Intra- and inter-item associations doubly dissociate the electrophysiological correlates of familiarity and recollection

Single-process models of recognition memory posit that recognizing is based on a unidimensional value of global memory strength. By contrast, dual-process models propose the existence of two independent processes subserving the explicit recognition of previously encountered episodes, namely "familiarity" and "recollection." Familiarity represents a noncontextual form of recognition that may only support the retrieval of associative information when the to-be-associated information can be unitized, such as when two photographs depicting the same person are memorized (intra-item associations). Conversely, recollection enables retrieving associations between arbitrarily linked information, such as associations between photographs of different persons (inter-item associations). By measuring event-related brain potentials (ERPs), we obtained a double dissociation of familiarity and recollection that strongly favors dual-process accounts of recognition memory: the electrophysiological correlate of familiarity was significantly larger for intra- than for inter-item associations. Conversely, the electrophysiological correlate of recollection was significantly larger for inter- than for intra-item associations.     

Perirhinal cortex supports encoding and familiarity-based recognition of novel associations

Results from imaging and lesion studies of item recognition memory have suggested that the hippocampus supports memory for the arbitrary associations that form the basis of episodic recollection, whereas the perirhinal cortex (PRc) supports familiarity for individual items. This view has been challenged, however, by findings showing that PRc may contribute to associative recognition, a task thought to measure relational or recollective memory. Here, using functional magnetic resonance imaging, we demonstrate that PRc activity is increased when pairs of items are processed as a single configuration or unit and that this activity predicts subsequent familiarity-based associative memory. These results explain the discrepancy in the literature by showing that novel associations can be encoded in a unitized manner, thereby allowing PRc to support associative recognition based on familiarity.     

Sleep supports selective retention of associative memories based on relevance for future utilization

An outstanding question is whether memory consolidation occurs passively or involves active processes that selectively stabilize memories based on future utility. Here, we differentially modulated the expected future relevance of two sets of picture-location associations after learning. Participants first studied two sets of picture-location associations. After a baseline memory test, they were instructed that only one set of associations would be retested after a 14-hour delay. For half of the participants, this test-retest delay contained a night of sleep; for the other half the delay included a normal working day. At retest, participants were re-instructed and against their expectations tested on both sets of associations. Our results show that post-learning instruction about subsequent relevance selectively improves memory retention for specific associative memories. This effect was sleep-dependent; it was present only in the group of subjects for which the test-retest delay contained sleep. Moreover, time spent asleep for participants in this sleep group correlated with retention of relevant but not irrelevant associations; participants who slept longer forgot fewer associations from the relevant category. In contrast, participants that did not sleep forgot more relevant than irrelevant associations across the test-retest delay. In summary, our results indicate that it is possible to modulate the retention of selected memories after learning with simple verbal instructions on their future relevance. The finding that this effect depends on sleep demonstrates this state's active role in memory consolidation and may have utility for educational settings.     

Developing a Molecular Roadmap of Drug-Food Interactions

Recent research has demonstrated that consumption of food -especially fruits and vegetables- can alter the effects of drugs by interfering either with their pharmacokinetic or pharmacodynamic processes. Despite the recognition of such drug-food associations as an important element for successful therapeutic interventions, a systematic approach for identifying, predicting and preventing potential interactions between food and marketed or novel drugs is not yet available. The overall objective of this work was to sketch a comprehensive picture of the interference of ∼ 4,000 dietary components present in ∼1800 plant-based foods with the pharmacokinetics and pharmacodynamics processes of medicine, with the purpose of elucidating the molecular mechanisms involved. By employing a systems chemical biology approach that integrates data from the scientific literature and online databases, we gained a global view of the associations between diet and dietary molecules with drug targets, metabolic enzymes, drug transporters and carriers currently deposited in DrugBank. Moreover, we identified disease areas and drug targets that are most prone to the negative effects of drug-food interactions, showcasing a platform for making recommendations in relation to foods that should be avoided under certain medications. Lastly, by investigating the correlation of gene expression signatures of foods and drugs we were able to generate a completely novel drug-diet interactome map.     

Wieviorka's view on multiculturalism: a critique

Like any other society France is increasingly diversified culturally and in terms of collective identities. Clearly it is a multicultural, multi-identificational society, but it is not often willing to discuss openly the changes needed to accommodate its diversity and its de facto multicultural character. Michel Wieviorka has been courageous in trying to launch this crucial debate. In France his work is often appreciated but it is also often held to be ‘politically incorrect’ precisely because it questions the validity of the French republican model and its adequacy for the deep social changes at work in French society, and also because it raises the issue of the necessity of building a French multiculturalism. In this article the most important insights of Wieviorka's perspectives on multiculturalism are presented and some of the problems it implies are discussed.     

雌性布氏田鼠对不同共居时间雄性气味的识别与记忆

啮齿动物的社会识别包括对化学信号的辨别、学习和记忆。田鼠属动物雌雄成年个体共居一定时间后,可以利用气味信号来识别配偶。本研究将成年雌雄布氏田鼠配对饲养12 h、18 h、24 h,确认发生交配行为形成配对关系后,分开单独饲养6 h,取配偶雄鼠和陌生雄鼠巢垫物作为个体气味,在气味选择箱中观察雌鼠对配偶雄鼠和陌生雄鼠气味信号的探究和选择行为,从而探讨不同共居时间雌性布氏田鼠对配偶气味信号的识别与记忆的影响。研究结果表明:共居时间影响雌性布氏田鼠对配偶气味的识别与记忆;共居时间越长,雌鼠在气味探究和选择时间上对配偶气味偏好越明显;共居24 h 后,雌性布氏田鼠能够识别出配偶雄鼠的气味信号并形成记忆,这样的记忆维持时间至少是6 h。     

Scalable PGAS collective operations in NUMA clusters

The increasing number of cores per processor is turning manycore-based systems in pervasive. This involves dealing with multiple levels of memory in non uniform memory access (NUMA) systems and processor cores hierarchies, accessible via complex interconnects in order to dispatch the increasing amount of data required by the processing elements. The key for efficient and scalable provision of data is the use of collective communication operations that minimize the impact of bottlenecks. Leveraging one sided communications becomes more important in these systems, to avoid unnecessary synchronization between pairs of processes in collective operations implemented in terms of two sided point to point functions. This work proposes a series of algorithms that provide a good performance and scalability in collective operations, based on the use of hierarchical trees, overlapping one-sided communications, message pipelining and the available NUMA binding features. An implementation has been developed for Unified Parallel C, a Partitioned Global Address Space language, which presents a shared memory view across the nodes for programmability, while keeping private memory regions for performance. The performance evaluation of the proposed implementation, conducted on five representative systems (JuRoPA, JUDGE, Finis Terrae, SVG and Superdome), has shown generally good performance and scalability, even outperforming MPI in some cases, which confirms the suitability of the developed algorithms for manycore architectures.     

Perception of the Emotional Speech Component by Stuttering Children Associated with Noise: Communication II. Analysis of the Temporal Characteristics of the Recognition of Different Emotions

The reaction time for the recognition of different emotions in speech against a background of noise in stutterers and normally speaking children between the ages of 7 to 17 years was studied. The specific differences between these two types of subjects in processing the emotional speech component were more markedly pronounced in terms of the reaction time than the effectiveness of recognition. An increase in the noise level decreases the effectiveness of recognition and increases the reaction time; however, the stutterers do not show a statistically significant lengthening of the reaction time. With increasing age, the recognition time of the emotion type in both groups of subjects is shortened, although sex-related differences may be observed: only in stuttering girls is the difference in the recognition time between the junior and senior groups great enough and comparable to that of normally speaking girls. The stuttering children (SC) were found to have significantly shorter recognition times of the emotion types than their normally speaking counterparts. In this connection, the hypothesis about the specific features of processing the acoustic signal in the sensory memory of SC was advanced. These results suggest that the specific features of the processes occurring in the memory subsystems of stutterers may be one of the causes of stuttering, along with the differences in interhemispheric relations found in previous works.     

Age-Related Decline in Associative Learning in Healthy Chinese Adults

Paired associates learning (PAL) has been widely used in aging-related research, suggesting an age-related decline in associative learning. However, there are several cognitive processes (attention, spatial and recognition memory, strategy, and associative learning) involved in PAL. It is unclear which component contributes to the decline in PAL performance associated with age effects. The present study determines whether age effects on associative learning are independent of other cognitive processes involved in PAL. Using a validated computerized cognitive program (CANTAB), we examined cognitive performance of associative learning, spatial and recognition memory, attention and strategy use in 184 Singaporean Chinese adults aged from 21 to 80 years old. Linear regression revealed significant age-related decline in associative learning, spatial and recognition memory, and the level of strategy use. This age-related decline in associative learning remains even after adjusting for attention, spatial and recognition memory, and strategy use. These results show that age effects on associative learning are independent of other cognitive processes involved in PAL.     

Nations and Tribes ‘Within’: Emerging Aboriginal ‘Nationalisms’ in Katherine

Throughout Australia, many Aboriginal responses to the legislative and administrative pressures of the native title regime have been couched in a nation‐building idiom expressed through legally incorporated Aboriginal associations. The membership criteria of these umbrella associations are often derived from definitions of the ‘tribe’ or ‘language group’. Yet, in a kind of Balkanisation, those who see themselves as marginalised to positions of uncertainty on the peripheries of the nation often seek to establish their own independent corporations on the basis of exclusive ties to specific areas of land within it, in search of greater recognition and in competition for scarce resources. In Katherine, in the Northern Territory of Australia, the administrative and legislative gaze of the State, particularly the Aboriginal Land Rights (Northern Territory) Act 1976, brought into focus a Jawoyn ‘tribe’, soon to express itself in the idiom of nationhood, closely followed by a Wardaman ‘tribe’ and ‘nation’. More recently, a native title gaze has now brought into focus ‘new’ configurations of kindred clusters, apparently located on the ‘peripheries' of the Jawoyn and Wardaman nations, and named and valued them as Dagoman. This paper discusses the processes associated with an emerging, but seemingly already fragmenting, Dagoman nation. It argues that divergent and changing Aboriginal subjectivities disrupt what might be seen as mimetic processes as Aboriginal people employ strategies of transforming essentialist representations of their collective selves in changing conditions of possibility.     

Recognition memory: what are the roles of the perirhinal cortex and hippocampus?

The hallmark of medial temporal lobe amnesia is a loss of episodic memory such that patients fail to remember new events that are set in an autobiographical context (an episode). A further symptom is a loss of recognition memory. The relationship between these two features has recently become contentious. Here, we focus on the central issue in this dispute--the relative contributions of the hippocampus and the perirhinal cortex to recognition memory. A resolution is vital not only for uncovering the neural substrates of these key aspects of memory, but also for understanding the processes disrupted in medial temporal lobe amnesia and the validity of animal models of this syndrome.     

Cognitive association formation in human memory revealed by spatiotemporal brain imaging

Cognitive theory posits association by juxtaposition or by fusion. We employed the measurement of event-related brain potentials (ERPs) to a concept fusion task in order to explore memory encoding of these two types of associations between word pairs, followed by a memory test for original pair order. Encoding processes were isolated by subtracting fusion task ERPs corresponding to pairs later retrieved quickly from ERPs corresponding to pairs later retrieved slowly, separately for pairs fused successfully and unsuccessfully (i.e., juxtaposed). Analyses revealed that the encoding of these two types of associations yields different ERP voltage polarities, scalp topographies, and brain sources extending over the entire time course of processing.     

Hippocampus and neocortex: recognition and spatial memory

Recognition and spatial memory are typically associated with the perirhinal cortex and hippocampal formation, respectively. Solely focusing on these structures for these specific mnemonic functions may, however, be limiting progress in the field. The distinction between these subdivisions of memory is becoming less defined as, for example, hippocampal cells traditionally considered to encode locations also encode place-object associations. There is increasing evidence for the involvement of overlapping networks of brain structures for aspects of both spatial and recognition memory. Future models of spatial and recognition memory will have to extend beyond the hippocampus and perirhinal cortex to incorporate a wider network of cortical and subcortical structures.     

Long-term memory of individual identity in ant queens

Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.     

Retrieval Intention Modulates the Effects of Directed Forgetting Instructions on Recollection

The neurocognitive basis of memory retrieval is often examined by investigating brain potential old/new effects, which are differences in brain activity between successfully remembered repeated stimuli and correctly rejected new stimuli in a recognition test. In this study, we combined analyses of old/new effects for words with an item-method directed-forgetting manipulation in order to isolate differences between the retrieval processes elicited by words that participants were initially instructed to commit to memory and those that participants were initially instructed to forget. We compared old/new effects elicited by to-be-forgotten (TBF) words with those elicited by to-be-remembered (TBR) words in both an explicit-memory test (a recognition test) and an implicit-memory test (a lexical-decision test). Behavioral results showed clear directed forgetting effects in the recognition test, but not in the lexical decision test. Mirroring the behavioral findings, analyses of brain potentials showed evidence of directed forgetting only in the recognition test. In this test, potentials from 450–650 ms (P600 old/new effects) were more positive for TBR relative to TBF words. By contrast, P600 effects evident during the lexical-decision test did not differ in magnitude between TBR and TBF items. When taken in the context of prior studies that have linked similar parietal old/new effects to the recollection of episodic information, these data suggest that directed-forgetting effects manifest primarily in greater episodic retrieval by TBR than TBF items, and that retrieval intention may be important for these directed-forgetting effects to occur.     

Recognizing faces

Face recognition is an area where research has increased considerably in recent years, yet theoretical progress has been slow. Here it is argued that by considering the perception and recognition of familiar faces, as well as episodic memory for unfamiliar faces, a functional framework for face recognition can be developed. Experiments using faces, that include tasks analogous to 'visual search' and 'lexical decision' are described, and the processes in operation are compared with those occurring in word recognition. The results allow us to distinguish a number of possible subcomponents for a functional model of face recognition.     

Swarms of particle agents with harmonic interactions

Summary Agent-based modeling is a powerful methodology to describe the occurence of complex behavior in biological systems. The interaction of a large number of individuals (agents) may for example lead to the emergence of new forms of collective motion. In this paper, we investigate a particle-based approach to the coherent motion of a swarm with parabolic (i. e. harmonic) interactions between the agents. It is based on generalized Langevin equations for the particle agents, which take into account (i) energetic conditions for active motion, (ii) linear attractive forces between each two agents. The complex collective motion observed can be explained as the result of these different influences: the active motion of the agents, which is driven by the energy-take up, would eventually lead to a spatial dispersion of the swarm, while the mutual interaction of the agents results in a tendency of spatial concentration. In addition to particle-based computer simulations, we also provide a mathematical framework for investigating the collective dynamics. Dedicated to the memory of Michael Conrad     

The Role of Anterior Nuclei of the Thalamus: A Subcortical Gate in Memory Processing: An Intracerebral Recording Study

Objective

To study the involvement of the anterior nuclei of the thalamus (ANT) as compared to the involvement of the hippocampus in the processes of encoding and recognition during visual and verbal memory tasks.

Methods

We studied intracerebral recordings in patients with pharmacoresistent epilepsy who underwent deep brain stimulation (DBS) of the ANT with depth electrodes implanted bilaterally in the ANT and compared the results with epilepsy surgery candidates with depth electrodes implanted bilaterally in the hippocampus. We recorded the event-related potentials (ERPs) elicited by the visual and verbal memory encoding and recognition tasks.

Results

P300-like potentials were recorded in the hippocampus by visual and verbal memory encoding and recognition tasks and in the ANT by the visual encoding and visual and verbal recognition tasks. No significant ERPs were recorded during the verbal encoding task in the ANT. In the visual and verbal recognition tasks, the P300-like potentials in the ANT preceded the P300-like potentials in the hippocampus.

Conclusions

The ANT is a structure in the memory pathway that processes memory information before the hippocampus. We suggest that the ANT has a specific role in memory processes, especially memory recognition, and that memory disturbance should be considered in patients with ANT-DBS and in patients with ANT lesions.ANT is well positioned to serve as a subcortical gate for memory processing in cortical structures.     

Multicultural society and everyday cultural racism: second generation of Ethiopian Jews in Israel's ‘crisis of modernization’

Abstract

The core of this article sets out to examine the extent to which a multicultural society can prevent cultural racism, which, like multiculturalism, is by definition based on a culture of diversity and separation. The ‘first modernity’ was organized along national lines, with a centralist state that opted to create an essentialist and uncontested national identity. Immigrants, especially those who came from ‘third world’ countries, were expected to undergo a process of assimilation, and to integrate into the dominant culture by relinquishing their particular past and tradition. Multiculturalism, which emerged historically as a criticism of that perspective, aims at creating a kaleidoscope of associations and cultural communities, which inevitably presents a challenge to the one ‘truth’ of the nation-state with the argument that this ‘truth’ favours some groups over others. Within the multicultural model, identity politics of various groups is perceived as a means to achieve recognition, acceptance, respect and even public affirmation of differences. However, do multicultural society and identity-related differences provide a solution to cultural racism as well?

Investigating the second generation of the Ethiopian Jews, who migrated to Israel during its transformation from ethno-national republicanism to a neo-liberal, multicultural society, can help answer this question. By presenting their patterns of association, character of protest activities and the newly formed hybrid identity that Ethiopian youth have developed as a means to liberate themselves from a discriminating reality, and by examining the Others’ reaction to that challenge, this article uncovers certain mechanisms and methods of action through which a multicultural society, having a thin and mild version of multiculturalism, does not diminish cultural racism, particularly its everyday non-institutional version, but in fact augments it.