Effectiveness of an attention- and memory-training program on neuropsychological deficits in schizophrenia

Prospective memory in adults with down syndrome

Prospective memory (PM) refers to the ability to remember one's intentions (what I must do), at the appropriate time, in the future (when I must do it). The objective of this work is to study the performance of people with Down syndrome (DS) compared to two control groups, matched by mental age and chronological age. For this purpose, an adapted version of the virtual week, which is an ecological test to simulate the functioning of PM in everyday life, was used. The results suggest that people with DS have difficulties in PM that mainly concern the binding (association) between prospective (when to do) and retrospective (what to do) components. Moreover, people with DS perform better in PM when the task is repeated and time-based. These results are discussed in light of studies conducted with other populations.

Prospective memory intervention using visual imagery in individuals with brain injury

Prospective memory deficits are common after brain injury and can create impediments to independent living. Most approaches to management of such deficits are compensatory, such as the use of notebooks or electronic devices. While these can be effective, a restorative approach, in theory, could lead to greater generalisation of treatment. In the current study a metacognitive technique, using visual imagery, was employed under conditions of rote repetition and spaced retrieval. Treatment was provided in an AB-BA crossover design with A as the active treatment and B as a no-treatment attention control to 20 individuals with brain injury. A group of 20 healthy participants served to control for effects of re-testing. Individuals with brain injury demonstrated improvement on the main outcome measure of prospective memory, the Memory for Intentions Screening Test, only after the active treatment condition. In addition, some generalisation of treatment was measured in daily life. Moreover, treatment gains were maintained for one year after treatment was completed.

Preliminary study of a rehabilitation program based on attentional processes to treat auditory hallucinations

INTRODUCTION

Despite the effectiveness of pharmacological treatment, residual hallucinations do not completely resolve in some medicated patients. The aim of this study was to investigate the efficacy of attention training for reducing hallucinations in individuals with psychosis.

METHODS

A randomised controlled trial was performed in which 20 individuals suffering auditory hallucinations received auditory stimulation similar to their internal voices, which was integrated into the RehaCom program of attention training. An equal number of individuals suffering auditory hallucinations did not receive this training. Cognitive and symptomatological variables were evaluated before and after the intervention period in both groups.

RESULTS

Only data of 16 subjects were analysed. Auditory hallucinations no longer occurred by the end of the training program in five of eight individuals, whereas their frequency, intensity and negative content and associated anxiety were significantly reduced in the remaining three. No changes in hallucinations were observed in the control group. Attentional processes and executive functions were significantly better in patients who underwent the training than in those who did not at the end of the intervention period.

CONCLUSIONS

Attention training can help people with auditory hallucinations develop an ability to ignore them, which can reduce or eliminate them entirely.

Prospective memory in schizophrenia and schizotypy

INTRODUCTION

Most evidence suggests that schizophrenia is associated with pervasive prospective memory (PM) impairment that does not vary as a function of task demands. However, a central tenet of the Multiprocess Framework is that PM involves both automatic and strategic processes, and that their relative prominence varies as a function of PM task characteristics, such as target-cue saliency.

METHODS

Participants with schizophrenia (n = 30), matched controls (n = 29), low schizotypes (n = 35), and high schizotypes (n = 36) were administered a PM measure in which saliency was manipulated. To further clarify the relationship between PM and schizotypy, high and low schizotypies were additionally assessed on Virtual Week, a laboratory measure which has documented sensitivity to schizophrenia-related impairment.

RESULTS

Relative to controls, participants with schizophrenia exhibited PM difficulties, but the magnitude of this deficit did not vary as a function of target-cue saliency. High and low schizotypes did not differ on any PM test parameter.

CONCLUSIONS

These data are consistent with other evidence showing that schizophrenia is characterised by generalised PM impairment. However, the absence of any schizotypy effects on PM does not support the recent suggestion that PM may represent an endophenotype for schizophrenia.

Prospective Memory Intervention: A Review and Evaluation of a Pilot Restorative Intervention

Prospective memory impairments continue to be among the greatest impediments to return to work for individuals following neurological illness or injury. Current approaches to prospective memory intervention are reviewed in this article. These include behavioral interventions, metacognitive strategies and restorative approaches. In addition, the summary of a study using the restorative approach is presented and discussed. Eight subjects were given a course of prospective memory training designed to increase the length of time that they are able to maintain to-be-performed tasks in mind. These subjects demonstrated improvement on neurospsychological measures, a standardised measure of prospective memory and a generalisation measure of prospective memory in daily life. These data lend support to the notion that prospective memory may be one area of cognition that is responsive to restorative intervention approaches.

A Review of Virtual Week for Prospective Memory Assessment: Clinical Implications

It is now recognised that prospective memory (PM) failures are commonly observed in clinical groups, and have important implications for functional independence. However, well-validated measures of PM have traditionally been lacking, making this construct difficult to assess in clinical practice. Rendell and Craik's (2000) Virtual Week measure was developed as an indicator of PM, and has been shown to have good psychometric properties and be sensitive to the effects of normal and abnormal adult ageing, as well as various forms of pathology. In this article, an overview of Virtual Week's characteristics is presented, and the literature relating to use of this measure in various populations reviewed. The potential implications of the development of a new computerised version of Virtual Week for clinical practice are discussed.

Profile of cognitive problems in schizophrenia and implications for vocational functioning

AIM

This literature review attempts to profile specific areas of cognition that have shown unique and consistent evidence of dysfunction among people with schizophrenia. In addition, their impact on vocational functioning is illustrated, so as to highlight the importance of managing these cognitive difficulties in vocational rehabilitation.

METHODS

Literature search was carried out on seven key cognitive domains identified by the National Institute of Mental Health in the USA. Their impact on vocational function was also reviewed.

RESULTS

It is found that attention, declarative and working memory, reasoning, problem-solving and social cognition are areas of impairment that have great impact on vocational functioning. Attention and memory problems affect learning of new work tasks. Executive function is particularly crucial in determining supported and open employment outcomes, as executive dysfunction cannot be easily compensated. Lastly, social cognition plays a major role in determining the success of workplace social exchanges.

CONCLUSION

Occupational therapists need to have a good understanding of the profile of cognitive problems among people with schizophrenia, in order to tailor our intervention according to their cognitive strengths and difficulties. Several cognitive remediation strategies and programs have been designed specifically for people with mental illness. Equipping ourselves with skills in conducting such programs will augment our expertise in vocational rehabilitation.

Incidental Encoding Strategies Did Not Improve Contextual Memory in Parkinson’s Disease Patients

Background. This study investigated the performance of patients with idiopathic Parkinson’s disease (PD) without dementia for incidental recognition memory and the effect of encoding strategies on contextual memory. Methods. The authors studied 21 patients with PD (ages 60-85, 12 women; Hoehn and Yahr I-III, Activities of Daily Living 70%-100%) and 22 healthy controls (ages 60-84, 18 women). Participants completed the vocabulary subtest of the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test (WCST). To assess the incidental recognition memory for item (object) and context (location of the object), participants of each group were assigned to 1 of 2 encoding conditions: ( a) an incidental associative instruction to bind the object to its location or ( b) a nonassociative, nonspecific instruction. Results. PD patients showed performance comparable to the control group’s on the vocabulary subtest and WCST. In contrast to controls, PD patients were unable to take advantage of the associative encoding instruction, which also had a deleterious effect on item recognition. Conclusion. This sample of participants with PD showed diminished item and context recognition memory and an impaired ability to use incidental memory encoding strategy, suggesting a compromised cognitive reserve. The fact that these alterations occurred in early stages of PD, and prior to more general cognitive alterations such as executive dysfunction, should be considered in the management of patients by using specific cognitive rehabilitation interventions.

Global impairment of prospective memory following acute alcohol

RATIONALE

Whilst the deleterious effects of alcohol on retrospective remembering have been widely documented, no study has yet objectively determined alcohol's effects on prospective memory (PM)--remembering to do something in the future.

OBJECTIVES

With this aim, the present study determined the acute effects of alcohol upon PM using a laboratory measure that simulates the PM tasks in everyday life--'Virtual Week'--both (a) in its standard form with regular, irregular, event-based and time-based PM tasks; and (b) an adapted version which enabled exploration of how future event simulation at encoding impacted upon subsequent PM.

METHODS

Forty healthy volunteers were administered 0.6 g/kg ethanol or a matched placebo in a double-blind fashion and completed the two versions of Virtual Week along with prose recall (to tap retrospective memory) and an executive function task.

RESULTS

Alcohol acutely produced global impairments across all (regular, irregular, event-based and time-based) PM tasks. It also produced impairments of episodic memory which positively correlated with PM performance of irregular tasks. Future-event simulation tended to enhance PM in the placebo but not in the alcohol group.

CONCLUSIONS

These findings on an objective measure of PM suggest that 4-5 units of alcohol will compromise PM abilities in everyday life.

Neuropsychological substrates and everyday functioning implications of prospective memory impairment in schizophrenia

Individuals with schizophrenia demonstrate impairment in prospective memory (ProM), which describes the multifaceted ability to execute a future intention. Despite its clear implications for everyday functioning, the neuropsychological substrates and functional correlates of ProM impairment in schizophrenia remain poorly understood. In this study, the Memory for Intentions Screening Test (MIST), a standardized measure of ProM, was administered to 72 outpatients with schizophrenia or schizoaffective disorder as part of a comprehensive neuropsychological and psychiatric research evaluation. Results showed that ProM was positively correlated with standard clinical tests of attention, working memory, processing speed, learning, and executive functioning, but not delayed recall. In the context of multiple neuropsychological predictors, learning ability was the only domain that independently contributed to ProM. Importantly, better ProM was predictive of higher functional capacity (as measured by the UCSD Performance-Based Skills Assessment-Brief Version), above and beyond the variability explained by demographic and disease factors. Analysis of component processes revealed that event-based ProM, as well as no response (i.e., omission) and task substitution errors were the strongest predictors of everyday functioning. Overall, these findings suggest that ProM impairment in schizophrenia is associated with multiple cognitive substrates, particularly episodic learning deficits, and plays an important role in everyday living skills. Studies regarding the potential effectiveness of ProM-based remediation strategies to improve functional outcomes in schizophrenia are indicated.

Prospective memory in schizophrenia: further clarification of nature of impairment

Prospective memory (PM) refers to the ability to execute a delayed intention and is different from retrospective memory (RM) in its nature and underlying mechanism (e.g., intention formation, maintenance, detection of PM cue and intention execution). Although preliminary studies have found PM impairment in patients with schizophrenia, the nature and magnitude of this problem in this clinical group is not yet fully known. The current study aimed to further clarify the nature of this impairment in schizophrenia. Fifty-four patients with schizophrenia and fifty-four healthy volunteers matched on demographic variables, IQ and executive functions took part in the study. Time-, event-, and activity-based PM tasks and a set of neurocognitive tests were administered to the participants. Results showed that patients with schizophrenia performed significantly worse on all sub-types of PM tasks, even after controlling for neurocognitive functions such as working memory, verbal memory, visual memory, and executive function. These findings suggest PM deficit is a primary deficit rather than a secondary consequence of neurocognitive impairments in schizophrenia. Analysis found that PM deficits may be mainly due to the impairment of the cue detection and intention retrieval stage.

Objective measures of prospective memory do not correlate with subjective complaints in schizophrenia

While a number of studies have shown that individuals with schizophrenia are impaired on various types of prospective memory, few studies have examined the relationship between subjective and objective measures of this construct in this clinical group. The purpose of the current study was to explore the relationship between computer-based prospective memory tasks and the corresponding subjective complaints in patients with schizophrenia, individuals with schizotypal personality features, and healthy volunteers. The findings showed that patients with schizophrenia demonstrated significantly poorer performance in all domains of memory function except visual memory than individuals with schizotypal personality disorder and healthy controls. More importantly, there was a significant interaction effect of prospective memory type and group. Although patients with schizophrenia were found to show significantly poorer performance on computer-based measures of prospective memory than controls, their level of subjective complaint was not found to be significantly higher. While subjective complaints of prospective memory were found to associate significantly with self-reported executive dysfunctions, significant relationships were not found between these complaints and performance on a computer-based task of prospective memory and other objective measures of memory. Taken together, these findings suggest that subjective and objective measures of prospective memory are two distinct domains that might need to be assessed and addressed separately.

HIV-associated prospective memory impairment increases risk of dependence in everyday functioning

HIV infection is associated with impairments in prospective memory (ProM), an aspect of episodic memory that refers to the ability to execute a future intention, such as remembering to take a medication at a specific time. The current study sought to examine the relationship between HIV-associated ProM impairment and the successful management of instrumental activities of daily living (IADLs). In a cohort of 66 HIV-infected individuals, ProM accounted for a significant proportion of variance in self-reported IADL dependence, over and above that which was explained by retrospective memory and by current affective distress. Analysis of component cognitive processes revealed that the relationship between HIV-associated ProM deficits and IADL dependence was driven by impaired cue detection and by deficits in self-initiated intention retrieval. Results were not better explained by demographic factors, HIV disease severity, psychiatric comorbidity, or substance use. Collectively, these data support the potential incremental ecological validity of ProM as a predictor of dependence in IADLs among persons living with HIV infection.

Prospective memory in schizophrenia: primary or secondary impairment?

Although a number of studies have now shown that schizophrenia is associated with impaired memory for future intentions (prospective memory), the degree and nature of the impairment remains to be clarified, as does the degree to which this impairment is secondary to deficits in other aspects of cognition. In the present study thirty participants with schizophrenia were compared with demographically matched controls on Virtual Week, a measure that closely represents the types of prospective memory tasks that actually occur in everyday life, and provides an opportunity to investigate the different sorts of prospective memory failures that occur. Participants with schizophrenia were significantly and comparably impaired on Virtual Week, irrespective of the specific prospective memory task demands. Importantly, after controlling for general cognitive functioning, executive functioning and retrospective memory, although the absolute magnitude of the deficit was reduced, significant impairment remained. These results suggest that individuals with schizophrenia experience generalized difficulties with prospective memory, and that whilst other cognitive deficits contribute to these difficulties, there is something unique to prospective remembering that is additionally disrupted in schizophrenia.

Deficits in cue detection and intention retrieval underlie prospective memory impairment in schizophrenia

Emerging evidence indicates that individuals with schizophrenia (SCZ) may exhibit deficits in prospective memory (ProM), a dissociable and ecologically important aspect of episodic memory entailing the formation, maintenance, and execution of future intentions. The present study aimed to elucidate the component processes of ProM impairment in 41 individuals with SCZ relative to 41 demographically similar healthy comparison (HC) participants. Results revealed that the SCZ group performed worse than HCs on overall ProM, with comparable deficits on time- and event-based ProM trials. In the SCZ cohort, better ProM performance was associated with younger age and less severe negative symptoms. Although a significantly greater number of Task Substitution and Loss of Time errors were evident in the SCZ group as compared to HCs, the most prevalent error type in SCZ was characterized by a complete failure to respond to the ProM cue. Importantly, the SCZ and HC groups did not differ on a post-test multiple-choice recognition trial, suggesting adequate formation and maintenance (i.e., retention) of the ProM cue-intention pairing when self-directed monitoring and retrieval demands were minimized. Findings indicate that SCZ is associated with impairment in the cue detection and self-initiated retrieval components of executing future intentions, which is consistent with a possible prefrontostriatal loop neuropathogenesis. Further studies are needed to explore the neurobiological mechanisms of SCZ-associated ProM impairment and the impact of such deficits on daily functioning (e.g., medication compliance).

Cognitive rehabilitation for schizophrenia and the putative role of motivation and expectancies

Cognitive rehabilitation (CR) approaches seek to enhance cognitive processes or to circumvent cognitive impairments in schizophrenia in an effort to improve functional outcome. In this review we examine the research findings on the 8 evidence-based approaches to cognitive remediation listed in the 2005 Training Grid Outlining Best Practices for Recovery and Improved Outcomes for People With Serious Mental Illness, developed by the American Psychological Association Committee for the Advancement of Professional Practice. Though the approaches vary widely in theoretical orientation and methods of intervention, the results are, for the most part, encouraging. Improvements in attention, memory, and executive functioning have been reported. However, many persons with schizophrenia are more impaired in real-world functioning than one would expect given the magnitude of their cognitive deficits. We may need to look beyond cognition to other targets such as motivation to identify the reasons that many persons with schizophrenia demonstrate such marked levels of disability. Although a number of current CR approaches address motivation to varying degrees, treating motivation as a primary target may be needed to maximize CR outcomes.

Effects of a neuropsychological rehabilitation programme on schizophrenic patients' subjective perception of improvement

Cognitive and neuropsychological deficits have long been recognised as part of the schizophrenic syndrome. As these deficits persist after acute psychosis subsides and contribute to the social and occupational difficulties often experienced by individuals with schizophrenia, researchers have begun to consider the applicability of neuropsychological rehabilitation techniques to the treatment of schizophrenic neuropsychological deficits. Although the effectiveness of cognitive rehabilitation programmes in schizophrenia has been addressed, no attention has been afforded to whether the trained patient perceives improvement of the cognitive processes instructed. The present study utilised a treatment versus control group comparison design to evaluate the effect of a neuropsychological rehabilitation programme on the perception of improvement both in schizophrenic patients and their therapists. Twenty-four participants diagnosed with schizophrenia participated in the study. One half of the sample was trained by means of Attention Process Training (APT) and the rest of the patients comprised the control group. No significant differences in perception of improvement were found between treatment and control group, and trained patients found the APT more useful than did their therapists.

[Cognitive rehabilitation of schizophrenia: a pragmatic approach of the integration process to battle against refractory symptoms]

Classical approaches of treatment of people with schizophrenia recognize that successful treatment of this illness requires more than simply reducing the frequency, intensity and duration of positive symptoms such as hallucinations. In fact, a more comprehensive approach aimed at reducing disability is indicated in most cases. It has recently been proposed that new approaches to the cognitive rehabilitation of schizophrenia need to recognize the importance of 1) systematically addressing motivation, self-esteem, and affective factors when designing cognition enhancing interventions ; 2) the need to move beyond one-size-fits-all interventions and develop individual-specific treatments ; and 3) the need to address abnormalities in the experience of the self when designing interventions to optimize cognitive and behavioural performance. The case study presented here is an example of a cognitive rehabilitation approach of schizophrenia that attempts to promote the self integration process by means of a range of specific interventions and addresses three issues noted above. Preliminary results suggest that it could be very beneficial for patients suffering of schizophrenia.

The Status of Empirical Support for Treatments of Attention Deficits

Deficits in attention and self-regulation are common complaints associated with a number of disorders across the lifespan. The need to address attentional deficits is based on the premise that attention is a precursor and prerequisite to information processing and related cognitive tasks as well as a key factor in the success of other rehabilitation efforts. Many treatment programs have been developed with the intention of restoring or rehabilitating the impaired components of attention; the number and variety of attention programs is increasing rapidly. The purpose of this article is to evaluate available empirical support regarding the efficacy of treatments for remediation of attention deficits across disorders and age levels. The search of the major databases yielded 83 studies that included treatment of attentional deficits. Empirical studies were reviewed and categorized by the type of trial, whether or not the study included a control group, and the nature of the control group. The methodology and results of each study were then rated. For each treatment identified, the aggregated studies were then considered by the disorder of the samples included in the studies. Results indicated that, regardless of the treatment program or population, the existing research does not provide sufficient evidence to reach any conclusions about the efficacy of programs designed to address attention deficits. Before any conclusions, positive or negative, can be drawn, there is a need for more rigorous study of available treatment programs across age levels and disorders, with sufficient baseline and outcome data as well as control or alternative treatment conditions.