scholarly journals Olfaction Modulates Early Neural Responses to Matching Visual Objects

2015 ◽  
Vol 27 (4) ◽  
pp. 832-841 ◽  
Author(s):  
Amanda K. Robinson ◽  
Judith Reinhard ◽  
Jason B. Mattingley
Keyword(s):  
Neural Activity ◽  
Visual Processing ◽  
Sensory Information ◽  
Neural Correlates ◽  
Neural Responses ◽  
Visual Objects ◽  
Cortical Areas ◽  
Early Visual Processing ◽  
Considerable Research ◽  
Matter Concentration

Sensory information is initially registered within anatomically and functionally segregated brain networks but is also integrated across modalities in higher cortical areas. Although considerable research has focused on uncovering the neural correlates of multisensory integration for the modalities of vision, audition, and touch, much less attention has been devoted to understanding interactions between vision and olfaction in humans. In this study, we asked how odors affect neural activity evoked by images of familiar visual objects associated with characteristic smells. We employed scalp-recorded EEG to measure visual ERPs evoked by briefly presented pictures of familiar objects, such as an orange, mint leaves, or a rose. During presentation of each visual stimulus, participants inhaled either a matching odor, a nonmatching odor, or plain air. The N1 component of the visual ERP was significantly enhanced for matching odors in women, but not in men. This is consistent with evidence that women are superior in detecting, discriminating, and identifying odors and that they have a higher gray matter concentration in olfactory areas of the OFC. We conclude that early visual processing is influenced by olfactory cues because of associations between odors and the objects that emit them, and that these associations are stronger in women than in men.

scholarly journals A neural representation of invisibility: when stimulus-specific neural activity negatively correlates with conscious experience

2020 ◽  
Author(s):  
Matthew J Davidson ◽  
Will Mithen ◽  
Hinze Hogendoorn ◽  
Jeroen J.A. van Boxtel ◽  
Naotsugu Tsuchiya
Keyword(s):  
Neural Activity ◽  
Conscious Experience ◽  
Visual Awareness ◽  
Neural Correlates ◽  
Focus Of Attention ◽  
Neural Representation ◽  
Visually Evoked Potentials ◽  
Neural Responses ◽  
Visual Objects ◽  
Human Participants

AbstractAlthough visual awareness of an object typically increases neural responses, we identify a neural response that increases prior to perceptual disappearances, and that scales with the amount of invisibility reported during perceptual filling-in. These findings challenge long-held assumptions regarding the neural correlates of consciousness and entrained visually evoked potentials, by showing that the strength of stimulus-specific neural activity can encode the conscious absence of a stimulus.Significance StatementThe focus of attention and the contents of consciousness frequently overlap. Yet what happens if this common correlation is broken? To test this, we asked human participants to attend and report on the invisibility of four visual objects which seemed to disappear, yet actually remained on screen. We found that neural activity increased, rather than decreased, when targets became invisible. This coincided with measures of attention that also increased when stimuli disappeared. Together, our data support recent suggestions that attention and conscious perception are distinct and separable. In our experiment, neural measures more strongly follow attention.

Motion-Induced Blindness

2017 ◽  
Author(s):  
Yoram Bonneh
Keyword(s):  
Visual Processing ◽  
Neural Correlates ◽  
Visual Signal ◽  
Low Level ◽  
Neural Correlates Of Consciousness ◽  
Visual Objects ◽  
Multistable Perception ◽  
Residual Processing ◽  
Potential Use ◽  
Moving Pattern

Motion-induced blindness (MIB) is a phenomenon characterized by “visual disappearance” in which relatively small but salient visual objects may disappear from one’s awareness intermittently for several seconds when embedded within a moving pattern. It is a compelling example of multistable perception in which physically invariant stimulation leads to fluctuations in perception. The interest in MIB stems from its potential use in studying visual processing outside the locus of awareness and the neural correlates of consciousness. Current studies of MIB provide evidence against low-level suppression of the visual signal and demonstrate residual processing of the invisible. This chapter explores these and related concepts.

scholarly journals Understanding heterosexual women’s erotic flexibility: the role of attention in sexual evaluations and neural responses to sexual stimuli

2020 ◽  
Vol 15 (4) ◽  
pp. 447-465
Author(s):  
Janna A Dickenson ◽  
Lisa Diamond ◽  
Jace B King ◽  
Kay Jenson ◽  
Jeffrey S Anderson
Keyword(s):  
Sexual Orientation ◽  
Neural Activity ◽  
Visual Processing ◽  
Neural Responses ◽  
Attentional Processing ◽  
Sexual Stimuli ◽  
Mindful Attention ◽  
Heterosexual Women ◽  
And Behavior

Abstract Many women experience desires, arousal and behavior that run counter to their sexual orientation (orientation inconsistent, ‘OI’). Are such OI sexual experiences cognitively and neurobiologically distinct from those that are consistent with one’s sexual orientation (orientation consistent, ‘OC’)? To address this question, we employed a mindful attention intervention—aimed at reducing judgment and enhancing somatosensory attention—to examine the underlying attentional and neurobiological processes of OC and OI sexual stimuli among predominantly heterosexual women. Women exhibited greater neural activity in response to OC, compared to OI, sexual stimuli in regions associated with implicit visual processing, volitional appraisal and attention. In contrast, women exhibited greater neural activity to OI, relative to OC, sexual stimuli in regions associated with complex visual processing and attentional shifting. Mindfully attending to OC sexual stimuli reduced distraction, amplified women’s evaluations of OC stimuli as sexually arousing and deactivated the superior cerebellum. In contrast, mindfully attending to OI sexual stimuli amplified distraction, decreased women’s evaluations of OI stimuli as sexually arousing and augmented parietal and temporo-occipital activity. Results of the current study constrain hypotheses of female erotic flexibility, suggesting that sexual orientation may be maintained by differences in attentional processing that cannot be voluntarily altered.

scholarly journals Increased influence of periphery on central visual processing in humans during walking

2018 ◽  
Author(s):  
Liyu Cao ◽  
Barbara Händel
Keyword(s):  
Sensory Processing ◽  
Visual Processing ◽  
Sensory Information ◽  
Human Perception ◽  
Neural Responses ◽  
Natural Behaviour ◽  
Visual Areas ◽  
Sensory Information Processing ◽  
Visual Cortical ◽  
Behavioural Evidence

AbstractCognitive processes are almost exclusively investigated under highly controlled settings while voluntary body movements are suppressed. However, recent animal work suggests differences in sensory processing between movement states by showing drastically changed neural responses in early visual areas between locomotion and stillness. Does locomotion also modulate visual cortical activity in humans and what are its perceptual consequences? Here, we present converging neurophysiological and behavioural evidence that walking leads to an increased influence of peripheral stimuli on central visual input. This modulation of visual processing due to walking is encompassed by a change in alpha oscillations, which is suggestive of an attentional shift to the periphery during walking. Overall, our study shows that strategies of sensory information processing can differ between movement states. This finding further demonstrates that a comprehensive understanding of human perception and cognition critically depends on the consideration of natural behaviour.

scholarly journals Neural Responses in Dorsal Prefrontal Cortex Reflect Proactive Interference during an Auditory Reversal Task

2018 ◽  
Author(s):  
Nikolas A. Francis ◽  
Susanne Radtke-Schuller ◽  
Jonathan B. Fritz ◽  
Shihab A. Shamma
Keyword(s):  
Prefrontal Cortex ◽  
Frontal Cortex ◽  
Proactive Interference ◽  
Cognitive Flexibility ◽  
Neural Activity ◽  
Neural Correlates ◽  
Neural Responses ◽  
Reversal Task ◽  
Neural Correlate ◽  
The Brain

AbstractTask-related plasticity in the brain is triggered by changes in the behavioral meaning of sounds. We investigated plasticity in ferret dorsolateral frontal cortex (dlFC) during an auditory reversal task to study the neural correlates of proactive interference, i.e., perseveration of previously learned behavioral meanings that are no longer task-appropriate. Although the animals learned the task, target recognition decreased after reversals, indicating proactive interference. Frontal cortex responsiveness was consistent with previous findings that dlFC encodes the behavioral meaning of sounds. However, the neural responses observed here were more complex. For example, target responses were strongly enhanced, while responses to non-target tones and noises were weakly enhanced and strongly suppressed, respectively. Moreover, dlFC responsiveness reflected the proactive interference observed in behavior: target responses decreased after reversals, most significantly during incorrect behavioral responses. These findings suggest that the weak representation of behavioral meaning in dlFC may be a neural correlate of proactive interference.Significance StatementNeural activity in prefrontal cortex (PFC) is believed to enable cognitive flexibility during sensory-guided behavior. Since PFC encodes the behavioral meaning of sensory events, we hypothesized that weak representation of behavioral meaning in PFC may limit cognitive flexibility. To test this hypothesis, we recorded neural activity in ferret PFC, while ferrets performed an auditory reversal task in which the behavioral meanings of sounds were reversed during experiments. The reversal task enabled us study PFC responses during proactive interference, i.e. perseveration of previously learned behavioral meanings that are no longer task-appropriate. We found that task performance errors increased after reversals while PFC representation of behavioral meaning diminished. Our findings suggest that proactive interference may occur when PFC forms weak sensory-cognitive associations.

scholarly journals Transformation of population code from dLGN to V1 facilitates linear decoding

2019 ◽  
Author(s):  
N. Alex Cayco Gajic ◽  
Séverine Durand ◽  
Michael Buice ◽  
Ramakrishnan Iyer ◽  
Clay Reid ◽  
...  
Keyword(s):  
Sparse Coding ◽  
Visual Processing ◽  
Brain Area ◽  
Sensory Information ◽  
V1 Neurons ◽  
Linear Separability ◽  
Early Visual Processing ◽  
Neural Populations ◽  
Linear Decoding

SummaryHow neural populations represent sensory information, and how that representation is transformed from one brain area to another, are fundamental questions of neuroscience. The dorsolateral geniculate nucleus (dLGN) and primary visual cortex (V1) represent two distinct stages of early visual processing. Classic sparse coding theories propose that V1 neurons represent local features of images. More recent theories have argued that the visual pathway transforms visual representations to become increasingly linearly separable. To test these ideas, we simultaneously recorded the spiking activity of mouse dLGN and V1 in vivo. We find strong evidence for both sparse coding and linear separability theories. Surprisingly, the correlations between neurons in V1 (but not dLGN) were shaped as to be irrelevant for stimulus decoding, a feature which we show enables linear separability. Therefore, our results suggest that the dLGN-V1 transformation reshapes correlated variability in a manner that facilitates linear decoding while producing a sparse code.

scholarly journals Neural Correlates of Metamemory: A Comparison of Feeling-of-Knowing and Retrospective Confidence Judgments

2009 ◽  
Vol 21 (9) ◽  
pp. 1751-1765 ◽  
Author(s):  
Elizabeth F. Chua ◽  
Daniel L. Schacter ◽  
Reisa A. Sperling
Keyword(s):  
Neural Activity ◽  
Visual Processing ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Neural Correlates ◽  
Neural Mechanisms ◽  
Multiple Forms ◽  
Functional Roles ◽  
Feeling Of Knowing ◽  
Metamemory Monitoring

Metamemory refers to knowledge and monitoring of one's own memory. Metamemory monitoring can be done prospectively with respect to subsequent memory retrieval or retrospectively with respect to previous memory retrieval. In this study, we used fMRI to compare neural activity during prospective feeling-of-knowing and retrospective confidence tasks in order to examine common and distinct mechanisms supporting multiple forms of metamemory monitoring. Both metamemory tasks, compared to non-metamemory tasks, were associated with greater activity in medial prefrontal, medial parietal, and lateral parietal regions, which have previously been implicated in internally directed cognition. Furthermore, compared to non-metamemory tasks, metamemory tasks were associated with less activity in occipital regions, and in lateral inferior frontal and dorsal medial prefrontal regions, which have previously shown involvement in visual processing and stimulus-oriented attention, respectively. Thus, neural activity related to metamemory is characterized by both a shift toward internally directed cognition and away from externally directed cognition. Several regions demonstrated differences in neural activity between feeling-of-knowing and confidence tasks, including fusiform, medial temporal lobe, and medial parietal regions; furthermore, these regions also showed interaction effects between task and the subjective metamemory rating, suggesting that they are sensitive to the information monitored in each particular task. These findings demonstrate both common and distinct neural mechanisms supporting metamemory processes and also serve to elucidate the functional roles of previously characterized brain networks.

scholarly journals Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex

2021 ◽  
Author(s):  
Simen Hagen ◽  
Aliette Lochy ◽  
Corentin Jacques ◽  
Louis Maillard ◽  
Sophie Colnat-Coulbois ◽  
...  
Keyword(s):  
Neural Activity ◽  
Word Processing ◽  
Temporal Cortex ◽  
Neural Circuitry ◽  
Hemispheric Dominance ◽  
Strong Correlations ◽  
Visual Responses ◽  
Neural Responses ◽  
Visual Objects ◽  
Face Selectivity

AbstractThe extent to which faces and written words share neural circuitry in the human brain is actively debated. Here, we compare face-selective and word-selective responses in a large group of patients (N = 37) implanted with intracerebral electrodes in the ventral occipito-temporal cortex (VOTC). Both face-selective (i.e., significantly different responses to faces vs. non-face visual objects) and word-selective (i.e., significantly different responses to words vs. pseudofonts) neural activity is isolated with frequency-tagging. Critically, this sensitive approach allows to objectively quantify category-selective neural responses and disentangle them from general visual responses. About 70% of significant electrode contacts show either face-selectivity or word-selectivity only, with the expected right and left hemispheric dominance, respectively. Spatial dissociations are also found within core regions of face and word processing, with a medio-lateral dissociation in the fusiform gyrus (FG) and surrounding sulci, respectively. In the 30% of overlapping face- and word-selective contacts across the VOTC or in the FG and surrounding sulci, between-category-selective amplitudes (faces vs. words) show no-to-weak correlations, despite strong correlations in both the within-category-selective amplitudes (face–face, word–word) and the general visual responses to words and faces. Overall, these observations support the view that category-selective circuitry for faces and written words is largely dissociated in the human adult VOTC.

Visual and Tactile Information About Object-Curvature Control Fingertip Forces and Grasp Kinematics in Human Dexterous Manipulation

2000 ◽  
Vol 84 (6) ◽  
pp. 2984-2997 ◽  
Author(s):  
Per Jenmalm ◽  
Seth Dahlstedt ◽  
Roland S. Johansson
Keyword(s):  
Visual Processing ◽  
Visual Cues ◽  
Grip Force ◽  
Center Of Mass ◽  
Precision Grip ◽  
Sensory Information ◽  
Afferent Input ◽  
Dependent Manner ◽  
Tactile Sensibility ◽  
Grasp Stability

Most objects that we manipulate have curved surfaces. We have analyzed how subjects during a prototypical manipulatory task use visual and tactile sensory information for adapting fingertip actions to changes in object curvature. Subjects grasped an elongated object at one end using a precision grip and lifted it while instructed to keep it level. The principal load of the grasp was tangential torque due to the location of the center of mass of the object in relation to the horizontal grip axis joining the centers of the opposing grasp surfaces. The curvature strongly influenced the grip forces required to prevent rotational slips. Likewise the curvature influenced the rotational yield of the grasp that developed under the tangential torque load due to the viscoelastic properties of the fingertip pulps. Subjects scaled the grip forces parametrically with object curvature for grasp stability. Moreover in a curvature-dependent manner, subjects twisted the grasp around the grip axis by a radial flexion of the wrist to keep the desired object orientation despite the rotational yield. To adapt these fingertip actions to object curvature, subjects could use both vision and tactile sensibility integrated with predictive control. During combined blindfolding and digital anesthesia, however, the motor output failed to predict the consequences of the prevailing curvature. Subjects used vision to identify the curvature for efficient feedforward retrieval of grip force requirements before executing the motor commands. Digital anesthesia caused little impairment of grip force control when subjects had vision available, but the adaptation of the twist became delayed. Visual cues about the form of the grasp surface obtained before contact was used to scale the grip force, whereas the scaling of the twist depended on visual cues related to object movement. Thus subjects apparently relied on different visuomotor mechanisms for adaptation of grip force and grasp kinematics. In contrast, blindfolded subjects used tactile cues about the prevailing curvature obtained after contact with the object for feedforward adaptation of both grip force and twist. We conclude that humans use both vision and tactile sensibility for feedforward parametric adaptation of grip forces and grasp kinematics to object curvature. Normal control of the twist action, however, requires digital afferent input, and different visuomotor mechanisms support the control of the grasp twist and the grip force. This differential use of vision may have a bearing to the two-stream model of human visual processing.

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