Deep Semantic Processing Research Articles

Chinese nouns are mass nouns: An information-theoretic computational proof

The mass–count distinction in Mandarin Chinese has been heatedly debated in linguistics. Previous research investigated the mass–count distinction primarily through qualitative methods. Our study applied mutual information and created three variation conditions to explore the relationship between Chinese nouns and the individuation function of classifiers. Furthermore, we examined the mass–count distinction by quantitatively analyzing 1,000 instances of Num–CL–N (numeral–classifier–noun) structures. The computational results indicate that the individuation function of classifiers is influenced by noun homogeneity. Moreover, we argue that Chinese nouns exhibit an inclination for homogeneity and the deep semantic processing of nouns is similar to classes or sets, providing evidence for the broad mass noun hypothesis and the collective-name hypothesis in the philosophy of language.

Vulnerability to semantic and phonological interference in normal aging and amnestic mild cognitive impairment (aMCI).

To determine whether the increased vulnerability to semantic interference previously observed in amnestic mild cognitive impairment (aMCI) is specifically associated with semantic material or if it also affects other types of material, suggesting generalized executive and inhibitory impairment. Seventy-two participants divided into two groups (33 aMCI, 39 normal control [NC]) matched for age and education were included. They completed a comprehensive neuropsychological examination, the French version of the Loewenstein Acevedo Scale for Semantic Interference and Learning (LASSI-L; semantic interference test), and a homologous experimental phonological test, the phonological interference and learning test. Independent sample t tests, mixed analysis of variance (ANOVA), and analysis of covariance (ANCOVA) on memory and interference scores were conducted to compare memory and interference in both conditions for both groups. For memory scores, results revealed significant main effects of group (NC > aMCI) and condition (semantic > phonological) and significant interactions (poorer performance in the semantic condition for aMCI). aMCI committed more phonological false recognition errors, were disproportionately more vulnerable to retroactive semantic interference, and showed a higher percentage of intrusion errors associated with proactive semantic interference than NC. To our knowledge, this is the first study to compare vulnerability to interference in aMCI and normal aging with two similarly designed semantic and phonological word list learning tasks. Taken together, our results suggest that aMCI present with broad difficulties in source memory and inhibition, but that impaired deep semantic processing results in additional semantic intrusion errors during proactive interference and impacts their ability to show good recall after an interference list (greater semantic retroactive interference). Results are discussed according to the level-of-processing and activation/monitoring theories. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Flexible and fine-grained simulation of speed in language processing.

According to the embodied cognition theory, language comprehension is achieved through mental simulation. This account is supported by a number of studies reporting action simulations during language comprehension. However, which details of sensory-motor experience are included in these simulations is still controversial. Here, three experiments were carried out to examine the simulation of speed in action language comprehension. Experiment 1 adopted a lexical decision task and a semantic similarity judgment task on isolated fast and slow action verbs. It has been shown that fast action verbs were processed significantly faster than slow action verbs when deep semantic processing is required. Experiment 2 and Experiment 3 investigated the contextual influence on the simulation of speed, showing that the processing of verbs, either depicting fast actions or neutral actions, would be slowed down when embedded in the slow action sentences. These experiments together demonstrate that the fine-gained information, speed, is an important part of action representation and can be simulated but may not in an automatic way. Moreover, the speed simulation is flexible and can be modulated by the context.

When does intent matter for memory? Bridging perspectives with Craik.

In his commentary, Craik (see record 2023-42323-002) argued that while intentional remembering might be effective for some populations and memory tasks, these are the exception, and that intent will not benefit memory if incidental encoding induces optimal processing. While we agree on many points, we maintain that in most situations the processes induced by the intention to remember are more effective than those induced by deep semantic processing alone. We show that effects of intent appear with a variety of tasks such as free recall, cued recall, source memory, item recognition, in both mixed and pure lists, and when studying individual words, word pairs, or word-image associations. Thus, the beneficial effects of intent generalize over tasks, list-compositions, and study materials. There are also little individual differences in the effect of intent in healthy young adults-most participants (86% out of 336 participants over six experiments) show a beneficial effect. We review evidence that the intent to remember strengthens item-context bindings in episodic memory, but that such effects could be masked and not measurable in subsequent memory tests, unless intrusions are taken into account. We agree that in principle incidental encoding could induce optimal processing, but we do not find the existing evidence convincing. We provide additional novel data that directly addresses Craik's (2023) concerns and we propose ways to further investigate how intention enhances memory. We conclude with a joint statement, coauthored by Craik and ourselves, that synthesizes our converging perspectives and current understanding of the impact of intent on memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Establishing a causal role for left ventrolateral prefrontal cortex in value-directed memory encoding with high-definition transcranial direct current stimulation

One critical approach for promoting the efficiency of memory is to adopt selective encoding strategies to prioritize more valuable information. Past neuroimaging studies have shown that value-directed modulation of verbal memory depends heavily on the engagement of left-lateralized semantic processing regions, particularly in the ventrolateral prefrontal cortex (VLPFC). In the present study, we used high-definition transcranial direct current stimulation (HD-tDCS) to seek evidence for a causal role of left VLPFC in supporting the memory advantage for high-value items. Three groups of healthy young adult participants were presented with lists of words to remember, with each word accompanied by an arbitrarily assigned point value. During the first session, all participants received sham stimulation as they encoded five lists of 30 words each. Two of these lists were immediately tested with free recall, with feedback given to allow participants to develop metacognitive insight and strategies to maximize their point total. The second session had the exact same structure as the first, but the groups differed in whether they received continued sham stimulation (N = 22) or anodal stimulation of the left VLPFC (N = 21) or right VLPFC (N = 20). Those lists not tested with immediate recall were tested with recognition judgments after a one-day delay. Since no brain stimulation was applied during this Day 2 test, any performance differences can be attributed to the effects of stimulation on Day 1 encoding processes. Anodal stimulation of left VLPFC significantly boosted participants’ memory encoding selectivity. In comparison, no such effect was seen in participants who received right VLPFC or sham stimulation. Estimates of recollection- and familiarity-based responding revealed that left VLPFC stimulation specifically amplified the effects of item value on recollection. These results demonstrate a causal role for left VLPFC in the implementation of selective value-directed encoding strategies, putatively by boosting deep semantic processing of high-value words. Our findings also provide further evidence on the hemispheric lateralization of value-directed verbal memory encoding.

The depth of semantic processing modulates cross-language pattern similarity in Chinese-English bilinguals.

Previous studies have investigated factors related to the degree of cross-language overlap in brain activations in bilinguals/multilinguals. However, it is still unclear whether and how the depth of semantic processing (a critical task-related factor) affects the neural pattern similarity between native and second languages. To address this question, 26 Chinese-English bilinguals were scanned with fMRI while performing a word naming task (i.e., a task with shallow semantic processing) and a semantic judgment task (i.e., a task with deep semantic processing) in both native and second languages. Based on three sets of representational similarity analysis (whole brain, ROI-based, and within-language vs. cross-language semantic representation), we found that select regions in the reading brain network showed higher cross-language pattern similarity and higher cross-language semantic representations during deep semantic processing than during shallow semantic processing. These results suggest that compared to shallow semantic processing, deep semantic processing may lead to greater language-independent processing (i.e., cross-language semantic representation) and cross-language pattern similarity, and provide direct quantitative neuroimaging evidence for cognitive models of bilingual lexical memory.

Semantic feedback processing mechanism of the enactment effect: Evidence from event-related potentials.

The enactment effect refers to a phenomenon in which the memory performance for action phrases is enhanced by performing the described action (e.g., sharpen a pencil) compared with simply reading the action phrase. This produced effect can result in improved motor processing. This study investigated the contribution of semantic integration to the enactment effect by contrasting well-integrated phrases, such as "blow up the balloon," with poorly integrated phrases, such as "sew the toothpick," and analysing the N400 component of event-related potentials (ERPs). The subjects encoded action phrases with different degrees of semantic integration by either pretending to perform or reading action phrases. They then completed a phrase recognition test, while electroencephalographic signals were simultaneously recorded. The behavioural results showed that semantic integration improved memory performance under the motor encoding condition but not under the verbal encoding condition. The ERP results revealed that, regardless of whether it was an old (memorised) or new (distractor) phrase, a larger N400 component was elicited under the motor encoding condition than under the verbal encoding condition. In the motor encoding condition, poorly integrated phrases elicited a larger N400 component than well-integrated phrases; in the verbal encoding condition, this effect was not observed. The N400 effect associated with semantic processing was enhanced by semantic integration under the motor encoding condition rather than the verbal encoding condition. These results supported a deep semantic processing mechanism under the motor encoding condition, and a semantic feedback processing mechanism for the enactment effect was partially supported.

Effects of distinctiveness and memory on lateralized and unlateralized brain-electrical activity during visual word encoding

The present study investigated a recently introduced left-lateralized component in the event-related potential (ERP), the posterior semantic asymmetry (PSA), in the context of an isolation paradigm. The PSA is a relative negativity that is most pronounced at temporoparietal electrodes, peaks around 300 ms, and is assumed to reflect early semantic processing of visual words. A free-recall, word-list-learning paradigm was conducted. The learning list comprised two stimuli which were physically isolated from the other stimuli (by different font size or different typeface). The typical behavioral isolation effect with higher recall for isolated stimuli was observed. Furthermore, ERP effects of stimulus type and subsequent memory were analyzed. A left-lateralized negativity that matched the topography of the PSA but occurred somewhat later showed an effect of stimulus distinctiveness, with increased amplitudes for isolates, thus suggesting their deeper semantic processing. However, PSA amplitude did not predict subsequent recall. Unlateralized ERPs replicated previous findings of a greater late frontal positivity during elaborated encoding of both isolated stimuli and subsequently recalled stimuli. This recall effect was greater for isolated than standard stimuli. We argue that physical distinctiveness during encoding facilitates recall to the extent that it promotes the frontally-mediated processes that predict better recall in general.

Attenuation of deep semantic processing during mind wandering: an event-related potential study.

Although much research shows that early sensory and attentional processing is affected by mind wandering, the effect of mind wandering on deep (i.e. semantic) processing is relatively unexplored. To investigate this relation, we recorded event-related potentials as participants studied English-Spanish word pairs, one at a time, while being intermittently probed for whether they were 'on task' or 'mind wandering'. Both perceptual processing, indexed by the P2 component, and deep processing, indexed by a late, sustained slow wave maximal at parietal electrodes, was attenuated during periods preceding participants' mind wandering reports. The pattern when participants were on task, rather than mind wandering, is similar to the subsequent memory or difference in memory effect. These results support previous findings of sensory attenuation during mind wandering, and extend them to a long-duration slow wave by suggesting that the deeper and more sustained levels of processing are also disrupted.

Aberrant prefrontal beta oscillations predict episodic memory encoding deficits in schizophrenia.

Verbal episodic memory is one of the core cognitive functions affected in patients with schizophrenia (SZ). Although this verbal memory impairment in SZ is a well-known finding, our understanding about its underlying neurophysiological mechanisms is rather scarce. Here we address this issue by recording brain oscillations during a memory task in a sample of healthy controls and patients with SZ. Brain oscillations represent spectral fingerprints of specific neurocognitive operations and are therefore a promising tool to identify neurocognitive mechanisms that are affected by SZ. Healthy controls showed a prominent suppression of left prefrontal beta oscillatory activity during successful memory formation, which replicates several previous oscillatory memory studies. In contrast, patients failed to exhibit such a left prefrontal beta power suppression. Utilizing a new topographical pattern similarity approach, we further demonstrate that the degree of similarity between a patient's beta power decrease to that of the controls reliably predicted memory performance. This relationship between beta power decreases and memory was such that the patients' memory performance improved as they showed a more similar topographical beta desynchronization pattern compared to that of healthy controls. Together, these findings support left prefrontal beta desynchronization as the spectral fingerprint of verbal episodic memory formation, likely indicating deep semantic processing of verbal material. These findings also demonstrate that left prefrontal beta power suppression (or lack thereof) during memory encoding are a reliable biomarker for the observed encoding impairments in SZ in verbal memory.

Multi-talker background and semantic priming effect.

The reported studies have aimed to investigate whether informational masking in a multi-talker background relies on semantic interference between the background and target using an adapted semantic priming paradigm. In 3 experiments, participants were required to perform a lexical decision task on a target item embedded in backgrounds composed of 1–4 voices. These voices were Semantically Consistent (SC) voices (i.e., pronouncing words sharing semantic features with the target) or Semantically Inconsistent (SI) voices (i.e., pronouncing words semantically unrelated to each other and to the target). In the first experiment, backgrounds consisted of 1 or 2 SC voices. One and 2 SI voices were added in Experiments 2 and 3, respectively. The results showed a semantic priming effect only in the conditions where the number of SC voices was greater than the number of SI voices, suggesting that semantic priming depended on prime intelligibility and strategic processes. However, even if backgrounds were composed of 3 or 4 voices, reducing intelligibility, participants were able to recognize words from these backgrounds, although no semantic priming effect on the targets was observed. Overall this finding suggests that informational masking can occur at a semantic level if intelligibility is sufficient. Based on the Effortfulness Hypothesis, we also suggest that when there is an increased difficulty in extracting target signals (caused by a relatively high number of voices in the background), more cognitive resources were allocated to formal processes (i.e., acoustic and phonological), leading to a decrease in available resources for deeper semantic processing of background words, therefore preventing semantic priming from occurring.

Arabic web pages clustering and annotation using semantic class features

To effectively manage the great amount of data on Arabic web pages and to enable the classification of relevant information are very important research problems. Studies on sentiment text mining have been very limited in the Arabic language because they need to involve deep semantic processing. Therefore, in this paper, we aim to retrieve machine-understandable data with the help of a Web content mining technique to detect covert knowledge within these data. We propose an approach to achieve clustering with semantic similarities. This approach comprises integrating k-means document clustering with semantic feature extraction and document vectorization to group Arabic web pages according to semantic similarities and then show the semantic annotation. The document vectorization helps to transform text documents into a semantic class probability distribution or semantic class density. To reach semantic similarities, the approach extracts the semantic class features and integrates them into the similarity weighting schema. The quality of the clustering result has evaluated the use of the purity and the mean intra-cluster distance (MICD) evaluation measures. We have evaluated the proposed approach on a set of common Arabic news web pages. We have acquired favorable clustering results that are effective in minimizing the MICD, expanding the purity and lowering the runtime.

Event-related brain potentials differentiate three types of emotional words categorized from linguistic perspective

Abstract The present study investigated the differences of processing three types of emotional words categorized into Affect, Judgment and Appreciation according to the linguistic Appraisal Theory. Behavioral and ERP responses were recorded as participants performed the category decision task, which required them to identify whether a word belonged to Affect, Judgment or Appreciation. The behavioral results showed significant main effects and interaction of category and valence. The category and valence effects in ERPs were evident within the time windows of N400 and late positive complex (LPC). To be specific, under negative condition, the affect words revealed a facilitated processing associated with the least negative N400 and an elaborate processing with the largest LPC amplitude, while the appreciation words elicited the most enhanced N400 and the smallest LPC amplitude. The ERP data indicate that emotional words of different categories may be processed differently when deep semantic processing was required.

Value-based modulation of memory encoding involves strategic engagement of fronto-temporal semantic processing regions

A number of prior fMRI studies have focused on the ways in which the midbrain dopaminergic reward system coactivates with hippocampus to potentiate memory for valuable items. However, another means by which people could selectively remember more valuable to-be-remembered items is to be selective in their use of effective but effortful encoding strategies. To broadly examine the neural mechanisms of value on subsequent memory, we used fMRI to assess how differences in brain activity at encoding as a function of value relate to subsequent free recall for words. Each word was preceded by an arbitrarily assigned point value, and participants went through multiple study-test cycles with feedback on their point total at the end of each list, allowing for sculpting of cognitive strategies. We examined the correlation between value-related modulation of brain activity and participants' selectivity index, which measures how close participants were to their optimal point total, given the number of items recalled. Greater selectivity scores were associated with greater differences in the activation of semantic processing regions, including left inferior frontal gyrus and left posterior lateral temporal cortex, during the encoding of high-value words relative to low-value words. Although we also observed value-related modulation within midbrain and ventral striatal reward regions, our fronto-temporal findings suggest that strategic engagement of deep semantic processing may be an important mechanism for selectively encoding valuable items.

Mechanisms of short-term false memory formation

False memories are the erroneous recollection of events that did not actually occur. False memories have been broadly investigated within the domain of long-term memory, while studies involving short-term memory are less common and provide a far less detailed ‘picture’ of this phenomenon. We tested participants in a short-term memory task involving lists of four semantically related words that had to be matched with a probe word. Crucially, the probe word could be one of the four words of the list, it could be semantically related to them, or it could be semantically unrelated to the list. Participants had to decide whether the probe was in the list. To this task we added articulatory suppression to impair rehearsal, concurrent material to remember, and changes to the visual appearance of the probes to assess the mechanism involved in short-term memory retrieval. The results showed that, similarly to the studies on long-term memory, false memories emerged more frequently for probes semantically related to the list and when rehearsal was impaired by concurrent material. The visual appearance of the stimuli did not play an important role. This set of results suggests that deep semantic processing, rather than only superficial visual processing, is taking place within a few seconds from the presentation of the probes.

Testing alters brain activity during subsequent restudy: Evidence for test-potentiated encoding

Mixed testing/studying lead to better memory retention compared to repeated study only. A potentiating influence of tests on encoding, particularly during restudy of non-retrieved items, may contribute to this effect. This study investigated whether and how testing affects brain activity during subsequent restudy of Swahili–Swedish word pairs after a cued-recall test. Item-events during fMRI were categorized according to history (tested/studied only) and recall outcome at prescan and postscan tests. Activity was higher for tested compared to studied-only items in anterior insula, orbital parts of inferior frontal gyrus and hippocampus, and lower in regions implicated in the default network, such as precuneus, supramarginal gyrus and the posterior middle cingulate. Findings are discussed in terms of top-down biasing of attention to tested items with concomitant deactivation of regions in the default network. Increased/focused attention to tested items during restudy may lead to test-potentiated encoding via deeper semantic processing and increased associative binding.

Adaptive memory: The influence of sleep and wake delay on the survival-processing effect

Processing items in terms of their survival value leads to superior memory relative to many deep (semantic) processing tasks. To date, such survival processing has been investigated with short delay intervals only, ignoring possible effects of longer wake and sleep delay. In this study, subjects performed orienting tasks that induced survival or deep (semantic) processing of single items. A surprise memory test was administered after a short delay or a delay of 12 hours that included either sleep or wake; a cued-recall test was conducted in Experiment 1, and an item-recognition test in Experiment 2. Survival-processing effects were present regardless of delay, and their size was not influenced by delay interval. While wake delay reduced memory for both item types, sleep compared to wake enhanced their memory. These results suggest that the survival-processing effect is fully maintained across longer delay, regardless of whether the interval is filled with wake or sleep.

Friendly drug-dealers and terrifying puppies: Affective primacy can attenuate the N400 effect in emotional discourse contexts

Words that are semantically congruous with their preceding discourse context are easier to process than words that are semantically incongruous with their context. This facilitation of semantic processing is reflected by an attenuation of the N400 event-related potential (ERP). We asked whether this was true of emotional words in emotional contexts where discourse congruity was conferred through emotional valence. ERPs were measured as 24 participants read two-sentence scenarios with critical words that varied by emotion (pleasant, unpleasant, or neutral) and congruity (congruous or incongruous). Semantic predictability, constraint, and plausibility were comparable across the neutral and emotional scenarios. As expected, the N400 was smaller to neutral words that were semantically congruous (vs. incongruous) with their neutral discourse context. No such N400 congruity effect was observed on emotional words following emotional discourse contexts. Rather, the amplitude of the N400 was small to all emotional words (pleasant and unpleasant), regardless of whether their emotional valence was congruous with the valence of their emotional discourse context. However, consistent with previous studies, the emotional words produced a larger late positivity than did the neutral words. These data suggest that comprehenders bypassed deep semantic processing of valence-incongruous emotional words within the N400 time window, moving rapidly on to evaluate the words' motivational significance.

Auditory cortical function during verbal episodic memory encoding in Alzheimer's disease

Episodic memory encoding of a verbal message depends upon initial registration, which requires sustained auditory attention followed by deep semantic processing of the message. Motivated by previous data demonstrating modulation of auditory cortical activity during sustained attention to auditory stimuli, we investigated the response of the human auditory cortex during encoding of sentences to episodic memory. Subsequently, we investigated this response in patients with mild cognitive impairment (MCI) and probable Alzheimer's disease (pAD). Using functional magnetic resonance imaging, 31 healthy participants were studied. The response in 18 MCI and 18 pAD patients was then determined, and compared to 18 matched healthy controls. Subjects heard factual sentences, and subsequent retrieval performance indicated successful registration and episodic encoding. The healthy subjects demonstrated that suppression of auditory cortical responses was related to greater success in encoding heard sentences; and that this was also associated with greater activity in the semantic system. In contrast, there was reduced auditory cortical suppression in patients with MCI, and absence of suppression in pAD. Administration of a central cholinesterase inhibitor (ChI) partially restored the suppression in patients with pAD, and this was associated with an improvement in verbal memory. Verbal episodic memory impairment in AD is associated with altered auditory cortical function, reversible with a ChI. Although these results may indicate the direct influence of pathology in auditory cortex, they are also likely to indicate a partially reversible impairment of feedback from neocortical systems responsible for sustained attention and semantic processing.

The relationship between level of processing and hippocampal–cortical functional connectivity during episodic memory formation in humans

New episodic memory traces represent a record of the ongoing neocortical processing engaged during memory formation (encoding). Thus, during encoding, deep (semantic) processing typically establishes more distinctive and retrievable memory traces than does shallow (perceptual) processing, as assessed by later episodic memory tests. By contrast, the hippocampus appears to play a processing-independent role in encoding, because hippocampal lesions impair encoding regardless of level of processing. Here, we clarified the neural relationship between processing and encoding by examining hippocampal-cortical connectivity during deep and shallow encoding. Participants studied words during functional magnetic resonance imaging and freely recalled these words after distraction. Deep study processing led to better recall than shallow study processing. For both levels of processing, successful encoding elicited activations of bilateral hippocampus and left prefrontal cortex, and increased functional connectivity between left hippocampus and bilateral medial prefrontal, cingulate and extrastriate cortices. Successful encoding during deep processing was additionally associated with increased functional connectivity between left hippocampus and bilateral ventrolateral prefrontal cortex and right temporoparietal junction. In the shallow encoding condition, on the other hand, pronounced functional connectivity increases were observed between the right hippocampus and the frontoparietal attention network activated during shallow study processing. Our results further specify how the hippocampus coordinates recording of ongoing neocortical activity into long-term memory, and begin to provide a neural explanation for the typical advantage of deep over shallow study processing for later episodic memory.