Encoding Of Pictures Research Articles

Dynamic causal modeling of reorganization of memory and language networks in temporal lobe epilepsy.

To evaluate the alterations of language and memory functions using dynamic causal modeling, in order to identify the epileptogenic hemisphere in temporal lobe epilepsy (TLE). Twenty-two patients with left TLE and 13 patients with right TLE underwent functional magnetic resonance imaging (fMRI) during four memory and four language mapping tasks. Dynamic causal modeling (DCM) was employed on fMRI data to examine effective directional connectivity in memory and language networks and the alterations in people with TLE compared to healthy individuals. DCM analysis suggested that TLE can influence the memory network more widely compared to the language network. For memory mapping, it demonstrated overall hyperconnectivity from the left hemisphere to the other cranial regions in the picture encoding, and from the right hemisphere to the other cranial regions in the word encoding tasks. On the contrary, overall hypoconnectivity was seen from the brain hemisphere contralateral to the seizure onset in the retrieval tasks. DCM analysis further manifested hypoconnectivity between the brain's hemispheres in the language network in patients with TLE compared to controls. The CANTAB® neuropsychological test revealed a negative correlation for the left TLE and a positive correlation for the right TLE cohorts for the connections extracted by DCM that were significantly different between the left and right TLE cohorts. In this study, dynamic causal modeling evidenced the reorganization of language and memory networks in TLE that can be used for a better understanding of the effects of TLE on the brain's cognitive functions.

Human cerebellum and corticocerebellar connections involved in emotional memory enhancement

Emotional information is better remembered than neutral information. Extensive evidence indicates that the amygdala and its interactions with other cerebral regions play an important role in the memory-enhancing effect of emotional arousal. While the cerebellum has been found to be involved in fear conditioning, its role in emotional enhancement of episodic memory is less clear. To address this issue, we used a whole-brain functional MRI approach in 1,418 healthy participants. First, we identified clusters significantly activated during enhanced memory encoding of negative and positive emotional pictures. In addition to the well-known emotional memory-related cerebral regions, we identified a cluster in the cerebellum. We then used dynamic causal modeling and identified several cerebellar connections with increased connection strength corresponding to enhanced emotional memory, including one to a cluster covering the amygdala and hippocampus, and bidirectional connections with a cluster covering the anterior cingulate cortex. The present findings indicate that the cerebellum is an integral part of a network involved in emotional enhancement of episodic memory.

Optimized GAN for Text-to-Image Synthesis: Hybrid Whale Optimization Algorithm and Dragonfly Algorithm

Text to image synthesizes is a motivating and valuable task to explore in these days. The objective is to produce images from texts or captions, i.e. considering textual descriptions as input and deploying them to produce related images. For carrying this task, two challenging elements of image generation and language modeling should be combined that are said to be more complex than caption generation. This research aims to develop a new text-to-image synthesis method that includes the two crucial steps of (i) text to picture encoding and (ii) optimized GAN. At first, cross-modal feature grouping is done throughout the text to image encoding. Consequently, text embeddings are transformed into textual feature vectors using BI-LSTM. The images are created based on the encoding in the following stage. Thus, optimized GAN receives input from text feature groups and outputs the end synthesis images. Here, a research plans to train the GAN with optimization strategy via tuning the optimal weights using the Dragon Customized Whale Optimization (DC-WO) model. Finally, the superiority of the created approach is evaluated by comparing it to existing techniques. Additionally, the FID value of the proposed model using the cub dataset is 29.04%, 47.43%, 49.09%, 37.64% and 11.35%, superior to traditional FF, WOA, GWO, DA and GAN + CMAF models.

Limbic Responses to Aversive Visual Stimuli during the Acute and Recovery Phase of Takotsubo Syndrome

The role of the limbic system in the acute phase and during the recovery of takotsubo syndrome needs further clarification. In this longitudinal study, anatomical and task-based functional magnetic resonance imaging of the brain was performed during an emotional picture paradigm in 19 postmenopausal female takotsubo syndrome patients in the acute and recovery phases in comparison to sex- and aged-matched 15 healthy controls and 15 patients presenting with myocardial infarction. Statistical analyses were performed based on the general linear model where aversive and positive picture conditions were included in order to reveal group differences during encoding of aversive versus positive pictures and longitudinal changes. In the acute phase, takotsubo syndrome patients showed a lower response in regions involved in affective and cognitive emotional processes (e.g., insula, thalamus, frontal cortex, inferior frontal gyrus) while viewing aversive versus positive pictures compared to healthy controls and patients presenting with myocardial infarction. In the recovery phase, the response in these brain regions normalized in takotsubo syndrome patients to the level of healthy controls, whereas patients 8–12 weeks after myocardial infarction showed lower responses in the limbic regions (mainly in the insula, frontal regions, thalamus, and inferior frontal gyrus) compared to healthy controls and takotsubo syndrome patients. In conclusion, compared to healthy controls and patients suffering from acute myocardial infarction, limbic responses to aversive visual stimuli are attenuated during the acute phase of takotsubo syndrome, recovering within three months. Reduced functional brain responses in the recovery phase after a myocardial infarction need further investigation.

Emotional modulation of episodic memory in children and adolescents with Williams-Beuren syndrome

ABSTRACT Children and adolescents with Williams-Beuren syndrome (WBS) have been described as having specific memory abilities and emotional reactivity. Although it is well established in the literature that emotion can enhance memory, no such studies have been undertaken in individuals with WBS. In three experiments, the present study tested whether the negative or positive emotional valence of stimuli can influence verbal, visual and visuo-spatial memory by specifically evaluating two memory components: item and associative memory. Sixteen 8- to 18-year-old individuals with WBS performed the first two experiments and, among them, twelve participated in the third. They were compared to equivalent groups of typically developing control children. Participants completed intentional-encoding tasks followed by immediate item recognition, associative recall or item recall tasks. Event-related potential measures during encoding and recognition of pictures were also added in the third experiment. Results demonstrated, for the first time, effects of emotions on visual item memory and visuo-spatial associative memory in individuals with WBS, that were similar to those observed in typically developing children. By combining behavioral and neural measures, our study provides new knowledge of the interaction between emotion and memory in WBS individuals, which seems to be unaffected by their atypical development.

Splitting sleep between the night and a daytime nap reduces homeostatic sleep pressure and enhances long-term memory

Daytime naps have been linked with enhanced memory encoding and consolidation. It remains unclear how a daily napping schedule impacts learning throughout the day, and whether these effects are the same for well-rested and sleep restricted individuals. We compared memory in 112 adolescents who underwent two simulated school weeks containing 8 or 6.5 h sleep opportunities each day. Sleep episodes were nocturnal or split between nocturnal sleep and a 90-min afternoon nap, creating four experimental groups: 8 h-continuous, 8 h-split, 6.5 h-continuous and 6.5 h-split. Declarative memory was assessed with picture encoding and an educationally realistic factual knowledge task. Splitting sleep significantly enhanced afternoon picture encoding and factual knowledge under both 6.5 h and 8 h durations. Splitting sleep also significantly reduced slow-wave energy during nocturnal sleep, suggesting lower homeostatic sleep pressure during the day. There was no negative impact of the split sleep schedule on morning performance, despite a reduction in nocturnal sleep. These findings suggest that naps could be incorporated into a daily sleep schedule that provides sufficient sleep and benefits learning.

Efficient Low Power Region Enhanced Architectures For DWT And AES For Protected Coding Image

In this article presents an HDL template on the ASIC platform. For quicker and safer image data transmission stable encoding of pictures via image compression and AES through encryption, the DWT was facilitated. The DWT calculation algorithm based on a lifting scheme and a multi-level sub-bands on the ASIC platform are created. 2D-DWTwas built using it. The related sub-bands were chosen to minimize the compression time of the AES encryption, based on compression ratio and data recovery. To ensure high efficiency and latency, the DWT architecture was developedHDL model and AES algorithm for the area, timing and power performance of the ASIC platform have been developed and validated for the DWT architecture. Using 56 nm CMOS technology, the ASIC implementation was carried out.

Memory performance following napping in habitual and non-habitual nappers

Study ObjectivesAfternoon naps benefit memory but this may depend on whether one is a habitual napper (HN; ≥1 nap/week) or non-habitual napper (NN). Here, we investigated whether a nap would benefit HN and NN differently, as well as whether HN would be more adversely affected by nap restriction compared to NN.MethodsForty-six participants in the nap condition (HN-nap: n = 25, NN-nap: n = 21) took a 90-min nap (14:00–15:30 pm) on experimental days while 46 participants in the Wake condition (HN-wake: n = 24, NN-wake: n = 22) remained awake in the afternoon. Memory tasks were administered after the nap to assess short-term topographical memory and long-term memory in the form of picture encoding and factual knowledge learning respectively.ResultsAn afternoon nap boosted picture encoding and factual knowledge learning irrespective of whether one habitually napped (main effects of condition (nap/wake): ps < 0.037). However, we found a significant interaction for the hippocampal-dependent topographical memory task (p = 0.039) wherein a nap, relative to wake, benefitted habitual nappers (HN-nap vs HN-wake: p = 0.003) compared to non-habitual nappers (NN-nap vs. NN-wake: p = 0.918). Notably for this task, habitual nappers’ performance significantly declined if they were not allowed to nap (HN-wake vs NN-wake: p = 0.037).ConclusionsContrary to concerns that napping may be disadvantageous for non-habitual nappers, we found that an afternoon nap was beneficial for long-term memory tasks even if one did not habitually nap. Naps were especially beneficial for habitual nappers performing a short-term topographical memory task, as it restored the decline that would otherwise have been incurred without a nap.Clinical Trial InformationNCT04044885.

Feedback timing modulates interactions between feedback processing and memory encoding: Evidence from event-related potentials.

Feedback-based learning relies on a procedural learning system driven by reward prediction errors (RPEs). The processing of temporally delayed feedback is supported by brain structures associated with declarative memory processes, but it is still unknown how delayed feedback processing and memory encoding interact. In this study, a subsequent memory paradigm was employed to investigate how the incidental encoding of feedback pictures presented with a short (SD, 500 ms) or long (LD, 6500 ms) delay in a probabilistic learning task affects the event-related potential (ERP) correlate of RPEs (i.e., the feedback-related negativity; FRN). In an ensuing test phase, a surprise recognition memory test for the feedback pictures was conducted. FRN amplitudes measured in the feedback-locked ERPs recorded during the learning phase (FRNpeak) and in the negative minus positive feedback difference wave (FRNdiff) were compared for subsequently remembered and forgotten feedback pictures. Feedback processing as reflected in the FRNpeak was diminished for remembered LD feedback pictures, indicating that delayed feedback processing and memory encoding competed for similar neural processing resources. As evidenced by large FRNdiff amplitudes in the SD condition, the evaluation of shortly delayed feedback strongly relied on the procedural learning system. A complementary model-based single trial analysis was conducted to validate models of the functional significance of the FRN. Consistent with previous studies, feedback-locked N170 and P300 amplitudes were sensitive to feedback delay. In the test phase, memory for LD feedback pictures was better than for SD pictures and accompanied by a late old-new effect, presumably reflecting extended recollective processing.

Bayesian Methods for Radiometric Calibration in Motion Picture Encoding Workflows

The accurate estimation of a camera response function (CRF) allows for proper encoding of camera exposures into motion picture post-production workflows like the Academy Color Encoding System (ACES), helping minimize noncreative manual adjustments. Although there are well-known standard CRFs implemented in typical video camera workflows, motion picture camera workflows and new high dynamic range (HDR) workflows have introduced new standard CRFs, as well as custom and proprietary CRFs. Current methods to estimate this function rely on the use of test charts, restrictive exposure and/or lighting conditions, or assume a simplistic model of the function’s shape. All of these methods become problematic and tough to fit into motion picture production and post-production workflows, where the use of test charts and varying camera or scene setups becomes impractical. We propose a method initially based on the work of Lin, Gu, Yamazaki, and Shum that considers edge color mixtures in an image or image sequence that are affected by the nonlinearity introduced by a CRF. This feature is then used in a Bayesian framework to estimate a posterior probability distribution function of the CRF model parameters approximated by a Markov Chain Monte Carlo (MCMC) algorithm, allowing for a more robust description of the CRF over methods like maximum likelihood (ML) and maximum a posteriori (MAP).

Predicting emotional arousal and emotional memory performance from an identical brain network

Encoding and retrieval of emotionally arousing stimuli depend on the activation of multiple interconnected brain regions, with people showing differences in their individual strength of emotional perception and recollection. Understanding the association between these brain regions and the behavioral outcome might therefore have important clinical implications as dysfunctional emotional memory processes are characteristic of many psychiatric disorders. Based on behavioral and fMRI data collected from healthy young adults (N = 1’385), we investigated brain activation patterns, arousal ratings and memory performance during encoding and retrieval of negative and neutral pictures. We performed multi-voxel pattern analysis (MVPA) and voxel-wise association analyses. Subjects' individual strength of perceived arousal at encoding and subjects' memory performance at recognition could be predicted from the fMRI data of the respective tasks by using a topographically identical network of brain regions. This network was mainly left lateralized including dense clusters of voxels in the occipital and parietal lobe and including the amygdala. Voxel-wise association analyses confirmed the close link between the brain activation of both tasks and their relation to the respective behavioral outcome. These results point to the importance of the here identified brain network for emotional memory processes in health and, possibly, disease.

Picture quality assessment-based on rate control for variable bandwidth networks

The growing popularity of Internet applications and services has rendered high subjective video quality crucial to the user experience. Increasing needs for better video resolution and faster transmission bandwidths present challenges to the goal of achieving balance between video quality and coding cost. In this paper, we propose a Perceptive Variable Bit-Rate Control (PVBRC) framework for the state-of-the-art video coding standard High-Efficiency Video Coding (HEVC)/H.265. PVBRC allocates a bit-rate to a picture while taking a Comprehensive Picture Quality Assessment (CPQA) model and perceptive target bit-rate allocation into consideration. The CPQA model calculates the objective and perceptive quality of both source and reconstructed pictures by referring to the human vision system. The coding bit-rate is then dynamically allocated by the result of the CPQA model according to differences in picture content. In PVBRC, the quantization parameter for current picture encoding is updated by an effective fuzzy logical controller to satisfy the transmission requirements of the Internet of Things. Experimental results show that the proposed PVBRC can achieve average bit savings by 11.49% when compared with constant bit-rate control under the same objective and subjective video quality.

Rest-related consolidation protects the fine detail of new memories

Newly encoded memories are labile and consolidate over time. The importance of sleep in memory consolidation has been well known for almost a decade. However, recent research has shown that awake quiescence, too, can support consolidation: people remember more new memories if they quietly rest after encoding than if they engage in a task. It is not yet known how exactly this rest-related consolidation benefits new memories, and whether it affects the fine detail of new memories. Using a sensitive picture recognition task, we show that awake quiescence aids the fine detail of new memories. Young adults were significantly better at discriminating recently encoded target pictures from similar lure pictures when the initial encoding of target pictures had been followed immediately by 10 minutes of awake quiescence than an unrelated perceptual task. This novel finding indicates that, in addition to influencing how much we remember, our behavioural state during wakeful consolidation determines, at least in part, the level of fine detail of our new memories. Thus, our results suggest that rest-related consolidation protects the fine detail of new memories, allowing us to retain detailed memories.

Linear and inverted U-shaped dose-response functions describe estrogen effects on hippocampal activity in young women

In animals, 17-beta-estradiol (E2) enhances hippocampal plasticity in a dose-dependent, monotonically increasing manner, but this relationship can also exhibit an inverted U-shaped function. To investigate E2’s dose-response function in the human hippocampus, we pharmacologically increased E2 levels in 125 naturally cycling women (who were in their low-hormone menstruation phase) to physiological (equivalent to menstrual cycle peak) and supraphysiological (equivalent to levels during early pregnancy) concentrations in a placebo-controlled design. Twenty-four hours after first E2 intake, we measured brain activity during encoding of neutral and negative pictures and then tested recognition memory 24 h after encoding. Here we report that E2 exhibits both a monotonically increasing relationship with hippocampal activity as well as an inverted U-shaped relationship, depending on the hippocampal region. Hippocampal activity exhibiting a U-shaped relationship inflects at supraphysiological E2 levels, suggesting that while E2 within physiological ranges stimulates hippocampal activity, supraphysiological ranges show opposite effects.

Functional brain networks during picture encoding and recognition in different odor contexts

Contextual odors can serve as retrieval cues when applied during encoding and recall/recognition of information. To investigate the neuronal basis of these observations, we collected functional MRI data while participants (n=51) performed an encoding and recognition memory task during which odors (congruent: CO or incongruent: IO) were presented as contextual cues. Recognition performance was not influenced by odor, but there was increased activation in the piriform cortex during successful encoding in the CO group, possibly indicating enhanced retrieval of information previously integrated with an olfactory percept. Moreover, group-independent component analysis revealed a stronger task-modulation of subcortical networks for IO versus CO during the recognition task, pointing to differences in olfactory processing. These observations provide a deeper understanding of the involvement of functional neuronal networks in memory tasks and a basis for further evaluation of the impact of odor contexts.

1-2 適応ブロックサイズ特異値分解を用いた静止画像符号化に関する一考察

1-2 適応ブロックサイズ特異値分解を用いた静止画像符号化に関する一考察

General and emotion-specific neural effects of ketamine during emotional memory formation

Animal studies suggest that N-methyl-D-aspartate receptor (NMDAR) dependent signalling in limbic and prefrontal regions is critically involved in both cognitive and emotional functions. In humans, ketamine-induced transient, and disorder associated chronic NMDAR hypofunction (i.e. in schizophrenia) has been associated with deficient performance in the domains of memory and higher-order emotional functioning, as well as altered neural activity in the underlying limbic-prefrontal circuits. To model the effects of NMDAR hypofunction on the integration of emotion and cognition the present pharmacological fMRI study applied the NMDAR antagonist ketamine (target plasma level=100ng/ml) to 21 healthy volunteers in a within-subject placebo-controlled crossover design during encoding of neutral, positive and negative pictures. Our results show that irrespective of emotion, ketamine suppressed parahippocampal and medial prefrontal activity. In contrast, ketamine selectively increased amygdala and orbitofrontal activity during successful encoding of negative stimuli. On the network level ketamine generally increased medial prefrontal-parahippocampal coupling while specifically decreasing amygdala-orbitofrontal interplay during encoding of negative stimuli. On the behavioural level, ketamine produced generally decreased memory performance and abolished the emotional enhancement of memory after a wash-out period of 5 days. The present findings suggest that ketamine produces general as well as valence-specific effects during emotional memory formation. The pattern partly overlaps with alterations previously observed in patients with schizophrenia.

P223 Adaptability and reproducibility of a memory disruption rTMS protocol in the PharmaCog IMI European project

Introduction The capacity of repetitive TMS to transiently interfere with cognitive processes in humans may offer an experimental platform for pharmacological studies. Developing compounds could then be tested to reverse artificially generated cognitive dysfunction, providing first hints of efficacy. In the FP7-IMI European ’Pharmacog’ Project, an rTMS protocol previously published in the literature, was adapted and validated as a ’cognitive challenge model’ to mimic episodic memory dysfunction occurring in early Alzheimer’s disease. However, it would be desirable to test whether the effects of TMS are comparable and reproducible across different centres and time-point assessments. Objectives Our main aims were, (1) to find out if visual memory interference through rTMS administration could be replicated using our specific experimental settings and task adaptations (Fig. 1), (2) to test if results are comparable in two centres and (3) to investigate if the effects obtained are reproducible when subjects are re-tested 15 days later. Methods 68 healthy young male subjects were included. Neuronavigated (Fig. 1) repetitive TMS was applied over the left dorsolateral prefrontal cortex (LDLPFC) or the Vertex area (control condition) during encoding of pictures, for latter memory recognition. Subjects attended one of two research centres in three main occasions: On visit 1, rTMS was applied using a sham coil and served as a baseline measure. On visit 2, real rTMS was administered. On visit 3, 15 days later, a subsample (N = 21) performed the same protocol to test for reproducibility of effects. Results A time (visit 1 vs visit 2) × TMS type (LDLPFC vs Vertex) ANOVA and posterior pairwise comparisons revealed that only rTMS delivered over the LDLPFC and during visit 2 day resulted in a significant decrease in subsequent memory recognition (F = 8.95, p = 0.004; Fig. 2a). No centre effect observed (F = 0.03, p = 0.96). Initial rTMS effects could not be replicated in the subsample (Fig. 2b). Conclusions Our findings offers positive evidence regarding the feasibility of adapting a rTMS cognitive interference protocol, to conduct new experimental research in separate independent institutions. The factors underlying the lack of test–retest reproducibility of the interference should be further investigated. Download : Download high-res image (345KB) Download : Download full-size image Download : Download high-res image (400KB) Download : Download full-size image

Lateral and medial prefrontal contributions to emotion generation by semantic elaboration during episodic encoding.

Memories for emotion-laden stimuli are remembered more accurately than those for neutral stimuli. Although this enhancement reflects stimulus-driven modulation of memory by emotions, functional neuroimaging evidence of the interacting mechanisms between emotions generated by intentional processes, such as semantic elaboration, and memory is scarce. The present fMRI study investigated how encoding-related activation is modulated by emotions generated during the process of semantic elaboration. During encoding with fMRI, healthy young adults viewed neutral (target) pictures either passively or with semantic elaboration. In semantic elaboration, participants imagined background stories related to the pictures. Encoding trials with semantic elaboration were subdivided into conditions in which participants imagined negative, positive, or neutral stories. One week later, memories for target pictures were tested. In behavioral results, memories for target pictures were significantly enhanced by semantic elaboration, compared to passive viewing, and the memory enhancement was more remarkable when negative or positive stories were imagined. fMRI results demonstrated that activations in the left inferior frontal gyrus and dorsal medial prefrontal cortex (dmPFC) were greater during the encoding of target pictures with semantic elaboration than those with passive viewing, and that these activations further increased during encoding with semantic elaboration of emotional stories than of neutral stories. Functional connectivity between the left inferior frontal gyrus and dmPFC/hippocampus during encoding significantly predicted retrieval accuracies of memories encoded with self-generated emotional stories. These findings suggest that networks including the left inferior frontal region, dmPFC, and hippocampus could contribute to the modulation of memories encoded with the emotion generation.

A multimodal imaging study of recognition memory in very preterm born adults.

Very preterm (<32 weeks of gestation) birth is associated with structural brain alterations and memory impairments throughout childhood and adolescence. Here, we used functional MRI (fMRI) to study the neuroanatomy of recognition memory in 49 very preterm‐born adults and 50 controls (mean age: 30 years) during completion of a task involving visual encoding and recognition of abstract pictures. T1‐weighted and diffusion‐weighted images were also collected. Bilateral hippocampal volumes were calculated and tractography of the fornix and cingulum was performed and assessed in terms of volume and hindrance modulated orientational anisotropy (HMOA). Online recognition memory task performance, assessed with A scores, was poorer in the very preterm compared with the control group. Analysis of fMRI data focused on differences in neural activity between the recognition and encoding trials. Very preterm born adults showed decreased activation in the right middle frontal gyrus and posterior cingulate cortex/precuneus and increased activation in the left inferior frontal gyrus and bilateral lateral occipital cortex (LOC) compared with controls. Hippocampi, fornix and cingulum volume was significantly smaller and fornix HMOA was lower in very preterm adults. Among all the structural and functional brain metrics that showed statistically significant group differences, LOC activation was the best predictor of online task performance (P = 0.020). In terms of association between brain function and structure, LOC activation was predicted by fornix HMOA in the preterm group only (P = 0.020). These results suggest that neuroanatomical alterations in very preterm born individuals may be underlying their poorer recognition memory performance. Hum Brain Mapp 38:644–655, 2017. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.