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PloS One 2024Semantic memory representations are generally well maintained in aging, whereas semantic control is thought to be more affected. To explain this phenomenon, this study...
Semantic memory representations are generally well maintained in aging, whereas semantic control is thought to be more affected. To explain this phenomenon, this study tested the predictions of the Compensation-Related Utilization of Neural Circuits Hypothesis (CRUNCH), focusing on task demands in aging as a possible framework. The CRUNCH effect would manifest itself in semantic tasks through a compensatory increase in neural activation in semantic control network regions but only up to a certain threshold of task demands. This study compares 39 younger (20-35 years old) with 39 older participants (60-75 years old) in a triad-based semantic judgment task performed in an fMRI scanner while manipulating task demand levels (low versus high) through semantic distance. In line with the CRUNCH predictions, differences in neurofunctional activation and behavioral performance (accuracy and response times) were expected in younger versus older participants in the low- versus high-demand conditions, which should be manifested in semantic control Regions of Interest (ROIs). Our older participants had intact behavioral performance, as proposed in the literature for semantic memory tasks (maintained accuracy and slower response times (RTs)). Age-invariant behavioral performance in the older group compared to the younger one is necessary to test the CRUNCH predictions. The older adults were also characterized by high cognitive reserve, as our neuropsychological tests showed. Our behavioral results confirmed that our task successfully manipulated task demands: error rates, RTs and perceived difficulty increased with increasing task demands in both age groups. We did not find an interaction between age group and task demand, or a statistically significant difference in activation between the low- and high-demand conditions for either RTs or accuracy. As for brain activation, we did not find the expected age group by task demand interaction, or a significant main effect of task demand. Overall, our results are compatible with some neural activation in the semantic network and the semantic control network, largely in frontotemporoparietal regions. ROI analyses demonstrated significant effects (but no interactions) of task demand in the left and right inferior frontal gyrus, the left posterior middle temporal gyrus, the posterior inferior temporal gyrus and the prefrontal gyrus. Overall, our test did not confirm the CRUNCH predictions.
Topics: Humans; Magnetic Resonance Imaging; Adult; Middle Aged; Aged; Male; Female; Semantics; Aging; Memory; Young Adult; Reaction Time; Brain Mapping; Nerve Net; Brain; Pre-Registration Publication
PubMed: 38917084
DOI: 10.1371/journal.pone.0289384 -
Frontiers in Plant Science 2024Canopy temperature (CT) is often interpreted as representing leaf activity traits such as photosynthetic rates, gas exchange rates, or stomatal conductance. This...
Canopy temperature (CT) is often interpreted as representing leaf activity traits such as photosynthetic rates, gas exchange rates, or stomatal conductance. This interpretation is based on the observation that leaf activity traits correlate with transpiration which affects leaf temperature. Accordingly, CT measurements may provide a basis for high throughput assessments of the productivity of wheat canopies during early grain filling, which would allow distinguishing functional from dysfunctional stay-green. However, whereas the usefulness of CT as a fast surrogate measure of sustained vigor under soil drying is well established, its potential to quantify leaf activity traits under high-yielding conditions is less clear. To better understand sensitivity limits of CT measurements under high yielding conditions, we generated within-genotype variability in stay-green functionality by means of differential short-term pre-anthesis canopy shading that modified the sink:source balance. We quantified the effects of these modifications on stay-green properties through a combination of gold standard physiological measurements of leaf activity and newly developed methods for organ-level senescence monitoring based on timeseries of high-resolution imagery and deep-learning-based semantic image segmentation. In parallel, we monitored CT by means of a pole-mounted thermal camera that delivered continuous, ultra-high temporal resolution CT data. Our results show that differences in stay-green functionality translate into measurable differences in CT in the absence of major confounding factors. Differences amounted to approximately 0.8°C and 1.5°C for a very high-yielding source-limited genotype, and a medium-yielding sink-limited genotype, respectively. The gradual nature of the effects of shading on CT during the stay-green phase underscore the importance of a high measurement frequency and a time-integrated analysis of CT, whilst modest effect sizes confirm the importance of restricting screenings to a limited range of morphological and phenological diversity.
PubMed: 38895615
DOI: 10.3389/fpls.2024.1335037 -
Sensors (Basel, Switzerland) Jun 2024Environmental mapping and robot navigation are the basis for realizing robot automation in modern agricultural production. This study proposes a new autonomous mapping...
Environmental mapping and robot navigation are the basis for realizing robot automation in modern agricultural production. This study proposes a new autonomous mapping and navigation method for gardening scene robots. First, a new LiDAR slam-based semantic mapping algorithm is proposed to enable the robots to analyze structural information from point cloud images and generate roadmaps from them. Secondly, a general robot navigation framework is proposed to enable the robot to generate the shortest global path according to the road map, and consider the local terrain information to find the optimal local path to achieve safe and efficient trajectory tracking; this method is equipped in apple orchards. The LiDAR was evaluated on a differential drive robotic platform. Experimental results show that this method can effectively process orchard environmental information. Compared with vnf and pointnet++, the semantic information extraction efficiency and time are greatly improved. The map feature extraction time can be reduced to 0.1681 s, and its MIoU is 0.812. The resulting global path planning achieved a 100% success rate, with an average run time of 4ms. At the same time, the local path planning algorithm can effectively generate safe and smooth trajectories to execute the global path, with an average running time of 36 ms.
PubMed: 38894456
DOI: 10.3390/s24113663 -
Journal of Clinical Medicine May 2024: The subject of this article is the reflection on hope-one of the most important predictors and motivators of human actions. Hope is our response to a threat, and it is...
: The subject of this article is the reflection on hope-one of the most important predictors and motivators of human actions. Hope is our response to a threat, and it is also the emotion that allows us to overcome hopelessness and to reduce suffering. Hoping is a human capacity with varying cognitive, emotional, and functional dimensions. Psychological, pedagogical (particularly in the framework of special-needs pedagogy and thanatological pedagogy), and theological reflection on hope can be helpful for dying people. The objective of this study was to characterize hope in the semantic space of individuals in the terminal stage of cancer and to verify whether age is a variable that determines this hope. : To complete the study, the Osgood semantic differential method was applied, as modified by Polish psychologist Dr. Boguslaw Block (the DSN-3 test). The research technique consisted of a therapeutic conversation. : Research results show that, in general, those in the terminal stage have positive associations with hope. In all three aspects of the used test, namely the cognitive, emotional, and functional aspects, the highest scores assigned to the perception of hope were obtained from men up to 35 years of age. Depending on the ages of patients, one could observe certain semantic shifts, but they did not prove to be statistically significant. : Polish males surveyed at the end of life due to cancer generally perceived hope as a supportive force. Therefore, hope can provide emotional support to patients in the terminal stage of cancer and improve their quality of life.
PubMed: 38892872
DOI: 10.3390/jcm13113162 -
Ecology and Evolution Jun 2024During past glacial periods, the land cover of Northern Eurasia and North America repeatedly shifted between open steppe tundra and boreal/temperate forest. Tracking...
During past glacial periods, the land cover of Northern Eurasia and North America repeatedly shifted between open steppe tundra and boreal/temperate forest. Tracking these changes and estimating the coverage of open versus forested vegetation in past glacial and interglacial landscapes is notoriously difficult because the characteristic dwarf birches of the tundra and the tree birches of the boreal and temperate forests produce similar pollen grains that are difficult to distinguish in the pollen record. One objective approach to separating dwarf birch pollen from tree birch pollen is to use grain size statistics. However, the required grain size measurements are time-consuming and, therefore, rarely produced. Here, we present an approach to automatic size measurement based on image recognition with convolutional neural networks and machine learning. It includes three main steps. First, the TOFSI algorithm is applied to detect and classify pollen, including birch pollen, in lake sediment samples. Second, a Resnet-18 neural network is applied to select the birch pollen suitable for measurement. Third, semantic segmentation is applied to detect the outline and the area and mean width of each detected birch pollen grain. Test applications with two pollen records from Northern Germany, one covering the Lateglacial-Early Holocene transition and the other covering the Mid to Late Pleistocene transition, show that the new technical approach is well suited to measure the area and mean width of birch pollen rapidly (>1000 per hour) and with high accuracy. Our new network-based tool facilitates more regular size measurements of birch pollen. Expanded analysis of modern birch pollen will help to better understand size variations in birch pollen between birch species and in response to environmental factors as well as differential sample preparation. Analysis of fossil samples will allow better quantification of dwarf birch versus tree birch in past environments.
PubMed: 38882530
DOI: 10.1002/ece3.11510 -
BMC Psychology May 2024People with neurodegenerative diseases may have difficulty learning new information, owing to their cognitive impairments. Teaching them techniques for learning in...
BACKGROUND
People with neurodegenerative diseases may have difficulty learning new information, owing to their cognitive impairments. Teaching them techniques for learning in social contexts could alleviate this difficulty. The present study will examine the performances of patients with Alzheimer's disease and patients with the semantic variant of primary progressive aphasia on a memory test administered in three social contexts. The protocol will make it possible to identify determinants of social interactions, social abilities, cognition, and personality that can explain the potentially beneficial effect of social context on learning in these patients.
METHODS
Thirty dyads (patient with primary memory impairment who meets criteria for Alzheimer's disease paired with caregiver), 16 dyads (patient meeting criteria for semantic variant of primary progressive aphasia paired with caregiver), and 46 dyads (healthy controls with no cognitive complaints) will be recruited. A nonverbal memory test (social memory task) will be administered to each dyad in three different social contexts (presence-only, observation, collaboration). Patients and healthy controls will also undergo a neuropsychological assessment to measure social (interactions and abilities), cognitive and personality aspects. Patients will be compared with controls on differential social scores calculated between the presence-only and collaboration contexts, and between the presence-only and observation contexts. A multiple comparative case study will be conducted to identify social, cognitive and personality variables that potentially explain the differential scores in the collaboration and observation contexts.
DISCUSSION
For the first time, memory will be assessed in patients with Alzheimer's disease and patients with the semantic variant of primary progressive aphasia in three different contexts (presence-only, observation, collaboration). The multiple comparative case study will make it possible to identify the determinants of memory performance in the social context, in order to create the most beneficial learning context for individual patients, according to their profile.
TRIAL REGISTRATION
This study was approved by the Ile de France XI institutional review board (2022-A00198-35), and registered on ClinicalTrials.gov (no. NCT05800028), on April 27, 2023.
Topics: Aged; Female; Humans; Male; Middle Aged; Alzheimer Disease; Aphasia, Primary Progressive; Cognition; Neurodegenerative Diseases; Neuropsychological Tests; Social Interaction; Social Learning
PubMed: 38807183
DOI: 10.1186/s40359-024-01791-w -
Technology and Health Care : Official... 2024Early diagnosis of knee osteoarthritis is an important area of research in the field of clinical medicine. Due to the complexity in the MRI imaging sequences and the...
BACKGROUND
Early diagnosis of knee osteoarthritis is an important area of research in the field of clinical medicine. Due to the complexity in the MRI imaging sequences and the diverse structure of cartilage, there are many challenges in the segmentation of knee bone and cartilage. Relevant studies have conducted semantic fusion processing through splicing or summing forms, which results in reduced resolution and the accumulation of redundant information.
OBJECTIVE
This study was envisaged to construct an MRI image segmentation model to improve the diagnostic efficiency and accuracy of different grade knee osteoarthritis by adopting the Dual Attention and Multi-scale Feature Fusion Segmentation network (DA-MFFSnet).
METHODS
The feature information of different scales was fused through the Multi-scale Attention Downsample module to extract more accurate feature information, and the Global Attention Upsample module weighted lower-level feature information to reduce the loss of key information.
RESULTS
The collected MRI knee images were screened and labeled, and the study results showed that the segmentation effect of DA-MFFSNet model was closer to that of the manually labeled images. The mean intersection over union, the dice similarity coefficient and the volumetric overlap error was 92.74%, 91.08% and 7.44%, respectively, and the accuracy of the differential diagnosis of knee osteoarthritis was 84.42%.
CONCLUSIONS
The model exhibited better stability and classification effect. Our results indicated that the Dual Attention and Multi-scale Feature Fusion Segmentation model can improve the segmentation effect of MRI knee images in mild and medium knee osteoarthritis, thereby offering an important clinical value and improving the accuracy of the clinical diagnosis.
Topics: Humans; Magnetic Resonance Imaging; Osteoarthritis, Knee; Knee Joint; Image Processing, Computer-Assisted; Algorithms; Image Interpretation, Computer-Assisted
PubMed: 38759056
DOI: 10.3233/THC-248024 -
PloS One 2024Using validated stimulus material is crucial for ensuring research comparability and replicability. However, many databases rely solely on bidimensional valence ratings,...
Using validated stimulus material is crucial for ensuring research comparability and replicability. However, many databases rely solely on bidimensional valence ratings, ranging from negative to positive. While this material might be appropriate for certain studies, it does not reflect the complexity of attitudes and therefore might hamper the unambiguous interpretation of some study results. In fact, most databases cannot differentiate between neutral (i.e., neither positive nor negative) and ambivalent (i.e., simultaneously positive and negative) attitudes. Consequently, even presumably univalent (only positive or negative) stimuli cannot be clearly distinguished from ambivalent ones when selected via bipolar rating scales. In the present research, we introduce the Trier Univalence Neutrality Ambivalence (TUNA) database, a database containing 304,262 validation ratings from heterogeneous samples of 3,232 participants and at least 20 (M = 27.3, SD = 4.84) ratings per self-report scale per picture for a variety of attitude objects on split semantic differential scales. As these scales measure positive and negative evaluations independently, the TUNA database allows to distinguish univalence, neutrality, and ambivalence (i.e., potential ambivalence). TUNA also goes beyond previous databases by validating the stimulus materials on affective outcomes such as experiences of conflict (i.e., felt ambivalence), arousal, anger, disgust, and empathy. The TUNA database consists of 796 pictures and is compatible with other popular databases. It sets a focus on food pictures in various forms (e.g., raw vs. cooked, non-processed vs. highly processed), but includes pictures of other objects that are typically used in research to study univalent (e.g., flowers) and ambivalent (e.g., money, cars) attitudes for comparison. Furthermore, to facilitate the stimulus selection the TUNA database has an accompanying desktop app that allows easy stimulus selection via a multitude of filter options.
Topics: Humans; Databases, Factual; Female; Male; Attitude; Adult; Young Adult; Adolescent; Middle Aged; Emotions
PubMed: 38753714
DOI: 10.1371/journal.pone.0302904 -
Cerebral Cortex (New York, N.Y. : 1991) May 2024While fronto-posterior underconnectivity has often been reported in autism, it was shown that different contexts may modulate between-group differences in functional...
While fronto-posterior underconnectivity has often been reported in autism, it was shown that different contexts may modulate between-group differences in functional connectivity. Here, we assessed how different task paradigms modulate functional connectivity differences in a young autistic sample relative to typically developing children. Twenty-three autistic and 23 typically developing children aged 6 to 15 years underwent functional magnetic resonance imaging (fMRI) scanning while completing a reasoning task with visuospatial versus semantic content. We observed distinct connectivity patterns in autistic versus typical children as a function of task type (visuospatial vs. semantic) and problem complexity (visual matching vs. reasoning), despite similar performance. For semantic reasoning problems, there was no significant between-group differences in connectivity. However, during visuospatial reasoning problems, we observed occipital-occipital, occipital-temporal, and occipital-frontal over-connectivity in autistic children relative to typical children. Also, increasing the complexity of visuospatial problems resulted in increased functional connectivity between occipital, posterior (temporal), and anterior (frontal) brain regions in autistic participants, more so than in typical children. Our results add to several studies now demonstrating that the connectivity alterations in autistic relative to neurotypical individuals are much more complex than previously thought and depend on both task type and task complexity and their respective underlying cognitive processes.
Topics: Humans; Child; Male; Adolescent; Female; Magnetic Resonance Imaging; Semantics; Autistic Disorder; Brain; Brain Mapping; Space Perception; Neural Pathways
PubMed: 38696600
DOI: 10.1093/cercor/bhae093 -
Frontiers in Neuroscience 2024Alzheimer's disease (AD) and Lewy body disease (LBD), the two most common causes of neurodegenerative dementia with similar clinical manifestations, both show impaired...
BACKGROUND
Alzheimer's disease (AD) and Lewy body disease (LBD), the two most common causes of neurodegenerative dementia with similar clinical manifestations, both show impaired visual attention and altered eye movements. However, prior studies have used structured tasks or restricted stimuli, limiting the insights into how eye movements alter and differ between AD and LBD in daily life.
OBJECTIVE
We aimed to comprehensively characterize eye movements of AD and LBD patients on naturalistic complex scenes with broad categories of objects, which would provide a context closer to real-world free viewing, and to identify disease-specific patterns of altered eye movements.
METHODS
We collected spontaneous viewing behaviors to 200 naturalistic complex scenes from patients with AD or LBD at the prodromal or dementia stage, as well as matched control participants. We then investigated eye movement patterns using a computational visual attention model with high-level image features of object properties and semantic information.
RESULTS
Compared with matched controls, we identified two disease-specific altered patterns of eye movements: diminished visual exploration, which differentially correlates with cognitive impairment in AD and with motor impairment in LBD; and reduced gaze allocation to objects, attributed to a weaker attention bias toward high-level image features in AD and attributed to a greater image-center bias in LBD.
CONCLUSION
Our findings may help differentiate AD and LBD patients and comprehend their real-world visual behaviors to mitigate the widespread impact of impaired visual attention on daily activities.
PubMed: 38646608
DOI: 10.3389/fnins.2024.1333894