Brain activities in the auditory area and insula represent stimuli evoking emotional response.

Cinema, a modern titan of entertainment, holds power to move people with the artful manipulation of auditory and visual stimuli. Despite this, the mechanisms behind how sensory stimuli elicit emotional responses are unknown. Thus, this study evaluated which brain regions were involved when sensory stimuli evoke auditory- or visual-driven emotions during film viewing. Using functional magnetic resonance imaging (fMRI) decoding techniques, we found that brain activities in the auditory area and insula represent the stimuli that evoke emotional response. The observation of brain activities in these regions could provide further insights to these mechanisms for the improvement of film-making, as well as the development of novel neural techniques in neuroscience. In near feature, such a "neuro-designed" products/ applications might gain in popularity.

Olfactory Stimulation Modulates Visual Perception Without Training.

Considerable research shows that olfactory stimulations affect other modalities in high-level cognitive functions such as emotion. However, little known fact is that olfaction modulates low-level perception of other sensory modalities. Although some studies showed that olfaction had influenced on the other low-level perception, all of them required specific experiences like perceptual training. To test the possibility that olfaction modulates low-level perception without training, we conducted a series of psychophysical and neuroimaging experiments. From the results of a visual task in which participants reported the speed of moving dots, we found that participants perceived the slower motions with a lemon smell and the faster motions with a vanilla smell, without any specific training. In functional magnetic resonance imaging (fMRI) studies, brain activities in the visual cortices [V1 and human middle temporal area (hMT)] changed based on the type of olfactory stimulation. Our findings provide us with the first direct evidence that olfaction modulates low-level visual perception without training, thereby indicating that olfactory-visual effect is not an acquired behavior but an innate behavior. The present results show us with a new crossmodal effect between olfaction and vision, and bring a unique opportunity to reconsider some fundamental roles of olfactory function.

Effect of illumination on perceived temperature.

The widely known hue-heat effect, a multisensory phenomenon between vision and thermal sensing, is a hypothesis based on the idea that light and colors affect perceived temperature. However, the application of this effect has not been prevalent in our daily lives. To work towards developing more practical use of the hue-heat effect, we conducted a series of psychophysical experiments to investigate the relationship between perceived temperature and illumination in a well-controlled experimental environment. The results showed that illumination had three types of effects to change our sense of coolness/warmness: creating, eliminating, and exchanging effects. Furthermore, we confirmed the existence of two distinctive time courses for the three effects: creating effect started immediately, but the eliminating effect takes time. These findings provide us with a better understanding of the hue-heat effect and enable us to apply it in everyday life. Paired with the new technologies it can also help with energy conservation.

Task-dependent fMRI decoder with the power to extend Gabor patch results to Natural images.

Scientists are often asked to what extent a simple finding in a laboratory can be generalized to complicated phenomena in our daily lives. The same is equally true of vision science; numerous critical discoveries about our visual system have been made using very simple visual images, such as Gabor patches, but to what extent can these findings be applied to more natural images? Here, we used the fMRI decoding technique and directly tested whether the findings obtained with primitive visual stimuli (Gabor patches) were applicable to natural images. In the fMRI experiments, participants performed depth and resolution tasks with both Gabor patches and natural images. We created a fMRI decoder made from the results of the Gabor patch experiments that classified a brain activity pattern into the depth or resolution task, and then examined how successful the task-dependent decoder could sort a brain activity pattern in the natural image experiment into the depth or resolution task. As a result, we found that the task-dependent decoder constructed from Gabor patch experiments could predict which task (depth or resolution task) a participant was engaged in the natural image experiments, especially in the V3 and middle temporal (MT+) areas of the brain. This is consistent with previous researches on the cortical activation relating to depth perception rather than perceptual processing of display resolution. These results provide firm evidence that fMRI decoding technique possesses the power to evaluate the application of Gabor patch results (laboratory findings) to the natural images (everyday affairs), representing a new approach for studying the mechanism of visual perception.

Not explicit but implicit memory is influenced by individual perception style.

Not only explicit but also implicit memory has considerable influence on our daily life. However, it is still unclear whether explicit and implicit memories are sensitive to individual differences. Here, we investigated how individual perception style (global or local) correlates with implicit and explicit memory. As a result, we found that not explicit but implicit memory was affected by the perception style: local perception style people more greatly used implicit memory than global perception style people. These results help us to make the new effective application adapting to individual perception style and understand some clinical symptoms such as autistic spectrum disorder. Furthermore, this finding might give us new insight of memory involving consciousness and unconsciousness as well as relationship between implicit/explicit memory and individual perception style.

Novel pegylated interferon-ß as strong suppressor of the malignant ascites in a peritoneal metastasis model of human cancer.

Malignant ascites manifests as an end-stage event during the progression of a number of cancers and lacks a generally accepted standard therapy. Interferon-ß (IFN-ß) has been used to treat several cancer indications; however, little is known about the efficacy of IFN-ß on malignant ascites. In the present study, we report on the development of a novel, engineered form of human and murine IFN-ß, each conjugated with a polyethylene glycol molecule (PEG-hIFN-ß and PEG-mIFN-ß, respectively). We provide evidence that these IFN-ß molecules retain anti-viral potency comparable to unmodified IFN-ß in vitro and manifested improved pharmacokinetics in vivo. Interestingly, PEG-mIFN-ß significantly inhibited the accumulation of ascites fluid and vascular permeability of the peritoneal membrane in models of ovarian cancer and gastric cancer cell xenograft mice. We further show that PEG-hIFN-ß directly suppresses VEGF165 -induced hyperpermeability in a monolayer of human vascular endothelial cells and that PEG-mIFN-ß enhanced gene expression for a number of cell adhesion related molecules in mouse vascular endothelial cells. Taken together, these findings unveil a hitherto unrecognized potential of IFN-ß in maintaining vascular integrity, and provide proof-of-mechanism for a novel and long-acting pegylated hIFN-ß for the therapeutic treatment of malignant ascites.

Undetectable Changes in Image Resolution of Luminance-Contrast Gradients Affect Depth Perception.

A great number of studies have suggested a variety of ways to get depth information from two dimensional images such as binocular disparity, shape-from-shading, size gradient/foreshortening, aerial perspective, and so on. Are there any other new factors affecting depth perception? A recent psychophysical study has investigated the correlation between image resolution and depth sensation of Cylinder images (A rectangle contains gradual luminance-contrast changes.). It was reported that higher resolution images facilitate depth perception. However, it is still not clear whether or not the finding generalizes to other kinds of visual stimuli, because there are more appropriate visual stimuli for exploration of depth perception of luminance-contrast changes, such as Gabor patch. Here, we further examined the relationship between image resolution and depth perception by conducting a series of psychophysical experiments with not only Cylinders but also Gabor patches having smoother luminance-contrast gradients. As a result, higher resolution images produced stronger depth sensation with both images. This finding suggests that image resolution affects depth perception of simple luminance-contrast differences (Gabor patch) as well as shape-from-shading (Cylinder). In addition, this phenomenon was found even when the resolution difference was undetectable. This indicates the existence of consciously available and unavailable information in our visual system. These findings further support the view that image resolution is a cue for depth perception that was previously ignored. It partially explains the unparalleled viewing experience of novel high resolution displays.

Higher resolution stimulus facilitates depth perception: MT+ plays a significant role in monocular depth perception.

Today, we human beings are facing with high-quality virtual world of a completely new nature. For example, we have a digital display consisting of a high enough resolution that we cannot distinguish from the real world. However, little is known how such high-quality representation contributes to the sense of realness, especially to depth perception. What is the neural mechanism of processing such fine but virtual representation? Here, we psychophysically and physiologically examined the relationship between stimulus resolution and depth perception, with using luminance-contrast (shading) as a monocular depth cue. As a result, we found that a higher resolution stimulus facilitates depth perception even when the stimulus resolution difference is undetectable. This finding is against the traditional cognitive hierarchy of visual information processing that visual input is processed continuously in a bottom-up cascade of cortical regions that analyze increasingly complex information such as depth information. In addition, functional magnetic resonance imaging (fMRI) results reveal that the human middle temporal (MT+) plays a significant role in monocular depth perception. These results might provide us with not only the new insight of our neural mechanism of depth perception but also the future progress of our neural system accompanied by state-of- the-art technologies.

Weaker signals induce more precise temporal-integration.

It is well known that our perceptual system integrates local information to generate global percepts. Although events in the real world occur over time, it is still unclear how we integrate temporally dispersed information. Here, I systematically explore the relation between the intensity of local signals and the resultant of temporal-integration. Presented sequentially with two directions of variably coherent random dot patterns (40 degrees apart), participants were instructed to report a perceived motion direction by using a mouse driven cursor. As the strength of the motion signal was varied, the behavioral results and qualitative analyses indicate existence of two aspects of temporal-integration, subthreshold integration and suprathreshold integration. In subthreshold integration (when the local signals are subthreshold), stronger signals enhance integration. On the other hand, in suprathreshold integration (when the signals are above threshold), stronger signals decrease integration. As a result, relatively weaker, subthreshold or near threshold signals produce more precise temporal-integration than suprathreshold signals.

Unattended exposure to components of speech sounds yields same benefits as explicit auditory training.

Learning a second language as an adult is particularly effortful when new phonetic representations must be formed. Therefore the processes that allow learning of speech sounds are of great theoretical and practical interest. Here we examined whether perception of single formant transitions, that is, sound components critical in speech perception, can be enhanced through an implicit task-irrelevant learning procedure that has been shown to produce visual perceptual learning. The single-formant sounds were paired at subthreshold levels with the attended targets in an auditory identification task. Results showed that task-irrelevant learning occurred for the unattended stimuli. Surprisingly, the magnitude of this learning effect was similar to that following explicit training on auditory formant transition detection using discriminable stimuli in an adaptive procedure, whereas explicit training on the subthreshold stimuli produced no learning. These results suggest that in adults learning of speech parts can occur at least partially through implicit mechanisms.

Roles of attention in perceptual learning from perspectives of psychophysics and animal learning.

The role of attention in perceptual learning has been a topic of controversy. Sensory psychophysicists/physiologists and animal learning psychologists have conducted numerous studies to examine this role; but because these two types of researchers use two very different lines of approach, their findings have never been effectively integrated. In the present article, we review studies from both lines and use exposure-based learning experiments to discuss the role of attention in perceptual learning. In addition, we propose a model in which exposure-based learning occurs only when a task-irrelevant feature is weak. We hope that this article will provide new insight into the role of attention in perceptual learning to the benefit of both sensory psychophysicists/physiologists and animal learning psychologists.

Task-irrelevant learning occurs only when the irrelevant feature is weak.

The role of attention in perceptual learning has been controversial. Numerous studies have reported that learning does not occur on stimulus features that are irrelevant to a subject's task [1,2] and have concluded that focused attention on a feature is necessary for a feature to be learned. In contrast, another line of studies has shown that perceptual learning occurs even on task-irrelevant features that are subthreshold, and concluded that attention on a feature is not required to learn that feature [3-5]. Here we attempt to reconcile these divergent findings by systematically exploring the relation between signal strength of the motion stimuli used during training and the resultant magnitude of perceptual learning. Our results show that performance improvements only occurred for the motion-stimuli trained at low, parathreshold, coherence levels. The results are in accord with the hypothesis that weak task-irrelevant signals fail to be 'noticed', and consequently to be suppressed, by the attention system and thus are learned, while stronger stimulus signals are detected, and suppressed [6], and are not learned. These results provide a parsimonious explanation of why task-irrelevant learning is found in some studies but not others, and could give an important clue to resolving a long-standing controversy.

Greater disruption due to failure of inhibitory control on an ambiguous distractor.

Considerable evidence indicates that a stimulus that is subthreshold, and thus consciously invisible, influences brain activity and behavioral performance. However, it is not clear how subthreshold stimuli are processed in the brain. We found that a task-irrelevant subthreshold coherent motion led to a stronger disturbance in task performance than did suprathreshold motion. With the subthreshold motion, activity in the visual cortex measured by functional magnetic resonance imaging was higher, but activity in the lateral prefrontal cortex was lower, than with suprathreshold motion. These results suggest that subthreshold irrelevant signals are not subject to effective inhibitory control.

Two cases requiring external reinforcement in perceptual learning.

The role of external reinforcement is an issue of much debate and uncertainty in perceptual learning research. Although it is commonly acknowledged that external reinforcement, such as performance feedback, can aid in perceptual learning (M. H. Herzog & M. Fahle, 1997), there are many examples in which it is not required (K. Ball & R. Sekuler, 1987; M. Fahle, S. Edelman, & T. Poggio, 1995; A. Karni & D. Sagi, 1991; S. P. McKee & G. Westheimer, 1978; L. P. Shiu & H. Pashler, 1992). Additionally, learning without external reinforcement can occur even for stimuli that are irrelevant to the subject's task (A. R. Seitz & T. Watanabe, 2003). It has been thus hypothesized that internal reinforcement can serve a similar role as external reinforcement in learning (M. H. Herzog & M. Fahle, 1998; A. Seitz & T. Watanabe, 2005). This idea suggests that perceptual learning should occur in the absence of external reinforcement provided that easy exemplars are utilized as a basis for the subject to generate internal reinforcement. Here, we report results from two studies that show that this is not always the case. In the first study, subjects participated in two sessions of a motion direction discrimination task with low-contrast dots moving in directions separated by 90 degrees. In the second study, subjects participated in 12 orientation-discrimination sessions using oriented bars (oriented either 70 degrees or 110 degrees) that were masked by spatial noise. Trials of different signal levels (yielding psychometric functions ranging from chance to ceiling) were randomly interleaved. In both studies, subjects experiencing external reinforcement showed significant learning, whereas subjects receiving no external reinforcement failed to show learning. We conclude that while internal reinforcement is an important learning signal, the presence of easy exemplars is not sufficient to generate reinforcement signals.