Flanker and Simon effects interact at the response selection stage

The present study aimed at investigating the processing stage underlying stimulus–stimulus (S–S) congruency effects by examining the relation of a particular type of congruency effect (i.e., the flanker effect) with a stimulus–response (S–R) spatial correspondence effect (i.e., the Simon effect). Experiment 1 used a unilateral flanker task in which the flanker also acted as a Simon-like accessory stimulus. Results showed a significant S–S Congruency × S–R Correspondence interaction: An advantage for flanker–response spatially corresponding trials was observed in target–flanker congruent conditions, whereas, in incongruent conditions, there was a noncorresponding trials' advantage. The analysis of the temporal trend of the correspondence effects ruled out a temporal-overlap account for the observed interaction. Moreover, results of Experiment 2, in which the flanker did not belong to the target set, demonstrated that this interaction cannot be attributed to perceptual grouping of the target–flanker pairs and referential coding of the target with respect to the flanker in the congruent and incongruent conditions, respectively. Taken together, these findings are consistent with a response selection account of congruency effects: Both the position and the task-related attribute of the flanker would activate the associated responses. In noncorresponding-congruent trials and corresponding-incongruent trials, this would cause a conflict at the response selection stage.     

Does crossmodal correspondence modulate the facilitatory effect of auditory cues on visual search?

The ??pip-and-pop effect?? refers to the facilitation of search for a visual target (a horizontal or vertical bar whose color changes frequently) among multiple visual distractors (tilted bars also changing color unpredictably) by the presentation of a spatially uninformative auditory cue synchronized with the color change of the visual target. In the present study, the visual stimuli in the search display changed brightness instead of color, and the crossmodal congruency between the pitch of the auditory cue and the brightness of the visual target was manipulated. When cue presence and cue congruency were randomly varied between trials (Experiment 1), both congruent cues (low-frequency tones synchronized with dark target states or high-frequency tones synchronized with bright target states) and incongruent cues (the reversed mapping) facilitated visual search performance equally, relative to a no-cue baseline condition. However, when cue congruency was blocked and the participants were informed about the pitch?Cbrightness mapping in the cue-present blocks (Experiment 2), performance was significantly enhanced when the cue and target were crossmodally congruent as compared to when they were incongruent. These results therefore suggest that the crossmodal congruency between auditory pitch and visual brightness can influence performance in the pip-and-pop task by means of top-down facilitation.     

Tactile selective attention and body posture: assessing the multisensory contributions of vision and proprioception

This study addressed the role of proprioceptive and visual cues to body posture during the deployment of tactile spatial attention. Participants made speeded elevation judgments (up vs. down) to vibrotactile targets presented to the finger or thumb of either hand, while attempting to ignore vibrotactile distractors presented to the opposite hand. The first two experiments established the validity of this paradigm and showed that congruency effects were stronger when the target hand was uncertain (Experiment 1) than when it was certain (Experiment 2). Varying the orientation of the hands revealed that these congruency effects were determined by the position of the target and distractor in external space, and not by the particular skin sites stimulated (Experiment 3). Congruency effects increased as the hands were brought closer together in the dark (Experiment 4), demonstrating the role of proprioceptive input in modulating tactile selective attention. This spatial modulation was also demonstrated when a mirror was used to alter the visually perceived separation between the hands (Experiment 5). These results suggest that tactile, spatially selective attention can operate according to an abstract spatial frame of reference, which is significantly modulated by multisensory contributions from both proprioception and vision.     

The interplay of bottom-up and top-down mechanisms in visual guidance during object naming

An ongoing issue in visual cognition concerns the roles played by low- and high-level information in guiding visual attention, with current research remaining inconclusive about the interaction between the two. In this study, we bring fresh evidence into this long-standing debate by investigating visual saliency and contextual congruency during object naming (Experiment 1), a task in which visual processing interacts with language processing. We then compare the results of this experiment to data of a memorization task using the same stimuli (Experiment 2). In Experiment 1, we find that both saliency and congruency influence visual and naming responses and interact with linguistic factors. In particular, incongruent objects are fixated later and less often than congruent ones. However, saliency is a significant predictor of object naming, with salient objects being named earlier in a trial. Furthermore, the saliency and congruency of a named object interact with the lexical frequency of the associated word and mediate the time-course of fixations at naming. In Experiment 2, we find a similar overall pattern in the eye-movement responses, but only the congruency of the target is a significant predictor, with incongruent targets fixated less often than congruent targets. Crucially, this finding contrasts with claims in the literature that incongruent objects are more informative than congruent objects by deviating from scene context and hence need a longer processing. Overall, this study suggests that different sources of information are interactively used to guide visual attention on the targets to be named and raises new questions for existing theories of visual attention.     

Vision of a pictorial hand modulates visual-tactile interactions

The participants in this study discriminated the position of tactile target stimuli presented at the tip or the base of the forefinger of one of the participants’ hands, while ignoring visual distractor stimuli. The visual distractor stimuli were presented from two circles on a display aligned with the tactile targets in Experiment 1 or orthogonal to them in Experiment 2. Tactile discrimination performance was slower and less accurate when the visual distractor stimuli were presented from incongruent locations relative to the tactile target stimuli (e.g., tactile target at the base of the finger with top visual distractor) highlighting a cross-modal congruency effect. We examined whether the presence and orientation of a simple line drawing of a hand, which was superimposed on the visual distractor stimuli, would modulate the cross-modal congruency effects. When the tactile targets and the visual distractors were spatially aligned, the modulatory effects of the hand picture were small (Experiment 1). However, when they were spatially misaligned, the effects were much larger, and the direction of the cross-modal congruency effects changed in accordance with the orientation of the picture of the hand, as if the hand picture corresponded to the participants’ own stimulated hand (Experiment 2). The results suggest that the two-dimensional picture of a hand can modulate processes maintaining our internal body representation. We also observed that the cross-modal congruency effects were influenced by the postures of the stimulated and the responding hands. These results reveal the complex nature of spatial interactions among vision, touch, and proprioception.     

视听刺激突显性对视觉主导效应的影响

本研究使用空间任务-转换范式,控制视、听刺激的突显性,探讨自下而上注意对视觉主导效应的影响。结果表明视、听刺激突显性显著地影响视觉主导效应,实验一中当听觉刺激为高突显性时,视觉主导效应显著减弱。实验二中当听觉刺激为高突显性并且视觉刺激为低突显性时,视觉主导效应进一步减弱但依然存在。结果支持偏向竞争理论,在跨通道视听交互过程中视觉刺激更具突显性,在多感觉整合过程中更具加工优势。     

Audiovisual semantic interference and attention: Evidence from the attentional blink paradigm

In the present study we investigate the role of attention in audiovisual semantic interference, by using an attentional blink paradigm. Participants were asked to make an unspeeded response to the identity of a visual target letter. This target letter was preceded at various SOAs by a synchronized audiovisual letter-pair, which was either congruent (e.g. hearing an “F” and viewing an “F”) or incongruent (e.g. hearing an “F” and viewing a “Z”). In Experiment 1, participants were asked to match the members of the audiovisual letter-pair. In Experiment 2, participants were asked to ignore the synchronized audiovisual letter-pairs altogether and only report the visual target. In Experiment 3, participants were asked to identify only one of the audiovisual letters (identify the auditory letter, and ignore the synchronized visual letter, or vice versa). An attentional blink was found in all three experiments indicating that the audiovisual letter-pairs were processed. However, a congruency effect on subsequent target detection was observed in Experiments 1 and 3, but not in Experiment 2. The results indicate that attention to the semantic contents of at least one modality is necessary to establish audiovisual semantic interference.     

Automatic auditory disambiguation of visual awareness

Multisensory integration can play a critical role in producing unified and reliable perceptual experience. When sensory information in one modality is degraded or ambiguous, information from other senses can crossmodally resolve perceptual ambiguities. Prior research suggests that auditory information can disambiguate the contents of visual awareness by facilitating perception of intermodally consistent stimuli. However, it is unclear whether these effects are truly due to crossmodal facilitation or are mediated by voluntary selective attention to audiovisually congruent stimuli. Here, we demonstrate that sounds can bias competition in binocular rivalry toward audiovisually congruent percepts, even when participants have no recognition of the congruency. When speech sounds were presented in synchrony with speech-like deformations of rivalling ellipses, ellipses with crossmodally congruent deformations were perceptually dominant over those with incongruent deformations. This effect was observed in participants who could not identify the crossmodal congruency in an open-ended interview (Experiment 1) or detect it in a simple 2AFC task (Experiment 2), suggesting that the effect was not due to voluntary selective attention or response bias. These results suggest that sound can automatically disambiguate the contents of visual awareness by facilitating perception of audiovisually congruent stimuli.     

Hand Position and Response Assignment Modulate the Activation of the Valence‐Space Conceptual Metaphor

Conceptual metaphor is ubiquitous in language and thought, as we usually reason and talk about abstract concepts in terms of more concrete ones via metaphorical mappings that are hypothesized to arise from our embodied experience. One pervasive example is the conceptual projection of valence onto space, which flexibly recruits the vertical and lateral spatial frames to gain structure (e.g., good is up ‐bad is down and good is right ‐bad is left ). In the current study, we used a valence judgment task to explore the role that exogenous bodily cues (namely response hand positions) play in the allocation of spatial attention and the modulation of conceptual congruency effects. Experiment 1 showed that congruency effects along the vertical axis are weakened when task conditions (i.e., the use of vertical visual cues, on the one hand, and the horizontal alignment of responses, on the other) draw attention to both the vertical and lateral axes making them simultaneously salient. Experiment 2 evidenced that the vertical alignment of participants’ hands while responding to the task—regardless of the location of their dominant hand—facilitates the judgment of positive and negative‐valence words, as long as participants respond in a metaphor–congruent manner (i.e., up responses are good and down responses are bad). Overall, these results support the claim that source domain representations are dynamically activated in response to the context and that bodily states are an integral part of that context.     

The congruency sequence effect emerges when the distracter precedes the target

The congruency effect in distracter interference tasks is typically smaller when the previous trial was incongruent as compared to congruent, suggesting the operation of a control process that minimizes the influence of irrelevant stimuli on behavior. However, both the conditions under which this congruency sequence effect (CSE) can be most easily observed without the typical learning and memory confounds, and the control process underlying it, remain controversial. We therefore tested a recent hypothesis that the CSE is most easily observed without the typical confounds when the distracter is processed before the target. In line with this “distracter head start” hypothesis, in Experiments 1 and 2 the CSE was larger when the distracter appeared before, relative to with, the target. Further, in Experiment 3, we observed a negative congruency effect after incongruent trials when a long interval separated the distracter from the target, consistent with a modulation of the response engendered by the distracter but not with a shift of attention toward the target. These findings reveal an important determinant of CSE magnitude when the typical learning and memory confounds are absent and new insights into the nature of control processes that contribute to this phenomenon.     

Peripheral spatial cues modulate spatial congruency effects: Analysing the “locus” of the cueing modulation

The spatial Stroop effect (slower left/right responses to left/right pointing arrows when they appear at spatially incongruent than at congruent locations) has often been used to examine the processing of irrelevant spatial information. We present data from two experiments in which the magnitude of such location-based interference is drastically reduced when the location of the arrow is precued by a spatial noninformative cue. The main aim of the present study was to clarify whether such modulation takes place at perceptual or at response-related stages of processing. First, we manipulated the spatial compatibility between the direction of the arrow and the location of the response so that each subject would respond with spatially compatible vs. incompatible key presses for each half of the experiment. We found that such manipulation did not have any effect on the standard reduction of the congruency effect by peripheral cues. In a second experiment, subjects made left/right key presses to directional arrows pointing bottom/up, which could appear equally often at left/right/bottom/up locations. In cued trials, we found a reduction of the congruency effect on the vertical axis (stimulus location-direction congruency), whereas congruency was unaffected by cueing in targets presented on the horizontal axis (stimulus-response location congruency). According to these results, we conclude that spatial noninformative cues modulate spatial Stroop interference by reducing the conflict between stimulus dimensions at perceptual- rather than motor-related stages of processing.     

Visual and auditory accessory stimulus offset and the Simon effect

We investigated the effect on the right and left responses of the disappearance of a task-irrelevant stimulus located on the right or left side. Participants pressed a right or left response key on the basis of the color of a centrally located visual target. Visual (Experiment 1) or auditory (Experiment 2) task-irrelevant accessory stimuli appeared or disappeared at locations to the right or left of the central target. In Experiment 1, responses were faster when onset or offset of the visual accessory stimulus was spatially congruent with the response. In Experiment 2, responses were again faster when onset of the auditory accessory stimulus and the response were on the same side. However, responses were slightly slower when offset of the auditory accessory stimulus and the response were on the same side than when they were on opposite sides. These findings indicate that transient change information is crucial for a visual Simon effect, whereas sustained stimulation from an ongoing stimulus also contributes to an auditory Simon effect.     

The neural correlates of orienting to walking direction in 6‐month‐old infants: An ERP study

The ability to detect social signals represents a first step to enter our social world. Behavioral evidence has demonstrated that 6‐month‐old infants are able to orient their attention toward the position indicated by walking direction, showing faster orienting responses toward stimuli cued by the direction of motion than toward uncued stimuli. The present study investigated the neural mechanisms underpinning this attentional priming effect by using a spatial cueing paradigm and recording EEG (Geodesic System 128 channels) from 6‐month‐old infants. Infants were presented with a central point‐light walker followed by a single peripheral target. The target appeared randomly at a position either congruent or incongruent with the walking direction of the cue. We examined infants' target‐locked event‐related potential (ERP) responses and we used cortical source analysis to explore which brain regions gave rise to the ERP responses. The P1 component and saccade latencies toward the peripheral target were modulated by the congruency between the walking direction of the cue and the position of the target. Infants' saccade latencies were faster in response to targets appearing at congruent spatial locations. The P1 component was larger in response to congruent than to incongruent targets and a similar congruency effect was found with cortical source analysis in the parahippocampal gyrus and the anterior fusiform gyrus. Overall, these findings suggest that a type of biological motion like the one of a vertebrate walking on the legs can trigger covert orienting of attention in 6‐month‐old infants, enabling enhancement of neural activity related to visual processing of potentially relevant information as well as a facilitation of oculomotor responses to stimuli appearing at the attended location.     

Congruency sequence effect in cross-task context: Evidence for dimension-specific modulation

The congruency sequence effect refers to a reduced congruency effect after incongruent trials relative to congruent trials. This modulation is thought to be, at least in part, due to the control mechanisms resolving conflict. The present study examined the nature of the control mechanisms by having participants perform two different tasks in an alternating way. When participants performed horizontal and vertical Simon tasks in Experiment 1A, and horizontal and vertical spatial Stroop task in Experiment 1B, no congruency sequence effect was obtained between the task congruencies. When the Simon task and spatial Stroop task were performed with different response sets in Experiment 2, no congruency sequence effect was obtained. However, in Experiment 3, in which the participants performed the horizontal Simon and spatial Stroop tasks with an identical response set, a significant congruency sequence effect was obtained between the task congruencies. In Experiment 4, no congruency sequence effect was obtained when participants performed two tasks having different task-irrelevant dimensions with the identical response set. The findings suggest inhibitory processing between the task-irrelevant dimension and response mode after conflict.     

Interlinguistic conflict: Word–word Stroop with first and second language colour words

The congruency (or Stroop) effect is a standard observation of slower and less accurate colour identification to incongruent trials (e.g. “red” in green) relative to congruent trials (e.g. “red” in red). This effect has been observed in a word–word variant of the task, when both the distracter (e.g. “red”) and target (e.g. “green”) are colour words. The Stroop task has also been used to study the congruency effect between two languages in bilinguals. The typical finding is that the congruency effect for L1 words is larger than that for L2 words. For the first time, the present report aims to extend this finding to a word–word variant of the bilingual Stroop task. In two experiments, French monolinguals performed a bilingual word–word Stroop task in which target word language, language match, and congruency between the distracter and target were manipulated. The critical manipulation across two experiments concerned the target language. In Experiment 1, target language was manipulated between groups, with either French (L1) or English (L2) target colour words. In Experiment 2, target words from both languages were intermixed. In both experiments, the congruency effect was larger when the distracter and target were from the same language (language match) than when they were from different languages (language mismatch). Our findings suggested that this congruency effect mostly depends on the language match between the distracter and target, rather than on a target language. It also did not seem to matter whether the language-mismatching distracter was or was not a potential response alternative. Semantic activation of languages in bilinguals and its implications on target identification are discussed.

     

情境特异比例一致变化对冲突效应的影响

采用Hedge和Marsh任务与比例一致性操纵相结合,分别以刺激的空间位置和形状作为比例一致操纵的情境线索,考察刺激-反应联结学习与注意调节在比例一致效应中的作用。结果发现,在情境比例一致操纵下,冲突效应的效应量受到比例一致操纵的影响产生反转。表明刺激-反应联结学习在情境特异比例一致效应中起到主要作用。     

Psychophysiological evidence of response conflict and strategic control of responses in affective priming

This experiment investigated the role of conflict in the response and evaluative categorization systems in the affective congruency effect using event-related brain potentials (ERPs). Participants completed a primed evaluative decision task in which the proportion of congruent to incongruent trials was manipulated. The size of the affective congruency effect increased along with the proportion of congruent trials. ERP data identified the locus of this effect in the response system: the lateralized readiness potential (LRP) showed that preferential response activation occurred in motor cortex following prime onset, and the fronto-central N2 (conflict monitoring) component indicated that conflict occurred when the response activated by the prime differed from the target response, irrespective of the affective congruency of the prime and target. The extent of this conflict covaried with strategic processing of primes, as participants directed less attention to primes that were likely to elicit conflict. These data support a response conflict account of affective congruency effects in the evaluative decision task and indicate that strategic control of attention is important in determining the extent to which conflict occurs.     

Assessing the effects of audiovisual semantic congruency on the perception of a bistable figure

Bistable figures provide a fascinating window through which to explore human visual awareness. Here we demonstrate for the first time that the semantic context provided by a background auditory soundtrack (the voice of a young or old female) can modulate an observer's predominant percept while watching the bistable "my wife or my mother-in-law" figure (Experiment 1). The possibility of a response-bias account-that participants simply reported the percept that happened to be congruent with the soundtrack that they were listening to-was excluded in Experiment 2. We further demonstrate that this crossmodal semantic effect was additive with the manipulation of participants' visual fixation (Experiment 3), while it interacted with participants' voluntary attention (Experiment 4). These results indicate that audiovisual semantic congruency constrains the visual processing that gives rise to the conscious perception of bistable visual figures. Crossmodal semantic context therefore provides an important mechanism contributing to the emergence of visual awareness.     

Flexible adjustments of visual selectivity in a Flanker task

Congruency effects observed in stimulus-response compatibility paradigms are affected by proportion congruency (PC), that is, the ratio of congruent trials in a block-wise context. The PC effect may reflect the operation of visual selectivity. We used a flanker task to investigate the nature of the relationship between the congruency effect and PC in a given block, as well as the preservation of visual selectivity. In Experiment 1, we observed a linear relationship between the congruency effect and PC across five PC groups in a training session; in post training (with PC constant), the congruency effect was equivalent across the five groups. In Experiment 2, congruency effects varied with PC in phases within a block. These suggest that visual selectivity, acquired in a training session, is not sustained in post training where it rapidly adjusts to a new PC context. Characteristics of visual selectivity derived from these findings are discussed.     

On the inability to ignore touch when responding to vision in the crossmodal congruency task

We investigated the extent to which people can selectively ignore distracting vibrotactile information when performing a visual task. In Experiment 1, participants made speeded elevation discrimination responses (up vs. down) to a series of visual targets presented from one of two eccentricities on either side of central fixation, while simultaneously trying to ignore task-irrelevant vibrotactile distractors presented independently to the finger (up) vs. thumb (down) of either hand. Participants responded significantly more slowly, and somewhat less accurately, when the elevation of the vibrotactile distractor was incongruent with that of the visual target than when they were presented from the same (i.e., congruent) elevation. This crossmodal congruency effect was significantly larger when the visual and tactile stimuli appeared on the same side of space than when they appeared on different sides, although the relative eccentricity of the two stimuli within the hemifield (i.e., same vs. different) had little effect on performance. In Experiment 2, participants who crossed their hands over the midline showed a very different pattern of crossmodal congruency effects to participants who adopted an uncrossed hands posture. Our results suggest that both the relative external location and the initial hemispheric projection of the target and distractor stimuli contribute jointly to determining the magnitude of the crossmodal congruency effect when participants have to respond to vision and ignore touch.