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1.
J Exp Psychol Hum Percept Perform ; 47(8): 1043-1055, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34516211

RESUMO

It is widely believed that the emotional and movtivational value of social signals, such as faces, influences perception and attention. However, effects reported for stimuli with intrinsic affective value, such as emotional facial expressions, can often be explained by differences in low-level stimulus properties. To rule out such low-level effects, here we used a value-learning procedure, in which faces were associated with different probabilities of monetary gain and loss in a choice game. In three experiments involving 149 participants, we tested the influence of affective valence (win- vs. loss-associated faces) and motivational salience (probability of monetary gain or loss) on visual awareness, attention, and memory. Using continuous flash suppression and rapid serial visual presentation, we found no effects of affective valence or motivational salience on visual awareness of faces. Furthermore, in two experiments, there was no evidence for a modulation of the attentional blink, indicating that acquired emotional and motivational value does not influence attentional priority of faces. However, we found that motivational salience boosted recognition memory, and this effect was particularly pronounced for win-associated faces. These results indicate that acquired affective valence and motivational salience affect only later processing of faces related to memory but do not directly affect visual awareness and attention. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

2.
PLoS Biol ; 19(5): e3001241, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33951043

RESUMO

The study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant's report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness and may influence conclusions about the extent of unconscious processing and about the neural correlates of consciousness. We obtained functional magnetic resonance imaging (fMRI) measurements from 43 subjects while they viewed masked faces and houses that were either subjectively or objectively invisible. Even for objectively invisible (perceptually indiscriminable) stimuli, we found significant category information in both early, lower-level visual areas and in higher-level visual cortex, although representations in anterior, category-selective ventrotemporal areas were less robust. For subjectively invisible stimuli, similar to visible stimuli, there was a clear posterior-to-anterior gradient in visual cortex, with stronger category information in ventrotemporal cortex than in early visual cortex. For objectively invisible stimuli, however, category information remained virtually unchanged from early visual cortex to object- and category-selective visual areas. These results demonstrate that although both objectively and subjectively invisible stimuli are represented in visual cortex, the extent of unconscious information processing is influenced by the measurement approach. Furthermore, our data show that subjective and objective approaches are associated with different neural correlates of consciousness and thus have implications for neural theories of consciousness.


Assuntos
Conscientização/fisiologia , Visão Ocular/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Estado de Consciência/fisiologia , Feminino , Substância Cinzenta/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Córtex Visual/fisiologia , Adulto Jovem
3.
Nat Hum Behav ; 5(5): 612-624, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33398144

RESUMO

The scope of unconscious processing is highly debated, with recent studies showing that even high-level functions such as perceptual integration and category-based attention occur unconsciously. For example, upright faces that are suppressed from awareness through interocular suppression break into awareness more quickly than inverted faces. Similarly, verbal object cues boost otherwise invisible objects into awareness. Here, we replicate these findings, but find that they reflect a general difference in detectability not specific to interocular suppression. To dissociate conscious and unconscious influences on visual detection effects, we use an additional discrimination task to rule out conscious processes as a cause for these differences. Results from this detection-discrimination dissociation paradigm reveal that, while face orientation is processed unconsciously, category-based attention requires awareness. These findings provide insights into the function of conscious perception and offer an experimental approach for mapping out the scope and limits of unconscious processing.


Assuntos
Atenção/fisiologia , Conscientização/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
4.
Cogn Neurosci ; 12(2): 97-98, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33176561

RESUMO

In their paper Doerig et al. argue that we should put the hard problem aside and focus on empirical data to solve the 'easy' problems of consciousness - finding the neural and functional correlates of consciousness. In other words 'shut up and measure'. This has worked well with other thorny issues, such as explaining life, so why not adopt this approach here? We argue that despite the popularity of this view it is not feasible. In order to collect any consciousness data one needs to take an implicit or explicit stance on the hard problem.

5.
Emotion ; 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32202850

RESUMO

Past research has found an attentional bias for positive relative to neutral stimuli, with a greater attentional bias for stimuli that are more motivationally relevant. Baby faces are an example of a motivationally relevant stimulus because they elicit caretaking behaviors. Building on previous work demonstrating that baby faces capture attention, the current study used breaking continuous flash suppression (bCFS) to investigate whether infant faces are prioritized for access to awareness. On each trial of the task, a face was shown to one eye and a rapidly changing Mondrian pattern to the other. Participants were asked to report the location of the face as soon as it emerged from suppression. The faces were either infant or adult faces, presented in upright or inverted orientation. Despite evidence suggesting that infant faces might reach awareness more quickly than adult faces, the opposite was found: Adult faces reached awareness more quickly than infant faces. Moreover, a stronger face inversion effect was observed for adult versus infant faces, indicating that the shorter suppression times for adult faces were due to increased expertise with adult faces. A past bCFS study demonstrated an own-age face effect for young adults, but it left open the possibility that this effect was due to the youthful appearance of the young versus old faces. The current results rule out this possibility and provide further support for the idea that experience with faces of one's own social group facilitates the access of those faces to awareness. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

6.
Conscious Cogn ; 78: 102864, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896031

RESUMO

It is debated whether the meaning of invisible pictures can be processed unconsciously. We tested whether pictures of animals or objects presented under backward masking or continuous flash suppression could prime the subsequent categorization of target words into animal or non-animal. In Experiment 1, the backward masking part failed to replicate the priming effect reported in two previous studies, despite sufficient statistical power (N = 59). Similarly, the continuous flash suppression part provided no evidence for a priming effect. In Experiment 2 (N = 65) we shortened the prime-target SOA from 290 ms to 90 ms, but again failed to obtain unconscious semantic priming under backward masking. Thus, our study did not provide evidence for unconscious semantic processing of pictures. These findings support the emerging view that unconscious processing is rather limited in scope.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Leitura , Inconsciente Psicológico , Adulto , Associação , Humanos , Desempenho Psicomotor/fisiologia , Semântica , Adulto Jovem
7.
Schizophr Res Cogn ; 19: 100165, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31832345

RESUMO

Research on visual perception in schizophrenia suggests a deficit in motion processing. Specifically, difficulties with discriminating motion speed are commonly reported. However, speed discrimination tasks typically require participants to make judgments about the difference between two stimuli in a two-interval forced choice (2IFC) task. Such tasks not only tap into speed processing mechanisms, but also rely on higher executive functioning including working memory and attention which has been shown to be compromised in schizophrenia. We used the Flash Lag illusion to examine speed processing in patients with schizophrenia. Based on previous research showing a strong dependence between motion speed and the illusion magnitude, we expected a deficit in speed processing to alter this relationship. A motion processing deficit in patients would also predict overall reductions in perceived lag. We found the magnitude and speed dependence of the Flash Lag illusion to be similar in patients and controls. Together, the findings suggest no general abnormality in motion speed processing in schizophrenia.

8.
Dalton Trans ; 48(40): 15127-15135, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31560355

RESUMO

Four metal-organic frameworks employing the m-terphenyl diisophthalate linker molecule with 2' substitution by P(v)-based functional groups of the central aryl have been synthesised. The dense packing of POMe2/PSMe2 functional groups within UHM-60/UHM-61 (UHM: University of Hamburg Materials) with an underlying net of ucp topology was overcome by increasing the sterical demand of phosphorus substituents. Replacement of the PEMe2 (E = O, S) functional groups by POEt2 or POPh2 gave UHM-62 and UHM-63, respectively, where valid deconstructions of the underlying topology to types 3,3,4,4T199, tim, and tst were found. The potential influence of the now-accessible phosphoryl functional group towards CO2 and CH4 adsorption as well as the selectivity towards CO2/CH4 separation was studied. Based on a comprehensive survey of literature-known Cu(ii)-based MOFs with m-terphenyl-based linker molecules, we propose the deconstruction of inter-isophthalate plane angles to angular components of twist and fold allowing for the sophisticated classification of topologies that can be realised in Cu(ii)-based MOFs using the m-terphenyl tetracarboxylate linker molecule.

9.
Cogn Neuropsychiatry ; 24(2): 135-151, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30848987

RESUMO

INTRODUCTION: Faces provide a rich source of social information, crucial for the successful navigation of daily social interactions. People with schizophrenia suffer a wide range of social-cognitive deficits, including abnormalities in face perception. However, to date, studies of face perception in schizophrenia have primarily employed tasks that require patients to make judgements about the faces. It is, thus, unclear whether the reported deficits reflect an impairment in encoding visual face information, or biased social-cognitive evaluative processes. METHODS: We assess the integrity of early unconscious face processing in 21 out-patients diagnosed with Schizophrenia or Schizoaffective Disorder (15M/6F) and 21 healthy controls (14M/7F). In order to control for any direct influence of higher order cognitive processes, we use a behavioural paradigm known as breaking continuous flash suppression (b-CFS), where participants simply respond to the presence and location of a face. In healthy adults, this method has previously been used to show that upright faces gain rapid and privileged access to conscious awareness over inverted faces and other inanimate objects. RESULTS: Here, we report similar effects in patients, suggesting that the early unconscious stages of face processing are intact in schizophrenia. CONCLUSION: Our data indicate that face processing deficits reported in the literature must manifest at a conscious stage of processing, where the influence of mentalizing or attribution biases might play a role.


Assuntos
Estado de Consciência/fisiologia , Reconhecimento Facial/fisiologia , Estimulação Luminosa/métodos , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Percepção Social , Adulto , Conscientização/fisiologia , Feminino , Humanos , Julgamento/fisiologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Emotion ; 19(5): 928-932, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30762381

RESUMO

Using breaking continuous flash suppression (b-CFS; a perceptual suppression technique), Gomes, Soares, Silva, and Silva (2018) showed that human observers have an advantage in detecting images of snakes (constituting an evolutionarily old threat) over birds. In their study, images of snakes and birds were filtered to contain either coarse-scale or fine-grained information. The preferential detection of snakes relied on coarse-scale (rather than fine-grained) information, which was taken as support for the existence of an evolutionarily old subcortical pathway dedicated to snake detection. Here, we raise the concern that images of snakes and birds inherently differ in their visual characteristics, which can strongly affect detection times in b-CFS. Images of snakes, for instance, have a larger perimeter-to-surface ratio than images of birds. Importantly, these visual characteristics are not snake specific, as they are shared with many nonthreatening object categories. To illustrate this point, we compared detection times between images of bicycles and cars-nonthreatening image categories that differ in visual characteristics but for which detection is unlikely to capitalize on an evolutionarily old dedicated subcortical pathway. Observers exhibited an advantage for detecting bicycles over cars. Mirroring the snake-bird differences reported in Gomes et al., this advantage was driven by the coarse-scale (rather than fine-grained) information in the images. Hence, differences in visual characteristics between two nonthreatening, semantically matched stimulus categories suffice to produce the exact same pattern of findings as observed with snakes versus birds. We conclude that spatial frequency-specific detection differences in b-CFS cannot be unequivocally attributed to differences in processing pathways. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Aves , Medo , Animais , Humanos
12.
Schizophr Res ; 210: 245-254, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30587425

RESUMO

The predictive coding account of psychosis postulates the abnormal formation of prior beliefs in schizophrenia, resulting in psychotic symptoms. One domain in which priors play a crucial role is visual perception. For instance, our perception of brightness, line length, and motion direction are not merely based on a veridical extraction of sensory input but are also determined by expectation (or prior) of the stimulus. Formation of such priors is thought to be governed by the statistical regularities within natural scenes. Recently, the use of such priors has been attributed to a specific set of well-documented visual illusions, supporting the idea that perception is biased toward what is statistically more probable within the environment. The Predictive Coding account of psychosis proposes that patients form abnormal representations of statistical regularities in natural scenes, leading to altered perceptual experiences. Here we use classical vision experiments involving a specific set of visual illusions to directly test this hypothesis. We find that perceptual judgments for both patients and control participants are biased in accordance with reported probability distributions of natural scenes. Thus, despite there being a suggested link between visual abnormalities and psychotic symptoms in schizophrenia, our results provide no support for the notion that altered formation of priors is a general feature of the disorder. These data call for a refinement in the predictions of quantitative models of psychosis.


Assuntos
Ilusões/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Feminino , Humanos , Ilusões/etiologia , Masculino , Probabilidade , Transtornos Psicóticos/complicações , Esquizofrenia/complicações , Distribuições Estatísticas , Adulto Jovem
13.
J Vis ; 18(11): 3, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30326050

RESUMO

Neural responses to visual stimuli are modulated by spatial and temporal context. For example, in primary visual cortex (V1), responses to an oriented target stimulus will be suppressed when embedded within an oriented surround stimulus. This suppression is orientation-specific, with the largest suppression observed when stimuli in the neuron's classical receptive field and surround are of similar orientation. In human psychological experiments, the tilt illusion and tilt aftereffect demonstrate an effect of context on perceived orientation of a target stimulus. Similar to the neurophysiological data, the strength of these effects is modulated by the orientation difference between the target stimulus and context. It has been hypothesized that the neural mechanism underlying both the tilt illusion and tilt aftereffect involves orientation-tuned inhibition in V1. However, to date there is no direct evidence linking human perception of these illusions with measurements of inhibition from human visual cortex. Here, we measured context-induced suppression of neural responses in human visual cortex using functional magnetic resonance imaging (fMRI). In the same participants, we also measured magnitudes of their tilt illusion and tilt aftereffect. Our data revealed a significant relationship between the magnitude of neural suppression in V1 and size of the tilt illusion and tilt aftereffect. That is, participants who showed stronger blood oxygenation level dependent (BOLD) suppression in V1 also perceived stronger shifts in illusory tilt. This agreement between perception and neural responses in human V1 suggests a shared inhibitory mechanism that mediates both spatial and temporal effects of context in human perception.


Assuntos
Pós-Imagem/fisiologia , Ilusões/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Inibição Psicológica , Imageamento por Ressonância Magnética , Masculino , Orientação/fisiologia , Estimulação Luminosa/métodos , Adulto Jovem
14.
J Exp Psychol Gen ; 147(11): e1-e13, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30372110

RESUMO

Visual stimuli with social-emotional relevance have been claimed to gain preferential access to awareness. For example, recent studies used the breaking continuous flash suppression paradigm (b-CFS) to show that faces that are perceived as less dominant and more trustworthy are prioritized for awareness. Here we asked whether these effects truly reflect differences in social-emotional meaning or whether they can be equally explained by differences in low-level stimulus properties. In Experiment 1, we successfully replicated dominance- and untrustworthiness-related slowing for upright faces. However, these effects were equally strong for inverted faces, even though it was more difficult to perceive social characteristics in inverted faces. The previously reported correlation between dominance- and untrustworthiness-related slowing in b-CFS and self-reported propensity to trust did not replicate. Experiment 2 showed that dominance-related slowing in b-CFS can also be observed when only presenting the eye region of faces, and even when the eye region was presented inverted and/or with reversed contrast polarity, in which case personality traits were no longer discernible. These results were replicated in Experiment 3 following a preregistration protocol. Altogether, our findings link dominance-related slowing in b-CFS to physical differences in the eye region that are-when presented in isolation-unrelated to the perception of dominance. We conclude that low-level physical stimulus differences provide a parsimonious explanation for the effect of social facial characteristics on access to awareness. (PsycINFO Database Record (c) 2018 APA, all rights reserved).


Assuntos
Conscientização , Expressão Facial , Processos Mentais , Confiança/psicologia , Inconsciente Psicológico , Adulto , Emoções , Feminino , Humanos , Masculino , Adulto Jovem
15.
Cognition ; 168: 129-139, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28672158

RESUMO

Biological motion (BM) is one of the most important social cues for detecting conspecifics, prey, and predators. We show that unconscious BM processing can reflexively direct spatial attention, and that this effect has a biphasic temporal profile. Participants responded to probes that were preceded by intact or scrambled BM cues rendered invisible through continuous flash suppression. With a short inter-stimulus interval (ISI, 100ms) between the invisible BM cues and the probe, responses to probes at the same location as the invisible, nonpredictive BM cue were faster than to probes at the location of the scrambled BM cue. With a longer ISI (800ms) this effect reversed, with slower responses to probes at the location of the invisible, nonpredictive BM. These effects were absent when BM and its scrambled control were made visible with both short and long cue durations across variable length of ISIs, indicating that the saliency of BM itself cannot account for the dynamic orienting effects from invisible social cues. Moreover, this dynamic attentional shifts were specific to upright BM cues and not obtained for inverted stimuli. Thus, this reflexive and dynamic attentional modulation triggered by invisible BM, with initial facilitation followed by inhibition, demonstrates that in the complete absence of conscious awareness, cue predictiveness, and saliency differences, attentional systems promote exploration of our visual environment for social signals.


Assuntos
Atenção , Percepção de Movimento , Adolescente , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Mascaramento Perceptivo , Estimulação Luminosa , Adulto Jovem
16.
Emotion ; 17(8): 1199-1207, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28406677

RESUMO

Stimuli with intrinsic emotional value, like emotional faces, and stimuli associated with reward and punishment are often prioritized in visual awareness relative to neutral stimuli. Recently, Anderson, Siegel, Bliss-Moreau, and Barrett (2011) demonstrated that simply associating a face with affective knowledge can also influence visual awareness. Using a binocular rivalry task (BR), where a face was shown to one eye and a house to the other, they found that faces paired with negative versus neutral and positive behaviors dominated visual awareness. We were interested in whether faces associated with negative information would also be capable of reaching awareness more quickly in the first place. To test this, we set out to replicate Anderson and colleagues' finding and to examine whether it would extend to breaking continuous flash suppression (b-CFS), a technique where a dynamic mask shown to one eye initially suppresses the stimulus shown to the other eye. Participants completed a learning task followed by BR and b-CFS tasks, in counterbalanced order. Across both tasks, faces associated with negative behaviors were treated no differently from faces associated with neutral or positive behaviors. However, faces associated with any type of behavior were prioritized in awareness over novel faces. These findings indicate that while familiarity influences conscious perception, the influence of affective person knowledge on visual awareness is more circumscribed than previously thought. (PsycINFO Database Record


Assuntos
Afeto , Conscientização , Reconhecimento Facial , Reconhecimento Psicológico , Visão Binocular/fisiologia , Adolescente , Face , Feminino , Habitação , Humanos , Aprendizagem , Masculino , Adulto Jovem
17.
Front Psychol ; 8: 437, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28396645

RESUMO

A recent focus in the field of consciousness research involves investigating the propensity of initially non-conscious visual information to gain access to consciousness. A critical tool for measuring conscious access is the so-called breaking continuous flash suppression paradigm (b-CFS). In this paradigm, a high contrast dynamic pattern is presented to one eye, thereby temporarily suppressing a target stimulus that is presented to the other eye. The time it takes for observers to report (e.g., the location of) the initially suppressed stimulus provides a measure of conscious access. Typical observations in b-CFS studies include the finding that upright faces are released from suppression faster than inverted faces, and the finding that stimuli that match the current content of visual working memory are released from suppression faster than mismatching stimuli. Interestingly, the extent to which observers exhibit these effects varies extensively (in the range of hundreds of milliseconds). By re-analyzing existing datasets and a new dataset we establish that the difference in RTs between conditions in b-CFS tasks (i.e., the effect of interest) is highly correlated with participants' overall suppression durations, and with their trial-to-trial variability in RTs. We advocate the usage of a simple latency- normalization method, which (1) removes the between-subject variability in suppression duration from the effect of interest, while (2) providing distributions of RT differences that are better suited for parametric testing. We next compare this latency-normalization method to two other transformations that are widely applied on within-subject RT data (z-transformations and log-transformations). Finally, we tentatively discuss how trial-to-trial variability and overall suppression duration might relate to prolonged phases of shallow suppression that are more prone to modulations of conscious access.

18.
Ann N Y Acad Sci ; 1396(1): 92-107, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28253445

RESUMO

Top-down attention is the mechanism that allows us to selectively process goal-relevant aspects of a scene while ignoring irrelevant aspects. A large body of research has characterized the effects of attention on neural activity evoked by a visual stimulus. However, attention also includes a preparatory phase before stimulus onset in which the attended dimension is internally represented. Here, we review neurophysiological, functional magnetic resonance imaging, magnetoencephalography, electroencephalography, and transcranial magnetic stimulation (TMS) studies investigating the neural basis of preparatory attention, both when attention is directed to a location in space and when it is directed to nonspatial stimulus attributes (content-based attention) ranging from low-level features to object categories. Results show that both spatial and content-based attention lead to increased baseline activity in neural populations that selectively code for the attended attribute. TMS studies provide evidence that this preparatory activity is causally related to subsequent attentional selection and behavioral performance. Attention thus acts by preactivating selective neurons in the visual cortex before stimulus onset. This appears to be a general mechanism that can operate on multiple levels of representation. We discuss the functional relevance of this mechanism, its limitations, and its relation to working memory, imagery, and expectation. We conclude by outlining open questions and future directions.


Assuntos
Atenção/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual/diagnóstico por imagem , Mapeamento Encefálico , Eletroencefalografia/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Magnetoencefalografia/métodos , Estimulação Luminosa , Estimulação Magnética Transcraniana/métodos , Córtex Visual/fisiologia
19.
Atten Percept Psychophys ; 79(3): 738-752, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28138945

RESUMO

Humans are remarkably efficient in detecting highly familiar object categories in natural scenes, with evidence suggesting that such object detection can be performed in the (near) absence of attention. Here we systematically explored the influences of both spatial attention and category-based attention on the accuracy of object detection in natural scenes. Manipulating both types of attention additionally allowed for addressing how these factors interact: whether the requirement for spatial attention depends on the extent to which observers are prepared to detect a specific object category-that is, on category-based attention. The results showed that the detection of targets from one category (animals or vehicles) was better than the detection of targets from two categories (animals and vehicles), demonstrating the beneficial effect of category-based attention. This effect did not depend on the semantic congruency of the target object and the background scene, indicating that observers attended to visual features diagnostic of the foreground target objects from the cued category. Importantly, in three experiments the detection of objects in scenes presented in the periphery was significantly impaired when observers simultaneously performed an attentionally demanding task at fixation, showing that spatial attention affects natural scene perception. In all experiments, the effects of category-based attention and spatial attention on object detection performance were additive rather than interactive. Finally, neither spatial nor category-based attention influenced metacognitive ability for object detection performance. These findings demonstrate that efficient object detection in natural scenes is independently facilitated by spatial and category-based attention.


Assuntos
Atenção/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Espacial/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
20.
Psychol Sci ; 28(3): 369-379, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28140764

RESUMO

How does one perceive groups of people? It is known that functionally interacting objects (e.g., a glass and a pitcher tilted as if pouring water into it) are perceptually grouped. Here, we showed that processing of multiple human bodies is also influenced by their relative positioning. In a series of categorization experiments, bodies facing each other (seemingly interacting) were recognized more accurately than bodies facing away from each other (noninteracting). Moreover, recognition of facing body dyads (but not nonfacing body dyads) was strongly impaired when those stimuli were inverted, similar to what has been found for individual bodies. This inversion effect demonstrates sensitivity of the visual system to facing body dyads in their common upright configuration and might imply recruitment of configural processing (i.e., processing of the overall body configuration without prior part-by-part analysis). These findings suggest that facing dyads are represented as one structured unit, which may be the intermediate level of representation between multiple-object (body) perception and representation of social actions.


Assuntos
Corpo Humano , Reconhecimento Visual de Modelos/fisiologia , Percepção Social , Adolescente , Adulto , Humanos , Adulto Jovem
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