Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
Add more filters










Publication year range
2.
J Clin Med ; 12(10)2023 May 17.
Article in English | MEDLINE | ID: mdl-37240627

ABSTRACT

Psychopathic traits in community and referred youths are strongly associated with severe externalizing problems and low prosocial behavior. However, less is known about the mechanisms that may link youth psychopathy and these outcomes. Social dominance orientation (SDO), defined as the general individual orientation toward unequal and dominant/subordinate relationships, might represent a valuable construct to explore to better understand the association between psychopathic traits, externalizing problems, and prosocial behavior. Based on this, the current study aimed to investigate the relationship between psychopathic traits, SDO, externalizing problems, and prosocial behavior in a community sample (N = 92, 45.57% females, mean age = 12.53, and SD = 0.60) and in a clinical (N = 29, 9% female, mean age = 12.57, and SD = 0.57) samples of adolescents with Oppositional Defiant Disorder or Conduct Disorder. Results showed that SDO mediated the relationship between psychopathic traits and externalizing problems and between psychopathic traits and prosocial behavior only in the clinical sample. These findings can provide valuable information on psychopathic trait correlates in youths with aggressive behavior disorders; treatment implications are discussed.

3.
Front Psychol ; 14: 1307467, 2023.
Article in English | MEDLINE | ID: mdl-38259544

ABSTRACT

The perception of material properties, which refers to the way in which individuals perceive and interpret materials through their sensory experiences, plays a crucial role in our interaction with the environment. Affordance, on the other hand, refers to the potential actions and uses that materials offer to users. In turn, the perception of the affordances is modulated by the aesthetic appreciation that individuals experience when interacting with the environment. Although material perception, affordances, and aesthetic appreciation are recognized as essential to fostering sustainability in society, only a few studies have investigated this subject matter systematically and their reciprocal influences. This scarcity is partially due to the challenges offered by the complexity of combining interdisciplinary topics that explore interactions between various disciplines, such as psychophysics, neurophysiology, affective science, aesthetics, and social and environmental sciences. Outlining the main findings across disciplines, this review highlights the pivotal role of material perception in shaping sustainable behaviors. It establishes connections between material perception, affordance, aesthetics, and sustainability, emphasizing the need for interdisciplinary research and integrated approaches in environmental psychology. This integration is essential as it can provide insight into how to foster sustainable and durable changes.

4.
Front Psychol ; 14: 1260396, 2023.
Article in English | MEDLINE | ID: mdl-38192392

ABSTRACT

Introduction: Guilt, shame, and embarrassment represent affective experiences with social implications and diverse self-relevant negative affect. While the distinction between these emotion terms has been extensively investigated, little is known about how they diverge and are related to each other and their crosscultural differences. Methods: Here, we used a community sample (N = 163) comprised of Americans and Italians and a scenario-based measure in which we asked participants to report the intensity of emotions that the story's main character would feel. The elements used to build the scenarios were based on a recent theoretical approach that proposes distinguishing cognitive, somatic, interoceptive, and behavioral ingredients to differentiate between these emotions. We hypothesized that these ingredients might effectively elicit the target emotions and that the main differences across these cultures would be associated with the emotion terms of shame/vergogna. Results: Our findings suggest that these defining elements are effective in evoking experiences of guilt, shame, and embarrassment. Moreover, we found that shame was equally elicited by the Shame and Guilt Scenarios only in the American sample, thus suggesting a proximity between shame and guilt in the American sample compared to the Italian's terms of vergogna and colpa. Discussion: These results suggest important implications for the psychology of moral emotions and highlight the importance of taking into account some cognitive factors, such as the quality of self-evaluation, the discrepancy between the actual self and the ideal self vs. the sense of perceived responsibility, and the different domains related to self-esteem.

5.
Front Psychiatry ; 13: 951925, 2022.
Article in English | MEDLINE | ID: mdl-36147968

ABSTRACT

Background: The therapeutic alliance has been recognized as one of the most researched key elements of treatment across different therapeutic approaches and diagnostic domains. Despite its importance, our current understanding of its clinical relevance in patients with obsessive-compulsive disorder (OCD) is still debated. This study aimed to examine empirical evidence on the effect of alliance on treatment outcomes in Cognitive Behavioral Therapy (CBT) in patients with OCD in a systematic review and meta-analysis. Methods: Original peer-reviewed articles until March 2022 were included if they were (1) written in English; (2) included a clinical group with a current primary OCD diagnosis; (3) involved individual CBT; (4) used a validated therapeutic alliance scale that was related to the outcome measurement; (5) reported an effect size. Results: Thirteen studies were included, six of which contained sufficient statistical information to be included in the meta-analysis. A total of 897 patients took part in all reviewed studies. We found a modest effect of alliance on post-treatment outcome [Tau 2 = -0.1562 (C.I. 95%: -0.2542 to -0.0582)]. Discussion: The results show the existence of considerable variability and methodological inconsistencies across studies. We discuss the role of methodological factors that could account for this divergence, the research limitations, and the implications for current research. Systematic review registration: [https://osf.io/dxez5/?view_only=bc2deaa7f0794c8dbef440255b2d4b3b].

6.
Brain Struct Funct ; 227(8): 2573-2592, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35963915

ABSTRACT

The human middle-temporal region MT+ is highly specialized in processing visual motion. However, recent studies have shown that this region is modulated by extraretinal signals, suggesting a possible involvement in processing motion information also from non-visual modalities. Here, we used functional MRI data to investigate the influence of retinal and extraretinal signals on MT+ in a large sample of subjects. Moreover, we used resting-state functional MRI to assess how the subdivisions of MT+ (i.e., MST, FST, MT, and V4t) are functionally connected. We first compared responses in MST, FST, MT, and V4t to coherent vs. random visual motion. We found that only MST and FST were positively activated by coherent motion. Furthermore, regional analyses revealed that MST and FST were positively activated by leg, but not arm, movements, while MT and V4t were deactivated by arm, but not leg, movements. Taken together, regional analyses revealed a visuomotor role for the anterior areas MST and FST and a pure visual role for the anterior areas MT and V4t. These findings were mirrored by the pattern of functional connections between these areas and the rest of the brain. Visual and visuomotor regions showed distinct patterns of functional connectivity, with the latter preferentially connected with the somatosensory and motor areas representing leg and foot. Overall, these findings reveal a functional sensitivity for coherent visual motion and lower-limb movements in MST and FST, suggesting their possible involvement in integrating sensory and motor information to perform locomotion.


Subject(s)
Motion Perception , Visual Cortex , Humans , Visual Cortex/physiology , Brain Mapping , Temporal Lobe/physiology , Motion Perception/physiology , Movement , Visual Pathways/physiology , Photic Stimulation
7.
Neuroimage ; 254: 119121, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35342004

ABSTRACT

Reconstructing natural images and decoding their semantic category from fMRI brain recordings is challenging. Acquiring sufficient pairs of images and their corresponding fMRI responses, which span the huge space of natural images, is prohibitive. We present a novel self-supervised approach that goes well beyond the scarce paired data, for achieving both: (i) state-of-the art fMRI-to-image reconstruction, and (ii) first-ever large-scale semantic classification from fMRI responses. By imposing cycle consistency between a pair of deep neural networks (from image-to-fMRI & from fMRI-to-image), we train our image reconstruction network on a large number of "unpaired" natural images (images without fMRI recordings) from many novel semantic categories. This enables to adapt our reconstruction network to a very rich semantic coverage without requiring any explicit semantic supervision. Specifically, we find that combining our self-supervised training with high-level perceptual losses, gives rise to new reconstruction & classification capabilities. In particular, this perceptual training enables to classify well fMRIs of never-before-seen semantic classes, without requiring any class labels during training. This gives rise to: (i) Unprecedented image-reconstruction from fMRI of never-before-seen images (evaluated by image metrics and human testing), and (ii) Large-scale semantic classification of categories that were never-before-seen during network training. Such large-scale (1000-way) semantic classification from fMRI recordings has never been demonstrated before. Finally, we provide evidence for the biological consistency of our learned model.


Subject(s)
Neural Networks, Computer , Semantics , Brain/diagnostic imaging , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods
8.
Brain Struct Funct ; 226(9): 2911-2930, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34043075

ABSTRACT

In humans, several neuroimaging studies have demonstrated that passive viewing of optic flow stimuli activates higher-level motion areas, like V6 and the cingulate sulcus visual area (CSv). In macaque, there are few studies on the sensitivity of V6 and CSv to egomotion compatible optic flow. The only fMRI study on this issue revealed selectivity to egomotion compatible optic flow in macaque CSv but not in V6 (Cotterau et al. Cereb Cortex 27(1):330-343, 2017, but see Fan et al. J Neurosci. 35:16303-16314, 2015). Yet, it is unknown whether monkey visual motion areas MT + and V6 display any distinctive fMRI functional profile relative to the optic flow stimulation, as it is the case for the homologous human areas (Pitzalis et al., Cereb Cortex 20(2):411-424, 2010). Here, we described the sensitivity of the monkey brain to two motion stimuli (radial rings and flow fields) originally used in humans to functionally map the motion middle temporal area MT + (Tootell et al. J Neurosci 15: 3215-3230, 1995a; Nature 375:139-141, 1995b) and the motion medial parietal area V6 (Pitzalis et al. 2010), respectively. In both animals, we found regions responding only to optic flow or radial rings stimulation, and regions responding to both stimuli. A region in the parieto-occipital sulcus (likely including V6) was one of the most highly selective area for coherently moving fields of dots, further demonstrating the power of this type of stimulation to activate V6 in both humans and monkeys. We did not find any evidence that putative macaque CSv responds to Flow Fields.


Subject(s)
Motion Perception , Optic Flow , Visual Cortex , Animals , Macaca , Magnetic Resonance Imaging , Photic Stimulation
9.
Front Psychol ; 11: 1676, 2020.
Article in English | MEDLINE | ID: mdl-32793053

ABSTRACT

Despite the remarkable advances in behavioral and brain sciences over the last decades, the mind-body (brain) problem is still an open debate and one of the most intriguing questions for both cognitive neuroscience and philosophy of mind. Traditional approaches have conceived this problem in terms of a contrast between physicalist monism and Cartesian dualism. However, since the late sixties, the landscape of philosophical views on the problem has become more varied and complex. The Multiple Realization Thesis (MRT) claims that mental properties can be (or are) realized, and mental processes can be (or are) implemented by neural correlates of different kinds. Thus, MRT challenges the psychoneural type-identity theory and the corresponding reductionism. Many philosophers have acknowledged the a priori plausibility of MRT. However, the existence of empirical evidence in favor of intraspecific, human multiple realizations of mental processes and properties is still controversial. Here, we illustrate some cases that provide empirical evidence in support of MRT. Recently, it has been proposed that foveal agnosic vision, like peripheral vision, can be restored by increasing object parts' spacing (Crutch and Warrington, 2007; Strappini et al., 2017b). Agnosic fovea and normal periphery are both limited by crowding, which impairs object recognition, and provides the signature of visual integration. Here, we define a psychological property of restored object identification, and we cross-reference the data of visually impaired patients with different etiologies. In particular, we compare the data of two stroke patients, two patients with posterior cortical atrophy, six cases of strabismic amblyopia, and one case with restored sight. We also compare these patients with unimpaired subjects tested in the periphery. We show that integration (i.e., restored recognition) seems to describe quite accurately the visual performance in all these cases. Whereas the patients have different etiologies and different neural correlates, the unimpaired subjects have no neural damage. Thus, similarity in the psychological property given the differences in the neural substrate can be interpreted in relation to MRT and provide evidence in its support. Finally, we will frame our contribution within the current debate concerning MRT providing new and compelling empirical evidence.

10.
Cereb Cortex ; 29(9): 3618-3635, 2019 08 14.
Article in English | MEDLINE | ID: mdl-30395164

ABSTRACT

A major limitation of conventional human brain research has been its basis in highly artificial laboratory experiments. Due to technical constraints, little is known about the nature of cortical activations during ecological real life. We have previously proposed the "spontaneous trait reactivation (STR)" hypothesis arguing that resting-state patterns, which emerge spontaneously in the absence of external stimulus, reflect the statistics of habitual cortical activations during real life. Therefore, these patterns can serve as a window into daily life cortical activity. A straightforward prediction of this hypothesis is that spontaneous patterns should preferentially correlate to patterns generated by naturalistic stimuli compared with artificial ones. Here we targeted high-level category-selective visual areas and tested this prediction by comparing BOLD functional connectivity patterns formed during rest to patterns formed in response to naturalistic stimuli, as well as to more artificial category-selective, dynamic stimuli. Our results revealed a significant correlation between the resting-state patterns and functional connectivity patterns generated by naturalistic stimuli. Furthermore, the correlations to naturalistic stimuli were significantly higher than those found between resting-state patterns and those generated by artificial control stimuli. These findings provide evidence of a stringent link between spontaneous patterns and the activation patterns during natural vision.


Subject(s)
Brain/physiology , Visual Perception/physiology , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/physiology , Photic Stimulation , Visual Cortex/physiology , Young Adult
11.
Hum Brain Mapp ; 39(7): 2868-2886, 2018 07.
Article in English | MEDLINE | ID: mdl-29536594

ABSTRACT

Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed-forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto-occipital areas including V1, LOC, V8/VO, and the motion-sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re-entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas.


Subject(s)
Brain Mapping/methods , Color Perception/physiology , Evoked Potentials, Visual/physiology , Visual Cortex/physiology , Adult , Contrast Sensitivity/physiology , Electroencephalography , Female , Humans , Magnetic Resonance Imaging , Male , Pattern Recognition, Visual/physiology , Visual Cortex/diagnostic imaging , Young Adult
12.
Sci Rep ; 7(1): 14848, 2017 11 01.
Article in English | MEDLINE | ID: mdl-29093537

ABSTRACT

Visual crowding is a perceptual phenomenon with far-reaching implications in both perceptual (e.g., object recognition and reading) and clinical (e.g., developmental dyslexia and visual agnosia) domains. Here, we combined event-related fMRI measurements and wide-field brain mapping methods to investigate whether the BOLD response evoked by visual crowding is modulated by different attentional conditions. Participants underwent two sessions of psychophysical training outside the scanner, and then fMRI BOLD activity was measured simultaneously in early visual areas (including the visual word form area, VWFA), while they viewed strongly-crowded and weakly-crowded Gabor patches in attended and unattended conditions. We found that crowding increased BOLD activity in a network of areas including V1, V2, V3A, V4/V8, and VWFA. In V4/V8 and VWFA we found an increased activity related to attention. The effect of crowding in V1 was recorded only when attention was fully devoted to the target location. Our results provide evidence that some area beyond V1 might be the likely candidate for the site of crowding, thus supporting the view of visual crowding as a mid-level visual phenomenon.


Subject(s)
Attention/physiology , Visual Cortex/physiology , Visual Perception/physiology , Brain Mapping/methods , Crowding , Evoked Potentials, Visual , Humans , Magnetic Resonance Imaging/methods
13.
Cortex ; 89: 135-155, 2017 04.
Article in English | MEDLINE | ID: mdl-28284488

ABSTRACT

Visual agnosia is a neuropsychological impairment of visual object recognition despite near-normal acuity and visual fields. A century of research has provided only a rudimentary account of the functional damage underlying this deficit. We find that the object-recognition ability of agnosic patients viewing an object directly is like that of normally-sighted observers viewing it indirectly, with peripheral vision. Thus, agnosic vision is like peripheral vision. We obtained 14 visual-object-recognition tests that are commonly used for diagnosis of visual agnosia. Our "standard" normal observer took these tests at various eccentricities in his periphery. Analyzing the published data of 32 apperceptive agnosia patients and a group of 14 posterior cortical atrophy (PCA) patients on these tests, we find that each patient's pattern of object recognition deficits is well characterized by one number, the equivalent eccentricity at which our standard observer's peripheral vision is like the central vision of the agnosic patient. In other words, each agnosic patient's equivalent eccentricity is conserved across tests. Across patients, equivalent eccentricity ranges from 4 to 40 deg, which rates severity of the visual deficit. In normal peripheral vision, the required size to perceive a simple image (e.g., an isolated letter) is limited by acuity, and that for a complex image (e.g., a face or a word) is limited by crowding. In crowding, adjacent simple objects appear unrecognizably jumbled unless their spacing exceeds the crowding distance, which grows linearly with eccentricity. Besides conservation of equivalent eccentricity across object-recognition tests, we also find conservation, from eccentricity to agnosia, of the relative susceptibility of recognition of ten visual tests. These findings show that agnosic vision is like eccentric vision. Whence crowding? Peripheral vision, strabismic amblyopia, and possibly apperceptive agnosia are all limited by crowding, making it urgent to know what drives crowding. Acuity does not (Song et al., 2014), but neural density might: neurons per deg2 in the crowding-relevant cortical area.


Subject(s)
Agnosia/diagnosis , Recognition, Psychology/physiology , Vision, Ocular/physiology , Visual Perception/physiology , Adolescent , Adult , Aged , Agnosia/physiopathology , Child , Female , Humans , Male , Middle Aged , Pattern Recognition, Visual/physiology , Vision Tests , Young Adult
14.
Hum Brain Mapp ; 38(3): 1438-1459, 2017 03.
Article in English | MEDLINE | ID: mdl-27943516

ABSTRACT

Temporal and spatial filtering of fMRI data is often used to improve statistical power. However, conventional methods, such as smoothing with fixed-width Gaussian filters, remove fine-scale structure in the data, necessitating a tradeoff between sensitivity and specificity. Specifically, smoothing may increase sensitivity (reduce noise and increase statistical power) but at the cost loss of specificity in that fine-scale structure in neural activity patterns is lost. Here, we propose an alternative smoothing method based on Gaussian processes (GP) regression for single subjects fMRI experiments. This method adapts the level of smoothing on a voxel by voxel basis according to the characteristics of the local neural activity patterns. GP-based fMRI analysis has been heretofore impractical owing to computational demands. Here, we demonstrate a new implementation of GP that makes it possible to handle the massive data dimensionality of the typical fMRI experiment. We demonstrate how GP can be used as a drop-in replacement to conventional preprocessing steps for temporal and spatial smoothing in a standard fMRI pipeline. We present simulated and experimental results that show the increased sensitivity and specificity compared to conventional smoothing strategies. Hum Brain Mapp 38:1438-1459, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Brain Mapping , Brain/diagnostic imaging , Magnetic Resonance Imaging/methods , Normal Distribution , Signal Processing, Computer-Assisted , Computer Simulation , Female , Humans , Image Processing, Computer-Assisted , Male , Models, Statistical , Reproducibility of Results , Sensitivity and Specificity
15.
Cereb Cortex ; 27(1): 750-763, 2017 01 01.
Article in English | MEDLINE | ID: mdl-26574501

ABSTRACT

In the absence of stimulus or task, the cortex spontaneously generates rich and consistent functional connectivity patterns (termed resting state networks) which are evident even within individual cortical areas. We and others have previously hypothesized that habitual cortical network activations during daily life contribute to the shaping of these connectivity patterns. Here we tested this hypothesis by comparing, using blood oxygen level-dependent-functional magnetic resonance imaging, the connectivity patterns that spontaneously emerge during rest in retinotopic visual areas to the patterns generated by naturalistic visual stimuli (repeated movie segments). These were then compared with connectivity patterns produced by more standard retinotopic mapping stimuli (polar and eccentricity mapping). Our results reveal that the movie-driven patterns were significantly more similar to the spontaneously emerging patterns, compared with the connectivity patterns of either eccentricity or polar mapping stimuli. Intentional visual imagery of naturalistic stimuli was unlikely to underlie these results, since they were duplicated when participants were engaged in an auditory task. Our results suggest that the connectivity patterns that appear during rest better reflect naturalistic activations rather than controlled, artificially designed stimuli. The results are compatible with the hypothesis that the spontaneous connectivity patterns in human retinotopic areas reflect the statistics of cortical coactivations during natural vision.


Subject(s)
Visual Cortex/physiology , Visual Perception/physiology , Adult , Brain Mapping , Cerebrovascular Circulation/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Motion Pictures , Oxygen/blood , Photic Stimulation , Rest , Visual Cortex/diagnostic imaging
16.
Brain Struct Funct ; 220(5): 2587-601, 2015 Sep.
Article in English | MEDLINE | ID: mdl-24942135

ABSTRACT

Even though the eyes constantly change position, the location of a stimulus can be accurately represented by a population of neurons with retinotopic receptive fields modulated by eye position gain fields. Recent electrophysiological studies, however, indicate that eye position gain fields may serve an additional function since they have a non-uniform spatial distribution that increases the neural response to stimuli in the straight-ahead direction. We used functional magnetic resonance imaging and a wide-field stimulus display to determine whether gaze modulations in early human visual cortex enhance the blood-oxygenation-level dependent (BOLD) response to stimuli that are straight-ahead. Subjects viewed rotating polar angle wedge stimuli centered straight-ahead or vertically displaced by ± 20° eccentricity. Gaze position did not affect the topography of polar phase-angle maps, confirming that coding was retinotopic, but did affect the amplitude of the BOLD response, consistent with a gain field. In agreement with recent electrophysiological studies, BOLD responses in V1 and V2 to a wedge stimulus at a fixed retinal locus decreased when the wedge location in head-centered coordinates was farther from the straight-ahead direction. We conclude that stimulus-evoked BOLD signals are modulated by a systematic, non-uniform distribution of eye-position gain fields.


Subject(s)
Brain Mapping , Eye/pathology , Fixation, Ocular/physiology , Magnetic Resonance Imaging , Visual Cortex/physiology , Visual Perception/physiology , Adult , Female , Humans , Male , Neurons/physiology , Photic Stimulation/methods
17.
PLoS One ; 7(4): e35771, 2012.
Article in English | MEDLINE | ID: mdl-22558222

ABSTRACT

Neuroimaging studies have identified several motion-sensitive visual areas in the human brain, but the time course of their activation cannot be measured with these techniques. In the present study, we combined electrophysiological and neuroimaging methods (including retinotopic brain mapping) to determine the spatio-temporal profile of motion-onset visual evoked potentials for slow and fast motion stimuli and to localize its neural generators. We found that cortical activity initiates in the primary visual area (V1) for slow stimuli, peaking 100 ms after the onset of motion. Subsequently, activity in the mid-temporal motion-sensitive areas, MT+, peaked at 120 ms, followed by peaks in activity in the more dorsal area, V3A, at 160 ms and the lateral occipital complex at 180 ms. Approximately 250 ms after stimulus onset, activity fast motion stimuli was predominant in area V6 along the parieto-occipital sulcus. Finally, at 350 ms (100 ms after the motion offset) brain activity was visible again in area V1. For fast motion stimuli, the spatio-temporal brain pattern was similar, except that the first activity was detected at 70 ms in area MT+. Comparing functional magnetic resonance data for slow vs. fast motion, we found signs of slow-fast motion stimulus topography along the posterior brain in at least three cortical regions (MT+, V3A and LOR).


Subject(s)
Evoked Potentials, Visual/physiology , Motion Perception/physiology , Visual Cortex/physiology , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Motion , Neuroimaging , Photic Stimulation , Space Perception/physiology , Time Perception/physiology , Visual Cortex/anatomy & histology , Visual Fields
18.
Hum Brain Mapp ; 33(6): 1334-51, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21500317

ABSTRACT

Recordings of event-related potentials (ERPs) were combined with structural and functional magnetic resonance imaging (fMRI) to investigate the timing and localization of stimulus selection processes during visual-spatial attention to pattern-reversing gratings. Pattern reversals were presented in random order to the left and right visual fields at a rapid rate, while subjects attended to the reversals in one field at a time. On separate runs, stimuli were presented in the upper and lower visual quadrants. The earliest ERP component (C1, peaking at around 80 ms), which inverted in polarity for upper versus lower field stimuli and was localized in or near visual area V1, was not modulated by attention. In the latency range 80-250 ms, multiple components were elicited that were increased in amplitude by attention and were colocalized with fMRI activations in specific visual cortical areas. The principal anatomical sources of these attention-sensitive components were localized by fMRI-seeded dipole modeling as follows: P1 (ca. 100 ms-source in motion-sensitive area MT+), C2 (ca. 130 ms-same source as C1), N1a (ca. 145 ms-source in horizontal intraparietal sulcus), N1b (ca. 165 ms-source in fusiform gyrus, area V4/V8), N1c (ca. 180 ms-source in posterior intraparietal sulcus, area V3A), and P2 (ca. 220 ms-multiple sources, including parieto-occipital sulcus, area V6). These results support the hypothesis that spatial attention acts to amplify both feed-forward and feedback signals in multiple visual areas of both the dorsal and ventral streams of processing.


Subject(s)
Attention/physiology , Cerebral Cortex/physiology , Evoked Potentials, Visual/physiology , Space Perception/physiology , Adolescent , Adult , Brain Mapping , Electroencephalography , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Reaction Time/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...