Biomedical subjects

Jill B Rich

Publications and source records attributed to Jill B Rich.

7 recordsLinked to original sources

PubMed2007

Developmental relations between working memory and inhibitory control.

Working memory (WM) and inhibitory control (IC) are general-purpose resources that guide cognition and behavior. In this study, the developmental relations between WM and IC were investigated in 96 typically developing children aged 6 to 17 years in an experimental task paradigm using an efficiency metric that combined speed and accuracy performance. The ability to activate and process information in WM showed protracted age-related growth. Performance involving WM and IC together was empirically distinguishable from that involving WM alone. The results indicate that developmental improvements in WM are attributable to increased processing efficiency in activation, suppression, and strategic resource deployment, and that WM and IC are best studied in novel, complex situations that elicit competition among those resources.

Child↗

PubMed2006

Diazepam-induced prospective memory impairment and its relation to retrospective memory, attention, and arousal.

The amnestic effects of benzodiazepines are well documented on a variety of memory tasks. However, prospective memory (PM), or remembering to execute an action at a future time, has not been studied previously. This study examined the effect of diazepam on word list recall, PM, sustained attention, and subjective ratings of arousal. Forty-eight healthy participants, aged 19-35, received an average of 0.19 mg/kg oral diazepam or placebo in a double-blind manner. Retrospective memory and PM were assessed by free recall of unrelated word lists and by instructing participants to request a hidden belonging at the end of the session, respectively. Sustained attention was measured by multiple trials of a digit cancellation task, and subjective arousal was assessed by self-ratings of drowsiness. Diazepam impaired performance on all measures, including PM. Reduced PM performance was associated with decreased subjective arousal in the diazepam group but was unrelated to sustained attention. This is the first report of the effects of benzodiazepines on prospective remembering, and further supports the view that the arousal/attentional system is composed of partially independent subsystems that have differential relationships to memory.

Adult↗

PubMed2006

Verbal fluency patterns in amnestic mild cognitive impairment are characteristic of Alzheimer's type dementia.

Amnestic mild cognitive impairment (aMCI) represents a high-risk factor for Alzheimer's disease (AD) and is characterized by a selective decline in episodic memory. Although by definition aMCI is not associated with impaired verbal fluency performance, we examined relative differences between fluency tasks because AD is characterized by poorer semantic than phonemic fluency. Phonemic and semantic fluency trials were administered to 46 healthy controls, 33 patients with aMCI, and 33 patients with AD. Results revealed a progressive advantage (controls > aMCI > AD) in semantic, relative to phonemic fluency. Difference scores between tasks distinguished each group from the others with medium to large effect sizes (d) ranging from 0.49 to 1.07. Semantic fluency relies more on semantic associations between category exemplars than does phonemic fluency. This aMCI fluency pattern reflects degradation of semantic networks demonstrating that initial neuropathology may extend beyond known early changes in hippocampal regions.

Aged↗

PubMed2006

Subject-performed tasks improve associative learning in amnestic mild cognitive impairment.

Subject-performed tasks (SPTs) may facilitate the deficit in associative learning among individuals with amnestic mild cognitive impairment (aMCI) by inducing episodic integration of object-action associations. To test this hypothesis, we examined free recall and recognition memory following enactment and verbal encoding in healthy elderly controls and individuals with aMCI. Study lists contained either semantically integrated ("Bounce the ball") or crossed object-action commands, in which episodic and semantic associations were placed in opposition ("Pet the compass"). Associative learning was indeed better after SPT than verbal encoding and with integrated relative to crossed lists for the aMCI group, as it was for controls. Moreover, the degree to which SPTs reduced the semantic interference inherent in the crossed conditions was equivalent for the two groups. The results showed that enactment facilitates formation of episodic associations, even when not supported by preexisting semantic knowledge, and even among individuals who have particular difficulty forming new associations.

Adult↗

PubMed2002

Implicit memory varies across the menstrual cycle: estrogen effects in young women.

Evidence that ovarian steroid hormones such as estrogen and progesterone affect cognition comes from studies of memory in older women receiving estrogen replacement therapy and studies of sexually dimorphic skills in young women across the menstrual cycle. Sixteen women (ages 18-28) completed tests of memory (implicit category exemplar generation, category-cued recall, implicit fragmented object identification) and sexually dimorphic skills (fine motor coordination, verbal fluency, mental rotations) at the early follicular (low estrogen and progesterone) and midluteal (high estrogen and progesterone) phases of the menstrual cycle. Performance on category exemplar generation, a test of conceptual implicit memory, was better at the midluteal than the follicular phase. In contrast, performance on a test of explicit memory, category-cued recall, did not vary across the menstrual cycle. At Session 1, women in the follicular phase performed better on the fragmented object identification task than did those in the midluteal phase. This unexpected finding suggests that high levels of ovarian hormones might inhibit perceptual object priming. Results confirmed previous reports of decreased mental rotations and improved motor skills and fluency in the midluteal phase. Estradiol levels correlated positively with verbal fluency and negatively with mental rotations and perceptual priming, which suggest that estrogen, and not progesterone, was responsible for the observed changes in cognition. Mood did not vary across the cycle phases. Overall, the findings suggest that estrogen may facilitate the automatic activation of verbal representations in memory.

Adult↗

PubMed2002

Psychometric properties of a new metamemory questionnaire for older adults.

Subjective memory ratings provide information that is distinct from objective memory performance, and there is a need for reliable and valid metamemory measures. The Multifactorial Memory Questionnaire (MMQ), developed to assess separate dimensions of memory ratings that are applicable to clinical assessment and intervention, includes scales of Contentment (i.e., affect regarding one's memory), Ability (i.e., self-appraisal of one's memory capabilities), and Strategy (i.e., reported frequency of memory strategy use). Among a group of 115 older adults, analyses revealed excellent content validity, factorial validity, test-retest and intratest reliability, convergent and discriminant construct validity, and independence from demographic variables. The psychometric strengths of the MMQ, together with descriptive statistics provided for healthy older adults, make this questionnaire useful in both clinical and research settings.

Age Factors↗

PubMed2002

What do Alzheimer's disease patients know about animals? It depends on task structure and presentation format.

Deficits on tasks requiring semantic memory in Alzheimer's disease (AD) may be due to storage loss, a retrieval deficit, or both. To address this question, we administered multiple tasks involving 9 exemplars of the category "animals," presented as both words and pictures, to 12 AD patients and 12 nondemented individuals. Participants made semantic judgments by class (sorting task), similarity (triadic comparison task), and dimensional attributes (ordering task). Relative to control participants, AD patients were impaired on an unstructured sorting task, but did not differ on a constrained sorting task. On the triadic comparison task, the patients were as likely to make judgments based on size as domesticity attributes, whereas control participants made judgments based primarily on domesticity. The patients' judgments were also less consistent across tasks than those of control participants. On the ordering tasks, performance was generally comparable between groups with pictures but not words, suggesting that pictures enable AD patients to access information from semantic memory that is less accessible with lexical stimuli. These results suggest that AD patients' semantic judgments are impaired when the retrieval context is unstructured, but perform normally under supportive retrieval conditions.

Aged↗