An empirical and computational investigation of perceiving and remembering event temporal relations

Events have beginnings, ends, and often overlap in time. A major question is how perceivers come to parse a stream of multimodal information into meaningful units and how different event boundaries may vary event processing. This work investigates the roles of these three types of event boundaries in constructing event temporal relations. Predictions were made based on how people would err according to the beginning state, end state, and overlap heuristic hypotheses. Participants viewed animated events that include all the logical possibilities of event temporal relations, and then made temporal relation judgments. The results showed that people make use of the overlap between events and take into account the ends and beginnings, but they weight ends more than beginnings. Neural network simulations showed a self-organized distinction when learning temporal relations between events with overlap versus those without.     

独生与非独生儿童认知发展的比较研究(广州市)

为了研究中国独生子女政策可能造成的独生和非独生儿童的认知能力的差别,分别在广州七所小学一年级和五年级中选择了146名和171名独生与非独生儿童。用11项认知能力测验对这些儿童进行测查。一年级独生儿童在言语记忆和一般常识项目上的成绩优于非独生儿童。研究认为,一年级独生儿童在与一般认知能力有关的项目上具有优势。而五年级的独生儿童在认知作业成绩上,没有表现出显著性的优势。另外,独生男童在一般常识方面优于独生女童。作者用独生儿童受到较大的父母关注和投资来解释一年级独生对非独生儿童在认知方面的优势。随着儿童的自然成熟和学业教育,两者之间的差距会逐渐缩小,从而使五年级独生儿童未能在认知方面表现出明显的优势。     

Lifelong reductions of PKMζ in ventral hippocampus of nonhuman primates exposed to early-life adversity due to unpredictable maternal care

Protein kinase Mζ (PKMζ) maintains long-term potentiation (LTP) and long-term memory through persistent increases in kinase expression. Early-life adversity is a precursor to adult mood and anxiety disorders, in part, through persistent disruption of emotional memory throughout life. Here we subjected 10- to 16-wk-old male bonnet macaques to adversity by a maternal variable-foraging demand paradigm. We then examined PKMζ expression in their ventral hippocampi as 7- to 12-yr-old adults. Quantitative immunohistochemistry reveals decreased PKMζ in dentate gyrus, CA1, and subiculum of subjects who had experienced early-life adversity due to the unpredictability of maternal care. Adult animals with persistent decrements of PKMζ in ventral hippocampus express timid rather than confrontational responses to a human intruder. Persistent down-regulation of PKMζ in the ventral hippocampus might reduce the capacity for emotional memory maintenance and contribute to the long-lasting emotional effects of early-life adversity.

Early-life adversity is associated with an increased vulnerability to stress-related disorders that is maintained into adulthood, suggesting a very long-lived effect on emotional memory by the early-life event (Coplan et al. 1996). Although several structural and neurochemical sequelae of early-life adversity have been reported (Teicher et al. 2003; Jackowski et al. 2011), the direct effects of early-life adversity on the molecular substrates maintaining long-term memory storage have not been explored.Accumulating evidence supports a crucial role for the autonomously active, atypical protein kinase C (PKC) isoform protein kinase Mζ (PKMζ) in maintaining synaptic long-term potentiation (LTP), a putative physical substrate for memory, and long-term memory storage (Ling et al. 2002; Pastalkova et al. 2006; Glanzman 2013; Sacktor and Fenton 2018). The autonomous activity of PKMζ is due to its unusual structure that differs from other PKC isoforms (Sacktor et al. 1993). Most PKCs consist of two domains: a catalytic domain and an autoinhibitory regulatory domain that suppresses the catalytic domain. Therefore, most PKCs are inactive until second messengers bind to the regulatory domain and induce a conformational change that releases the autoinhibition. Because second messengers that activate PKCs such as Ca²⁺ or diacylglycerol have short half-lives, most PKCs are only transiently activated.PKMζ, in contrast, consists of an independent PKCζ catalytic domain, and the absence of an autoinhibitory regulatory domain results in autonomous and thus persistent activity once the kinase is synthesized. PKMζ mRNA is transcribed from an internal promoter within the PKCζ/PKMζ gene that is active only in neural tissue (Hernandez et al. 2003). The mRNA is translationally repressed and transported to dendrites of neurons (Muslimov et al. 2004). High-frequency afferent synaptic activity during LTP induction or learning derepresses PKMζ mRNA translation, triggering new synthesis of PKMζ protein (Osten et al. 1996; Hernandez et al. 2003; Tsokas et al. 2016; Hsieh et al. 2017).Once increased, the steady-state amount of PKMζ remains elevated during LTP or long-term memory maintenance. Recent work with quantitative immunohistochemistry (IHC) shows that spatial conditioning induces persistent increases of PKMζ in somatic and selective dendritic compartments of dorsal hippocampal CA1 pyramidal cells that can last at least 1 mo (Hsieh et al. 2021). The persistent increases are preferentially expressed in CA1 pyramidal cells that were activated during the formation of the memory, specifically at the termination zone of the Schaffer collateral/commissural inputs from subfield CA3. In contrast, persistent PKMζ increases are not evident in stratum lacunosum-moleculare, the termination zone that originates in entorhinal cortex that nonetheless is capable of expressing PKMζ. Postsynaptic domain-specific PKMζ expression patterns hint at distinct circuit-specific modifications of cortical–hippocampal synaptic function by maturational and experiential factors.Persistent changes in PKMζ expression are also associated with changes in the capacity for learning and memory across the life span of animals. Decreased memory ability in aged rats is associated with decreased training-induced, persistent PKMζ expression in prelimbic cortex, and increases in PKMζ are crucial for the cognition-enhancing effects of environmental enrichment in the aged animals (Chen et al. 2016). Hara et al. extended the connection between PKMζ and cognitive function to nonhuman primates (NHPs), showing that levels of PKMζ expression in dentate gyrus (DG) axospinous synapses correlate with successful performance on cognitive tasks in young and aged monkeys (Hara et al. 2012). These studies suggest that persistent down-regulation of PKMζ may comprise an important pathophysiological mechanism for cognitive impairment.Here we used a validated NHP model of early-life adversity, maternal variable-foraging demand (VFD), to explore the links between adversity in infancy and PKMζ expression in adulthood (Coplan et al. 1996; Jackowski et al. 2011). Previous studies of the VFD paradigm have revealed that both infants and their mothers exposed to VFD show significant cerebrospinal fluid (CSF) elevations of the stress neuropeptide, corticotropin-releasing factor (CRF). Moreover, the magnitude of CRF change in mothers and infants are positively correlated, suggesting synchronization of maternal–infant stress responses to the VFD stressor (Coplan et al. 2005). From a behavioral standpoint, maternal social rank plays a negligible role in determining an aggregate score of maternal–infant proximity, suggesting preferential attention of mothers to their infants. During the VFD condition, maternal social rank predicts >80% of the variance of maternal–infant proximity, suggesting mothering patterns are interrupted by preferential orientations to social rank; the latter determines food accessibility (Coplan et al. 2015). Dominant females show relative increases in maternal–infant proximity, whereas subordinate females show relative reductions in maternal–infant proximity. Neither pattern of attachment ameliorates an abnormal association between CSF oxytocin concentrations and hypothalamic-pituitary-adrenal (HPA) axis activity (Coplan et al. 2015). Offspring exposed to VFD rearing assessed both as juveniles and as full adults demonstrate persistent increases in CSF CRF concentrations in comparison with controls reared under non-VFD conditions (Coplan et al. 1996, 2001).Our prior neurohistological studies pointed to the DG as a region particularly vulnerable to VFD exposure, as shown by reduced trophic signaling and neurogenesis (Jackowski et al. 2011; Perera et al. 2011; Schoenfeld et al. 2021). We therefore hypothesized that early-life adversity due to unpredictable maternal care (for brevity, subsequently referred to as “early-life adversity”) reduces the persistent expression of PKMζ within the DG of ventral intrahippocampal neurocircuitry that mediates affective memory processing (Fanselow and Dong 2010). We used PKMζ antisera validated by the lack of immunostaining in PKMζ-null mice (Hsieh et al. 2021) to examine PKMζ expression in ventral hippocampus (NHP anterior hippocampus) in both DG granule cell layer and the stratum moleculare of the suprapyramidal blade that receives direct input from entorhinal cortex, as well as other regions encompassing the hippocampal formation, including the hilus, CA3, CA1, and subiculum.To assess behavioral correlates of hippocampal PKMζ expression, we used a stress-inducing paradigm designed specifically for singly housed bonnet macaque male NHPs, which we refer to as the “human exposure response” (Jackowski et al. 2011; Hamel et al. 2017), which is a variation of the paradigm used in human exposure studies by Kalin et al. in rhesus macaques (Kalin and Shelton 1989). On exposure to a direct human presence, singly housed adult male bonnet macaques react with a dichotomy of responses—confrontational versus timid (see the Materials and Methods) (Jackowski et al. 2011). In our macaque colony, groups of fully adult males are necessarily housed individually to prevent injury sustained during male agonistic encounters, whereas adult females and/or juveniles are safely housed in social groups. Because group housing of nursing females and/or juveniles of both sexes elicits a range of behaviors intrinsic to the species’ social repertoire (Rosenblum et al. 2001; Coplan et al. 2015) that complicates behavioral analyses to human exposure, we restricted our current study to male macaques.     

Fruitful visual search: Inhibition of return in a virtual foraging task

Inhibition of return (IOR) has long been viewed as a foraging facilitator in visual search. We investigated the contribution of IOR in a task that approximates natural foraging more closely than typical visual search tasks. Participants in a fully immersive virtual reality environment manually searched an array of leaves for a hidden piece of fruit, using a wand to select and examine each leaf location. Search was slower than in typical IOR paradigms, taking seconds instead of a few hundred milliseconds. Participants also made a speeded response when they detected a flashing leaf that either was or was not in a previously searched location. Responses were slower when the flashing leaf was in a previously searched location than when it was in an unvisited location. These results generalize IOR to an approximation of a naturalistic visual search setting and support the hypothesis that IOR can facilitate foraging. The experiment also constitutes the first use of a fully immersive virtual reality display in the study of IOR.     

Question asking and eye tracking during cognitive disequilibrium: Comprehending illustrated texts on devices when the devices break down

The PREG model of question asking assumes that questions emerge when there is cognitive disequilibrium, as in the case of contradictions, obstacles, and anomalies. Participants read illustrated texts about everyday devices (e.g., a cylinder lock) and then were placed in cognitive disequilibrium through a breakdown scenario (e.g., the key turns but the bolt does not move). The participants asked questions when given the breakdown scenario, and an eyetracker recorded their fixations. As was predicted, deep comprehenders asked better questions and fixated on device components that explained the malfunction. The eye fixations were examined before, during, and after the participants' questions in order to trace the occurrence and timing of convergence on faults, causal reasoning, and other cognitive processes.     

Source memory in Parkinson's disease

Three experiments (ns = 14 per group) are reported which investigated the ability of Parkinson patients to remember the characteristics of conditions under which a memory was acquired. In Exp. 1, subjects were required to indicate for each item in a recognition memory test whether it was spoken by Experimenter 1 or by Experimenter 2 (external-external source memory). In Exp. 2, subjects had to indicate for each item whether it was generated by themselves or by the experimenter (internal-external source memory). In Exp. 3, subjects had to judge whether an item was generated by themselves in saying or in thinking (internal-internal source memory). We found that patients with Parkinson's disease were not impaired in the previous two kinds of source memory (Exp. 1 and 2) but were impaired in internal-internal source memory (Exp. 3) relative to the age-matched control groups. In addition, both groups' performance could be improved when given distinctive cues, i.e., perceptual cues in Exp. 1 and different-domain cues in Exp. 2. These results suggest that the availability of cues was critical for Parkinson's disease in source memory. Finally, the result of Exp. 2 also showed generation effects for patients with Parkinson's disease. The generation effect refers to better memory of information by people when they had to produce it, e.g., producing associates to a word, compared with memory of information given to them.     

Muscular fitness,motor competence,and processing speed in preschool children

ABSTRACT

The aim of this study was to examine the relationship between muscular fitness and motor competence and processing speed in preschool children. Eighty-four preschool-aged children were recruited and underwent assessments for muscular fitness (muscular endurance and power), motor competence, and then participated in an auditory oddball task. The findings showed that muscular fitness and motor competence were associated with shorter reaction times after controlling for confounding factors. These findings provide tentative support for a positive association between muscular fitness and motor competence and processing speed in preschool children.

abbreviations:

Reaction time (RT); Institutional Review Board (IRB); Basic Motor Ability Test-Revised (BMAT); Body mass index (BMI); Preschool Children Fitness Programme (PCFP); Intraclass correlation coefficients (ICC); Thinking Creatively in Action and Movement test (TCAM); Inter-stimulus interval (ISI); Insulin-like growth factor 1 (IGF-1); Brain-derived neurotrophic factor (BDNF)     

基于事件的前瞻性记忆的年老化

采用类别判断任务作为正在进行任务,采用Einstein的研究范式探讨了前瞻性记忆是否随年龄的老化而出现年老化现象。结果表明,当前瞻性记忆任务和当前进行的任务要求的认知过程一致时,前瞻性记忆成绩不会随增龄下降;当前瞻性记忆任务和当前进行的任务要求的认知过程不一致时,前瞻性记忆出现了年老化现象;前瞻性记忆成绩和自由回忆成绩无显著相关     

Parallel central processing between tasks: Evidence from lateralized readiness potentials

The present dual-task study used lateralized readiness potentials (LRPs) and behavioral measures to determine whether response activation for Task 1 and Task 2 can occur in parallel. We also examined whether task similarity (known as dimensional overlap) increases parallel central processing by making it difficult to selectively activate one task set. With dimensional overlap, the behavioral data replicated previous findings of backward correspondence effects: The Task 1 response was influenced by its compatibility with the Task 2 response. This finding suggests parallel response activation. The LRP data supported this conclusion: Task 2 response activation (indexed by the LRP) began before Task 1 central operations had finished. When there was no dimensional overlap, backward correspondence effects could not be measured, but the LRP data confirmed that parallel response activation still occurred. We argue that parallel response activation does occur, perhaps due to accidental activation of Task 2 mapping rules when the intention is to selectively execute Task 1 mapping rules.