Proactive Interference Research Articles

A frequency reconfigurable antireflection metasurface for GPR

Abstract The antireflection metasurface (AM) is employed in ground penetrating radar (GPR) to mitigate the strong reflection of electromagnetic waves at the air-ground interface due to impedance mismatch. However, due to constraints imposed by the relative bandwidth (RBW) and manufacturing processes, these layers tend to exhibit excessive thickness and bulky shape, narrow RBW, and fixed functionality in a passive configuration. This paper presents a novel, dual-band, independent wideband tuning, frequency reconfigurable AM based on varactor diodes with center frequencies of 1.35 GHz and 2.60 GHz. This metasurface possesses positive properties such as a single layer, the ultrathin thickness (0.03 & 0.06λ), the wide RBW (43.3% & 27.4%) and remarkable antireflection. The aforementioned metasurface achieves the described mechanisms and features through the destructive interference theory and the combine element technique. Numerical simulation results of surface currents and electric field energy power demonstrate the antireflection property. The equivalent electromagnetic parameter retrieval results also provide equivalent impedance conditions for non-perfect antireflection. The proposed AM samples demonstrate notable stepwise frequency reconfigurable properties in free-space experiments. The imaging effect after loading this AM is significantly improved in real-world GPR ballast roadbed anomaly detection experiments. This approach provides significant research value and promising prospects across various disciplines, including the stepped-frequency GPR, microwave imaging, and interdisciplinary fields.

Involvement of neurons in the non-human primate anterior striatum in proactive inhibition.

Behaving as desired requires selecting the appropriate behavior and inhibiting the selection of inappropriate behavior. This inhibitory function involves multiple processes, such as reactive and proactive inhibition, instead of a single process. In this study, two male macaque monkeys were required to perform a task in which they had to sequentially select (accept) or refuse (reject) a choice. Neural activity was recorded from the anterior striatum, which is considered to be involved in behavioral inhibition, focusing on the distinction between proactive and reactive inhibitions. We identified neurons with significant activity changes during the rejection of bad objects. Cluster analysis revealed three distinct groups, of which only one showed increased activity during object rejection, suggesting its involvement in proactive inhibition. This activity pattern was consistent irrespective of the rejection method, indicating a role beyond saccadic suppression. Furthermore, minimal activity changes during the fixation task indicated that these neurons were not primarily involved in reactive inhibition. In conclusion, these findings suggest that the anterior striatum plays a crucial role in cognitive control and orchestrates goal-directed behavior through proactive inhibition, which may be critical in understanding the mechanisms of behavioral inhibition dysfunction that occur in patients with basal ganglia disease.Significance statement This study revealed a group of neurons in the anterior striatum that plays a crucial role in cognitive control by actively participating in the rejection of unfavorable choices. Contrary to previous belief, these neurons were involved in proactive inhibition (i.e., the process of discarding unnecessary options), instead of suppressing automatic responses, to achieve a goal. This distinction is vital for understanding the mechanisms by which the brain makes decisions and may have implications for addressing neurological disorders associated with impaired decision-making and inhibitory control. Our findings provide new insights into the neural mechanisms underlying goal-directed behavior and highlight the importance of the anterior striatum in orchestrating complex cognitive functions.

Remembering change: Interdependence between change awareness and meaningful connection in achieving proactive facilitation.

Two experiments investigated proactive facilitation (PF) or proactive interference (PI) in the recall of recently learned targets, under conditions of assessing the detection and recollection of target changes across two learning phases (with A-B/A-D word pairs). Some changes established meaningful connections across the phases; others did not. Task instructions on the subsequent cued-recall test (Experiment 1) or during Phase 2 study (Experiment 2) guided participants (university students) to monitor and report the changes. Accuracy in cued recall conditionalized on measures of change awareness replicated previous findings in establishing conditions for PF and PI. However, PF was much reduced for unconnected materials. Moreover, when change recollection failed, PI occurred even under conditions of meaningful connections (Experiment 1). Discussion emphasizes this interdependence of meaningfulness of connections and change awareness in influencing whether and how memory for earlier events affects memory for more recent ones.

The Infralimbic, but not the Prelimbic Cortex is needed for a Complex Olfactory Memory Task.

The medial prefrontal cortex (mPFC) plays a key role in memory and behavioral flexibility, and a growing body of evidence suggests that the prelimbic (PL) and infralimbic (IL) subregions contribute differently to these processes. Studies of fear conditioning and goal-directed learning suggest that the PL promotes behavioral responses and memory retrieval, while the IL inhibits them. Other studies have shown that the mPFC is engaged under conditions of high interference. This raises the possibility that the PL and IL play differing roles in resolving interference. To examine this, we first used chemogenetics (DREADDs) to suppress mPFC neuronal activity and tested subjects on a conditional discrimination task known to be sensitive to muscimol inactivation. After confirming the effectiveness of the DREADD procedures, we conducted a second experiment to examine the PL and IL roles in a high interference memory task. We trained rats on two consecutive sets of conflicting odor discrimination problems, A and B, followed by test sessions involving a mid-session switch between the problem sets. Controls repeatedly performed worse on Set A, suggesting that learning Set B inhibited the rats' ability to retrieve Set A memories (i.e. retroactive interference). PL inactivation rats performed similarly to controls. However, IL inactivation rats did not show this effect, suggesting that the IL plays a critical role in suppressing the retrieval of previously acquired memories that may interfere with retrieval of more recent memories. These results suggest that the IL plays a critical role in memory control processes needed for resolving interference.

Dorsolateral prefrontal cortex to ipsilateral primary motor cortex intercortical interactions during inhibitory control enhance response inhibition in open-skill athletes

Numerous studies have reported that long-term sports training can affect inhibitory control and induce brain functional alterations. However, the influence of environmental dynamics in sports training on inter-cortical connectivity has not been well studied. In the current study, we used twin-coil transcranial magnetic stimulation to investigate the functional connectivity between dorsolateral prefrontal cortex (DLPFC) and ipsilateral primary motor cortex (M1) during proactive and reactive inhibition in participants with sports skills in dynamic environment (open-skill experts), stable environment (closed-skill experts), and no sports skills (controls). Using a modified stop signal task, proactive inhibition was measured by the response delay effect (RDE), and reactive inhibition was measured by the stop-signal reaction time (SSRT). Intra-hemispheric DLPFC-M1 interactions and single pulse motor-evoked potentials (MEPs) were measured during the task. A stronger inhibitory effect of the DLPFC over M1 was observed during early reactive control stages compared to baseline levels. In addition, this inhibitory effect was pronounced when comparing open-skill experts to non-athlete controls, a relationship that was significantly correlated with superior reactive control performance. Furthermore, DLPFC to M1 influencing direction shifted from late proactive control to reactive control. Behavioral results also demonstrated enhanced proactive control abilities in open-skill experts relative to controls. Such enhancement may be due to the combination of environmental complexity and physical fitness in long-term skill training.

A Matter of Memory? Age-Invariant Relative Clause Disambiguation and Memory Interference in Older Adults.

Past research suggests that Working Memory plays a role in determining relative clause attachment bias. Disambiguation preferences may further depend on Processing Speed and explicit memory demands in linguistic tasks. Given that Working Memory and Processing Speed decline with age, older adults offer a way of investigating the factors underlying disambiguation preferences. Additionally, older adults might be subject to more severe similarity-based memory interference given their larger vocabularies and slower lexical access. Nevertheless, memory interference and sentence disambiguation have not been combined in studies on older adults before. We used a self-paced reading paradigm under memory load interference conditions. Older (n=30) and Younger (n=35) readers took part in the study online; reading times were recorded and measures of comprehension accuracy and load recall were collected. This setup allowed for the implicit measurement of attachment biases and memory interference effects interactively. Results show that similarity-based interference affected both age groups equally, but was more pronounced in NP2-biased structures, which took participants generally longer to read. Attachment preferences did not differ by group and were unaffected by Working Memory span. However, accuracy on recall prompts was predicted by Working Memory span in both groups. Findings of greater interference in syntactically dispreferred structures support unified processing models where parsing constraints naturally interact. The lack of age differences on our measures further aligns with research finding age-invariant implicit language processing.

Retirement through rose-colored glasses: greater positivity bias in retired relative to working older adults

Abstract Retirement has been associated with declines in memory beyond typical age-related memory decline. This may impact the ability to remember distinct events, as older adults (OA) are susceptible to interference in memory across experiences with overlapping features. Impaired hippocampal pattern separation, a computation that allows for the disambiguation of similar experiences as unique events, is thought to underlie age-related impairment in memory. Furthermore, positive experiences tend to be better remembered than neutral or negative experiences in aging. Socioemotional selectivity theory suggests that awareness of a limited remaining lifespan leads OA to prioritize emotionally fulfilling experiences, often leading to a bias towards positive information compared to negative or neutral information. However, the potential role of retirement in contributing to these age-related changes in memory has yet to be examined. Memory measures that tax hippocampal pattern separation may be more sensitive to memory impairment in retirement compared to standard memory measures. Retirement may exacerbate awareness of reduced remaining time, such that retired OA may experience a greater positivity bias in memory than their working peers. Here, we utilized an emotional memory task that taxes hippocampal pattern separation to examine memory in age-matched retired and working OA. We found that retired OA show selective impairments for memories with high interference and a greater positivity bias in memory compared to their working peers. These findings suggest that retirement may accelerate age-related memory changes, including greater susceptibility to interference as well as a bias toward remembering positive relative to neutral information.

Distortion of overlapping memories relates to arousal and anxiety.

Everyday experiences often overlap, challenging our ability to maintain distinct episodic memories. One way to resolve such interference is by exaggerating subtle differences between remembered events, a phenomenon known as memory repulsion. Here, we tested whether repulsion is influenced by emotional arousal, when resolving memory interference is perhaps most needed. We adapted an existing paradigm in which participants repeatedly studied object-face associations. Participants studied two different-colored versions of each object: a to-be-tested "target" and its not-to-be-tested "competitor" pair mate. The level of interference between target and competitor pair mates was manipulated by making the object colors either highly similar or less similar, depending on the participant group. To manipulate arousal, the competitor object-face associations were preceded by either a neutral tone or an aversive and arousing burst of white noise. Memory distortion for the color of the target objects was tested after each study round to examine whether memory distortions emerge after learning. We found that participants with greater sound-induced pupil dilations, an index of physiological arousal, showed greater memory attraction of target colors towards highly similar competitor colors. Greater memory attraction was also correlated with greater memory interference in the last round of learning. Additionally, individuals who self-reported higher trait anxiety showed greater memory attraction when one of the overlapping memories was associated with something aversive. Our findings suggest that memories of similar neutral and arousing events may blur together after repeated exposures, especially in individuals who show higher arousal responses and symptoms of anxiety.

The Association Between Plasma Amyloid-β 42/40 and Percentage of Semantic Intrusion Errors in Mild Cognitive Impairment.

Semantic intrusion errors (SIEs) are both sensitive and specific to PET amyloid-β (Aβ) burden in older adults with amnestic mild cognitive impairment (aMCI). Plasma Aβ biomarkers including the Aβ42/40 ratio using mass spectrometry are expected to become increasingly valuable in clinical settings. Plasma biomarkers are more clinically informative if linked to cognitive deficits that are salient to Alzheimer's disease (AD). This study included 119 older adults enrolled in the 1Florida Alzheimer's Disease Research Center (ADRC), 45 aMCI participants scored below the established Aβ42/40 ratio cut-off of 0.160 using the Quest AD-Detect™ assay indicating Aβ positivity (Aβ+), while 50 aMCI participants scored above this cut-off indicating Aβ negative status (Aβ-). Additionally, 24 cognitively unimpaired (CU) persons scored above the cut-off of 0.160 (Aβ-). The aMCI plasma Aβ+ group evidenced the greatest percentage of SIEs, followed by the aMCI Aβ-. The CU Aβ- group exhibited the lowest percentage of SIEs. After adjustment for global cognitive impairment, aMCI plasma Aβ+ continued to demonstrate greater SIEs on tests tapping the failure to recover from proactive semantic interference (frPSI) as compared to the aMCI Aβ-group. Using pre-established cut-offs for frPSI impairment, 8.3% of CU Aβ- participants evidenced deficits, compared to 37.8% of aMCI Aβ-, and 74.0% of aMCI Aβ+. SIEs reflecting frPSI were associated with aMCI Aβ+ status based on the Aβ42/40 ratio. Results suggest the importance of SIEs as salient cognitive markers that map onto underlying AD pathology in the blood.

Transient susceptibility to interference at event boundaries impacts long-term memory of naturalistic episodes

ABSTRACT During ongoing narratives, event boundaries trigger processes relevant for subsequent memory. Previous work has shown that novel, unrelated input presented at an event boundary can retroactively interfere with short-term retention of the preceding event. This interference was attributed to a perturbation of offset-related processes taking place within seconds after encoding and supporting the binding of elements into a coherent event memory. However, the temporal specificity of this memory interference and whether its impact extends to longer retention delays has not been addressed. Here, participants viewed either individual or pairs of short narrative movie clips. Susceptibility to interference at event boundaries was probed by presenting the second clip either immediately after the first, or with a 2s encoding delay. In free and cued recall, after 20 min and 24 h, only memory for movie clips that were immediately followed by a second clip was reduced compared to clips shown in isolation. Intact offset-related processes (as indexed by successful recall of the first movie) did not negatively affect encoding of the subsequent clip. Together, these results indicate that the 2s time-window immediately after an event is relevant for successful consolidation and long-term retention of memory.

Executive functions involved in thought suppression: An attempt to integrate research in two paradigms

There are two main thought suppression research paradigms: the White Bear and Think/No-Think paradigms. In Think/No-Think research, thought suppression is effective and is considered to be mediated by prepotent response inhibition. Conversely, in White Bear studies, thought suppression is counterproductive and appears to engage resistance to proactive interference. However, findings regarding the involvement of these executive functions in each task are mixed. In the current study, two thought suppression procedures were compared. Using Friedman and Miyake’s inhibitory functions model (2004) it was investigated whether the differences between thought suppression tasks can be explained by involvement of different executive functions. The results showed that the suppression phases of both procedures were correlated, but the outcomes of suppression were unrelated. There was no evidence supporting the involvement of the examined executive functions in either thought suppression task. Commonalities and discrepancies of the two tasks are discussed along with their external validity.

Research of productivity and interlayer interference mechanism of multilayer co-production in reservoirs with multi-pressure systems

Abstract Due to the differences of physical and fluid properties in vertical oil layers, the interlayer contradictions are prominent and affect the reservoir utilization degree seriously. Therefore, the coordination between reasonable bottom-hole flow pressure and optimal production, as well as the reduction of interlayer interference are the primary concerns during the co-production of multi-layer oil reservoirs. Based on the reservoir engineering and fluid mechanics in porous media theory, this work adopt the comprehensive pressure system and consider the interlayer interference to establish a multi-branch horizontal well productivity model and interlayer interference mathematical model. By analyzing the main controlling factors and interference mechanisms, this article establishes a pattern of interlayer interference, and improves the quantitative characterization interlayer interference theory in multi-layer combined mining. The study has shown that: (1) The interlayer interference is beneficial for balancing the production of different layers and improving development efficiency, it is greatly affected by interlayer heterogeneity; (2) When the number of layers exceeds 2 layers, the interference coefficient increases; With the increase of the layer thickness, the thicker oil layers have higher productivity, and the thickness of layer has a significant effect on the production of low-pressure layer; When the production pressure difference increases, the interlayer interference can be reduced; (3) The interlayer interference mathematical model constructed in this paper has high prediction accuracy and strong practicality, which has theoretical guidance significance for the division of strata in comprehensive adjustment of reservoirs.

Rapid instructed task learning is impaired after stroke and associated with impairments in prepotent inhibition and processing speed.

Motor rehabilitation is a central contributor to motor recovery after stroke. Rehabilitation could be hampered by stroke-associated cognitive impairments such as the decreased ability to follow instructions. Rapid instructed task learning (RITL) was never directly studied in older adults and subjects with stroke. The aim of this study was to assess RITL following stroke and its underlying cognitive determinants. Thirty-one subjects with chronic stroke and 36 age-matched controls completed a computerized cognitive examination that included an antisaccade task for measuring prepotent inhibition and processing speed and stimulus-response association task (NEXT) for measuring RITL and proactive inhibition. RITL abilities were impaired after stroke (d = 0.72), together with prepotent inhibition (d = 0.71) and processing speed (d = 1.12). A correlation analysis revealed that RITL is associated with prepotent inhibition abilities and with processing speed. Subjects with stroke show impairments in the ability to follow instructions, that may be related to their impaired prepotent inhibition and processing speed. The causal effect of RITL impairments on the responsivity to rehabilitation and on motor recovery should be examined. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Conceptual masking disrupts change-detection performance.

The present study investigated the effects of long-term knowledge on backward masking interference in visual working memory (VWM) by varying the similarity of mask stimuli along categorical dimensions. To-be-remembered items and masks were taken from categories controlled for perceptual distinctiveness and distinctiveness in kinds (e.g., there are many kinds of cars and few kinds of coffee mugs). Participants completed a change-detection task in which the memory array consisted of exemplars from either a similar or distinctive category, followed by a mask array of items from the same category (conceptually similar versus conceptually distinct categories), a different category, or no mask. The results over two experiments showed greater interference from conceptually similar masks as compared with the other conditions across stimulus onset asynchrony (SOA) conditions, suggesting masking with conceptually similar categories leads to more interference even when masks are shown well after the stimulus. These results have important implications for both the nature and time course of long-term conceptual knowledge influencing VWM, particularly when using complex real-world objects.

Barcode activity in a recurrent network model of the hippocampus enables efficient memory binding.

Forming an episodic memory requires binding together disparate elements that co-occur in a single experience. One model of this process is that neurons representing different components of a memory bind to an "index" - a subset of neurons unique to that memory. Evidence for this model has recently been found in chickadees, which use hippocampal memory to store and recall locations of cached food. Chickadee hippocampus produces sparse, high-dimensional patterns ("barcodes") that uniquely specify each caching event. Unexpectedly, the same neurons that participate in barcodes also exhibit conventional place tuning. It is unknown how barcode activity is generated, and what role it plays in memory formation and retrieval. It is also unclear how a memory index (e.g. barcodes) could function in the same neural population that represents memory content (e.g. place). Here, we design a biologically plausible model that generates barcodes and uses them to bind experiential content. Our model generates barcodes from place inputs through the chaotic dynamics of a recurrent neural network and uses Hebbian plasticity to store barcodes as attractor states. The model matches experimental observations that memory indices (barcodes) and content signals (place tuning) are randomly intermixed in the activity of single neurons. We demonstrate that barcodes reduce memory interference between correlated experiences. We also show that place tuning plays a complementary role to barcodes, enabling flexible, contextually-appropriate memory retrieval. Finally, our model is compatible with previous models of the hippocampus as generating a predictive map. Distinct predictive and indexing functions of the network are achieved via an adjustment of global recurrent gain. Our results suggest how the hippocampus may use barcodes to resolve fundamental tensions between memory specificity (pattern separation) and flexible recall (pattern completion) in general memory systems.

The association between physical activity and memory interference.

Habitual physical activity has been shown to improve memory performance, yet investigations into its effects concerning memory interference remain limited. Additionally, minimal research has evaluated the association between habitual physical activity behaviors occurring in different contexts (e.g., walking, basketball, swimming) and memory. Based on these gaps in the literature, the present set of six experiments evaluated the association between contextually-different physical activity behaviors (e.g., individual physical activities, physical activities performed in social settings) and memory interference among young adult samples from America and Germany. Across six experiments, we reliably demonstrated that Germans exhibited greater memory performance than Americans. We also reliably demonstrated that contextually-different physical activities are not associated with memory performance or attenuated memory interference.

Experimental research on the horizontally getting together behaviors of acoustically manipulated bi-particle

This study aims at the controllability of acoustically manipulated non-contact aggregation of bi-particle. Based on the acoustic wave radiation model of the transducer and the acoustic wave interference theory, the mathematical model between the spatial levitation point and the phase of the phased array ultrasonic array unit is established. A double-sided phased array test system was developed and the phase calculation algorithm for independently manipulating bi-particle was optimized. The algorithm is capable of independently distributing the energy applied to each levitation point. Through simulation and experiment, the horizontally aggregation characteristics of two levitated particles are investigated, and a interesting relationship between particles aggregation and standing wave phase difference is revealed, which follows the law of “attraction in the same phase but repulsion in the opposite phase”. By adjusting the tilt angle of the standing wave acoustic trap, the critical distance when particles to accelerate and collision is sharply reduced from 1.5λ to 0.5λ, which provides a new perspective and potential application path for acoustic manipulation technology.

Polarization insensitive and wideband terahertz absorber using high-impedance resistive material of RuO2

This paper introduces a novel, cost-effective solution designed to achieve large absorption bandwidth within the THz spectrum employing a miniaturized, single-layer metamaterial structure. The designed structure features a single circular ring composed of an ohmic resistive sheet with notably higher sheet resistance than traditional metallic resonators. This distinctive design is implemented on a lossy dielectric polyimide substrate with a backing of metallic gold. Our developed absorbing structure demonstrates the capability to achieve a substantial absorption bandwidth ranging from 3.78 to 4.25 THz, maintaining a consistent absorption rate of over 90%. Moreover, we conducted an analysis to assess its absorption performance under various sheet resistance values within the top layer. Additionally, we characterized its angular stability and polarization insensitivity through oblique incident and polarization angle analysis. Finally, an RLC circuital and interference theory approach is adopted to justify its simulated results. The proposed absorber shows potential for a broad spectrum of applications, encompassing communication, imaging, and diverse integrated circuits operating within the THz band.

Infrared and Harsh Light Visible Image Fusion Using an Environmental Light Perception Network.

The complementary combination of emphasizing target objects in infrared images and rich texture details in visible images can effectively enhance the information entropy of fused images, thereby providing substantial assistance for downstream composite high-level vision tasks, such as nighttime vehicle intelligent driving. However, mainstream fusion algorithms lack specific research on the contradiction between the low information entropy and high pixel intensity of visible images under harsh light nighttime road environments. As a result, fusion algorithms that perform well in normal conditions can only produce low information entropy fusion images similar to the information distribution of visible images under harsh light interference. In response to these problems, we designed an image fusion network resilient to harsh light environment interference, incorporating entropy and information theory principles to enhance robustness and information retention. Specifically, an edge feature extraction module was designed to extract key edge features of salient targets to optimize fusion information entropy. Additionally, a harsh light environment aware (HLEA) module was proposed to avoid the decrease in fusion image quality caused by the contradiction between low information entropy and high pixel intensity based on the information distribution characteristics of harsh light visible images. Finally, an edge-guided hierarchical fusion (EGHF) module was designed to achieve robust feature fusion, minimizing irrelevant noise entropy and maximizing useful information entropy. Extensive experiments demonstrate that, compared to other advanced algorithms, the method proposed fusion results contain more useful information and have significant advantages in high-level vision tasks under harsh nighttime lighting conditions.

Conserving a sense of self despite significantly impaired short-term memory through songwriting and formative events

This case study reflects on the use of improvisation and songwriting to support a patient with significantly impaired short-term memory and long-term memory interference as a result of acquired brain injury. Memory has long been associated with personal identity, linking the past with the present, and enabling us to project into the future. This continuity of consciousness helps us to learn from, and make sense of our experiences, strengthening our internal representation of self. Disruption to short-term memory can significantly impact decision making, planning and initiation, all of which are key components of personal identity and self-expression. Supporting patient autonomy and self-expression through improvisation, and crafting lyrical content around personal preferences and events, sessions were designed to bolster his internalised sense of self through both revisiting old memories and facilitating new memory formation within the present. While short-term memory has been considered a conduit to long-term memory consolidation, and integral to the individual’s self-expression, this case study implies short-term memory was neither the gatekeeper to formation of long-term memories, nor critical to maintaining a sense of self, and reflects on how music helped the client create and access new learning beyond procedural memories, anchoring the self in newly internalised self-expression.