scholarly journals Neurons in the pigeon visual network discriminate between faces, scrambled faces, and sine grating images

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
William Clark ◽  
Matthew Chilcott ◽  
Amir Azizi ◽  
Roland Pusch ◽  
Kate Perry ◽  
...  
Keyword(s):  
Hierarchical Organization ◽  
Critical Function ◽  
Linear Discriminant ◽  
Object Categories ◽  
Electrophysiological Recordings ◽  
Early Visual Cortex ◽  
Primate System ◽  
Avian Visual System ◽  
Tectofugal Pathway ◽  
Visual Network

AbstractDiscriminating between object categories (e.g., conspecifics, food, potential predators) is a critical function of the primate and bird visual systems. We examined whether a similar hierarchical organization in the ventral stream that operates for processing faces in monkeys also exists in the avian visual system. We performed electrophysiological recordings from the pigeon Wulst of the thalamofugal pathway, in addition to the entopallium (ENTO) and mesopallium ventrolaterale (MVL) of the tectofugal pathway, while pigeons viewed images of faces, scrambled controls, and sine gratings. A greater proportion of MVL neurons fired to the stimuli, and linear discriminant analysis revealed that the population response of MVL neurons distinguished between the stimuli with greater capacity than ENTO and Wulst neurons. While MVL neurons displayed the greatest response selectivity, in contrast to the primate system no neurons were strongly face-selective and some responded best to the scrambled images. These findings suggest that MVL is primarily involved in processing the local features of images, much like the early visual cortex.

scholarly journals Preparatory Activity in Posterior Temporal Cortex Causally Contributes to Object Detection in Scenes

2015 ◽  
Vol 27 (11) ◽  
pp. 2117-2125 ◽  
Author(s):  
Reshanne R. Reeder ◽  
Francesca Perini ◽  
Marius V. Peelen
Keyword(s):  
Visual Cortex ◽  
Object Detection ◽  
Activity Patterns ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Visual Selective Attention ◽  
Object Categories ◽  
Preparatory Attention ◽  
Preparatory Activity ◽  
Early Visual Cortex

Theories of visual selective attention propose that top–down preparatory attention signals mediate the selection of task-relevant information in cluttered scenes. Neuroimaging and electrophysiology studies have provided correlative evidence for this hypothesis, finding increased activity in target-selective neural populations in visual cortex in the period between a search cue and target onset. In this study, we used online TMS to test whether preparatory neural activity in visual cortex is causally involved in naturalistic object detection. In two experiments, participants detected the presence of object categories (cars, people) in a diverse set of photographs of real-world scenes. TMS was applied over a region in posterior temporal cortex identified by fMRI as carrying category-specific preparatory activity patterns. Results showed that TMS applied over posterior temporal cortex before scene onset (−200 and −100 msec) impaired the detection of object categories in subsequently presented scenes, relative to vertex and early visual cortex stimulation. This effect was specific to category level detection and was related to the type of attentional template participants adopted, with the strongest effects observed in participants adopting category level templates. These results provide evidence for a causal role of preparatory attention in mediating the detection of objects in cluttered daily-life environments.

scholarly journals Active information maintenance in working memory by a sensory cortex

2018 ◽  
Author(s):  
Xiaoxing Zhang ◽  
Wenjun Yan ◽  
Wenliang Wang ◽  
Hongmei Fan ◽  
Ruiqing Hou ◽  
...  
Keyword(s):  
Working Memory ◽  
Piriform Cortex ◽  
Delay Period ◽  
Sensory Cortex ◽  
Critical Function ◽  
Impaired Performance ◽  
Anterior Piriform Cortex ◽  
Electrophysiological Recordings ◽  
Dual Task Paradigm ◽  
The Brain

SummaryWorking memory is a critical function of the brain to maintain and manipulate information over delay periods of seconds. Sensory areas have been implicated in working memory; however, it is debated whether the delay-period activity of sensory regions is actively maintaining information or passively reflecting top-down inputs. We hereby examined the anterior piriform cortex, an olfactory cortex, in head-fixed mice performing a series of olfactory working memory tasks. Information maintenance is necessary in these tasks, especially in a dual-task paradigm in which mice are required to perform another distracting task while actively maintaining information during the delay period. Optogenetic suppression of the piriform cortex activity during the delay period impaired performance in all the tasks.Furthermore, electrophysiological recordings revealed that the delay-period activity of the anterior piriform cortex encoded odor information with or without the distracting task.Thus, this sensory cortex is critical for active information maintenance in working memory.

scholarly journals Rapid Extraction of Emotion Regularities from Complex Scenes in the Human Brain

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Antonio Schettino ◽  
Christopher Gundlach ◽  
Matthias M. Müller
Keyword(s):  
Adaptive Behavior ◽  
Perceptual Load ◽  
Relevant Information ◽  
Complex Scene ◽  
Emotional Cues ◽  
Rapid Extraction ◽  
Electrophysiological Recordings ◽  
Electrophysiological Responses ◽  
Early Visual Cortex ◽  
Scene Processing

Adaptive behavior requires the rapid extraction of behaviorally relevant information in the environment, with particular emphasis on emotional cues. However, the speed of emotional feature extraction from complex visual environments is largely undetermined. Here we use objective electrophysiological recordings in combination with frequency tagging to demonstrate that the extraction of emotional information from neutral, pleasant, or unpleasant naturalistic scenes can be completed at a presentation speed of 167 ms (i.e., 6 Hz) under high perceptual load. Emotional compared to neutral pictures evoked enhanced electrophysiological responses with distinct topographical activation patterns originating from different neural sources. Cortical facilitation in early visual cortex was also more pronounced for scenes with pleasant compared to unpleasant or neutral content, suggesting a positivity offset mechanism dominating under conditions of rapid scene processing. These results significantly advance our knowledge of complex scene processing in demonstrating rapid integrative content identification, particularly for emotional cues relevant for adaptive behavior in complex environments.

Effects of serial lesions of telencephalic components of the visual system in pigeons

1988 ◽  
Vol 1 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Nell M. Riley ◽  
William Hodos ◽  
Tatiana Pasternak
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Pattern Discrimination ◽  
Color Intensity ◽  
Sequence Of Events ◽  
Serial Lesion ◽  
Avian Visual System ◽  
The One ◽  
Tectofugal Pathway ◽  
Made In

AbstractA serial-lesion technique was used to investigate interactions in visual processing between telencephalic components of the pigeon visual system. Pigeons were trained to discriminate pairs of stimuli that differed in color, intensity or pattern. After mastering the discrimination tasks, they were assigned to one of three groups. The first group (WI-EII) received lesions of the visual Wulst and were retested. After the discrimination tasks were again mastered, a second set of lesions was made, this time in the ectostriatum. The birds were tested once again after the second surgery. The second group (EI-WII), underwent the same sequence of events except that the order of the lesions was reversed. In the third group (E + W), lesions of both the visual Wulst and ectostriatum were made in a single operation, followed by retesting. The performance after the first lesion of the subjects in each of the two-stage lesion groups was typical of performance after such lesions; i.e. the birds with visual-Wulst lesions showed little or no impairment on any of the tasks, whereas the pigeons with ectostriatum lesions showed considerable deficits in intensity and pattern discrimination, which diminished after prolonged retraining. In contrast, the pigeons in the one-stage group (E + W) showed profound deficits that appeared to be permanent. The performance after the second operation of the WI-EII group was the same as that of pigeons with lesions of ectostriatum alone; i.e. destruction of ectostriatum first or second resulted in the same duration of impairment. The performance of the EI-WII group after its visual Wulst lesion, however, was similar to that observed in the E + W group. The results are interpreted as a reflection of parallel processing within the avian visual system; i.e. the presence of an intact tectofugal pathway may mask the effects of thalamofugal pathway interruption.

Basic Level Category Structure Emerges Gradually across Human Ventral Visual Cortex

2015 ◽  
Vol 27 (7) ◽  
pp. 1427-1446 ◽  
Author(s):  
Marius Cătălin Iordan ◽  
Michelle R. Greene ◽  
Diane M. Beck ◽  
Li Fei-Fei
Keyword(s):  
Visual Cortex ◽  
Activity Patterns ◽  
Object Categories ◽  
Visual Hierarchy ◽  
Subordinate Level ◽  
Early Visual Cortex ◽  
Occipitotemporal Cortex ◽  
Feature Overlap ◽  
The Brain ◽  
Basic Level

Objects can be simultaneously categorized at multiple levels of specificity ranging from very broad (“natural object”) to very distinct (“Mr. Woof”), with a mid-level of generality (basic level: “dog”) often providing the most cognitively useful distinction between categories. It is unknown, however, how this hierarchical representation is achieved in the brain. Using multivoxel pattern analyses, we examined how well each taxonomic level (superordinate, basic, and subordinate) of real-world object categories is represented across occipitotemporal cortex. We found that, although in early visual cortex objects are best represented at the subordinate level (an effect mostly driven by low-level feature overlap between objects in the same category), this advantage diminishes compared to the basic level as we move up the visual hierarchy, disappearing in object-selective regions of occipitotemporal cortex. This pattern stems from a combined increase in within-category similarity (category cohesion) and between-category dissimilarity (category distinctiveness) of neural activity patterns at the basic level, relative to both subordinate and superordinate levels, suggesting that successive visual areas may be optimizing basic level representations.

scholarly journals A Varying Role for Abstraction in Models of Category Learning Constructed from Neural Representations in Early Visual Cortex

2019 ◽  
Vol 31 (1) ◽  
pp. 155-173 ◽  
Author(s):  
J. Brendan Ritchie ◽  
Hans Op de Beeck
Keyword(s):  
Visual Cortex ◽  
Category Learning ◽  
Neural Representation ◽  
Neural Responses ◽  
Object Categories ◽  
Neural Representations ◽  
Learning Tasks ◽  
Multiple Dimensions ◽  
Wide Range ◽  
Early Visual Cortex

The human capacity for visual categorization is core to how we make sense of the visible world. Although a substantive body of research in cognitive neuroscience has localized this capacity to regions of human visual cortex, relatively few studies have investigated the role of abstraction in how representations for novel object categories are constructed from the neural representation of stimulus dimensions. Using human fMRI coupled with formal modeling of observer behavior, we assess a wide range of categorization models that vary in their level of abstraction from collections of subprototypes to representations of individual exemplars. The category learning tasks range from simple linear and unidimensional category rules to complex crisscross rules that require a nonlinear combination of multiple dimensions. We show that models based on neural responses in primary visual cortex favor a variable, but often limited, extent of abstraction in the construction of representations for novel categories, which differ in degree across tasks and individuals.

scholarly journals Rapid extraction of emotion regularities from complex scenes in the human brain

2018 ◽  
Author(s):  
Antonio Schettino ◽  
Christopher Gundlach ◽  
Matthias M. Müller
Keyword(s):  
Adaptive Behavior ◽  
Perceptual Load ◽  
Relevant Information ◽  
Complex Scene ◽  
Emotional Cues ◽  
Rapid Extraction ◽  
Electrophysiological Recordings ◽  
Electrophysiological Responses ◽  
Early Visual Cortex ◽  
Scene Processing

Adaptive behavior requires the rapid extraction of behaviorally relevant information in the environment, with particular emphasis on emotional cues. However, the speed of emotional feature extraction from complex visual environments is largely undetermined. Here we use objective electrophysiological recordings in combination with frequency tagging to demonstrate that the extraction of emotional information from neutral, pleasant, or unpleasant naturalistic scenes can be completed at a presentation speed of 167 ms (i.e., 6 Hz) under high perceptual load. Emotional compared to neutral pictures evoked enhanced electrophysiological responses with distinct topographical activation patterns originating from different neural sources. Cortical facilitation in early visual cortex was also more pronounced for scenes with pleasant compared to unpleasant or neutral content, suggesting a positivity offset mechanism dominating under conditions of rapid scene processing. These results significantly advance our knowledge of complex scene processing in demonstrating rapid integrative content identification, particularly for emotional cues relevant for adaptive behavior in complex environments.

Patterns of Activity in the Categorical Representations of Objects

2003 ◽  
Vol 15 (5) ◽  
pp. 704-717 ◽  
Author(s):  
Thomas A. Carlson ◽  
Paul Schrater ◽  
Sheng He
Keyword(s):  
Object Perception ◽  
Classification Problem ◽  
Matching Task ◽  
Minimal Effect ◽  
Imaging Data ◽  
Current Analysis ◽  
Linear Discriminant ◽  
Object Categories ◽  
Collective Information ◽  
The Brain

Object perception has been a subject of extensive fMRI studies in recent years. Yet the nature of the cortical representation of objects in the human brain remains controversial. Analyses of fMRI data have traditionally focused on the activation of individual voxels associated with presentation of various stimuli. The current analysis approaches functional imaging data as collective information about the stimulus. Linking activity in the brain to a stimulus is treated as a pattern-classification problem. Linear discriminant analysis was used to reanalyze a set of data originally published by Ishai et al. (2000), available from the fMRIDC (accession no. 2-20001113D). Results of the new analysis reveal that patterns of activity that distinguish one category of objects from other categories are largely independent of one another, both in terms of the activity and spatial overlap. The information used to detect objects from phase-scrambled control stimuli is not essential in distinguishing one object category from another. Furthermore, performing an object-matching task during the scan significantly improved the ability to predict objects from controls, but had minimal effect on object classification, suggesting that the task-based attentional benefit was nonspecific to object categories.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

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