scholarly journals Functional Context Affects Scene Processing

2021 ◽  
pp. 1-13
Author(s):  
Elissa M. Aminoff ◽  
Michael J. Tarr

Abstract Rapid visual perception is often viewed as a bottom–up process. Category-preferred neural regions are often characterized as automatic, default processing mechanisms for visual inputs of their categorical preference. To explore the sensitivity of such regions to top–down information, we examined three scene-preferring brain regions, the occipital place area (OPA), the parahippocampal place area (PPA), and the retrosplenial complex (RSC), and tested whether the processing of outdoor scenes is influenced by the functional contexts in which they are seen. Context was manipulated by presenting real-world landscape images as if being viewed through a window or within a picture frame—manipulations that do not affect scene content but do affect one's functional knowledge regarding the scene. This manipulation influences neural scene processing (as measured by fMRI): The OPA and the PPA exhibited greater neural activity when participants viewed images as if through a window as compared with within a picture frame, whereas the RSC did not show this difference. In a separate behavioral experiment, functional context affected scene memory in predictable directions (boundary extension). Our interpretation is that the window context denotes three-dimensionality, therefore rendering the perceptual experience of viewing landscapes as more realistic. Conversely, the frame context denotes a 2-D image. As such, more spatially biased scene representations in the OPA and the PPA are influenced by differences in top–down, perceptual expectations generated from context. In contrast, more semantically biased scene representations in the RSC are likely to be less affected by top–down signals that carry information about the physical layout of a scene.

2020 ◽  
Author(s):  
Elissa M. Aminoff ◽  
Michael J. Tarr

AbstractRapid visual perception is often viewed as a bottom-up process. Category-preferred neural regions are often characterized as automatic, default processing mechanisms for visual inputs of their categorical preference. To explore the sensitivity of such regions to top-down information, we examined three scene-preferring brain regions, the occipital place area (OPA), the parahippocampal place area (PPA), and the retrosplenial complex (RSC), and tested whether the processing of outdoor scenes is influenced by the functional contexts in which they are seen. Context was manipulated by presenting real-world landscape images as if being viewed through a window or within a picture frame; manipulations that do not affect scene content but do affect one’s functional knowledge regarding the scene. This manipulation influences neural scene processing (as measured by fMRI): the OPA and PPA exhibited greater neural activity when participants viewed images as if through a window as compared to within a picture frame, while the RSC did not show this difference. In a separate behavioral experiment, functional context affected scene memory in predictable directions (boundary extension). Our interpretation is that the window context denotes three-dimensionality, therefore rendering the perceptual experience of viewing landscapes as more realistic. Conversely, the frame context denotes a two-dimensional image. As such, more spatially-biased scene representations in the OPA and the PPA are influenced by differences in top-down, perceptual expectations generated from context. In contrast, more semantically-biased scene representations in the RSC are likely to be less affected by top-down signals that carry information about the physical layout of a scene.


2017 ◽  
Vol 28 (7) ◽  
pp. 894-906 ◽  
Author(s):  
Adrianna C. Jenkins ◽  
Ming Hsu

The ability to exercise patience is important for human functioning. Although it is known that patience can be promoted by using top-down control, or willpower, to override impatient impulses, patience is also malleable—in particular, susceptible to framing effects—in ways that are difficult to explain using willpower alone. So far, the mechanisms underlying framing effects on patience have been elusive. We investigated the role of imagination in these effects. In a behavioral experiment (Experiment 1), a classic framing manipulation (sequence framing) increased self-reported and independently coded imagination during intertemporal choice. In an investigation of neural responses during decision making (Experiment 2), sequence framing increased the extent to which patience was related to activation in brain regions associated with imagination, relative to activation in regions associated with willpower, and increased functional connectivity of brain regions associated with imagination, but not willpower, relative to regions associated with valuation. Our results suggest that sequence framing can increase the role of imagination in decision making without increasing the exertion of willpower.


2014 ◽  
Vol 112 (6) ◽  
pp. 1307-1316 ◽  
Author(s):  
Isabel Dombrowe ◽  
Claus C. Hilgetag

The voluntary, top-down allocation of visual spatial attention has been linked to changes in the alpha-band of the electroencephalogram (EEG) signal measured over occipital and parietal lobes. In the present study, we investigated how occipitoparietal alpha-band activity changes when people allocate their attentional resources in a graded fashion across the visual field. We asked participants to either completely shift their attention into one hemifield, to balance their attention equally across the entire visual field, or to attribute more attention to one-half of the visual field than to the other. As expected, we found that alpha-band amplitudes decreased stronger contralaterally than ipsilaterally to the attended side when attention was shifted completely. Alpha-band amplitudes decreased bilaterally when attention was balanced equally across the visual field. However, when participants allocated more attentional resources to one-half of the visual field, this was not reflected in the alpha-band amplitudes, which just decreased bilaterally. We found that the performance of the participants was more strongly reflected in the coherence between frontal and occipitoparietal brain regions. We conclude that low alpha-band amplitudes seem to be necessary for stimulus detection. Furthermore, complete shifts of attention are directly reflected in the lateralization of alpha-band amplitudes. In the present study, a gradual allocation of visual attention across the visual field was only indirectly reflected in the alpha-band activity over occipital and parietal cortexes.


Author(s):  
Jochem van Kempen ◽  
Marc A. Gieselmann ◽  
Michael Boyd ◽  
Nicholas A. Steinmetz ◽  
Tirin Moore ◽  
...  

AbstractSpontaneous fluctuations in cortical excitability influence sensory processing and behavior. These fluctuations, long known to reflect global changes in cortical state, were recently found to be modulated locally within a retinotopic map during spatially selective attention. We found that periods of vigorous (On) and faint (Off) spiking activity, the signature of cortical state fluctuations, were coordinated across brain areas along the visual hierarchy and tightly coupled to their retinotopic alignment. During top-down attention, this interareal coordination was enhanced and progressed along the reverse cortical hierarchy. The extent of local state coordination between areas was predictive of behavioral performance. Our results show that cortical state dynamics are shared across brain regions, modulated by cognitive demands and relevant for behavior.One Sentence SummaryInterareal coordination of local cortical state is retinotopically precise and progresses in a reverse hierarchical manner during selective attention.


2019 ◽  
Vol 30 (3) ◽  
pp. 875-887
Author(s):  
Kai Hwang ◽  
James M Shine ◽  
Dillan Cellier ◽  
Mark D’Esposito

Abstract Past studies have demonstrated that flexible interactions between brain regions support a wide range of goal-directed behaviors. However, the neural mechanisms that underlie adaptive communication between brain regions are not well understood. In this study, we combined theta-burst transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging to investigate the sources of top-down biasing signals that influence task-evoked functional connectivity. Subjects viewed sequences of images of faces and buildings and were required to detect repetitions (2-back vs. 1-back) of the attended stimuli category (faces or buildings). We found that functional connectivity between ventral temporal cortex and the primary visual cortex (VC) increased during processing of task-relevant stimuli, especially during higher memory loads. Furthermore, the strength of functional connectivity was greater for correct trials. Increases in task-evoked functional connectivity strength were correlated with increases in activity in multiple frontal, parietal, and subcortical (caudate and thalamus) regions. Finally, we found that TMS to superior intraparietal sulcus (IPS), but not to primary somatosensory cortex, decreased task-specific modulation in connectivity patterns between the primary VC and the parahippocampal place area. These findings demonstrate that the human IPS is a source of top-down biasing signals that modulate task-evoked functional connectivity among task-relevant cortical regions.


Author(s):  
David J. Madden ◽  
Zachary A. Monge

Age-related decline occurs in several aspects of fluid, speed-dependent cognition, particularly those related to attention. Empirical research on visual attention has determined that attention-related effects occur across a range of information processing components, including the sensory registration of features, selection of information from working memory, controlling motor responses, and coordinating multiple perceptual and cognitive tasks. Thus, attention is a multifaceted construct that is relevant at virtually all stages of object identification. A fundamental theme of attentional functioning is the interaction between the bottom-up salience of visual features and top-down allocation of processing based on the observer’s goals. An underlying age-related slowing is prominent throughout visual processing stages, which in turn contributes to age-related decline in some aspects of attention, such as the inhibition of irrelevant information and the coordination of multiple tasks. However, some age-related preservation of attentional functioning is also evident, particularly the top-down allocation of attention. Neuroimaging research has identified networks of frontal and parietal brain regions relevant for top-down and bottom-up attentional processing. Disconnection among these networks contributes to an age-related decline in attention, but preservation and perhaps even increased patterns of functional brain activation and connectivity also contribute to preserved attentional functioning.


2006 ◽  
Vol 42 ◽  
pp. 206-224 ◽  
Author(s):  
Trevor Johnson

It is now over two decades since a cluster of studies by Natalie Zemon Davis, Bob Scribner, Marc Venard, Roger Chartier, Richard Trexler, William Christian, Carlo Ginzburg and others significantly modified our ways of thinking about religion in early modern Europe and in particular about the relationship between ‘elite’ and ‘popular’ religion, or as many had conceived it, between religion as preached and religion as practised. It had been simpler when writers who thought about such things had drawn neat boundaries between elite and popular and regarded communication between them as an exclusively one-way, top-down, process. They had also tended to regard the popular aspect of the polarity as qualitatively inferior to its elite corollary, depicting it variously as instrumental, functional, un-spiritual, somatic, irrational, unreflective, mechanical, amoral, magical or superstitious, or indeed as all of these things together, as if ‘the people’, a group generally defined in class terms as the socially subordinate, exhibited a vast collective unconscious. Additionally, much ethnography had taken such a divide as axiomatic, the GermanVolkskundetradition, for example, often positing a process of transmission or ‘sinking’ of cultural forms from the elite down to the popular level. Such assumptions, which moreover uncritically reflected a notion of ‘religion’ which is restricted to a formal doctrinal corpus, defined and authenticated by the very body charged with its maintenance, were damaged by the historical revolution of the 1970s and 1980s and will not do for most scholars now, despite having informed a number of still influential historical schemata.


2021 ◽  
Author(s):  
Jee Yoon Bang ◽  
Julia Sunstrum ◽  
Danielle Garand ◽  
Gustavo Morrone Parfitt ◽  
Melanie Woodin ◽  
...  

Preys use their memory - where they sensed a predatory threat and whether a safe shelter is nearby - to dynamically control their survival instinct to avoid harm and reach safety. However, it remains unknown which brain regions are involved, and how such top-down control of innate behaviour is implemented at the circuit level. Here, we show that the anterior hypothalamic nucleus (AHN) is best positioned to perform this task as an exclusive target of the hippocampus (HPC) within the medial hypothalamic defense system. Selective optogenetic stimulation and inhibition of hippocampal inputs to the AHN revealed that the HPC→AHN pathway not only mediates the contextual memory of predator threats but also controls the goal-directed escape by transmitting information about the surrounding environment. These results reveal a new mechanism for experience-dependent, top-down control of innate defensive behaviours.


Author(s):  
Pablo de Almeida ◽  
José Neto

This study aimed to explore whether the processing of cataphoric coreference in Brazilian Portuguese (BP) is guided by a top-down strategy as postulated by the active search mechanism (ASM) or by a bottom-up routine, as well as if this process is restricted by the Principle C constraint. The results revealed that ASM is not a mechanism used to solve the intended coreference in BP and that the participants have demonstrated sensitiveness to establish the coreference while they had to interpret it. In addition, there is evidence that illicit antecedents are not considered during cataphoric resolution, which suggests that the Principle C constraint impacts on the processing and seems to not be violated during the time course of the computation.


2021 ◽  
Author(s):  
En Yang ◽  
Maarten F Zwart ◽  
Mikail Rubinov ◽  
Ben James ◽  
Ziqiang Wei ◽  
...  

To accurately track self-location, animals need to integrate their movements through space. In amniotes, representations of self-location have been found in regions such as the hippocampus. It is unknown whether more ancient brain regions contain such representations and by which pathways they may drive locomotion. Fish displaced by water currents must prevent uncontrolled drift to potentially dangerous areas. We found that larval zebrafish track such movements and can later swim back to their earlier location. Whole-brain functional imaging revealed the circuit enabling this process of positional homeostasis. Position-encoding brainstem neurons integrate optic flow, then bias future swimming to correct for past displacements by modulating inferior olive and cerebellar activity. Manipulation of position-encoding or olivary neurons abolished positional homeostasis or evoked behavior as if animals had experienced positional shifts. These results reveal a multiregional hindbrain circuit in vertebrates for optic flow integration, memory of self-location, and its neural pathway to behavior.


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