Increased spreading activation in depression

Schizophrenia patients perform as well as healthy controls on creative problem solving when fluid intelligence is accounted for

INTRODUCTION

This study examined creative problem solving in schizophrenia. We aimed to verify three hypotheses: (H1) schizophrenia patients differ from healthy controls in the accuracy of creative problem solving; (H2) schizophrenia patients are less effective at evaluating and rejecting incorrect associations and (H3) have a more idiosyncratic way of searching for semantic associations compared to controls.

METHODS

Six Remote Associates Test (RAT) items and three insight problems were applied to schizophrenia patients and healthy controls. We compared groups on the overall accuracy in the tasks to verify H1 and developed a novel method of comparing the patterns of errors in the RAT to verify H2 and H3. We controlled for fluid intelligence to eliminate this significant source of variation, as typically creativity and intelligence are significantly related.

RESULTS

Bayesian factor analysis did not support the group differences in either insight problems and RAT accuracy or the patterns of RAT errors.

CONCLUSIONS

The patients performed as well as the controls on both tasks. Analysis of RAT errors suggested that the process of searching for remote associations is comparable in both groups. It is highly improbable that individuals with schizophrenia benefit from their diagnosis during creative problem solving.

What Drives False Memories in Psychopathology? A Case for Associative Activation

In clinical and court settings, it is imperative to know whether posttraumatic stress disorder (PTSD) and depression may make people susceptible to false memories. We conducted a review of the literature on false memory effects in participants with PTSD, a history of trauma, or depression. When emotional associative material was presented to these groups, their levels of false memory were raised relative to those in relevant comparison groups. This difference did not consistently emerge when neutral or nonassociative material was presented. Our conclusion is supported by a quantitative comparison of effect sizes between studies using emotional associative or neutral, nonassociative material. Our review suggests that individuals with PTSD, a history of trauma, or depression are at risk for producing false memories when they are exposed to information that is related to their knowledge base.

Creativity and Mood Disorder: A Systematic Review and Meta-Analysis

Although the belief that creativity is related to psychopathology is prevalent, empirical evidence is limited. Research findings relating to mood disorder in particular are mixed, possibly as a result of differing research approaches (e.g., assessing the creativity of individuals with versus without mood disorder opposed to the prevalence of mood disorder in creative versus noncreative individuals). Therefore, a systematic review and meta-analysis were conducted to investigate prior research examining the link between mood disorder and creativity from three distinct research approaches. Multilevel random effects models were used to calculate the overall effect size for studies that assessed (a) creativity in a clinical versus nonclinical sample ( k = 13), (b) mood disorder in a creative versus noncreative sample ( k = 10), and (c) the correlation between dimensional measures of creativity and mood disorder symptoms ( k = 15). Potential moderators were examined using meta-regression and subgroup analyses, as significant heterogeneity was detected among the effects in all three analyses. Results reveal a differential strength and pattern of effects across the three analyses, suggesting that the relationship between creativity and mood disorder differs according to the research approach. The theoretical implications of results and potential mechanisms responsible for the relationship between creativity and mood disorder are discussed.

Spreading activation in nonverbal memory networks

Theories of spreading activation primarily involve semantic memory networks. However, the existence of separate verbal and visuospatial memory networks suggests that spreading activation may also occur in visuospatial memory networks. The purpose of the present investigation was to explore this possibility. Specifically, this study sought to create and describe the design frequency corpus and to determine whether this measure of visuospatial spreading activation was related to right hemisphere functioning and spreading activation in verbal memory networks. We used word frequencies taken from the Controlled Oral Word Association Test and design frequencies taken from the Ruff Figural Fluency Test as measures of verbal and visuospatial spreading activation, respectively. Average word and design frequencies were then correlated with measures of left and right cerebral functioning. The results indicated that a significant relationship exists between performance on a test of right posterior functioning (Block Design) and design frequency. A significant negative relationship also exists between spreading activation in semantic memory networks and design frequency. Based on our findings, the hypotheses were supported. Further research will need to be conducted to examine whether spreading activation exists in visuospatial memory networks as well as the parameters that might modulate this spreading activation, such as the influence of neurotransmitters.

Differential lexical and semantic spreading activation in Alzheimer's disease

Alzheimer's disease (AD) is known to be associated with disruption in semantic networks. Previous studies examining changes in spreading activation in AD have used a lexical decision task paradigm. We have used a paradigm based on average word frequencies obtained from the words generated on the Controlled Oral Word Association Test (COWAT) and the Animal Naming (AN) test. The COWAT and AN tests were administered to a group of 25 patients with AD and 20 control participants. We predicted that the patients with AD would have higher average word frequencies on the COWAT and AN tests than the control participants. The results indicated that the AD group generated words with a higher average word frequency on the AN test but a lower average word frequency on the COWAT. The reasons for the discrepancy in average word frequencies on the AN test and COWAT are discussed.