Memory for emotional faces in major depression following judgement of physical facial characteristics at encoding

The aim of the present study was to establish if patients with major depression (MD) exhibit a memory bias for sad faces, relative to happy and neutral, when the affective element of the faces is not explicitly processed at encoding. To this end, 16 psychiatric out-patients with MD and 18 healthy, never-depressed controls (HC) were presented with a series of emotional faces and were required to identify the gender of the individuals featured in the photographs. Participants were subsequently given a recognition memory test for these faces. At encoding, patients with MD exhibited a non-significant tendency towards slower gender identification (GI) times, relative to HC, for happy faces. However, the GI times of the two groups did not differ for sad or neutral faces. At memory testing, patients with MD did not exhibit the expected memory bias for sad faces. Similarly, HC did not demonstrate enhanced memory for happy faces. Overall, patients with MD were impaired in their memory for the faces relative to the HC. The current findings are consistent with the proposal that mood-congruent memory biases are contingent upon explicit processing of the emotional element of the to-be-remembered material at encoding.

Memory for emotional faces in naturally occurring dysphoria and induced sadness

The aim was to establish if the memory bias for sad faces, reported in clinically depressed patients (Gilboa-Schechtman, Erhard Weiss, & Jeczemien, 2002; Ridout, Astell, Reid, Glen, & O'Carroll, 2003) generalises to sub-clinical depression (dysphoria) and experimentally induced sadness. Study 1: dysphoric (n = 24) and non-dysphoric (n = 20) participants were presented with facial stimuli, asked to identify the emotion portrayed and then given a recognition memory test for these faces. At encoding, dysphoric participants (DP) exhibited impaired identification of sadness and neutral affect relative to the non-dysphoric group (ND). At memory testing, DP exhibited superior memory for sad faces relative to happy and neutral. They also exhibited enhanced memory for sad faces and impaired memory for happy relative to the ND. Study 2: non-depressed participants underwent a positive (n = 24) or negative (n = 24) mood induction (MI) and were assessed on the same tests as Study 1. At encoding, negative MI participants showed superior identification of sadness, relative to neutral affect and compared to the positive MI group. At memory testing, the negative MI group exhibited enhanced memory for the sad faces relative to happy or neutral and compared to the positive MI group. Conclusion: MCM bias for sad faces generalises from clinical depression to these sub-clinical affective states.

Short-term memory for emotional faces in dysphoria

The study aimed to determine if the memory bias for negative faces previously demonstrated in depression and dysphoria generalises from long- to short-term memory. A total of 29 dysphoric (DP) and22 non-dysphoric (ND) participants were presented with a series of faces and asked to identify the emotion portrayed (happiness, sadness, anger, or neutral affect). Following a delay, four faces were presented (the original plus three distractors) and participants were asked to identify the target face. Half of the trials assessed memory for facial emotion, and the remaining trials examined memory for facial identity. At encoding, no group differences were apparent. At memory testing, relative to ND participants, DP participants exhibited impaired memory for all types of facial emotion and for facial identity when the faces featured happiness, anger, or neutral affect, but not sadness. DP participants exhibited impaired identity memory for happy faces relative to angry, sad, and neutral, whereas ND participants exhibited enhanced facial identity memory when faces were angry. In general, memory for faces was not related to performance at encoding. However, in DP participants only, memory for sad faces was related to sadness recognition at encoding. The results suggest that the negative memory bias for faces in dysphoria does not generalise from long- to short-term memory.

Executive function and emotional focus in autobiographical memory specificity in older adults

The current study examined the role of executive function in retrieval of specific autobiographical memories in older adults with regard to control of emotion during retrieval. Older and younger adults retrieved memories of specific events in response to emotionally positive, negative and neutral word cues. Contributions of inhibitory and updating elements of executive function to variance in autobiographical specificity were assessed to determine processes involved in the commonly found age-related reduction in specificity. A negative relationship between age and specificity was only found in retrieval to neutral cues. Alternative explanations of this age preservation of specificity of emotional recall are explored, within the context of control of emotion in the self-memory system and preserved emotional processing and positivity effect in older adults. The pattern of relationships suggests updating, rather than inhibition as the source of age-related reduction in specificity, but that emotional processing (particularly of positively valenced memories) is not influenced by age-related variance in executive control. The tendency of older adults to focus on positive material may thus act as a buffer against detrimental effects of reduced executive function capacity on autobiographical retrieval, representing a possible target for interventions to improve specificity of autobiographical memory retrieval in older adults.

Memory bias for emotional facial expressions in major depression

Sixteen clinically depressed patients and sixteen healthy controls were presented with a set of emotional facial expressions and were asked to identify the emotion portrayed by each face. They, were subsequently given a recognition memory test for these faces. There was no difference between the groups in terms of their ability to identify emotion between from faces. All participants identified emotional expressions more accurately than neutral expressions, with happy expressions being identified most accurately. During the recognition memory phase the depressed patients demonstrated superior memory for sad expressions, and inferior memory for happy expressions, relative to neutral expressions. Conversely, the controls demonstrated superior memory for happy expressions, and inferior memory for sad expressions, relative to neutral expressions. These results are discussed in terms of the cognitive model of depression proposed by Williams, Watts, MacLeod, and Mathews (1997).

Changes in brain activation during working memory and facial recognition tasks in patients with bipolar disorder with Lamotrigine monotherapy

Verbal working memory and emotional self-regulation are impaired in Bipolar Disorder (BD). Our aim was to investigate the effect of Lamotrigine (LTG), which is effective in the clinical management of BD, on the neural circuits subserving working memory and emotional processing. Functional Magnetic Resonance Imaging data from 12 stable BD patients was used to detect LTG-induced changes as the differences in brain activity between drug-free and post-LTG monotherapy conditions during a verbal working memory (N-back sequential letter task) and an angry facial affect recognition task. For both tasks, LGT monotherapy compared to baseline was associated with increased activation mostly within the prefrontal cortex and cingulate gyrus, in regions normally engaged in verbal working memory and emotional processing. Therefore, LTG monotherapy in BD patients may enhance cortical function within neural circuits involved in memory and emotional self-regulation. © 2007 Elsevier B.V. and ECNP.

Autobiographical memory specificity in response to verbal and pictorial cues in clinical depression

Background Depressed individuals have been consistently shown to exhibit problems in accessing specific memories of events from their past and instead tend to retrieve categorical summaries of events. The majority of studies examining autobiographical memory changes associated with psychopathology have tended to use word cues, but only one study to date has used images (with PTSD patients). Objective to determine if using images to cue autobiographical memories would reduce the memory specificity deficit exhibited by patients with depression in comparison to healthy controls. Methods Twenty-five clinically depressed patients and twenty-five healthy controls were assessed on two versions of the autobiographical memory test; cued with emotional words and images. Results Depressed patients retrieved significantly fewer specific memories, and a greater number of categorical, than did the controls. Controls retrieved a greater proportion of specific memories to images compared to words, whereas depressed patients retrieved a similar proportion of specific memories to both images and words. Limitations no information about the presence and severity of past trauma was collected. Conclusions results suggest that the overgeneral memory style in depression generalises from verbal to pictorial cues. This is important because retrieval to images may provide a more ecologically valid test of everyday memory experiences than word-cued retrieval.

Frontopolar cortical inefficiency may underpin reward and working memory dysfunction in bipolar disorder

Objectives. Emotional dysregulation in bipolar disorder is thought to arise from dysfunction within prefrontal cortical regions involved in cognitive control coupled with increased or aberrant activation within regions engaged in emotional processing. The aim of this study was to determine the common and distinct patterns of functional brain abnormalities during reward and working memory processing in patients with bipolar disorder. Methods. Participants were 36 euthymic bipolar disorder patients and 37 healthy comparison subjects matched for age, sex and IQ. Functional magnetic resonance imaging (fMRI) was conducted during the Iowa Gambling Task (IGT) and the n-back working memory task. Results. During both tasks, patients with bipolar disorder demonstrated a pattern of inefficient engagement within the ventral frontopolar prefrontal cortex with evidence of segregation along the medial-lateral dimension for reward and working memory processing, respectively. Moreover, patients also showed greater activation in the anterior cingulate cortex during the Iowa Gambling Task and in the insula during the n-back task. Conclusions. Our data implicate ventral frontopolar dysfunction as a core abnormality underpinning bipolar disorder and confirm that overactivation in regions involved in emotional arousal is present even in tasks that do not typically engage emotional systems. © 2012 Informa Healthcare.

Attentional inhibition determines emotional responses to unfamiliar faces

Complex abstract images that are ignored in a simple localization task are subsequently judged more negatively in an emotional evaluation task than previously unseen or attended images, suggesting that attentional inhibition may have affective consequences (Raymond, Fenske, & Tavassoli, in press). We examined the generality of this finding by asking whether inhibitory processes might also influence the generation of emotional responses to unfamiliar faces. To do this, we incorporated an emotional evaluation task within a paradigm that has been used to demonstrate long-term inhibition-of-return (IOR) of attention (Tipper, Grison, & Kessler, in press). On each 2-task trial, observers were first shown a unique pair of unfamiliar faces while performing a speeded go/no-go task. In this task, observers were required to withhold a response if there was an abrupt onset of an exogenous cue (no-go trials), and to make a response if a different stimulus was presented (go ‘catch’ trials). Following the completion of an intervening task, observers where asked to make an affective evaluation about the faces they had previously seen in the go/no-go task (e.g., Which of these people looks more friendly?). We found that observers were less likely to make positive affective responses to faces that attention had been exogenously drawn to in no-go trials than to faces to which attention had never been exogenously allocated. These results converge with our previous finding to suggest that inhibition may be associated with an episode encoded into memory, and that later retrieval acts to reinstate inhibitory processing. Importantly, our results suggest that this inhibitory processing involves affective devaluation, which may serve to encourage examination of new information.