Directed forgetting of autobiographical events

Two diary experiments demonstrated directed forgetting (DF) of autobiographical events, previously observed only for less complex memory items. Using a 2-week diary paradigm, we compared recall between a group of participants who were directed to forget Week 1 memories (forget group) and a group who did not receive a forget instruction (remember group). In Experiment 1, the forget group remembered fewer items from Week 1 than did the remember group. The effect was observed for negative and positive valence events, as well as for high and low emotional intensity events. The effect was replicated in Experiment 2 despite a memorable holiday (Valentine's Day) that occurred during the manipulation week. Forget participants remembered fewer low emotional intensity items in Experiment 2. We conclude that intentional forgetting is a plausible explanation for the loss of some autobiographical memories.     

Recognition memory for elements of sentences

Although several theoretical positions and a variety of empirical tasks indicate the importance of verbs to sentences, nouns are generally recalled and recognized better in memorial tasks. Three main models can be identified to explain this discrepancy ("Fillenbaum's paradox"). To try to resolve this paradox, several experiments explored the efficiency of various sentence elements as cues in recognition memory. In Experiment I, concreteness of the stimuli did not interact with the type of distractor; however, verb phrase changes were harder to recognize than noun phrase changes when synonym distractors were used. This result was replicated in a forced-choice recognition paradigm (Experiment II) and with whole sentences where the derivational similarity of verbs and nouns was controlled (Experiment IV). The effect could not be attributed to characteristics of the English language (Experiment III) or to superior memory for form information in nouns (Experiment V). The total results are interpreted as suggesting that subjects process different parts of a sentence to different semantic levels, with verbs receiving more semantic representation and nouns more orthographic or phonological representation. The results are taken as support for a "semantic encoding model" of Fillenbaum's paradox.     

Spatial frequency filtering and the direct control of fixation durations during scene viewing

The present study employed a saccade-contingent change paradigm to investigate the effect of spatial frequency filtering on fixation durations during scene viewing. Subjects viewed grayscale scenes while encoding them for a later memory test. During randomly chosen saccades, the scene was replaced with an alternate version that remained throughout the critical fixation that followed. In Experiment 1, during the critical fixation, the scene could be changed to high-pass and low-pass spatial frequency filtered versions. Under both conditions, fixation durations increased, and the low-pass condition produced a greater effect than the high-pass condition. In subsequent experiments, we manipulated the familiarity of scene information during the critical fixation by flipping the filtered scenes upside down or horizontally. Under these conditions, we observed lengthening of fixation durations but no difference between the high-pass and low-pass conditions, suggesting that the filtering effect is related to the mismatch between information extracted within the critical fixation and the ongoing scene representation in memory. We also conducted control experiments that tested the effect of changes to scene orientation (Experiment 2a) and the addition of color to a grayscale scene (Experiment 2b). Fixation distribution analysis suggested two effects on the distribution fixation durations: a fast-acting effect that was sensitive to all transsaccadic changes tested and a later effect in the tail of the distribution that was likely tied to the processing of scene information. These findings are discussed in the context of theories of oculomotor control during scene viewing.     

Deduction without awareness

We investigated whether two basic forms of deductive inference, Modus Ponens and Disjunctive Syllogism, occur automatically and without awareness. In Experiment 1, we used a priming paradigm with a set of conditional and disjunctive problems. For each trial, two premises were shown. The second premise was presented at a rate designed to be undetectable. After each problem, participants had to evaluate whether a newly-presented target number was odd or even. The target number matched or did not match a conclusion endorsed by the two previous premises. We found that when the target matched the conclusion of a Modus Ponens inference, the evaluation of the target number was reliably faster than baseline even when participants reported that they were not aware of the second premise. This priming effect did not occur for any other valid or invalid inference that we tested, including the Disjunctive Syllogism. In Experiment 2, we used a forced-choice paradigm in which we found that some participants were able to access some information on the second premise when their attention was explicitly directed to it. In Experiment 3, we showed that the priming effect for Modus Ponens was present also in subjects who could not access any information about P(2). In Experiment 4 we explored whether spatial relations (e.g., "a before b") or sentences with quantifiers (e.g., "all a with b") could generate a priming effect similar to the one observed for Modus Ponens. A priming effect could be found for Modus Ponens only, but not for the other relations tested. These findings show that the Modus Ponens inference, in contrast to other deductive inferences, can be carried out automatically and unconsciously. Furthermore, our findings suggest that critical deductive inference schemata can be included in the range of high-level cognitive activities that are carried out unconsciously.     

Are covert verbal responses mediating false implicit memory?

In the DRM paradigm, illusory memories of a nonpresented word can be induced by the presentation of strong associates to this word. In two experiments, we explored previous findings of false implicit memory of the nonpresented words (McDermott, 1997; McKone & Murphy, 2000). Experiment 1 extended the finding of false priming to the anagram task. Furthermore, participants attributed this "false" influence on performance to the difficulty of the anagrams and judged them as easier to solve for other students. In Experiment 2, articulatory suppression during the study of the associates resulted in nonsignificant levels of false priming, whereas the normal priming effect was in the same range as that observed in Experiment 1. The study replicates and extends findings of false implicit memory to the anagram task and suggests that future studies should examine the role of covert verbal responses in producing false implicit memory.     

Event-related potential evidence for multiple causes of the revelation effect

Asking people to discover the identity of a recognition test probe immediately before making a recognition judgment increases the probability of an old judgment. To inform theories of this "revelation effect," event-related potentials (ERPs) were recorded for revealed and intact test items across two experiments. In Experiment 1, we used a revelation effect paradigm where half of the test probes were presented as anagrams (i.e., a related task) and the other items were presented intact. The pattern of ERP results from this experiment suggested that revealing an item decreases initial familiarity levels and caused the revealed items to elicit similar levels of activity. In Experiment 2, half of the probes were preceded by an addition task (i.e., an unrelated task). The pattern of ERP effects in this study were distinct from those observed in Experiment 1. More specifically, revealed item ERPs were more negative than intact ERPs at frontal electrodes and more positive at parietal electrodes early in the interval. Later in the epoch, revealed item ERPs were more negative than intact items. These data suggest that related tasks decrease familiarity and alter the signal-to-noise ratio of old and new items, whereas unrelated tasks affect processing in a different way (perhaps by changing decision processes) that also results in the revelation effect. The implications for current theories of the revelation effect are discussed.     

汉语背景下横纵轴上的心理时间线

采用反应区分范式, 以表示过去和未来的时间词为刺激, 对汉语背景下横、纵两轴上的时间表征情况进行了探讨。结果发现, (1)横、纵轴方向上都出现了STEARC效应; (2)右对角线方向上, 出现了服从横轴的减弱的STEARC效应, 且STEARC效应值呈正态分布。以上结果表明, 汉语背景下既存在从左向右的心理时间线, 也存在从上到下的心理时间线, 两种时间表征同时存在, 且横轴表征倾向于占优势。     

Recognizing disguised faces

Across three experiments, we evaluated the effects of “disguises” on observers’ face identification performance using naturalistic images in which individuals posed with a variety of wigs and eyeglasses. Experiment 1 tested recognition memory performance with and without disguises and showed that any changes in these facial attributes hindered performance, replicating previous findings. More interestingly, Experiment 1 revealed that a change in hairstyle or the removal of eyeglasses had more impact on performance than did the addition of eyeglasses. In Experiment 2, disguised and undisguised faces were presented upright or inverted to examine whether the performance decrements seen in Experiment 1 were attributable to disruption of processing strategies for faces. Despite showing an overall effect of disguise on performance, there was no interaction between inversion and disguise. This suggests that disguises are not directly affecting processing strategies, but instead disguises are likely encoded as part of the overall representation. Similarly, in Experiment 3, the composite face paradigm was used to examine whether the impact of disguises is attributable to disruption of holistic processing for faces. Again, we found an overall effect of disguise on performance, but here we also observed that the presence of disguises interacted with participants’ tendency to form holistic face representations.     

The effects of a flavour - toxicosis pairing upon long-delay, flavour aversion learning

Mackintosh (1973) has suggested that rats readily associate flavours with illnesses in cue-to-consequence studies because they have already learned that changes in internal states are unrelated to changes in external stimuli. An implication of this suggestion is that learned predispositions may also subserve the ability of rats to form long-delay, flavour-illness associations. Six experiments tested this idea by examining the strengths of aversions in a delayed flavour-toxicosis paradigm after exposure to a paired or unpaired relation between another flavour and toxicosis. Exposure to a paired relation enhanced the strengths of subsequently established flavour aversions (Experiment I). The enhanced aversions were associative in origin (Experiment II), observed with delays of 3 h and 1·5 h in, respectively, a forward (Experiment III) and backward (Experiment IV) delayed conditioning paradigm and with a 10-day interval between the flavour-toxin pairing and the delayed paradigm (Experiment V). The enhanced aversions, however, were removed by the extinction of the original flavour aversion prior to the delayed flavour-toxin pairing (Experiment VI). The results supported the idea that the ability of the rat to form long-delay, flavour-illness associations reflects an associative history involving flavours and internal changes and were discussed in terms of Mackintosh's (1975) theory of the mechanism underlying stimulus selection. The effects of a flavour-toxicosis pairing upon long-delay, flavour aversion learning.     

Agrammatic production of subject-verb agreement: the effect of conceptual number.

Three experiments tested the hypothesis that the deficit underlying agrammatic sentence production difficulties can be characterized as a limitation of computational resources and that these resources are not restricted to syntactic processing. This hypothesis was tested by eliciting subject-verb agreement errors in a sentence fragment completion paradigm. Sentence fragments were complex noun phrases, containing a subject (head) noun and a modifying prepositional phrase, containing a "local" noun. We varied the number of "tokens" a singular head noun referred to. Therefore, in one condition, grammatical and conceptual number of the head noun mismatched, whereas these numbers were the same in another condition. In Experiments 1 and 2, we observed an effect of this variable (i.e., more agreement errors when conceptual number was plural and grammatical number singular) in normal controls. Broca's aphasics, on the other hand, showed no effect. Experiment 3 consisted of a sentence/picture matching test. This test showed that the lack of effect with Broca's aphasics cannot be attributed to a comprehension deficit. We argue that these results are incompatible with the notion of a limitation in resources specific for syntactic processing. Instead, we interpret this as the result of a trade-off: Broca's aphasics lack computational resources to take into account both grammatical and conceptual information in morphosyntactic processing and rely on grammatical information only.     

Recognition memory performance as a function of reported subjective awareness

Three experiments introduced a recognition memory paradigm designed to investigate reported subjective awareness during retrieval. At study, in Experiments 1A and 2, words were either generated or read (generation), while modality of presentation (auditory versus visual) was manipulated in Experiment 1B. Word pairs (old/new or new/new) were presented during test trials, and participants indicated if they contained an old word by responding "remember", "know" or "new" in Experiments 1A and 1B, and by responding "strong no", "weak no", "weak yes", or "strong yes" in Experiment 2. Participants were then required to decide which of the 2 words was old. We demonstrated that the proportion measures used in the Remember Know paradigm substantially underestimated the influence of generation on familiarity resulting in an artificial dissociation between indices of knowing (familiarity) and remembering (recollection). We also found a qualitatively different pattern of forced-choice recognition performance as a function of claimed awareness.     

Valence resolution of ambiguous facial expressions using an emotional oddball task

Previous research suggests that neural and behavioral responses to surprised faces are modulated by explicit contexts (e.g., "He just found $500"). Here, we examined the effect of implicit contexts (i.e., valence of other frequently presented faces) on both valence ratings and ability to detect surprised faces (i.e., the infrequent target). In Experiment 1, we demonstrate that participants interpret surprised faces more positively when they are presented within a context of happy faces, as compared to a context of angry faces. In Experiments 2 and 3, we used the oddball paradigm to evaluate the effects of clearly valenced facial expressions (i.e., happy and angry) on default valence interpretations of surprised faces. We offer evidence that the default interpretation of surprise is negative, as participants were faster to detect surprised faces when presented within a happy context (Exp. 2). Finally, we kept the valence of the contexts constant (i.e., surprised faces) and showed that participants were faster to detect happy than angry faces (Exp. 3). Together, these experiments demonstrate the utility of the oddball paradigm to explore the default valence interpretation of presented facial expressions, particularly the ambiguously valenced facial expression of surprise.     

Hypermnesia: Age-related differences between young and older adults

Hypermnesia is a net improvement in memory performance that occurs across tests in a multitest paradigm with only one study session. Our goal was to identify possible age-related differences in hypermnesic recall. We observed hypermnesia for young adults using verbal (Experiment 1) as well as pictorial (Experiment 2) material, but no hypermnesia for older adults in either experiment. We found no age-related difference in reminiscence (Experiments 1 and 2), though there was a substantial difference in intertest forgetting (Experiments 1 and 2). Older, relative to young, adults produced more forgetting, most of which occurred between Tests 1 and 2 (Experiments 1 and 2). Furthermore, older, relative to young, adults produced more intrusions. We failed to identify a relationship between intrusions and intertest forgetting. We suggest that the age-related difference in intertest forgetting may be due to less efficient reinstatement of cues at test by older adults. The present findings reveal that intertest forgetting plays a critical role in hypermnesic recall, particularly for older adults.     

Phonological effects in handwriting production: evidence from the implicit priming paradigm

In the present article, we report 3 experiments using the odd-man-out variant of the implicit priming paradigm, aimed at determining the role played by phonological information during the handwriting process. Participants were asked to write a small set of words learned in response to prompts. Within each block, response words could share initial segments (constant homogeneous) or not (heterogeneous). Also, 2 variable homogeneous blocks were created by including a response word that did not share orthographic onset with the other response (odd-man-out). This odd-man-out could be phonologically related to the targets or not. Experiment 1 showed a preparation effect in the constant homogeneous condition, which disappeared (spoil effect) in the variable condition not phonologically related. However, no spoil effect was found when the odd-man-out shared the phonological initial segment with the targets. In Experiment 2, we obtained a spoil effect in the variable phonologically related condition, but it was significantly smaller than in the variable not phonologically related condition. The effects observed in Experiment 2 vanished in Experiment 3 under articulatory suppression, suggesting that they originated at a sublexical level. These findings suggest that phonological sublexical information is used during handwriting and provide evidence that the implicit priming paradigm (and the odd-man-out version of this) is a suitable tool for handwriting production research.     

Accuracy of familiarity decisions to famous faces perceived without awareness depends on attitude to the target person and on response latency

Stone and Valentine (2004) presented masked 17 ms faces in simultaneous pairs of one famous and one unfamiliar face. Accuracy in selecting the famous face was higher when the famous person was regarded as "good" or liked than when regarded as "evil" or disliked. Experiment 1 attempted to replicate this phenomenon, but produced a different pattern of results. Experiment 2 investigated alternative explanations and found evidence supporting only the effect of response latency: responses made soon after stimulus onset were more accurate to liked than to disliked faces, whereas responses made after a longer delay were equally accurate to disliked faces. It appears that the effect of negative valence was corrected within the space of a few hundred milliseconds. Experiment 3, using an affective priming paradigm, supported the concept that an early-arising effect of valence is corrected if it is misleading to the directed task.     

The return of object-based attention: selection of multiple-region objects

Objects can control the focus of attention, allowing features on the same object to be selected more easily than features on different objects. In the present experiments, we investigated the perceptual processes that contribute to such object-based attentional effects. Previous research has demonstrated that object-based effects occur for single-region objects but not for multiple-region objects under some conditions (Experiment 1, Watson & Kramer, 1999). Such results are surprising, because most objects in natural scenes are composed of multiple regions. Previous findings could therefore limit the usefulness of an object-based selection mechanism. We explored the generality of these single-region selection results by manipulating the extent to which different (i.e., multiple) regions of a single object perceptually grouped together. Object-based attentional effects were attenuated when multiple regions did not group into a single perceptual object (Experiment 1). However, when multiple regions grouped together based on (1) edge continuation (Experiments 2 and 3) or (2) part and occlusion cues (Experiment 4), we observed object-based effects. Our results suggest that object-based attention is a robust process that can select multiple-region objects, provided the regions of such objects cohere on the basis of perceptual grouping cues.     

情绪的动机维度对趋避行为的影响

基于Gable和Harmone-Jones提出的情绪的动机维度模型,本研究采用改进的模拟“小人”任务实验范式考察了情绪的动机维度如何影响趋避行为。研究结果表明：（1）改进的模拟“小人”任务范式能较好地考察情绪对趋避行为的影响;（2）对情绪图片的有意识和无意识加工均出现了“趋利避害的相容效应”,较好地解决了动机定向理论和事件编码理论的纷争;（3）和低动机强度积极情绪相比,高动机强度积极情绪对趋近行为的易化程度更高;和低动机强度消极情绪相比,高动机强度消极情绪对回避行为的易化程度更髙。     

Automatic change detection in vision: Adaptation,memory mismatch,or both? II: Oddball and adaptation effects on event-related potentials

In this study we compared the event-related potentials (ERPs) obtained in two different paradigms: a passive visual oddball paradigm and an adaptation paradigm. The aim of the study was to investigate the relation between the effects of activity decrease following an adaptor (stimulus-specific adaptation) and the effects of an infrequent stimulus within sequences of frequent ones. In Experiment 1, participants were presented with different line textures. The frequent (standard) and rare (deviant) texture elements differed in their orientation. In Experiment 2, windmill pattern stimuli were presented in which the number of vanes differentiated the deviant and standard stimuli. In Experiment 1 the ERP differences elicited between the oddball deviant and the standard were similar to the differences between the ERPs to the nonadapted and adapted stimuli in the adaptation paradigm. In both paradigms the differences appeared as a posterior negativity with the latency of 120–140 ms. This finding demonstrates that the representation of a sequential rule (successive presentation of the standard) and the violation of this rule are not necessary for deviancy effects to emerge. In Experiment 2 (windmill pattern), in the oddball paradigm the difference potentials appeared as a long-lasting negativity. In the adaptation condition, the later part of this negativity (after 200 ms) was absent. We identified the later part of the oddball difference potential as the genuine visual mismatch negativity—that is, an ERP correlate of sequence violations. The latencies of the difference potentials (deviant minus standard) and the endogenous components (P1 and N1) diverged; therefore, the adaptation of these particular ERP components cannot explain the deviancy effect. Accordingly, the sources contributing to the standard-versus-deviant modulations differed from those related to visual adaptation; that is, they generated distinct ERP components.     

Asymmetry of automatic change detection shown by the visual mismatch negativity: An additional feature is identified faster than missing features

In two experiments, we demonstrated that an asymmetric effect of the brain electric activity that is elicited by nonattended visual stimuli is similar to the one found in responses observed in the performance of visual search tasks. The automatic detection of violated sequential regularities was investigated by measuring the visual mismatch negativity (vMMN) component of event-related brain potentials (ERPs). In Experiment 1, within a sequence of stimulus displays with O characters, infrequently presented Q characters elicited an earlier vMMN than did infrequent O characters within a sequence of Q characters. In Experiment 2, similar asymmetric results emerged if only 16 % of the characters were different within an infrequent display. In both experiments, these stimuli were irrelevant; during the stimulus sequences, participants performed a demanding videogame. We suggest that the underlying match/mismatch and decision processes are similar in the vMMN and in the attention-related visual search paradigm, at least in the case of the stimuli in the present experiments.