Reduced directed forgetting for negative words suggests schizophrenia-related disinhibition of emotional cues

Active forgetting and neuropsychiatric diseases

Recent and pioneering animal research has revealed the brain utilizes a variety of molecular, cellular, and network-level mechanisms used to forget memories in a process referred to as "active forgetting". Active forgetting increases behavioral flexibility and removes irrelevant information. Individuals with impaired active forgetting mechanisms can experience intrusive memories, distressing thoughts, and unwanted impulses that occur in neuropsychiatric diseases. The current evidence indicates that active forgetting mechanisms degrade, or mask, molecular and cellular memory traces created in synaptic connections of "engram cells" that are specific for a given memory. Combined molecular genetic/behavioral studies using Drosophila have uncovered a complex system of cellular active-forgetting pathways within engram cells that is regulated by dopamine neurons and involves dopamine-nitric oxide co-transmission and reception, endoplasmic reticulum Ca2+ signaling, and cytoskeletal remodeling machinery regulated by small GTPases. Some of these molecular cellular mechanisms have already been found to be conserved in mammals. Interestingly, some pathways independently regulate forgetting of distinct memory types and temporal phases, suggesting a multi-layering organization of forgetting systems. In mammals, active forgetting also involves modulation of memory trace synaptic strength by altering AMPA receptor trafficking. Furthermore, active-forgetting employs network level mechanisms wherein non-engram neurons, newly born-engram neurons, and glial cells regulate engram synapses in a state and experience dependent manner. Remarkably, there is evidence for potential coordination between the network and cellular level forgetting mechanisms. Finally, subjects with several neuropsychiatric diseases have been tested and shown to be impaired in active forgetting. Insights obtained from research on active forgetting in animal models will continue to enrich our understanding of the brain dysfunctions that occur in neuropsychiatric diseases.

Attentional engagement and inhibitory control according to positive and negative symptoms in schizophrenia: An emotional antisaccade task

Despite schizophrenia (SZ) is characterized by a high psychopathological heterogeneity, the underlying psychological mechanisms that result in different clinical profiles are unclear. This study examined the cognitive processing of emotional faces (angry, happy, neutral, and sad) by means of assessing inhibitory control (antisaccade task) and attentional engagement (prosaccade task) with the eye-tracking paradigm. Firstly, two clinical SZ subgroups classified according to the predominance of positive (PSZ; n = 20) or negative symptoms (NSZ; n = 34) and a control group of 32 individuals were compared. Secondly, the association between prosaccade and antisaccade measurements and the severity of positive and negative symptoms were analyzed. The PSZ group showed slower antisaccades when angry faces were displayed, and higher positive symptoms were associated with slower prosaccade latencies to ones. Conversely, the NSZ group made overall slower prosaccades with an emotional advantage for angry faces, and higher negative symptoms were associated with faster antisaccade latencies to ones. Hence, whereas positive SZ profile is related to a lack of attentional engagement and an impaired inhibitory control to threatening information; negative SZ profile is linked to a lack of attentional engagement to faces, mainly with non-threat ones, and with an advantage to ignore distracting threatening stimuli. These findings support affective information-processing theories suggesting a hypersensitivity to threat for positive SZ profiles, and a desensitization to socio-emotional information for negative ones. Consequently, characterizing psychological mechanisms of SZ may allow improving current treatments to threat management when positive symptoms are predominant, or emotion sensitization when negative symptoms prevail.

Forgetting Unwanted Memories: Active Forgetting and Implications for the Development of Psychological Disorders

Intrusive memories are a common feature of many psychopathologies, and suppression-induced forgetting of unwanted memories appears as a critical ability to preserve mental health. In recent years, biological and cognitive studies converged in revealing that forgetting is due to active processes. Recent neurobiological studies provide evidence on the active role of main neurotransmitter systems in forgetting, suggesting that the brain actively works to suppress retrieval of unwanted memories. On the cognitive side, there is evidence that voluntary and involuntary processes (here termed "intentional" and "incidental" forgetting, respectively) contribute to active forgetting. In intentional forgetting, an inhibitory control mechanism suppresses awareness of unwanted memories at encoding or retrieval. In incidental forgetting, retrieval practice of some memories involuntarily suppresses the retrieval of other related memories. In this review we describe recent findings on deficits in active forgetting observed in psychopathologies, like post-traumatic stress disorder, depression, schizophrenia, and obsessive-compulsive disorder. Moreover, we report studies in which the role of neurotransmitter systems, known to be involved in the pathogenesis of mental disorders, has been investigated in active forgetting paradigms. The possibility that biological and cognitive mechanisms of active forgetting could be considered as hallmarks of the early onset of psychopathologies is also discussed.

What can directed forgetting tell us about clinical populations?

This paper reviews and critically assesses the implications of directed forgetting (DF) research on clinical populations. We begin by reviewing the typical methods and results of the item method and list method directed forgetting procedures and provide best practice recommendations for future studies using clinical populations. Next, we note that DF was often interpreted as being due to inhibition, and when clinical populations showed impaired directed forgetting, it was treated as evidence in inhibitory control difficulties. However, inhibition may not be the cause of DF effects, based on current understanding of these cognitive tasks. We instead suggest that item method DF is tied to attentional control, which might include inhibitory mechanisms (or might not). In contrast, list method DF is tied to two forms of memory control: control of mental context (indicated by effective forgetting of List 1), and changes in the strategies used to remember (indicated by better learning of List 2). We review the current state of the clinical DF literature, assess its strength based on our best practice recommendations, and call for more research when warranted.

Many ways to forget - Neurophysiology of directed forgetting mechanisms in schizophrenia

Numerous studies have shown dysfunctional mechanism of interaction between bottom-up emotional and top-down cognitive processes in persons with schizophrenia (SCZ). During the emotional directed forgetting (DF) paradigm participants have to apply volitional mechanisms to resist automatic emotional enhancement of the memory. Here we sought to compare mechanisms underlying emotional DF in SCZ and in healthy persons (HC). Eighteen SCZ and eighteen HC completed a DF paradigm with neutral and negative pictures. EEG was recorded during study and test phase of the task. We analyzed both the behavioral outcomes and event-related potential components, indicating emotional enhancement of memory (Late Positive Potential elicited by pictures) and DF strategies (N2/P3 elicited by forget/remember cues during study-phase; "old/new" and "reversed old/new" effects during test-phase of the task). Directed forgetting effects and emotional enhancement of memory were observed in both groups, even despite overall lower recognition rates in SCZ. Furthermore, cue presentation elicited similar pattern of N2/P3s in SCZ and in HC. However, "reversed old/new" effect was observed only in HC for negative stimuli. Patients may show similar reaction to affective stimuli as healthy controls during the emotional DF task. However, further investigation is needed to elicit the specific mechanisms underlying the DF strategies in SCZ.

Mnemonic emotion regulation: a three-process model

Emotion regulation comprises attempts to influence when and how emotions are experienced and expressed. It has mostly been conceived of as proactive (e.g. situation selection) or reactive (e.g. attentional distraction), but it may also be retroactive and involve memory. I term such past-oriented activity mnemonic emotion regulation and propose that it involves increasing or decreasing access to or altering the characteristics of a memory. People may increase access to a memory and make it more likely that it will be retrieved in the future, for example by rehearsing a pleasant memory. They may decrease access to a memory and make it less likely that intrusions will be experienced in the future, for example by repeatedly trying to stop an unpleasant memory from being retrieved. Finally, people may alter the characteristics of a memory and change its content or context, for example by replacing a negative impression with a productive interpretation. I discuss how mnemonic emotion regulation may be instigated (e.g. via elaborate rehearsal) as well as the different motives (e.g. hedonic motives) people may have for engaging in regulation. Also, I discuss possible benefits of, variations in, and improvements of mnemonic emotion regulation.

World Health Organization disability assessment schedule 2.0: An international systematic review

PURPOSE

This systematic review examines research and practical applications of the World Health Organization Disability Assessment Schedule (WHODAS 2.0) as a basis for establishing specific criteria for evaluating relevant international scientific literature. The aims were to establish the extent of international dissemination and use of WHODAS 2.0 and analyze psychometric research on its various translations and adaptations. In particular, we wanted to highlight which psychometric features have been investigated, focusing on the factor structure, reliability, and validity of this instrument.

METHOD

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodology, we conducted a search for publications focused on "whodas" using the ProQuest, PubMed, and Google Scholar electronic databases.

RESULTS

We identified 810 studies from 94 countries published between 1999 and 2015. WHODAS 2.0 has been translated into 47 languages and dialects and used in 27 areas of research (40% in psychiatry).

CONCLUSIONS

The growing number of studies indicates increasing interest in the WHODAS 2.0 for assessing individual functioning and disability in different settings and individual health conditions. The WHODAS 2.0 shows strong correlations with several other measures of activity limitations; probably due to the fact that it shares the same disability latent variable with them. Implications for Rehabilitation WHODAS 2.0 seems to be a valid, reliable self-report instrument for the assessment of disability. The increasing interest in use of the WHODAS 2.0 extends to rehabilitation and life sciences rather than being limited to psychiatry. WHODAS 2.0 is suitable for assessing health status and disability in a variety of settings and populations. A critical issue for rehabilitation is that a single "minimal clinically important .difference" score for the WHODAS 2.0 has not yet been established.

The representational consequences of intentional forgetting: Impairments to both the probability and fidelity of long-term memory

We investigated whether intentional forgetting impacts only the likelihood of later retrieval from long-term memory or whether it also impacts the fidelity of those representations that are successfully retrieved. We accomplished this by combining an item-method directed forgetting task with a testing procedure and modeling approach inspired by the delayed-estimation paradigm used in the study of visual short-term memory (STM). Abstract or concrete colored images were each followed by a remember (R) or forget (F) instruction and sometimes by a visual probe requiring a speeded detection response (E1-E3). Memory was tested using an old-new (E1-E2) or remember-know-no (E3) recognition task followed by a continuous color judgment task (E2-E3); a final experiment included only the color judgment task (E4). Replicating the existing literature, more "old" or "remember" responses were made to R than F items and RTs to postinstruction visual probes were longer following F than R instructions. Color judgments were more accurate for successfully recognized or recollected R than F items (E2-E3); a mixture model confirmed a decrease to both the probability of retrieving the F items as well as the fidelity of the representation of those F items that were retrieved (E4). We conclude that intentional forgetting is an effortful process that not only reduces the likelihood of successfully encoding an item for later retrieval, but also produces an impoverished memory trace even when those items are retrieved; these findings draw a parallel between the control of memory representations within working and long-term memory.

Neurophysiological correlates of emotional directed-forgetting in persons with Schizophrenia: An event-related brain potential study

BACKGROUND

Recent research has shown that patients with schizophrenia (SCZ) exhibit reduced directed forgetting (DF) for negative words, suggesting impaired ability to instantiate goal-directed inhibition in order to suppress a competing, emotion-driven responses (i.e., emotional memory enhancement). However, disrupted inhibition is not the only possible mechanism by which patients could manifest reduced emotional DF. Therefore, the primary objective of the current study was to use event-related brain potential (ERP) recordings to investigate alternative hypotheses.

METHODS

ERPs were recorded while patients and controls completed an item-method DF paradigm using negative and neutral words. The N2 indexed goal-directed inhibition of to-be-forgotten items. The late positive potential (LPP) indexed emotional memory enhancement for negative study items. The P300 indexed selective rehearsal of to-be-remembered items.

RESULTS

The SCZ group exhibited a reduced DF effect overall, but this was not modulated by emotion. N2 amplitude at anterior sites was larger for forget versus remember cues in the control group only, but this effect was not modulated by emotion. LPP amplitude was greater for negative versus neutral words in both groups, independent of region. P300 amplitude at posterior sites was greater for remember versus forget cues in the control group only.

DISCUSSION

These data suggest that reduced DF in SCZ may be due, in part, to both diminished goal-directed inhibition of to-be-forgotten items and reduced selective rehearsal of to-be-remembered items. However, these data do not support the hypothesis that goal-directed, inhibitory processes are disrupted by competing, emotion-driven processes in SCZ. Patients' ERP data also suggested that they did not exhibit disproportionately heightened encoding of emotional stimuli, nor did they have deficient selective rehearsal of to-be-remembered emotional items.

Inhibiting reactions to emotional versus non-emotional response cues in schizophrenia: Insights from a motor-process paradigm

Recent models of schizophrenia suggest deficient use of contextual response cues when confronted with countermanding emotional cues. It is important to clinically validate these models by testing patients diagnosed with schizophrenia on tasks with competing emotional and contextual response determinants. Control and schizophrenia groups completed a novel task that elicited motor responses consistent with, or in opposition to, pre-potent emotional actions (i.e., approach vs. avoidance). An analogous non-emotional task was also used to examine cue-conflict impairment more generally. The groups demonstrated statistically equivalent performance decrements on incongruent versus congruent trials on both tasks. However, within the schizophrenia group, the incongruency effect was significantly greater in the emotional versus non-emotional task. These data suggest that, while patients with schizophrenia were able to employ contextual response cues to override competing emotional responses, they were slower to resolve emotional versus non-emotional response conflict. When patients were subdivided according to the presence or absence of disorganized symptoms, this effect was confined to patients with disorganized symptoms.

Binding action and emotion in first-episode schizophrenia

BACKGROUND/AIMS

Several components of social cognition are compromised in schizophrenia (SCZ) from the early stage of the illness. In this study we first investigated whether mirror neuron-driven embodied simulation (mnES) is altered in first-episode SCZ. Second, we tested whether emotional cues impact on the mnES in SCZ patients.

METHODS

Twenty-two SCZ patients and 22 healthy controls (HCs) observed goal-related actions in either a neutral or emotional context during functional magnetic resonance imaging scanning.

RESULTS

Observation of neutral action elicited a lower activity in the frontoparietal network in SCZ patients, as compared to HCs. Particularly, activation in the left inferior parietal lobule in response to the same condition negatively correlated with patients' self-experience disturbances. Moreover, observation of an action performed by an angry agent produced poorer neural activity in the right anterior insula in SCZ patients as compared to HCs. This difference was mostly due to the negative β-values shown by SCZ patients, which positively correlated with their empathy scores. No differences were found contingent upon the observation of an action performed by a happy agent.

CONCLUSION

Our results show that emotional cues allow SCZ patients to partially recover mnES. However, their understanding of the emotional components of the actions of others will likely remain deficient.