Memory of faces: a slow wave ERP study of major depression

This study examined slow wave (SW) event-related brain potential (ERP) amplitudes in response to happy, neutral, and sad faces during a working memory task to further identify the associated component processes and physiological changes of mood-congruent memory biases in individuals with and without major depression. The results suggest that individuals with and without a diagnosis of major depressive disorder (MDD) differentially maintain valenced facial information in their working memory. Specifically, the nondepressed individuals displayed a marked reduction in SW amplitude to the negative faces. Individuals with MDD exhibited equivalent SW amplitudes for positive and negative facial stimuli. Results are discussed in terms of avoidance coping, previous ERP studies of working memory, and facial recognition deficits in individuals with MDD.     

Neurophysiological indices of free recall memory biases in major depression: The impact of stimulus arousal and valence

This study examined differential impact of the valence and arousal characteristics of stimuli on memory biases and brain activity in major depressive disorder (MDD) and non-depressed control participants. P300 and slow wave (SW) components of the event-related brain potential (ERP) were recorded in 18 MDD and 18 control individuals during the encoding of positive and negative, high and low arousal words in a free recall task. Control participants demonstrated expected enhanced memory for positive stimuli that was accompanied by a corresponding increase in SW ERP components. These effects were not seen in the MDD participants. Rather, memory biases for negative information in MDD were only observed for low arousal words and were not reflected in ERP amplitudes. This study suggests that the inconsistency in the MDD memory bias literature may be related to the arousing nature of the stimuli incorporated in the study.     

Biases in affective forecasting and recall in individuals with depression and anxiety symptoms

The authors used experience sampling to investigate biases in affective forecasting and recall in individuals with varying levels of depression and anxiety symptoms. Participants who were higher in depression symptoms demonstrated stronger (more pessimistic) negative mood prediction biases, marginally stronger negative mood recall biases, and weaker (less optimistic) positive mood prediction and recall biases. Participants who were higher in anxiety symptoms demonstrated stronger negative mood prediction biases, but positive mood prediction biases that were on par with those who were lower in anxiety. Anxiety symptoms were not associated with mood recall biases. Neither depression symptoms nor anxiety symptoms were associated with bias in event prediction. Their findings fit well with the tripartite model of depression and anxiety. Results are also consistent with the conceptualization of anxiety as a "forward-looking" disorder, and with theories that emphasize the importance of pessimism and general negative information processing in depressive functioning.     

Positive memory enhancement training for individuals with major depressive disorder

When in a negative mood state, individuals with major depressive disorder (MDD) may have difficulties recalling positive autobiographical memories in a manner that repairs that negative mood. Using cognitive bias modification techniques, investigators have successfully altered different aspects of cognition among individuals with MDD. However, little has been done to investigate the modification of positive autobiographical memory recall. This study examined the impact of a novel positive memory enhancement training (PMET) on the memories and subjective affective experiences of individuals with MDD (N = 27). Across a series of trials, participants first recalled a sad memory to elicit a negative mood state. They then recalled a happy memory and completed procedures to elicit a vivid, here-and-now quality of the memory. PMET procedures were hypothesized to promote mood repair via the recall of increasingly vivid and specific positive memories. PMET participants demonstrated improved memory specificity and greater perceived ability to “relive” positive memories. The procedures also repaired mood; PMET participants’ affect following recall of positive memories did not differ from control participants’ affect following recall of neutral memories. Results provide preliminary support for PMET as a method to improve the quality of positive memories and facilitate emotion regulation in MDD.     

Cognitive processing of emotional information in depression, panic, and somatoform disorder

Emotional Stroop tasks (subliminal/supraliminal exposures), implicit memory tasks (tachistoscopic word identification), and explicit memory tasks (free recall after incidental learning) with 4 word types (physical threat, positive, negative, and neutral words) were administered to patients with major depressive disorder (n=30), panic disorder (n=33), somatoform disorder (n=25), and healthy control participants (n=33). On the Stroop task, panic patients showed subliminal interferences for physical threat and negative words, depressive patients showed supraliminal interferences for negative words, and somatoform patients showed supraliminal interferences for physical threat words. No patient groups demonstrated implicit memory biases. On the explicit memory task, depressive and panic patients showed memory biases for negative words; somatoform patients showed biases for physical threat words.     

Retrieving positive memories to regulate negative mood: consequences for mood-congruent memory

Several researchers have suggested that mood-incongruency effects are due to a mood-regulatory process in which people retrieve positive memories to repair negative moods. The present studies tested this idea by manipulating mood-repair strategies and examining their impact on positive and negative memory retrieval. Mood-congruent retrieval occurred when participants stayed focused on events associated with their negative mood; mood-incongruent retrieval occurred when participants engaged in positive reappraisal (when they reinterpreted events as having positive outcomes). The effects of these strategies on memory retrieval also interacted with personality traits related to negative mood regulation. Individuals high in such traits showed stronger mood-incongruent memory than did individuals low in negative mood-regulation traits. Discussion focuses on integrating mood-regulatory variables and personality variables into existing mood-congruency theories (e.g., associative network models).     

An examination of mood effects on positive alcohol expectancies among undergraduate drinkers

Alcohol expectancies have been found to be related to both alcohol use and abuse. To date, very little research has examined whether state biases known to affect the recall and endorsement of other types of information can influence alcohol expectancies. Mood-congruent memory theory and coping theory are reviewed, and are found to make opposing predictions regarding the relationship between state negative and positive affect and endorsement of positive alcohol expectancies. Study 1 (n = 121 undergraduate drinkers) used a correlational approach to show that negative affect predicted increased endorsement of positive alcohol expectancies. Study 2 (n = 55 undergraduate drinkers) used an experimental approach to show that participants assigned to a negative mood induction endorsed more positive alcohol expectancies than participants assigned to a positive mood induction. Together, these findings suggest that state negative affect can produce transient changes making alcohol use appear to be an attractive coping strategy.     

Cognitive inhibition in depression

Cognitive inhibition is a key mechanism in the regulation of emotion. There is emerging evidence that depression is characterized by deficits in the inhibition of mood-congruent material. These deficits could result in prolonged processing of negative, goal-irrelevant aspects of presented information thereby hindering recovery from negative mood and leading to the sustained negative affect that characterizes depressive episodes. Indeed, it has been suggested that deficits in cognitive inhibition lie at the heart of memory and attention biases in depression, and set the stage for ruminative responses to negative events and negative mood states. A ruminative response style results in a heightened vulnerability to experience episodes of major depression. Recent research has demonstrated that deficient inhibition of negative material is associated with heightened rumination. In this article, we review the depression literature with a focus on studies that investigate cognitive inhibition in depressed participants and in participants who report a history of major depressive episodes. In addition, we summarize neurobiological findings that indicate a strong relation between depression and deficits in inhibition and we take a closer look at the relation of inhibition, rumination and mood regulation.     

Systems of coping associated with dysphoria, anxiety and depressive illness: a multivariate profile perspective

As numerous coping strategies to deal with stressors can be used concurrently or sequentially, it may be productive to consider coping from a broad, systemic perspective. Using profile analysis and multivariate techniques, we demonstrated that coping profiles comprising multiple strategies distinguished between various mood states (dysphoria, anxiety, major depression, dysthymia and obsessive-compulsive disorder (OCD)). Generally, affective disturbances were associated with increased levels of rumination, cognitive distraction and emotion-focused coping (emotional expression, other-blame, self-blame, emotional containment and passive resignation) coupled with diminished problem solving and social support seeking. These coping profiles, however, varied as a function of anxiety vs. dysphoria, and severity of dysphoric symptoms, although the profile of dysphoric individuals was similar to that of clinically diagnosed dysthymic and major depressive patients. While coping profiles were generally stable over time (6 months), improvement or deterioration of mood was accompanied by corresponding alterations of coping profiles. Importantly, coping profile was not simply a correlate of dysphoric mood, but was also found to be an antecedent condition that favored the evolution of more severe affective problems. It is suggested that a multidimensional approach may prove useful in understanding coping as a dynamic system, and may have implications for clinical intervention.     

Prevention of depression among Icelandic adolescents

Major depression and dysthymia are frequent, debilitating, and chronic disorders, whose highest rate of initial onset is during the late adolescent years. The effectiveness of a program designed to prevent an initial episode of major depression or dysthymia among adolescents was investigated. Participants were 171 fourteen-year-old “at risk” Icelandic adolescents who were randomly assigned to a prevention program or a treatment-as-usual assessment only control group. They were identified as “at risk” by reporting the presence of depressive symptoms or a negative attributional style. The program was based on a developmental psychosocial model of enhancement of resilience to factors associated with the occurrence of mood disorders. The results indicated that the prevention program resulted in a significantly lower rate of major depression and dysthymia than did the control group. The study demonstrated that school personnel in the school setting can implement such prevention programs.     

Unconscious memory bias in depression: perceptual and conceptual processes

Mood-congruent memory (MCM) bias in depression was investigated using 4 different implicit memory tests. Two of the implicit tests were perceptually driven, and 2 were conceptually driven. Depressed participants and nondepressed controls were assigned to 1 of 4 implicit memory tests after studying positive and negative adjectives. Results showed no MCM bias in the perceptually driven tests. MCM was demonstrated in 1 of the conceptually driven tests, but only for adjectives that were conceptually encoded. Results support the theory that mood-congruent processes in depression are limited to conceptual processing. However, activation of conceptual processes may not be sufficient for demonstrating mood congruency.     

Cognitive and neural consequences of memory suppression in major depressive disorder

Negative biases in cognition have been documented consistently in major depressive disorder (MDD), including difficulties in the ability to control the processing of negative material. Although negative information-processing biases have been studied using both behavioral and neuroimaging paradigms, relatively little research has been conducted examining the difficulties of depressed persons with inhibiting the retrieval of negative information from long-term memory. In this study, we used the think/no-think paradigm and functional magnetic resonance imaging to assess the cognitive and neural consequences of memory suppression in individuals diagnosed with depression and in healthy controls. The participants showed typical behavioral forgetting effects, but contrary to our hypotheses, there were no differences between the depressed and nondepressed participants or between neutral and negative memories. Relative to controls, depressed individuals exhibited greater activity in right middle frontal gyrus during memory suppression, regardless of the valence of the suppressed stimuli, and differential activity in the amygdala and hippocampus during memory suppression involving negatively valenced stimuli. These findings indicate that depressed individuals are characterized by neural anomalies during the suppression of long-term memories, increasing our understanding of the brain bases of negative cognitive biases in MDD.     

Attachment‐related expectations and mother‐referent memory bias in middle childhood

Understanding the cognitive processing of attachment‐relevant information has become a major focus of attachment research. Previous research demonstrated links between attachment and memory for attachment‐related information, but results were contradictory and did not control for mood‐effects. The current study aimed to provide a conceptual framework to capture inconsistencies. A straightforward memory bias hypothesis was derived and tested. Fifty children (aged 10–12) completed questionnaires assessing confidence in maternal support and depressive symptoms, and a memory task in which they recalled positive and negative words that referred to previous interactions with mother. Less confidence in maternal support and more depressive symptoms were linked to a more negative mother‐related memory bias. The effect of confidence in maternal support remained marginally significant when controlling for depressive symptoms, explaining the initial effect of depressive symptoms. These findings support attachment theory's hypothesis that attachment‐relevant information is processed in an attachment expectation‐congruent way.     

The role of controlled attention on recall in major depression

Information processing biases are hallmark features of major depressive disorder (MDD). Depressed individuals display biased memory and attention for negative material. Given that memory is highly dependent on attention for initial encoding, understanding the interplay of these processes may provide important insight into mechanisms that produce memory biases in depression. In particular, attentional control—the ability to selectively attend to task-relevant information by both inhibiting the processing of irrelevant information and disengaging attention from irrelevant material—may be one area of impairment in MDD. In the current study, clinically depressed (MDD: n = 15) and never depressed (non-MDD: n = 22) participants' line of visual gaze was assessed while participants viewed positive and negative word pairs. For each word pair, participants were instructed to attend to one word (target) and ignore one word (distracter). Free recall of study stimuli was then assessed. Depressed individuals displayed greater recall of negatively valenced target words following the task. Although there were no group differences in attentional control in the context of negative words, attention to negative targets mediated the relationship between depression status and recall of negative words. Results suggest a stronger link between attention and memory for negative material in MDD.     

Emotion regulation in depression: Examining the role of cognitive processes

Sustained negative affect is a hallmark feature of depressive episodes. The ability to regulate emotional responses to negative events may therefore play a critical role in our understanding of this debilitating disorder. Individual differences in cognitive processes such as attention, memory, and interpretation may underlie difficulties in emotion regulation and numerous studies have identified cognitive biases and deficits that characterise depressed people. Few studies, however, have explicitly linked these biases to the difficulties in emotion regulation that are associated with depression. In this paper we discuss relations among cognitive processes and emotion regulation and review the depression literature to identify cognitive biases and deficits that may underlie maladaptive responses to negative events and mood states. Our review suggests that difficulties in the disengagement from negative material, memory biases, and deficits in cognitive control are frequently observed in depressive disorders and may be associated with the use of maladaptive emotion regulation strategies, such as rumination. These biases may also be related to difficulties implementing strategies that are effective for non-depressed people, such as recall of mood-incongruent material and reappraisal. Our review also suggests, however, that empirical studies linking cognitive biases and emotion regulation in depression are still largely missing and would present an important goal for future research in this area.     

Happiness increases verbal and spatial working memory capacity where sadness does not: Emotion,working memory and executive control

The effects of emotion on working memory and executive control are often studied in isolation. Positive mood enhances verbal and impairs spatial working memory, whereas negative mood enhances spatial and impairs verbal working memory. Moreover, positive mood enhances executive control, whereas negative mood has little influence. We examined how emotion influences verbal and spatial working memory capacity, which requires executive control to coordinate between holding information in working memory and completing a secondary task. We predicted that positive mood would improve both verbal and spatial working memory capacity because of its influence on executive control. Positive, negative and neutral moods were induced followed by completing a verbal (Experiment 1) or spatial (Experiment 2) working memory operation span task to assess working memory capacity. Positive mood enhanced working memory capacity irrespective of the working memory domain, whereas negative mood had no influence on performance. Thus, positive mood was more successful holding information in working memory while processing task-irrelevant information, suggesting that the influence mood has on executive control supersedes the independent effects mood has on domain-specific working memory.     

Individual differences in cognitive control over emotional material modulate cognitive biases linked to depressive symptoms

Deficient cognitive control over emotional material and cognitive biases are important mechanisms underlying depression, but the interplay between these emotionally distorted cognitive processes in relation to depressive symptoms is not well understood. This study investigated the relations among deficient cognitive control of emotional information (i.e. inhibition, shifting, and updating difficulties), cognitive biases (i.e. negative attention and interpretation biases), and depressive symptoms. Theory-driven indirect effect models were constructed, hypothesising that deficient cognitive control over emotional material predicts depressive symptoms through negative attention and interpretation biases. Bootstrapping analyses demonstrated that deficient inhibitory control over negative material was related to negative attention bias which in turn predicted a congruent bias in interpretation and subsequently depressive symptoms. Both shifting and updating impairments in response to negative material had an indirect effect on depression severity through negative interpretation bias. No evidence was found for direct effects of deficient cognitive control over emotional material on depressive symptoms. These findings may help to formulate an integrated understanding of the cognitive foundations of depressive symptoms.     

Autobiographical memory characteristics in depression vulnerability: formerly depressed individuals recall less vivid positive memories

The differential activation hypothesis (DAH; Teasdale, 1988) proposes that individuals who are vulnerable to depression can be distinguished from non-vulnerable individuals by the degree to which negative thoughts and maladaptive cognitive processes are activated during sad mood. While retrieval of negative autobiographical memories is noted as one such process, the model does not articulate a role for deficits in recalling positive memories. Two studies were conducted to compare the autobiographical memory characteristics of never-depressed and formerly depressed individuals following a sad mood induction. In Study 1, features of negative memories of never-depressed and formerly depressed individuals did not differ, either in neutral or sad mood. For positive memories, groups did not differ in neutral mood, but following a sad mood induction, formerly depressed individuals rated their positive memories as less vivid than their never-depressed counterparts. Study 2 examined positive autobiographical memory features more comprehensively and replicated the finding that in a sad mood formerly depressed individuals recalled less vivid positive memories than never-depressed controls. These findings suggest that the phenomenological features of positive memories could represent an important factor in depressive vulnerability, and, more broadly, that depression may be associated with a deficit in the processing of positive material.     

Embodied mood regulation: the impact of body posture on mood recovery,negative thoughts,and mood-congruent recall

Previous work has shown that a stooped posture may activate negative mood. Extending this work, the present experiments examine how stooped body posture influences recovery from pre-existing negative mood. In Experiment 1 (n?=?229), participants were randomly assigned to receive either a negative or neutral mood induction, after which participants were instructed to take either a stooped, straight, or control posture while writing down their thoughts. Stooped posture (compared to straight or control postures) led to less mood recovery in the negative mood condition, and more negative mood in the neutral mood condition. Furthermore, stooped posture led to more negative thoughts overall compared to straight or control postures. In Experiment 2 (n?=?122), all participants underwent a negative mood induction, after which half received cognitive reappraisal instructions and half received no instructions. Mood-congruent cognitions were assessed through autobiographical memory recall. Again, stooped (compared to straight) position led to less mood recovery. Notably, this was independent of regulation instruction. These findings demonstrate for the first time that posture plays an important role in recovering from negative mood.     

Autobiographical memory characteristics in depression vulnerability: Formerly depressed individuals recall less vivid positive memories

The differential activation hypothesis (DAH; Teasdale, 1988) proposes that individuals who are vulnerable to depression can be distinguished from non-vulnerable individuals by the degree to which negative thoughts and maladaptive cognitive processes are activated during sad mood. While retrieval of negative autobiographical memories is noted as one such process, the model does not articulate a role for deficits in recalling positive memories. Two studies were conducted to compare the autobiographical memory characteristics of never-depressed and formerly depressed individuals following a sad mood induction. In Study 1, features of negative memories of never-depressed and formerly depressed individuals did not differ, either in neutral or sad mood. For positive memories, groups did not differ in neutral mood, but following a sad mood induction, formerly depressed individuals rated their positive memories as less vivid than their never-depressed counterparts. Study 2 examined positive autobiographical memory features more comprehensively and replicated the finding that in a sad mood formerly depressed individuals recalled less vivid positive memories than never-depressed controls. These findings suggest that the phenomenological features of positive memories could represent an important factor in depressive vulnerability, and, more broadly, that depression may be associated with a deficit in the processing of positive material.