Storage Of Visual Information Research Articles

Evaluation of Brain Electrical Activity of Visual Working Memory with Time-Frequency Analysis.

The term visual working memory (VWM) refers to the temporary storage of visual information. In electrophysiological recordings during the change detection task which relates to VWM, contralateral negative slow activity was detected. It was found to occur during the information is kept in memory and it was called contralateral delay activity. In this study, the characteristics of electroencephalogram frequencies of the contralateral and ipsilateral responses in the retention phase of VWM were evaluated by using time-frequency analysis (discrete wavelet transform [DWT]) in the change detection task. Twenty-six volunteers participated in the study. Event-related brain potentials (ERPs) were examined, and then a time-frequency analysis was performed. A statistically significant difference between contralateral and ipsilateral responses was found in the ERP. DWT showed a statistically significant difference between contralateral and ipsilateral responses in the delta and theta frequency bands range. When volunteers were grouped as either high or low VWM capacity the time-frequency analysis between these groups revealed that high memory capacity groups have a significantly higher negative coefficient in alpha and beta frequency bands. This study showed that during the retention phase delta and theta bands may relate to visual memory retention and alpha and beta bands may reflect individual memory capacity.

Working memory: what does research say about oscillation and functional connectivity?

Working memory is a crucial cognitive function for processing and storing information in short-term memory during purposeful activities [1]. Numerous studies using EEG, MEG, and stereo-EEG were conducted to identify the neurophysiological correlates of working memory, including oscillations in specific brain regions in the absence of a memorized stimulus. The studies explored multiple aspects such as encoding, maintenance, processing, ordering, updating, and inhibition and various working memory modalities. Additionally, the studies highlighted the significance of examining the functional connectivity between different brain regions. As a result, researchers have amassed a large amount of data that is often contradictory and lacks organization [2]. The aim of this study is to perform a methodical review of literature published from 1980 up to the present period, cataloged in the Scopus, Web of Science, and Pubmed databases. The systematic review follows the PICo structure and addresses three main questions: which neuronal networks are involved in different working memory modalities and detect synchronizations between and within frequencies in cognitively safe subjects; are there disparities in the characteristics of neuronal networks between adults and the elderly; and can various interventions be employed to align the characteristics of neuronal networks in the elderly with those of adults [3]. The systematic review follows PRISMA-P 2015 protocol [4]. Main inclusion criteria focus on investigating working memory, analyzing visual, verbal and nonspecific modalities, using EEG/MEG/stereo-EEG, assessing adult and elderly subjects, and providing quantitative results from behavioral and neurocognitive research. Exclusion criteria: The study excluded emotional stimuli and assessments of long-term memory as well as the use of fMRI. Additionally, unigender studies and studies with subjects who had cognitive or other impairments were not included. In addition, the study required a sufficient number of subjects and time-frequency analysis. Moreover, physical or dietary interventions were excluded, and experimental research was necessary for inclusion. The study did not assess working memory in a foreign language for the subjects. A systematic review was conducted on the platform nested-knowledge.com. Based on the given criteria, a literature search was performed, yielding 2,828 articles meeting the inclusion criteria. These were further screened by two experts, resulting in the identification of 234 relevant articles, and upon full text review, 89 articles were deemed relevant. The resulting pool of articles is characterized by the following parameters: 69 articles describe adult subjects, 5 articles describe elderly subjects, and 12 articles compare both groups. Additionally, 42 articles focus on oscillation, 15 on functional connectivity, and 32 on both metrics. Concerning working memory, 22 articles describe all stages, 8 focus on encoding, 11 on encoding and maintenance, 4 on maintenance and recall, 23 on maintenance, 9 on maintenance and processing, 7 on processing, 1 on recall, and 3 without separating stages. Furthermore, 28 articles pertain to verbal memory, 51 to visual memory, 8 articles contain comparisons of modalities, and 2 articles discuss modally non-specific tasks. Preliminary findings from the systematic review indicate distinct functions of various frequency bands for working memory. Specifically, theta rhythms (4–8 Hz) in the frontal lobe were predominantly associated with information maintenance, while demonstrating a propension for increased synchronization during information processing. The alpha rhythm (8–14 Hz) was associated with inhibiting irrelevant data and protecting the current content of working memory, aligning with the widely accepted paradigm [5]. The beta rhythm (14–28 Hz) was most frequently noted to occur when maintaining and recalling information, and its power was associated with memory accuracy indicators. The gamma rhythm (28 Hz and higher) was seen during the process of encoding and maintaining information, and exhibited greater power for more complex stimuli. The analysis of connectivity revealed that encoding visual and verbal stimuli involves interhemispheric frontal-temporal and frontal-central connections that interact through theta rhythms. Additionally, storing information relies on the interplay of theta and gamma rhythms between the frontal and parietal networks. Notably, when dealing with verbal stimuli, the connectivity of the frontal and temporal brain lobes through theta rhythm enhances with load during storage. The alpha rhythm facilitates communication across posterior and frontal divisions during information storage, whereas beta rhythm is associated with frontal-temporal connections. During visual information storage, theta rhythm mediates communication across frontal-postcentral connections. As storage load increases, theta rhythm leads to strengthening of frontal-parietal and frontal-frontal connections until the threshold of working memory capacity is reached, after which these connections weaken. When processing information, connectivity of the right frontal-occipital network, right prefrontal and left occipital regions, right frontal and occipital-parietal areas for visual memory, and frontal-parietal regions for verbal memory were observed in the theta band. Connectivity of the occipital brain regions primarily occurred in the alpha spectrum, and temporal regions exhibited high frequencies. No specific differences were observed between the elderly and adults, aside from the suppression of low frequencies and the prevalence of high frequencies in the connectivity analysis.

Pattern of EEG voltage and oscillations under stimulation of Mozart’s music and white noise for visual learning process

The focus on behavioural data as a prominent indicator for evaluating the effect of stimulation on human cognitive function neglects the understanding of the body’s physiological responses. Another remain limitation is the physiological features usually analyzed from learning encode databases. Hence, the current research objectively investigates the correlation of EEG voltage and oscillations pattern from visual learning encoding and recognition stages under stimulation of various circumstances based on EEG patterns with behavioural data. The acquired EEG signal from visual assessment under no-audio and audio circumstances was processed using the Daubhecies wavelet function. The most affected EEG channels were identified according to the peak mean voltage from each electrode channel. The statistical features of mean, standard deviation, peak amplitude, and relative power were obtained from brain rhythms. The evaluation showed that the most affected EEG channel was at the Fp2 electrode with a voltage of about 0.1 V. It was related to the state of subjects that were required to identify the symbol and position of provided assessment. Most EEG features gained the highest value for recognition than the encoding stage, especially the relative power showed a statistically significant value with a p-value < 0.05. This revealed that brain oscillations were higher during recognition than encoding because the brain needed to work hard to retrieve the stored visual information. The behavioural data were parallel and in line with EEG rhythms pattern, where the highest brain oscillation led to better visual score performance. Throughout the evaluation, it was found that the EEG voltage and rhythms pattern during encoding were correlated with recognition and behavioural data.

Flexible utilization of spatial- and motor-based codes for the storage of visuo-spatial information.

Working memory provides flexible storage of information in service of upcoming behavioral goals. Some models propose specific fixed loci and mechanisms for the storage of visual information in working memory, such as sustained spiking in parietal and prefrontal cortex during working memory maintenance. An alternative view is that information can be remembered in a flexible format that best suits current behavioral goals. For example, remembered visual information might be stored in sensory areas for easier comparison to future sensory inputs, or might be re-coded into a more abstract action-oriented format and stored in motor areas. Here, we tested this hypothesis using a visuo-spatial working memory task where the required behavioral response was either known or unknown during the memory delay period. Using functional magnetic resonance imaging (fMRI) and multivariate decoding, we found that there was less information about remembered spatial position in early visual and parietal regions when the required response was known versus unknown. Furthermore, a representation of the planned motor action emerged in primary somatosensory, primary motor, and premotor cortex during the same task condition where spatial information was reduced in early visual cortex. These results suggest that the neural networks supporting working memory can be strategically reconfigured depending on specific behavioral requirements during a canonical visual working memory paradigm.

Cognitive neuroscience: Mental replay in monkeys

Cognition allows sensory experiences to inform later actions in flexible ways. A new study shows that, in a cognitively demanding task, monkeys store visual information in short-term memory and replay it when they need it to make a decision.

The visual arrays task: Visual storage capacity or attention control?

Extant literature suggests that performance on visual arrays tasks reflects limited-capacity storage of visual information. However, there is also evidence to suggest that visual arrays task performance reflects individual differences in controlled processing. The purpose of this study is to empirically evaluate the degree to which visual arrays tasks are more closely related to memory storage capacity or measures of attention control. To this end, we conducted new analyses on a series of large data sets that incorporate various versions of a visual arrays task. Based on these analyses, we suggest that the degree to which the visual arrays is related to memory storage ability or effortful attention control may be task-dependent. Specifically, when versions of the task require participants to ignore elements of the target display, individual differences in controlled attention reliably provide unique predictive value. Therefore, at least some versions of the visual arrays tasks can be used as valid indicators of individual differences in attention control. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Affective Modulation of Working Memory Maintenance: The Role of Positive and Negative Emotions.

The present study investigated the impact of task-irrelevant emotional images on the retention of information in spatial working memory (WM). Two experiments employed a delayed matching to-sample task where participants had to maintain the locations of four briefly presented squares. After a short retention interval, a probe item appeared and participants were required to indicate whether the probe position matched one of the previously occupied square positions. During the retention interval, task-irrelevant negative, positive, or neutral emotional pictures were presented. The results revealed a dissociation between negative and positive affect on the participants' ability to hold spatial locations in WM. While negative affective pictures reduced WM capacity, positive pictures increased WM capacity relative to the neutral images. Moreover, the specific valence and arousal of a given emotional picture was also related to WM performance: While higher valence enhanced WM capacity, higher levels of arousal in turn reduced WM capacity. Together, our findings suggest that emotions up- or down-regulate attention to items in WM and thus modulate the short term storage of visual information in memory.

Categorical distinctiveness constrains the labeling benefit in visual working memory

• Visual working memory (VWM) has a limited capacity to store visual information. • Labels categorize the visual stimuli, increasing categorical representations in VWM. • Labeling also increases continuous information about the stimulus in VWM. • The increase in continuous information depends on the distinctiveness of the labels. • Labels that are used to categorize many stimuli, reduce memory precision. Describing our visual experiences improves their retention in visual working memory, yielding a labeling benefit. Labels vary, however, in categorical distinctiveness: they can be applied broadly or narrowly to categorize stimuli. Does categorical distinctiveness constrain the labeling benefit? Here, we varied the number of terms used to label continuously varying colors (Experiment 1) and shapes (Experiment 2). Participants memorized four items, and later recalled them using a continuous color or shape wheel. During study, participants articulated “bababa” or labeled the items with two, four, or their preferred term. Recall error decreased with increases in the number of labels. Mixture modeling showed that labeling increased the probability of recall. Memory precision, however, varied with categorical distinctiveness: broad labels reduced precision, whereas categorically distinct labels increased precision compared to no-labels. In sum, in-the-moment labeling activates categorical knowledge that facilitates the storage of visual details. Data and analysis scripts are available at: https://osf.io/mqg4k/

Stimulus-Specific Visual Working Memory Representations in Human Cerebellar Lobule VIIb/VIIIa.

fMRI research has revealed that cerebellar lobule VIIb/VIIIa exhibits load-dependent activity that increases with the number of items held in visual working memory (VWM). However, it remains unclear whether these cerebellar responses reflect processes specific to VWM or more general visual attentional mechanisms. To investigate this question, we examined whether cerebellar activity during the delay period of a VWM task is selective for stimuli held in working memory. A sample of male and female human subjects performed a VWM continuous report task in which they were retroactively cued to remember the direction of motion of moving dot stimuli. Cerebellar lobule VIIb/VIIIa delay-period activation accurately decoded the direction of the remembered stimulus, as did frontal and parietal regions of the dorsal attention network. Arguing against a motor explanation, no other cerebellar area exhibited stimulus specificity, including the oculomotor vermis, a key area associated with eye movement control. Finer-scale analysis revealed that the medial portion of lobule VIIb and to a lesser degree the lateral most portion of lobules VIIb and VIIIa, which exhibit robust resting state connectivity with frontal and parietal regions of the dorsal attention network, encoded the identity of the remembered stimulus, while intermediate portions of lobule VIIb/VIIIa did not. These findings of stimulus-specific coding of VWM within lobule VIIb/VIIIa indicate for the first time that the distributed network responsible for the encoding and maintenance of mnemonic representations extends to the cerebellum.SIGNIFICANCE STATEMENT There is considerable debate concerning where in the brain the contents of visual working memory (VWM) are stored. To date, this literature has primarily focused on the role of regions located within cerebral cortex. There is growing evidence for cerebellar involvement in higher-order cognitive functions including working memory. While the cerebellum has been previously shown to be recruited by VWM paradigms, it is unclear whether any portion of cerebellum actively encodes and maintains mnemonic representations. The present study demonstrates that cerebellar lobule VIIb/VIIIa activity patterns are selective for remembered stimuli and that this selectivity persists in the absence of perceptual input. These findings provide novel evidence for the participation of cerebellar structures in the persistent storage of visual information.

Functional dissociation of anterior cingulate cortex and intraparietal sulcus in visual working memory

Previous electrophysiological studies of lateralized visual working memory (VWM) identified an ERP component, defined as contralateral delay activity (CDA), directly modulated by the number of items held in memory. One of the main candidate as the cortical source of this ERP component is the inferior intraparietal sulcus (IPS). Moreover, previous neuroimaging studies put forth evidence for the presence of a distributed VWM network involving also prefrontal areas and in particular the anterior cingulate cortex (ACC). Nonetheless, the understanding of the functional role of ACC is still debated. We recorded the high-density EEG in 20 healthy participants undergoing a VWM and a control task. Explorative cluster-based permutation statistics confirmed the posterior memory load dependent CDA modulation, but also identified an additional anterior cluster of electrodes whose amplitude was modulated by memory load. The source reconstruction revealed a memory load dependent activation in the IPS but also in the ACC, suggesting that these two areas might be nodes of a fronto-parietal circuit underlying VWM maintenance. Crucially, parietal and prefrontal areas showed a temporal dissociation, since IPS was more engaged in the early phase of visual information storage while the ACC was more active during the late phase. This pattern suggests a functional dissociation between the parietal cortex, which is involved in encoding and storage of information, and prefrontal areas, subserving cognitive control processes, including the boosting and protection of information from decay. Remarkably, the connection strength between IPS and ACC predicted the individual number of items held in memory. These findings are discussed within the theoretical account of a neural distributed model of VWM.

Advancing Metal-Phenolic Networks for Visual Information Storage.

We report a facile inking strategy for visual information storage (e.g., writing, printing, and beyond) via surface modification of substrates with polyphenols and subsequent in situ formation of metal-phenolic networks (MPNs) on the substrates. The reported technique has several advantages compared with current printing techniques. Diverse substrates can be used to fulfill the requirements for different applications (e.g., printing, writing, painting, and stamping). A range of colors (e.g., yellow, blue, and green) can be realized using different polyphenols (e.g., tannic acid, gallic acid, and pyrogallol) and metal ions (e.g., CuII, FeIII, and TiIV). The disadvantages (e.g., ink precipitation, color fading) associated with writing or printing using traditional ink can be overcome. The obtained paintings can be easily removed by acids enabling the recycling of substrates. The reported strategy provides a new avenue for the development of portable, nontoxic, and green technologies for writing, printing, and beyond, which expands the applications of MPN-based materials.

Does visual working memory adapt to the nature of anticipated interference?

Visual working memory (VWM) is an important memory buffer to briefly store visual information for ongoing tasks. Evidence shows that VWM representations can be protected against interfering input during the maintenance period. In this study, we investigated whether the protection of VWM representations is selective with regards to the anticipated nature of the interference, or whether VWM automatically protects all information in the wake of interference. In two experiments, participants were required to memorize both the color and the orientation of grating pattern for a memory test at the end of a delay period. During the delay period, either an additional color or an additional orientation memory task was presented. Which type of interfering task (color or orientation) would be presented was predictable with 80% likelihood. The results showed that memory for orientation survived orientation interference better when orientation interference was expected than when color interference was expected. Likewise, memory for color survived color interference better when color interference was expected than when orientation interference was expected. We conclude that visual working memory protection is adaptive in that it selectively shields the feature for which it expects the strongest interference.

Visual long-term memory is not unitary: Flexible storage of visual information as features or objects as a function of affect.

Research has shown that observers store surprisingly highly detailed long-term memory representations of visual objects after only a single viewing. However, the nature of these representations is currently not well understood. In particular, it may be that the nature of such memory representations is not unitary but reflects the flexible operating of two separate memory subsystems: a feature-based subsystem that stores visual experiences in the form of independent features, and an object-based subsystem that stores visual experiences in the form of coherent objects. Such an assumption is usually difficult to test, because overt memory responses reflect the joint output of both systems. Therefore, to disentangle the two systems, we (1) manipulated the affective state of observers (negative vs. positive) during initial object perception, to introduce systematic variance in the way that visual experiences are stored, and (2) measured both the electrophysiological activity at encoding (via electroencephalography) and later feature memory performance for the objects. The results showed that the nature of stored memory representations varied qualitatively as a function of affective state. Negative affect promoted the independent storage of object features, driven by preattentive brain activities (feature-based memory representations), whereas positive affect promoted the dependent storage of object features, driven by attention-related brain activities (object-based memory representations). Taken together, these findings suggest that visual long-term memory is not a unitary phenomenon. Instead, incoming information can be stored flexibly by means of two qualitatively different long-term memory subsystems, based on the requirements of the current situation.

Psychologically inspired visual information storage and retrieval modeling for multiclass image classification

The computer vision research aims to enable the computers to recognize visual images as easily as human. Studies have shown that human could segregate target from its surrounding environment, which is intimately associated with the brain memory mechanism. However, it is not quite clear about how the visual images are stored and retrieved in the human brain. In this paper, we propose a psychologically visual information storage and retrieval model (PVISRM) based on sparse coding and probabilistic decision theory. First, the dense scale invariant feature transform (SIFT) algorithm is applied to extract the features of visual images and then the extracted features are represented by sparse coding. In the storage procedure, each component of the feature vector is correctly copied with certain probability generated by an exponential distribution. For retrieval, the likelihood ratio between the probe image feature vector and that of each studied image is calculated based on probabilistic theory. Then the category likelihood ratio between the probe image and each category is obtained by adding the ratio values of all images belonging to the same category. Finally, the Bayesian decision rule for image classification is presented. Experimental results show that the proposed PVISRM model can obtain good classification performance and outperforms the SVM approach.

DoD Visual Information Storage Challenges and Lessons Learned

DoD Visual Information Storage Challenges and Lessons Learned

Otoliths as individual indicators: a reappraisal of the link between fish physiology and otolith characteristics

Otoliths are remarkable recorders that store visual and chemical information that can be interpreted with regard to individual fish phenotype trajectory, life history events and environment. However, the information stored in the otoliths must be interpreted with the knowledge that the otolith is an integral part of fish sensory systems. This means that the environmental signals recorded in the otoliths will be regulated by the homeostatic apparatus of the individual fish – its physiology and ultimately its genetic make-up. Although this may complicate interpretation of environmental signals, it also opens up avenues for new research into the physiology and life history of individual fish. This review focuses on research areas where the coupling between otolith characteristics and fish physiology may yield new insights. Most of the research ideas are by no means new, but rather represent largely forgotten or less-explored research areas. Examples of questions that are fundamental, unanswered and with the potential to yield significant new insights are those related to the coupling of otolith and fish growth through metabolism, and the formation of opaque and translucent growth zones in relation to the physiology of the individual. An integration of visual and chemical data with bioenergetic modelling may yield some of the answers.

The working memory Ponzo illusion: Involuntary integration of visuospatial information stored in visual working memory

Visual working memory (VWM) has been traditionally viewed as a mental structure subsequent to visual perception that stores the final output of perceptual processing. However, VWM has recently been emphasized as a critical component of online perception, providing storage for the intermediate perceptual representations produced during visual processing. This interactive view holds the core assumption that VWM is not the terminus of perceptual processing; the stored visual information rather continues to undergo perceptual processing if necessary. The current study tests this assumption, demonstrating an example of involuntary integration of the VWM content, by creating the Ponzo illusion in VWM: when the Ponzo illusion figure was divided into its individual components and sequentially encoded into VWM (so that the four lines in Ponzo figure components were never simultaneously presented), the temporally separated components were involuntarily integrated, leading to the distorted length perception of the two horizontal lines. This VWM Ponzo illusion was replicated when the figure components were presented in different combinations and presentation order. The magnitude of the illusion was significantly correlated between VWM and perceptual versions of the Ponzo illusion. These results suggest that the information integration underling the VWM Ponzo illusion is constrained by the laws of visual perception and similarly affected by the common individual factors that govern its perception. Thus, our findings provide compelling evidence that VWM functions as a buffer serving perceptual processes at early stages. Meeting abstract presented at VSS 2015

The working memory Ponzo illusion: Involuntary integration of visuospatial information stored in visual working memory

Visual working memory (VWM) has been traditionally viewed as a mental structure subsequent to visual perception that stores the final output of perceptual processing. However, VWM has recently been emphasized as a critical component of online perception, providing storage for the intermediate perceptual representations produced during visual processing. This interactive view holds the core assumption that VWM is not the terminus of perceptual processing; the stored visual information rather continues to undergo perceptual processing if necessary. The current study tests this assumption, demonstrating an example of involuntary integration of the VWM content, by creating the Ponzo illusion in VWM: when the Ponzo illusion figure was divided into its individual components and sequentially encoded into VWM, the temporally separated components were involuntarily integrated, leading to the distorted length perception of the two horizontal lines. This VWM Ponzo illusion was replicated when the figure components were presented in different combinations and presentation order. The magnitude of the illusion was significantly correlated between VWM and perceptual versions of the Ponzo illusion. These results suggest that the information integration underling the VWM Ponzo illusion is constrained by the laws of visual perception and similarly affected by the common individual factors that govern its perception. Thus, our findings provide compelling evidence that VWM functions as a buffer serving perceptual processes at early stages.

Reward associations impact both iconic and visual working memory

Reward plays a fundamental role in human behavior. A growing number of studies have shown that stimuli associated with reward become salient and attract attention. The aim of the present study was to extend these results into the investigation of iconic memory and visual working memory. In two experiments we asked participants to perform a visual-search task where different colors of the target stimuli were paired with high or low reward. We then tested whether the pre-established feature-reward association affected performance on a subsequent visual memory task, in which no reward was provided. In this test phase participants viewed arrays of 8 objects, one of which had unique color that could match the color associated with reward during the previous visual-search task. A probe appeared at varying intervals after stimulus offset to identify the to-be-reported item. Our results suggest that reward biases the encoding of visual information such that items characterized by a reward-associated feature interfere with mnemonic representations of other items in the test display. These results extend current knowledge regarding the influence of reward on early cognitive processes, suggesting that feature-reward associations automatically interact with the encoding and storage of visual information, both in iconic memory and visual working memory.

Independent effects of resolution and set size on recognition memory for unfamilar faces

Visual working memory (VWM) is a limited-capacity resource for the temporary storage of visual information (Cowan, 2001). Selective visual attention can protect VWM capacity by filtering relevant from irrelevant information during encoding or maintenance (Griffin & Nobre, 2003). The current study was designed to investigate the consequences of attentional selection on the accuracy of recognition for unfamiliar faces. We used a Change Detection task to measure d’ for cued and uncued faces in displays of 1, 2 and 4 faces, in a free-view (Experiment 1) and single-fixation Experiment 2) displays. In both experiments, recall accuracy was greater for cued than uncued faces. Recognition accuracy was also higher in free-view compared to single fixation displays and declined as a function of set size. This suggests the acquisition of high spatial frequency information during saccadic sampling improves recognition memory. Importantly, this advantage appears to be independent of the decrease in accuracy associated with set size, indicating that increasing the resolution of memoranda in VWM does not dilute resources in the same way as increasing the number of objects to remember.