重复启动对时序知觉的影响

在时序判断任务中,重复启动导致被试把启动的靶刺激知觉为先出现的。知觉加工增强观和决策反应偏向观都试图解释其机制,但仍存在争议。本研究采用图形材料,通过三个实验系统考察了重复启动对时序知觉的影响。实验结果显示,启动和指导语都具有显著效应。这说明,重复启动对时序知觉的影响涉及知觉加工和决策水平两个方面。实验还首次发现,在启动的靶刺激先出现时发生了重复启动效应的反转。最后,研究提出了双加工表征匹配调节假说,用以综合解释目前的研究结果     

空间-时间关联的中介共同表征结构:来自反转STEARC效应的证据

通过3个双任务实验(诱导任务和特征任务)探讨空间-时间联合编码(STEARC)效应的加工机制。实验1采用时间信息作为诱导任务材料,实验2采用空间信息作为诱导任务材料,在特征任务中都发现映射不一致组被试(看到过去/左侧刺激时按右键反应,看到未来/右侧刺激时按左键反应)出现反转STEARC效应,映射一致组被试表现出常规的STEARC效应,表明从时间信息加工到空间反应过程符合中介共同表征结构。实验3分离两种任务的反应方式(手动和眼动),发现不一致映射规则下,被试仍然表现出常规的STEARC效应,表明这种中介共同表征结构存在特定联结效应,即在不同反应器中出现时间和空间相互独立的表征结构。总体而言,研究支持空间-时间关联符合中介共同表征结构,并且这种关联中存在反应器特定联结效应。     

无意识冲突的发生机制：基于Stroop范式的探讨

无意识信息对人们的行为有着十分重要的影响,它不仅能触发相对低级的认知功能而且也能触发冲突控制等相对高级的认知功能。尽管已有研究从行为和认知神经研究两个方面强有力地证实了无意识冲突的存在,但对无意识冲突是源自中枢加工产生的语义冲突还是晚期动作选择中产生的反应冲突存在激烈的争议。本研究采用分离语义冲突和反应冲突的实验逻辑在Stroop掩蔽启动任务中探讨了无意识冲突的机制。结果发现,无意识Stroop效应中既包含语义冲突又包含反应冲突。这说明无意识冲突可能由语义冲突和反应冲突共同构成。实验结果也进一步支持了无意识刺激可以加工到语义水平的观点。     

冲突观察能诱发冲突适应

重复启动效应和一致试次所占的比例都会影响冲突适应效应。采用词-色Stroop任务, 本研究在控制了重复启动效应和一致试次的比例之后, 通过三个实验共同探讨反应执行和冲突观察对冲突适应效应的影响。实验一发现当前试次的Stroop干扰效应, 但没有得到冲突适应效应; 在实验二中, 先前试次为四选一的选择反应时任务, 当前试次为词-色Stroop任务, 得到反转的冲突适应效应; 实验三和实验一程序相似, 但在先前试次上不执行反应, 得到了稳定的冲突适应效应。这些结果证明, 冲突观察能够诱发冲突适应机制, 提升当前的操作表现。     

知觉负载、注意定势与选择性注意

本研究采用Eriksen Flanker（侧抑制）范式,将当前任务区分为高、低知觉负载两种条件．并系统操纵边缘视野干扰项与中央靶子的不同加工层次关系,从而考察注意选择的知觉负载理论。实验一发现,高知觉负载情况下没有任何flanker冲突效应,而低知觉负载情况下既有知觉层次和反应层次的冲突效应,也有一致条件下的促进效应。实验二增加了一致条件试次的比例,从而操纵自上而下的注意定势,发现高、低知觉负载情况下都存在知觉冲突效应和一致条件下的促进效应。这些发现表明,对任务无关信息的加工既受到任务相关信息的知觉负载和剩余加工资源的分配的影响,也受到自上而下注意定势的影响;自下而上和自上而下过程相互作用,共同决定加工资源的分配和注意选择的认知阶段。     

时序知觉重复启动效应的作用机制

先前研究发现,时序判断任务在启动的靶刺激先出现时出现了重复启动效应的反转,这是以往的理论所不能单独解释的。通过两个实验对我们提出的双加工表征匹配调节假说加以实证检验,实验结果支持了该假说。因此,双加工表征匹配调节假说能较完整地综合解释时序知觉重复启动效应的作用机制     

认知和情绪词Flanker任务的冲突效应和冲突适应效应分析

采用词汇flanker任务分析认知和情绪冲突及其冲突适应效应。结果发现,在认知和情绪flanker任务中,相对于目标词与干扰词一致的情况,被试在目标词和干扰词不一致的情况下反应更慢,正确率更低。这表明认知词和情绪词flanker任务都能诱发冲突效应。本研究还发现认知冲突适应效应的存在,但没有发现情绪冲突适应效应,该结果可能与刺激材料的复杂性和范式选取有关。此外,研究还发现,相对于目标刺激是金属的认知词和积极的情绪词,被试对目标刺激是水果的认知词和消极的情绪词反应更快。特别是在目标词与干扰词不一致的情况下,被试对水果词和消极词判断的正确率要显著高于对金属词和积极词的判断。未来的研究需要在刺激和范式的修正上进一步探索,并加强情绪冲突与认知冲突适应效应的关系及其影响因素、神经机制的研究。     

知觉负荷对面孔多重社会范畴加工的影响

为了考察知觉负荷理论对于面孔多重社会范畴加工机制解释的可能性, 我们采用两个反应时实验探讨了姓名判断是否会在不同的知觉负荷条件下受到面孔性别与种族信息的影响。实验1通过侧抑制范式考察姓名判断中面孔种族引发的干扰效应是否会受到知觉负荷水平的调节。结果发现, 姓名判断的反应时间会随着负荷水平的提高显著延长, 即面孔种族引发的干扰效应不会随着负荷水平的提高而消失。实验2继续通过侧抑制范式考察了姓名判断中面孔性别引发的干扰效应是否会在不同知觉负荷水平下出现差异。结果发现, 在低负荷水平下, 个体在不一致条件下的反应时长于一致条件下的反应时, 并且被试会倾向于将中性名字的性别判断为与面孔的性别一致。在高负荷水平下, 个体的反应时在一致和不一致条件下没有显著差异, 并且被试对中性名字的性别判断属于随机猜测水平。上述结果表明, 种族加工具有自下而上的强制性加工的特点; 性别加工是受到注意资源调节的自上而下加工, 具有一定的灵活性。     

情境特异比例一致性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。     

高频靶词情绪启动的反转效应

实验采用词-词情绪启动范式,在SOA 5个水平上以高频情绪词为靶词,考察情绪启动的反转效应。结果在SOA各个水平上均发现反转效应,即被试对与启动刺激效价一致的靶刺激的反应较慢,而对与启动刺激效价不一致的靶刺激的反应较快。实验结果支持情绪转换模型和快速-准确策略理论。     

Gender differences on the semantic flanker task using transposed-letter target words

Previous research has demonstrated that men and women are differentially influenced by irrelevant distractors. Other lines of evidence have suggested that increasing the perceptual load of a task reduces distractor interference for participants generally. The present study examined these effects using a semantic version of the flanker task; participants made speeded responses to category target words that were flanked by irrelevant distractors. The response mapping between the target and flanker words was either congruent (mapped to the same motor response) or incongruent (target word mapped to a different motor response to that of the flankers). Target words were presented either normally (e.g., table: low perceptual load) or with the beginning letters transposed (e.g., atble: high perceptual load). The results revealed that women showed a larger congruency effect than men but this was not due to greater interference on incongruent trials. While men and women made faster responses to normal than to transposed target words, this was similar in magnitude. The magnitude of the flanker effect for normal and transposed target words was significantly correlated in men but not in women. These findings are consistent with the view that women may process target words to a deeper level than men and therefore may engage in more conflict monitoring then men.     

Flanker compatibility effects in patients with Parkinson's disease: impact of target onset delay and trial-by-trial stimulus variation

Parkinson’s disease (PD) patients and healthy controls were administered a flanker task that consisted of the presentation of colored targets and distractors. Participants were required to attend to the center target and identify its color. The stimulus displays were either congruent (i.e., the target and flankers were the same color) or incongruent. The time between the onset of the flanker and the target color (the target onset delay) was either short or long. Results indicated that PD patients and controls did not differ in the magnitude of the flanker effect within individual trials in that both groups demonstrated a typical flanker effect at the short target onset delay and neither group demonstrated a flanker effect at the longer delay. However, when performance was examined on a trial-by-trial basis, PD patients demonstrated a slowing of reaction time relative to controls when having to make the same response across consecutive trials at longer inter-trial intervals when the flankers were incongruent across consecutive trials and the display on the second of two trials was incongruent. These results indicate that PD patients are impaired in inhibiting the distractors over an extended delay and that this deficit may impact motor responding in these patients, suggesting that the basal ganglia contribute to the interface of attention and action.     

Gender differences on the semantic flanker task using transposed-letter target words

Previous research has demonstrated that men and women are differentially influenced by irrelevant distractors. Other lines of evidence have suggested that increasing the perceptual load of a task reduces distractor interference for participants generally. The present study examined these effects using a semantic version of the flanker task; participants made speeded responses to category target words that were flanked by irrelevant distractors. The response mapping between the target and flanker words was either congruent (mapped to the same motor response) or incongruent (target word mapped to a different motor response to that of the flankers). Target words were presented either normally (e.g., table: low perceptual load) or with the beginning letters transposed (e.g., atble: high perceptual load). The results revealed that women showed a larger congruency effect than men but this was not due to greater interference on incongruent trials. While men and women made faster responses to normal than to transposed target words, this was similar in magnitude. The magnitude of the flanker effect for normal and transposed target words was significantly correlated in men but not in women. These findings are consistent with the view that women may process target words to a deeper level than men and therefore may engage in more conflict monitoring then men.     

The Eriksen flanker effect revisited.

Four studies are reported on the potential role of perceptual interference in a standard Eriksen flanker task. In the first study, incongruent flanker letters showed the usual effect on choice reaction time (CRT) to the target letter but had no effect on the visual fixation time (VFT) needed to distinguish target and flankers. In the second experiment, the effect of incongruent flankers was studied in the context of a same-different response in regard to the target letter and a subsequently presented single letter. The effect of incongruent flankers vanished at an interstimulus interval of 200 ms. In Experiment 3, the same-different task was used in the paradigm of the functional visual field with a target-flankers combination as stimulus on the left (SL) and a single letter as stimulus on the right side (SR) of the visual field. Flankers did neither affect VFT nor the same-different CRT suggesting that target selection may proceed during the saccade from SL to SR. In Experiment 4 effects were studied of flanker-to-target and target-to-single-letter similarity. Flanker-to-target similarity did neither affect VFT nor same-different CRT but target-to-single-letter similarity prolonged same-different CRT. Together, the results suggest parallel perceptual processing of target and flankers, followed by competition of responses to the target and to the incongruent flankers. In line with earlier research, processes of response selection and response competition appear not to be tied to VFT but to proceed in parallel with the saccade from SL to SR.     

Flanker effects on motor output and the late-level response activation hypothesis.

When participants must respond to a relevant central target and ignore irrelevant flanking stimuli, the flankers produce a flanker compatibility effect on behavioural measures. Current accounts of the flanker compatibility effect assume that both target and flanker stimuli affect response activation. This idea is supported by electrophysiological studies, which show that irrelevant flanker stimuli can affect the motor system. The present experiments examined the characteristics of flanker effects on the motor system by analysing the details of the motor output with response force measures. A total of 60 participants responded in the flanker task to arrows (Experiment 1) or letters (Experiment 2). Reaction time as well as response force increased on incompatible trials. Analyses of the distribution of incorrect activation revealed that both response times and correct motor output increased with the amount of incorrect activity. However, the flanker compatibility effect was only marginally modulated by incorrect activity. Results suggest that the largest part of the flanker compatibility effect cannot be attributed to response activation and competition at late levels of the response system.     

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.     

Testing the attention shift hypothesis as an account for the flanker sequence-based congruency modulation in spatial flanker tasks

Smaller Simon effects when stimulus locations are repeated on successive trials rather than alternated have been explained by the attention shift hypothesis, suggesting that shifts of attention result in interfering response codes. We investigated whether the attention shift hypothesis can also explain smaller flanker effects for repeated flankers than for alternated flankers, which occur only with directional information. In 3 peripheral letter identification tasks, target locations were cued by partial or complete flanker stimuli. Experiments 1 and 2 showed that directional flankers elicit shifts of attention. However, Experiment 3 revealed that directional flankers induced inverted cuing effects when reacting to the central target arrow was additionally required. These results are difficult to reconcile with the attention shift hypothesis as an explanation for the congruency reduction with repetitions of directional flankers.     

Flanker and negative flanker effects in letter identification

In a speeded choice reaction time task, responses to centrally presented letter targets can be altered by the identity of surrounding task-irrelevant letters (flankers). In the standard flanker effect, flankers associated with the same response as the target lead to faster and more accurate responses, whereas flankers associated with a different response lead to slower and more error-prone responses. B. A. Eriksen and C. W. Eriksen (1974, pp. 143-149) have argued that these flanker effects occur through response competition. We present data from a novel version of the Eriksen task, in which some targets and flankers consist of letter forms that are morphed versions of target letters. In this paradigm, flankers induce classic flanker effects on well-formed targets. But flankers induce an opposite effect, termed a negative flanker effect on morphed letter targets. For example, targets that are morphs between the letters "A" and "H" are more likely to be identified as an "A" when flanked by an "H." The interpretation advanced here is that there are two distinct kinds of flanker effects contrast enhancement in perceptual processes and response competition in response selection processes.     

Orientation asymmetry in the flanker task

Experiments 1 and 2 of this study show that when the target is either a vertical or a horizontal line, diagonal-line flankers tilted 45° either to the right or to the left have the same effect as do incongruent flankers. When the target is a diagonal line tilted either to the right or to the left, vertical- or horizontal-line flankers do not have the same effect as do incongruent flankers. Experiment 3 demonstrates that this asymmetry is not caused by the temporal-dynamic aspects of the processing. Together, these experiments suggest that there is an asymmetrical relation between diagonal lines and either vertical or horizontal lines otttside of the central focus of attention. Experiment 4 shows that despite this asymmetry in the flanker task, visual search for a vertical- or a horizontal-line target among diagonal-line distractors is not affected by the number of distractors. Possible explanations of this phenomenon are discussed.     

Now you see it, now you don't: controlling for contingencies and stimulus repetitions eliminates the Gratton effect

The Gratton (or sequential congruency) effect is the finding that conflict effects (e.g., Stroop and Eriksen flanker effects) are larger following congruent trials relative to incongruent trials. The standard account given for this is that a cognitive control mechanism detects conflict when it occurs and adapts to this conflict on the following trial. Others, however, have questioned the conflict adaptation account and suggested that sequential biases might account for the Gratton effect. In two experiments, contingency biases were removed from the task and stimulus repetitions were deleted to control for stimulus bindings. This eliminated the Gratton effect in the response times in both experiments, supporting a non-conflict explanation of the Gratton effect. A Gratton effect did persist in the errors of Experiment 1; however, this effect was not produced by the type of errors (word reading errors) that a conflict adaptation account should predict. Instead, tentative support was found for a congruency switch cost hypothesis. In all, the conflict adaptation account failed to account for any of the reported data. Implications for future work on cognitive control are discussed.