Free Recall Memory Research Articles

CHARACTERIZING MEMORY PROCESSING ACROSS THE HUMAN LIFESPAN: A LARGE SAMPLE ANALYSIS USING HIERARCHICAL BAYESIAN COGNITIVE PROCESSING MODELS

As the research focus shifts toward the earlier identification and treatment of Alzheimer's disease (AD), a more sophisticated approach for characterizing cognitive function is needed. Using cognitive processing models combined with hierarchical Bayesian methods (HBCP) is one approach for estimating underlying cognitive processes and variables that cannot be measured using traditional scorning methods. HBCP models were applied to a wordlist memory task in normal aging subjects to characterize changes in underlying processes. 681,428 normal subjects, aged 15-100 years old (Figure 1), were assessed with free recall and recognition memory tasks. The raw score data were the proportion of words correctly recalled overall, of first (primacy) and last (recency) list words recalled, and of words correctly recognized overall. Hits and false alarms were also tracked. One HBCP applied a primacy-recency model of serial position effects to the free recall data (Figure 2a). The other HBCP applied an equal-variance signal detection theory model of discriminability and response bias to the recognition data (Figure 2b). The cognitive processing parameters of each individual were drawn from an assumed Gaussian distribution for their age. For each age, the mean value and the 90% credible intervals were plotted, within which a new individual's parameter values would fall. Mean raw recall scores overall and for primacy (first word) decline after 70 (Figure 3) while the HBCP model of the primacy parameter more sharply declines after 70 years old than the raw primacy scores (Figure 4). Mean raw hit and overall recognition rates slightly decline, and false alarm rates slightly increase after 70 years old (Figure 5) while the HBCP model shows that discriminability gradually declines, and response bias gradually increases over the entire lifespan (Figure 6).

The impact of different background noises on the Production Effect

The presence of background noise has been previously shown to disrupt cognitive performance, especially memory. The amount of interference is derived from the acoustic characteristics of the noise; energetic vs. informational, steady-state vs. fluctuating. However, the literature is inconsistent concerning the effects of different types of noise on long-term memory free recall. In the present study, we tested the impact of different noises on recall of items that were learned under two conditions – silent or aloud reading, a Production Effect (PE) paradigm. As the PE represents enhanced memory for words read aloud relative to words read silently during study, we focused on the effect of noise on this robust memory phenomenon. The results showed that (a) steady-state energetic noise did not affect memory, with a recall advantage for aloud words (PE), comparable to a no-noise condition, (b) fluctuating-energetic noise and fluctuating-informational (eight-talkers babble) noise eliminated the PE, with similar recall for aloud and silent items. These results are discussed in light of their theoretical implications, stressing the role of attention in the PE. Ecological implications regarding studying in noisy environments are suggested.

Can implicit measures detect source information in crime-related amnesia?

ABSTRACTParticipants who are asked to simulate amnesia for a mock crime have a weaker memory for this event when they have to give up their role as a feigner, than those who are not asked to feign memory loss. According to the source monitoring framework (SMF), this memory-undermining effect of simulating amnesia for a crime would be due to misattribution of the right source of information. However, we know that the content of self-generated information (e.g., feigned version of the crime) might be preserved and recognised over time as a result of elaborative cognitive processing. In the present study, we aimed to contrast these two explanations. We showed participants a mock crime video and we instructed them to either feign amnesia (simulators) or confess the mock crime (confessors). Next, a free recall memory test was administered. After one week, participants were asked to perform a personalised source monitoring task using the autobiographical Implicit Association Test (aIAT). As predicted, we found that simulators were able to discriminate the content of their self-generated feigned story of the crime from the original version. Moreover, simulators were quicker than confessors at the aIAT task. Practical and theoretical implications of our results are discussed.

An item-level analysis of lexical-semantic effects in free recall and recognition memory using the megastudy approach.

Psycholinguists have developed a number of measures to tap different aspects of a word's semantic representation. The influence of these measures on lexical processing has collectively been described as semantic richness effects. However, the effects of these word properties on memory are currently not well understood. This study examines the relative contributions of lexical and semantic variables in free recall and recognition memory at the item-level, using a megastudy approach. Hierarchical regression of recall and recognition performance on a number of lexical-semantic variables showed task-general effects where the structural component, frequency, number of senses, and arousal accounted for unique variance in both free recall and recognition memory. Task-specific effects included number of features, imageability, and body-object interaction, which accounted for unique variance in recall, whereas age of acquisition, familiarity, and extremity of valence accounted for unique variance in recognition. Forward selection regression analyses generally converged on these findings. Hierarchical regression also revealed that lexical variables accounted for more variance in recognition compared with recall, whereas semantic variables accounted for more unique variance above and beyond lexical variables in recall compared with recognition. Implications of the findings are discussed.

Reward anticipation modulates the effect of stress-related increases in cortisol on episodic memory

When acute stress is experienced shortly after an event is encoded into memory, this can slow the forgetting of the study event, which is thought to reflect the effect of cortisol on consolidation. In addition, when events are encoded under conditions of high reward they tend to be remembered better than those encoded under non-rewarding conditions, and these effects are thought to reflect the operation of the dopaminergic reward system. Although both modulatory systems are believed to impact the medial temporal lobe regions critical for episodic memory, the manner, and even the extent, to which these two systems interact is currently unknown. To address this question in the current study, participants encoded words under reward or non-reward conditions, then one half of the participants were stressed using the social evaluation cold pressor task and the other half completed a non-stress control task. After a two-hour delay, all participants received a free recall and recognition memory test. There were no significant effects of stress or reward on overall memory performance. However, for the non-reward items, increases in stress-related cortisol in stressed participants were related to increases in recall and increases in recollection-based recognition responses. In contrast, for the reward items, increases in stress-related cortisol were not related to increases in memory performance. The results indicate that the stress and the reward systems interact in the way they impact episodic memory. The results are consistent with tag and capture models in the sense that cortisol reactivity can only affect non-reward items because plasticity-related products are already provided by reward anticipation.

Effects of grasp compatibility on long-term memory for objects

Previous studies have shown action potentiation during conceptual processing of manipulable objects. In four experiments, we investigated whether these motor actions also play a role in long-term memory. Participants categorized objects that afforded either a power grasp or a precision grasp as natural or artifact by grasping cylinders with either a power grasp or a precision grasp. In all experiments, responses were faster when the affordance of the object was compatible with the type of grasp response. However, subsequent free recall and recognition memory tasks revealed no better memory for object pictures and object names for which the grasp affordance was compatible with the grasp response. The present results therefore do not support the hypothesis that motor actions play a role in long-term memory.

The Effects of Cognitive Reappraisal and Expressive Suppression on Memory of Emotional Pictures.

In the field of emotion research, the influence of emotion regulation strategies on memory with emotional materials has been widely discussed in recent years. However, existing studies have focused exclusively on regulating negative emotion but not positive emotion. Therefore, in the present study, we investigated the influence of emotion regulation strategies for positive emotion on memory. One hundred and twenty college students were selected as participants. Emotional pictures (positive, negative and neutral) were selected from Chinese Affective Picture System (CAPS) as experimental materials. We employed a mixed, 4 (emotion regulation strategies: cognitive up-regulation, cognitive down-regulation, expressive suppression, passive viewing) × 3 (emotional pictures: positive, neutral, negative) experimental design. We investigated the influences of different emotion regulation strategies on memory performance, using free recall and recognition tasks with pictures varying in emotional content. The results showed that recognition and free recall memory performance of the cognitive reappraisal groups (up-regulation and down-regulation) were both better than that of the passive viewing group for all emotional pictures. No significant differences were reported in the two kinds of memory scores between the expressive suppression and passive viewing groups. The results also showed that the memory performance with the emotional pictures differed according to the form of memory test. For the recognition test, participants performed better with positive images than with neutral images. Free recall scores with negative images were higher than those with neutral images. These results suggest that both cognitive reappraisal regulation strategies (up-regulation and down-regulation) promoted explicit memories of the emotional content of stimuli, and the form of memory test influenced performance with emotional pictures.

Narrative Skills, Gender, Culture, and Children’s Long-Term Memory Accuracy of a Staged Event

ABSTRACTThis study examined the extent to which school-aged children’s general narrative skills provide cognitive benefits for accurate remembering or enable good storytelling that undermines memory accuracy. European American and Chinese American 6-year-old boys and girls (N = 114) experienced a staged event in the laboratory and were asked to tell a story from a picture book that accessed their narrative skill. Children were interviewed about the staged event 6 months later to assess memory accuracy. Greater narrative skill when storytelling was associated with decreased free recall and recognition memory accuracy for the staged event. In free recall responses, this effect was driven by an increase in the likelihood that inaccurate details would be included in responses from children with better general narrative skills. For girls only, narrative skill predicted poorer recognition accuracy. Girls were also more language-proficient and provided more correct details in free recall than did boys. Chinese American children were more accurate than European American children when responding to recall prompts due to less frequent provision of incorrect details, particularly in girls. Findings are discussed in light of the roles of socialization in memory-reporting accuracy.

Production on hold: delaying vocal production enhances the production effect in free recall

ABSTRACTThe Production Effect (PE) represents superior memory for produced (read aloud) relative to non-produced (silently read) items. Another method of improving memory is taking a test on the study material – the Testing Effect. We evaluated the combined influence of both effects on free recall memory, using delayed vocal production, in which study words were vocally produced only after their disappearance. Such procedure involves an initial instant test since participants had to vocally retrieve the words (rather than read them aloud). In five experiments, participants were presented with study words that they were instructed to learn by no-production (reading silently), immediate production (reading aloud), delayed reading aloud, or delayed vocal production (instant retrieval). The results showed superior recall for delayed production over all other conditions. We suggest that the source of this superiority is the desirable difficulty induced by the addition of the initial test (retrieval effort) to the vocal production. The novel delayed production condition forms a superior mnemonic.

Regional gray matter correlates of memory for emotion-laden words in middle-aged and older adults: A voxel-based morphometry study.

Emotional content is known to enhance memory in a content-dependent manner in healthy populations. In middle-aged and older adults, a reduced preference for negative material, or even an enhanced preference for positive material has been observed. This preference seems to be modulated by the emotional arousal that the material evokes. The neuroanatomical basis for emotional memory processes is, however, not well understood in middle-aged and older healthy people. Previous research on local gray matter correlates of emotional memory in older populations has mainly been conducted with patients suffering from various neurodegenerative diseases. To our knowledge, this is the first study to examine regional gray matter correlates of immediate free recall and recognition memory of intentionally encoded positive, negative, and emotionally neutral words using voxel-based morphometry (VBM) in a sample of 50-to-79-year-old cognitively intact normal adults. The behavioral analyses yielded a positivity bias in recognition memory, but not in immediate free recall. No associations with memory performance emerged from the region-of-interest (ROI) analyses using amygdalar and hippocampal volumes. Controlling for total intracranial volume, age, and gender, the whole-brain VBM analyses showed statistically significant associations between immediate free recall of negative words and volumes in various frontal regions, between immediate free recall of positive words and cerebellar volume, and between recognition memory of positive words and primary visual cortex volume. The findings indicate that the neural areas subserving memory for emotion-laden information encompass posterior brain areas, including the cerebellum, and that memory for emotion-laden information may be driven by cognitive control functions.

Differences in emotional stimuli processing in subjects with MTLE with and without depression.

In healthy people, a preference in attention maintenance and memory for words with emotional valence comparing to neutral words has been shown. The pattern of emotional stimuli processing may be different in people with mesial temporal lobe epilepsy (MTLE) and it may be sensitive to the presence of depressive symptoms. In order to explore these possibilities, we applied the emotional spatial cueing attentional task and the free recall memory task to participants (N=39) with MTLE and compared them with healthy controls. We hypothesized that the pattern of maintaining attention and remembering emotional words is different in people with MTLE. Current literature indicates that this pattern will change from positive bias in the controls, though no emotional bias in the participants with MTLE without depression (MTLE-d), and in this work we examined this pattern in the participants with MTLE with depressive symptoms (MTLE+d). Our results show that in both attention and memory, control subjects exhibit positive emotional bias, the subjects with MTLE-d show nonemotional bias and the subjects with MTLE+d have bias away from positive words. Participants with MTLE+d maintained attention for positive words shorter than others. Participants with MTLE+d had worse recall for positive words than the participants with MTLE-d and for all words when compared to controls. We found that faster attention disengagement from positive words and worse memory for positive words is associated with elevated levels of depressive symptoms.

“I Think He Had A Tattoo On His Neck”: How Co-Witness Discussions About A Perpetrator's Description Can Affect Eyewitness Identification Decisions

This experiment was designed to examine the effect of misinformation imparted through co-witness discussions on memory reports and line-up decisions obtained after varied retention intervals. Participants viewed a simulated car-jacking and then heard co-witnesses describe their memory for the event. Confederate accounts included three plausible and three implausible pieces of misinformation. Memory for the event was assessed after five minutes, 50 minutes, two days, or one week. In addition to examining free-recall memory, we also looked at how misinformation about the perpetrator's appearance affected recognition memory by obtaining identifications from culprit-present and absent lineups. One of the confederates falsely described the perpetrator having a tattoo on his neck, and one lineup filler had this feature. Results revealed that mistaken identifications of the tattooed filler increased significantly at the longer retention intervals, while recall for the misinformation decreased at the longer intervals. Also, as expected, plausible misinformation was recalled more often than implausible.

The effects of synthetic cannabinoids on executive function.

There is a growing use of novel psychoactive substances (NPSs) including synthetic cannabinoids. Synthetic cannabinoid products have effects similar to those of natural cannabis but the new synthetic cannabinoids are more potent and dangerous and their use has resulted in various adverse effects. The purpose of the study was to assess whether persistent use of synthetic cannabinoids is associating with impairments of executive function in chronic users. A total of 38 synthetic cannabinoids users, 43 recreational cannabis users, and 41 non-user subjects were studied in two centers in Hungary and Israel. Computerized cognitive function tests, the classical Stroop word-color task, n-back task, and a free-recall memory task were used. Synthetic cannabinoid users performed significantly worse than both recreational and non-cannabis users on the n-back task (less accuracy), the Stroop task (overall slow responses and less accuracy), and the long-term memory task (less word recall). Additionally, they have also shown higher ratings of depression and anxiety compared with both recreational and non-users groups. This study showed impairment of executive function in synthetic cannabinoid users compared with recreational users of cannabis and non-users. This may have major implications for our understanding of the long-term consequences of synthetic cannabinoid based drugs.

Effects of Isometric Hand-Grip Muscle Contraction on Young Adults' Free Recall and Recognition Memory

Purpose: The purpose of this study was to determine if physical arousal produced by isometric hand-dynamometer contraction performed during word-list learning affects young adults' free recall or recognition memory. Method: Twenty-four young adults (12 female; Mage = 22 years) were presented with 4 20-item word lists. Moderate arousal was induced in 12 adults by an initial 30-s maximal hand-dynamometer squeeze with force productions of 50% maximum; low arousal was induced in 12 adults by an initial 1-s maximal dynamometer squeeze with force production of 10% maximum during learning. Memory performances following dual-task conditions experienced during the encoding, consolidation, and recall phases of learning were compared to a single-task control condition during which words were learned in the absence of isometric exercise. Results: Planned contrasts revealed that arousal coinciding with word encoding led to significantly poorer immediate recall, F(1, 23) = 10.13, p < .05, = .31, delayed free recall, F(1, 23) = 15.81, p < .05, = .41, and recognition memory, F(1, 23) = 6.07, p < .05, = .21, compared with when there was no arousal. Neither arousal condition facilitated participants' memory performance. Conclusion: The reduction in long-term memory performance specific to the encoding phase of learning is explained in terms of the dual-task attentional demands placed on participants.

Orthographic neighborhood effects in recognition and recall tasks in a transparent orthography.

The number of orthographic neighbors of a word influences its probability of being retrieved in recognition and free recall memory tests. Even though this phenomenon is well demonstrated for English words, it has yet to be demonstrated for languages with more predictable grapheme-phoneme mappings than English. To address this issue, 4 experiments were conducted to investigate effects of number of orthographic neighbors (N) and effects of frequency of occurrence of orthographic neighbors (NF) on memory retrieval of Brazilian Portuguese words. One hundred twenty-four Brazilian Portuguese speakers performed first a lexical-decision task (LDT) on words that were factorially manipulated according to N and NF, and intermixed with either nonpronounceable nonwords without orthographic neighbors (Experiments 1A and 2A), or with pronounceable nonwords with a large number of orthographic neighbors (Experiments 1B and 2B). The words were later used as probes on either recognition (Experiments 1A and 1B) or recall tests (Experiments 2A and 2B). Words with 1 orthographic neighbor were consistently better remembered than words with several orthographic neighbors in all recognition and recall tests. Notably, whereas in Experiment 1A higher false alarm rates were yielded for words with several rather than 1 orthographic neighbor, in Experiment 1B higher false alarm rates were yielded for words with 1 rather than several orthographic neighbors. Effects of NF, on the other hand, were not consistent among memory tasks. The effects of N on the recognition and recall tests conducted here are interpreted in light of dual process models of recognition. (PsycINFO Database Record

Contralateral interictal and ictal EEG epileptiform activity accentuate memory impairment in unilateral mesial temporal sclerosis patients.

Memory impairment is a recognized complication of mesial temporal sclerosis (MTS). Epileptiform activity may negatively impact on cognition. We evaluated the impact of contralateral EEG involvement on memory in unilateral MTS (uMTS) patients. Retrospective review of 121 right-handed uMTS patients (69 left) evaluated with prolonged video-EEG and verbal and nonverbal memory tests (Rey Auditory Verbal Learning Test and Rey-Osterrieth Complex figure), with additional very delayed trials. Patients were classified according to ictal/interictal EEG findings and MTS side as left or right concordant or discordant. Thirty-nine normal individuals who underwent the same neuropsychological battery served as controls. Demographic, disease, and treatment features did not differ among groups. On the 7-day verbal memory free recall, left discordant performed significantly worse than controls and right concordant, recognized fewer words, and had more recognition errors than all other groups, including left concordant. For nonverbal memory, right discordant performed significantly worse than controls on delayed recall, and attained lower scores than other groups on immediate and 7-day recall, but this difference did not reach statistical significance. Left discordant had higher scores of memory complaints than controls and disclosed a trend toward accentuated memory impairment compared with the other groups over time. Our results suggest that contralateral electrographic involvement in uMTS was associated with more pronounced memory impairment for verbal material in left discordant patients, and to a lesser extent, for nonverbal material in right discordant patients. Left discordant group also had increased memory complaints. (PsycINFO Database Record

Carotid stiffness is associated with impairment of cognitive performance in individuals with and without type 2 diabetes. The Maastricht Study

Background and aimsThere is increasing evidence linking arterial (mainly aortic) stiffness and type 2 diabetes, a risk factor for arterial stiffness, to cognitive impairment and dementia. However, data on carotid stiffness, which may be especially relevant for cognitive performance, are scarce, and few studies have addressed the interplay between arterial stiffness, type 2 diabetes, and cognitive performance. MethodsWe studied individuals with (n = 197) and without (n = 528) type 2 diabetes, who completed a neuropsychological test battery and underwent applanation tonometry and vascular ultrasound to evaluate aortic (i.e. carotid-to-femoral pulse wave velocity) and carotid stiffness (i.e. distensibility, compliance and Young's elastic modulus). Linear regression analyses were performed and adjusted for demographics, vascular risk factors, and depression. ResultsOverall, our results showed that carotid, but not aortic, stiffness was associated with worse cognitive performance, primarily in the domains of processing speed (standardized regression coefficient for distensibility −0.083, p = 0.040; compliance −0.077, p = 0.032) and executive function and attention (distensibility −0.133, p = 0.001; compliance −0.090, p = 0.015; Young's elastic modulus −0.081, p = 0.027). These associations did not differ by diabetes status. The differences in cognitive performance between individuals with and without type 2 diabetes (mean difference in domain scores relative to those without diabetes for free recall memory −0.23, processing speed −0.19, executive function and attention −0.23; all p ≤ 0.009 and adjusted for demographics, traditional vascular risk factors, and depression) were not substantially altered after additional adjustment for carotid stiffness. ConclusionsOur findings suggest that carotid stiffness is associated with cognitive performance in both individuals with and without diabetes, but does not mediate the relationship between type 2 diabetes and cognitive dysfunction.

109 - Beyond Cardiac Output: Physiological Improvement Predicts Memory Improvement Post LVAD Placement

Background:Advanced heart failure (AHF) causes multi-system dysfunction, in addition to cognitive decline. The predominant model speculates cerebral hypoperfusion places patients at risk for cognitive decline. Left Ventricular Assist Device (LVAD) implant is growing exponentially as a treatment modality for AHF. Despite reports of improvement in multiple body systems following LVAD placement, including cognition, research examining physiological mechanisms impacting longitudinal outcomes of cognition is sparse. We have previously found improved cognition after LVAD implant in processing speed, verbal free recall memory, verbal recognition memory, and visual memory. Objective: We aimed to identify physiologic metrics that might correlate or predict neurologic improvement. Methods: We followed patients pre- and post-LVAD implantation (n = 17), comparing cognition and multiple physiological outcomes across time points (A: 3–6 months; B: 6–12 months; C: 2 years) for individuals using linear mixed models. Results: Cardiac output was related to improvements in verbal free recall 12 months post-implant, showing a linear relationship with regard to memory. Albumin levels also showed a linear relationship with verbal memory 12 months post-implant. Creatinine improvement predicted visual memory while improvement in sodium predicted improvement in both visual memory and verbal recognition memory. Findings expand the predominant model of improvements in cognition following LVAD placement to include related systemic physiological outcomes. Conclusion: These contribute to the limited extant research showing stable or modest improvements in cognition and provide further understanding of the physiologic mechanisms that may explain the effects of LVAD placement on neurocognition.

Positive schizotypy and negative schizotypy are associated with differential patterns of episodic memory impairment

Cognitive impairment is a hallmark of schizophrenia; however, studies have not comprehensively examined such impairments in non-clinically ascertained schizotypic young adults. The present study employed a series of measures to assess episodic memory in high positive schizotypy, high negative schizotypy, and comparison groups (each group n=25). Consistent with diminished cognitive functioning seen in negative symptom schizophrenia, the negative schizotypy group exhibited deficits on free recall, recognition, and source memory tasks. The positive schizotypy group did not demonstrate deficits on the above mentioned tasks. However, in contrast to the other groups, the positive schizotypy group showed an unexpected set-size effect on the cued-recall task. Set-size effect, which refers to the finding that words that have smaller networks of associates tend to have a memory advantage, is usually found in associative-cuing, but not cued-recall, tasks. The finding for the positive schizotypy group is consistent with heightened spreading activation and reduced executive control suggested to underlie psychotic symptoms. The findings support a multidimensional model of schizotypy and schizophrenia, and suggest that positive and negative schizotypy involve differential patterns of cognitive impairment.

The list-composition effect in memory for emotional and neutral pictures: Differential contribution of ventral and dorsal attention networks to successful encoding

The Emotional enhancement of memory (EEM) is observed in immediate free-recall memory tests when emotional and neutral stimuli are encoded and tested together (“mixed lists”), but surprisingly, not when they are encoded and tested separately (“pure lists”). Here our aim was to investigate whether the effect of list-composition (mixed versus pure lists) on the EEM is due to differential allocation of attention. We scanned participants with fMRI during encoding of semantically-related emotional (negative valence only) and neutral pictures. Analysis of memory performance data replicated previous work, demonstrating an interaction between list composition and emotional valence. In mixed lists, neural subsequent memory effects in the dorsal attention network were greater for neutral stimulus encoding, while neural subsequent memory effects for emotional stimuli were found in a region associated with the ventral attention network. These results imply that when life experiences include both emotional and neutral elements, memory for the latter is more highly correlated with neural activity representing goal-directed attention processing at encoding.