The Visual World in Memory

Influence of a sensorimotor conflict on the memorization of a path traveled in virtual reality

Recent studies have challenged the ventral/"what" and dorsal/"where" two-visual-processing-pathway view by showing the existence of "what" and "where" information in both pathways. Is the two-pathway distinction still valid? Here, we examined how goal-directed visual information processing may differentially impact visual representations in these two pathways. Using fMRI and multivariate pattern analysis, in three experiments on human participants (57% females), by manipulating whether color or shape was task-relevant and how they were conjoined, we examined shape-based object category decoding in occipitotemporal and parietal regions. We found that object category representations in all the regions examined were influenced by whether or not object shape was task-relevant. This task effect, however, tended to decrease as task-relevant and irrelevant features were more integrated, reflecting the well-known object-based feature encoding. Interestingly, task relevance played a relatively minor role in driving the representational structures of early visual and ventral object regions. They were driven predominantly by variations in object shapes. In contrast, the effect of task was much greater in dorsal than ventral regions, with object category and task relevance both contributing significantly to the representational structures of the dorsal regions. These results showed that, whereas visual representations in the ventral pathway are more invariant and reflect "what an object is," those in the dorsal pathway are more adaptive and reflect "what we do with it." Thus, despite the existence of "what" and "where" information in both visual processing pathways, the two pathways may still differ fundamentally in their roles in visual information representation.SIGNIFICANCE STATEMENT Visual information is thought to be processed in two distinctive pathways: the ventral pathway that processes "what" an object is and the dorsal pathway that processes "where" it is located. This view has been challenged by recent studies revealing the existence of "what" and "where" information in both pathways. Here, we found that goal-directed visual information processing differentially modulates shape-based object category representations in the two pathways. Whereas ventral representations are more invariant to the demand of the task, reflecting what an object is, dorsal representations are more adaptive, reflecting what we do with the object. Thus, despite the existence of "what" and "where" information in both pathways, visual representations may still differ fundamentally in the two pathways.

The article shows the importance of solving various production problems using processing, analysis and display of visual information. The existing systems for processing visual information are considered and the insufficiently developed use of automated image processing systems in production systems that solve rather complex and “intelligent” problems of image analysis is noted. The prospects of using digital modeling of object images are shown. The article provides a literary review of works on the development of methods and models for effective processing of visual control information, which showed that there are many unresolved issues. This work is aimed at solving some of them. The relevance of the topic and the objectives of the research are determined. Based on the results of the studies performed, a model of the visual information processing system was developed. From the object under study, a video stream arrives at the input of the model of the visual information processing system, which is first selected as a sequence of frames (frames) of a fixed dimension. Then there is a preliminary processing of the information received from the object, its segmentation, extraction of features and decision making. Here, the traditional number of homogeneous segments can be applied, into which the object is divided using the principle of maximum posterior probability. The result obtained is then used in the adaptation block. The proposed model of the visual information processing system was implemented in the Qt Creator environment in C ++.

Visual working memory (VWM) is used to maintain visual information available for subsequent goal-directed behavior. The content of VWM has been shown to affect the behavioral response to concurrent visual input, suggesting that visual representations originating from VWM and from sensory input draw upon a shared neural substrate (i.e., a sensory recruitment stance on VWM storage). Here, we hypothesized that visual information maintained in VWM would enhance the neural response to concurrent visual input that matches the content of VWM. To test this hypothesis, we measured fMRI BOLD responses to task-irrelevant stimuli acquired from 15 human participants (three males) performing a concurrent delayed match-to-sample task. In this task, observers were sequentially presented with two shape stimuli and a retro-cue indicating which of the two shapes should be memorized for subsequent recognition. During the retention interval, a task-irrelevant shape (the probe) was briefly presented in the peripheral visual field, which could either match or mismatch the shape category of the memorized stimulus. We show that this probe stimulus elicited a stronger BOLD response, and allowed for increased shape-classification performance, when it matched rather than mismatched the concurrently memorized content, despite identical visual stimulation. Our results demonstrate that VWM enhances the neural response to concurrent visual input in a content-specific way. This finding is consistent with the view that neural populations involved in sensory processing are recruited for VWM storage, and it provides a common explanation for a plethora of behavioral studies in which VWM-matching visual input elicits a stronger behavioral and perceptual response.SIGNIFICANCE STATEMENT Humans heavily rely on visual information to interact with their environment and frequently must memorize such information for later use. Visual working memory allows for maintaining such visual information in the mind's eye after termination of its retinal input. It is hypothesized that information maintained in visual working memory relies on the same neural populations that process visual input. Accordingly, the content of visual working memory is known to affect our conscious perception of concurrent visual input. Here, we demonstrate for the first time that visual input elicits an enhanced neural response when it matches the content of visual working memory, both in terms of signal strength and information content.

Chapter 4 - The Contribution of Human Superior Intraparietal Sulcus to Visual Short-Term Memory and Perception

The aim of this research was to verify whether perceived distance anisotropy exists even when visual information are available, that is, to examine interaction of non-visual (vestibular and proprioceptive) and visual information in depth perception. An experiment was done in a forest, where there is a large number of equally distributed depth cues. Partiticipants were instructed to equalize the distance of the stimuli towards horizon with the distance of the standard towards zenith. As a stimuli we used paper circles, 30cm in diameter, and participants performed their task from standing and lying position. Results have shown that estimated distances towards horizon were longer than physically identical distances towards zenith, which means that distances towards horizon are being perceived as shorter. Shorten age of perceived distances towards horizon was smaller from lying position. These findings point out significance of vestibular and proprioceptive information on percieved distance anisotropy, regardless of presence of visual information.

A birth cohort observational study to assess the association of prenatal biomarkers of organophosphates with visual attention, recognition memory and information processing among Thai infants

PERFEX: An expert system for interpreting 3D myocardial perfusion

ABSTRACTGraphical password composition is an important part of graphical user authentication which affects the strength of the chosen password. Considering that graphical authentication is associated with visual search, perception, and information retrieval, in this paper we report on an eye-tracking study (N = 109) that aimed to investigate the effects of users’ cognitive styles toward the strength of the created passwords and shed light into whether and how the visual strategy of the users during graphical password composition is associated with the passwords’ strength. For doing so, we adopted Witkin’s Field Dependence-Independence theory, which underpins individual differences in visual information and cognitive processing, as graphical password composition tasks are associated with visual search. The analysis revealed that users with different cognitive processing characteristics followed different patterns of visual behavior during password composition which affected the strength of the created passwords. The findings underpin the need of considering human-cognitive characteristics as a design factor in graphical password schemes. The paper concludes by discussing implications for improving recognition-based graphical passwords through adaptation and personalization techniques based on individual cognitive characteristics.

Head direction (HD) neurons, signalling facing direction, generate a signal that is primarily anchored to the outside world by visual inputs. We investigated the route for visual landmark information into the HD system in rats. There are two candidates: an evolutionarily older, larger subcortical retino-tectal pathway and a more recently evolved, smaller cortical retino-geniculo-striate pathway. We disrupted the cortical pathway by lesioning the dorsal lateral geniculate thalamic nuclei bilaterally, and recorded HD cells in the postsubicular cortex as rats foraged in a visual-cue-controlled enclosure. In lesioned rats we found the expected number of postsubicular HD cells. Although directional tuning curves were broader across a trial, this was attributable to the increased instability of otherwise normal-width tuning curves. Tuning curves were also poorly responsive to polarizing visual landmarks and did not distinguish cues based on their visual pattern. Thus, the retino-geniculo-striate pathway is not crucial for the generation of an underlying, tightly tuned directional signal but does provide the main route for vision-based anchoring of the signal to the outside world, even when visual cues are high in contrast and low in detail. KEY POINTS: Head direction (HD) cells indicate the facing direction of the head, using visual landmarks to distinguish directions. In rats, we investigated whether this visual information is routed through the thalamus to the visual cortex or arrives via the superior colliculus, which is a phylogenetically older and (in rodents) larger pathway. We lesioned the thalamic dorsal lateral geniculate nucleus (dLGN) in rats and recorded the responsiveness of cortical HD cells to visual cues. We found that cortical HD cells had normal tuning curves, but these were slightly more unstable during a trial. Most notably, HD cells in dLGN-lesioned animals showed little ability to distinguish highly distinct cues and none to distinguish more similar cues. These results suggest that directional processing of visual landmarks in mammals requires the geniculo-cortical pathway, which raises questions about when and how visual directional landmark processing appeared during evolution.

학습자의 정보처리유형에 따른 e-Book 인터페이스의 설계 및 개발은 학습자 중심의 적성처지교수를 위해 중요한 이슈가 된다. 이에 본 연구에서는 하이퍼텍스트 정보구조가 제공된 e-Book 학습환경에서 학습자의 정보처리유형이 학습내용 이해 및 사용 편의성에 있어 어떠한 차이를 보이는지를 검증해 봄으로써 보다 처방적인 e-Book 인터페이스의 설계전략에 대한 시사점을 제공하고자 하였다. 본 연구를 위해 대학생 68명이 참여하였으며, 하이퍼텍스트 정보구조가 제공된 e-Book 콘텐츠를 통해 학습한 후 정보처리유형(시각 정보처리, 언어 정보처리)에 따른 학업성취도 (텍스트 구조 파악 및 학습내용이해)와 사용 편의성에 대한 효과성을 검증하였다. 연구결과, 학업성취도에 있어서는 정보처리 유형에 따라 텍스트 구조 파악에는 유의미한 차이가 나타났으나, 학습내용 이해에는 유의미한 차이가 나타나지 않았다. 사용 편의성에 있어서는 학습자의 정보처리유형에 따라 유의미한 차이가 나타났으며, 구체적으로는 텍스트 구조 파악의 용이성, 텍스트 분량 파악의 용이성, 네비게이션의 용이성, 그리고 내용기억의 편의성 등에 있어 유의미한 차이가 나타났다. 또한 학업성취도에 영향을 미친 사용 편의성의 주요요인은 학습위치 파악의 용이성이었으며, 정보처리유형의 집단간 분류의 정확도는 79.4%로 비교적 높은 것으로 나타났다. 이러한 결과를 바탕으로 e-Book 콘텐츠 설계 및 개발에 대한 전략적 시사점에 논의 되었다. The purpose of this study is to examine difference of information processing style on lesson comprehension scores and usability ratings in e-Learning containing visual information structure. To address this goal, 68 university students were participated in this research. They were asked information processing style test, lesson comprehension test, and usability ratings after completed e-Learning lesson. According to the result, there was not significant difference between visual and verbal information process style on lesson comprehension as learn outcomes. However, students who are visual information processing style were significantly higher ratings than students who are verbal information processing style on 4 of 8 usability scales; awareness of lesson structure, awareness of lesson length, ease of navigation, and ease of lesson learning. These result indicate that there will be needed the design of aptitude treatment interaction for e-Book according to information processing style.

ObjectiveWe aim to study the effect of persistent post-concussive symptoms on cognitive performance of elite athletes, based on the hypothesis that persistent symptoms could impair athletes’ cognitive performances and functional...

Despite increasing recognition of the significance of mild traumatic brain injury (mTBI), the long-term cognitive consequences of the injury remain unclear. More sensitive measures that can detect subtle cognitive changes and consideration of individual variability are needed to properly characterise cognitive outcomes following mTBI. Here, we used complex behavioural tasks, individual differences approaches, and electrophysiology to investigate the long-term cognitive effects of a history of mTBI. In Experiment 1, participants with self-reported mTBI history (n=82) showed poorer verbal working memory performance on the operation span task compared to control participants (n=88), but there were no group differences in visual working memory, multitasking, cognitive flexibility, attentional control, visuospatial ability, or information processing speed. Individual differences analyses revealed that time since injury and presence of memory loss predicted visual working memory capacity and visuospatial ability, respectively, in those with mTBI history. In Experiment 2, participants with mTBI history (n=20) again demonstrated poorer verbal working memory on the operation span task compared to control participants (n=38), but no group differences were revealed on a visuospatial complex span task or simpler visual working memory measures. We also explored the electrophysiological indices of visual working memory using EEG during a change detection task. No differences were observed in early sensory event-related potentials (P1, N1) or the later negative slow wave associated with visual working memory capacity. Together, these findings suggest that mTBI history may be associated with a lasting, isolated disruption in the subsystem underlying verbal working memory storage. The results emphasise the importance of sensitive cognitive measures and accounting for individual variability in injury characteristics when assessing mTBI outcomes.

Phase synchronization of oscillatory brain activity and the matching of top-down and bottom up visual information

Acute effects of lorazepam on visual information processing, perceptual priming and explicit memory are well established. However, visual processing and perceptual priming have rarely been explored in long-term lorazepam users. By exploring these functions it was possible to test the hypothesis that difficulty in processing visual information may lead to deficiencies in perceptual priming. Using a simple blind procedure, we tested explicit memory, perceptual priming and visual perception in 15 long-term lorazepam users and 15 control subjects individually matched according to sex, age and education level. Explicit memory, perceptual priming, and the identification of fragmented pictures were found to be preserved in long-term lorazepam users, contrary to what is usually observed after an acute drug intake. The processing of visual contour, on the other hand, was still significantly impaired. These results suggest that the effects observed on low-level visual perception are independent of the acute deleterious effects of lorazepam on perceptual priming. A comparison of perceptual priming in subjects with low- vs. high-level identification of new fragmented pictures further suggests that the ability to identify fragmented pictures has no influence on priming. Despite the fact that they were treated with relatively low doses and far from peak plasma concentration, it is noteworthy that in long-term users memory was preserved.