Dissociative associative-memory deficit as a function of primacy and recency effects.

Studies designed to explore memory for single items versus paired items (i.e., associative memory) in young adults show inconsistent results. Some studies report a decrease in associative recognition and others report mild-to-moderate or even a null effect. The studies often do not take into account stimuli serial position (SSP) when analyzing the locus of associative accuracy. Studies testing SSP often target memory for items, while studies targeting associative memory decline as a function of SSP are lacking. The objective of the current study is to test the separate and joint effect of SSP (experiments 1 + 2) and presentation duration (experiment 2) on memory recognition for items versus associations. We hypothesized that greater associative decline (compared to the expected decline in memory for items with similar serial location) will be observed for the material located at the end of a learning list than the material located at the beginning of a learning list. The results of the two experiments converged and confirmed our hypotheses; the greatest associative deficit was observed for associative material located at the end of the learning list (experiments 1 + 2) and for material presented for short durations (experiment 2). The interaction between SSP and presentation duration did not reach significance; however, a direct estimation of the cumulative deficit of SSP and presentation duration confirmed our hypothesis regarding greater associative deficit for recently presented items for short durations. These results highlight the importance of the joint and separate, effect of SSP and presentation duration to the study of associative memory decline.

Neurofeedback Improves Memory and Peak Alpha Frequency in Individuals with Mild Cognitive Impairment.

Mild cognitive impairment (MCI) is a syndrome characterized by a decrease in cognitive abilities, while daily function is maintained. This condition, which is associated with an increased risk for the development of Alzheimer's disease, has no known definitive treatment at present. In this open-label pilot study we explored the possible benefits of neurofeedback for subjects with MCI. Eleven participants diagnosed with MCI were trained to increase the power of their individual upper alpha band of the electroencephalogram (EEG) signal over the central parietal region. This was achieved using an EEG-based neurofeedback training protocol. Training comprised ten 30-min sessions delivered over 5 weeks. Cognitive and electroencephalographic assessments were conducted before and after training and at 30 days following the last training session. A dose-dependent increase in peak alpha frequency was observed throughout the period of training. Memory performance also improved significantly following training, and this improvement was maintained at 30-day follow-up, while peak alpha frequency returned to baseline at this evaluation. Our findings suggest that neurofeedback may improve memory performance in subjects with mild cognitive impairment, and this benefit may be maintained beyond the training period.

Proactive interference and concurrent inhibitory processes do not differentially affect item and associative recognition: Implication for the age-related associative memory deficit.

Previous studies have suggested an associative deficit hypothesis [Naveh-Benjamin, M. ( 2000 ). Adult age differences in memory performance: Tests of an associative deficit hypothesis. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170-1187] to explain age-related episodic memory declines. The hypothesis attributes part of the deficient episodic memory performance in older adults to a difficulty in creating and retrieving cohesive episodes. In this article, we further evaluate this hypothesis by testing two alternative processes that potentially mediate associative memory deficits in older adults. Four experiments are presented that assess whether failure of inhibitory processes (proactive interference in Experiments 1 and 2), and concurrent inhibition (in Experiments 3 and 4) are mediating factors in age-related associative deficits. The results suggest that creating conditions that require the operation of inhibitory processes, or that interfere with such processes, cannot simulate associative memory deficit in older adults. Instead, such results support the idea that associative memory deficits reflect a unique binding failure in older adults. This failure seems to be independent of other cognitive processes, including inhibitory and other resource-demanding processes.

Influence of electroencephalography neurofeedback training on episodic memory: a randomized, sham-controlled, double-blind study.

The relationships between memory processes and oscillatory electroencephalography (EEG) are well established. Neurofeedback training (NFT) may cause participants to better regulate their brain EEG oscillations. The present study is a double-blind sham-controlled design investigating the effect of NFT on memory. NFT included up-training upper alpha (UA) band, up-training sensory-motor rhythm (SMR) band and sham protocol. Thirty healthy adult volunteers were randomly divided into three treatment groups. NFT sessions (30 min each) took place twice weekly for a total of 10 sessions while memory testing took place pre- and post-training. The results indicate dissociation between SMR and UA NFT and different memory processes. While the SMR protocol resulted in improving automatic, item-specific and familiarity-based processes in memory, the UA protocol resulted in improved strategic and controlled recollection. The implications of the results are discussed.

Transient Adverse Side Effects During Neurofeedback Training: A Randomized, Sham-Controlled, Double Blind Study.

The benefits of clinical neurofeedback training are well known, however, its adverse side-effects are less studied. This research focuses on the transient adverse side effects of neurofeedback training via a double-blind, sham/controlled methodology. Thirty healthy undergraduate students volunteers were randomly divided into three treatment groups: increasing a modified Sensory Motor Rhythm, increasing Upper Alpha, and Sham/control group who receive a random reward. The training sessions were administered for a total of ten sessions. Questionnaires of transient adverse side effects were completed by all volunteers before each session. The results suggest that similar to most medical treatments, neurofeedback can cause transient adverse side effects. Moreover, most participants reported experiencing some side effects. The side effects can be divided into non-specific side effect, associated with the neurofeedback training in general and specific ones associated with the particular protocol. Sensory Motor Rhythm protocol seems to be the most sensitive to side effects.

Reduced corpus-callosum volume in posttraumatic stress disorder highlights the importance of interhemispheric connectivity for associative memory.

Memory deficits are a common complaint of patients with posttraumatic stress disorder (PTSD). Despite vivid trauma-related memory, previous studies report memory impairment for nontrauma-related stimuli when compared to controls, specifically in associative memory (Guez et al., 2011). Healthy individuals show hemispheric memory asymmetry with left-prefrontal lateralization of encoding and right-prefrontal lateralization of episodic retrieval, suggesting a role for interhemispheric communication in memory-related tasks (Gazzaniga, ; Ringo, Doty, Demeter, & Simard, ). Because brain magnetic resonance imaging (bMRI) studies in PTSD patients report volume changes in various regions, including white matter and corpus callosum (CC), we aimed to test the relationship between memory deficits and CC volume in PTSD patients. We probed for specific alterations in associative memory in PTSD and measured the volume of subportions within the CC employing bMRI. Our main finding was a reduction in CC white-matter volume in PTSD patients, as compared to controls, t(35) = -2.7, p = .010, that was correlated with lower associative performance (r = .76, p = .003). We propose that CC volume reduction is a substrate for the associative memory deficits found in PTSD.

Traumatic stress, active engagement and resilience in first responders and civilians in the outbreak of war.

Background: The outbreak of war in Israel on 7 October and the unique events of that day have presented unprecedented challenges to first responders (FRs), who are professionally trained to engage in providing assistance in such circumstances. Moreover, while research demonstrates the long-term psychological consequences of FRs, little is known regarding how FR's engagement in providing assistance relates to stress and resilience levels as events continue to unfold.Objective: The current study examined the relationship between traumatic stress symptoms (TSS) and resilience levels among FRs and controls during the first weeks of the Iron Swords war, while focusing on the moderating role of active engagement in providing assistance.Method: Data were collected during the first month of the Iron Swords war from 374 participants living in Southern Israel, of whom 77 (20.6%) were FRs. All participants filled out scales assessing TSS and resilience and provided relevant background information.Results: High TSS levels were associated with reduced resilience in FRs and non-FRs. Moreover, both the study group and active engagement were significant moderators for the TSS-resilience link, which was insignificant among FRs who provided assistance and for civilians who did not provide assistance. However, the TSS-resilience association remained significant for FRs who did not engage in providing assistance and for civilians who did.Conclusions: Our findings highlight the importance of examining the extent to which FRs act in line with their duties during times of adverse stress. Clinical interventions aimed towards FRs who did not engage in providing assistance are needed and should focus on the extent to which their moral values, beliefs and expectations are met, as these appear critical parameters in preserving resilience.

First responders report increased traumatic stress and reduced resilience.Active engagement moderated first responders' traumatic stress­resilience link.Findings are discussed in the context of potentially morally injurious events.

White-matter correlates of anxiety: The contribution of the corpus-callosum to the study of anxiety and stress-related disorders.

OBJECTIVES: Traumatic stress has been associated with increased risk for brain alterations and development of anxiety disorders. Studies conducted in posttraumatic patients have shown white-mater volume and diffusion alterations in the corpus-callosum. Decreased cognitive performance has been demonstrated in acute stress disorder and posttraumatic patients. However, whether cognitive alterations result from stress related neuropathology or reflect a predisposition is not known. In the current study, we examined in healthy controls, whether individual differences in anxiety are associated with those cognitive and brain alterations reported in stress related pathologies. METHODS: Twenty healthy volunteers were evaluated for anxiety using the state-trait inventory (STAI), and were tested for memory performance. Brain imaging was employed to extract volumetric and diffusion characteristics of the corpus-callosum. RESULTS: Significant correlations were found between trait anxiety and all three diffusion parameters (fractional-anisotropy, mean and radial-diffusivity). Associative-memory performance and corpus-callosum volume were also significantly correlated. CONCLUSION: We suggest that cognitive and brain alterations, as tested in the current work and reported in stress related pathologies, are present early and possibly persist throughout life. Our findings support the hypothesis that individual differences in trait anxiety predispose individuals towards negative cognitive outcomes and brain alterations, and potentially to stress related disorders.

Associative-memory deficit as a function of age and stimuli serial position.

Studies have shown associative-memory decline in aging. While the literature is inconclusive regarding the source of the deficit, some researchers argue that it is caused by impaired encoding and maintenance processes in working-memory (WM). Successful retrieval of a stimulus depends on its sequential presentation in the learning list: stimuli at the beginning or the end of the learning list benefit from higher retrieval probability. These effects are known as "primacy" and "recency" effects, respectively. In the case of the primacy-effect, stimuli at early list positions benefit from extensive rehearsal that results in enhanced consolidation and trace in long-term memory (LTM). In the case of the recency-effect, target stimuli at later serial positions are still maintained in WM and can therefore be effortlessly retrieved. Considering these effects could shed light on the involvement of WM in associative-binding. Both behavioral and neuroimaging researchers have studied associative-decline in aging. However, no work has explicitly tested age differences in memory for items versus associations as a function of stimuli serial position (SSP). In the current study, 22 younger and 22 older adults were recruited to participate in a study aimed to test the separate and joint effects of both SSP and aging on memory-recognition of items and associations. In the task used, retrieval was manipulated for SSP (beginning/middle/end of the list) and item/associations recognition modes. We hypothesized that greater associative-decline will be observed in older adults, specifically for recently presented material. The results showed that both groups presented a significant associative-deficit at the recency positions; this decrease was additive and did not correspond to the expected interaction effect. Further analysis showed that the source of associative-memory decline for stimuli at recency position in older adults resulted from an increase in false-alarm (FA) rates. These results support the involvement of WM-binding impairment in aging.

Traumatic stress is linked to a deficit in associative episodic memory.

Individuals with posttraumatic stress disorder (PTSD) are haunted by persistent memories of the trauma, but ironically are impaired in memories of daily life. The current set of 4 experiments compared new learning and memory of emotionally neutral content in 2 groups of patients and aged- and education-matched controls: 20 patients diagnosed with chronic posttraumatic stress disorder (C-PTSD) and 20 patients diagnosed with acute stress disorder (ASD). In all experiments, participants studied a list of stimuli pairs (words or pictures) and were then tested for their memory of the items, or for the association between items in each pair. Results indicated that both types of patients showed associative memory impairment compared to a control group, although their item memory performance was relatively intact. Potential mechanisms underlying such associative memory deficits in posttraumatic patients are discussed.

A simulation of older adults' associative memory deficit using structural process interference in young adults.

Associative memory deficit underlies a part of older adults' deficient episodic memory due to the reduced ability to bind units of information. In this article we further assess the mechanism underlying this deficit, by assessing the degree to which we can model it in young adults under conditions of divided attention. We shall describe two experiments in this paper; these experiments investigate item and associative recognition in young adults under full- or divided-attention conditions. The secondary tasks employed were N-back like (NBL), which serves as a working memory updating task, and parity judgement and visuospatial (VS) tasks, which serve as non-working memory tasks. The results of both experiments show that only the NBL specifically affected associative recognition, while the other tasks affected item and associative memory to the same degree, indicating a general resource competition. These results presented a convergence of evidence for the associative deficit in older adults by modelling it in young adults.

Mild Cognitive Impairment and Neurofeedback: A Randomized Controlled Trial.

Background and Objectives: Mild cognitive impairment (MCI) is often a precursor of dementia, and in particular of Alzheimer's Disease (AD) which is the most common cause of dementia. Individuals with amnestic MCI are several-fold more likely to develop AD than the general population. Therefore, MCI comprises a well-detectable, early stage time-point for therapeutic intervention and strategic prevention. Based on common electroencephalographical (EEG) pattern changes seen in individuals with MCI, we postulated that EEG-based neurofeedback could help improve the memory performance of patients with MCI. Memory performance is of particular importance in these patients, since memory decline is the most prominent symptom in most patients with MCI, and is the most predictive symptom for cognitive deterioration and the development of AD. Methods: In order to improve the memory performance of patients with MCI we used a system of EEG-based neurofeedback in an attempt to reverse alterations of the EEG that are known to be common in patients with MCI. Our protocol comprised the provision of positive feedback in order to enhance the activity level of the upper alpha band. Participants were divided to two groups receiving either neurofeedback training to enhance the upper alpha frequency (Experimental group) or random feedbacks (Sham group) Results: We witnessed a significant improvement in memory performance in subjects in the experimental group compared to those in the sham group. This improvement was maintained for at least 1 month. Conclusions: Neurofeedback may be a promising and affordable novel approach for treating the decline in memory witnessed in patients with MCI.

Reduced HbA1c levels in type 2 diabetes patients: An interaction between a pedagogical format for students and psycho-educational intervention for patients.

In this prospective study we compared Hemoglobin A1c (HbA1c) levels in T2DM (Type 2 diabetes) patients who received psycho-educational intervention vs. usual care. Intervention was provided by pharmaceutics students, and accompanied by an academic course. We further examined the effect of the pedagogical format by which students were taught on HbA1c levels of the patients. The format of the academic course varied: the simultaneous format included theoretical, clinical, and practical themes taught within each lesson; whereas in the non-simultaneous format, theoretical themes were taught during the first several lessons, followed by practical skills taught in the following ones. T2DM patients (n = 171) were recruited through 10 primary care clinics. The inclusion criterion was patients with uncontrolled type 2 diabetes (HbA1c > 7%). Patients were randomly allocated to a training or control group. Pharmaceutics students (n = 85) in their fourth year participated in an academic course and were randomly allocated to a simultaneous vs. non-simultaneous pedagogical format. The interaction effect between intervention type and pedagogical format was significant. Only patients who participated in the training group consisting of students who participated in the simultaneous course format showed improvement on their HbA1c levels. Implications on patients' outcome and suggestions for future studies are discussed.

The effects of divided attention on encoding processes in memory: mapping the locus of interference.

Despite the detrimental effects of divided attention at encoding on later memory performance, results described in the literature do not unequivocally specify which processes are interrupted during encoding by participants' occupation with a concurrent task. Using a processing analysis framework where the encoding process is viewed as a multiphase mental activity, the current research investigated this issue using a new differential temporal interference paradigm where the study phase of single words was interrupted at different temporal segments. In two experiments, we used performance on both memory and online choice reaction time tasks to assess whether such differential interference would produce different degrees of reduction in participants' later memory performance, as well as changes in the attentional resources required to execute each of the encoding phases. Measures of memory and concurrent task performance in the two experiments converged on similar patterns, showing that all phases of encoding are affected by the concurrent task. However, the initial encoding phase, which is tentatively associated with the initial registration of information, seems especially vulnerable to interference.

A picture is worth a thousand words? Not when it comes to associative memory of older adults.

Properties of the binding mechanism in associative recognition were studied by examining the influence of the pictorial superiority effect on the age-related associative deficit. The informative aspect of associative recognition is the recollection of the pairing. Previous findings indicate that recollection is susceptible to aging and that pictorial presentation can enhance recollection and facilitate associative recognition. Pictorial presentation was found to facilitate item recognition by both young and older adults, associative recognition by young adults, but not associative recognition by older adults. Our findings support the hypothesis that the binding mechanism in associative recognition is content independent. Theoretical implications are discussed.

The Effect of Trier Social Stress Test (TSST) on Item and Associative Recognition of Words and Pictures in Healthy Participants.

Psychological stress, induced by the Trier Social Stress Test (TSST), has repeatedly been shown to alter memory performance. Although factors influencing memory performance such as stimulus nature (verbal/pictorial) and emotional valence have been extensively studied, results whether stress impairs or improves memory are still inconsistent. This study aimed at exploring the effect of TSST on item versus associative memory for neutral, verbal, and pictorial stimuli. 48 healthy subjects were recruited, 24 participants were randomly assigned to the TSST group and the remaining 24 participants were assigned to the control group. Stress reactivity was measured by psychological (subjective state anxiety ratings) and physiological (Galvanic skin response recording) measurements. Subjects performed an item-association memory task for both stimulus types (words, pictures) simultaneously, before, and after the stress/non-stress manipulation. The results showed that memory recognition for pictorial stimuli was higher than for verbal stimuli. Memory for both words and pictures was impaired following TSST; while the source for this impairment was specific to associative recognition in pictures, a more general deficit was observed for verbal material, as expressed in decreased recognition for both items and associations following TSST. Response latency analysis indicated that the TSST manipulation decreased response time but at the cost of memory accuracy. We conclude that stress does not uniformly affect memory; rather it interacts with the task's cognitive load and stimulus type. Applying the current study results to patients diagnosed with disorders associated with traumatic stress, our findings in healthy subjects under acute stress provide further support for our assertion that patients' impaired memory originates in poor recollection processing following depletion of attentional resources.

Breakdown of Inter-Hemispheric Connectivity Is Associated with Posttraumatic Symptomatology and Memory Impairment.

Altered brain anatomy in specific gray-matter regions has been shown in patients with posttraumatic stress disorder (PTSD). Recently, white-matter tracts have become a focus of research in PTSD. The corpus callosum (CC) is the principal white-matter fiber bundle, crucial in relaying sensory, motor and cognitive information between hemispheres. Alterations in CC fibers have been reported in PTSD and might be assumed to underlie substantial behavioral and cognitive sequelae; however most diffusion tensor imaging (DTI) studies in adult-onset PTSD failed to address the clinical correlates between imaging and PTSD symptoms severity, behavioral manifestation and cognitive functions. In the current study we examined (a) to what extent microstructural integrity of the CC is associated with memory performance and (b) whether imaging and cognitive parameters are associated with PTSD symptom severity. DTI data were obtained and fractional anisotropy (FA) values were computed for 16 patients and 14 controls. PTSD symptom severity was assessed by employing the clinician administered PTSD scale (CAPS) and memory was tested using a task probing item and associative memory for words and pictures. Significant correlations were found between PTSD symptoms severity, memory accuracy and reaction-time to CC FA values in the PTSD group. This study demonstrates meaningful clinical and cognitive correlates of microstructural connectivity. These results have implications for diagnostic tools and future studies aimed at identifying individuals at risk for PTSD.

Divided attention in younger and older adults: effects of strategy and relatedness on memory performance and secondary task costs.

Divided attention at encoding leads to a significant decline in memory performance, whereas divided attention during retrieval has relatively little effect; nevertheless, retrieval carries significant secondary task costs, especially for older adults. The authors further investigated the effects of divided attention in younger and older adults by using a cued-recall task and by measuring retrieval accuracy, retrieval latency, and the temporal distribution of attentional costs at encoding and retrieval. An age-related memory deficit was reduced by pair relatedness, whereas strategy instructions benefited both age groups equally. Attentional costs were greater for retrieval than for encoding, especially for older adults. These findings are interpreted in light of notions of an age-related associative deficit (M. Naveh-Benjamin, 2000) and age-related differences in the use of self-initiated activities and environmental support (F. I. M. Craik, 1983, 1986).

Negative Emotional Arousal Impairs Associative Memory Performance for Emotionally Neutral Content in Healthy Participants.

The effect of emotional arousal on memory presents a complex pattern with previous studies reporting conflicting results of both improved and reduced memory performance following arousal manipulations. In this study we further tested the effect of negative emotional arousal (NEA) on individual-item recognition and associative recognition of neutral stimuli in healthy participants, and hypothesized that NEA will particularly impair associative memory performance. The current study consists of two experiments; in both, participants studied a list of word-pairs and were then tested for items (items recognition test), and for associations (associative recognition test). In the first experiment, the arousal manipulation was induced by flashing emotionally-negative or neutral pictures between study-pairs while in the second experiment arousal was induced by presenting emotionally-negative or neutral pictures between lists. The results of the two experiments converged and supported an associative memory deficit observed under NEA conditions. We suggest that NEA is associated with an altered ability to bind one stimulus to another as a result of impaired recollection, resulting in poorer associative memory performance. The current study findings may contribute to the understanding of the mechanism underlying memory impairments reported in disorders associated with traumatic stress.

Dissociative Reality and Dissociative Being in Therapy for Post traumatic Patients.

Post traumatic patients experience a wide range of symptoms, some of them existential in nature which we term "dissociative being." Many varied psychotherapeutic approaches are available for the treatment of post traumatic patients. Nevertheless, in view of this disorder's complexity, therapists face shortcomings when employing each of these therapeutic interventions. In order to understand this, we posit the principle we call "dissociative reality" for the treatment of trauma survivors. Our proposed method "speaks the patient's own language," harnessing dissociative elements to help individuals recall, re-enact and integrate traumatic experiences, where words are insufficient, while still upholding reality. We believe that this may be seen as an effective part of the therapeutic dialogue, and suggest that therapists may consider supplementing this approach in their treatment "toolkit" for patients with post traumatic stress and other trauma related disorders, irrespective of their declared therapeutic approach.