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Cognition Aug 2024Eyes are active in memory recall and visual imagination, yet our grasp of the underlying qualities and factors of these internally coupled eye movements is limited. To...
Eyes are active in memory recall and visual imagination, yet our grasp of the underlying qualities and factors of these internally coupled eye movements is limited. To explore this, we studied 50 participants, examining how workload, spatial reference availability, and imagined movement direction influence internal coupling of eye movements. We designed a visuospatial working memory task in which participants mentally moved a black patch along a path within a matrix and each trial involved one step along this path (presented via speakers: up, down, left, or right). We varied workload by adjusting matrix size (3 × 3 vs. 5 × 5), manipulated availability of a spatial frame of reference by presenting either a blank screen (requiring participants to rely solely on their mental representation of the matrix) or spatial reference in the form of an empty matrix, and contrasted active task performance to two control conditions involving only active or passive listening. Our findings show that eye movements consistently matched the imagined movement of the patch in the matrix, not driven solely by auditory or semantic cues. While workload influenced pupil diameter, perceived demand, and performance, it had no observable impact on internal coupling. The availability of spatial reference enhanced coupling of eye movements, leading more frequent, precise, and resilient saccades against noise and bias. The absence of workload effects on coupled saccades in our study, in combination with the relatively high degree of coupling observed even in the invisible matrix condition, indicates that eye movements align with shifts in attention across both visually and internally represented information. This suggests that coupled eye movements are not merely strategic efforts to reduce workload, but rather a natural response to where attention is directed.
Topics: Humans; Memory, Short-Term; Adult; Male; Female; Young Adult; Space Perception; Eye Movements; Imagination; Visual Perception; Psychomotor Performance
PubMed: 38761645
DOI: 10.1016/j.cognition.2024.105815 -
Consciousness and Cognition Jul 2024People's memory for scenes has consequences, including for eyewitness testimony. Negative scenes may lead to a particular memory error, where narrowed scene boundaries...
People's memory for scenes has consequences, including for eyewitness testimony. Negative scenes may lead to a particular memory error, where narrowed scene boundaries lead people to recall being closer to a scene than they were. But boundary restriction-including attenuation of the opposite phenomenon boundary extension-has been difficult to replicate, perhaps because heightened arousal accompanying negative scenes, rather than negative valence itself, drives the effect. Indeed, in Green et al. (2019) arousal alone, conditioned to a particular neutral image category, increased boundary restriction for images in that category. But systematic differences between image categories may have driven these results, irrespective of arousal. Here, we clarify whether boundary restriction stems from the external arousal stimulus or image category differences. Presenting one image category (everyday-objects), half accompanied by arousal (Experiment 1), and presenting both neutral image categories (everyday-objects, nature), without arousal (Experiment 2), resulted in no difference in boundary judgement errors. These findings suggest that image features-including inherent valence, arousal, and complexity-are not sufficient to induce boundary restriction or reduce boundary extension for neutral images, perhaps explaining why boundary restriction is inconsistently demonstrated in the lab.
Topics: Humans; Arousal; Adult; Female; Young Adult; Male; Pattern Recognition, Visual; Mental Recall
PubMed: 38761426
DOI: 10.1016/j.concog.2024.103695 -
Cortex; a Journal Devoted To the Study... Jul 2024Despite the fact that attention undergoes protracted development, little is known about how it may support memory refinements in childhood and adolescence. Here, we...
Despite the fact that attention undergoes protracted development, little is known about how it may support memory refinements in childhood and adolescence. Here, we asked whether people differentially focus their attention on semantic or perceptual information over development during memory retrieval. First, we trained a multivoxel classifier to characterize whole-brain neural patterns reflecting semantic versus perceptual attention in a cued attention task. We then used this classifier to quantify how attention varied in a separate dataset in which children, adolescents, and adults retrieved autobiographical, semantic, and episodic memories. All age groups demonstrated a semantic attentional bias during memory retrieval, with significant age differences in this bias during the semantic task. Trials began with a preparatory picture cue followed by a retrieval question, which allowed us to ask whether attentional biases varied by trial period. Adults showed a semantic bias earlier during the picture cues, whereas adolescents showed this bias during the question. Adults and adolescents also engaged different brain regions-superior parietal cortex and ventral visual regions, respectively-during preparatory picture cues. Our results demonstrate that retrieval-related attention undergoes refinement beyond childhood. These findings suggest that alongside expanding semantic knowledge, attention-related changes may support the maturation of factual knowledge retrieval.
Topics: Humans; Adolescent; Female; Attention; Male; Mental Recall; Young Adult; Child; Adult; Semantics; Cues; Magnetic Resonance Imaging; Brain; Memory, Episodic; Brain Mapping; Memory
PubMed: 38761418
DOI: 10.1016/j.cortex.2024.04.012 -
Scientific Reports May 2024Several lines of evidence demonstrate that the brain histaminergic system is fundamental for cognitive processes and the expression of memories. Here, we investigated...
Several lines of evidence demonstrate that the brain histaminergic system is fundamental for cognitive processes and the expression of memories. Here, we investigated the effect of acute silencing or activation of histaminergic neurons in the hypothalamic tuberomamillary nucleus (TMN neurons) in vivo in both sexes in an attempt to provide direct and causal evidence of the necessary role of these neurons in recognition memory formation and retrieval. To this end, we compared the performance of mice in two non-aversive and non-rewarded memory tests, the social and object recognition memory tasks, which are known to recruit different brain circuitries. To directly establish the impact of inactivation or activation of TMN neurons, we examined the effect of specific chemogenetic manipulations during the formation (acquisition/consolidation) or retrieval of recognition memories. We consistently found that acute chemogenetic silencing of TMN neurons disrupts the formation or retrieval of both social and object recognition memory in males and females. Conversely, acute chemogenetic activation of TMN neurons during training or retrieval extended social memory in both sexes and object memory in a sex-specific fashion. These results suggest that the formation or retrieval of recognition memory requires the tonic activity of histaminergic neurons and strengthen the concept that boosting the brain histaminergic system can promote the retrieval of apparently lost memories.
Topics: Animals; Female; Male; Neurons; Mice; Recognition, Psychology; Histamine; Mice, Inbred C57BL; Hypothalamic Area, Lateral; Mental Recall
PubMed: 38760416
DOI: 10.1038/s41598-024-61998-0 -
ENeuro May 2024The ability to remember changes in the surroundings is fundamental for daily life. It has been proposed that novel events producing dopamine release in the hippocampal...
The ability to remember changes in the surroundings is fundamental for daily life. It has been proposed that novel events producing dopamine release in the hippocampal CA1 region could modulate spatial memory formation. However, the role of hippocampal dopamine increase on weak or strong spatial memories remains unclear. We show that male mice exploring two objects located in a familiar environment for 5 min created a short-term memory (weak) that cannot be retrieved 1 d later, whereas 10 min exploration created a long-term memory (strong) that can be retrieved 1 d later. Remarkably, hippocampal dopamine elevation during the encoding of weak object location memories (OLMs) allowed their retrieval 1 d later but dopamine elevation during the encoding of strong OLMs promoted the preference for a familiar object location over a novel object location after 24 h. Moreover, dopamine uncaging after the encoding of OLMs did not have effect on weak memories whereas on strong memories diminished the exploration of the novel object location. Additionally, hippocampal dopamine elevation during the retrieval of OLMs did not allow the recovery of weak memories and did not affect the retrieval of strong memory traces. Finally, dopamine elevation increased hippocampal theta oscillations, indicating that dopamine promotes the recurrent activation of specific groups of neurons. Our experiments demonstrate that hippocampal dopaminergic modulation during the encoding of OLMs depends on memory strength indicating that hyperdopaminergic levels that enhance weak experiences could compromise the normal storage of strong memories.
Topics: Animals; Dopamine; Male; Spatial Memory; Hippocampus; Mice, Inbred C57BL; Mice; Theta Rhythm; Exploratory Behavior; Mental Recall; Memory, Long-Term; Memory, Short-Term
PubMed: 38755011
DOI: 10.1523/ENEURO.0469-23.2024 -
PloS One 2024The prestige theory of evolution states that our memory has an intrinsic bias to memorize information from someone of prestige. However, the evidence for information...
The prestige theory of evolution states that our memory has an intrinsic bias to memorize information from someone of prestige. However, the evidence for information recall is mainly focused on content bias. Considering that the prestige bias can be advantageous in selecting information in contexts of uncertainty, this study assessed whether, in the scenario of the COVID-19 pandemic, the prestige bias would be favored over other models that do not possess the prestige spirit characteristics. The study was conducted through an online experiment, where participants were subjected to reading fictitious text, followed by a surprise recollection. Data were analyzed using a generalized linear mixed model, Poisson family, and logistic regression. The results showed that prestige is only prioritized in the recall due to the family model and does not present any difference from the other models tested. However, it influenced the recall of specific information, suggesting its role as a factor of cultural attraction. Furthermore, we observed that trust in science-oriented profiles can influence the recall of information during a health crisis. Finally, this study highlights the complexity of the functioning of the human mind and how several factors can act simultaneously in the recall of information.
Topics: Humans; COVID-19; Female; Male; Mental Recall; Adult; Pandemics; SARS-CoV-2; Young Adult; Trust; Bias
PubMed: 38753598
DOI: 10.1371/journal.pone.0303512 -
PloS One 2024Episodic memory describes the conscious reimagining of our memories and is often considered to be a uniquely human ability. As these phenomenological components are...
Episodic memory describes the conscious reimagining of our memories and is often considered to be a uniquely human ability. As these phenomenological components are embedded within its definition, major issues arise when investigating the presence of episodic memory in non-human animals. Importantly, however, when we as humans recall a specific experience, we may remember details from that experience that were inconsequential to our needs, thoughts, or desires at that time. This 'incidental' information is nevertheless encoded automatically as part of the memory and is subsequently recalled within a holistic representation of the event. The incidental encoding and unexpected question paradigm represents this characteristic feature of human episodic memory and can be employed to investigate memory recall in non-human animals. However, without evidence for the associated phenomenology during recall, this type of memory is termed 'episodic-like memory'. Using this approach, we tested seven Eurasian jays (Garrulus glandarius) on their ability to use incidental visual information (associated with observed experimenter made 'caches') to solve an unexpected memory test. The birds performed above chance levels, suggesting that Eurasian jays can encode, retain, recall, and access incidental visual information within a remembered event, which is an ability indicative of episodic memory in humans.
Topics: Animals; Memory, Episodic; Mental Recall; Passeriformes; Male; Female; Humans
PubMed: 38748646
DOI: 10.1371/journal.pone.0301298 -
Cerebral Cortex (New York, N.Y. : 1991) May 2024Sleep supports memory consolidation via the reactivation of newly formed memory traces. One way to investigate memory reactivation in sleep is by exposing the sleeping...
Sleep supports memory consolidation via the reactivation of newly formed memory traces. One way to investigate memory reactivation in sleep is by exposing the sleeping brain to auditory retrieval cues; a paradigm known as targeted memory reactivation. To what extent the acoustic properties of memory cues influence the effectiveness of targeted memory reactivation, however, has received limited attention. We addressed this question by exploring how verbal and non-verbal memory cues affect oscillatory activity linked to memory reactivation in sleep. Fifty-one healthy male adults learned to associate visual stimuli with spoken words (verbal cues) and environmental sounds (non-verbal cues). Subsets of the verbal and non-verbal memory cues were then replayed during sleep. The voice of the verbal cues was either matched or mismatched to learning. Memory cues (relative to unheard control cues) prompted an increase in theta/alpha and spindle power, which have been heavily implicated in sleep-associated memory processing. Moreover, verbal memory cues were associated with a stronger increase in spindle power than non-verbal memory cues. There were no significant differences between the matched and mismatched verbal cues. Our findings suggest that verbal memory cues may be most effective for triggering memory reactivation in sleep, as indicated by an amplified spindle response.
Topics: Humans; Male; Cues; Young Adult; Sleep; Adult; Mental Recall; Electroencephalography; Memory Consolidation; Acoustic Stimulation; Brain; Photic Stimulation; Brain Waves
PubMed: 38745557
DOI: 10.1093/cercor/bhae183 -
PloS One 2024Suicide-related media content has preventive or harmful effects depending on the specific content. Proactive media screening for suicide prevention is hampered by the...
Suicide-related media content has preventive or harmful effects depending on the specific content. Proactive media screening for suicide prevention is hampered by the scarcity of machine learning approaches to detect specific characteristics in news reports. This study applied machine learning to label large quantities of broadcast (TV and radio) media data according to media recommendations reporting suicide. We manually labeled 2519 English transcripts from 44 broadcast sources in Oregon and Washington, USA, published between April 2019 and March 2020. We conducted a content analysis of media reports regarding content characteristics. We trained a benchmark of machine learning models including a majority classifier, approaches based on word frequency (TF-IDF with a linear SVM) and a deep learning model (BERT). We applied these models to a selection of more simple (e.g., focus on a suicide death), and subsequently to putatively more complex tasks (e.g., determining the main focus of a text from 14 categories). Tf-idf with SVM and BERT were clearly better than the naive majority classifier for all characteristics. In a test dataset not used during model training, F1-scores (i.e., the harmonic mean of precision and recall) ranged from 0.90 for celebrity suicide down to 0.58 for the identification of the main focus of the media item. Model performance depended strongly on the number of training samples available, and much less on assumed difficulty of the classification task. This study demonstrates that machine learning models can achieve very satisfactory results for classifying suicide-related broadcast media content, including multi-class characteristics, as long as enough training samples are available. The developed models enable future large-scale screening and investigations of broadcast media.
Topics: Humans; Machine Learning; Mass Media; Suicide; Suicide Prevention; Oregon; Washington; Deep Learning
PubMed: 38743759
DOI: 10.1371/journal.pone.0300917 -
PloS One 2024Predicting neurocognitive deficits using complex auditory assessments could change how cognitive dysfunction is identified, and monitored over time. Detecting cognitive...
IMPORTANCE
Predicting neurocognitive deficits using complex auditory assessments could change how cognitive dysfunction is identified, and monitored over time. Detecting cognitive impairment in people living with HIV (PLWH) is important for early intervention, especially in low- to middle-income countries where most cases exist. Auditory tests relate to neurocognitive test results, but the incremental predictive capability beyond demographic factors is unknown.
OBJECTIVE
Use machine learning to predict neurocognitive deficits, using auditory tests and demographic factors.
SETTING
The Infectious Disease Center in Dar es Salaam, Tanzania.
PARTICIPANTS
Participants were 939 Tanzanian individuals from Dar es Salaam living with and without HIV who were part of a longitudinal study. Patients who had only one visit, a positive history of ear drainage, concussion, significant noise or chemical exposure, neurological disease, mental illness, or exposure to ototoxic antibiotics (e.g., gentamycin), or chemotherapy were excluded. This provided 478 participants (349 PLWH, 129 HIV-negative). Participant data were randomized to training and test sets for machine learning.
MAIN OUTCOME(S) AND MEASURE(S)
The main outcome was whether auditory variables combined with relevant demographic variables could predict neurocognitive dysfunction (defined as a score of <26 on the Kiswahili Montreal Cognitive Assessment) better than demographic factors alone. The performance of predictive machine learning algorithms was primarily evaluated using the area under the receiver operational characteristic curve. Secondary metrics for evaluation included F1 scores, accuracies, and the Youden's indices for the algorithms.
RESULTS
The percentage of individuals with cognitive deficits was 36.2% (139 PLWH and 34 HIV-negative). The Gaussian and kernel naïve Bayes classifiers were the most predictive algorithms for neurocognitive impairment. Algorithms trained with auditory variables had average area under the curve values of 0.91 and 0.87, F1 scores (metric for precision and recall) of 0.81 and 0.76, and average accuracies of 86.3% and 81.9% respectively. Algorithms trained without auditory variables as features were statistically worse (p < .001) in both the primary measure of area under the curve (0.82/0.78) and the secondary measure of accuracy (72.3%/74.5%) for the Gaussian and kernel algorithms respectively.
CONCLUSIONS AND RELEVANCE
Auditory variables improved the prediction of cognitive function. Since auditory tests are easy-to-administer and often naturalistic tasks, they may offer objective measures or predictors of neurocognitive performance suitable for many global settings. Further research and development into using machine learning algorithms for predicting cognitive outcomes should be pursued.
Topics: Humans; Machine Learning; Male; Female; Adult; Cognitive Dysfunction; Middle Aged; HIV Infections; Tanzania; Longitudinal Studies; Neuropsychological Tests
PubMed: 38743715
DOI: 10.1371/journal.pone.0302902