Memory and memory confidence in obsessive-compulsive disorder

Pathological doubt, often found in individuals with obsessive-compulsive disorder (OCD), has been theoretically linked to memory deficits, but empirical evidence for such deficits has been mixed. In contrast, many studies suggest that individuals with OCD have low confidence in their memories. The present study aimed to build upon previous research by measuring memory accuracy and confidence in OCD using ecologically valid, idiographically-selected stimuli. Individuals with OCD (OCs), anxious controls (ACs), and nonanxious controls (NACs) were exposed to a set of objects that the OCs had identified as safe, unsafe, or neutral. Participants were then asked to recall as many objects as possible and to rate their confidence in each memory. This process was repeated 6 times, using the same stimuli for each trial. Contrary to hypothesis, no group differences emerged in memory accuracy. However, OCs' memory confidence for unsafe objects showed a progressive decline over repeated trials. This pattern was not observed among NACs or ACs. Furthermore, OCs with primary checking reported lower confidence in long-term memory than did OCs without primary checking. These results suggest that when OCs are repeatedly exposed to threat-related stimuli (such as repeated checking), their level of confidence in remembering these stimuli paradoxically decreases.     

Threat processing in obsessive-compulsive disorder: evidence from a modified negative priming task

Individuals with obsessive-compulsive disorder (OCD) often experience intrusive thoughts. These intrusions may be due to biases in information processing mechanisms, including attention, memory, and learning. To examine this hypothesis, we presented a modified negative priming (NP) paradigm with idiographically selected words to 19 individuals with OCD (OCs) and 19 matched non-anxious control participants (NACs). The words included OCD-relevant threat, OCD-relevant positive, and neutral words. This paradigm typically elicits positive priming because participants may learn the contingency between the prime and probe that facilitates responding [Frings and Wentura (2006). Strategy effects counteract distractor inhibition: NP with constantly absent probe distractors. Journal of Experimental Psychology: Human Perception and Performance, 32, 854-864]. As predicted, NACs showed facilitation (i.e., positive priming) rather than NP for all word types, whereas OCs exhibited facilitation for only neutral words. For positive words, OCs exhibited no priming and for threat words they exhibited NP. These results suggest that for idiographic, OCD-relevant threat information, individuals with OCD show difficulty learning the contingency between the information in the prime and probe displays relative to the NACs.     

Cognitive control of obsessional thoughts

A defining characteristic of obsessive-compulsive disorder (OCD) is unsuccessful suppression of unwanted thoughts. Recent evidence of individual differences in ability to control intrusive thoughts may inform our understanding of failures of cognitive control associated with OCD symptomatology. The current study investigated characteristics of cognitive style that are potentially associated with OCD symptoms and may influence response to unwanted thoughts, including perceived ability to control thoughts and tendency to ruminate. Undergraduate students (N = 166) completed self-report measures of OCD symptoms, perceived thought control, and ruminative thinking. They were then presented with a distressing target thought and completed a standard thought suppression paradigm. Correlational results indicated that, controlling for anxiety and depression, OCD symptoms were positively associated with rumination and inversely associated with perceived thought control ability. In addition, OCD symptoms were associated with higher levels of distress and greater spontaneous efforts to suppress the target thought during a baseline period, while perceived thought control ability predicted frequency of target thoughts during suppression. Finally, results of the experimental manipulation confirmed that participants instructed to suppress experienced more intrusions during the recovery period. Clinical implications and future directions are discussed.     

Suppression of obsession-like thoughts in nonclinical individuals: impact on thought frequency, appraisal and mood state

Wegner's (1994, Psychological Review, 101, 34-52) research on the paradoxical effect of thought suppression has been incorporated into contemporary cognitive-behavioural models of obsessive-compulsive disorder. However, findings on the effects of thought suppression on thought frequency have been inconsistent and few studies have actually examined the suppression of thoughts that are obsessional in nature. In the present study 219 nonclinical participants were randomly assigned to suppress or not suppress a neutral, obsessional or positive thought during an initial monitoring interval. In a second thought monitoring interval, all participants received instructions not to suppress their target thought. No paradoxical effect of suppression on frequency was observed for any type of thought, although suppression of obsessional thoughts was associated with greater subsequent discomfort and a more negative mood state than suppression of positive or neutral target thoughts.     

Are "obsessive" beliefs specific to OCD?: a comparison across anxiety disorders

Cognitive models of obsessive-compulsive disorder (OCD) assign a central role to maladaptive beliefs about threat, uncertainty, importance and control of thoughts, responsibility, and perfection. Previous research has demonstrated that such beliefs relate to specific OCD symptoms in a theoretically meaningful way. The aim of the present study was to determine whether these beliefs are endorsed more strongly by OCD patients than by those with other anxiety disorders. Eighty-nine adult OCD patients, 72 anxious control (AC) patients, and 33 nonclinical control (NCC) participants completed a measure of obsessive beliefs as well as measures of depression and trait anxiety. Compared to NCCs and ACs, OCD patients more strongly endorsed beliefs related to threat estimation, tolerance of uncertainty, importance and control of thoughts, and perfectionism, but not inflated responsibility. Using revised, condensed subscales, OCD patients differed from ACs on beliefs about perfectionism and certainty and about importance and control of thoughts, but not on beliefs about threat estimation and inflated responsibility. When controlling for depression and trait anxiety, the OCD and AC group did not differ on most belief domains, except for a belief that it is possible and necessary to control one's thoughts. Results are discussed in light of evolving cognitive-behavioral theories that highlight appraisals of thought control and the use and effectiveness of varying thought control strategies.     

Thought suppression and its effects on thought frequency, appraisal and mood state in individuals with obsessive-compulsive disorder

Leading models of obsessive-compulsive disorder (OCD) implicate thought suppression as a key factor in the escalation and persistence of the disorder. This experiment examined the effects of suppression on the frequency of obsessional thoughts in 50 individuals with a primary diagnosis of OCD, and also investigated the effects of participants' appraisals regarding their failures in thought control on distress about intrusive thoughts and on mood. Participants' most upsetting obsessional thought was primed and they then monitored its occurrence over two 4-min intervals. In the first interval, half of the participants were instructed to suppress their obsessional thought and half were instructed not to suppress any thoughts. In the second interval, all participants were given the 'Do Not Suppress' instructions. Participants rated their suppression effort and discomfort over thought occurrences after each interval and recorded their appraisals of thought recurrences during the first interval. Mood state was then reassessed. No ironic effect of suppression on frequency was noted. However, negative appraisals of thought recurrences were associated with more discomfort over thought occurrences and more negative mood at Time 2. These findings suggest that interpretations regarding failures in thought control may be of central importance in understanding obsessional problems.     

非熟练潮-粤双言者的语义通达：来自听觉词加工的证据

采用听觉跨语言启动的语义判断范式, 考察非熟练潮-粤双言者的两种方言之间的语义通达方式。结果发现, 无论是以潮语词为启动词, 还是以粤语词为启动词, 当二者具有翻译关系时, 启动词均促进对目标词的识别, 但L1对L2的启动量比L2对L1的启动量大。当启动词与目标词具有语义联想关系时, 启动词亦能促进对目标词的识别, 但L1→L2与L2→L1的启动量差异不显著。整个研究表明, 非熟练潮-粤双言者的两种方言的词汇独立表征, 语义共享表征; 第二方言的词汇能够直接通达语义表征, 不需要以第一方言的词汇为中介, 但双言的词汇表征与语义表征的联结强度仍然存在着不对称性。     

Effects of suppressing neutral and obsession-like thoughts in normal subjects: beyond frequency

Recent cognitive-behavioral theories on obsessive-compulsive disorder (OCD) show that deliberate attempts to suppress intrusive and undesirable thoughts lie at the genesis of clinical obsessions. In this paper the results of an experimental study on the suppression of neutral and obsession-like thoughts in normal subjects are presented. Eighty-seven university students performed in three experimental periods: (1) base-line monitoring, (2) experimental instruction, and (3) monitoring. For each of these periods, the frequency of the occurrence of a "white bear" thought or a personally relevant intrusive thought was registered. Half of the subjects received instructions to suppress the target-thought in period 2, and the other half were instructed to only monitor the target-thought in each of the experimental periods. Several measures were also obtained before and after the experiment: annoyance caused by the intrusion, suppression effort, subjective success, and evaluative appraisals of the target-thought. The results showed neither immediate nor delayed frequency increases of the target thought. However, evidence was found that deliberate thought suppression efforts, regardless of their content, had greater negative consequences than did non suppression. These results are discussed in relation to the recent cognitive proposals about OCD.     

The gravity of unwanted thoughts: Asymmetric priming effects in thought suppression

An unwanted thought appears to be cued easily by reminders in the environment but often the thought itself seems to cue nothing more than the desire to eliminate it from consciousness. This unusual asymmetry in the way unwanted thoughts are linked to other thoughts was the focus of the present research. Participants who were asked to suppress a thought or to concentrate on it completed a task assessing the influence of priming on reaction time (RT) for word/non-word judgments. Results revealed that suppression under cognitive load produced asymmetric priming: Priming with the associate of a suppressed word speeded RT for the suppressed word, but priming with a suppressed word did not speed RT for associated words. These findings suggest that thought suppression induces an unusual form of cognitive accessibility in which movement of activation toward the suppressed thought from associates is facilitated but movement of activation away from the suppressed thought to associates is undermined.     

Rapid naming is affected by association but not by syntax

Three experiments are reported that focused on the grammatical and associative relationship between a single-word context and a to-be-named target in the Serbo-Croatian language. Unlike in studies using the English language, word class need not be violated in order to obtain grammatical incongruency: all word pairs, therefore, can be semantically plausible. Experiment 1 contrasted naming with lexical decision using associative and grammatical priming, a replication of Seidenberg, Waters, Sanders, and Langer’s (1984) study. With associative priming, both lexical decision and naming were facilitated significantly, but with grammatical priming, only lexical decision was affected significantly. Heeding observations of West and Stanovich (1986), in Experiment 2 we used stimuli known to produce a robust grammatical congruency effect on lexical decision (130 msec) and a procedure designed to slow naming latencies. Again, no grammatical congruency effect for naming was obtained. Finally, because Experiment 1, which used a row of Xs as the neutral context, showed an associative priming effect on naming pseudowords, Experiment 3 used a neutral context that was linguistic. An associative priming effect was found for words but not for pseudowords. Results were discussed in terms of pre- and postlexical loci of contextual effects.     

Perceptual and response components in repetition priming of spoken words and pseudowords

Two experiments explored repetition priming effects for spoken words and pseudowords in order to investigate abstractionist and episodic accounts of spoken word recognition and repetition priming. In Experiment 1, lexical decisions were made on spoken words and pseudowords with half of the items presented twice (～12 intervening items). Half of all repetitions were spoken in a “different voice” from the first presentations. Experiment 2 used the same procedure but with stimuli embedded in noise to slow responses. Results showed greater priming for words than for pseudowords and no effect of voice change in both normal and effortful processing conditions. Additional analyses showed that for slower participants, priming is more equivalent for words and pseudowords, suggesting episodic stimulus–response associations that suppress familiarity-based mechanisms that ordinarily enhance word priming. By relating behavioural priming to the time-course of pseudoword identification we showed that under normal listening conditions (Experiment 1) priming reflects facilitation of both perceptual and decision components, whereas in effortful listening conditions (Experiment 2) priming effects primarily reflect enhanced decision/response generation processes. Both stimulus–response associations and enhanced processing of sensory input seem to be voice independent, providing novel evidence concerning the degree of perceptual abstraction in the recognition of spoken words and pseudowords.     

Long-term priming of neighbours biases the word recognition process: evidence from a lexical decision task.

The role of orthographically similar words (i.e., neighbours) in the word recognition process has been studied extensively using short-term priming paradigms (e.g., Colombo, 1986). Here we demonstrate that long-term effects of neighbour priming can also be obtained. Experiment 1 showed that prior study of a neighbour (e.g., TANGO) increased later lexical decision performance for similar words (e.g., MANGO), but decreased performance for similar pseudowords (e.g., LANGO). Experiment 2 replicated this bias effect and showed that the increase in lexical decision performance due to neighbour priming is selectively due to words from a relatively sparse neighbourhood. Explanations of the bias effect in terms of lexical activation and episodic memory retrieval are discussed.     

Organization of the Self-Concept and the Suppression of Self-Relevant Thoughts

The rebound effect associated with thought suppression has been found following attempts at suppressing both novel stimuli and stereotypical thoughts. However, research examining the suppression of self-relevant thoughts has been less successful in demonstrating the rebound effect. A potential factor that has not yet been fully explored in research on thought suppression is how different types of distracter thoughts may influence the ability to suppress unwanted thoughts. One type of distracter that people may use while attempting to suppress unwanted self-relevant thoughts is information related to other aspects of their lives. To the extent that these other aspects are more likely to be associated in memory with the unwanted thoughts, rebound should be more likely to occur. Thus, we expected and found that people lower in self-complexity (i.e., those with fewer self-aspects that are more interrelated with one another) revealed greater rebound following thought suppression that involved self-relevant distracting thoughts than did people greater in self-complexity. Implications of these findings for thought suppression, self-complexity, depression, and the experience of affect are discussed.     

Hunger-related intrusive thoughts reflect increased accessibility of food items

The elaborated intrusion model (Kavanagh, Andrade, & May, 2005) argues that a craving episode begins with a desire-related intrusive thought. This study tests the assumption that such intrusive thoughts, during hunger, reflect an increase in accessibility of food-related information in memory. Fifty-six undergraduates were randomly assigned to hungry or satiated conditions. Hunger was manipulated by asking the “hungry” group to abstain from eating breakfast and snacks prior to testing before lunch, while the “satiated” group was asked to eat normally and attend testing after lunch. Participants completed a lexical decision task containing food-related and neutral words, an intrusive thoughts questionnaire and a hunger questionnaire. Priming for food-related items relative to neutral on the lexical decision task was higher for hungry participants than satiated participants. Priming correlated strongly with frequency of food-related intrusive thoughts during the task. We conclude that desire-related lexical decision priming could provide a useful objective correlate of proneness to desire-related intrusions.     

The affective regulation of cognitive priming

Semantic and affective priming are classic effects observed in cognitive and social psychology, respectively. The authors discovered that affect regulates such priming effects. In Experiment 1, positive and negative moods were induced before one of three priming tasks; evaluation, categorization, or lexical decision. As predicted, positive affect led to both affective priming (evaluation task) and semantic priming (category and lexical decision tasks). However, negative affect inhibited such effects. In Experiment 2, participants in their natural affective state completed the same priming tasks as in Experiment 1. As expected, affective priming (evaluation task) and category priming (categorization and lexical decision tasks) were observed in such resting affective states. Hence, the authors conclude that negative affect inhibits semantic and affective priming. These results support recent theoretical models, which suggest that positive affect promotes associations among strong and weak concepts, and that negative affect impairs such associations (Clore & Storbeck, 2006; Kuhl, 2000).     

Semantic priming and identification of near threshold primes in a lexical decision task

Three experiments examined both the impact of semantic analysis of 50-msec, masked visual primes on a target response and the impact of semantic analysis of the target on a prime response. The first two experiments used a prime-target interval of 1000 msec. In Experiment 1, subjects reported the identity of each prime: (a) after a lexical decision about the target, (b) both before and after a lexical decision, or (c) after a target detection response. Prime report after both types of target response showed retroactive priming in which report was facilitated by related targets and inhibited by unrelated targets. Analyses of lexical decision latency and accuracy conditionalized on prime report showed that semantic priming was restricted to reported related primes. In Experiment 2, subjects made no overt response to the primes. Priming was conditionalized on recognition of the primes on a subsequent test. The pattern was the same as Experiment 1: There was priming only for recognized primes; recognition memory showed a pattern consistent with retroactive priming. Experiment 3 also conditionalized priming on recognition performance but used a prime-target interval of only 250 msec. Again, semantic priming was found only for recognized primes, and recognition memory revealed retroactive priming. Retroactive priming indicates an interdependency between prime and target processing that needs to be incorporated into models of semantic priming.     

The unbearable lightness of priming

Repetition priming from text to isolated words has been difficult to observe. One explanation for this difficulty is that previous attempts to observe this type of priming have utilised conditions that normally reduce priming. Two experiments were conducted to evaluate this hypothesis. Experiment 1 involved participants being presented with words in isolation and in text passages. The words were then presented again in a lexical decision test. Results indicated that priming occurred as a result of exposure to both isolated words and words in text, although priming was greater in the word-word condition. Experiment 2 investigated whether priming occurred in a lexical decision test on words that had been read prior to the test in Milan Kundera's novel "The Unbearable Lightness of Being." There was some evidence that participants who had read the book recently were faster at lexical decision to words from the book than participants who had not read the book. The two experiments therefore indicate that priming can occur from text to isolated words, although it is smaller in magnitude to that observed from word to word. Reasons for this difference, as suggested by Kirsner and Speelman (J. Exp. Psychol.: Learn. Mem. Cogn. 22 (1996) 563) model of repetition priming, are discussed.     

Three-step priming in lexical decision

In two experiments, we investigated mediated two-step priming (e.g., from LION to STRIPES via TIGER) and three-step priming (e.g., from MANE to STRIPES via LION and TIGER). Experiment 1 showed robust two-step priming in the double lexical decision task. In Experiment 2, we tested for three-step priming and investigated the possibility that it is not association strength based on free association, but frequency of co-occurrence, that causes three-step priming. Co-occurrence has been proposed as a measure of familiarity and semantic relatedness. Significant three-step priming was obtained. Lexical co-occurrence could not account for the effect. However, a more global measure of semantic similarity that includes the similarity of the contexts in which concepts occur revealed that the three-step pairs were semantically related. If this global measure provides a proper estimate of the semantic relatedness of our items, then three-step priming is consistent not only with spreading activation models, but also with distributed memory models and the compound cue model.     

The paradoxical effects of suppressing anxious thoughts during imminent threat

In line with the ironic processing theory of Wegner (Psychol. Rev. 101 (1994) 34), it is often argued that the suppression of anxiety-related thoughts results in a paradoxical increase of anxiety and thought intrusions, both after and during the thought suppression. In a sample of undergraduate students (14 men, 18 women), we investigated the effects of suppressing anxious thoughts about an imminent painful electrocutaneous stimulus. During thought suppression, self-reported anxiety and frequency of anxious thoughts did not increase, and duration of anxious thoughts decreased. After thought suppression, participants experienced an increase in self-reported anxiety and the frequency of anxious thoughts. There was no effect upon thought duration. The results support the idea that suppression of anxiety-related thoughts may result in a paradoxical increase in anxiety, and may cause and/or maintain anxiety problems.     

Suppression of intrusive thoughts and working memory capacity in repressive coping

Previous research using a thought suppression paradigm found that repressors are more skilled in suppressing anxious autobiographical thoughts than low anxious, high anxious, and defensive high anxious people. Another line of research showed that individual differences in working memory capacity are related to the ability to intentionally suppress intrusive thoughts. This study aimed at combining these findings and sought to investigate whether repressors' superior ability to suppress intrusive thoughts is related to a larger working memory capacity. Results indicate that in a thought suppression paradigm, repressors report fewer intrusive thoughts for their most anxious experiences than participants in the 3 other subgroups. Furthermore, the superior ability of repressors to avoid intrusive thoughts can be explained largely by their higher working memory capacity.