Peter G. Rendell

A review of the impact of pregnancy on memory function

Although until recently much of the evidence for pregnancy-related deficits in memory was anecdotal or based on self-report, a number of studies have now been conducted that have tested whether these subjective appraisals of memory difficulties reflect objective impairment. However, these studies have failed to yield consistent results. A meta-analysis of the 14 studies that have been conducted over the past 17 years comparing pregnant and/or postpartum women with healthy matched controls on behavioral measures of memory was conducted. The results indicate that pregnant women are significantly impaired on some, but not all, measures of memory, and, specifically, memory measures that place relatively high demands on executive cognitive control may be selectively disrupted. The same specific deficits associated with pregnancy are also observed postpartum. These findings highlight the need for exploration of the etiologies and functional consequences of pregnancy-related memory difficulties and may help to guide the interpretation of neuropsychological data for the purpose of determining cognitive status in individuals who are pregnant or postpartum.

Empathy, social functioning and schizotypy.

Whilst affective empathy is concerned with ones emotional response to the affective state of another, cognitive empathy refers to ones understanding of anothers mental state, and deficits in both are believed to contribute to the social behavioral abnormalities associated with schizophrenia. The present study aimed to test whether individual differences in normally distributed schizotypal personality traits are related to cognitive and affective empathy, and whether any observed association between schizotypy and empathy mediates the relationship between schizotypy and (reduced) social functioning. Non-clinical volunteers (N=223) completed measures of schizotypal personality, cognitive and affective empathy, social functioning and negative affect. The results indicated that higher schizotypy was associated with reduced empathy, poorer social functioning and increased negative affect. Of the specific schizotypal dimensions (positive, negative and disorganized), only negative schizotypy was significantly associated with social functioning, and this relationship persisted even after controlling for negative affect. Further, affective empathy functioned as a partial mediator in this relationship. These data show that the relationship between negative schizotypy and social functioning is at least partially attributable to deficits in affective empathy.

Emotion regulation in schizophrenia: Affective, social and clinical correlates of suppression and reappraisal

Individuals can exert considerable control over their experience and expression of emotion by applying different regulatory strategies such as reappraisal and suppression. However, although it has been suggested that blunted affect in schizophrenia, characterized by markedly reduced emotion expressivity alongside apparently normal emotion experience, may reflect overuse of suppression, no study to date has assessed self-reported use of these different emotion regulatory strategies in relation to this disorder. In the present study, 41 individuals with schizophrenia and 38 control participants completed a self-report measure that differentiated between use of suppression and reappraisal. Symptom severity and various aspects of cognitive and psychosocial functioning were also assessed. Relative to controls, individuals with schizophrenia did not differ with regard to their reported use of suppression and reappraisal, and reported use of both strategies was unrelated to clinical ratings of blunted affect. However, whereas (lower) use of reappraisal was associated with greater social function impairment for both groups, only for controls was (greater) use of suppression associated with reduced social functioning. Implications for understanding blunted affect and social dysfunction in schizophrenia are discussed.

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.

Age and Individual Differences in Prospective Memory during a “Virtual Week”: The Roles of Working Memory, Vigilance, Task Regularity, and Cue Focality

Young (ages 18-22 years) and older (ages 61-87 years) adults (N = 106) played the Virtual Week board game, which involves simulating common prospective memory (PM) tasks of everyday life (e.g., taking medication), and performed working memory (WM) and vigilance tasks. The Virtual Week game includes regular (repeated) and irregular (nonrepeated) PM tasks with cues that are either more or less focal to other ongoing activities. Age differences in PM were reduced for repeated tasks, and performance improved over the course of the week, suggesting retrieval was more spontaneous or habitual. Correlations with WM within each age group were reduced for PM tasks that had more regular or focal cues. WM (but not vigilance) ability was a strong predictor of irregular PM tasks with less focal cues. Taken together, these results support the hypothesis that habitual and focally cued PM tasks are less demanding of attentional resources (specifically, WM), whereas tasks that are more demanding of controlled attentional processes produce larger age differences, which may be attributable to individual differences in WM.

Evidence for deficits in facial affect recognition and theory of mind in multiple sclerosis

Multiple sclerosis (MS) is a white matter disease associated with neurocognitive difficulties. More recently the potential for white matter pathology to also disrupt important aspects of emotion understanding has been recognized. However, no study to date has assessed whether capacity for facial affect recognition and theory of mind (ToM) is disrupted in MS, or whether any observed deficits are related to more general cognitive impairment. In the present study MS participants (n = 27) and nonclinical controls (n = 30) were administered measures of facial affect recognition, ToM, and cognitive functioning. MS participants were significantly impaired on the ToM task, and also presented with specific deficits decoding facial emotions of anger and fear. Performance on the measures of facial affect recognition and ToM were related to general cognitive functioning, and in particular, measures sensitive to executive dysfunction and information processing speed. These data highlight the need for future research to more fully delineate the extent and implications of emotion understanding difficulties in this population.

Recognition of disgust is selectively preserved in Alzheimer's disease

The neural substrates that subserve decoding of different emotional expressions are subject to different rates of degeneration and atrophy in Alzheimers disease (AD), and there is therefore reason to anticipate that a differentiated profile of affect recognition impairment may emerge. However, it remains unclear whether AD differentially affects the recognition of specific emotions. Further, there is only limited research focused on whether affect recognition deficits in AD generalize to more ecologically valid stimuli. In the present study, relatively mild AD participants (n=24), older controls (n=30) and younger controls (n=30) were administered measures of affect recognition. Significant AD deficits were observed relative to both the younger and older control groups on a measure that involved labeling of static images of facial affect. AD deficits on this measure were observed in relation to all emotions assessed (anger, sadness, happiness, surprise and fear), with the exception of disgust, which was preserved even relative to the younger adult group. The relative preservation of disgust could not be attributed to biases in the choice of labels made, and it is suggested instead that this finding might reflect the relative sparing of the basal ganglia in AD. No significant AD effect was observed for the more ecologically valid measure that involved dynamic displays of facial expressions, in conjunction with paralinguistic and body movement cues, although a trend for greater AD difficulty was observed.

Age-Related Effects in Prospective Memory are Modulated by Ongoing Task Complexity and Relation to Target Cue

ABSTRACT Two experiments examined the puzzling variation in the age-related patterns for event-based prospective memory tasks. Both experiments involved a famous faces ongoing task with a feature of the famous face as the target for the prospective memory task. In Experiment 1, a substantial age deficit was found on the prospective memory task when the cue was nonfocal (wearing glasses) to the ongoing task, replicating previous research, but this deficit was significantly reduced with a focal cue (first name John). In Experiment 2, the prospective memory cue (wearing glasses) was held constant and the demands of the ongoing task of naming faces were varied. The substantial age differences found with a nonfocal cue were eliminated when the ongoing task was made less challenging. The findings help reconcile the divergent age-related findings reported in the literature.

Prospective memory impairment in ‘ecstasy’ (MDMA) users

RationaleConsiderable research indicates that “ecstasy” users perceive their memory for future intentions (prospective memory) to be impaired. However, only one empirical study to date has directly tested how this capacity is affected by ecstasy use, and this study provided relatively limited information regarding the extent, scope, or implications of problems experienced.ObjectivesThe present study assessed prospective performance on a laboratory measure of prospective memory 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 (“Virtual Week”).MethodEcstasy user group (27 current users and 34 nonusers) was between participants, and prospective memory task (regular, irregular, time-check) was within participants. A measure sensitive to specific aspects of psychopathology was also administered.ResultsEcstasy users were significantly impaired on Virtual Week, and these deficits were of a comparable magnitude irrespective of the specific prospective memory task demands. The pattern of results was unchanged after controlling for marijuana use, level of psychopathology, and sleep quality. Further, prospective memory was shown to be significantly impaired for both relatively infrequent and relatively frequent ecstasy users, although for the latter group the magnitude of this deficit was greater.ConclusionsProspective memory performance is sensitive to regular and even moderate ecstasy use. Importantly, ecstasy users experience generalized difficulties with prospective memory, suggesting that these deficits are likely to have important implications for day-to-day functioning.

Prospective memory function in mild cognitive impairment and early dementia

When compared with controls, both mild cognitive impairment (MCI) and dementia are each associated with impaired memory for future intentions, or prospective memory (PM). However, prior studies have failed to agree on whether there are group differences in PM function between those with MCI and dementia. Furthermore, 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, MCI (n = 48), dementia (n = 39), and control participants (n = 53) were compared on Virtual Week, a measure that closely represents the types of PM tasks that occur in everyday life. Both clinical groups exhibited impairment irrespective of the specific task demands, but the magnitude of this deficit was greater for those with dementia. After covarying for other key cognitive parameters, although the absolute magnitude of the deficit was reduced, significant impairment remained. These results indicate that individuals with MCI, and to a greater extent dementia, experience generalized difficulties with PM. It is suggested that, while other cognitive deficits contribute to these difficulties, there is something unique to prospective remembering that may be additionally disrupted in these groups.