Faster recognition of graspable targets defined by orientation in a visual search task.

Action video games foster competitive environments that demand rapid spatial navigation and decision-making. Action video gamers often exhibit faster response times and slightly improved accuracy in vision-based sensorimotor tasks. Background/Objectives: However, the underlying functional and structural changes in the two visual streams of the brain that may be contributing to these cognitive improvements have been unclear. Methods: Using functional and diffusion MRI data, this study investigated the differences in connectivity between gamers who play action video games and nongamers in the dorsal and ventral visual streams. Results: We found that action video gamers have enhanced functional and structural connectivity, especially in the dorsal visual stream. Specifically, there is heightened functional connectivity—both undirected and directed—between the left superior occipital gyrus and the left superior parietal lobule during a moving-dot discrimination decision-making task. This increased connectivity correlates with response time in gamers. The structural connectivity in the dorsal stream, as quantified by diffusion fractional anisotropy and quantitative anisotropy measures of the axonal fiber pathways, was also enhanced for gamers compared to nongamers. Conclusions: These findings provide valuable insights into how action video gaming can induce targeted improvements in structural and functional connectivity between specific brain regions in the visual processing pathways. These connectivity changes in the dorsal visual stream underpin the superior performance of action video gamers compared to nongamers in tasks requiring rapid and accurate vision-based decision-making.

As we move through our environment, we encounter familiar objects from various viewpoints. Despite the ensuing variability of the images projected onto the retina, we have seemingly little difficulty when it comes to recognizing objects we encounter. We can, however, see how the objects are oriented, suggesting that object recognition is to a certain degree dissociable from perception of other object “features” such as orientation. Changes in orientation of objects, particularly inversion, can also affect how we perceive the objects. A particularly illustrative example (shown in Figure ​Figure1)1) is that of the Thatcher illusion (Thompson, 1980), where the grotesque appearance of a face with its inverted eyes and mouth is “hidden” when the whole face is also inverted. The percept itself, therefore, is affected by the change in orientation. In addition, there are also subtle effects of viewpoint changes on object recognition itself. For example, identifying rotated objects is more difficult when they are briefly presented than when viewing time is unlimited (Lawson and Jolicoeur, 2003), and identifying a face is considerably more difficult the face has been inverted (Yin, 1969), as is discrimination between characters “b” and “d,” or “p” and “q” which requires (physical or mental) rotation of the characters to upright, before we can be certain which letter we are looking at (Corballis and McLaren, 1984). Figure 1 Unaltered and “thatcherized” version of Margaret Thatcher's face. The grotesque appearance of the face when its eyes and mouth are inverted is hidden by the inversion of the whole image. Rotating the pictures to upright makes discrimination ... These subtle, yet persistent, effects of viewpoint changes on perception and recognition arise as a consequence of how visual object processing is handled by the brain. Here, I discuss how neural mechanisms underlying visual processing give rise to perception and recognition which can be both viewpoint dependent and viewpoint invariant depending on the timing of those processes, as well as specific task demands or current “perceptual goals” of an individual. To do so, I will firstly explain how temporal dynamics of low-level visual processing may give rise to impaired recognition at short viewing latencies and suggest that this may also relate to effects of viewpoint changes on perceptual experience. I will then discuss how the perceptual goals of an individual determines whether recognition is accomplished in viewpoint invariant or dependent manner with a particular focus on cognitive operations thought to be subserved by ventral and dorsal visual streams, namely object recognition and mental rotation, respectively.

Prior research has demonstrated that scene cues within real-world environments significantly expedite visual search tasks, particularly when co-occurrence objects—those that tend to appear concurrently and in close proximity—are present. The underlying mechanisms driving these enhancements remain a subject of ongoing debate. In this study, we recruited forty-five participants to perform a visual search task using real-world scene images, with conditions involving either the presence or absence of co-occurrence objects, while recording their right eye movements. Our findings revealed that the presence of co-occurrence objects exclusively enhanced search accuracy, without impacting response times or fixation durations. As participants engaged in repeated searches, their performance improved, characterized by increased accuracy, reduced response times, fewer fixations, and shorter fixation durations, applicable to both target objects and co-occurrence objects alike. Notably, the effect of co-occurrence objects remained consistent across search iterations, indicating no change with accumulated search experience. Collectively, these outcomes suggest a strategic role for co-occurrence objects in guiding visual search processes, potentially mediated through the spatial processing of target objects. This study contributes to our understanding of how contextual cues influence visual attention and search precision in complex environments.

Differences in visual search tasks between congenitally deaf and normally hearing adults

Here, we ask which neural regions have neural response patterns that correlate with behavioral performance in a visual processing task. We found that the representational structure across all of high-level visual cortex has the requisite structure to predict behavior. Furthermore, when directly comparing different neural regions, we found that they all had highly similar category-level representational structures. These results point to a ubiquitous and uniform representational structure in high-level visual cortex underlying visual object processing.

Aging effects on functional auditory and visual processing using fMRI with variable sensory loading

The degree of interaction between the ventral and dorsal visual streams has been discussed in multiple scientific domains for decades. Recently, several white matter tracts that directly connect cortical regions associated with the dorsal and ventral streams have become possible to study due to advancements in automated and reproducible methods. The developmental trajectory of this set of tracts, here referred to as the posterior vertical pathway (PVP), has yet to be described. We propose an input-driven model of white matter development and provide evidence for the model by focusing on the development of the PVP. We used reproducible, cloud-computing methods and diffusion imaging from adults and children (ages 5-8years) to compare PVP development to that of tracts within the ventral and dorsal pathways. PVP microstructure was more adult-like than dorsal stream microstructure, but less adult-like than ventral stream microstructure. Additionally, PVP microstructure was more similar to the microstructure of the ventral than the dorsal stream and was predicted by performance on a perceptual task in children. Overall, results suggest a potential role for the PVP in the development of the dorsal visual stream that may be related to its ability to facilitate interactions between ventral and dorsal streams during learning. Our results are consistent with the proposed model, suggesting that the microstructural development of major white matter pathways is related, at least in part, to the propagation of sensory information within the visual system.

Heterogeneity of visual deficits in posterior cortical atrophy

Recently, many computational models have been proposed to simulate visual cognition process. For example, the hierarchical Max-Pooling (HMAX) model was proposed according to the hierarchical and bottom-up structure of V1 to V4 in the ventral pathway of primate visual cortex, which could achieve position- and scale-tolerant recognition. In our previous work, we have introduced memory and association into the HMAX model to simulate visual cognition process. In this paper, we improve our theoretical framework by mimicking a more elaborate structure and function of the primate visual cortex. We will mainly focus on the new formation of memory and association in visual processing under different circumstances as well as preliminary cognition and active adjustment in the inferior temporal cortex, which are absent in the HMAX model. The main contributions of this paper are: 1) in the memory and association part, we apply deep convolutional neural networks to extract various episodic features of the objects since people use different features for object recognition. Moreover, to achieve a fast and robust recognition in the retrieval and association process, different types of features are stored in separated clusters and the feature binding of the same object is stimulated in a loop discharge manner and 2) in the preliminary cognition and active adjustment part, we introduce preliminary cognition to classify different types of objects since distinct neural circuits in a human brain are used for identification of various types of objects. Furthermore, active cognition adjustment of occlusion and orientation is implemented to the model to mimic the top-down effect in human cognition process. Finally, our model is evaluated on two face databases CAS-PEAL-R1 and AR. The results demonstrate that our model exhibits its efficiency on visual recognition process with much lower memory storage requirement and a better performance compared with the traditional purely computational methods.

We used ERPs to investigate whether temporal attention interacts with spatial attention and feature-based attention to enhance visual processing. We presented a visual search display containing one singleton stimulus among a set of homogenous distractors. Participants were asked to respond only to target singletons of a particular color and shape that were presented in an attended spatial position. We manipulated temporal attention by presenting a warning signal before each search display and varying the foreperiod (FP) between the warning signal and the search display in a blocked manner. We observed distinctive ERP effects of both spatial and temporal attention. The amplitudes for the N2pc, SPCN, and P3 were enhanced by spatial attention indicating a processing benefit of relevant stimulus features at the attended side. Temporal attention accelerated stimulus processing; this was indexed by an earlier onset of the N2pc component and a reduction in reaction times to targets. Most importantly, temporal attention did not interact with spatial attention or stimulus features to influence visual processing. Taken together, the results suggest that temporal attention fosters visual perceptual processing in a visual search task independently from spatial attention and feature-based attention; this provides support for the nonspecific enhancement hypothesis of temporal attention.

Recent behavioral and neuroimaging studies using continuous flash suppression (CFS) have suggested that action-related processing in the dorsal visual stream might be independent of perceptual awareness, in line with the "vision-for-perception" versus "vision-for-action" distinction of the influential dual-stream theory. It remains controversial if evidence suggesting exclusive dorsal stream processing of tool stimuli under CFS can be explained by their elongated shape alone or by action-relevant category representations in dorsal visual cortex. To approach this question, we investigated category- and shape-selective functional magnetic resonance imaging-blood-oxygen level-dependent responses in both visual streams using images of faces and tools. Multivariate pattern analysis showed enhanced decoding of elongated relative to non-elongated tools, both in the ventral and dorsal visual stream. The second aim of our study was to investigate whether the depth of interocular suppression might differentially affect processing in dorsal and ventral areas. However, parametric modulation of suppression depth by varying the CFS mask contrast did not yield any evidence for differential modulation of category-selective activity. Together, our data provide evidence for shape-selective processing under CFS in both dorsal and ventral stream areas and, therefore, do not support the notion that dorsal "vision-for-action" processing is exclusively preserved under interocular suppression.

Visual search and visual lobe size: can training on one affect the other?

Do deaf people develop capacities of their remaining senses that exceed those of hearing individuals? Are the compensatory effects due to attention-dependent strategies? We investigated these questions, using texture segmentation and visual search tasks. The advantage of these tasks is that they contain attention-dependent and attention-independent components. We investigated 8 hearing adult observers, and 99 hearing and 89 deaf subjects aged between 6 and 20 years. The subject's task was to search for a discrepant stimulus among a number of distracting items. We used four different visual search tasks (circles with and without a 90° gap; circles with and without an added vertical line; pairs of convergent and parallel lines; tilted and vertical single lines) and oriented textures containing either a single line or a group of 16 discrepant lines. Visual search and texture segmentation tasks were randomly intermingled. Each subject participated in eight experimental runs, on two consecutive days. Both groups of subjects showed consistent learning effects for all tasks. In both groups, reaction times for all tasks decreased with age and reached an optimum at about 16 – 18 years. However, statistical comparisons do not indicate compensatory effects for deafness: reaction times and error rates of the deaf subjects were higher than those of the age-matched hearing subjects, for both the serial and the parallel tasks. These results were independent of the age and gender of the subjects and occurred for all etiologies for deafness. These results suggest deficiencies in the visual processing capacity of deaf subjects in tasks with and without attentional load.

THINGS-data reflects three large-scale neuroimaging and behavioral datasets of object processing in humans, comprising densely sampled functional MRI and magnetoencephalographic recordings, as well as 4.70 million similarity judgments in response to thousands of photographic images for up to 1854 objects.

In humans, motion information is mainly processed by the dorsal visual stream. This stream consists of two functional streams: the ventro-dorsal (v-d) and dorso-dorsal (d-d) streams. Patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) exhibit an impairment in motion perception. By using visual event-related potentials (ERPs), we have previously demonstrated that v-d function related to optic flow (OF) perception is selectively impaired in the dorsal stream in MCI patients. The present study is aimed at examining the difference in the changes in two functional dorsal streams among MCI and AD patients and healthy controls. Therefore, we recorded ERPs in response to OF and horizontal (HO) motion stimuli in patients with AD and MCI, and healthy controls. In all groups, motion-related N170 (V5/middle temporal (MT) origin) and OF-specific P200 (v-d origin) were elicited as major components. MCI patients showed a prolonged latency of P200 for OF but not of N170 for both stimuli compared with healthy controls. In contrast, the latencies of N170 for both stimuli and P200 for OF were significantly prolonged in AD patients compared with other groups. These findings indicate that MCI patients exhibit a selective impairment in the v-d stream, whereas AD patients have impairments in distributed dorsal stream function. These ERP results may reflect the progression of pathological changes in the course of the disease. Therefore, motion-related ERPs are useful to detect and track changes in the brain function of patients with MCI and AD.