The Connection Between Associative Memory and Semantic Similarity: Evidence From Fan Experiments and Distributional Models.

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To assess cognitive-structural associations between attitudes and values, we measured the speed with which participants judged the truth of sentences asserting that particular attitude (e.g., affirmative action) and value (e.g., equality) concepts were related. Results were well-described by Anderson's (1983) ACT* model. First, sentences containing attitude-value pairs either high or low in semantic relatedness were responded to more quickly than those containing pairs moderate in relatedness. Second, we predicted and found stronger priming effects when either the prime or the target was strong (i.e., personally important) than when it was weak. Finally, our data revealed a classic “fan effect;” attitude and value primes produced more response facilitation when they had few, rather than many, cognitive associates. Moreover, values had more associates than did attitudes, and this difference accounted for the greater effectiveness of attitudes than values as primes. Our results document structural differenc...

Does hyperpriming reveal impaired spreading of activation in schizophrenia?

Semantic distance is a determining factor in cognitive processes, such as semantic priming, operating upon semantic memory. The main computational approach to compute semantic distance is through latent semantic analysis (LSA). However, objections have been raised against this approach, mainly in its failure at predicting semantic priming. We propose a novel approach to computing semantic distance, based on network science methodology. Path length in a semantic network represents the amount of steps needed to traverse from 1 word in the network to the other. We examine whether path length can be used as a measure of semantic distance, by investigating how path length affect performance in a semantic relatedness judgment task and recall from memory. Our results show a differential effect on performance: Up to 4 steps separating between word-pairs, participants exhibit an increase in reaction time (RT) and decrease in the percentage of word-pairs judged as related. From 4 steps onward, participants exhibit a significant decrease in RT and the word-pairs are dominantly judged as unrelated. Furthermore, we show that as path length between word-pairs increases, success in free- and cued-recall decreases. Finally, we demonstrate how our measure outperforms computational methods measuring semantic distance (LSA and positive pointwise mutual information) in predicting participants RT and subjective judgments of semantic strength. Thus, we provide a computational alternative to computing semantic distance. Furthermore, this approach addresses key issues in cognitive theory, namely the breadth of the spreading activation process and the effect of semantic distance on memory retrieval. (PsycINFO Database Record

Large-scale word association datasets are both important tools used in psycholinguistics and used as models that capture meaning when considered as semantic networks. Here, we present word association norms for Rioplatense Spanish, a variant spoken in Argentina and Uruguay. The norms were derived through a large-scale crowd-sourced continued word association task in which participants give three associations to a list of cue words. Covering over 13,000 words and +3.6 M responses, it is currently the most extensive dataset available for Spanish. We compare the obtained dataset with previous studies in Dutch and English to investigate the role of grammatical gender and studies that used Iberian Spanish to test generalizability to other Spanish variants. Finally, we evaluated the validity of our data in word processing (lexical decision reaction times) and semantic (similarity judgment) tasks. Our results demonstrate that network measures such as in-degree provide a good prediction of lexical decision response times. Analyzing semantic similarity judgments showed that results replicate and extend previous findings demonstrating that semantic similarity derived using spreading activation or spectral methods outperform word embeddings trained on text corpora.

The age-related associative memory deficit can be alleviated, under some conditions, when to-be-remembered associations are semantically related. In this study, we explored the experimental conditions in which older adults benefited from semantic relatedness and those that hindered any associative memory improvement. We did so by manipulating the level of semantic support within the associations presented at encoding and within the recombined pairs (i.e., the lures) at retrieval, such that pairs with high semantic support at encoding were recombined into pairs with equally high or with lower level of semantic support, and vice versa. We predicted that semantic relatedness would benefit older adults' associative memory when there was a decrease in semantic support from encoding to retrieval. Conversely, older adults' associative memory would be hindered when a recombination was equally or more familiar than the studied association. In Experiment 1, we manipulated the presence versus absence of semantic relatedness within associations both at encoding and at retrieval. In Experiment 2, we manipulated the frequency of related associations at encoding and at retrieval. Taken together, the results showed that older adults' associative memory was better in conditions in which associations closely matched semantic knowledge at encoding and were recombined into associations with no or less semantic support at retrieval. In contrast, older adults' performance was worse for semantically poorer associations at encoding that were recombined into associations with greater semantic support at retrieval. This suggests that older adults' associative memory can be improved by semantic support under specific experimental conditions only. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

It is known that in the process of memory formation for new experiences, neurons in many regions of the brain are activated. In particular, neurons of the CA1 area of the hippocampus are activated during memory formation when animal first observe a new context [1]. However, it is not quite clear how the activity of CA1 neurons changes during memory formation and retrieval. Moreover, the question remains what changes in neuronal activity are observed in old animals during memory formation and retrieval. In our work, we investigated changes in the calcium activity of hippocampal CA1 neurons during the formation and retrieval of associative memory of the context model of context preexposure facilitation effect in young and aged mice. Calcium activity of individual neurons was recorded using a miniature microscope (miniscope), which allows optical detection of active neurons through the fluorescence of the calcium sensor. For this purpose, the mice underwent stereotactic surgery in which the calcium fluorescent sensor NCaMP7 was injected into the CA1 area of the hippocampus [2]. Then, a 0.5-mm-diameter GRIN lens was implanted into the studied area, and miniscope mounts were placed on the mouse head. The experiment was performed one week after the surgery. On the first day, the procedure of pretraining was performed: the mice were placed in a new context for 5 minutes free exploration, as a result of which the mice formed a spatial perception of the context. Three days later, the mice were briefly placed in the same context and immediately received footshock for 2s (1.5mA). Thus, the previously formed perception of the context was associated with the animal's state of fear. We tested associative memory three days after shock application: mice were placed in the same context for 5 minutes. A measure of formed associative memory was their level of freezing behaviour in the context. Young mice showed a low level of freezing on the first visit of the context. We also observed a low level of freezing in older mice on the first day of the experiment. At the same time, the retrieval of a previously formed memory significantly increased the level of the freezing in older mice, compared with the first day, indicating that this animal had formed an associative memory of the context. To analyze changes in calcium activity during memory formation and retrieval, we assessed changes in the level of neuronal activity in each individual animal freezing act. Calcium activity of individual CA1 area neurons was recorded during the first visit to the environment and during memory retrieval. In each mouse, about 20 neurons were recorded in the two groups under study in two sessions of the experiment. However, we did not find any significant changes in the number of active neurons in young and old animals at the moments of their fading into the environment. The results indicate that the processes of associative memory formation and retrieval do not manifest themselves in changes in the number of active cells at the moment of the animal freezing behaviour. Possibly, the studied processes of memory formation and retrieval are reflected in other forms of brain activity, such as cognitive maps of the context, which represent a network of cognitively specialized neurons (place fields).

A number of memory models have been proposed. These all have the basic structure that excitatory neurons are reciprocally connected by recurrent connections together with the connections with inhibitory neurons, which yields associative memory (i.e., pattern completion) and successive retrieval of memory. In most of the models, a simple mathematical model for a neuron in the form of a discrete map is adopted. It has not, however, been clarified whether behaviors like associative memory and successive retrieval of memory appear when a biologically plausible neuron model is used. In this paper, we propose a network model for associative memory and successive retrieval of memory based on Pinsky-Rinzel neurons. The state of pattern completion in associative memory can be observed with an appropriate balance of excitatory and inhibitory connection strengths. Increasing of the connection strength of inhibitory interneurons changes the state of memory retrieval from associative memory to successive retrieval of memory. We investigate this transition.

Semantic relatedness means the degree of the nearness of two documents or two terms based on the sameness of their meaning or semantic contents. A method for computing semantic relatedness is crucial in the web mining applications such as search engine, recommendation systems and information retrieval systems, and also in the area of natural language processing. This paper proposes a new technique for measuring semantic relatedness between two terms. It uses Wikipedia as a source of structured world knowledge about the terms of interest while ontologies are used to retrieve the semantically related information in most systems. The proposed method used spreading activation approach over the taxonomy of Wikipedia categories to get the measures of semantic relatedness. Spreading activation strategy is a popular approach in associative retrieval. The proposed method is experienced with the benchmark dataset to show the comparison our approach with some existing approaches.

Effects of Semantic and Associative Relatedness on Automatic Priming

BackgroundFor word production, we may consciously pursue semantic or phonological search strategies, but it is uncertain whether we can retrieve the different aspects of lexical information independently from each other. We therefore studied the spread of semantic information into words produced under exclusively phonemic task demands.Methods42 subjects participated in a letter verbal fluency task, demanding the production of as many s-words as possible in two minutes. Based on curve fittings for the time courses of word production, output spurts (temporal clusters) considered to reflect rapid lexical retrieval based on automatic activation spread, were identified. Semantic and phonemic word relatedness within versus between these clusters was assessed by respective scores (0 meaning no relation, 4 maximum relation).ResultsSubjects produced 27.5 (±9.4) words belonging to 6.7 (±2.4) clusters. Both phonemically and semantically words were more related within clusters than between clusters (phon: 0.33±0.22 vs. 0.19±0.17, p<.01; sem: 0.65±0.29 vs. 0.37±0.29, p<.01). Whereas the extent of phonemic relatedness correlated with high task performance, the contrary was the case for the extent of semantic relatedness.ConclusionThe results indicate that semantic information spread occurs, even if the consciously pursued word search strategy is purely phonological. This, together with the negative correlation between semantic relatedness and verbal output suits the idea of a semantic default mode of lexical search, acting against rapid task performance in the given scenario of phonemic verbal fluency. The simultaneity of enhanced semantic and phonemic word relatedness within the same temporal cluster boundaries suggests an interaction between content and sound-related information whenever a new semantic field has been opened.

The identification of genes related to encoding, storage, and retrieval of memories is a major interest in neuroscience. In the current study, we analyzed the temporal gene expression changes in a neuronal mRNA pool during an olfactory long-term associative memory (LTAM) in Caenorhabditis elegans hermaphrodites. Here, we identified a core set of 712 (538 upregulated and 174 downregulated) genes that follows three distinct temporal peaks demonstrating multiple gene regulation waves in LTAM. Compared with the previously published positive LTAM gene set (Lakhina et al., 2015), 50% of the identified upregulated genes here overlap with the previous dataset, possibly representing stimulus-independent memory-related genes. On the other hand, the remaining genes were not previously identified in positive associative memory and may specifically regulate aversive LTAM. Our results suggest a multistep gene activation process during the formation and retrieval of long-term memory and define general memory-implicated genes as well as conditioning-type-dependent gene sets.SIGNIFICANCE STATEMENT The identification of genes regulating different steps of memory is of major interest in neuroscience. Identification of common memory genes across different learning paradigms and the temporal activation of the genes are poorly studied. Here, we investigated the temporal aspects of Caenorhabditis elegans gene expression changes using aversive olfactory associative long-term memory (LTAM) and identified three major gene activation waves. Like in previous studies, aversive LTAM is also CREB dependent, and CREB activity is necessary immediately after training. Finally, we define a list of memory paradigm-independent core gene sets as well as conditioning-dependent genes.

Creative cognition involves linking weakly or unrelated concepts, enabled by semantic control (inhibiting dominant associations to retrieve weaker ones) or through spreading activation within the semantic system. Semantic aphasia (SA) patients have impaired semantic control despite relatively preserved semantic representations. To date, no studies have examined creativity in SA. It remains unclear how impaired control affects patients' creative potential, and whether spreading activation alone supports this. Creative potential was assessed across three experiments. Experiments 1 and 2 involved 11 SA patients and 25 controls; Experiment 3 included 13 SA patients and 14 controls. In Experiment 1 (category judgement), participants selected five targets from distractors across 24 categories with differing coherence levels (shared features among members). Experiment 2 (constrained category fluency) involved generating five exemplars per category. Creative potential was measured via uniqueness, flexibility, semantic distance and creativity ratings. Experiment 3 (unconstrained fluency) asked participants to name as many Animals as possible in 1 minute, with additional measures of clustering and switching. Although SA cases were unable to shape retrieval to pre-defined associations (in the category judgement task), they showed creative potential in the constrained fluency task. In the unconstrained fluency task, patients were less able to use strategies. However, with fluency controlled, no group differences in creative potential existed. These findings provide the first neuropsychological evidence that spreading activation, even with impaired semantic control, can support creative responses. Creative potential in SA depends on task demands, aligning with broader findings of patients' sensitivity to context.

Few studies have compared interference-based forgetting between item versus associative memory. The memory-system dependent forgetting hypothesis (Hardt, Nader, & Nadel, 2013) predicts that effects of interference on associative memory should be minimal because its hippocampal representation allows pattern separation even of highly similar information. In contrast, there should be strong interference effects on extra-hippocampally represented item memory. We tested this prediction in behavioral data from 3 experiments using continuous recognition paradigms. Given older adults' greater deficits in associative than item memory, we also compared younger and older adults to test whether this associative deficit extends to greater interference susceptibility in older adults' associative memory. Experiment 1 examined item-item associative memory with participants studying unrelated word pairs continuously intermixed with item (single words) and associative (intact vs. recombined pairs) recognition tests across interference-filled lags. Experiments 2 and 3 examined item-context (i.e., source) associative memory with participants studying words in different spatial positions continuously intermixed with source-monitoring tests (presented on top vs. on bottom vs. new?) across interference-filled lags (Experiment 3 controlling for delay/decay-based effects). In all experiments, item memory declined from the first lag on. In contrast, associative memory initially remained stable, with strong evidence for null effects of interference even in older adults, but showed some declines at later lags. The data supports Hardt et al.'s proposal of differential interference-based forgetting in item versus associative memory. The results further show that the age-related associative memory deficit does not extend to greater interference-based forgetting in older adults' associative memory. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

In 2025, psycholinguistic research has the benefit of large, high-quality datasets of human behavior, and massively-scalable metrics for variables of interest like frequency and association. This means we have more data than ever before to shed light on classic language processing phenomena like associative priming. But in order to build and test rigorous theories against this data, we also need computational modeling tools that can simulate cognitive mechanisms and generate quantitative predictions at the same scale. In this paper, we assemble one such case, adapting the ACT-R cognitive modeling framework to make use of association metrics derived from language model embeddings, in service of a scalable model of associative priming in the Lexical Decision Task. ACT-R implements a model of memory retrieval that can use itemwise predictors like frequency and association to predict task response times (RTs), via interpretable and meaningfully-parameterized components like spreading activation. But currently, ACT-R's spreading activation calculations rely on manually-coded similarity scores, which are labor-intensive and prone to inaccuracies, particularly for large vocabularies. In this study, we replace these hand-coded associations with cosine similarity scores derived from Word2Vec and BERT embeddings, thereby improving both scalability and predictive accuracy while retaining ACT-R's interpretability. We compare various versions of our model against observed human RTs from the Semantic Priming Project dataset, observing impressive item-wise prediction accuracy, and achieving the strongest alignment with a model where spreading activation is penalized via a scalable approximation of the classic “fan effect.” These findings provide a proof of concept for integrating embedding-based representations into algorithmic-level models of language processing. More than an insight into models of priming, we see this as a first step toward scalable and specific models of more complex phenomena.