Configural Learning Research Articles

Revisiting contextual cueing effects: The role of perceptual processing.

Incidental learning of invariant configurations of items can facilitate visual search, which is termed contextual cueing effect. Previous debates about the mechanisms of the contextual cueing effect mainly focused on the roles of attentional guidance and response-related components. Because the time for perceiving displays is very short, few studies have revealed the role of initial perceptual processing. Thus, in the present study, we manipulated the key variable of display contrast to prolong the perceptual processing duration in low-contrast displays. With response-time and eye-movement recording, the study explored the role of initial perceptual processing. In addition, we examined the roles of attentional guidance and response-related components. From three experiments we found: In addition to the role of attentional guidance, the initial perceptual processing could also contribute to a contextual cueing effect in a low-contrast condition; there was only the facilitation from attentional guidance in a high-contrast condition. These results suggest that perceptual processing can also play a role if the perceptual processing time is prolonged, but the main role involves improved attentional guidance.

Precommissural and postcommissural fornix microstructure in healthy aging and cognition.

The fornix is a key tract of the hippocampal formation, whose status is presumed to contribute to age-related cognitive decline. The precommissural and postcommissural fornix subdivisions form respective basal forebrain/frontal and diencephalic networks that may differentially affect aging and cognition. We employed multi-parametric magnetic resonance imaging (MRI) including neurite orientation density and dispersion imaging, quantitative magnetization transfer (qMT), and T1-relaxometry MRI to investigate the microstructural properties of these fornix subdivisions and their relationship with aging and cognition in 149 asymptomatic participants (38–71 years). Aging was associated with increased free water signal and reductions in myelin-sensitive R1 and qMT indices but no apparent axon density differences in both precommissural and postcommissural fibers. Precommissural relative to postcommissural fibers showed a distinct microstructural pattern characterised by larger free water signal and axon orientation dispersion, with lower apparent myelin and axon density. Furthermore, differences in postcommissural microstructure were related to performance differences in object-location paired-associate learning. These results provide novel in vivo neuroimaging evidence for distinct microstructural properties of precommissural and postcommissural fibers that are consistent with their anatomy as found in axonal tracer studies, as well as for a contribution of postcommissural fibers to the learning of spatial configurations.

Recognition of incidentally learned visual search arrays is supported by fixational eye movements.

Repeated encounter of abstract target-distractor letter arrangements leads to improved visual search for such displays. This contextual-cueing effect is attributed to incidental learning of display configurations. Whether observers can consciously access the memory underlying the cueing effect is still a controversial issue. The current study uses a novel recognition task and eyetracking to tackle this question. Experiment 1 investigated observers' ability to recognize or "generate" the display quadrant of the target in a previous search array when the target was now substituted by distractor element as well as where observers' eye fixations would fall while they freely viewed the recognition display, examining the link between the fixation pattern and explicit recognition judgments. Experiment 2 tested whether eye fixations would serve a critical role for explicit retrieval from context memory. Experiment 3 asked whether eye fixations of the target region are critical for context-based facilitation of search reaction times to manifest. The results revealed longer fixational dwell times in the target quadrant for learned relative to foil displays. Further, explicit recognition was enhanced, and above chance level, when observers were made to fixate the target quadrant as compared to when they were prevented from doing so. However, the manifestation of contextual cueing of visual search did itself not require fixations of the target quadrant. Moreover, contextual-cueing of search reaction times was significantly correlated with both fixational dwell times and observers' explicit generation performance. The results argue in favor of contextual cueing of visual search being the result of a single, explicit, memory system, though it could nevertheless receive support from separable-automatic versus controlled-retrieval processes. Fixational eye movements, that is, the directed overt allocation of visual attention, provide an interface between these processes in context cueing. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

SediNet: a configurable deep learning model for mixed qualitative and quantitative optical granulometry

AbstractI describe a configurable machine‐learning framework to estimate a suite of continuous and categorical sedimentological properties from photographic imagery of sediment, and to exemplify how machine learning can be a powerful and flexible tool for automated quantitative and qualitative measurements from remotely sensed imagery. The model is tested on a dataset consisting of 409 images and associated detailed label data. The data are from a much wider sedimentological spectrum than previous optical granulometry studies, consisting of both well‐ and poorly sorted sediment, terrigenous, carbonate, and volcaniclastic sands and gravels and their mixtures, and grain sizes spanning over two orders of magnitude. I demonstrate the model framework by configuring it in several ways, to estimate two categories (describing grain shape and population, respectively) and nine numeric grain size percentiles in pixels from a single input image. Grain size is then recovered using the physical size of a pixel. Finally, I demonstrate that the model can be configured and trained to estimate equivalent sieve diameters directly from image features, without the need for area‐to‐mass conversion formulas and without even knowing the scale of one pixel. Thus it is the only optical granulometry method proposed to date that does not necessarily require image scaling. The flexibility of the model framework should facilitate numerous application in the spatiotemporal monitoring of the grain size distribution, shape, mineralogy and other quantities of interest of sedimentary deposits as they evolve, as well as other texture‐based proxies extracted from remotely sensed imagery. © 2019 John Wiley & Sons, Ltd.

The advantage of globally visible landmarks for spatial learning

Despite much recent interest, it is unclear which types of landmarks are best suited for survey knowledge acquisition. Thus, we investigated the accuracy of survey knowledge after the learning of sequentially visible (local) landmarks and simultaneously visible (global) landmarks from a first-person perspective during navigation through a virtual city. We also assessed systematically the role of working memory during navigation with a concurrent spatial-sequential task. Our results indicate that the learning of local and global landmark configurations are similarly affected by this concurrent task. We also find greater accuracy for the acquisition of global landmark knowledge compared to local landmark knowledge, especially for participants with high working memory capacity.

Medial prefrontal and ventral hippocampal contributions to incidental context learning and memory in adolescent rats.

The Context Preexposure Facilitation Effect (CPFE) is a contextual fear conditioning (CFC) paradigm in which context learning, context-shock learning, and retrieval of contextual fear occur in three distinct phases. The medial prefrontal cortex (mPFC), dorsal hippocampus (dHPC), and ventral hippocampus (vHPC) are required for the acquisition and/or consolidation of a context representation during incidental context exposure (Heroux et al., 2017; Robinson-Drummer et al., 2016; Rudy & Matus-Amat, 2006). This exposure also induces the expression of the immediate early genes (IEGs) c-Fos, Arc, Egr-1, and Npas4 in these regions (Heroux et al., 2018, 2019). Despite these studies, it is still unclear how mPFC and vHPC contribute to incidental context learning and memory. The current study examined whether prefrontal or ventral hippocampal inactivation during context preexposure interferes with long-term context memory and IEG activity in the mPFC, vHPC, dHPC and the ventral midline thalamus (VMT, a region connected to both the mPFC and HPC). Adolescent Long-Evans rats were given intra-mPFC (Experiment 1) or intra-vHPC (Experiment 2) infusions of the GABAA receptor agonist muscimol or PBS prior to context preexposure, and then were sacrificed 30 min later and whole mPFC, dHPC, vHPC, and VMT were collected and assayed for IEG mRNA expression via qPCR. Prefrontal or ventral hippocampal inactivation during context exposure abolished subsequent post-shock and retention test freezing in behaviorally-tested littermates of the sacrificed groups. In Experiment 1, prefrontal inactivation reduced expression of c-Fos, Arc, Egr-1, and Npas4 in the mPFC, c-Fos, Arc, and Npas4 in the vHPC, and c-Fos in the VMT, to the level of behaviorally-naïve home-cage controls. Prefrontal inactivation did not alter IEG expression in the dHPC during context exposure. In Experiment 2, ventral hippocampal inactivation impaired expression of all IEGs in the mPFC, dHPC, and vHPC, with no effect in the VMT. Taken together, these results suggest that context memory processes on the preexposure day of the CPFE may depend on mPFC-vHPC circuitry not typically emphasized in studies of incidental or configural learning and memory.

Contextual cueing in older adults: Slow initial learning but flexible use of distractor configurations

ABSTRACTLearned spatial regularities can efficiently guide visual search. This effect has been extensively studied using the contextual cueing paradigm. We investigated age-related changes in the initial learning of contextual configurations and the relearning after target relocation. Younger and older participants completed a contextual cueing experiment on two days. On day one, they were tested with a standard contextual cueing task. On day two, for the repeated displays the location of the targets was moved while keeping the distractor configurations unchanged. Older participants developed a reliable contextual cueing effect but the emergence of this effect required more repetitions compared to younger individuals. Contextual cueing was apparent quickly after target relocation in younger and older participants. Especially in older adults, the fast updating might be due to learned distractor-distractor associations rather than the updating of target-distractor configurations.

Characterizing the neural circuitry associated with configural threat learning

Contextual threat learning is often associated with two processes: elemental and configural learning. Few studies have examined configural learning where subjects form a representation of the threat-related context as a gestalt whole from the individual features in the environment. The goal of the current study was to compare and contrast neural circuitry recruited by variation in demands placed on configural threat encoding. Subjects (N = 25) completed a configural threat learning task, where we manipulated the amount of configural encoding required to learn the threat association (low demand: changes to a discrete element of the context; and high demand: rearrangement of elements). US expectancy ratings, skin conductance responses (SCR), and functional magnetic resonance imaging (fMRI) were collected. Subjects successfully learned the configural threat association as measured by US expectancy ratings, SCR, and BOLD activity. Hippocampal and amygdala region of interest analyses indicated differential configural threat learning and predicted SCR measures of learning. Furthermore, whole brain analyses identified four circuits that were impacted by the amount of differential configural encoding required, but none correlated with SCR. These results set the stage for a more detailed understanding of how configural threat learning is instantiated in the brain—an important mechanism associated with PTSD and other fear-related disorders.

Acute stress – but not aversive scene content – impairs spatial configuration learning

ABSTRACTContextual learning pervades our perception and cognition and plays a critical role in adjusting to aversive and stressful events. Our ability to memorise spatial context has been studied extensively with the contextual cueing paradigm, in which participants search for targets among simple distractor cues and show search advantages for distractor configurations that repeat across trials. Mixed evidence suggests that confrontation with adversity can enhance as well as impair the contextual cueing effect. We aimed to investigate this relationship more systematically by devising a contextual cueing task that tests spatial configuration learning within complex visual scenes that were emotionally neutral or negative (Study 1) and was preceded by the Maastricht Acute Stress Test (MAST) or a no-stress control condition (Study 2). We demonstrate a robust contextual cueing effect that was comparable across negative and neutral scenes (Study 1). In Study 2, acute stress disrupted spatial configuration learning irrespective of scene valence and endogenous cortisol reactivity to stress. Together with the emerging evidence in the literature, our findings suggest that spatial configuration learning may be subject to complex regulation as a function of spatial or temporal proximity to a stressor, with potential implications for the development of stress-related psychopathology.

Symbolic Modeling of Asynchronous Neural Dynamics Reveals Potential Synchronous Roots for the Emergence of Awareness.

A new computational framework implementing asynchronous neural dynamics is used to address the duality between synchronous vs. asynchronous processes, and their possible relation to conscious vs. unconscious behaviors. Extending previous results on modeling the first three levels of animal awareness, this formalism is used here to produce the execution traces of parallel threads that implement these models. Running simulations demonstrate how sensory stimuli associated with a population of excitatory neurons inhibit in turn other neural assemblies i.e., a kind of neuronal asynchronous wiring/unwiring process that is reflected in the progressive trimming of execution traces. Whereas, reactive behaviors relying on configural learning produce vanishing traces, the learning of a rule and its later application produce persistent traces revealing potential synchronous roots of animal awareness. In contrast, to previous formalisms that use analytical and/or statistical methods to search for patterns existing in a brain, this new framework proposes a tool for studying the emergence of brain structures that might be associated with higher level cognitive capabilities.

PSO active learning of XGBoost and spatiotemporal data for PM2.5 sensor calibration

Ambient PM2.5 concentrations affect human health and natural environment. Government-built PM2.5 monitoring supersites are accurate but cannot provide a dense coverage of the air quality index (AQI) monitoring. Broadly-distributed PM2.5 microsite sensors can complement supersites for fine-grained monitoring. However, due to the low cost of microsite sensors, the accuracy of the raw AQI measurements is not high enough for monitoring purpose. Calibration of low-cost sensors is thus a necessary processing step to enhance measurement fidelity. This paper presents a particle swarm optimization (PSO) based active learning of optimal configurations of XGBoost and spatiotemporal data for PM2.5 microsite sensor calibration. The experimental results show that PSO active learning of the optimal configurations of XGBoost and spatiotemporal data can calibrate low-cost PM2.5 microsite sensors to achieve high accuracy by reference to governmental supersites.

Configural learning in freshly collected, smart, wild Lymnaea.

An inbred laboratory strain (W-strain) of Lymnaeastagnalis is capable of configural learning. Configural learning, a higher form of learning, is an association between two stimuli experienced together that is different from the simple sum of their components. In our configural learning procedure, a food odour (carrot odour, CO) is experienced together with crayfish effluent (CE) (i.e. CO+CE). Following configural learning, CO now elicits a fear state rather than increased feeding. We hypothesized that freshly collected wild strains of predator-experienced L. stagnalis also possess the ability to form configural learning, even though they experience crayfish daily in their environment. We therefore subjected freshly collected wild strain L. stagnalis to the configural learning procedure. Following the configural learning procedure, CO became a risk signal and evoked anti-predator behaviours. Thus, configural learning was demonstrated in wild, freshly collected snails. We believe that configural learning occurs in the snail's natural environment and is important for their survival.

Configural learning: a higher form of learning in Lymnaea.

Events typically occur in a specific context and the ability to assign importance to this occurrence plays a significant role in memory formation and recall. When the scent of a crayfish predator (CE) is encountered in Lymnaea stagnalis strains known to be predator experienced (e.g. the W-strain), enhancement of memory formation and depression of feeding occur, which are part of a suite of anti-predator behaviours. We hypothesized that Lymnaea possess a form of higher-order conditioning, namely configural learning. We tested this by simultaneously exposing W-strain Lymnaea to a carrot food odour (CO) and predator scent (CE). Two hours later, we operantly conditioned these snails with a single 0.5 h training session in CO to determine whether training in CO results in long-term memory (LTM) formation. A series of control experiments followed and demonstrated that only the CO+CE snails trained in CO had acquired enhanced memory-forming ability. Additionally, following CE+CO pairing, CO no longer elicited an increased feeding response. Hence, snails have the ability to undergo configural learning. Following configural learning, CO becomes a risk signal and evokes behavioural responses phenotypically similar to those elicited by exposure to CE.

Managing alliance configuration and dyadic learning performance in coopetition

Firms decide to form global alliances to seek new knowledge and innovation from different sources, even from their competitors. However, the mechanism for managing both cooperation and competition in these knowledge-seeking alliances are much less understood. This research is intended to disentangle the learning race phenomenon in an alliance of two competing companies. We raise questions on how firms could reconcile the dilemma between cooperation and competition and what is the best configuration for an alliance portfolio that contributes to a dyadic learning performance in coopetition. We tested the hypothesis with 680 samples from 136 firms in the biotech industry from 1998-2002. The results supported all the hypotheses as follows: strong ties have an inverted U-shaped effect on specific learning capability gap (SLCG) and the technological diversity has a role in reversing the relationship between the strong ties and SLCG which previously was seen as an inverted U-shape, but became U-shaped.

Learning Complex Spatio-Temporal Configurations of Body Joints for Online Activity Recognition

Geometric dynamic configurations of body joints play an essential role in distinguishing different human activities. However, many existing human activity recognition approaches lack the capability of automatically learning these configurations from sequences of joints in four-dimensional space (spatio and temporal). In this paper, the authors propose an automatic joint configuration learning method, based on dictionary learning and sparse representation. The proposed method achieves the following features: 1) it automatically learns dynamic spatio-temporal geometric configurations of body joints, involved in activities, in a simple way; 2) it dispenses with the hand crafted feature designing process and provides a new method to organize joint coordinate data as fixed length column vectors, which are suitable for dictionary learning; 3) it replaces the conventional bag of words model with sparse coding method; words in learned dictionary capture subactivity features, and the frequencies of different words appearing in different activities characterize the categories of global activity; 4) it is robust to time misalignment and can classify any length of video sequence (online classification) in real time; 5) it is easy to combine this method with other forms of data for better performance, because of its data driven nature and flexible framework. The proposed method is tested with three state-of-the-art public human activity recognition datasets and the results are found to be better than those of CAD-60 dataset, and comparable to those of both MSR Action 3D and MSR Daily Activity datasets (source codes are publicly available at https://github.com/jinqijinqi/SparseCodingDictionaryLearningHumanActivityRecognition ).

Gradual acquisition of visuospatial associative memory representations via the dorsal precuneus.

Activation of parietal cortex structures like the precuneus is commonly observed during explicit memory retrieval, but the role of parietal cortices in encoding has only recently been appreciated and is still poorly understood. Considering the importance of the precuneus in human visual attention and imagery, we aimed to assess a potential role for the precuneus in the encoding of visuospatial representations into long-term memory. We therefore investigated the acquisition of constant versus repeatedly shuffled configurations of icons on background images over five subsequent days in 32 young, healthy volunteers. Functional magnetic resonance imaging was conducted on Days 1, 2, and 5, and persistent memory traces were assessed by a delayed memory test after another 5 days. Constant compared to shuffled configurations were associated with significant improvement of position recognition from Day 1 to 5 and better delayed memory performance. Bilateral dorsal precuneus activations separated constant from shuffled configurations from Day 2 onward, and coactivation of the precuneus and hippocampus dissociated recognized and forgotten configurations, irrespective of condition. Furthermore, learning of constant configurations elicited increased functional coupling of the precuneus with dorsal and ventral visual stream structures. Our results identify the precuneus as a key brain structure in the acquisition of detailed visuospatial information by orchestrating a parieto-occipito-temporal network.

When is the rat retrosplenial cortex required for stimulus integration?

The rodent retrosplenial cortex is known to be vital for spatial cognition, but evidence has also pointed to a role in processing nonspatial information. It has been suggested that the retrosplenial cortex may serve as a site of integration of incoming sensory information. To examine this proposal, the current set of experiments assessed the impact of excitotoxic lesions in the retrosplenial cortex on two behavioral tasks that tax animals’ ability to process multiple and overlapping environmental stimuli. In Experiment 1, rats with retrosplenial lesions acquired a negative patterning discrimination, a form of configural learning that can be solved only by learning the conjunction of cues. Subsequent transfer tests confirmed that both the lesion and control animals had solved the task by using configural representations. Furthermore, in Experiment 2, a 2nd cohort of retrosplenial lesion animals successfully acquired conditioned inhibition. Nevertheless, the same animals failed a subsequent summation test that assesses the ability to transfer what has been learned about one stimulus to another stimulus in the absence of reinforcement. Taken together, these results suggest that in the nonspatial domain, the retrosplenial cortex is not required for forming associations between multiple or overlapping environmental stimuli and, consequently, retrosplenial engagement in such processes is more selective than was previously envisaged.

The discriminative stimulus effects of nicotine & ethanol with two distinct olfactory contexts in male and female rats

Odor cues and interoceptive cues can combine in promoting drug seeking behavior. Drug discrimination methodology was combined with odor-context conditioning in 8 male and 8 female rats. One drug (nicotine or EtOH) plus odorant (peppermint or anise) compound functioned as setting the occasion for sessions of food-reinforced nose poke responses (i.e., the SD) that were maintained on a variable interval 30 s schedule (VI-30), whereas the opposite drug (EtOH or nicotine) plus odorant (anise or peppermint) compound predicted intermixed sessions of non-reinforcement of nose poking (i.e., the SΔ). During brief non-reinforcement tests conducted with each condition there was significantly greater responding under the SD drug plus odor compound compared to the SΔ drug plus odor compound. Discriminative control was evident and there was a sex by stimulus role interaction with greater SΔ responding in females. The odor contexts and drug contexts alone also sustained strong stimulus control but to a lesser extent compared to the full drug-odor compounds. These data suggest configural learning among drug and odor cues.

Variability influences generalization in implicit learning of spatial configurations

Variability influences generalization in implicit learning of spatial configurations

Bimodal Patterning Discrimination in Harnessed Honey Bees

In natural environments, stimuli and events learned by animals usually occur in a combination of more than one sensory modality. An important problem in experimental psychology has been thus to understand how organisms learn about multimodal compounds and how they discriminate this compounds from their unimodal constituents. Here we tested the ability of honey bees to learn bimodal patterning discriminations in which a visual-olfactory compound (AB) should be differentiated from its visual (A) and olfactory (B) elements. We found that harnessed bees trained in classical conditioning of the proboscis extension reflex (PER) are able to solve bimodal positive and negative patterning (NP) tasks. In positive patterning (PP), bees learned to respond significantly more to a bimodal reinforced compound (AB+) than to non-reinforced presentations of single visual (A-) or olfactory (B-) elements. In NP, bees learned to suppress their responses to a non-reinforced compound (AB-) and increase their responses to reinforced presentations of visual (A+) or olfactory (B+) elements alone. We compared the effect of two different inter-trial intervals (ITI) in our conditioning approaches. Whereas an ITI of 8 min allowed solving both PP and NP, only PP could be solved with a shorter ITI of 3 min. In all successful cases of bimodal PP and NP, bees were still able to discriminate between reinforced and non-reinforced stimuli in memory tests performed one hour after conditioning. The analysis of individual performances in PP and NP revealed that different learning strategies emerged in distinct individuals. Both in PP and NP, high levels of generalization were found between elements and compound at the individual level, suggesting a similar difficulty for bees to solve these bimodal patterning tasks. We discuss our results in light of elemental and configural learning theories that may support the strategies adopted by honey bees to solve bimodal PP or NP discriminations.