Episodic Free Recall Research Articles

Working memory predicts subsequent episodic memory decline during healthy cognitive aging: evidence from a cross-lagged panel design

ABSTRACTAging adults experience declines in working memory and episodic memory, however, it is unclear how these declines operate over time. Decreased working memory may be associated with early changes in episodic memory, by reducing older adults’ ability to meaningfully integrate new information into pre-existing schemas and recall information without the assistance of cues. Given the increased prevalence of Alzheimer’s disease, and concerns based on subjective memory changes, it is important to understand how these processes interact over time. To assess the relationship between working memory and episodic memory during healthy cognitive aging, we performed neuropsychological assessments at multiple time points in a sample of 310 community-dwelling older adults. Using a cross-lagged panel design, we demonstrated that the lagged associations between working memory and later episodic free recall were 50% larger than the lagged associations between episodic recall and later working memory, suggesting working memory may be a useful metric of future episodic memory decline.

Neuronal baseline shifts underlying boundary setting during free recall

Asked to freely recall items from a predefined set (e.g., animals), we rarely recall a wrong exemplar (e.g., a vegetable). This capability is so powerful and effortless that it is essentially taken for granted, yet, surprisingly, the underlying neuronal mechanisms are unknown. Here we investigate this boundary setting mechanism using intracranial recordings (ECoG), in 12 patients undergoing epilepsy monitoring engaged in episodic free recall. After viewing vivid photographs from two categories (famous faces and places), patients were asked to freely recall these items, targeting each category in separate blocks. Our results reveal a rapid and sustained rise in neuronal activity (“baseline shift”) in high-order visual areas that persists throughout the free recall period and reflects the targeted category. We further show a more transient reactivation linked to individual recall events. The results point to baseline shift as a flexible top−down mechanism that biases spontaneous recall to remain within the required categorical boundaries.

Sketching to remember: episodic free recall task support for child witnesses and victims with autism spectrum disorder.

Deficits in episodic free-recall memory performance have been reported in children with autism spectrum disorder (ASD), yet best practice dictates that child witness/victim interviews commence with a free-recall account. No 'tools' exist to support children with ASD to freely recall episodic information. Here, the efficacy of a novel retrieval technique, Sketch reinstatement of context (Sketch-RC), is compared with mental reinstatement of context and a no support control. Ninety children (45 with ASD; 45 matched typically developing) viewed a stimulus film, and were interviewed using one of the aforementioned techniques. The Sketch-RC technique was most effective, improving ASD participants' remembering without a concomitant increase in intrusions. This procedure offers a population-appropriate method for supporting free recall in criminal justice settings.

EPA-1715 – Cognitive deficits in old age – the influence of current depression and psychiatric history

Introduction Cognitive symptoms in depression are associated with high distress, poor functional outcome and more relapses. Variability in cognitive deficits in depression is often reported, and may originate from numerous factors; one rarely examined factor is psychiatric history. Objectives To assess the effects of depression and severe psychiatric history on old-age cognitive performance. Methods From a sample of non-demented participants (60+ years) in a population-based study receiving neuropsychological testing, three groups were formed based on information from the Swedish national inpatient register (1969-2005): current unipolar depression (ICD-10)/no psychiatric history (n=49), current unipolar depression/psychiatric history (n=16; F10-F45, F31-31.9 excluded), remission/history of mood disorders (n=35, F31-31.9 excluded). In addition, a group of healthy controls (n=98) was randomly selected. Results Currently depressed participants without psychiatric history performed at a lower level compared to healthy controls in processing speed, attention, executive function, verbal fluency, episodic free recall and vocabulary. However, remitted participants performed at the same level as healthy controls, and outperformed currently depressed with psychiatric history in verbal fluency. No group differences were observed for short term memory, episodic recognition, general knowledge or spatial ability. Conclusions Currently depressed without psychiatric history consistently performed at the lowest level. The proportion receiving psychopharmacological treatment in this group was low, 6.1% compared to 56.2% and 37.1%, which may partially account for this finding. Additional factors potentially explaining why remitted participants and healthy controls perform at the same level cognitively will be examined. These findings may have important implications for preventing residual cognitive deficits in depression.

2681 – Cognitive deficits in unipolar old-age depression: a population-based study

Introduction Recognition of cognitive deficits in old-age depression is especially important since they contribute to poor function outcome, have strong implications for coping abilities and treatment compliance. However, substantial variability in cognitive deficits among older depressed persons has been reported. Clinical and demographic characteristics are likely to have contributed to inconsistencies in previous findings. Objective To assess effects of unipolar depression on cognitive performance in a population-based sample of elderly persons (60+ years). Methods An extensive cognitive test battery was administered. Eighty-nine persons fulfilled ICD-10 criteria for unipolar depression (mild, n=48; moderate; n=38, severe; n=3) after thorough screening for dementia (DSM-IV criteria), psychiatric comorbidities, antidepressant pharmacotherapy, and lastly preclinical dementia. Results Unipolar old-age depression was associated with deficits in processing speed, attention, executive function, verbal fluency, and episodic free recall. No depression-related deficits were observed in short-term memory, semantic memory, or spatial ability. Increasing age did not exacerbate the cognitive deficits in old-age depression. The cognitive deficits remained significant after exclusion of persons with preclinical dementia, except free recall, where performance differences were at trend level. Conclusions Cognitive deficits in unipolar old-age depression involve a number of cognitive domains, and are also present among persons with mild depression. Importantly, no statistically significant performance differences between mild and moderate/severe depression were observed. Given the prevalence of depression in older populations, the impact of this disorder on cognitive functioning may be relatively large at the population level.

Effects of semantic relatedness on recall of stimuli preceding emotional oddballs

Semantic and episodic memory networks function as highly interconnected systems, both relying on the hippocampal/medial temporal lobe complex (HC/MTL). Episodic memory encoding triggers the retrieval of semantic information, serving to incorporate contextual relationships between the newly acquired memory and existing semantic representations. While emotional material augments episodic memory encoding at the time of stimulus presentation, interactions between emotion and semantic memory that contribute to subsequent episodic recall are not well understood. Using a modified oddball task, we examined the modulatory effects of negative emotion on semantic interactions with episodic memory by measuring the free-recall of serially presented neutral or negative words varying in semantic relatedness. We found increased free-recall for words related to and preceding emotionally negative oddballs, suggesting that negative emotion can indirectly facilitate episodic free-recall by enhancing semantic contributions during encoding. Our findings demonstrate the ability of emotion and semantic memory to interact to mutually enhance free-recall.

Going beyond a single list: Modeling the effects of prior experience on episodic free recall

We present an extension of the search of associative memory (SAM) model that simulates the effects of both prior semantic knowledge and prior episodic experience on episodic free recall. The model incorporates a memory store for preexisting semantic associations, a contextual drift mechanism, a memory search mechanism that uses both episodic and semantic associations, and a large lexicon including both words from prior lists and unpresented words. These features enabled the model to successfully account for the effects of prior semantic knowledge and prior episodic learning on the pattern of correct recalls and intrusions observed in free recall experiments.

Smoking attenuates regular aerobic exercise benefits to episodic free recall immediately following strenuous physical activity

AbstractThe present study was designed to evaluate the extent to which free recall performance is influenced by competing demands on physiological resources dependent on blood‐oxygen levels. Fifty‐six healthy young adults (mean age=20 years) were allocated to groups (n1–4=14) according to their level of exercise (more than 6 h aerobic exercise per wk, or sedentary1Here sedentary refers to individuals with no regular exercise routines .) and smoking (more than 10 cigarettes per day, or none) behaviour. Participants performed two free recall tasks, one under normal physically inactive conditions and the other immediately following strenuous physical exertion (a step‐up test for 2 min). We predicted that recall would suffer following strenuous physical activity among smoking aerobic exercisers. We reasoned this would be due to the oxygen‐carrying capacity of the blood being compromised in this group by higher levels of smoking‐related carbon monoxide in the blood stream. The results supported this prediction. We interpret our findings according to a resource model of cognitive function, mediated by physiological mechanisms. Copyright © 2004 John Wiley & Sons, Ltd.

Utilization of cognitive support in episodic free recall as a function of apolipoprotein E and vitamin B12 or folate among adults aged 75 years and older.

Apolipoprotein E (APOE), vitamin B12, and folate were examined in relation to free recall among 167 community-based older adults. Cognitive support at encoding and retrieval was also taken into account. Participants were classified as APOE e4 or non-epsilon4 allele carriers and as either low or normal vitamin B12 or folate status. A significant association was identified between low vitamin B12 and the epsilon4 genotype in respect to free recall, but only in circumstances of low cognitive support. This result remained after removing dementia cases that occurred up to 6 years after testing. A similar, but nonsignificant, trend was evident in relation to folate. The research is discussed with reference to vulnerability models and genetic influences on brain reserves.