Modeling and estimating recall processing capacity: Sensitivity and diagnostic utility in application to mild cognitive impairment

We investigate the potential for using latency-based measures of retrieval processing capacity to assess changes in performance specific to individuals with mild cognitive impairment (MCI), a reliable precursor state to Alzheimer’s Disease. Use of these capacity measures is motivated in part by exploration of the effects of atrophy on a computational model of a basic hippocampal circuit. We use this model to suggest that capacity may be a more sensitive indicator of the underlying atrophy than speed of processing, and test this hypothesis by adapting a standard behavioral measure of memory (the free and cued selective reminding test, FCSRT) to allow for the collection of cued recall latencies. Participants were drawn from five groups: college-aged, middle-aged, healthy elderly, those with a diagnosis of MCI, and a sample of MCI control participants. The measure of capacity is shown to offer increased classificatory sensitivity relative to the standard behavioral measures, and is also shown to be the behavioral measure that correlated most strongly with hippocampal volume.     

How Much Distress Is Too Much on Deployed Operations? Validation of the Kessler Psychological Distress Scale (K10) for Application in Military Operational Settings

The aim of this study was threefold: (a) to assess the factor structure of the Kessler Psychological Distress Scale (K10) to determine whether interpreting the scale as a single dimensional measure of psychological distress is justified in military operational setting; (b) to validate the K10 for mental health surveillance in operational settings against self-reported occupational impairment; (c) to evaluate whether the K10 has better discriminatory power than de facto standards for mental health surveillance on deployment, namely the Patient Health Questionnaire and the Posttraumatic Stress Disorder Checklist, Civilian version. A convenience sample of Canadian Armed Forces personnel serving in Afghanistan (N = 1,264) completed self-report measures of psychological distress and occupational impairment. On examination of 6 competing models, the authors determined that interpreting the K10 as a measure of unspecified psychological distress is justified. Using receiver operating characteristic (ROC) curve analysis, they identified new cutoff values for dichotomous and polychotomous scoring methods. After comparing the area beneath the ROC curves for each of the 3 mental health surveillance questionnaires, the authors determined that all measures perform well as predictors of self-rated occupational impairment, with values ranging from .86 to .90. These results highlight the importance of cross-setting validation and demonstrate that validating psychological screening questionnaires against self-report measures of occupational impairment can be a useful strategy for understanding the manifestation of psychological distress on deployed military operations.     

The mathematical abilities of children with cochlear implants

Research has shown that cochlear implants give rise to improvements in speech recognition and production in children with profound hearing loss but very few studies have explored mathematical abilities in these children. The current study compared the mathematical abilities of 24 children with cochlear implants (mean age 10 years 1 month) to a control group of 22 hearing children (mean age 9 years 8 months). The math questions were categorized into questions that tapped into arithmetic or geometrical reasoning. It was predicted that the cochlear implant group would perform below the hearing group on the arithmetic questions but not the geometrical reasoning questions. Unexpectedly, the results showed that the cochlear implant group performed significantly below the hearing group on both types of math questions, but that this difference was mediated by language skill as assessed by vocabulary knowledge. The clinical implications of these results and possible future research results are considered.     

Recognition of Affective Speech Prosody and Facial Affect in Deaf Children with Unilateral Right Cochlear Implants

Cochlear implant (CI) devices provide the opportunity for children who are deaf to perceive sound by electrical stimulation of the auditory nerve, with the goal of optimizing oral communication. One part of oral communication concerns meaning, while another part concerns emotion: affective speech prosody, in the auditory domain, and facial affect, in the visual domain. It is not known whether childhood CI users can identify emotion in speech and faces, so we investigated speech prosody and facial affect in children who had been deaf from infancy and experienced CI users. METHOD: Study participants were 18 CI users (ages 7–13 years) who received right unilateral CIs and 18 age- and gender-matched controls. Emotion recognition in speech prosody and faces was measured by the Diagnostic Analysis of Nonverbal Accuracy. RESULTS: Compared to controls, children with right CIs could identify facial affect but not affective speech prosody. Age at test and time since CI activation were uncorrelated with overall outcome measures. CONCLUSION: Children with right CIs recognize emotion in faces but have limited perception of affective speech prosody.     

Short-Term Memory and Working Memory in Children with Blindness: Support for a Domain General or Domain Specific System?

The study explored the contribution of two component processes (phonological and executive) to blind children's memory performance. Children with blindness and sight were matched on gender, chronological age, and verbal intelligence and compared on measures of short-term memory (STM) and working memory (WM). Although the measures were highly correlated, the results from two experiments indicated that the blind children were superior to sighted children on measures of STM, but not on measures of WM. The results supported the notion that children with blindness have advantages on memory tasks that draw upon resources from the phonological loop. However, comparable performance between the ability groups on WM measures suggests there are domain specific aspects in the executive system.     

The role of verbal and nonverbal memory in the Family Pictures Subtest: Data from children with specific language impairment

This study examined the contribution of verbal and visual memory to performance on the Family Pictures subtest of the Children’s Memory Scale. This subtest purports to assess declarative memory functioning in the visual/nonverbal domain. A total of 115 nine-year-old children participated in this study. Fifty-eight had specific language impairment (SLI), whilst the remaining 57 were typically developing (TD), with no history of language difficulties. Results showed that the children with SLI, who had intact declarative memory for visual but not verbal information, obtained significantly lower scores on the Family Pictures subtest when compared to the TD group. Regression analyses revealed that across the entire sample, individual differences on the Family Pictures subtest was best predicted by a measure of verbal working memory. These results question whether the Family Pictures subtest can be considered a measure of visual memory in pediatric populations. These results have implications for the interpretation of scores on this subtest regarding the nature of the types of neurocognitive difficulties children may exhibit.     

Production and Identification Repetition Priming in AmnesticMild Cognitive Impairment

ABSTRACT

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

Health numeracy and cognitive decline in advanced age

ABSTRACT

The study aimed at investigating health numeracy in cognitively well performing healthy participants aged from 50 to 95 years as well as in participants with cognitive impairment, but no dementia (CIND). In cognitively well performing participants (n = 401), demographic variables and cognitive abilities (executive functions, reading comprehension, mental calculation, vocabulary) were associated with health numeracy. Older age, lower education, female gender as well as lower cognitive functions predicted low health numeracy. The effect of older age was partly mediated by executive functions and calculation abilities. Participants with CIND (n = 51) performed significantly lower than healthy controls in health numeracy. The findings suggest that cognitively well performing old individuals have difficulties in understanding health-related numerical information. The risk of misunderstanding health-related numerical information is increased in persons with CIND. As these population groups are frequently involved in health care decisions, particular attention has to be paid to providing numerical information in comprehensible form.     

Recognition memory deficits in mild cognitive impairment

ABSTRACT

There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (MCI). Whereas lower performance in recollection is the hallmark of MCI, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed light on the pattern of responding in recollection and familiarity in MCI. Five groups of participants were tested. The main participant samples were those formed by two MCI groups differing in age and an Alzheimer's disease group (AD), which were compared with two control groups. Whereas one of the control groups served to assess the performance of the MCI and AD people, the other one, composed of young healthy participants, served the purpose of evaluating the adequacy of the experimental tasks used in the evaluation of the different components of recognition memory. We used an associative recognition task as a direct index of recollection and a choice task on a pair of stimuli, one of which was perceptually similar to those studied in the associative recognition phase, as an index of familiarity. Our results indicate that recollection decreases with age and neurological status, and familiarity remains stable in the elderly control sample but it is deficient in MCI. This research shows that a unique encoding situation generated deficits in recollective and familiarity mechanisms in mild cognitive impaired individuals, providing evidence for the existence of deficits in both retrieval processes in recognition memory in a MCI stage.     

Body checking and avoidance in ethnically diverse female college students

Although body checking and avoidance behaviors are common in women with eating disorders, minimal research has examined the nature or correlates of these behaviors in ethnically diverse female college students without eating disorders. Self-identified European American (n = 268), Asian American (n = 163), Latina (n = 146), and African American (n = 73) women completed self-report measures of body checking and avoidance, thin-ideal internalization, eating pathology, and clinical impairment. Results indicated that European and Asian American women reported significantly more body checking and avoidance than African American and Latina women. Generally, correlates of body checking and avoidance were consistent across ethnic groups: Regression analyses indicated that type of ethnicity predicted body checking and avoidance; and ethnicity, body checking, and body avoidance predicted eating pathology and clinical impairment. These associations suggest that body checking and avoidance are not benign behaviors in diverse nonclinical women.