Cognitive control processes underlying time-based prospective memory impairment in individuals with high depressive symptomatology

Role of Prospective Memory in Obsessive Compulsive Disorder

BACKGROUND

The role of memory in obsessive-compulsive disorder (OCD) has been an area of research that has yielded mixed results, particularly in prospective memory (PM) functioning. Hence, one objective of the study was to assess PM deficits in patients with OCD. Also, research in this area has been sparse, and most researchers have used questionnaires and people with subclinical symptoms of OCD, which might have impacted the generalizability of the findings. Thus, the second objective was to assess PM functioning using a performance-based task in persons with OCD having clinical symptoms.

METHODS

This is a cross-sectional comparative study of 30 adults with OCD and 30 adults without psychiatric morbidity. The tools used were Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS), Hamilton Depression Rating Scale (HAMD), General Health Questionnaire-12 (GHQ 12), and Cambridge Prospective Memory Test (CAMPROMPT).

RESULTS

Event-based PM was significantly poor in the OCD group. In time-based PM, no significant difference was found between the groups. Three subgroups in OCD, predominantly obsessions, predominantly compulsions, and mixed types, did not differ significantly with respect to PM.

CONCLUSION

The result suggested a deficit of event-based PM in OCD, which can help understand the psychopathology of memory deficit in the clinical population and bridge the gap with respect to memory research in this domain.

Comparing different tests to detect early manifestation of prospective memory decline in aging

Objective: Prospective memory (PM) is the ability to remember to perform future intentions. Previous studies have demonstrated that, compared to a younger cohort, healthy older adults have impairments in PM. Considering the importance of early detection of age-related PM decline, the present study aims to compare the performance of healthy older adults using three well-known PM tests commonly used in clinical settings.Method: In the present study, we tested 70 older adults (65-95 years old) using the Cambridge Prospective Memory Test (CAMPROMPT), the Memory for Intentions Screening Test (MIST) and the Royal Prince Alfred Prospective Memory Test (RPA-ProMem). In order to compare performance across tests and the interaction between age and cues, we performed a linear mixed model with random intercept and random slopes. Moreover, additional mixed models with random intercept were run for analyzing the additional information provided by MIST and RPA-ProMem regarding delay responses, response modality effects and type of errors committed.Results: Our data showed a drop in PM performance as age increased detected by all three tests. Furthermore, CAMPROMPT was the most sensitive test to identify differences in PM for event-and time-based cues, at least for participants with 65-77 years old. When data were analyzed in term of delay responses, participants were more accurate for 2 min delay (MIST) and 30 in delay (RPA-ProMem). Participants were less accurate when response modality was "verbal" compared to "action" (MIST) and made more PM errors as age increased.Conclusions: Overall, the study provides important information regarding age-related PM decline and can help researchers as well as clinicians in deciding the preferred test to evaluate PM performance.

The general facilitation effect of implementation intentions on prospective memory performance in patients with schizophrenia

INTRODUCTION

Prospective memory (PM) refers to remembering to execute a planned intention in the future. It can be divided into event- and time-based, according to the nature of the PM cue. Event-based PM cues can be classified as focal or non-focal. Patients with schizophrenia (SCZ) have been found to be impaired in both event- and time-based PM. PM has been found to be improved by implementation intentions, which is an encoding strategy in the format of "if X then Y". This study examined the effect of implementation intentions on a non-focal event-based and a time-based PM task in patients with SCZ.

METHODS

Forty-two patients with SCZ and 42 healthy controls were allocated to either an implementation intention or a control PM instruction condition and were asked to complete two PM tasks.

RESULTS

Implementation intentions was found to improve performance in both the non-focal event-based and time-based PM tasks in patients with SCZ and healthy controls, with no costs to the ongoing task. The improvement in time-based PM performance in the implementation intentions condition was partially mediated by the frequency of clock checking behaviour.

CONCLUSIONS

Implementation intentions can facilitate PM performance in patients with SCZ and has the potential to be used as a clinical intervention tool.

Deficits in episodic memory and mental time travel in patients with post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by impairments in mnestic functions, especially in the domain of episodic memory. These alterations might affect different aspects of episodic memory functioning. Here we tested PTSD patients and healthy controls (matched for age, sex and education) in a newly developed virtual reality episodic memory test (VR-EMT), a test for mental time travel, episodic future thinking, and prospective memory (M3xT). In a cross-validation experiment, their performance was further evaluated in the Rivermead Behavioral Memory Test (RBMT). PTSD patients demonstrated impairments in episodic memory formation and mental time travel and showed difficulties in utilizing information from episodic memory to solve problems. Diminished attention and concentration in PTSD did not account for performance deficits in these tasks but higher levels of negative arousal were found in PTSD patients. Furthermore, performance in the VR-EMT and RBMT in PTSD patients correlated negatively with self-reported measures of stress and depression. Our results suggest that deficits in episodic memory formation and mental time travel in PTSD lead to difficulties in utilizing the content of episodic memories for solving problems in the present or to plan future behavior. Clinical implications of these findings and suggestions for cognitive-behavioral treatment of PTSD are discussed.

Disturbed retrieval network and prospective memory decline in postpartum women

Prospective memory (PM) refers to the ability to remember to execute an intended action in the future. For successful PM performance, both top-down strategic monitoring and bottom-up spontaneous retrieval processes need to be appropriately recruited. We assessed PM performance and used fMRI to discover relevant neural correlates and possible predictors for PM performance in 25 postpartum and 26 nulliparous age- and education-matched women. Postpartum women showed decreased PM performance, a higher number of nocturnal awakenings, and lower estradiol level. The postpartum women had decreased functional connectivity (FC) in the right hippocampus and ventral frontoparietal networks (FPN) during retrieval-dominant PM trials relative to maintenance-dominant ongoing trials in the PM block. On multivariate analyses, decreased FC between the right hippocampus and ventral FPN and a higher number of nocturnal awakenings were independent predictors for poor PM performance after adjusting for age, education, estradiol level, and depressive symptoms. On mediation analyses, the estradiol level was found to have an indirect effect on PM accuracy via altered FC as a mediator. This suggests that decreased FC within the spontaneous retrieval-related regions including the right hippocampus and ventral FPN, disrupted sleep rhythms, and decreased estradiol level may contribute to poor PM performance in postpartum women.

Prospective memory in obsessive compulsive disorder

Studies on the nature and extent of prospective memory impairment in patients with obsessive-compulsive disorder are relatively scarce. The present study examined prospective memory in patients with obsessive-compulsive disorder in comparison to patients with schizophrenia and healthy controls. Prospective memory was assessed using Memory for Intentions Screening Test (MIST). Further, the participants were administered Delis-Kaplan Executive Function System Tower Test, Wisconsin Card Sorting Test, and Stroop Test for assessing their planning ability, mental flexibility and cognitive inhibition, respectively. Monitoring was assessed by frequency of clock checking. Results indicated that as compared to healthy controls, the patients with obsessive-compulsive disorder performed poorly on both time- and event-based prospective memory tasks, whereas, patients with schizophrenia performed poorly on time-based prospective memory task only. Further, both the patient groups had comparable performance across time- and event-based tasks. Results of error analysis indicated that patients with obsessive-compulsive disorder mainly committed no response and task substitution errors, whereas patients with schizophrenia committed no response errors. Except monitoring, none of the neurocognitive variables correlated with time or event-based prospective memory in any group. The findings are discussed in the light of their implications for retraining of prospective memory deficits in patients with obsessive-compulsive disorder and schizophrenia.

Prospective Memory in Posttraumatic Stress Disorder

OBJECTIVES

Neuropsychological studies of posttraumatic stress disorder (PTSD) have revealed deficits in attention/working memory, processing speed, executive functioning, and retrospective memory. However, little is known about prospective memory (PM) in PTSD, a clinically relevant aspect of episodic memory that supports the encoding and retrieval of intentions for future actions.

METHODS

Here we examined PM performance in 40 veterans with PTSD compared to 38 trauma comparison (TC) veterans who were exposed to combat but did not develop PTSD. All participants were administered the Memory for Intentions Test (MIST; Raskin, Buckheit, & Sherrod, 2010), a standardized and validated measure of PM, alongside a comprehensive neurocognitive battery, structured diagnostic interviews for psychiatric conditions, and behavioral questionnaires.

RESULTS

Veterans with PTSD performed moderately lower than TC on time-based PM, with errors primarily characterized as PM failure errors (i.e., omissions). However, groups did not differ in event-based PM, ongoing task performance, or post-test recognition of PM intentions for each trial. Lower time-based PM performance was specifically related to hyperarousal symptoms of PTSD. Time-based-performance was also associated with neuropsychological measures of retrospective memory and executive functions in the PTSD group. Nevertheless, PTSD was significantly associated with poorer PM above and beyond age and performance in retrospective memory and executive functions.

DISCUSSION

Results provide initial evidence of PM dysfunction in PTSD, especially in strategic monitoring during time-based PM tasks. Findings have potential implications for everyday functioning and health behaviors in persons with PTSD, and deserve replication and future study. (JINS, 2016, 22, 724-734).

Recovery after brain damage: Is there any indication for generalization between different cognitive functions?

INTRODUCTION

The question whether recovery in various cognitive functions is supported by one or two more fundamental functions (for instance, attentional or working memory functions) is a long-standing problem of cognitive rehabilitation. One possibility to answer this question is to analyze the recovery pattern in different cognitive domains and to see whether improvement in one domain is related to performance in another domain.

METHOD

Ninety-two inpatients with stroke or other brain lesions (Barthel Index >75) were included. Neuropsychological assessment was done at the beginning and the end of a rehabilitation stay. Cognitive performance was analyzed at test and at domain level using conceptually and statistically defined composite scores for attention, immediate and delayed memory, working memory, prospective memory, and word fluency. We used regression analysis to look for generalization between cognitive domains.

RESULTS

Effect sizes of improvement varied largely (from d = 0.18 in attention and d = 1.36 in episodic memory). Age, gender, and time since injury had no impact on recovery. Impaired patients showed significantly more improvement than nonimpaired patients. Regression analysis revealed no effect of initial performance in one cognitive domain on improvements in other cognitive domains.

CONCLUSION

Significant recovery in impaired cognitive domains can be expected during neuropsychological rehabilitation. It depends more or less exclusively on improvement in the specific functions itself, and there was no evidence for generalization between cognitive domains.