Measuring subjective clustering of verbal information after moderate-severe traumatic brain injury: a preliminary study.

BACKGROUND: There is no agreed upon measure of subjective clustering for clinical use in patients following moderate-severe traumatic brain injury (TBI). OBJECTIVE: This study investigated whether measures of subjective clustering, subjective organization (SO) and adjusted ratio of clustering (ARC), were appropriate for use in patients following moderate-severe TBI. METHODS: Twenty participants with moderate-severe TBI in the chronic stage of recovery and 20 control participants recalled a list of unrelated words over six trials. The authors assessed if the SO and ARC measures could discriminate the groups' ability to subjectively cluster the words. The authors also examined whether the SO and ARC measures correlated with recall and learning rate, and if combining the measures improved the predictive accuracy. RESULTS: Participants with moderate-severe TBI performed significantly worse on the SO measure, but there were no group differences regarding the ARC measure. The SO measure positively correlated with recall, but not learning rate. The ARC measure did not positively correlate with recall or learning rate, and combining the measures did not enhance the predictive accuracy. CONCLUSIONS: The SO measure is likely an appropriate candidate for clinical use. However, there are problems with the ARC measure that limit its use as a clinical tool.

Cognitive differences between adults with traumatic brain injury and specific learning disorder.

Background: Impaired working memory, attention, and processing speed are common in individuals with traumatic brain injury (TBI) and specific learning disorder (SLD). Yet, there is a paucity of research that has examined cognitive differences between these groups.Objective: The current study examined potential group differences between individuals with TBI and SLD on performance-based tests of working memory, attention, and processing speed. Subsequently, the study examined whether just processing speed tests could discriminate persons with TBI versus SLD.Method: The authors analyzed archival data to assess differences between 39 adult participants with moderate-severe TBI versus 57 adult participants with SLD on the Trail Making Test Part A, Trail Making Test Part B, Digit Span test, and Symbol Search test.Results: 95% confidence intervals revealed that participants with TBI performed significantly worse on the Trail Making Test Part A and Symbol Search test. Logistic regression analysis procedures revealed that Trail Making Test Part A was the most sensitive discriminator.Conclusion: Diagnosis of moderate-severe TBI compared to SLD can be determined by poor performance on measures of visual scanning and processing speed. These findings may be used for diagnostic interpretation and treatment planning by clinicians.

Organization and recall of visual information after traumatic brain injury.

BACKGROUND: Subjective organization (SO) is the ability to structure information to help facilitate storage and retrieval. There is a paucity of research concerning how a person subjectively organizes visual information. OBJECTIVES: This study investigates whether traumatic brain injury (TBI) hinders the ability to subjectively organize and recall visual symbols. The authors use an Association Rule Modeling (ARM) procedure to measure SO and explore whether the complexity of the rules generated from the ARM predicted recall of symbols. METHOD: Twenty-two collegiate athletes with self-reported, repetitive, mild TBI and 22 college students without TBI participated. All participants completed a list learning task that assessed their free recall of unfamiliar symbols. ARM revealed the associative structure among the symbols in the list for each participant. RESULTS: Results showed that collegiate athletes with repetitive, mild TBI develop significantly fewer association rules for visual stimuli compared to college students without TBI. Furthermore, collegiate athletes with TBI produce fewer complex SO rules for the visual stimuli relative to college students without TBI. CONCLUSION: Brain injury diminishes a person's ability to subjectively organize novel visual information. ARM is a sensitive clinical measure of SO for patients with TBI.

Efficacy of memory rehabilitation therapy: a meta-analysis of TBI and stroke cognitive rehabilitation literature.

OBJECTIVE: To examine the efficacy of cognitive rehabilitation strategies specifically designed to improve memory after traumatic brain injury (TBI) and stroke vs. memory improvement with the passage of time. DESIGN AND METHODS: A meta-analysis was performed on 26 studies of memory retraining and recovery that were published between the years of 1985 and 2013. Effect sizes (ESs) from each study were calculated and converted to Pearson's r and then analysed to assess the overall effect size and the relationship among the ESs, patient demographics and treatment interventions. RESULTS: RESULTS indicated a significant average ES (r = 0.51) in the treatment intervention conditions, as well as a significant average ES (r = 0.31) in the control conditions, in which participants did not receive any treatment. The largest ESs occurred in studies of stroke patients and studies concerning working memory rehabilitation. CONCLUSIONS: RESULTS showed that memory rehabilitation was an effective therapeutic intervention, especially for stroke patients and for working memory as a treatment domain. However, the results also indicated that significant memory improvement occurred spontaneously over time.

Measuring subjective organization in monozygotic twins discordant for traumatic brain injury: A case report.

BACKGROUND: Subjective organization (SO) facilitates storage and retrieval of information but is often impaired following traumatic brain injury. No study has compared measures of SO using association rule analyses to clustering analyses. Moreover, there have been no studies investigating whether patients post-brain injury subjectively organize non-verbal information. OBJECTIVE: This study investigates the relationship between SO and recall of words and symbols with participants discordant for traumatic brain injury. Additionally, the authors explored the conditions under which clustering or association rule measures of SO were best used. METHOD: Two female monozygotic twins discordant for traumatic brain injury completed a multi-trial free recall test of words and symbols. The authors examined whether measures of SO derived from clustering analysis or association rule modeling could differentiate organizational abilities between participants' data. RESULTS: The twin following sequential traumatic brain injuries demonstrated significantly less SO and recall relative to the twin without a traumatic brain injury. Both twins subjectively organized verbal and non-verbal information and each measure could differentiate the twins' performance. CONCLUSION: The quantitative analysis of SO can provide clinicians with valuable information concerning a patient's recall performance. This study illustrates practical issues that may influence a clinician's choice of these techniques.

Using association rules to measure Subjective Organization after Acquired Brain Injury.

BACKGROUND: Subjective Organization (SO) refers to the human tendency to impose organization on our environment. Persons with Acquired Brain Injury (ABI) often lose the ability to organize however, there are no performance based measures of organization that can be used to document this disability. OBJECTIVE: The authors propose a method of association rule analysis (AR) that can be used as a clinical tool for assessing a patient's ability to organize. METHOD: Twenty three patients with ABI recalled a list of twelve unrelated nouns over twelve study and test trials. Several measures of AR computed on these data were correlated with various measures of short-term, long-term, and delayed recall of the words. RESULTS: All of the AR measures correlated significantly with the short-term and long-term memory measures. The confidence measure was the best predictor of memory and the number of association rules generated was the best predictor of learning. CONCLUSIONS: The confidence measure can be used as a clinical tool to assess SO with individual ABI survivors.

Experiences of stigma among outpatients with schizophrenia.

Many individuals with schizophrenia are devalued and discriminated against because of their mental illness. There has been only limited study of how individuals with schizophrenia experience mental illness stigma. We evaluated 74 stable outpatients with schizophrenia receiving community care. Study participants were interviewed with the Consumer Experiences of Stigma Questionnaire (CESQ), the Positive and Negative Syndrome Scale, and several social functioning measures. On the CESQ, all but one respondent indicated having at least one stigma experience. The most frequently reported CESQ items were respondents' worry about being viewed unfavorably because of their psychiatric illness (70%) and avoidance of telling others about it (58%). Many respondents also indicated having heard offensive statements (55%) and media accounts (43%) about persons with psychiatric disorders. Socioeconomic variables, but not symptoms or social functioning measures, were related to the extent of stigma and discrimination experiences. These results document the extent to which persons with mental illness experience negative reactions from others. Strategies are needed to enhance how persons with schizophrenia cope with stigma.