Three experiments used near-infrared spectroscopy (NIRS) to examine brain activation in the frontal cortex during comprehending and reporting the contents of a story. In Experiment 1, the participants were asked to view humorous comic strip stories under the following two conditions: comprehending and reporting the contents after the experiment (report condition), and not reporting the contents (non-report condition). The changes of Oxy-Hb concentration in the left prefrontal region were higher in the report condition than in the non-report condition. In Experiments 2A and 2B the participants were asked to arrange sets of cards, according to either story development or shape complexity, without reporting the content of the story. The changes of Oxy-Hb concentration in the left and right prefrontal regions were higher for card arrangements related to story development than for those related to shape complexity. When articulatory suppression was used, activation in part of the left prefrontal region was reduced. The anterior portion of the left inferior frontal gyrus (around BA47) was consistently activated when participants actively tried to understand content, regardless of the type of task and memory load. We suggest a new objective method, using NIRS, with which to measure the brain activity associated with trying to understand content.
In various neuroscientific studies the hippocampus is reported to play crucial roles in declarative memory. The hippocampus is composed of several synaptic field subdivisions, such as the dentate gyrus, CA3 and CA1. Synaptic plasticity in these areas is thought to be a candidate for the biological basis of memory function. In the last decade there have been efforts to elucidate the memory functions of each synaptic subfield by using gene-manipulated animals and recombinant viral vector-infected animals. The underlying circuit mechanisms have been studied by electrophysiological recordings from the hippocampus of the animals. High spatial resolution functional MRI must be used to clearly define the activated areas within the hippocampus of the living human brain, and studies using a high resolution imaging system for that purpose have recently begun to appear. The prospects and challenges for future integration of animal and human studies are discussed.
The neural basis for temporal integration of visual information in short term memory. We investigated the neural basis of integration of temporally separated bilateral asymmetrical dot patterns by using functional magnetic resonance imaging (fMRI). A symmetrical dot pattern with a small asymmetric region was temporally separated into two patterns and presented sequentially. The participants were asked to find the asymmetrical region by temporally integrating the patterns. When the second array was presented after a brief (40ms) or a long (2560ms) interval the performance was good. However, the performance declined when the interval was intermediate (160ms). For all stimulus onset asynchrony (SOA) conditions the prefrontal cortex and the posterior parietal cortex were activated. For the Long SOA condition the superior parietal lobule was strongly activated. Furthermore, the inferior temporal gyrus, which is involved in form perception and object recognition, was activated. This result suggested that the dot patterns would be encoded in visual short term memory as global figures.
Near-infrared spectroscopy (NIRS) is attracting growing interest as a powerful tool for monitoring cortical activation associated with various psychological phenomena. Many NIRS studies have aimed to explore brain functions associated with visual perception. However, how NIRS can monitor hemodynamic responses in the visual cortex corresponding to stimulation of each visual quadrant is not well known. Here we measured changes in concentration of oxygenated hemoglobin and deoxygenated hemoglobin in the human visual cortex with a 24-ch NIRS instrument. Through individual stimulation of visual quadrants we found that NIRS could differentially monitor activation of the left and right hemisphere when the lower visual field was stimulated, but hardly detected activation of both hemispheres when the upper visual field was stimulated. The result of fMRI scans using the same stimuli suggests that the different measurement responses to upper- and lower visual field stimulation are caused by the differences in the depth from the scalp of the region representing each visual field. On the basis of the present results, we discuss the limitations and potential of NIRS measurements.
Our aim was to predict the duration of a stimulus, which was a tone or a gap in a continuous tone, from auditory event-related brain potentials (neural decoding). We also aimed to compare performances across statistical classification methods for prediction. We found that the decoder performance was significantly higher than the chance level. The naive Bayes method with principal-component-analysis preprocessing (PCA+NB classification) and the support-vectormachine method (SVM classification) revealed a higher performance than the naive-Bayes method (NB classification) alone. Erroneous classifications were distributed in the neighborhood of the correct class. It is suggested that the SVM method has an advantage for its high performance without parameter optimization, while the PCA+NB method has an advantage for clarifying brain representation. Statistical classification is thus shown to be an effective method for analyzing an EEG and could be useful for investigating neural representation of sensory input.
The neural basis of dual-tasking, including simultaneous, overlapping, and successive dual-tasking, is discussed. There are three main points. The first is concerned with the neural correlates of executive functions, such as resource allocation and task management in dual-tasking. The roles of the prefrontal regions are discussed, as well as the possibility that the executive functions might emerge as interactions of the posterior brain regions. Second, multiple functions of the inferior frontal regions are discussed in terms of temporal order coordination, working memory, and language. The possibility that they might be related to a central bottle-neck in information processing is also discussed. The third point is related to the reduction of activation in the posterior brain regions during dual-tasking, as well as its implication in resource limitation in human cognition and dual-task interference.
There are two fundamental principles of functional organization in the human brain: functional specialization, and integration. Functional specialization assumes a local specialization for certain aspects of information processing. However, this view cannot characterize how local areas interact with each other. The other view, functional integration within a system, is able to address and characterize this issue in terms of effective connectivity. Effective connectivity is defined as the causal influences that neural units exert over another. This view is gradually gaining importance in the study of functional neuroimaging. The present article at first introduced four types of dynamic systems that are framed in terms of analyses of functional and effective connectivity. It then focused on dynamical causal modelling (DCM). The conceptual and mathematical basis of DCM are reviewed. The key advantage of DCM is that it allows for generating plausible models of neural population dynamics, and uses a biophysical forward model that describes the transformation from neural activity to hemodynamic response. A Bayesian model selection procedure is an additional benefit. Finally, notions for the usage of DCM have been described.
A previous study (Quinn and others, 2002) has indicated that infants reared by a mother preferred female faces to male faces. This preference would be made through the infants' experiences of faces. In order to test any cultural differences, the present study investigated the preferences of Japanese infants for female faces. In Experiment 1, each infant was presented with two faces in six preference trials of 10 seconds duration. The two stimuli were randomly selected from three facial stimuli: an average female, an average male, and an androgyne. The results revealed that the infants did not prefer a feminine face. In Experiment 2 distinctive faces were made using a morphing system to create new face stimuli: a '125% hypermale', a '125% hyperfemale', a '75% hypermale' and a '75% hyperfemale'. Each infant was presented with each pair of the four stimuli in four preference trials of 20 seconds duration. The results revealed that infants of 5-6 months preferred the feminine face in the female face condition, but infants of 3-4 and 7-8 months did not have any preference. In addition, to investigate the influence of contrast sensitivity we used inverted face stimuli. A preference for any inverted face was not displayed by any infant. These results suggest that infants of 5-6 months are capable of discriminating female faces.
In the late 1990s, the American Psychological Association advocated improved statistical practices, including reporting confidence intervals (CIs) and effect sizes. Since this statistical reform, the numbers of reports in international academic journals of psychology which have included the CI and effect sizes have increased. We investigated the evidence for statistical reform in Japan by examining papers published from 1982 to 2008 in the Japanese Journal of Psychonomic Science. The reports which included CIs and effect sizes were extremely rare in the journal even after 2001. This observation suggests that this statistical reform has not yet started among Japanese researchers in psychology.
Along with color, depth and motion, brightness is a fundamental quality of vision, and understanding the neural mechanisms of brightness perception is a topic of intense interest and controversy, both historically and in contemporary vision research. With few exceptions, modern textbooks still promote the fiction that brightness induction (e.g., simultaneous brightness contrast) results from lateral inhibition in isotropic filters, such as the circularly-concentric fields found in the retina. However, because brightness induction occurs over visual angles far in excess of the dimensions of individual retinal receptive fields (up to 10 degrees visual angle), "fill-in" accounts of brightness were proposed based on cortical mechanisms. A second historical challenge to retinal accounts of brightness induction was White's effect, in which the brightness of mid-gray patches situated on the dark and bright bars of a square-wave grating was opposite to that predicted by the output of circularly-concentric receptive fields. White's effect was a watershed event which caused spatial filtering accounts of brightness to be abandoned, and encouraged the development of high-level theories of brightness perception based largely on Helmholtzian idea of "unconscious inference". Through 25 year of systematic analysis of the grating induction effect Barbara Blakeslee and I have developed a "second-generation" theory of brightness perception which is based on oriented multi-scale spatial filtering which incorporates well-known properties of early cortical processing such as contrast normalization. We have recently applied the ODOG model to evaluate "anchoring" as an explanation of lightness perception, with the goal of clarifying and synthesizing the understanding of brightness and lightness.
Shiro Morinaga (1908-1964) studied optical illusions under the guidance of Koreshige Masuda at the Tokyo Imperial University and then went to Frankfurt a. M. to investigate perceptual problems including the factor of Ebenbreite (equal width) from 1935 to 1939 under W. Metzger. He also studied experimental aesthetics at the laboratory of E. Rubin, Copenhagen one year. He came back to Japan and worked on perception and performance of brain injured veterans at Shimofusa Sanatorium for several years. From 1949, he taught as a professor at the Chiba University until his death in 1964. He studied various perceptual problems including perceptual transparency, optical illusions, constancy, absolute judgments from the Gestalt point of view, especially theory of system of references. Many of his former students became active researchers.
Experimental phenomenology is a fundamental procedure of scientific research, not using any special tool or machine but by simple, direct and precise observation. Shiro Morinaga was a great experimental phenomenologist on visual perception in Japan and famous by his many extraordinal articles. For instance, on the illusion of concentric circles (Delboeuf areal illusion), he noticed that the largest illusionary effect has been produced when the ratio of the diameter of two circles was at the 3:2 ratio and pointed out that "assimilation-contrast effect" is arranged if two circles are perceived as one pattern or two dissociate parts. The author who has believed the manner of investigation of Morinaga, from the standpoint "visual space is essentially tridimensional and changing constantly," demonstrated that the perception of a cube is firstly materialized by 6 planes, next by 8 points and 12 straight lines, by observation of the rotating 6 random-dotted planes. Tridimensional object is not completely perceived from a fixed viewpoint, but by total movement of an object.
In memory of Professor Shiro Morinaga (1908-1964) his research and teaching at Chiba University are reviewed. The experimental studies by Professor Morinaga and his coworkers are discussed, with a short review of the historical background of the study on the Bezugssystem (system of reference). The textbooks used in his seminar classes are also introduced, e.g., Studien zur experimentellen Psychologie by David Katz (1953).
Four experiments examined temporal properties of audiovisual multisensory integration. Experiment 1 measured reaction time to 100ms auditory (A) and visual (V) stimuli, and to audiovisual (AV) combinations with stimulus onset asynchronies (SOAs) ranging from -100 to +200ms. Significant violations of Miller's inequality (signifying neural coactivation) occurred only for simultaneous presentation (AV SOA=0ms). Experiments 2 and 3 were identical to Experiment 1 with the following exceptions. In Experiment 2 auditory stimulus intensity was adjusted to clamp performance in auditory-only trials at a d'=2, while visual stimulus contrast was clearly suprathreshold (d'>4). The results indicated that neural coactivation occurred over an expanded range of AV SOAs from -60 to 0ms. In Experiment 3 visual stimulus contrast was adjusted to clamp performance in visual-only trials at a d'=2, while auditory stimulus intensity was clearly suprathreshold (d'>4). Neural coactivation in this case also occurred over an expanded range of AV SOAs, from 0 to +60ms. In Experiment 4 the intensity of both A and V stimuli was adjusted to clamp performance in unisensory trials at a d'=2. As in Experiment 1, neural coactivation occurred only for simultaneous AV presentation (AV SOA=0ms). These results have implications for early multisensory processing, the role of attention, and the generality of the inverse effectiveness rule.
Focusing on the topics of event perception and self-motion perception, in this paper, I introduce our recent research on the integration of visual information with auditory and vestibular information. We have been investigating the limits of audio/visual integration by modifying conventional stream/bounce displays in spatial and temporal domains. We found that a sound has a markedly. greater organizing influence on visual perception than was previously thought, influencing the resolution of visual motion sequences over a wide range of spatiotemporal manipulations. Regarding the integration of visual and vestibular information in perceived self-motion, the results of our experiments, in which we manipulated the congruency between vestibular and visual (optic flow) inputs, suggest that the multimodal integration is an either-or process when the discrepancy between visual and vestibular information is large, but the integration is a weighted combination of both inputs when that difference is small.
Large-field moving visual stimuli have long been known to be capable of inducing compelling illusions of self-motion ("vection") in stationary observers. Traditionally, the origin of such visually induced self-motion illusions has been attributed to low-level, bottom-up perceptual processes without much cognitive/higher-level contribution. In the last years, however, this view has been challenged, and an increasing number of studies has investigated potential higher-level/cognitive contributions. This paper aims at providing a concise review and discussion of one of these aspects: Does the cognitive framework of whether or not actual movement is possible affect illusory self-motion? Despite a variety of different approaches, there is growing evidence that both cognitive and perceptual information indicating movability can facilitate self-motion perception, especially when combined. This has important implications for our understanding of cognitive/perceptual contributions to self-motion perception as well as the growing field of self-motion simulations and virtual reality, where the need for physical motion of the observer could be reduced by intelligent usage of cognitive/perceptual frameworks of movability.
In several studies, we used surveys and experimental methods to investigate the factors evoking consumers' sense of safety and feelings of nostalgia in relation to the mere exposure effect in consumer's ad processing. The first series of studies revealed that the frequent repetition of an ad increased familiarity, liking as well as the sense of safety of a product by mere exposure effect. However, prior risk information about the products suppressed those effects. The second series of studies found that nostalgia occurs in response to events that had a long time lag after having frequent repetition in the past. We found five steps of nostalgic ad processing using a structural equation modeling: (1) nostalgic predisposition, (2) perception of nostalgic triggers, (3) retrieval of past events and ad memory, (4) familiarity and positive mood on ad, and (5) intention of purchase. Finally, we discuss the function of nostalgia based on experiments of source monitoring and emotion associative memory using auditory or visual ad stimuli.
This paper reviews research on consumer psychology with emphasis on the topics of decision making process and presents recent research on consumer decision process from traditional and alternative framework. Consumer decision research has examined behavioral violations of rational choice theory such as expected utility theory. Whereas expected utility theory does not explain why people are often simultaneously attracted to both insurance and gambling, prospect theory as nonlinear utility theory explains risk seeking preference in loss situation as well as risk aversive preference in loss situation using value function. Contingent focus model also explains such phenomenon and predicts various behaviors which are different from prospect theory. Lastly, this review examines some of the studies in neuroeconomics as it relates to consumer decision process and offers future perspectives in consumer research.
Based on Ikeda et al. (2009), I discuss whether interpersonal differences in body mass are related to those in time discounting and its anomalies reported in behavioral economics. The effects of time discounting on body mass index (BMI) and the probabilities of being obese, severely obese, and underweight are detected by incorporating three properties regarding time discounting: (1) impatience, measured by the level of the respondents' discount rates; (2) hyperbolic discounting, where discount rates for the discounting of immediate future choices are higher than those for distant future choices; and (3) sign effects, wherein future negative payoffs are discounted at a lower rate than are future positive payoffs. The results imply that body mass is determined as an outcome of intertemporal decision makings, so that it can be affected by controlling in the intertemporal structure of medical care costs and the price of a calorie.
This study used a bistable plaid motion pattern to examine whether mood can modulate visual awareness. After either a happy or sad mood was induced the participants observed for three minutes a moving plaid pattern created by superimposing two gratings in different orientations. The participants indicated whether they perceived the motion pattern as two surfaces sliding in different directions (component motion) or as a single plaid pattern (pattern motion). The results revealed that participants in a happy mood reported longer durations of the component motion than those in sad or neutral induced mood. The results suggest that a happy mood enhances tracking multiple motion patterns whereas a sad or neutral mood leads to focused perception of a single object motion.
We examined the effect of preference for dot-patterns on dot-location memory. The participants were asked to recall the location memory of five dots (Experiment 1), seven dots (Experiment 2) and nine dots (Experiment 3) constituting each pattern. They then rated their preference for the dot-patterns on a five-point scale, from 'likable (1)' to 'dislikable (5)'. We classified the dot-patterns as likable, neutral and dislikable patterns, according to the preference rating scores. The results revealed that location memory performance of the likable and the neutral patterns was better than that of the dislikable patterns in Experiment 1, while there was no significant difference among the three preference classes in Experiment 2. Moreover, in Experiment 3, the performance for the dislikable patterns was the best. The results suggest that the effect of preference on dot-location memory depends on the number of the dots constituting the patterns.
When two targets (T1 and T2) are embedded in a rapid serial visual presentation, T2 is often missed if it appears within 500ms after T1 (attentional blink, AB). However, a T2 report is not impaired if it immediately follows T1 (Lag-1 sparing). Furthermore, in a three-target AB paradigm, the third target is also easily identified when the targets are presented successively (Lag-2 sparing). The present study examined how targets were consolidated in working memory when Lag-2 sparing occurred, by observing the P3 component of the event-related potential. Multiple P3 components elicited separately by each target were observed when Lag-2 sparing occurred, suggesting that the trailing targets can be consolidated independently.
This study investigated the perceptual factors that automatically activate spatially compatible responses. The task of each participant was to press a right or left response key according to the color of the central target. A visual (Experiment 1) or auditory (Experiment 2) task-irrelevant accessory stimulus commenced on, or was removed from, its left or right side. The responses were faster when the visual onset, visual offset, or auditory onset, occurred on the same side as the response. With an auditory accessory offset however, a reversed tendency was observed. When the response and the auditory offset were on opposite sides the responses were slightly faster than when they were on the same side. These results indicate that a transient change automatically activates a spatially compatible response in the visual modality whereas a sustained stimulation from an ongoing stimulus source is more important in the auditory modality. Our discussion concludes that this modality difference comes from the different spatial representations of these perceptual modalities.
We examined whether adult bantams (Gallus gallus domesticus) complete occluded parts of objects (amodal completion) using a visual search task. First, 3 bantams were trained to search for a punched red diamond (a target) among complete diamonds (distracters) displayed on a touch-sensitive monitor. Next, white squares accompanied each figure with a small gap of a fixed size. In the test, the location of the accompanying squares sometimes changed. In some trials, the white squares exactly covered, or "occluded", the punched portion of the target. All three bantams had no difficulty in searching for targets in this "occluded" condition. This result, and the demonstration by Forkman (1998) of hens' amodal completion of figures placed on a perspective background, suggest that the perspective cue may have an important role in amodal completion for this species, or perhaps for the avian species.
We examined whether the squirrel monkey can perceive Thompson's Thatcher illusion. In the experiment, the monkey was required to discriminate a target face from three kinds of distractor stimuli whose particular facial features were different from those of the target. Because both faces were tilted at angles of either 45, 135, 225, or 315 degrees, there were four combinations of upright and inverted face presentations. The results revealed that when both faces were inverted and the eyes of the distractor face were reversed from the target face, the monkey's discrimination learning was obstructed more than under other conditions. Thus, these results suggest that the squirrel monkey can perceive the Thatcher illusion. It seems reasonable to suppose that the monkey can utilize information about facial configuration.
We examined whether motion binding (Lorenceau & Shiffrar, 1992) could be induced by local motion information that is independent of form information. The stimulus was a square frame, which is known to induce a strong perception of motion binding. The square was composed of bars having a sinusoidal spatial luminance modulation, either static or dynamic along their length. The results showed that dynamic modulation facilitates motion binding, while static modulation inhibits the binding. These results indicate that the local motion information contributes to the binding independently from that of form information.
The distribution of cortical activity to radial expansion or contraction motion with adults and infants (3 to 4 months and 4 to 5 months of age) was examined by measuring steady-state visual evoked potentials with a high-density electrode array. A motion pattern which was either radial expansion or contraction was alternately presented with a pattern of random motion, and the mean amplitude of the fundamental harmonic component (F1) corresponding to the pattern alternation frequency (2Hz) was measured. The results indicated the adults showed greater activity to contraction than to expansion in the right parietal area. Although the older (but not the younger) infants also showed contraction bias, the bias was spread over the whole occipitoparietal area. These results suggest that in adults radial motion processing may be achieved by different neural mechanisms to those in infants.
In a visual apparent motion display, an abrupt change in the attributes of an object, such as its size, extends the time the changed object is visible (visible persistence) even after its physical termination. The aim of this study was to investigate whether an abrupt change in an attribute of contingent auditory stimuli can also alter the visible persistence of an object, and how it might do this. The results indicated that a visible persistence occurred for longer time when an abrupt change of tone was introduced into a sequence of constant tones presented synchronously with visual stimuli. This persistence was also longer than when no abrupt change was introduced or when auditory information was absent (Experiment 1). However, the effect was attenuated when it was difficult to attribute the auditory information to the moving visual objects (Experiment 2). These results suggest that the object representations underlying the visible persistence might be formed by multisensory integration of auditory and visual information.
The present study investigated whether visual information processing deteriorates during exposure to whole-body vibration (WBV). It focused on the frequency effects of the vibration on target color discrimination and target detection performance. Eight participants performed target color discrimination and target detection tasks with, and without, 5Hz and 16Hz sinusoidal vertical vibration at a magnitude of 1.0ms^<-2> r.m.s.. Their reaction times (RTs) as a function of inter-stimulus intervals (ISIs) between a fixation display and a target display were compared for three experimental blocks: baseline without vibration (0Hz); 5Hz vibration; and 16Hz vibration. In the target discrimination tasks the RTs during shorter ISIs in the 5Hz block were significantly briefer than during the 0Hz and 16Hz blocks. For target detection, on the other hand, no significant difference was found between the three experimental blocks. These results suggested that visual information processing (i.e., target color discrimination) could be improved during exposure to 5Hz sinusoidal vertical WBV.
The tactile perception of surface roughness can be modulated by sounds. Our previous study demonstrated that white noise altered the tactile perception of the roughness of abrasive paper having a specific particle size. In the present study, we investigated whether the congruity between tactile and auditory information could be a critical factor in influencing the tactile perception of roughness. The results revealed that when the information about roughness in the modalities was congruent, the sound modulated the tactile perception of roughness more saliently. The direction of roughness modulation depended on the sound intensity: loud sound increased the perceived tactile roughness, whereas soft sound decreased it.
Visual motion information passes through several distinct processing stages, but the stage where the perceptual limit of motion detection arises is still unknown. We tested how vertical illusory motion affects the detection of horizontal motion. We presented a central Gabor patch moving horizontally, together with a surrounding grating moving vertically. The central stimulus is perceived as moving obliquely by integration between the physical and illusory motion induced by the surrounding motion. The participants were asked to judge the horizontal motion component of the central stimulus (left vs. right). We found motion detection performance was enhanced at a moderate surrounding speed in comparison with baseline condition where the surrounding stimulus was statisnary. The results suggest that the later stage where motion integration and center-surround interaction appears, is critical for determining motion detection performance.