Event-related fMRI Experiment Research Articles

Beyond faces: the contribution of the amygdala to visual processing in the macaque brain.

The amygdala is present in a diverse range of vertebrate species, such as lizards, rodents, and primates; however, its structure and connectivity differs across species. The increased connections to visual sensory areas in primate species suggests that understanding the visual selectivity of the amygdala in detail is critical to revealing the principles underlying its function in primate cognition. Therefore, we designed a high-resolution, contrast-agent enhanced, event-related fMRI experiment, and scanned 3 adult rhesus macaques, while they viewed 96 naturalistic stimuli. Half of these stimuli were social (defined by the presence of a conspecific), the other half were nonsocial. We also nested manipulations of emotional valence (positive, neutral, and negative) and visual category (faces, nonfaces, animate, and inanimate) within the stimulus set. The results reveal widespread effects of emotional valence, with the amygdala responding more on average to inanimate objects and animals than faces, bodies, or social agents in this experimental context. These findings suggest that the amygdala makes a contribution to primate vision that goes beyond an auxiliary role in face or social perception. Furthermore, the results highlight the importance of stimulus selection and experimental design when probing the function of the amygdala and other visually responsive brain regions.

The effect of cognitive load on preference and intensity processing of sweet taste in the brain

Distracted eating can cause overconsumption. Whereas previous work has shown that cognitive load suppresses perceived taste intensity and increases subsequent consumption, the mechanism behind distraction-induced overconsumption remains unclear.To elucidate this, we performed two event-related fMRI experiments that examined how cognitive load affects neural responses and perceived intensity and preferred intensity, respectively, to solutions varying in sweetness. In Experiment 1 (N = 24), participants tasted weak sweet and strong sweet glucose solutions and rated their intensity while we concurrently varied cognitive load using a digit-span task. In Experiment 2 (N = 22), participants tasted five different glucose concentrations under varying cognitive load and then indicated whether they wanted to keep, decrease or increase its sweetness.Participants in Experiment 1 rated strong sweet solutions as less sweet under high compared to low cognitive load, which was accompanied by attenuated activation the right middle insula and bilateral DLPFC. Psychophysiological interaction analyses showed that cognitive load moreover altered connectivity between the middle insula and nucleus accumbens and DLPFC and middle insula while tasting strong sweet solutions.In Experiment 2, cognitive load did not affect participants’ preferred sweetness intensity. fMRI results revealed that cognitive load attenuated DLPFC activation for the strongest sweet solutions in the study.In conclusion, our behavioral and neuroimaging results suggest that cognitive load dampens the sensory processing of strong sweet solutions in particular, which may indicate higher competition for attentional resources for strong sweet than weak sweet solutions under high cognitive load. Implications for future research are discussed.

A frontoparietal network for volitional control of gaze following.

Gaze following is a major element of non-verbal communication and important for successful social interactions. Human gaze following is a fast and almost reflex-like behavior, yet, it can be volitionally controlled and suppressed to some extent if inappropriate or unnecessary, given the social context. In order to identify the neural basis of the cognitive control of gaze following, we carried out an event-related fMRI experiment, in which human subjects' eye movements were tracked while they were exposed to gaze cues in two distinct contexts: a baseline gaze following condition in which subjects were instructed to use gaze cues to shift their attention to a gazed-at spatial target and a control condition in which the subjects were required to ignore the gaze cue and instead to shift their attention to a distinct spatial target to be selected based on a color mapping rule, requiring the suppression of gaze following. We could identify a suppression-related BOLD response in a frontoparietal network comprising dorsolateral prefrontal cortex (dlPFC), orbitofrontal cortex (OFC), the anterior insula, precuneus and posterior parietal cortex (PPC). These findings suggest that over excitation of frontoparietal circuits in turn suppressing the gaze following patch might be a potential cause of gaze following deficits in clinical populations.

Neural correlates of emotional valence for faces and words.

Stimuli with negative emotional valence are especially apt to influence perception and action because of their crucial role in survival, a property that may not be precisely mirrored by positive emotional stimuli of equal intensity. The aim of this study was to identify the neural circuits differentially coding for positive and negative valence in the implicit processing of facial expressions and words, which are among the main ways human beings use to express emotions. Thirty-six healthy subjects took part in an event-related fMRI experiment. We used an implicit emotional processing task with the visual presentation of negative, positive, and neutral faces and words, as primary stimuli. Dynamic Causal Modeling (DCM) of the fMRI data was used to test effective brain connectivity within two different anatomo-functional models, for the processing of words and faces, respectively. In our models, the only areas showing a significant differential response to negative and positive valence across both face and word stimuli were early visual cortices, with faces eliciting stronger activations. For faces, DCM revealed that this effect was mediated by a facilitation of activity in the amygdala by positive faces and in the fusiform face area by negative faces; for words, the effect was mainly imputable to a facilitation of activity in the primary visual cortex by positive words. These findings support a role of early sensory cortices in discriminating the emotional valence of both faces and words, where the effect may be mediated chiefly by the subcortical/limbic visual route for faces, and rely more on the direct thalamic pathway to primary visual cortex for words.

Spatially Adjacent Regions in Posterior Cingulate Cortex Represent Familiar Faces at Different Levels of Complexity.

Extensive research has shown that perceptual information of faces is processed in a network of hierarchically-organized areas within ventral temporal cortex. For familiar and famous faces, perceptual processing of faces is normally accompanied by extraction of semantic knowledge about the social status of persons. Semantic processing of familiar faces could entail progressive stages of information abstraction. However, the cortical mechanisms supporting multistage processing of familiar faces have not been characterized. Here, using an event-related fMRI experiment, familiar faces from four celebrity groups (actors, singers, politicians, and football players) and unfamiliar faces were presented to the human subjects (both males and females) while they were engaged in a face categorization task. We systematically explored the cortical representations for faces, familiar faces, subcategories of familiar faces, and familiar face identities using whole-brain univariate analysis, searchlight-based multivariate pattern analysis (MVPA), and functional connectivity analysis. Convergent evidence from all these analyses revealed a set of overlapping regions within posterior cingulate cortex (PCC) that contained decodable fMRI responses for representing different levels of semantic knowledge about familiar faces. Our results suggest a multistage pathway in PCC for processing semantic information of faces, analogous to the multistage pathway in ventral temporal cortex for processing perceptual information of faces.SIGNIFICANCE STATEMENT Recognizing familiar faces is an important component of social communications. Previous research has shown that a distributed network of brain areas is involved in processing the semantic information of familiar faces. However, it is not clear how different levels of semantic information are represented in the brain. Here, we evaluated the multivariate response patterns across the entire cortex to discover the areas that contain information for familiar faces, subcategories of familiar faces, and identities of familiar faces. The searchlight maps revealed that different levels of semantic information are represented in topographically adjacent areas within posterior cingulate cortex (PCC). The results suggest that semantic processing of faces is mediated through progressive stages of information abstraction in PCC.

Preference for locomotion-compatible curved paths and forward direction of self-motion in somatomotor and visual areas

During locomotion, leg movements define the direction of walking (forward or backward) and the path one is taking (straight or curved). These aspects of locomotion produce characteristic visual motion patterns during movement. Here, we tested whether cortical regions responding to either egomotion-compatible visual motion, or leg movements, or both, are sensitive to these locomotion-relevant aspects of visual motion. We compared a curved path (typically the visual feedback of a changing direction of movement in the environment) to a linear path for simulated forward and backward motion in an event-related fMRI experiment. We used an individual surface-based approach and two functional localizers to define (1) six egomotion-related areas (V6+, V3A, intraparietal motion area [IPSmot], cingulate sulcus visual area [CSv], posterior cingulate area [pCi], posterior insular cortex [PIC]) using the flow field stimulus and (2) three leg-related cortical regions (human PEc [hPEc], human PE [hPE] and primary somatosensory cortex [S–I]) using a somatomotor task. Then, we extracted the response from all these regions with respect to the main event-related fMRI experiment, consisting of passive viewing of an optic flow stimulus, simulating a forward or backward direction of self-motion in either linear or curved path. Results showed that some regions have a significant preference for the curved path motion (hPEc, hPE, S–I, IPSmot) or a preference for the forward motion (V3A), while other regions have both a significant preference for the curved path motion and for the forward compared to backward motion (V6+, CSv, pCi). We did not find any significant effects of the present stimuli in PIC. Since controlling locomotion mainly means controlling changes of walking direction in the environment during forward self-motion, such a differential functional profile among these cortical regions suggests that they play a differentiated role in the visual guidance of locomotion.

Boys’ toys, girls’ toys: An fMRI study of mothers’ neural responses to children violating gender expectations

This study examined 1) mothers’ neural responses to pictures of boys and girls who confirmed or violated social expectations regarding toy preferences, and 2) whether neural sensitivity to targets that violated gendered expectations interacted with mothers’ gender stereotypes. In an event-related fMRI experiment, 23 mothers of a 2–6 year-old child viewed and evaluated pictures of boys or girls with their favorite toy. Next, mothers gender stereotypes about children’s toys and behavior, and internal motivation to behave without prejudice were assessed. Several neural processes were underlying parents’ responses to children’s behavior that violates gender-role expectations. Brain regions involved in mentalizing or storage of social knowledge, understanding goal-directed behavior, behavioral control, and conflict monitoring were activated when viewing child targets that violated gender expectations. In these brain areas, increased neural responses to targets that violated traditional gender expectations were associated with more stereotyped expectations about boys’ and girls’ toys and behavior.

Producing regularly and irregularly inflected verb forms: behavioural and neuroimaging data from the three Italian conjugations

ABSTRACTThe generation of regular and irregular inflected verb-forms has been taken as a crucial test between models of inflection in the mental lexicon, namely approaches which invoke different mechanisms for regular and irregular forms (rule-based procedures vs. recovery of whole forms stored in an associative network) and accounts which postulate a single procedure for all forms. An alternative hypothesis suggests that inflectional processes are explained by membership of words to clusters, for instance, Italian inflectional classes (conjugations). In a behavioural and a rapid event-related fMRI experiment, participants overtly generated the past participle of verbs from the three Italian conjugations. Results showed that the cognitive operations and the neural substrate underlying inflectional processes rely on specific properties of inflectional classes. Different patterns of cortical activations elicited by verbs from different conjugations were detected for the first time in the left middle frontal gyrus, left pre-supplementary motor area and left anterior cingulate cortex.

Left perirhinal cortex codes for semantic similarity between written words defined from cued word association

Knowledge of visual and nonvisual attributes of concrete entities is distributed over neocortical uni- and polymodal association cortex. Here we investigated the role of left perirhinal cortex in explicit knowledge retrieval from written words. We examined whether it extended across visual and nonvisual properties, animate and inanimate entities, how this differed from picture input and how specific it was for perirhinal cortex compared to surrounding structures. The semantic similarity between stimuli was determined on the basis of a word association-based model. Eighteen participants participated in this event-related fMRI experiment. During property verification, the left perirhinal cortex coded for the similarity in meaning between written words. No differences were found between visual and nonvisual properties or between animate and inanimate entities. Among the surrounding regions, a semantic similarity effect for written words was also present in the left parahippocampal gyrus, but not in the hippocampus nor in the right perirhinal cortex. Univariate analysis revealed higher activity for visual property verification in visual processing regions and for nonvisual property verification in an extended system encompassing the superior temporal sulcus along its anterior-posterior axis, the inferior and the superior frontal gyrus. The association strength between the concept and the property correlated positively with fMRI response amplitude in visual processing regions, and negatively with response amplitude in left inferior and superior frontal gyrus. The current findings establish that input-modality determines the semantic similarity effect in left perirhinal cortex more than the content of the knowledge retrieved or the semantic control demand do. We propose that left perirhinal cortex codes for the association between a concrete written word and the object it refers to and operates as a connector hub linking written word input to the distributed cortical representation of word meaning.

An fMRI-study on single-sided deafness: Spectral-temporal properties and side of stimulation modulates hemispheric dominance.

ObjectiveOur main aim was to investigate the blood oxygenation level dependent (BOLD) response to monaural and binaural speech- and non-speech stimuli as measured with fMRI in subjects with single-sided deafness and in normal hearing controls. We hypothesised that the response to monaural stimulation in both normal hearing subjects and persons with single-sided deafness would vary with the complexity and nature of the stimuli and the side of stimulation.DesignPatients with left- and right single-sided deafness and controls with normal hearing receiving either binaural or monaural stimuli were tested using speech and non-speech auditory stimuli in an event-related fMRI experiment.Study sampleTwenty-two patients with single-sided deafness after treatment for vestibular schwannoma and 50 normal hearing controls.ResultsNormal hearing persons receiving right side monaural stimuli activate bilateral temporal regions. Activation following left side monaural stimulation is more right lateralized. Persons with single-sided deafness respond similarly to controls to monaural stimulation. Persons with right side single-sided deafness show activation of frontal cortical regions not seen in persons with left side single-sided deafness following speech stimuli. This is possibly related to increased effort and more frequently reported problems with communication. Right side single-sided deafness is related to increased activation of areas usually related to processing of degraded input, including the thalamus.ConclusionHemispheric dominance following monaural auditory stimulation is modulated by the spectral-temporal properties of the stimuli and by which ear is stimulated. Differences between patients with right- and left side deafness suggests that right side deafness is related to increased activation of areas involved in processing of degraded input.

Unraveling the spatiotemporal brain dynamics during a simulated reach-to-eat task

The reach-to-eat task involves a sequence of action components including looking, reaching, grasping, and feeding. While cortical representations of individual action components have been mapped in human functional magnetic resonance imaging (fMRI) studies, little is known about the continuous spatiotemporal dynamics among these representations during the reach-to-eat task. In a periodic event-related fMRI experiment, subjects were scanned while they reached toward a food image, grasped the virtual food, and brought it to their mouth within each 16-s cycle. Fourier-based analysis of fMRI time series revealed periodic signals and noise distributed across the brain. Independent component analysis was used to remove periodic or aperiodic motion artifacts. Time-frequency analysis was used to analyze the temporal characteristics of periodic signals in each voxel. Circular statistics was then used to estimate mean phase angles of periodic signals and select voxels based on the distribution of phase angles. By sorting mean phase angles across regions, we were able to show the real-time spatiotemporal brain dynamics as continuous traveling waves over the cortical surface. The activation sequence consisted of approximately the following stages: (1) stimulus related activations in occipital and temporal cortices; (2) movement planning related activations in dorsal premotor and superior parietal cortices; (3) reaching related activations in primary sensorimotor cortex and supplementary motor area; (4) grasping related activations in postcentral gyrus and sulcus; (5) feeding related activations in orofacial areas. These results suggest that phase-encoded design and analysis can be used to unravel sequential activations among brain regions during a simulated reach-to-eat task.

A low-cost open-architecture taste delivery system for gustatory fMRI and BCI experiments

BackgroundTasting is a complex process involving chemosensory perception and cognitive evaluation. Different experimental designs and solution delivery approaches may in part explain the variability reported in literature. These technical aspects certainly limit the development of taste-related brain computer interface devices. New MethodWe propose a novel modular, scalable and low-cost device for rapid injection of small volumes of taste solutions during fMRI experiments that gathers the possibility to flexibly increase the number of channels, allowing complex multi-dimensional taste experiments. We provide the full description of the hardware and software architecture and illustrate the application of the working prototype in single-subject event-related fMRI experiments by showing the BOLD responses to basic taste qualities and to five intensities of tastes during the course of perception. ResultsThe device is shown to be effective in activating multiple clusters within the gustatory pathway and a precise time-resolved event-related analysis is shown to be possible by the impulsive nature of the induced perception. Comparison with Existing Method(s)This gustometer represents the first implementation of a low-cost, easily replicable and portable device that is suitable for all kinds of fMRI taste experiments. Its scalability will boost the experimental design of more complex multi-dimensional fMRI studies of the human taste pathway. ConclusionsThe gustometer represents a valid open-architecture alternative to other available devices and its spread and development may contribute to an increased standardization of experimental designs in human fMRI studies of taste perception and pave the way to the development of novel taste-related BCIs.

Catastrophizing and chronic low back pain: A functional magnetic resonance study

Pain depends on the interaction of cognitive, and emotional factors. Individuals with negative coping strategies such as catastrophizing are prone to develop chronic pain syndromes, and poor functional outcomes. This maladapted behavior may be caused by abnormalities in attention systems and amplification of pain processing. Low back pain (LBP) is a disabling pain syndrome, but it is poorly known how catastrophizing affects brain activity. To explore catastrophizing neural correlates in LBP, we performed an fMRI study to verify the central pain system (pain matrix), and anticipation responses. Under unpredictable stimuli, we expected to see catastrophizing LBP showing lower ability to disengage attention to pain and lower pain threshold. We studied 43 LBP and 27 C subjects. LBP responded catastrophizing questionnaires (FABQ, CSQ). We used a pressure-pain device, to deliver stimuli in the thumbnail. Pain thresholds detected a priori, for moderate pain. Subjects performed 2 event-related fMRI experiments: 1 - Supraliminal Pain for the pain matrix study; 2 – Variable Pain for anticipation at unpredictable stimuli. T2* images acquired in a 3 T Siemens scanner. FMRI data was preprocessed and carried out using FSL tool. Corrected cluster significance threshold: P = 0.05. Both groups were similar for demographics. LBP had lower threshold for pressure stimulus. Both groups activated pain matrix areas, and had the same pattern during anticipation. When covarying with FABQ during experiment 2, LBP showed greater posterior cingulate cortex activation, indicating that in LBP, FABQ reduces brain activity. LBP had lower pain threshold, suggesting central sensitization. Although both groups activated the pain matrix and had the same anticipation pattern, catastrophizing LBP had decreased activity in posterior cingulate cortex, suggesting negative coping skill influences pain appraisal in anticipation. The area belongs to the attention system and antinociception pathways in healthy subjects. Our results are in line with previous data showing greater posterior cingulate activity in low catastrophizers.

Representational differences between line drawings and photographs of natural scenes: A dissociation between multi-voxel pattern analysis and repetition suppression

Distributed representations of scene categories are consistent between color photographs (CPs) and line drawings (LDs) in the parahippocampal place area (PPA) and the retrosplenial cortex (RSC), as shown using multi-voxel pattern analysis (MVPA). Here, we used repetition suppression (RS) to further investigate the degree of representational convergence between CPs and LDs of natural scenes. MVPA and RS can capture different aspects of visual representations, and RS may prove useful in elucidating important differences in the representations of CPs and LDs of natural scenes. We performed an event-related fMRI experiment, including image-repetitions either within-type (i.e., CP to CP or LD to LD) or between-types (CP to LD, LD to CP). We found significant RS for within-type repetitions in PPA, RSC and the occipital place area (OPA), but did not observe RS for between-types repetitions. By contrast, scene categories were decodable from activity patterns evoked by both CPs and LDs using SVM classification for both within-type decoding and between-types cross-decoding. We conclude that there are representational differences between CPs and LDs in scene-selective cortex despite a category-level correspondence.

Phantom Acupuncture Induces Placebo Credibility and Vicarious Sensations: A Parallel fMRI Study of Low Back Pain Patients

Although acupuncture is an effective therapeutic intervention for pain reduction, the exact difference between real and sham acupuncture has not been clearly understood because a somatosensory tactile component is commonly included in the existing sham acupuncture protocols. In an event-related fMRI experiment, we implemented a novel form of sham acupuncture, phantom acupuncture, that reproduces the acupuncture needling procedure without somatosensory tactile stimulation while maintaining the credibility of the acupuncture treatment context. Fifty-six non-specific low back pain patients received either real (REAL) or phantom (PHNT) acupuncture stimulation in a parallel group study. The REAL group exhibited greater activation in the posterior insula and anterior cingulate cortex, reflecting the needling-specific components of acupuncture. We demonstrated that PHNT could be delivered credibly. Interestingly, the PHNT-credible group exhibited bilateral activation in SI/SII and also reported vicarious acupuncture sensations without needling stimulation. The PHNT group showed greater activation in the bilateral dorsolateral/ventrolateral prefrontal cortex (dlPFC/vlPFC). Moreover, the PHNT group exhibited significant pain reduction, with a significant correlation between the subjective fMRI signal in the right dlPFC/vlPFC and a score assessing belief in acupuncture effectiveness. These results support an expectation-related placebo analgesic effect on subjective pain intensity ratings, possibly mediated by right prefrontal cortex activity.

Spatially generalizable representations of facial expressions: Decoding across partial face samples

A network of cortical and sub-cortical regions is known to be important in the processing of facial expression. However, to date no study has investigated whether representations of facial expressions present in this network permit generalization across independent samples of face information (e.g., eye region vs mouth region). We presented participants with partial face samples of five expression categories in a rapid event-related fMRI experiment. We reveal a network of face-sensitive regions that contain information about facial expression categories regardless of which part of the face is presented. We further reveal that the neural information present in a subset of these regions: dorsal prefrontal cortex (dPFC), superior temporal sulcus (STS), lateral occipital and ventral temporal cortex, and even early visual cortex, enables reliable generalization across independent visual inputs (faces depicting the ‘eyes only’ vs ‘eyes removed’). Furthermore, classification performance was correlated to behavioral performance in STS and dPFC. Our results demonstrate that both higher (e.g., STS, dPFC) and lower level cortical regions contain information useful for facial expression decoding that go beyond the visual information presented, and implicate a key role for contextual mechanisms such as cortical feedback in facial expression perception under challenging conditions of visual occlusion.

Abstract semantics in the motor system? – An event-related fMRI study on passive reading of semantic word categories carrying abstract emotional and mental meaning

Previous research showed that modality-preferential sensorimotor areas are relevant for processing concrete words used to speak about actions. However, whether modality-preferential areas also play a role for abstract words is still under debate. Whereas recent functional magnetic resonance imaging (fMRI) studies suggest an involvement of motor cortex in processing the meaning of abstract emotion words as, for example, ‘love’, other non-emotional abstract words, in particular ‘mental words’, such as ‘thought’ or ‘logic’, are believed to engage ‘amodal’ semantic systems only. In the present event-related fMRI experiment, subjects passively read abstract emotional and mental nouns along with concrete action related words. Contrary to expectation, the results indicate a specific involvement of face motor areas in the processing of mental nouns, resembling that seen for face related action words. This result was confirmed when subject-specific regions of interest (ROIs) defined by motor localizers were used. We conclude that a role of motor systems in semantic processing is not restricted to concrete words but extends to at least some abstract mental symbols previously thought to be entirely ‘disembodied’ and divorced from semantically related sensorimotor processing. Implications for neurocognitive theories of semantics and clinical applications will be highlighted, paying specific attention to the role of brain activations as indexes of cognitive processes and their relationships to ‘causal’ studies addressing lesion and transcranial magnetic stimulation (TMS) effects. Possible implications for clinical practice, in particular speech language therapy, are discussed in closing.

Recruitment of Foveal Retinotopic Cortex During Haptic Exploration of Shapes and Actions in the Dark

The role of the early visual cortex and higher-order occipitotemporal cortex has been studied extensively for visual recognition and to a lesser degree for haptic recognition and visually guided actions. Using a slow event-related fMRI experiment, we investigated whether tactile and visual exploration of objects recruit the same "visual" areas (and in the case of visual cortex, the same retinotopic zones) and if these areas show reactivation during delayed actions in the dark toward haptically explored objects (and if so, whether this reactivation might be due to imagery). We examined activation during visual or haptic exploration of objects and action execution (grasping or reaching) separated by an 18 s delay. Twenty-nine human volunteers (13 females) participated in this study. Participants had their eyes open and fixated on a point in the dark. The objects were placed below the fixation point and accordingly visual exploration activated the cuneus, which processes retinotopic locations in the lower visual field. Strikingly, the occipital pole (OP), representing foveal locations, showed higher activation for tactile than visual exploration, although the stimulus was unseen and location in the visual field was peripheral. Moreover, the lateral occipital tactile-visual area (LOtv) showed comparable activation for tactile and visual exploration. Psychophysiological interaction analysis indicated that the OP showed stronger functional connectivity with anterior intraparietal sulcus and LOtv during the haptic than visual exploration of shapes in the dark. After the delay, the cuneus, OP, and LOtv showed reactivation that was independent of the sensory modality used to explore the object. These results show that haptic actions not only activate "visual" areas during object touch, but also that this information appears to be used in guiding grasping actions toward targets after a delay.SIGNIFICANCE STATEMENT Visual presentation of an object activates shape-processing areas and retinotopic locations in early visual areas. Moreover, if the object is grasped in the dark after a delay, these areas show "reactivation." Here, we show that these areas are also activated and reactivated for haptic object exploration and haptically guided grasping. Touch-related activity occurs not only in the retinotopic location of the visual stimulus, but also at the occipital pole (OP), corresponding to the foveal representation, even though the stimulus was unseen and located peripherally. That is, the same "visual" regions are implicated in both visual and haptic exploration; however, touch also recruits high-acuity central representation within early visual areas during both haptic exploration of objects and subsequent actions toward them. Functional connectivity analysis shows that the OP is more strongly connected with ventral and dorsal stream areas when participants explore an object in the dark than when they view it.

Bilateral dorsal fronto-parietal areas are associated with integration of visual motion information and timed motor action

Interaction with the environment often involves situations requiring visuomotor integration. For instance, in fast interceptive actions, the brain must integrate visual information of motion with the appropriate motor action. In such dynamic situation, the brain may control movement based on predictions of where the object will be in the future and when it will arrive there. Although previous studies have analyzed brain regions associated with processing visual information of motion, motor control and visuomotor integration with static objects, less is known about visuomotor integration with moving objects. In the present study we used an event-related fMRI experiment to investigate brain areas integrating visual information of motion with motor action in response to moving objects. Twenty healthy volunteers performed an interceptive task where they had to press a button in synchrony with the arrival of a horizontally moving target at a predefined location. They also performed two control tasks—simple reaction and attention to visual motion—in order to identify and exclude brain areas that would be involved in motor or visual motion processing components that are inherent to interceptive tasks. Through a conjunction analysis, we show greater BOLD signal in a bilateral dorsal fronto-parietal network, as well as the intraparietal sulcus, angular gyrus, and human visual motion area hV5+. We discuss these results with respect to their previously identified functions, and suggest they play a role in visuomotor integration with moving objects.

20 Mazindol effect on cerebral response to nonverbal affective vocalisation in healthy individuals: an fmri study

Background/Aims Mazindol is known as one of the anorexiants for morbid obesity. According to previous study, the pharmacological property is similar to amphetamine, and this drug has an augmenting role of dopamine and serotonin by the inhibition of presynapse transporter. However, the neural basis of how mazindol acts on affective processing has been unclear. We investigated the cerebral response to nonverbal affective vocalisation to clarify the effect of mazindol by functional magnetic resonance imaging (fMRI). Methods 20 healthy subjects (11 males, 9 females: mean age: 28.2 years, SD=6.4) participated in this study. The study protocol was approved by the ethics committee of Nippon Medical School, and all subjects provided their informed consent. This experiment was performed by randomised controlled trial. Each subject underwent two fMRI experiments, taking either a placebo or 0.5 mg of mazindol 2 hours before the scan. For each subject, the two experiments were separated by at least 2 weeks. Event-related fMRI experiments were performed in this study. The subjects listened to 3 types of emotional sounds: happy, sad, and neutral sounds. Each subject judged whether the emotional valence was positive, negative, or neutral. Data analysis was performed by statistical parametric mapping (SPM8). Results As for fMRI accuracy, two-way repeated ANOVA (3 emotions×2 medications (placebo/mazindol)) showed no significant difference both in main effect of emotion (F (2, 76)=1.22, p>0.05), and in main effect of medication (placebo/mazindol: F (1, 38)=2.01, p>0.05). The fMRI experiment according to two-way repeated ANOVA showed significant difference both in main effect of emotion (F (2, 76)=60.7, p In cerebral response, two-way repeated ANOVA showed significant difference in main effect of emotion at the bilateral superior temporal gyrus, and left prefrontal gyrus (p Conclusion According to these results, cerebral function in vocal affective processing was changed by the action of madindol, especially in the area associated with dopaminergic neuron including medial frontal cortex and anterior cingulate.