Implicit and explicit memory bias in depressed and non depressed subjects

Abstract

Two experiments were carried out to investigate a possible mood-congruent memory bias in explicit memory (free-recall test) and implicit memory (word-stem completion task) for positive and negative words in depressed and non depressed college students. A comparison of implicit and explicit mood-congruent memory bias should help to reveal cognitive processes involved in this effect. The results of both studies indicated that depressed subjects showed a memory bias not only on the traditional explicit memory task, but on the implicit memory task as well. The theoretical implications of these results are discussed.     

Autobiographical memory and clinical anxiety

Abstract

Previous experiments on the recall of threatening and neutral information in clinically anxious subjects have yielded mixed results. The present study assessed autobiographical memory in patients with generalised anxiety disorder (GAD), and normal controls. Subjects were first presented with neutral cue words and asked to respond with any personal memory. GAD subjects judged the content of their own memories as more consistent with anxious mood, and less consistent with pleasant mood, than that reported by controls. Subjects were then again presented with neutral cue words, but with instructions to provide either “anxious” or “nonanxious” personal memories, on specified trials. Significant interactions between group and instruction condition indicated that anxious subjects recalled more anxiety-evoking memories, and recalled them more rapidly, relative to controls. Ratings by blind judges did not support the hypothesis that this apparent difference in the content of autobiographical recall was an artefact due to anxious subjects labelling memories as being more anxiety evoking than would controls. Possible explanations of the findings, and reasons for the apparent discrepancy between these and earlier results, are discussed.     

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.     

Trait anxiety,anxious mood,and threat detection

Abstract

Subjects were required to detect either an angry or a happy target face in a stimulus array of 12 photographs. It was found with neutral distractor faces that those high in trait anxiety detected angry faces faster than did low trait-anxious subjects, but the two groups did not differ in their speed of detection of happy targets. In addition, high trait-anxious subjects detected happy target faces slower than low trait-anxious subjects when the distractor faces were angry. Comparable findings were obtained whether or not there was anxious mood induction. It was concluded that high trait-anxious individuals have facilitated detection and processing of environmental threat relative to low trait-anxious subjects, which enhance performance when the target is threatening, but which impair performance when the distractors are threatening.     

Ego-threat interpretive bias in test anxiety: On-line inferences

Abstract

The hypothesis that test anxiety is associated with an on-line bias towards threatening interpretations of ambiguous information was explored by means of a lexical decision task. Ambiguous sentences (concerned with ego-threat, physical-threat, or non-threat events) were presented to high- and low- test-anxiety subjects. Sentences were followed by a disambiguating word or a very wordlike corresponding nonword, which either confirmed or disconfirmed the threat implied by the sentence. A control condition involved the presentation of words and nonwords alone, without being primed by the sentences. Results indicated that there were no differences in lexical decision times as a function of test anxiety when words and nonwords were presented alone. In contrast, when they were primed, high-anxiety subjects took longer to respond correctly to the ego-threat confirming nonword, and to the ego-threat disconfirming word, compared with low-anxiety subjects; likewise, high-anxiety subjects responded faster to the ego-threat confirming word than to the ego-threat disconfirming word, compared with low-anxiety subjects. These results suggest that test anxious individuals are likely to draw inferences with an ego-threat meaning, but not with a physical-threat meaning, when reading ambiguous sentences.     

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.     

Attention to Positive and Negative Social-Evaluative Words: Investigating the Effects of Social Anxiety,Trait Anxiety and Social Threat

The study investigated how attention to negative (threatening) and positive social-evaluative words is affected by social anxiety, trait anxiety and the expectation of social threat. High and low socially anxious individuals carried out a modified dot-probe task either while expecting to give a speech or under non-threatening conditions. High socially anxious individuals showed no significant attentional bias towards or away from social-evaluative words. This result significantly contrasted with an identical design that showed avoidance of emotional faces in high socially anxious participants drawn from the same population (Mansell et al ., 1999). Participants who expected to give a speech showed less attentional avoidance of negative and positive social-evaluative words. High trait anxiety was associated with selective attention to negative relative to positive social-evaluative words, consistent with earlier findings of attention to threat cues in high trait-anxious individuals. Implications for designing attention tasks and attentional bias across different dimensions of anxiety are discussed.     

Trait congruence in the study of the cognitive consequences of emotional arousal

This study investigated the possible influence of mood and emotional vulnerability on recall. Mood was induced by projecting highly emotionally laden slides. In the first experiment, 64 female subjects, rated low or high on emotional vulnerability, were tested on recall of mood-congruent, mood-incongruent and neutral words, under mood induction and non-mood induction conditions. Emotionally low-vulnerable subjects recalled more mood-congruent than mood-incongruent words in the mood induction condition, whereas the opposite was the case in the non-mood induction condition. Highly vulnerable subjects recalled more mood-congruent than mood-incongruent words in the non-mood induction condition and fewer mood-congruent words in the mood induction compared with non-mood induction condition. The results are discussed in terms of ‘mood congruence’ (to explain low-vulnerable (LV) subjects' performance) and in terms of ‘trait congruence’ (to explain highly-vulnerable (HV) subjects' performance). In a second experiment, which investigated LV and HV subjects' galvanic skin responses to highly- and low-emotionally laden slides, the highest values were those for HV subjects when exposed to emotional slides. The different activation of LV and HV subjects led us to reconsider previous reasoning regarding mood congruence and trait congruence in the light of the inverted U theory.     

Attentional bias in anxiety: selective search or defective filtering?

Two experimental tasks were used to investigate the nature of a previously documented bias in attention associated with anxiety. Results from the first task failed to reveal any differences between anxious and nonanxious subjects, either in attention focusing or selective search for letters. The second task, with words as targets and distractors, suggested that selective search was less efficient in anxious subjects when distractors were present. Currently anxious subjects were slower than controls when required to search for the target among distractors of any type, whereas both currently anxious and recovered subjects were slower when the distractors were threatening words. It was therefore suggested that a bias favoring threat cues during perceptual search is an enduring feature of individuals vulnerable to anxiety, rather than a transient consequence of current mood state alone.     

Differential encoding of affective and nonaffective content information in trait anxiety

The relative encoding of affective and nonaffective content information in high and low trait anxious individuals was investigated. Experiment 1 (N = 35) found that, compared to Low Anxiety participants, High Anxiety participants showed relatively greater speeding of affective semantic decisions compared to nonaffective content semantic decisions. Using a similarity rating paradigm, Experiments 2 (N = 51) and 3 (N = 100) found higher levels of trait anxiety were associated with a decreased use of content information when nonaffective information was less salient than affective information. Experiment 4 (N = 100) found higher levels of trait anxiety were associated with a complementary increased use of affective information when affective information was less salient than nonaffective information. Thus, it appears that trait anxiety may be associated with a bias to encode less salient information to a greater extent when it is relevant to affect, and to a lesser extent when it is not.     

Mood-congruent free recall bias in anxiety

The present study evaluated the status of mood-congruent free recall bias in anxious individuals following incidental encoding of target words. In the first experiment, high trait anxiety individuals showed increased recall of threat-related information after an orienting task promoting lexical processing of target words. In a second experiment, both lexical and semantic orienting tasks were performed at study. In this experiment, anxious individuals displayed a mood-congruent recall bias only for target information processed at a lexical level. Theoretical and practical implications of these findings are discussed.     

Anxiety and Mood-congruent Autobiographical Memory: A Conceptual Failure to Replicate

This study further explored whether highly anxious participants exhibit a mood-congruent autobiographical memory bias, as was found in two previous studies (Burke & Mathews, 1992; Richards & Whittaker, 1990). The 74 high and low trait anxious participants retrieved personal memories to anxiety-related, neutral, and positive cue words, and were then asked to recall the original cue words. The study also explored how expression of emotional versus factual responses might affect a memory bias. On most dependent measures, no differences were found between anxiety groups. However, low anxious participants recalled more memories overall than high anxious participants. In addition, the emotions groups recalled more words at free recall than the facts groups. Findings fail to support previous studies that found an autobiographical memory bias to be associated with high anxiety, and cast more support for the mounting evidence against a mood-congruent memory bias in anxiety.     

Mood-congruent free recall bias in anxiety

The present study evaluated the status of mood-congruent free recall bias in anxious individuals following incidental encoding of target words. In the first experiment, high trait anxiety individuals showed increased recall of threat-related information after an orienting task promoting lexical processing of target words. In a second experiment, both lexical and semantic orienting tasks were performed at study. In this experiment, anxious individuals displayed a mood-congruent recall bias only for target information processed at a lexical level. Theoretical and practical implications of these findings are discussed.     

Attention allocation and habituation to anger-related stimuli during a visual search task

A substantial amount of data has accumulated demonstrating that emotionally disordered subjects are prone to bias their attention toward threatening, emotionally relevant stimuli. Little attention has been reserved for the study of cognitive processes involved in anger arousal. In the present study, we investigated whether mood-congruent attentional biases could be demonstrated in subjects of varying levels of trait anger using a visual search task. This task also assessed whether mood-congruent biases diminished with repeated exposure to specific emotion stimuli. To investigate state-trait interaction effects, a naturalistic, anger-inducing insult was administered to half the subjects. There was a positive relation between participants' level of trait anger and their degree of mood-congruent attentional bias toward anger-related cues only after an insult. As predicted, this effect diminished across blocks of trials. Aggr. Behav. 24:399–409, 1998. © 1998 Wiley-Liss, Inc.     

Anxiety and Attentional Bias: State and Trait

Abstract

MacLeod, Mathews, and Tata (1986) found that anxious patients showed a tendency to react faster to a probe stimulus that appeared in the location of a threatening visual word rather than in that of a simultaneous neutral word. In 4 experiments, a total of 104 subjects drawn from the general population were tested on different variations of this task. A relationship to anxiety was confirmed, and it was shown that this relationship did not appear on animal names that also formed a semantically similar set and had an equal probability of being followed by a probe stimulus. Although the effect is therefore dependent on the content of the word, it builds up during the experimental session and is therefore likely to be due to increasing post-attentive awareness of the presence of threatening words.

The most reliable results across experiments were found by using Trait rather than State Anxiety, and particularly by fitting a curvilinear relationship such that the exact degree of Anxiety makes little difference at low levels but becomes increasingly important at high levels. If State is used, the best relationship is found with an interaction with Trait, such that State makes more difference at high values of Trait. This means that the effect must be to some extent due to lasting personality characteristics. It is not something that happens to everybody when in a temporary state.     

Altered working memory capacity for social threat words in high versus low social anxiety

ABSTRACT

Background and objectives: Differences in working memory capacity (WMC) have been suggested in individuals with high levels of social anxiety (SA). Specifically, these individuals may preferentially maintain socially threatening material in working memory.

Design and methods: We adapted the digit span task to a series of word span tasks. We assessed WMC for lists of words that varied in terms of their threat-relatedness, in individuals either high or low in SA.

Results: Experiment 1 revealed reduced WMC for socially threatening words in those with high compared to low SA. Importantly, this relative reduction in WMC was driven by the low SA group showing expanded capacity for socially threatening words relative to neutral or generally threatening words. Furthermore, reductions in WMC for social threat were uniquely predicted by SA, and not by other theoretically related constructs such as state general anxiety, trait general anxiety, or depression. Experiment 2 showed that the semantic similarity of the words within each list was not responsible for the differences in WMC between list type or SA group.

Conclusions: Our findings suggest that individuals high in SA may fail to upregulate WMC for social information due to the activation of, or rumination upon, socially threatening concepts.     

Attentional bias to threat in clinical anxiety states

Abstract

Attentional responses to threat stimuli were assessed in anxious patients, normal controls, and subjects who had recovered from a clinical anxiety state. The main aims of the study were: (1) to replicate MacLeod, Mathews, and Tata's (1986) finding of an attentional bias to threat in currently anxious patients compared with normal control subjects; (2) to assess whether the bias is related to the predominant worries of anxious patients; and (3) to investigate whether the bias is present in recovered anxious patients. The original finding of an anxiety-related attentional bias was replicated. The results indicated that the extent to which anxious patients selectively attended to social threat words was associated with the seventy of their social worries. The attentional responses of the recovered anxious group were not significantly differentiated from those of the currently anxious or normal control groups.     

Mood congruence in childhood and recent autobiographical memory

To improve upon previous methodology, participants in musically induced happy, sad, or neutral moods were asked to recall childhood and recent autobiographical memories in response to pleasant, unpleasant, and neutral word cues. Symmetrical mood-congruent memory effects were observed when events were rated from the perspective of when they actually occurred (i.e., then), because memories rated as being unpleasant then tended to be rated as more pleasant now. Finally, pleasant and unpleasant cue words facilitated retrieval of childhood memories more than did neutral cues. These findings suggest that symmetrical mood congruence can be observed when accounting for such factors as the valence of retrieval cues and the perspective from which experiences are rated, given that memories appear to undergo change in affective labelling.