Albert Compte

Albert Compte
IDIBAPS August Pi i Sunyer Biomedical Research Institute | IDIBAPS · Division of Clinical and Experimental Neuroscience

PhD

About

106
Publications
10,578
Reads
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5,809
Citations
Additional affiliations
January 2007 - present
Karolinska Institutet
Position
  • Modeling multi-item working memory
October 2006 - present
Institut d’Investigacions Biomèdiques August Pi i Sunyer
Position
  • Cortical network dynamics in memory and attention
January 2002 - October 2006
Universidad Miguel Hernández de Elche
Position
  • Cortical network dynamics in vivo and in vitro
Education
September 1994 - February 1998
Autonomous University of Barcelona
Field of study
  • Statistical Physics

Publications

Publications (106)
Article
Background Anti-NMDA receptor (NMDAR) encephalitis is associated with a post-acute stage that is not well known. We aimed to describe the clinical features of this stage, similarities with schizophrenia spectrum disorders, and the factors that predict cognitive–psychiatric outcomes and could serve as prognostic biomarkers. Methods In this prospect...
Article
Full-text available
Persistently active neurons during mnemonic periods have been regarded as the mechanism underlying working memory maintenance. Alternatively, neuronal networks could instead store memories in fast synaptic changes, thus avoiding the biological cost of maintaining an active code through persistent neuronal firing. Such “activity-silent” codes have b...
Article
Alterations in neuromodulation or synaptic transmission in biophysical attractor network models, as proposed by the dominant dopaminergic and glutamatergic theories of schizophrenia, successfully mimic working memory (WM) deficits in people with schizophrenia (PSZ). Yet, multiple, often opposing alterations in memory circuits can lead to the same b...
Article
Full-text available
Working memory function is severely limited. One key limitation that constrains the ability to maintain multiple items in working memory simultaneously is so-called swap errors. These errors occur when an inaccurate response is in fact accurate relative to a non-target stimulus, reflecting the failure to maintain the appropriate association or “bin...
Article
Full-text available
Acetylcholine plays a critical role in the neocortex. Cholinergic agonists and acetylcholinesterase inhibitors can enhance cognitive functioning, as does intermittent electrical stimulation of the cortical source of acetylcholine, the nucleus basalis (NB) of Meynert. Here we show in two male monkeys how NB stimulation affects working memory and alt...
Preprint
Full-text available
Working memory function is severely limited. One key limitation that constrains the ability to maintain multiple items in working memory simultaneously is so-called swap errors. These errors occur when an inaccurate response is in fact accurate relative to a non-target stimulus, reflecting the failure to maintain the appropriate association or 'bin...
Preprint
Full-text available
Alterations in neuromodulation or synaptic transmission in biophysical attractor network models, as proposed by the dominant dopaminergic and glutamatergic theories of schizophrenia, successfully mimic working memory (WM) deficits in people with schizophrenia (PSZ). Yet, multiple, often opposing circuit mechanisms can lead to the same behavioral pa...
Preprint
Full-text available
A hallmark of the ‘activity-silent’ working memory framework [1] is that memories stored silently in synaptic traces can be reactivated through non-specific stimuli [1–5]. Evidence supporting ‘activity-silent’ working memory has recently emerged from human electroencephalography (EEG) [6,7], in particular from ‘reactivations’ of unattended memories...
Article
Full-text available
Psychophysical tests are commonly carried out using software applications running on desktop or laptop computers, but running the software on mobile handheld devices such as smartphones or tablets could have advantages in some situations. Here, we present StimuliApp, an open-source application in which the user can create psychophysical tests on th...
Article
Full-text available
A mechanistic understanding of core cognitive processes, such as working memory, is crucial to addressing psychiatric symptoms in brain disorders. We propose a combined psychophysical and biophysical account of two symptomatologically related diseases, both linked to hypofunctional NMDARs: schizophrenia and autoimmune anti-NMDAR encephalitis. We fi...
Article
Full-text available
Persistent neuronal spiking has long been considered the mechanism underlying working memory, but recent proposals argue for alternative ‘activity-silent’ substrates. Using monkey and human electrophysiology data, we show here that attractor dynamics that control neural spiking during mnemonic periods interact with activity-silent mechanisms in the...
Article
Full-text available
Serial dependence, how immediately preceding experiences bias our current estimations, has been described experimentally during delayed-estimation of many different visual features, with subjects tending to make estimates biased towards previous ones. It has been proposed that these attractive biases help perception stabilization in the face of cor...
Preprint
Psychophysical tests are commonly carried out running software applications in desktop or laptop computers, but running the software in mobile handheld devices such as smartphones or tablets could have advantages in some situations. Here, we present StimuliApp, an open-source application, in which the user can create psychophysical tests on the iPa...
Article
Objective To describe the sleep disorders in anti-NMDA receptor encephalitis (anti-NMDARe). Methods Patients recovering from anti-NMDARe were invited to participate in a prospective observational single center study including comprehensive clinical, video-polysomnography (V-PSG) sleep assessment and neuropsychological evaluation. Age and sex-match...
Article
Full-text available
Background The N-methyl-D-aspartate receptor (NMDAR) hypofunction model of schizophrenia suggests that dysfunction of these receptors could underlie the brain functional abnormalities characterising these patients. In NMDAR encephalitis (NMDARE), which holds clinical similarities with schizophrenia, autoantibodies target NMDARs, predominantly locat...
Article
Full-text available
Background Perceptual spatial suppression is a phenomenon in which the perceived strength of a stimulus in space is reduced when the stimulus is surrounded by other stimuli. For motion perception, two studies so far have suggested that spatial suppression and sensitivity to motion perception is also reduced in patients with schizophrenia. Studies t...
Article
Full-text available
Perceptual spatial suppression is a phenomenon in which the perceived strength of a stimulus in some region of the space is reduced when the stimulus is surrounded by other stimuli. For contrast perception, several studies suggest that spatial suppression is reduced in patients with schizophrenia. For motion perception, only one study has been cond...
Preprint
Full-text available
We report markedly reduced working memory-related serial dependence with preserved memory accuracy in anti-NMDAR encephalitis and schizophrenia. We argue that NMDAR-related changes in cortical excitation, while quickly destabilizing persistent neural activity, cannot fully account for a reduction of memory-dependent biases. Rather, our modeling res...
Preprint
Full-text available
Perceptual spatial suppression is a phenomenon in which the perceived strength of a stimulus in some region of the space is reduced when the stimulus is surrounded by other stimuli. For contrast perception, several studies suggest that spatial suppression is reduced in patients with schizophrenia. For motion perception, only one study has been cond...
Preprint
Full-text available
Persistent neuronal spiking has long been considered the mechanism underlying working memory, but recent proposals argue for alternative, 'activity-silent' substrates for memory. Using monkey and human electrophysiology, we show here that attractor dynamics that control neural spiking during mnemonic periods interact with activity-silent mechanisms...
Preprint
Full-text available
Serial dependence, how recent experiences bias our current estimations, has been described experimentally during delayed-estimation of many different visual features, with subjects tending to make estimates biased towards previous ones. It has been proposed that these attractive biases help perception stabilization in the face of correlated natural...
Article
Full-text available
The Acknowledgements section in this Article is incomplete. “This work was funded by the Ministry of Economy and Competitiveness of Spain, and the European Regional Development Fund (Refs: BFU2009-09537, BFU2012-34838), by the foundation “La Marató de TV3” (Ref: 091430), by the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneix...
Article
Full-text available
The regulation of cognitive and emotional processes is critical for proper executive functions and social behavior, but its specific mechanisms remain unknown. Here, we addressed this issue by studying with functional magnetic resonance imaging the changes in network topology that underlie competitive interactions between emotional and cognitive ne...
Chapter
Cognitive processes are altered in depression patients, and their neuromodulation by serotonergic treatments may depend on the specific pathophysiology of the disease. Here, we addressed this question in a computational model that included two mutually inhibiting network hubs in the ventral anterior cingulate cortex (vACC) and dorsolateral prefront...
Data
U and D period durations and statistics for individual experiments.
Data
Instantaneous population rate averaged across transitions RDU(τ) and RUD(τ) for individual experiments.
Article
Full-text available
In the idling brain, neuronal circuits transition between periods of sustained firing (UP state) and quiescence (DOWN state), a pattern the mechanisms of which remain unclear. Here we analyzed spontaneous cortical population activity from anesthetized rats and found that UP and DOWN durations were highly variable and that population rates showed no...
Preprint
Full-text available
The regulation of cognitive and emotional processes is critical for proper executive functions and social behavior, but its specific mechanisms remain unknown. Here, we addressed this issue by studying with functional magnetic resonance imaging the changes in network topology that underlie competitive interactions between emotional and cognitive ne...
Article
The emergent dynamics in networks of recurrently coupled spiking neurons depends on the interplay between single-cell dynamics and network topology. Most theoretical studies on network dynamics have assumed simple topologies, such as connections that are made randomly and independently with a fixed probability (Erdös-Rényi network) (ER) or all-to-a...
Preprint
Full-text available
The emergent dynamics in networks of recurrently coupled spiking neurons depends on the interplay between single-cell dynamics and network topology. Most theoretical studies on network dynamics have assumed simple topologies, such as connections which are made randomly and independently with a fixed probability (Erdös-Rényi network) (ER), or all-to...
Preprint
In the idling brain, neuronal circuits often exhibit transitions between periods of sustained firing (UP state) and quiescence (DOWN state). Although these dynamics occur across multiple areas and behavioral conditions, the underlying mechanisms remain unclear. Here we analyze spontaneous population activity from the somatosensory cortex of urethan...
Article
Bistability between attracting fixed points in neuronal networks has been hypothesized to underlie persistent activity observed in several cortical areas during working memory tasks. In network models this kind of bistability arises due to strong recurrent excitation, sufficient to generate a state of high activity created in a saddle-node (SN) bif...
Article
Neuronal activity in the lateral prefrontal cortex (LPFC) reflects the structure and cognitive demands of memory-guided sensory discrimination tasks. However, we still do not know how neuronal activity articulates in network states involved in perceiving, remembering, and comparing sensory information during such tasks. Oscillations in local field...
Chapter
Candidate mechanisms of brain function can potentially be identified using biologically detailed computational models. A critical question that arises from the construction and analysis of such models is whether a particular set of parameters is unique or whether multiple different solutions exist, each capable of reproducing some relevant phenomen...
Article
Full-text available
Major depression disease (MDD) is associated with the dysfunction of multinode brain networks. However, converging evidence implicates the reciprocal interaction between midline limbic regions (typified by the ventral anterior cingulate cortex, vACC) and the dorso-lateral prefrontal cortex (dlPFC), reflecting interactions between emotions and cogni...
Article
Binding errors, also called swap errors, occur in working memory tasks when the participant fails to report the feature of a previously presented target but the response is accurate relative to a non-target stimulus (for instance, s/he reports the location of the green item when the red item’s location was to be reported). Psychophysical experiment...
Article
Full-text available
The amount of information that can be retained in working-memory (WM) is limited. Limitations of WM capacity have been the subject of intense research, especially trying to specify algorithmic models for WM. Comparatively, neural circuit perspectives have barely been used to test WM limitations in behavioral experiments. Here, we used a neuronal mi...
Article
Full-text available
Neuronal variability in sensory cortex predicts perceptual decisions. This relationship, termed choice probability (CP), can arise from sensory variability biasing behaviour and from top-down signals reflecting behaviour. To investigate the interaction of these mechanisms during the decision-making process, we use a hierarchical network model compo...
Article
Prefrontal persistent activity during the delay of spatial working memory tasks is thought to maintain spatial location in memory. A 'bump attractor' computational model can account for this physiology and its relationship to behavior. However, direct experimental evidence linking parameters of prefrontal firing to the memory report in individual t...
Article
Full-text available
Serotonin (5-HT) receptors of types 1A and 2A are strongly expressed in prefrontal cortex (PFC) neurons, an area associated with cognitive function. Hence, 5-HT could be effective in modulating prefrontal-dependent cognitive functions, such as spatial working memory (SWM). However, a direct association between 5-HT and SWM has proved elusive in psy...
Article
Full-text available
Limitations in the performance of working memory (WM) tasks have been characterized in terms of the number of items retained (capacity) and in terms of the precision with which the information is retained. The neural mechanisms behind these limitations are still unclear. Here we used a biological constrained computational model to study the capacit...
Article
Full-text available
The prefrontal cortex (PFC) contains a dense network of serotonergic [serotonin, 5-hydroxytryptamine (5-HT)] axons, and endogenous 5-HT markedly modulates PFC neuronal function via several postsynaptic receptors. The therapeutic action of atypical antipsychotic drugs, acting mainly via 5-HT receptors, also suggests a role for serotonergic neurotran...
Article
Cognitive deficits in schizophrenia have been hypothesized to be caused by altered synaptic transmission in circuits of the prefrontal cortex. 2 main hypotheses have been put forward: reduced inhibition and hypofunctional NMDA receptors. Recently, Lee et al. (2008) found that spatial working memory deficits in schizophrenic patients include a dispr...
Article
Full-text available
We use the recently developed framework of second order networks[1] to study the influence of network topology on synchrony and oscillations in networks of integrate-and-fire neurons. Second order networks are generalizations of Erdős–Renyi random networks [2], where one can specify the second order statistics among the network connections, i.e., t...
Article
Full-text available
A putative neuronal correlate of working-memory (WM) is the so called persistent or delay activity, that is the stimulus selective elevated neuronal firing observed long after stimulus offset. Neuronal activity with these characteristics has been found in several cortical areas in association with the performance of visuo-spatial working-memory (vs...
Article
Full-text available
Mathematical models are increasingly used in life sciences. However, contrary to other disciplines, biological models are typically over-parametrized and loosely constrained by scarce experimental data and prior knowledge. Recent efforts on analysis of complex models have focused on isolated aspects without considering an integrated approach-rangin...
Article
Full-text available
The balance between excitation and inhibition is critical in the physiology of the cerebral cortex. To understand the influence of inhibitory control on the emergent activity of the cortical network, inhibition was progressively blocked in a slice preparation that generates spontaneous rhythmic up states at a similar frequency to those occurring in...
Data
Model equations. (0.16 MB DOC)
Article
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Author Summary The basic computational principles of the brain are still unknown, and one major reason for this is related to the difficulties in simultaneously measuring detailed data from a sufficiently large number of cells. In techniques where populations of cells are monitored, resolution is low. Computational models have no such measurement l...
Article
Full-text available
In the local cortical network, spontaneous emergent activity self-organizes in rhythmic patterns. These rhythms include a slow one (<1 Hz), consisting in alternation of up and down states, and also faster rhythms (10-80 Hz) generated during up states. Varying the temperature in the bath between 26 and 41 degrees C resulted in a strong modulation of...
Article
Full-text available
In this computational work, we investigated gamma-band synchronization across cortical circuits associated with selective attention. The model explicitly instantiates a reciprocally connected loop of spiking neurons between a sensory-type (area MT) and an executive-type (prefrontal/parietal) cortical circuit (the source area for top-down attentiona...
Article
Integration of information across time is a neural computation of critical importance to a variety of brain functions. Examples include oculomotor neural integrators and head direction cells that integrate velocity signals into positional or directional signals, parametric working memory circuits which convert transient input pulses into self-susta...
Chapter
Full-text available
The interaction between excitation and inhibition in the cerebral cortex network determines the emergent patterns of activity. Here we analyze the specific engagement of excitation and inhibition during a physiological network function such as slow oscillatory activity ( < 1 Hz), during which up and down cortical states alternate. This slow rhythm...
Article
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