Effectiveness of tDCS to Improve Recognition and Reduce False Memories in Older Adults

Background. False memories tend to increase in healthy and pathological aging, and their reduction could be useful in improving cognitive functioning. The objective was to use an active-placebo method to verify whether the application of tDCS in improving true recognition and reducing false memories in healthy older people. Method. Participants were 29 healthy older adults (65-78 years old) assigned to active or placebo group; active group received anodal stimulation at 2mA for 20 min over F7. An experimental task was used to estimate true and false recognition. The procedure took place in two sessions on two consecutive days. Results. A mixed ANOVA of true recognition showed a significant …

Effects of Stimuli Repetition and Age in False Recognition

The aim of the current study is to examine the effects of stimuli repetition and age in false recognition using the Deese–Roediger–McDermott experimental paradigm. Two matched samples of 32 young adults and 32 healthy older adults studied 10 lists of six words associated with three non-presented critical words. On half of the lists, the words were presented once, and on the other five lists, the words were presented three times, always following a same sequential order. After each study list, participants performed a self-paced recognition test containing 12 words: the 6 studied words and 6 other non-studied words (the 3 critical words and 3 distractors). The results show that false recogn…

Effects of bilingualism on white matter atrophy in mild cognitive impairment: a diffusion tensor imaging study

Background and purpose Previous investigations show that bilinguals exhibit the first symptoms of dementia 4-5 years later than monolinguals. Therefore, bilingualism has been proposed as a cognitive reserve mechanism. Recent studies have advanced towards an understanding of the brain mechanisms underlying bilingualism's protection against dementia, but none of them deals with white matter (WM) diffusion. Methods In this study, the topic was investigated by measuring WM integrity in a sample of 35 bilinguals and 53 passive bilinguals with mild cognitive impairment. Results No significant differences were found between the groups in cognitive level, education, age or sex. However, bilinguals …

Executive Functions, Episodic Autobiographical Memory, Problem-Solving Capacity, and Depression Proposal for a Structural Equations Model

The executive functions play an important role in storing and recovering autobiographical memories, especially episodic memories. These types of memories provide information about solutions and experiences from the past that can be utilized as examples in the present when seeking solutions to any problem. In addition, a close relationship between depression and the executive functions has been widely recognized. This study aims to elaborate a structural equations model that empirically supports the relationships among the executive functions, episodic autobiographical memory, and the adaptive capacity to solve problems, taking into account the depressed mood state. In all, 32 healthy elder…

P3‐061: Familiarity‐based recognition in multidomain amnestic and nonamnestic cognitive impaired patients: A follow‐up retest

Associative and implicit memory performance as a function of cognitive reserve in elderly adults with and without mild cognitive impairment

AbstractThis study aims to analyze implicit and explicit memory performance as a function of cognitive reserve (CR) in a healthy control group (N = 39) and a mild cognitive impairment (MCI) group (N = 37). Both groups were subdivided into high and low cognitive reserve, and were asked to complete an explicit and implicit associative recognition tasks. The results showed that the control group was able to learn both tasks (η2 = .19, p < .0001), and the high CR group fared better (η2 = .06, p < .05). The MCI sample, conversely, was unable to learn the implicit relationship, and showed very little learning on the explicit association task. Participants diagnosed with MCI showed little pl…

Conflict monitoring on an emotional Stroop task. Comparison of healthy older adults and patients with major neurocognitive disorders due to probable AD.

The conflict monitoring system exerts an influence on centers responsible for cognitive control, causing them to intervene more strongly in processing when conflict occurs. These mechanisms are usually investigated through specific tasks where there is an inherent interference elicited by the congruency or incongruency between the stimuli and responses, such as the Stroop task. In studies of emotional conflict, one hypothesis related to the dorsal anterior cingulate cortex (ACC) is that it serves, in part, to signal the appearance of conflicts, thus triggering compensatory adjustments. This study aims to verify whether the conflict monitoring hypothesis is confirmed in a group with Alzheime…

Genistein effect on cognition in prodromal Alzheimer's disease patients : the GENIAL clinical trial

Background: Delaying the transition from minimal cognitive impairment to Alzheimer’s dementia is a major concern in Alzheimer’s disease (AD) therapeutics. Pathological signs of AD occur years before the onset of clinical dementia. Thus, long-term therapeutic approaches, with safe, minimally invasive, and yet efective substances are recommended. There is a need to develop new drugs to delay Alzheimer’s dementia. We have taken a nutritional supplement approach with genistein, a chemically defned polyphenol that acts by multimodal specifc mechanisms. Our group previously showed that genistein supplementation is efective to treat the double transgenic (APP/PS1) AD animal model. Methods: In this…

Additional file 1 of Genistein effect on cognition in prodromal Alzheimer’s disease patients. The GENIAL clinical trial

Additional file 1: Table S1. All possible comparisons of the values for the anterior cingulate gyrus before and after treatment with placebo or genistein.

Differences in false recollection according to the cognitive reserve of healthy older people

We present an associative recognition experiment comparing three samples of healthy people (young people, older people with high cognitive reserve [HCR], and older people with low cognitive reserve [LCR], with each sample consisting of 40 people), manipulating stimuli repetition during the study phase. The results show significant differences among the three samples in their overall performance. However, these differences are not due to a different use of familiarity, but rather due to a different way of using recollection: although there are no differences in the hit rates between the HRC and LRC samples, the LCR group makes significantly more recollective false alarms than the HCR group. …

False memories in Lewy-body disease.

Recently, de Boysson et al. (2011) [de Boysson, C., et al. (2011). False recognition in Lewy-body disease and frontotemporal dementia. Brain and Cognition, 75, 111-118.] found that patients with Lewy-body disease (LBD) showed significantly lower rates of false memories than healthy controls, using the Deese¿Roediger¿McDermott (DRM) experimental procedure. Given that this result could be explained by the practically null rate of true recognition in the LBD group (0.09), we decided to replicate the study by de Boysson et al. (2011), but including a new condition that would maximize the true recognition rate (and analyze its effect on the rate of false memories). Specifically, in a DRM experim…

Recognition memory deficits in mild cognitive impairment

There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (Mel). Whereas lower performance in recollection is the hallmark of Mel, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed Iight on the pattern of responding in recollection and familiarity in MCl. Five groups of participants were tested. The main participant samples were those formed by two Mel 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 p…

Effectiveness of tDCS at Improving Recognition and Reducing False Memories in Older Adults

Background: False memories tend to increase in healthy and pathological aging, and their reduction could be useful in improving cognitive functioning. The objective of this study was to use an active–placebo method to verify whether the application of transcranial direct current stimulation (tDCS) improved true recognition and reduced false memories in healthy older people. Method: Participants were 29 healthy older adults (65–78 years old) that were assigned to either an active or a placebo group

Familiarity-based recognition in the young, healthy elderly, mild cognitive impaired and Alzheimer's patients

This study investigates the possible existence of deficits in familiarity in five samples of participants spanning a broad range of ages and cognitive states. Five groups of 16 participants with a diagnosis of multi-domain cognitive impairment with a slight or no deficit in memory, 16 multi-domain amnestic, and 16 Alzheimer's disease patients were compared in a recognition test with equivalent samples of old and young healthy participants. In one of the tests, participants studied words extracted from a restricted set of letters of the alphabet that were later mixed with new words from a different set. The unconscious use of the fluency produced by the repeated use of the set of letters was…

Wellbeing, resilience, and coping: Are there differences between healthy older adults, adults with mild cognitive impairment, and adults with Alzheimer-type dementia?

The changes that occur with cognitive impairment and Alzheimer's disease could affect psychological aspects unrelated to memory. The purpose of this study is to compare 32 healthy older adults, 31 amnestic mild cognitively impaired (aMCI) adults, and 32 patients diagnosed with Alzheimer's disease (AD), in order to determine whether there are differences in their psychological wellbeing, resilience, and coping strategies. Unifactorial MANOVAS and ANOVAS were performed to analyze the between-group differences. The results reveal that the AD group showed lower levels of resilience and orientation toward problem-solving and greater use of religious strategies. In addition, they had significantl…

On familiarity deficits in mild cognitive impairment: A reply to Migo and Westerberg

ABSTRACTIn this brief response to Migo and Westerberg we explain why we think that their criticism of our previous research showing familiarity deficits in mild cognitive impairment patients (MCI) is not sound. More concretely, we have replicated the effect several times previously, and we justify statistically the fact that in the previous paper we had to combine two MCI samples to demonstrate a reliable familiarity deficit. We note that there are several studies showing conflicting results. However, although the basis for these discrepancies remains uncertain, a new report has replicated the presence of deficits in familiarity, and more importantly, demonstrated its correlation with struc…

Complexity analysis of cortical surface detects changes in future Alzheimer's disease converters

Alzheimer's disease (AD) is a neurological disorder that creates neurodegenerative changes at several structural and functional levels in human brain tissue. The fractal dimension (FD) is a quantitative parameter that characterizes the morphometric variability of the human brain. In this study, we investigate spherical harmonic-based FD (SHFD), thickness, and local gyrification index (LGI) to assess whether they identify cortical surface abnormalities toward the conversion to AD. We study 33 AD patients, 122 mild cognitive impairment (MCI) patients (50 MCI converters and 29 MCI nonconverters), and 32 healthy controls (HC). SHFD, thickness, and LGI methodology allowed us to perform not only …

Recognition by familiarity is preserved in Parkinson's without dementia and Lewy-Body disease.

Objective The retrieval deficit hypothesis states that the lack of deficit in recognition often observed in patients with Parkinson's disease is because of the low retrieval requirements of the task, given that these patients have retrieval and not encoding deficits. To test this hypothesis we investigated recognition memory by familiarity in Parkinson's patients and in patients with Lewy Bodies disease and Parkinson with dementia. Method We analyzed to what extent the experimental groups were able to recognize by familiarity in a typical yes/no recognition memory task. The experimental groups were patients with early nondemented Parkinson's disease, advanced nondemented Parkinson's disease…

Phonological false recognition produced by bottom-up automatic activation in young and older people

Two experiments explored a new procedure to implicitly induce phonological false memories in young and older people. On the study tasks, half of the words were formed from half of the letters in the alphabet, whereas the remaining words were formed from all the letters in the alphabet. On the recognition tests, there were three types of non-studied new words: critical lures formed from the same half of the letters as the studied words; distractors formed from the other half of the letters not used, and distractors formed from all the letters in the alphabet. In both experiments, the results showed that, in both young and older people, critical lures produced more false recognitions than dis…

Can there be learning potential in Parkinson’s disease? A comparison with healthy older adults

Patients with Parkinson's disease may show certain cognitive impairments, although it is unclear how these deficits can affect their learning potential. The study aims to use the testing-the-limits technique to compare the potential for cognitive plasticity in a group of Patients with Parkinson's disease (N = 33) and a group of healthy older adults (N = 33). Sixty-six participants performed verbal learning test to analyze the learning potential. Repeated-measures analysis of variance showed significant main effects of time, group, and the interaction. There is a lower learning potential in subjects with Parkinson's disease; however, those still maintain a certain capacity for learning and, …

The use of Alzheimer CSF biomarkers in daily clinical practice

Motivated forgetting reduces veridical memories but slightly increases false memories in both young and healthy older people.

The aim of the current study is to examine the effects of motivated forgetting and aging on true and false memory. Sixty young and 54 healthy older adults were instructed to study two lists of 18 words each. Each list was composed of three sets of six words associated with three non-presented critical words. After studying list 1, half of the participants received the instruction to forget List 1, whereas the other half received the instruction to remember List 1. Next, all the subjects studied list 2; finally, they were asked to remember the words studied in both lists. The results showed that when participants intended to forget the studied List 1, they were less likely to recall the stud…

Exploring recollection and familiarity impairments in Parkinson’s disease

There is conflicting evidence on whether patients diagnosed with Parkinson's disease (PD) have cognitive deficits associated with episodic memory and particularly with recognition memory. The aim of the present study was to explore whether PD patients exhibit deficits in recollection and familiarity, the two processes involved in recognition. A sample of young healthy participants (22) was tested to verify that the experimental tasks were useful estimators of recognition processes. Two further samples ¿ one of elderly controls (16) and one of PD patients (20) ¿ were the main focus of this research. All participants were exposed to an associative recognition task aimed at estimating recollec…

Differences on autobiographical memory in healthy aging and Alzheimer’s disease

A cross-sectional and longitudinal study on the protective effect of bilingualism against dementia using brain atrophy and cognitive measures.

Abstract Background Evidence from previous studies suggests that bilingualism contributes to cognitive reserve because bilinguals manifest the first symptoms of Alzheimer’s disease (AD) up to 5 years later than monolinguals. Other cross-sectional studies demonstrate that bilinguals show greater amounts of brain atrophy and hypometabolism than monolinguals, despite sharing the same diagnosis and suffering from the same symptoms. However, these studies may be biased by possible pre-existing between-group differences. Methods In this study, we used global parenchymal measures of atrophy and cognitive tests to investigate the protective effect of bilingualism against dementia cross-sectionally …

The effects of healthy aging, amnestic mild cognitive impairment, and Alzheimer's disease on recollection, familiarity and false recognition, estimated by an associative process-dissociation recognition procedure

Given the uneven experimental results in the literature regarding whether or not familiarity declines with healthy aging and cognitive impairment, we compare four samples (healthy young people, healthy older people, older people with amnestic mild cognitive impairment - aMCI -, and older people with Alzheimer's disease - AD -) on an associative recognition task, which, following the logic of the process-dissociation procedure, allowed us to obtain corrected estimates of recollection, familiarity and false recognition. The results show that familiarity does not decline with healthy aging, but it does with cognitive impairment, whereas false recognition increases with healthy aging, but decli…

The Role of Recollection and Familiarity in Nondemented Parkinson's Patients

The aim of the current study was to examine if recollection and familiarity decline in nondemented Parkinson's patients. To do so we compared a sample of older people with Parkinson's disease (n = 32) to a control sample of healthy older people (n = 32) on an associative recognition task in which we manipulated the repetition of the pairs during the study phase (half of the pairs were presented once and half twice) to obtain corrected estimates of recollection, familiarity, and false recognition based on the logic of the process-dissociation procedure. The results clearly show that recollection is impaired but familiarity is preserved in nondemented Parkinson's patients. The results show th…