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.

LH-Independent Testosterone Secretion Is Mediated by the Interaction Between GNRH2 and Its Receptor Within Porcine Testes.

Unlike classic gonadotropin-releasing hormone 1 (GNRH1), the second mammalian isoform (GNRH2) is an ineffective stimulant of gonadotropin release. Species that produce GNRH2 may not maintain a functional GNRH2 receptor (GNRHR2) due to coding errors. A full-length GNRHR2 gene has been identified in swine, but its role in reproduction requires further elucidation. Our objective was to examine the role of GNRH2 and GNRHR2 in testicular function of boars. We discovered that GNRH2 levels were higher in the testis than in the anterior pituitary gland or hypothalamus, corresponding to greater GNRHR2 abundance in the testis versus the anterior pituitary gland. Moreover, GNRH2 immunostaining was most prevalent within seminiferous tubules, whereas GNRHR2 was detected in high abundance on Leydig cells. GNRH2 pretreatment of testis explant cultures elicited testosterone secretion similar to that of human chorionic gonadotropin stimulation. Treatment of mature boars with GNRH2 elevated testosterone levels similar to those of GNRH1-treated males, despite minimal GNRH2-induced release of luteinizing hormone (LH). When pretreated with a GNRHR1 antagonist (SB-75), subsequent GNRH2 treatment stimulated low levels of testosterone secretion despite a pattern of LH release similar to that in the previous trial, suggesting that SB-75 inhibited testicular GNRHR2s. Given that pigs lack testicular GNRHR1, these data may indicate that GNRH2 and its receptor are involved in autocrine or paracrine regulation of testosterone secretion. Notably, our data are the first to suggest a biological function of a novel GNRH2-GNRHR2 system in the testes of swine.

Remembering to remember: prospective memory in children with epilepsy.

Prospective memory, the ability to remember to perform an intended act in the future, is a complex process that involves several stages and cognitive domains. This study sought to investigate prospective memory functioning in children with idiopathic epilepsy using tasks from the Rivermead Behavioral Memory Test for Children (RBMT-C) and the Memory for Intentions Screening Test for Youth (MISTY). Performances on prospective memory task characteristics of the MISTY (i.e., cue-type, length of time delay, and response type) were also compared between and across participant groups. Healthy children (N = 26) were found to have higher overall IQ and verbal IQ scores when compared to children with epilepsy (N = 19). Group differences in prospective memory functioning were found in subtests of the RBMT-C but not on the MISTY. Lastly, while there was no significant interaction effect between the groups and MISTY task characteristics, main effects were found across participant groups; all participants performed better on event-based tasks when compared to time-based tasks and on two-minute when compared to 10-minute time delays. Overall, findings suggest potential differences in cognitive functioning, particularly in IQ and prospective memory, in children with idiopathic epilepsy, though due to differences in findings across prospective memory tasks, further research is warranted to more definitively ascertain the extent, if any, of prospective memory deficits in children with epilepsy.

Assessing prospective memory in children using the Memory for Intentions Screening Test for Youth (MISTY).

OBJECTIVE: Prospective memory (PM) is defined as the ability to remember to complete an intention in the future. The first aim of this study was to address the need for clinically useful measures of PM in children, by assessing the psychometric properties of a new measure of PM in children and adolescents, the Memory for Intentions Screening Test for Youth (MISTY). The second aim was to assess the relationship between prospective memory and age, particularly the relationships between age and the impact of different PM task demands. The third aim was to examine children's performance on different aspects of PM, such as time-based versus event-based cues. METHOD: One-hundred twenty-four children between the ages of 4 and 15 were given the MISTY. RESULTS: Analyses revealed good internal consistency among the eight individual MISTY trials and among the six MISTY subscales which included two different cue types (event-based and time-based), two different time delays (2 minutes and 10 minutes), and two different response types (action and verbal). Results also revealed good split-half and inter-rater reliability. Findings highlighted significant correlations between age and the MISTY total score and all subscales, consistent with PM lifespan research. On the MISTY, children overall performed better on event-based cues than on time-based cues, and on shorter time delays than longer ones; there was no effect of response type (i.e. action vs. verbal response). CONCLUSIONS: The MISTY is a promising instrument with sound psychometric properties that could be useful in both clinical and research settings. Additionally, this study highlights the age-related process of PM development in children.

A comparison of laboratory, clinical, and self-report measures of prospective memory in healthy adults and individuals with brain injury.

Individuals with traumatic brain injury (TBI) have demonstrated deficits in prospective memory (PM) functioning when compared to healthy adults. These deficits have been measured using laboratory measures, clinical measures, and self-report questionnaires. However, PM has been shown to involve multiple cognitive processes and have a variety of stages. Thus, it is not known whether these measures all assess the same aspects of PM. Thus, this study was designed to measure the convergent validity of the three types of PM measures in both healthy adults and individuals with TBI. We aimed to investigate the convergent validity of the three types of tasks in two ways. First, we sought to investigate whether the PM deficits experienced by people with TBI are consistent across tasks. Second, we sought to examine the relationship between the three types of tasks. Results demonstrated that while all three types of measures were sensitive to PM deficits in TBI, there were differences in the aspects/processes of PM being measured. Data from the laboratory measure suggested a specific difficulty with detecting the correct cue. Data from the clinical measure suggested that TBI has a greater effect on time-based cues than event-based cues and that the primary deficit is a prospective intention retrieval deficit rather than the retrospective memory component. In addition, those with TBI did not differ from healthy adults when the time delay was short enough, suggesting that PM is not universally impaired. Data from the self-report questionnaire suggested that those with TBI are more sensitive to difficulties with basic activities of daily living rather than instrumental activities on daily living. These results are discussed in terms of rehabilitation techniques that could focus first on cue detection and use basic activities of daily living as outcome measures.