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Article ; Online: Solving the binding problem: Assemblies form when neurons enhance their firing rate-they don't need to oscillate or synchronize.

Roelfsema, Pieter R

2023 Volume 111, Issue 7, Page(s) 1003–1019

Abstract: When we look at an image, its features are represented in our visual system in a highly distributed manner, calling for a mechanism that binds them into coherent object representations. There have been different proposals for the neuronal mechanisms that ...

Abstract	When we look at an image, its features are represented in our visual system in a highly distributed manner, calling for a mechanism that binds them into coherent object representations. There have been different proposals for the neuronal mechanisms that can mediate binding. One hypothesis is that binding is achieved by oscillations that synchronize neurons representing features of the same perceptual object. This view allows separate communication channels between different brain areas. Another hypothesis is that binding of features that are represented in different brain regions occurs when the neurons in these areas that respond to the same object simultaneously enhance their firing rate, which would correspond to directing object-based attention to these features. This review summarizes evidence in favor of and against these two hypotheses, examining the neuronal correlates of binding and assessing the time course of perceptual grouping. I conclude that enhanced neuronal firing rates bind features into coherent object representations, whereas oscillations and synchrony are unrelated to binding.
MeSH term(s)	Brain ; Neurons/physiology ; Visual Perception/physiology
Language	English
Publishing date	2023-04-01
Publishing country	United States
Document type	Journal Article ; Review ; Research Support, Non-U.S. Gov't
ZDB-ID	808167-0
ISSN	1097-4199 ; 0896-6273
ISSN (online)	1097-4199
ISSN	0896-6273
DOI	10.1016/j.neuron.2023.03.016
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Zs.MG 92: Show issues

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Article ; Online: Writing to the Mind's Eye of the Blind.

Roelfsema, Pieter R

Cell

2020 Volume 181, Issue 4, Page(s) 758–759

Abstract: The implantation of electrodes on the visual cortex of blind individuals could lead to the restoration of a rudimentary form of sight. In this issue of Cell, Beauchamp et al. use electrical stimulation of the visual cortex to create visual perception of ... ...

Abstract	The implantation of electrodes on the visual cortex of blind individuals could lead to the restoration of a rudimentary form of sight. In this issue of Cell, Beauchamp et al. use electrical stimulation of the visual cortex to create visual perception of shapes.
MeSH term(s)	Eye ; Humans ; Visual Cortex ; Visual Perception ; Writing
Language	English
Publishing date	2020-05-15
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't ; Comment
ZDB-ID	187009-9
ISSN	1097-4172 ; 0092-8674
ISSN (online)	1097-4172
ISSN	0092-8674
DOI	10.1016/j.cell.2020.03.014
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Zs.A 1167: Show issues			Location: Je nach Verfügbarkeit (siehe Angabe bei Bestand) bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular Jg. 1995 - 2021: Lesesall (1.OG) ab Jg. 2022: Lesesaal (EG)
Zs.MG 58: Show issues

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Article ; Online: Flexible Polymer Electrodes for Stable Prosthetic Visual Perception in Mice.

Orlemann, Corinne / Boehler, Christian / Kooijmans, Roxana N / Li, Bingshuo / Asplund, Maria / Roelfsema, Pieter R

Advanced healthcare materials

2024 , Page(s) e2304169

Abstract: Brain interfaces that can stimulate neurons, cause minimal damage, and work for a long time will be central for future neuroprosthetics. Here, the long-term performance of highly flexible, thin polyimide shanks with several small (<15 µm) electrodes ... ...

Abstract	Brain interfaces that can stimulate neurons, cause minimal damage, and work for a long time will be central for future neuroprosthetics. Here, the long-term performance of highly flexible, thin polyimide shanks with several small (<15 µm) electrodes during electrical microstimulation of the visual cortex, is reported. The electrodes exhibit a remarkable stability when several billions of electrical pulses are applied in vitro. When the devices are implanted in the primary visual cortex (area V1) of mice and the animals are trained to detect electrical microstimulation, it is found that the perceptual thresholds are 2-20 microamperes (µA), which is far below the maximal currents that the electrodes can withstand. The long-term functionality of the devices in vivo is excellent, with stable performance for up to more than a year and little damage to the brain tissue. These results demonstrate the potential of thin floating electrodes for the long-term restoration of lost sensory functions.
Language	English
Publishing date	2024-02-07
Publishing country	Germany
Document type	Journal Article
ZDB-ID	2649576-4
ISSN	2192-2659 ; 2192-2640
ISSN (online)	2192-2659
ISSN	2192-2640
DOI	10.1002/adhm.202304169
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Article ; Online: Contextual drive of neuronal responses in mouse V1 in the absence of feedforward input.

Kirchberger, Lisa / Mukherjee, Sreedeep / Self, Matthew W / Roelfsema, Pieter R

Science advances

2023 Volume 9, Issue 3, Page(s) eadd2498

Abstract: Neurons in the primary visual cortex (V1) respond to stimuli in their receptive field (RF), which is defined by the feedforward input from the retina. However, V1 neurons are also sensitive to contextual information outside their RF, even if the RF ... ...

Abstract	Neurons in the primary visual cortex (V1) respond to stimuli in their receptive field (RF), which is defined by the feedforward input from the retina. However, V1 neurons are also sensitive to contextual information outside their RF, even if the RF itself is unstimulated. Here, we examined the cortical circuits for V1 contextual responses to gray disks superimposed on different backgrounds. Contextual responses began late and were strongest in the feedback-recipient layers of V1. They differed between the three main classes of inhibitory neurons, with particularly strong contextual drive of VIP neurons, indicating a contribution of disinhibitory circuits to contextual drive. Contextual drive was strongest when the gray disk was perceived as figure, occluding its background, rather than a hole. Our results link contextual drive in V1 to perceptual organization and provide previously unknown insight into how recurrent processing shapes the response of sensory neurons to facilitate figure perception.
MeSH term(s)	Mice ; Animals ; Visual Cortex/physiology ; Neurons/physiology ; Retina ; Neurons, Afferent ; Orientation/physiology ; Visual Perception/physiology ; Photic Stimulation/methods
Language	English
Publishing date	2023-01-20
Publishing country	United States
Document type	Journal Article
ZDB-ID	2810933-8
ISSN	2375-2548 ; 2375-2548
ISSN (online)	2375-2548
ISSN	2375-2548
DOI	10.1126/sciadv.add2498
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Article ; Online: Inversion of pop-out for a distracting feature dimension in monkey visual cortex.

Klink, P Christiaan / Teeuwen, Rob R M / Lorteije, Jeannette A M / Roelfsema, Pieter R

Proceedings of the National Academy of Sciences of the United States of America

2023 Volume 120, Issue 9, Page(s) e2210839120

Abstract: During visual search, it is important to reduce the interference of distracting objects in the scene. The neuronal responses elicited by the search target stimulus are typically enhanced. However, it is equally important to suppress the representations ... ...

Abstract	During visual search, it is important to reduce the interference of distracting objects in the scene. The neuronal responses elicited by the search target stimulus are typically enhanced. However, it is equally important to suppress the representations of distracting stimuli, especially if they are salient and capture attention. We trained monkeys to make an eye movement to a unique "pop-out" shape stimulus among an array of distracting stimuli. One of these distractors had a salient color that varied across trials and differed from the color of the other stimuli, causing it to also pop-out. The monkeys were able to select the pop-out shape target with high accuracy and actively avoided the pop-out color distractor. This behavioral pattern was reflected in the activity of neurons in area V4. Responses to the shape targets were enhanced, while the activity evoked by the pop-out color distractor was only briefly enhanced, directly followed by a sustained period of pronounced suppression. These behavioral and neuronal results demonstrate a cortical selection mechanism that rapidly inverts a pop-out signal to "pop-in" for an entire feature dimension thereby facilitating goal-directed visual search in the presence of salient distractors.
MeSH term(s)	Animals ; Color Perception/physiology ; Haplorhini ; Attention/physiology ; Eye Movements ; Visual Cortex/physiology ; Reaction Time/physiology ; Visual Perception/physiology
Language	English
Publishing date	2023-02-22
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	209104-5
ISSN	1091-6490 ; 0027-8424
ISSN (online)	1091-6490
ISSN	0027-8424
DOI	10.1073/pnas.2210839120
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Article ; Online: Neuroscience: Figured Out by Feedback to the Thalamus.

Self, Matthew W / Roelfsema, Pieter R

Current biology : CB

2019 Volume 29, Issue 12, Page(s) R574–R577

Abstract: The lateral geniculate nucleus of the thalamus (LGN) is a relay nucleus between the retina and the visual cortex. A new brain imaging study shows that LGN activity is modulated by figure-ground organization, even when the figure and ground are presented ... ...

Abstract	The lateral geniculate nucleus of the thalamus (LGN) is a relay nucleus between the retina and the visual cortex. A new brain imaging study shows that LGN activity is modulated by figure-ground organization, even when the figure and ground are presented to different eyes: a hallmark of a cortical feedback effect.
MeSH term(s)	Attention ; Geniculate Bodies ; Humans ; Retina ; Thalamus ; Visual Cortex
Language	English
Publishing date	2019-06-18
Publishing country	England
Document type	Journal Article ; Comment
ZDB-ID	1071731-6
ISSN	1879-0445 ; 0960-9822
ISSN (online)	1879-0445
ISSN	0960-9822
DOI	10.1016/j.cub.2019.05.022
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Article ; Online: Reply to 'Can neocortical feedback alter the sign of plasticity?'

Roelfsema, Pieter R / Holtmaat, Anthony

Nature reviews. Neuroscience

2018 Volume 19, Issue 10, Page(s) 637–638

MeSH term(s)	Neocortex ; Neuronal Plasticity
Language	English
Publishing date	2018-06-19
Publishing country	England
Document type	Letter ; Comment
ZDB-ID	2034150-7
ISSN	1471-0048 ; 1471-0048 ; 1471-003X
ISSN (online)	1471-0048
ISSN	1471-0048 ; 1471-003X
DOI	10.1038/s41583-018-0048-6
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Zs.A 5473: Show issues			Location: Je nach Verfügbarkeit (siehe Angabe bei Bestand) bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular Jg. 1995 - 2021: Lesesall (2.OG) ab Jg. 2022: Lesesaal (EG)
Zs.MG 47: Show issues

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Article ; Online: Control of synaptic plasticity in deep cortical networks.

Roelfsema, Pieter R / Holtmaat, Anthony

Nature reviews. Neuroscience

2018 Volume 19, Issue 3, Page(s) 166–180

Abstract: Humans and many other animals have an enormous capacity to learn about sensory stimuli and to master new skills. However, many of the mechanisms that enable us to learn remain to be understood. One of the greatest challenges of systems neuroscience is to ...

Abstract	Humans and many other animals have an enormous capacity to learn about sensory stimuli and to master new skills. However, many of the mechanisms that enable us to learn remain to be understood. One of the greatest challenges of systems neuroscience is to explain how synaptic connections change to support maximally adaptive behaviour. Here, we provide an overview of factors that determine the change in the strength of synapses, with a focus on synaptic plasticity in sensory cortices. We review the influence of neuromodulators and feedback connections in synaptic plasticity and suggest a specific framework in which these factors can interact to improve the functioning of the entire network.
MeSH term(s)	Animals ; Attention/physiology ; Cerebral Cortex/physiology ; Humans ; Learning/physiology ; Models, Neurological ; Neural Pathways/physiology ; Neuronal Plasticity ; Neurons/physiology ; Reward
Language	English
Publishing date	2018-02-16
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't ; Review
ZDB-ID	2034150-7
ISSN	1471-0048 ; 1471-0048 ; 1471-003X
ISSN (online)	1471-0048
ISSN	1471-0048 ; 1471-003X
DOI	10.1038/nrn.2018.6
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Zs.A 5473: Show issues			Location: Je nach Verfügbarkeit (siehe Angabe bei Bestand) bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular Jg. 1995 - 2021: Lesesall (2.OG) ab Jg. 2022: Lesesaal (EG)
Zs.MG 47: Show issues

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Article ; Online: Object Selection by Automatic Spreading of Top-Down Attentional Signals in V1.

Ekman, Matthias / Roelfsema, Pieter R / de Lange, Floris P

The Journal of neuroscience : the official journal of the Society for Neuroscience

2020 Volume 40, Issue 48, Page(s) 9250–9259

Abstract: What is selected when attention is directed to a specific location of the visual field? Theories of object-based attention have suggested that when spatial attention is directed to part of an object, attention does not simply enhance the attended ... ...

Abstract	What is selected when attention is directed to a specific location of the visual field? Theories of object-based attention have suggested that when spatial attention is directed to part of an object, attention does not simply enhance the attended location but automatically spreads to enhance all locations that comprise the object. Here, we tested this hypothesis by reconstructing the distribution of attention from primary visual cortex (V1) population neuronal activity patterns in 24 human adults (17 female) using functional magnetic resonance imaging (fMRI) and population-based receptive field (prf) mapping. We find that attention spreads from a spatially cued location to the underlying object, and enhances all spatial locations that comprise the object. Importantly, this spreading was also evident when the object was not task relevant. These data suggest that attentional selection automatically operates at an object level, facilitating the reconstruction of coherent objects from fragmented representations in early visual cortex.
MeSH term(s)	Adult ; Attention/physiology ; Brain Mapping ; Cues ; Female ; Hemodynamics/physiology ; Humans ; Magnetic Resonance Imaging ; Male ; Photic Stimulation ; Reaction Time/physiology ; Space Perception/physiology ; Visual Cortex/diagnostic imaging ; Visual Cortex/physiology ; Visual Fields/physiology ; Visual Perception/physiology ; Young Adult
Language	English
Publishing date	2020-10-21
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	604637-x
ISSN	1529-2401 ; 0270-6474
ISSN (online)	1529-2401
ISSN	0270-6474
DOI	10.1523/JNEUROSCI.0438-20.2020
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Zs.A 1668: Show issues

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Article ; Online: Attention for action in visual working memory.

Olivers, Christian N L / Roelfsema, Pieter R

Cortex; a journal devoted to the study of the nervous system and behavior

2020 Volume 131, Page(s) 179–194

Abstract: From the conception of Baddeley's visuospatial sketchpad, visual working memory and visual attention have been closely linked concepts. An attractive model has advocated unity of the two cognitive functions, with attention serving the active maintenance ... ...

Abstract	From the conception of Baddeley's visuospatial sketchpad, visual working memory and visual attention have been closely linked concepts. An attractive model has advocated unity of the two cognitive functions, with attention serving the active maintenance of sensory representations. However, empirical evidence from various paradigms and dependent measures has now firmly established an at least partial dissociation between visual attention and visual working memory maintenance - thus leaving unclear what the relationship between the two concepts is. Moreover, a focus on sensory storage has treated visual working memory as a reflection of the past, with attention as a limiting resource. This view ignores what storage is for: immediate or future action. We argue that rather than serving sensory storage, attention emerges from coupling relevant sensory and action representations within working memory. Importantly, this coupling is bidirectional: First, through recurrent feedback mechanisms, action coupling results in the enhancement of the appropriate sensory memory representation. Under this view, unattended memories are currently not coupled to an action plan, but are not necessarily lost and remain available for future tasks when necessary. Second, through the very same feedback projections, attention serves as the credit assignment mechanism for the action's outcome. When the action is successful, the associated representations are being reinforced, leading to more robust consolidation and more rapid retrieval in the future - thus explaining performance benefits for attended memories without assuming that attention serves as the maintenance mechanism. By firmly grounding VWM in the action system, the new framework integrates a range of behavioural and neurophysiological findings and avoids circularity in explaining the role of attention in working memory.
MeSH term(s)	Cognition ; Forecasting ; Humans ; Memory, Short-Term ; Neurophysiology ; Visual Perception
Language	English
Publishing date	2020-08-10
Publishing country	Italy
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	280622-8
ISSN	1973-8102 ; 0010-9452
ISSN (online)	1973-8102
ISSN	0010-9452
DOI	10.1016/j.cortex.2020.07.011
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