Conceptual representation of actions in sign language.
(2011)
Journal - Journal of deaf studies and deaf education (United States )
Abstract :
The idea that knowledge of events entails a universal spatial component, that is conceiving agents left of patients, was put to test by investigating native users of German sign language and native users of spoken German. Participants heard or saw event descriptions and had to illustrate the meaning of these events by means of drawing or arranging toys. Two types of verbs were tested, differing in the way they are signed. Verbs with a horizontal transient are typically signed with a left-to-right directionality, from the addressee's point of view. In contrast, verbs with sagittal transients display transitions moving toward or away from speaker. Signers showed a direct mapping preference for verbs with horizontal transients, by putting agents at the same position in space as in the signed message (i.e., mirroring signing space). No such effect was found for verbs with sagittal transients. In all, the data fit with the idea that interpretations of signed or spoken languages are modulated by task and culture as well as language-related factors and constraints.© The Author 2011. Published by Oxford University Press. All rights reserved.
| ISSN : | 1465-7325 |
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| Mesh Heading : | Adolescent Adult Art Child Culture Female Humans Language Male Middle Aged Play and Playthings Speech Young Adult |
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| Mesh Heading Relevant : | Concept Formation Sign Language |
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The role of gamma-band activity in the representation of faces: reduced activity in the fusiform face area in congenital prosopagnosia.
(2011)
Journal - PloS one (United States )
Abstract :
Congenital prosopagnosia (CP) describes an impairment in face processing that is presumably present from birth. The neuronal correlates of this dysfunction are still under debate. In the current paper, we investigate high-frequent oscillatory activity in response to faces in persons with CP. Such neuronal activity is thought to reflect higher-level representations for faces.Source localization of induced Gamma-Band Responses (iGBR) measured by magnetoencephalography (MEG) was used to establish the origin of oscillatory activity in response to famous and unknown faces which were presented in upright and inverted orientation. Persons suffering from congenital prosopagnosia (CP) were compared to matched controls.Corroborating earlier research, both groups revealed amplified iGBR in response to upright compared to inverted faces predominately in a time interval between 170 and 330 ms and in a frequency range from 50-100 Hz. Oscillatory activity upon known faces was smaller in comparison to unknown faces, suggesting a "sharpening" effect reflecting more efficient processing for familiar stimuli. These effects were seen in a wide cortical network encompassing temporal and parietal areas involved in the disambiguation of homogenous stimuli such as faces, and in the retrieval of semantic information. Importantly, participants suffering from CP displayed a strongly reduced iGBR in the left fusiform area compared to control participants.In sum, these data stress the crucial role of oscillatory activity for face representation and demonstrate the involvement of a distributed occipito-temporo-parietal network in generating iGBR. This study also provides the first evidence that persons suffering from an agnosia actually display reduced gamma band activity. Finally, the results argue strongly against the view that oscillatory activity is a mere epiphenomenon brought fourth by rapid eye-movements (micro saccades).
| ISSN : | 1932-6203 |
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| Mesh Heading : | Face Humans Neuropsychological Tests Photic Stimulation Prosopagnosia congenital physiopathology |
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| Mesh Heading Relevant : | Magnetoencephalography Recognition (Psychology) physiopathology |
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On the interplay between familiarity and emotional expression in face perception.
(2008)
Journal - Psychological research (Germany )
Abstract :
Traditional models of face perception (e.g. Bruce and Young 1986) stress independent routes for processing identity and emotional expression. We investigated the interplay between familiarity and emotional expression by systematically varying both factors. In contrast to earlier studies which used binary forced-choice decisions, participants had to judge the familiarity of the presented face and the emotional hedonic valence and emotional arousal of its expressed emotion (angry, happy or neutral), using rating scales. The results demonstrated symmetric, strong interactions between familiarity and expressed emotion. Thus, this study supports more recent models of face perception (Haxby et al. 2000) that were mostly based on brain imaging data. These data together with our behavioural results emphasize the interaction of emotional expression and personal identity and support approaches that propose a relative segregation of these processes, rather than completely independent coding (Calder and Young 2005).
| ISSN : | 0340-0727 |
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| Mesh Heading : | Adult Female Humans Male |
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| Mesh Heading Relevant : | Affect Facial Expression Recognition (Psychology) Visual Perception |
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Early left-hemispheric dysfunction of face processing in congenital prosopagnosia: an MEG study.
(2008)
Journal - PLoS ONE (United States )
Abstract :
BACKGROUND: Congenital prosopagnosia is a severe face perception impairment which is not acquired by a brain lesion and is presumably present from birth. It manifests mostly by an inability to recognise familiar persons. Electrophysiological research has demonstrated the relevance to face processing of a negative deflection peaking around 170 ms, labelled accordingly as N170 in the electroencephalogram (EEG) and M170 in magnetoencephalography (MEG). The M170 was shown to be sensitive to the inversion of faces and to familiarity--two factors that are assumed to be crucial for congenital prosopagnosia. In order to locate the cognitive dysfunction and its neural correlates, we investigated the time course of neural activity in response to these manipulations. METHODOLOGY: Seven individuals with congenital prosopagnosia and seven matched controls participated in the experiment. To explore brain activity with high accuracy in time, we recorded evoked magnetic fields (275 channel whole head MEG) while participants were looking at faces differing in familiarity (famous vs. unknown) and orientation (upright vs. inverted). The underlying neural sources were estimated by means of the least square minimum-norm-estimation (L2-MNE) approach. PRINCIPAL FINDINGS: The behavioural data corroborate earlier findings on impaired configural processing in congenital prosopagnosia. For the M170, the overall results replicated earlier findings, with larger occipito-temporal brain responses to inverted than upright faces, and more right- than left-hemispheric activity. Compared to controls, participants with congenital prosopagnosia displayed a general decrease in brain activity, primarily over left occipitotemporal areas. This attenuation did not interact with familiarity or orientation. CONCLUSIONS: The study substantiates the finding of an early involvement of the left hemisphere in symptoms of prosopagnosia. This might be related to an efficient and overused featural processing strategy which serves as a compensation of impaired configural processing.
| ISSN : | 1932-6203 |
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| Mesh Heading : | Adult Case-Control Studies Cerebrum Female Humans Magnetoencephalography Male Middle Aged Photic Stimulation Prosopagnosia Questionnaires congenital |
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| Mesh Heading Relevant : | physiopathology physiopathology |
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Describing scenes hardly seen.
(2007)
Journal - Acta psychologica (Netherlands )
Abstract :
Knowledge about scene categories, the so-called gist, can be extracted very rapidly, while recognition and naming of individual scene objects is a more effortful process. We investigate this phenomenon by presenting action scenes involving two actors for durations varying between 100 and 300 ms. Incoherence was created by mirroring individual scene actors. Upon masked presentation participants had to report content, actors and objects and to indicate whether the scene was meaningful or not. Scene coherence was judged correctly at all presentation durations. Actors were correctly identified in about one-third of the cases even with presentation durations of 100 ms, and identification rate increased up to 80% with longer durations. Identification depended on scene coherence, on the position of agents in the scene, and on the position of actors relative to the fixation cross. These interdependencies of scene and object perception indicate that the visual system seems to be very sensitive to meaningful interactions of living entities. A series of fixations is not necessary to identify actors of a scene.
| ISSN : | 0001-6918 |
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| Mesh Heading : | Attention Cognition Discrimination Learning Humans Judgment Mental Recall Orientation Pattern Recognition, Visual Perceptual Masking Photic Stimulation Recognition (Psychology) Students Time Factors physiology physiology physiology physiology physiology physiology methods psychology |
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| Mesh Heading Relevant : | physiology physiology physiology |
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How writing system and age influence spatial representations of actions: a developmental, cross-linguistic study.
(2007)
Journal - Psychological science : a journal of the American Psychological Society / APS (United States )
Abstract :
Recently, researchers reported a bias for placing agents predominantly on the left side of pictures. Both hemispheric specialization and cultural preferences have been hypothesized to be the origin of this bias. To evaluate these hypotheses, we conducted a study with participants exposed to different reading and writing systems: Germans, who use a left-to-right system, and Israelis, who use a right-to-left system. In addition, we manipulated the degree of exposure to the writing systems by testing preschoolers and adults. Participants heard agent-first or recipient-first sentences and were asked to draw the content of the sentences or to arrange transparencies of protagonists and objects such that their arrangement depicted the sentences. Although preschool-age children in both countries showed no directional bias, adults manifested a bias that was consistent with the writing system of their language. These results support the cultural hypothesis regarding the origin of spatial-representational biases.
| ISSN : | 0956-7976 |
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| Mesh Heading : | Adult Age Factors Child Child Development Child, Preschool Dominance, Cerebral Female Germany Humans Israel Linguistics Male Reading Space Perception physiology |
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| Mesh Heading Relevant : | Cross-Cultural Comparison Writing physiology methods physiology |
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Early Left-Hemispheric Dysfunction of Face Processing in Congenital Prosopagnosia: An MEG Study
(2008)
Journal - PLoS ONE
Abstract :
BackgroundCongenital prosopagnosia is a severe face perception impairment which is not acquired by a brain lesion and is presumably present from birth. It manifests mostly by an inability to recognise familiar persons.Electrophysiological research has demonstrated the relevance to face processing of a negative deflection peaking around 170 ms, labelled accordingly as N170 in the electroencephalogram (EEG) and M170 in magnetoencephalography (MEG). The M170 was shown to be sensitive to the inversion of faces and to familiarity-two factors that are assumed to be crucial for congenital prosopagnosia. In order to locate the cognitive dysfunction and its neural correlates, we investigated the time course of neural activity in response to these manipulations.MethodologySeven individuals with congenital prosopagnosia and seven matched controls participated in the experiment. To explore brain activity with high accuracy in time, we recorded evoked magnetic fields (275 channel whole head MEG) while participants were looking at faces differing in familiarity (famous vs. unknown) and orientation (upright vs. inverted). The underlying neural sources were estimated by means of the least square minimum-norm-estimation (L2-MNE) approach.Principal FindingsThe behavioural data corroborate earlier findings on impaired configural processing in congenital prosopagnosia. For the M170, the overall results replicated earlier findings, with larger occipito-temporal brain responses to inverted than upright faces, and more right- than left-hemispheric activity. Compared to controls, participants with congenital prosopagnosia displayed a general decrease in brain activity, primarily over left occipitotemporal areas. This attenuation did not interact with familiarity or orientation.ConclusionsThe study substantiates the finding of an early involvement of the left hemisphere in symptoms of prosopagnosia. This might be related to an efficient and overused featural processing strategy which serves as a compensation of impaired configural processing.