses capacity-limited central operations. The results indicate that both tasks must be IM-compatible to nearly eliminate the dual-task costs, suggesting that the relationship between the tasks plays a critical role in overlapping performance. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Converging evidence for control of color–word Stroop interference at the item level.
    Prior studies have shown that cognitive control is implemented at the list and context levels in the color–word Stroop task. At first blush, the finding that Stroop interference is reduced for mostly incongruent items as compared with mostly congruent items (i.e., the item-specific proportion congruence [ISPC] effect) appears to provide evidence for yet a third level of control, which modulates word reading at the item level. However, evidence to date favors the view that ISPC effects reflect the rapid prediction of high-contingency responses and not item-specific control. In Experiment 1, we first show that an ISPC effect is obtained when the relevant dimension (i.e., color) signals proportion congruency, a problematic pattern for theories based on differential response contingencies. In Experiment 2, we replicate and extend this pattern by showing that item-specific control settings transfer to new stimuli, ruling out alternative frequency-based accounts. In Experiment 3, we revert to the traditional design in which the irrelevant dimension (i.e., word) signals proportion congruency. Evidence for item-specific control, including transfer of the ISPC effect to new stimuli, is apparent when 4-item sets are employed but not when 2-item sets are employed. We attribute this pattern to the absence of high-contingency responses on incongruent trials in the 4-item set. These novel findings provide converging evidence for reactive control of color–word Stroop interference at the item level, reveal theoretically important factors that modulate reliance on item-specific control versus contingency learning, and suggest an update to the item-specific control account (Bugg, Jacoby, & Chanani, 2011). (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Children's face identity representations are no more view specific than those of adults.
    Face recognition performance improves during childhood, not reaching adult levels until late adolescence, yet the source of this improvement is unclear. Recognition of faces across changes in viewpoint appears particularly slow to develop. Poor cross-view recognition suggests that children's face representations may be more view specific than those of adults and is consistent with arguments that extensive experience with faces may be required to form representations that are robust to view changes. We conducted the first direct test of the view specificity of children's face representations by using face aftereffects to investigate whether children's face aftereffects transfer across changes in viewpoint. Using both the figural aftereffect (E1) and the identity aftereffect (E2) we showed that 8-year-old children's aftereffects transferred across substantial changes in viewpoint and that children did not differ from adults in the amount of transfer across viewpoint. These results suggest that children's coding of identity is no more view specific than that of adults and are consistent with a growing body of evidence indicating that the key perceptual mechanisms of face recognition emerge early in life. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Perceiving and reenacting spatiotemporal characteristics of walking sounds.
    Many studies have examined the processes involved in recognizing types of human action through sound, but little is known about whether the physical characteristics of an action (such as kinetic and kinematic parameters) can be perceived and imitated from sound. Twelve young healthy adults listened to recordings of footsteps on a gravel path taken from walks of different stride lengths (SL) and cadences. In 1 protocol, participants performed a real-time reenactment of the walking action depicted in a sound sample. Second, participants listened to 2 different sound samples and discriminated differences in SL. In a 2nd experiment, these procedures were repeated using synthesized sounds derived from the kinetic interactions between the foot and walking surface. A 3rd experiment examined the influence of altered cadence on participants' ability to discriminate changes in SL. Participants significantly adapted their own SL and cadence according to those depicted in both real and synthesized sounds (p <.01). However, although participants accurately discriminated between large changes in SL, these perceptions were heavily influenced by temporal factors, that is, when cadence changed between samples. These findings show that spatial attributes of action sounds can be both mimicked and discriminated, even when only basic kinetic interactions present within the action are specified. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • On the anisotropy of perceived ground extents and the interpretation of walked distance as a measure of perception.
    Two experiments are reported concerning the perception of ground extent to discover whether prior reports of anisotropy between frontal extents and extents in depth were consistent across different measures (visual matching and pantomime walking) and test environments (outdoor environments and virtual environments). In Experiment 1 it was found that depth extents of up to 7 m are indeed perceptually compressed relative to frontal extents in an outdoor environment, and that perceptual matching provided more precise estimates than did pantomime walking. In Experiment 2, similar anisotropies were found using similar tasks in a similar (but virtual) environment. In both experiments pantomime walking measures seemed to additionally compress the range of responses. Experiment 3 supported the hypothesis that range compression in walking measures of perceived distance might be due to proactive interference (memory contamination). It is concluded that walking measures are calibrated for perceived egocentric distance, but that pantomime walking measures may suffer range compression. Depth extents along the ground are perceptually compressed relative to frontal ground extents in a manner consistent with the angular scale expansion hypothesis. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • The development of individuation in autism.
    Evidence suggests that people with autism rely less on holistic visual information than typical adults. The current studies examine this by investigating core visual processes that contribute to holistic processing—namely, individuation and element grouping—and how they develop in participants with autism and typically developing (TD) participants matched for age, IQ, and gender. Individuation refers to the ability to “see” approximately four elements simultaneously; grouping elements can modify how many elements can be individuated. We examined these processes using two well-established paradigms, rapid enumeration and multiple object tracking (MOT). In both tasks, a performance limit of four elements in typical adults is thought to reflect individuation capacity. Participants with autism displayed a smaller individuation capacity than TD controls, regardless of whether they were enumerating static elements or tracking moving ones. To manipulate the holistic information available via element grouping, elements were arranged into a design in rapid enumeration, or moved together in MOT. Performance in participants with autism was affected to a similar degree as TD participants by element grouping, whether the manipulation helped or hurt performance, consistent with evidence that some types of gestalt/grouping information are processed typically in autism. There was substantial development from childhood to adolescence in the speed of individuation in those with autism, but not from adolescence to adulthood, a pattern distinct from TD participants. These results reveal how core visual processes function in autism, and provide insight into the architecture of vision (i.e., individuation appears distinct from visual strengths in autism, such as visual search). (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Seeing stems everywhere: Position-independent identification of stem morphemes.
    There is broad consensus that printed complex words are identified on the basis of their constituent morphemes. This fact raises the issue of how the word identification system codes for morpheme position, hence allowing it to distinguish between words like overhang and hangover, and to recognize that preheat is a word, whereas heatpre is not. Recent data have shown that suffixes are identified as morphemes only when they occur at the end of letter strings (Crepaldi, Rastle, & Davis, 2010, “Morphemes in Their Place: Evidence for Position-Specific Identification of Suffixes,” Memory & Cognition, 38, 312–321), which supports the general proposal that the word identification system is sensitive to morpheme positional constraints. This proposal leads to the prediction that the identification of free stems should occur in a position-independent fashion, given that free stems can occur anywhere within complex words (e.g., overdress and dresser). In Experiment 1, we show that the rejection time of transposed-constituent pseudocompounds (e.g., moonhoney) is longer than that of matched control nonwords (e.g., moonbasin), suggesting that honey and moon are identified within moonhoney, and that these morpheme representations activate the representation for the word honeymoon. In Experiments 2 and 3, we demonstrate that the masked presentation of transposed-constituent pseudocompounds (e.g., moonhoney) facilitates the identification of compound words (honeymoon). In contrast, monomorphemic control pairs do not produce a similar pattern (i.e., rickmave did not prime maverick), indicating that the effect for moonhoney pairs is genuinely morphological in nature. These results demonstrate that stem representations differ from affix representations in terms of their positional constraints, providing a challenge to all existing theories of morphological processing. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Parafoveal–foveal overlap can facilitate ongoing word identification during reading: Evidence from eye movements.
    Readers continuously receive parafoveal information about the upcoming word in addition to the foveal information about the currently fixated word. Previous research (Inhoff, Radach, Starr, & Greenberg, 2000) showed that the presence of a parafoveal word that was similar to the foveal word facilitated processing of the foveal word. We used the gaze-contingent boundary paradigm (Rayner, 1975) to manipulate the parafoveal information that subjects received before or while fixating a target word (e.g., news) within a sentence. Specifically, a reader's parafovea could contain a repetition of the target (news), a correct preview of the posttarget word (once), an unrelated word (warm), random letters (cxmr), a nonword neighbor of the target (niws), a semantically related word (tale), or a nonword neighbor of that word (tule). Target fixation times were significantly lower in the parafoveal repetition condition than in all other conditions, suggesting that foveal processing can be facilitated by parafoveal repetition. We present a simple model framework that can account for these effects. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Cognitive control of auditory distraction: Impact of task difficulty, foreknowledge, and working memory capacity supports duplex-mechanism account.
    The influence of top-down cognitive control on 2 putatively distinct forms of distraction was investigated. Attentional capture by a task-irrelevant auditory deviation (e.g., a female-spoken token following a sequence of male-spoken tokens)—as indexed by its disruption of a visually presented recall task—was abolished when focal-task engagement was promoted either by increasing the difficulty of encoding the visual to-be-remembered stimuli (by reducing their perceptual discriminability; Experiments 1 and 2) or by providing foreknowledge of an imminent deviation (Experiment 2). In contrast, distraction from continuously changing auditory stimuli (“changing-state effect”) was not modulated by task-difficulty or foreknowledge (Experiment 3). We also confirmed that individual differences in working memory capacity—typically associated with maintaining task-engagement in the face of distraction—predict the magnitude of the deviation effect, but not the changing-state effect. This convergence of experimental and psychometric data strongly supports a duplex-mechanism account of auditory distraction: Auditory attentional capture (deviation effect) is open to top-down cognitive control, whereas auditory distraction caused by direct conflict between the sound and focal-task processing (changing-state effect) is relatively immune to such control. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Dyslexia and fluency: Parafoveal and foveal influences on rapid automatized naming.
    The ability to coordinate serial processing of multiple items is crucial for fluent reading but is known to be impaired in dyslexia. To investigate this impairment, we manipulated the orthographic and phonological similarity of adjacent letters online as dyslexic and nondyslexic readers named letters in a serial naming (RAN) task. Eye movements and voice onsets were recorded. Letter arrays contained target item pairs in which the second letter was orthographically or phonologically similar to the first letter when viewed either parafoveally (Experiment 1a) or foveally (Experiment 1b). Relative to normal readers, dyslexic readers were more affected by orthographic confusability in Experiment 1a and phonological confusability in Experiment 1b. Normal readers were slower to process orthographically similar letters in Experiment 1b. Findings indicate that the phonological and orthographic processing problems of dyslexic readers manifest differently during parafoveal and foveal processing, with each contributing to slower RAN performance and impaired reading fluency. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • The role of clarity and blur in guiding visual attention in photographs.
    Visual artists and photographers believe that a viewer's gaze can be guided by selective use of image clarity and blur, but there is little systematic research. In this study, participants performed several eye-tracking tasks with the same naturalistic photographs, including recognition memory for the entire photo, as well as recognition memory and personality ratings for individual people in the photos (Experiments 1–3). The results showed that fixations occurred more rapidly and frequently to a local region of clarity than to a comparable blurred region in all tasks, independent of the content of the photo in the local region, and even under instructions to look equally at both regions. However, this bias was reversed when the content of the photos was no longer task-relevant. In Experiment 4, participants located target regions defined by either clarity or blur. Fixations and manual responses were faster for blurred than for sharp targets. These findings imply that the saliency of both image clarity and image blur depends on viewers' goals. Focusing on photo content prioritizes regions of clarity whereas focusing on photo quality prioritizes attention to regions of blur. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Evidence for interaction between the stop signal and the Stroop task conflict.
    Performance of the Stroop task reflects two conflicts—informational (between the incongruent word and ink color) and task (between relevant color naming and irrelevant word reading). The task conflict is usually not visible, and is only seen when task control is damaged. Using the stop-signal paradigm, a few studies demonstrated longer stop-signal reaction times for incongruent trials than for congruent trials. This indicates interaction between stopping and the informational conflict. Here we suggest that “zooming in” on task-control failure trials will reveal another interaction—between stopping and task conflict. To examine this suggestion, we combined stop-signal and Stroop tasks in the same experiment. When participants' control failed and erroneous responses to a stop signal occurred, a reverse facilitation emerged in the Stroop task (Experiment 1) and this was eliminated using methods that manipulated the emergence of the reverse facilitation (Experiment 2). Results from both experiments were replicated when all stimuli were used in the same task (Experiment 3). In erroneous response trials, only the task conflict increased, not the informational conflict. These results indicate that task conflict and stop-signal inhibition share a common control mechanism that is dissociable from the control mechanism activated by the informational conflict. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source

  • Dissociation of S-R compatibility and Simon effects with mixed tasks and mappings.
    Binary-choice reactions are typically faster when the stimulus location corresponds with that of the response than when it does not. This advantage of spatial correspondence is known as the stimulus-response compatibility (SRC) effect when the mapping of stimulus location, as the relevant stimulus dimension, is varied to be compatible or incompatible with response location. It is called the Simon effect when stimulus location is task-irrelevant. The SRC effect is eliminated when compatible and incompatible spatial mappings are mixed within a trial block, and the Simon effect is eliminated when the Simon task is mixed with the SRC task with incompatible spatial mapping. Eliminations of both types have been attributed to suppression of an automatic response-activation route. We tested predictions of this suppression hypothesis for conditions in which the SRC and Simon tasks were intermixed and the spatial mappings on the SRC trials could be compatible or incompatible. In Experiment 1, the two tasks were equally likely, as were compatible and incompatible spatial mappings on SRC trials; in Experiment 2, the SRC or Simon task was more frequent; and, in Experiment 3, the compatible or incompatible location mapping for the SRC task was more frequent. The SRC effect was absent overall in all experiments, whereas the Simon effect was robust to the manipulations and showed the characteristic decrease across the reaction time (RT) distribution. This dissociation of effects implies that the automatic response-activation route is not suppressed in mixed conditions and suggests that mixing influences the SRC and Simon effects by different means. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
    Citation link to source



Back to top


Back to top