350 results on '"Cisek, Paul"'
Search Results
102. The modulatory influence of end-point controllability on decisions between actions
- Author
-
Cos, Ignasi, primary, Medleg, Farid, additional, and Cisek, Paul, additional
- Published
- 2012
- Full Text
- View/download PDF
103. From anticipation to action, the role of dopamine in perceptual decision making: an fMRI-tyrosine depletion study
- Author
-
Nagano-Saito, Atsuko, primary, Cisek, Paul, additional, Perna, Andrea S., additional, Shirdel, Fatemeh Z., additional, Benkelfat, Chawki, additional, Leyton, Marco, additional, and Dagher, Alain, additional
- Published
- 2012
- Full Text
- View/download PDF
104. Dorsal premotor cortex is involved in switching motor plans
- Author
-
Pastor-Bernier, Alexandre, primary, Tremblay, Elsa, additional, and Cisek, Paul, additional
- Published
- 2012
- Full Text
- View/download PDF
105. The influence of predicted arm biomechanics on decision making
- Author
-
Cos, Ignasi, primary, Bélanger, Nicolas, additional, and Cisek, Paul, additional
- Published
- 2011
- Full Text
- View/download PDF
106. Making Choices between Rules or between Actions
- Author
-
Pastor-Bernier, Alexandre, primary and Cisek, Paul, additional
- Published
- 2011
- Full Text
- View/download PDF
107. Spiking neurons that keep the rhythm
- Author
-
Thivierge, Jean-Philippe, primary and Cisek, Paul, additional
- Published
- 2010
- Full Text
- View/download PDF
108. Response Competition in the Primary Motor Cortex: Corticospinal Excitability Reflects Response Replacement During Simple Decisions
- Author
-
Michelet, Thomas, primary, Duncan, Gary H., additional, and Cisek, Paul, additional
- Published
- 2010
- Full Text
- View/download PDF
109. Decisions in Changing Conditions: The Urgency-Gating Model
- Author
-
Cisek, Paul, primary, Puskas, Geneviève Aude, additional, and El-Murr, Stephany, additional
- Published
- 2009
- Full Text
- View/download PDF
110. Nonperiodic Synchronization in Heterogeneous Networks of Spiking Neurons
- Author
-
Thivierge, Jean-Philippe, primary and Cisek, Paul, additional
- Published
- 2008
- Full Text
- View/download PDF
111. A Remarkable Facilitating Effect of Parietal Damage
- Author
-
Cisek, Paul, primary
- Published
- 2008
- Full Text
- View/download PDF
112. Cortical Control of Whole‐Arm Motor Tasks
- Author
-
Kalaska, John F., primary, Sergio, Lauren E., additional, and Cisek, Paul, additional
- Published
- 2007
- Full Text
- View/download PDF
113. Endovascular Repair of a Secondary Aortoesophageal Fistula: a Case Report and Review of the Literature
- Author
-
Taylor, Benedict J.W., primary, Stewart, David, additional, West, Phillip, additional, Dunn, James T., additional, and Cisek, Paul, additional
- Published
- 2007
- Full Text
- View/download PDF
114. Ruptured Abdominal Aortic Aneurysm: Does Trauma Center Designation Affect Outcome?
- Author
-
Bounoua, Farida, primary, Schuster, Rob, additional, Grewal, Prabhjot, additional, Waxman, Kenneth, additional, and Cisek, Paul, additional
- Published
- 2007
- Full Text
- View/download PDF
115. Preparing for Speed. Focus on “Preparatory Activity in Premotor and Motor Cortex Reflects the Speed of the Upcoming Reach”
- Author
-
Cisek, Paul, primary
- Published
- 2006
- Full Text
- View/download PDF
116. Integrated Neural Processes for Defining Potential Actions and Deciding between Them: A Computational Model
- Author
-
Cisek, Paul, primary
- Published
- 2006
- Full Text
- View/download PDF
117. Neural Correlates of Reaching Decisions in Dorsal Premotor Cortex: Specification of Multiple Direction Choices and Final Selection of Action
- Author
-
Cisek, Paul, primary and Kalaska, John F., additional
- Published
- 2005
- Full Text
- View/download PDF
118. Kinematics and Kinetics of Multijoint Reaching in Nonhuman Primates
- Author
-
Graham, Kirsten M., primary, Moore, Kimberly D., additional, Cabel, D. William, additional, Gribble, Paul L., additional, Cisek, Paul, additional, and Scott, Stephen H., additional
- Published
- 2003
- Full Text
- View/download PDF
119. Neural Activity in Primary Motor and Dorsal Premotor Cortex In Reaching Tasks With the Contralateral Versus Ipsilateral Arm
- Author
-
Cisek, Paul, primary, Crammond, Donald J., additional, and Kalaska, John F., additional
- Published
- 2003
- Full Text
- View/download PDF
120. Modest Gaze-Related Discharge Modulation in Monkey Dorsal Premotor Cortex During a Reaching Task Performed With Free Fixation
- Author
-
Cisek, Paul, primary and Kalaska, John F., additional
- Published
- 2002
- Full Text
- View/download PDF
121. Simultaneous Encoding of Multiple Potential Reach Directions in Dorsal Premotor Cortex
- Author
-
Cisek, Paul, primary and Kalaska, John F., additional
- Published
- 2002
- Full Text
- View/download PDF
122. Neural Activity in Primary Motor Cortex Related to Mechanical Loads Applied to the Shoulder and Elbow During a Postural Task
- Author
-
Cabel, D. William, primary, Cisek, Paul, additional, and Scott, Stephen H., additional
- Published
- 2001
- Full Text
- View/download PDF
123. An alternative interpretation of population vector rotation in macaque motor cortex
- Author
-
Cisek, Paul, primary and Scott, Stephen H, additional
- Published
- 1999
- Full Text
- View/download PDF
124. Cortical control of reaching movements
- Author
-
Kalaska, John F, primary, Scott, Stephen H, additional, Cisek, Paul, additional, and Sergio, Lauren E, additional
- Published
- 1997
- Full Text
- View/download PDF
125. Operative Repair of Enlarging Hilar Renal Artery Aneurysm
- Author
-
Eze, Augustine R., primary, Singh, Sunnanda, additional, Newman, Paul G., additional, Cisek, Paul L., additional, and Comerota, Anthony J., additional
- Published
- 1997
- Full Text
- View/download PDF
126. Descending Corticospinal Control of Intersegmental.
- Author
-
Gritsenko, Valeriya, Kalaska, John F., and Cisek, Paul
- Subjects
PYRAMIDAL tract ,MOTOR cortex ,CENTRAL nervous system ,MOTOR ability ,TRANSCRANIAL magnetic stimulation ,ELBOW ,JOINTS (Anatomy) - Abstract
To make an accurate movement, the CNS has to overcome the inherent complexities of the multijoint limb. For example, interaction torques arise when motion of individual arm segments propagates to adjacent segments causing their movement without any muscle contractions. Since these passive joint torques significantly add to the overall torques generated by active muscular contractions, they must be taken into account during planning or execution of goal-directed movements. We investigated the role of the corticospinal tract in compensating for the interaction torques during arm movements in humans. Twelve subjects reached to visual targets with their arm supported by a robotic exoskeleton. Reaching to one target was accompanied by interaction torques that assisted the movement, while reaching to the other target was accompanied by interaction torques that resisted the movement. Corticospinal excitability was assessed at different times during movement using single-pulse transcranial magnetic stimulation (TMS) over the upper-arm region of M1 (primary motor cortex). We found that TMS responses in shoulder monoarticular and elbow-shoulder biarticular muscles changed together with the interaction torques during movements in which the interaction torques were resistive. In contrast, TMS responses did not correlate with assistive interaction torques or with co-contraction. This suggests that the descending motor command includes compensation for passive limb dynamics. Furthermore, our results suggest that compensation for interaction torques involves the biarticular muscles, which span both shoulder and elbow joints and are in a biomechanically advantageous position to provide such compensation. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
127. Neural Correlates of Biased Competition in Premotor Cortex.
- Author
-
Pastor-Bernier, Alexandre and Cisek, Paul
- Subjects
- *
NEURONS , *CELLS , *NERVOUS system , *SENSORIMOTOR cortex , *CEREBRAL cortex - Abstract
It has been proposed that whenever an animal faces several action choices, their neural representations are processed in parallel in frontoparietal cortex and compete in a manner biased by any factor relevant to the decision. We tested this hypothesis by recording single-unit activity in dorsal premotor cortex (PMd) while a monkey performed two delayed center-out reaching tasks. In the one-target task, a single target was presented and its border style indicated its reward value. The two-target task was the same except two targets were presented and the value of each was varied. During the delay period of the one-target task, directionally tuned PMd activity showed no modulation with value. In contrast, during the two-target task, the same neurons showed strong effects of the value associated with their preferred target, always in relation to the value of the other target. Furthermore, the competition between action choices was strongest when targets were furthest apart. This angular distance effect appeared in neural activity as soon as cells became tuned, while modulation by relative value appeared much later. All of these findings can be reproduced by a computational model which suggests that decisions between actions are made through a biased competition taking place within a sensorimotor map of potential actions. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
128. High Field Nb[sub 3] Sn Conductor Development at Oxford Superconducting Technology.
- Author
-
Parrell, Jeffrey A., Youzhu Zhang, Field, Michael B., Cisek, Paul, and Seung Hong
- Subjects
SUPERCONDUCTORS ,NIOBIUM alloys - Abstract
Oxford Instruments, Superconducting Technology (OI-ST) produces Nb[sub 3]Sn wire via several "internal Sn" routes. Recently, 12 T, 4.2 K non-Cu critical current density (J[sub c]) values of ∼2900 A/mm² have been achieved by increasing the Nb and Sn fractions of the filament subelements. Similar conductors for high field use have shown engineering current density (J[sub e]) values of 170 A/mm² at 23.5 T, 1.8 K. OI-ST is also involved with research for the High Energy Physics (HEP) National Conductor Program. Results on composites made entirely by hot extrusion are described. Finally, the present status of Ta-Sn powder-in-tube (PIT) and Nb[sub 3]Al precursor strand development are presented. PIT strands have irreversibility fields over 26 T at 4.2 K, while Nb[sub 3]Al precursor strand has been produced by a route that promotes bonding of the billet components. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
129. Operative Repair of Enlarging Hilar Renal Artery Aneurysm.
- Author
-
Eze, Augustine R., Singh, Sunnanda, Newman, Paul G., Cisek, Paul L., and Comerota, Anthony J.
- Abstract
Repair of distal renal artery aneurysms poses a significant threat to kidney salvage despite improved operative techniques described over the past decades. The authors describe the case of a seventy-one-year-old woman who presented with an enlarging right renal artery aneurysm located at the renal hilum involving the lobar arteries. Operative repair was accomplished by excision of the saccular posterior wall and reconstruction with a saphenous vein patch. The ischemia time was thirty-three minutes and her postoperative course was uneventful. She was discharged home on the fifth postoperative day with normal renal function, and the renal arteriogram demonstrated a technically successful operation. They review the current literature, and this case is put into perspective with the natural history, clinical course, and present treatment of renal artery aneurysms. [ABSTRACT FROM PUBLISHER]
- Published
- 1997
- Full Text
- View/download PDF
130. Hasty sensorimotor decisions rely on an overlap of broad and selective changes in motor activity.
- Author
-
Derosiere, Gerard, Thura, David, Cisek, Paul, and Duque, Julie
- Subjects
- *
FINGERS , *TRANSCRANIAL magnetic stimulation , *EVOKED potentials (Electrophysiology) , *LEG muscles , *SIGNAL-to-noise ratio - Abstract
Humans and other animals are able to adjust their speed–accuracy trade-off (SAT) at will depending on the urge to act, favoring either cautious or hasty decision policies in different contexts. An emerging view is that SAT regulation relies on influences exerting broad changes on the motor system, tuning its activity up globally when hastiness is at premium. The present study aimed to test this hypothesis. A total of 50 participants performed a task involving choices between left and right index fingers, in which incorrect choices led either to a high or to a low penalty in 2 contexts, inciting them to emphasize either cautious or hasty policies. We applied transcranial magnetic stimulation (TMS) on multiple motor representations, eliciting motor-evoked potentials (MEPs) in 9 finger and leg muscles. MEP amplitudes allowed us to probe activity changes in the corresponding finger and leg representations, while participants were deliberating about which index to choose. Our data indicate that hastiness entails a broad amplification of motor activity, although this amplification was limited to the chosen side. On top of this effect, we identified a local suppression of motor activity, surrounding the chosen index representation. Hence, a decision policy favoring speed over accuracy appears to rely on overlapping processes producing a broad (but not global) amplification and a surround suppression of motor activity. The latter effect may help to increase the signal-to-noise ratio of the chosen representation, as supported by single-trial correlation analyses indicating a stronger differentiation of activity changes in finger representations in the hasty context. Many have argued that the regulation of the speed-accuracy tradeoff relies on an urgency signal, which implements "collapsing decision thresholds" by tuning neural activity in a global manner in decision-related structures. This study indicates that the reality is more subtle, with several aspects of "urgency" being specifically targeted to particular corticospinal populations within the motor system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
131. Regioselective reaction of thiols with catechol estrogens and estrogen-O-quinones
- Author
-
Abul-Hajj, Yusuf J., primary and Cisek, Paul L., additional
- Published
- 1986
- Full Text
- View/download PDF
132. Catechol estrogen adducts
- Author
-
Abul-Hajj, Yusuf J., primary and Cisek, Paul L., additional
- Published
- 1988
- Full Text
- View/download PDF
133. No one knows what attention is.
- Author
-
Hommel, Bernhard, Chapman, Craig S., Cisek, Paul, Neyedli, Heather F., Song, Joo-Hyun, and Welsh, Timothy N.
- Subjects
- *
SELECTIVITY (Psychology) , *ATTENTION , *SUPERIOR colliculus - Abstract
In this article, we challenge the usefulness of "attention" as a unitary construct and/or neural system. We point out that the concept has too many meanings to justify a single term, and that "attention" is used to refer to both the explanandum (the set of phenomena in need of explanation) and the explanans (the set of processes doing the explaining). To illustrate these points, we focus our discussion on visual selective attention. It is argued that selectivity in processing has emerged through evolution as a design feature of a complex multi-channel sensorimotor system, which generates selective phenomena of "attention" as one of many by-products. Instead of the traditional analytic approach to attention, we suggest a synthetic approach that starts with well-understood mechanisms that do not need to be dedicated to attention, and yet account for the selectivity phenomena under investigation. We conclude that what would serve scientific progress best would be to drop the term "attention" as a label for a specific functional or neural system and instead focus on behaviorally relevant selection processes and the many systems that implement them. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
134. Integrated neural dynamics of sensorimotor decisions and actions.
- Author
-
Thura, David, Cabana, Jean-François, Feghaly, Albert, and Cisek, Paul
- Subjects
- *
PREMOTOR cortex , *DYNAMICAL systems , *GLOBUS pallidus , *PREFRONTAL cortex , *DELIBERATION - Abstract
Recent theoretical models suggest that deciding about actions and executing them are not implemented by completely distinct neural mechanisms but are instead two modes of an integrated dynamical system. Here, we investigate this proposal by examining how neural activity unfolds during a dynamic decision-making task within the high-dimensional space defined by the activity of cells in monkey dorsal premotor (PMd), primary motor (M1), and dorsolateral prefrontal cortex (dlPFC) as well as the external and internal segments of the globus pallidus (GPe, GPi). Dimensionality reduction shows that the four strongest components of neural activity are functionally interpretable, reflecting a state transition between deliberation and commitment, the transformation of sensory evidence into a choice, and the baseline and slope of the rising urgency to decide. Analysis of the contribution of each population to these components shows meaningful differences between regions but no distinct clusters within each region, consistent with an integrated dynamical system. During deliberation, cortical activity unfolds on a two-dimensional "decision manifold" defined by sensory evidence and urgency and falls off this manifold at the moment of commitment into a choice-dependent trajectory leading to movement initiation. The structure of the manifold varies between regions: In PMd, it is curved; in M1, it is nearly perfectly flat; and in dlPFC, it is almost entirely confined to the sensory evidence dimension. In contrast, pallidal activity during deliberation is primarily defined by urgency. We suggest that these findings reveal the distinct functional contributions of different brain regions to an integrated dynamical system governing action selection and execution. Recent theoretical models suggest that deciding about actions and executing them are not mediated by completely distinct neural mechanisms but are instead two modes of a single system. Analysis of neural activity in several cortical and subcortical regions reveals how they implement an integrated dynamical system that governs deliberation, selection, and execution of actions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
135. The urgency-gating model can explain the effects of early evidence.
- Author
-
Carland, Matthew, Thura, David, and Cisek, Paul
- Subjects
- *
DECISION making , *DIFFERENTIATION (Cognition) , *REACTION time , *RANDOM noise theory , *STANDARD deviations - Abstract
In a recent report, Winkel, Keuken, van Maanen, Wagenmakers & Forstmann ( Psychonomics Bulletin and Review 21(3): 777-784, ) show that during a random-dot motion discrimination task, early differences in motion evidence can influence reaction times (RTs) and error rates in human subjects. They use this as an argument in favor of the drift-diffusion model and against the urgency-gating model. However, their implementation of the urgency-gating model is incomplete, as it lacks the low-pass filter that is necessary to deal with noisy input such as the motion signal used in their experimental task. Furthermore, by focusing analyses solely on comparison of mean RTs they overestimate how long early information influences individual trials. Here, we show that if the urgency-gating model is correctly implemented, including a low-pass filter with a 250 ms time constant, it can successfully reproduce the results of the Winkel et al. experiment. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
136. The road towards understanding embodied decisions.
- Author
-
Gordon, Jeremy, Maselli, Antonella, Lancia, Gian Luca, Thiery, Thomas, Cisek, Paul, and Pezzulo, Giovanni
- Subjects
- *
SPORTS psychology , *GAZELLES , *DECISION making , *EXPERIMENTAL psychology - Abstract
• We continuously face "embodied decisions" between action possibilities or affordances. • Given their complexity, embodied decisions have been challenging to study so far. • We review novel ways to study embodied decisions in sports analytics and psychology. • We advance a novel method to formalize embodied decision variables rigorously. • Studying embodied decisions can shed light on how we make decisions "in the wild". Most current decision-making research focuses on classical economic scenarios, where choice offers are prespecified and where action dynamics play no role in the decision. However, our brains evolved to deal with different choice situations: "embodied decisions". As examples of embodied decisions, consider a lion that has to decide which gazelle to chase in the savannah or a person who has to select the next stone to jump on when crossing a river. Embodied decision settings raise novel questions, such as how people select from time-varying choice options and how they track the most relevant choice attributes; but they have long remained challenging to study empirically. Here, we summarize recent progress in the study of embodied decisions in sports analytics and experimental psychology. Furthermore, we introduce a formal methodology to identify the relevant dimensions of embodied choices (present and future affordances) and to map them into the attributes of classical economic decisions (probabilities and utilities), hence aligning them. Studying embodied decisions will greatly expand our understanding of what decision-making is. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
137. Potentiels de champ locaux lors d'une prise de décision à plusieurs facteurs
- Author
-
Lusignan, Thomas and Cisek, Paul
- Subjects
Primates ,Potentiels de champ locaux ,Prise de décision ,Mouvements d’atteinte ,Posterior Parietal Cortex ,Local Field Potentials ,Cortex pariétal postérieur ,Cortex prémoteur dorsal ,Reaching Movements ,Decision-making ,Dorsal Premotor Cortex - Abstract
Choisir quel mouvement effectuer est une fonction primordiale du système nerveux central. Comment ces décisions sont prises est encore sujet à débats. Une hypothèse traditionnelle pose qu’elles sont prises de façon sérielle, à l’aide de processus perceptifs qui alimentent un exécutif central, qui communique ensuite au système moteur quel mouvement effectuer. L’hypothèse alternative préférée par notre équipe est que les mouvements potentiels commencent à être préparés en parallèle et entrent en compétition pour les effecteurs. Dans le but de tester ces hypothèses, notre équipe a enseigné à un macaque une tâche de prise de décision motrice. Le sujet y est placé devant un écran où deux cibles apparaissent. Chacune a une valeur qui découle de deux caractéristiques : sa luminosité (BU pour bottom-up, information ascendante) et l’orientation d’une ligne qui la coupe comme une aiguille d’horloge (TD pour top-down, information descendante.) Le sujet choisit une des deux à l’aide d’un mouvement d’atteinte, et reçoit une récompense proportionnelle à sa valeur. Cette tâche permet de comparer plusieurs types d’essais : certains présentent une seule cible, une absence de choix, ou deux cibles identiques, un choix sans conséquence. D’autres ont une cible plus valable que l’autre, le choix est alors facile. On peut alors faire varier la caractéristique (BU ou TD) qui donne une plus grande valeur à la meilleure cible. Finalement, on peut montrer deux cibles de valeur égale, mais dont une tire sa valeur d’un bon score TD et l’autre, d’un bon score BU. Le sujet doit alors, en quelque sorte, choisir entre les caractéristiques. Pendant que le sujet exécute la tâche, on enregistre ses potentiels de champ locaux (LFP) à l’aide de deux réseaux d’électrodes déplaçables individuellement, l’un placé dans le cortex pariétal postérieur (PPC) et l’autre, dans le cortex prémoteur dorsal (PMd). L’analyse de ces données à l’aide de spectrogrammes, et une discussion des réactions spécifiques dans les bandes de fréquences alpha, bêta et gamma, sont présentées ici., Choosing which movement to make is a primary function of the central nervous system. How these decisions are made is still a matter of debate. A traditional hypothesis posits that such decisions are made in a serial fashion: perceptual processes feed into a central executive, which then communicates to the motor system which movement to make. The alternative hypothesis preferred by our team is that potential movements begin to be prepared in parallel, and compete for effectors until a consensus forms in brain areas related to controlling the movements. In order to test these hypotheses, our team taught a macaque to perform a reach-based decision-making task. The subject is placed in front of a screen on which two targets appear. Each target has a value derived from two features: its brightness (BU, bottom-up information) and the orientation of a line that crosses it like a clock hand (TD, top-down information.) The subject freely chooses one of the two targets by reaching it, and then receives a reward proportional to its value. This task compares several types of trials: some show a single target, therefore no choice, or show two identical targets, which means the choice has no consequences. Other trials have one target that is more valuable than the other, which makes the choice easy. The feature which gives that better target a greater value can be either BU or TD. Finally, some trials show two targets of equal value, but one of them derives its value from a good TD score while the other derives its value from a good BU score. The subject must then choose between the features. While the subject performs the task, local field potentials (LFP) are recorded using two individually movable electrode arrays. One array is placed in the posterior parietal cortex (PPC) and the other, in the dorsal premotor cortex (PMd). The data thus obtained is analyzed using spectrograms, and a discussion of specific responses in the alpha, beta, and gamma frequency bands is presented here.
- Published
- 2022
138. An investigation of reach decisions during ongoing action control
- Author
-
Michalski, Julien, Cisek, Paul, and Green, Andrea M.
- Subjects
modèle de diffusion ,Embodied decision ,modèle neuro-économique ,Biomécanique ,Reaching ,prise de décision ,Neuroeconomics ,décision incarnée ,Affordance competition hypothesis ,Drift-diffusion model ,Motor control ,décision perceptuelle ,mouvement d’atteinte ,Biomechanics ,Perceptual decision ,contrôle moteur ,Decision-making - Abstract
Les études neurophysiologiques de la prise de décision, traditionnellement ancrées dans des principes neuro-économiques, ont évoluées pour inclure une variété d’aires du cerveau. Partant d’abord du lobe frontal associé aux jugements de valeur, le champ s’est élargi pour inclure d’autres types de décisions incluant les décisions perceptuelles et les décisions incarnées qui impliquent notamment les aires sensorimotrices du cerveau. La théorie moderne de la prise de décision modèle l’activité neurale dans ces régions comme une compétition entre les différents stimuli et actions considérés par un individu. Cette compétition est résolue lorsque l’activité neurale associée à un stimulus ou une action choisie atteint un seuil critique. Toutefois, il reste à éclaircir comment ce modèle s’applique aux décisions effectuées alors que l’individu est déjà engagé dans une activité. Dans ce mémoire nous examinons ce type de décision chez des sujets humains dans une tâche de suivi continu. Des cibles « choix » apparaissaient sur un écran pendant que le sujet suivait de la main une cible qui se déplaçait doucement en continu. Le sujet pouvait ignorer ces cibles choix, ou abandonner la cible suivie pour toucher une cible choix, dans quel cas la cible sélectionnée devenait la nouvelle cible à suivre du doigt. Tel qu’attendu, nous avons observé que les sujets favorisaient les cibles plus proches, plus grandes, et les cibles alignées avec l’axe du mouvement. Toutefois nous avons été surpris de constater que les sujets ignoraient les coûts énergétiques du mouvement, tel que modélisés. Un biais pour minimiser les coûts du mouvement fut réintroduis lorsque la tâche fut divisée en séries de mouvements point-à-point, plutôt qu’un mouvement continu. Même si nous ne pouvons expliquer ce résultat surprenant, nous espérons qu’il inspire de futures études utilisant le paradigme expérimental de décision durant l’action., Neurophysiological studies of decision-making have expanded over decades to involve many brain areas. The field broadened from neuroeconomics, mainly concerned with frontal regions, to perceptual or embodied decision-making involving several sensorimotor areas where neural activity is linked to the stimuli and actions necessary for the decision process. Current models of decision-making envision this neural activity as a competition between different actions that is resolved when enough activity favors one over the other. However, it is unclear how such models can explain decisions often present in natural behavior, where deliberation takes place while already engaged in an action. In this thesis, we examined the choices human subjects made as they were engaged in a continuous tracking task. While they were manually tracking a target on a flat screen, subjects were occasionally presented with a new target to which they could freely choose to switch, whereupon it became the new tracked target. As expected, we found that subjects were more likely to move to closer targets, bigger targets, or targets that were aligned to the direction of movement. However, we were surprised that subjects did not choose targets that minimized energetic cost, as calculated by a biomechanical model of the arm. A biomechanical bias was restored when the continuous movement was broken up into a series of point to point movements. While we cannot yet explain these findings with certainty, we hope they will inspire further studies using decide-while-acting paradigms.
- Published
- 2021
139. Shared population-level dynamics in monkey premotor cortex during solo action, joint action and action observation.
- Author
-
Pezzulo, Giovanni, Donnarumma, Francesco, Ferrari-Toniolo, Simone, Cisek, Paul, and Battaglia-Mayer, Alexandra
- Subjects
- *
PREMOTOR cortex , *VISUOMOTOR coordination , *MONKEYS , *POPULATION dynamics - Abstract
• In PMd neural dynamics is shared across action execution and mere observation. • Task directional features are more accurately discriminated than action types. • Spatial aspects are encoded in PMd independently from specific behavioral demands. • PMd dynamics largely reflect higher cognitive-motor processes rather than strictly motor-related functions. Studies of neural population dynamics of cell activity from monkey motor areas during reaching show that it mostly represents the generation and timing of motor behavior. We compared neural dynamics in dorsal premotor cortex (PMd) during the performance of a visuomotor task executed individually or cooperatively and during an observation task. In the visuomotor conditions, monkeys applied isometric forces on a joystick to guide a visual cursor in different directions, either alone or jointly with a conspecific. In the observation condition, they observed the cursor's motion guided by the partner. We found that in PMd neural dynamics were widely shared across action execution and observation, with cursor motion directions more accurately discriminated than task types. This suggests that PMd encodes spatial aspects irrespective of specific behavioral demands. Furthermore, our results suggest that largest components of premotor population dynamics, which have previously been suggested to reflect a transformation from planning to movement execution, may rather reflect higher cognitive-motor processes, such as the covert representation of actions and goals shared across tasks that require movement and those that do not. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
140. A theoretical and experimental dissociation of two models of decision‐making
- Author
-
Carland, Matthew A. and Cisek, Paul
- Subjects
Urgency-gating model ,Sequential sampling ,Modèle d'urgence ,Prise de décision ,Test d'hypothèses ,Neuroéconomie ,Modèle de diffusion ,Neuroeconomics ,Random dot motion ,Drift-diffusion model ,Speed-accuracy trade-off ,Taux de récompense ,Perceptual discrimination ,Echantillonnage séquentiel ,Hypothesis-testing ,Reward rate ,Compromis vitesse/précision ,Mouvement aléatoire de points ,Decision-making ,Discrimination perceptuelle - Abstract
La prise de décision est un processus computationnel fondamental dans de nombreux aspects du comportement animal. Le modèle le plus souvent rencontré dans les études portant sur la prise de décision est appelé modèle de diffusion. Depuis longtemps, il explique une grande variété de données comportementales et neurophysiologiques dans ce domaine. Cependant, un autre modèle, le modèle d’urgence, explique tout aussi bien ces mêmes données et ce de façon parcimonieuse et davantage encrée sur la théorie. Dans ce travail, nous aborderons tout d’abord les origines et le développement du modèle de diffusion et nous verrons comment il a été établi en tant que cadre de travail pour l’interprétation de la plupart des données expérimentales liées à la prise de décision. Ce faisant, nous relèveront ses points forts afin de le comparer ensuite de manière objective et rigoureuse à des modèles alternatifs. Nous réexaminerons un nombre d’assomptions implicites et explicites faites par ce modèle et nous mettrons alors l’accent sur certains de ses défauts. Cette analyse servira de cadre à notre introduction et notre discussion du modèle d’urgence. Enfin, nous présenterons une expérience dont la méthodologie permet de dissocier les deux modèles, et dont les résultats illustrent les limites empiriques et théoriques du modèle de diffusion et démontrent en revanche clairement la validité du modèle d'urgence. Nous terminerons en discutant l'apport potentiel du modèle d'urgence pour l'étude de certaines pathologies cérébrales, en mettant l'accent sur de nouvelles perspectives de recherche., Decision‐making is a computational process of fundamental importance to many aspects of animal behavior. The prevailing model in the experimental study of decision‐making is the drift‐diffusion model, which has a long history and accounts for a broad range of behavioral and neurophysiological data. However, an alternative model – called the urgency‐gating model – has been offered which can account equally well for much of the same data in a more parsimonious and theoretically‐sound manner. In what follows, we will first trace the origins and development of the DDM, as well as give a brief overview of the manner in which it has supplied an explanatory framework for a large number of behavioral and physiological studies in the domain of decision‐making. In so doing, we will attempt to build a strong and clear case for its strengths so that it can be fairly and rigorously compared to potential alternative models. We will then re‐examine a number of the implicit and explicit theoretical assumptions made by the drift‐diffusion model, as well as highlight some of its empirical shortcomings. This analysis will serve as the contextual backdrop for our introduction and discussion of the urgency‐gating model. Finally, we present a novel experiment, the methodological design of which uniquely affords a decisive empirical dissociation of the models, the results of which illustrate the empirical and theoretical shortcomings of the drift‐diffusion model and instead offer clear support for the urgency‐gating model. We finish by discussing the potential for the urgency gating model to shed light on a number of clinical disorders, highlighting a number of future directions for research.
- Published
- 2015
141. Neural correlates of affordance competition in dorsal premotor cortex
- Author
-
Pastor Bernier, Alexandre and Cisek, Paul
- Subjects
Competition ,Action selection ,Premotor cortex ,Distance ,Decision ,Spatial parameters ,Action specification ,Relative value ,Affordance ,Electrophysiology ,Bias ,PMv ,Absolute value ,Electrophysiologie ,PMd ,Decisions - Abstract
Le travail présenté dans cette thèse porte sur le rôle du cortex prémoteur dorsal (PMd) au sujet de la prise de décision (sélection d’une action parmis nombreux choix) et l'orientation visuelle des mouvements du bras. L’ouvrage décrit des expériences électrophysiologiques chez le singe éveillé (Macaca mulatta) permettant d’adresser une fraction importante des prédictions proposées par l'hypothèse des affordances concurrentes (Cisek, 2006; Cisek, 2007a). Cette hypothèse suggère que le choix de toute action est l’issue d'une concurrence entre les représentations internes des exigences et des atouts de chacune des options présentées (affordances; Gibson, 1979). Un intérêt particulier est donné au traitement de l'information spatiale et la valeur des options (expected value, EV) dans la prise de décisions. La première étude (article 1) explore la façon dont PMd reflète ces deux paramètres dans la période délai ainsi que de leur intéraction. La deuxième étude (article 2) explore le mécanisme de décision de façon plus détaillée et étend les résultats au cortex prémoteur ventral (PMv). Cette étude porte également sur la représentation spatiale et l’EV dans une perspective d'apprentissage. Dans un environnement nouveau les paramètres spatiaux des actions semblent être présents en tout temps dans PMd, malgré que la représentation de l’EV apparaît uniquement lorsque les animaux commencent à prendre des décisions éclairées au sujet de la valeur des options disponibles. La troisième étude (article 3) explore la façon dont PMd est impliqué aux “changements d'esprit“ dans un procès de décision. Cette étude décrit comment la sélection d’une action est mise à jour à la suite d'une instruction de mouvement (GO signal). I II Les résultats principaux des études sont reproduits par un modèle computationnel (Cisek, 2006) suggérant que la prise de décision entre plusieurs actions alternatives peux se faire par voie d’un mécanisme de concurrence (biased competition) qui aurait lieu dans la même région qui spécifie les actions., This thesis examines the role of the dorsal premotor cortex (PMd) in the process of decision making (action selection) and visual guidance of arm movements. The work describes electrophysiological experiments conducted in awake monkeys (Macaca mulatta) and tests a number of important predictions suggested by the affordance competition hypothesis (Cisek, 2006; Cisek, 2007a). This hypothesis suggests that decisions can be viewed as the result of a competition between internal representations of conflicting demands and opportunities for actions or affordances (Gibson, 1979). Specific interest is given to the interaction between spatial information and expected value (EV) in a proposed affordance competition mechanism for action selection. The first study presented (article 1) explores how EV is represented during the delay period in PMd. This study also describes how this area reflects the spatial metrics of the options and examines the interaction between value and spatial information. The second study (article 2) explores the mechanism of action selection in more detail and extends the results to ventral premotor cortex (PMv). This study also addresses the nature of value and spatial representations from a learning perspective. In a novel environment the spatial metrics of the actions seem to be invariably present in PMd, meanwhile EV representations appear only once the animals make behaviorally informed decisions about the value of the available options. The third study (article 3) explores how PMd is involved in “changes of mind” in which action selection is updated following a movement instruction (GO signal). III IV The major findings in all these studies are reproduced by a computational model (Cisek, 2006) suggesting that decisions between actions can be made through a biased competition process that takes place in the same region that specifies the actions.
- Published
- 2013
142. Biomechanical costs influence decisions made during ongoing actions.
- Author
-
Canaveral CA, Lata W, Green AM, and Cisek P
- Subjects
- Humans, Biomechanical Phenomena, Male, Female, Adult, Psychomotor Performance physiology, Young Adult, Movement physiology, Decision Making physiology
- Abstract
Accurate interaction with the environment relies on the integration of external information about the spatial layout of potential actions and knowledge of their costs and benefits. Previous studies have shown that when given a choice between voluntary reaching movements, humans tend to prefer actions with lower biomechanical costs. However, these studies primarily focused on decisions made before the onset of movement ("decide-then-act" scenarios), and it is not known to what extent their conclusions generalize to many real-life situations, in which decisions occur during ongoing actions ("decide-while-acting"). For example, one recent study found that biomechanical costs did not influence decisions to switch from a continuous manual tracking movement to a point-to-point movement, suggesting that biomechanical costs may be disregarded in decide-while-acting scenarios. To better understand this surprising result, we designed an experiment in which participants were faced with the decision between continuing to track a target moving along a straight path or changing paths to track a new target that gradually moved along a direction that deviated from the initial one. We manipulated tracking direction, angular deviation rate, and side of deviation, allowing us to compare scenarios where biomechanical costs favored either continuing or changing the path. Crucially, here the choice was always between two continuous tracking actions. Our results show that in this situation decisions clearly took biomechanical costs into account. Thus we conclude that biomechanics are not disregarded during decide-while-acting scenarios but rather that cost comparisons can only be made between similar types of actions. NEW & NOTEWORTHY In this study, we aim to shed light on how biomechanical factors influence decisions made during ongoing actions. Previous work suggested that decisions made during actions disregard biomechanical costs, in contrast to decisions made before movement. Our results challenge that proposal and suggest instead that the effect of biomechanical factors is dependent on the types of actions being compared (e.g., continuous tracking vs. point-to-point reaching). These findings contribute to our understanding of the dynamic interplay between biomechanical considerations and action choices during ongoing interactions with the environment.
- Published
- 2024
- Full Text
- View/download PDF
143. Toward a neuroscience of natural behavior.
- Author
-
Cisek P and Green AM
- Subjects
- Animals, Behavior, Animal physiology, Humans, Neurosciences methods
- Abstract
One of the most exciting new developments in systems neuroscience is the progress being made toward neurophysiological experiments that move beyond simplified laboratory settings and address the richness of natural behavior. This is enabled by technological advances such as wireless recording in freely moving animals, automated quantification of behavior, and new methods for analyzing large data sets. Beyond new empirical methods and data, however, there is also a need for new theories and concepts to interpret that data. Such theories need to address the particular challenges of natural behavior, which often differ significantly from the scenarios studied in traditional laboratory settings. Here, we discuss some strategies for developing such novel theories and concepts and some example hypotheses being proposed., Competing Interests: Declaration of competing interest The authors declare that no competing interests exist., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
144. Generating meaning: active inference and the scope and limits of passive AI.
- Author
-
Pezzulo G, Parr T, Cisek P, Clark A, and Friston K
- Subjects
- Humans, Learning, Artificial Intelligence, Brain
- Abstract
Prominent accounts of sentient behavior depict brains as generative models of organismic interaction with the world, evincing intriguing similarities with current advances in generative artificial intelligence (AI). However, because they contend with the control of purposive, life-sustaining sensorimotor interactions, the generative models of living organisms are inextricably anchored to the body and world. Unlike the passive models learned by generative AI systems, they must capture and control the sensory consequences of action. This allows embodied agents to intervene upon their worlds in ways that constantly put their best models to the test, thus providing a solid bedrock that is - we argue - essential to the development of genuine understanding. We review the resulting implications and consider future directions for generative AI., Competing Interests: Declaration of interests K.F. holds a chief scientific adviser position at VERSES AI. The other authors declare no conflicts of interest., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
145. Parallel processing of value-related information during multi-attribute decisions.
- Author
-
Nakahashi A and Cisek P
- Abstract
When choosing between options with multiple attributes, do we integrate all attributes into a unified measure for comparison, or does the comparison also occur at the level of each attribute, involving parallel processes that can dynamically influence each other? What happens when independent sensory features all carry information about the same decision factor, such as reward value? To investigate these questions, we asked human participants to perform a two-alternative forced choice reaching task in which the reward value of a target was indicated by two visual attributes-its brightness ("bottom-up," BU feature) and its orientation ("top-down," TD feature). If decisions always occur after the integration of both features, there should be no difference in the reaction time (RT) regardless of the attribute combinations that drove the choice. Counter to that prediction, RT distributions depended on the attribute combinations of given targets and the choices made by participants. RTs were shortest when both attributes were congruent or when the choice was based on the bottom-up feature, and longer when the attributes were in conflict (favoring opposite options). In conflict trials, nearly two-thirds of participants made faster decisions when choosing the option favored by the bottom-up feature than when choosing the top-down-favored option. We also observed mid-reach changes-of-mind in a subset of conflict trials, mostly changing from the bottom-up to the top-down-favored target. These data suggest that multi-attribute value-based decisions are better explained by a distributed process including competition among different features than by a competition based on a single, integrated estimate of value. NEW & NOTEWORTHY We show that during value-based decisions, humans do not always use all reward-related information to make their choice, but instead can "jump the gun" using partial information. In particular, when different sources of information were in conflict, early decisions were mostly based on fast bottom-up information, and sometimes followed by corrective changes-of-mind based on slower top-down information. This supports parallel decision processes among different information sources, as opposed to a single integrated "common currency."
- Published
- 2023
- Full Text
- View/download PDF
146. Beyond simple laboratory studies: Developing sophisticated models to study rich behavior.
- Author
-
Maselli A, Gordon J, Eluchans M, Lancia GL, Thiery T, Moretti R, Cisek P, and Pezzulo G
- Subjects
- Social Behavior, Ethology methods, Dissent and Disputes, Research Design, Neurosciences methods
- Abstract
Psychology and neuroscience are concerned with the study of behavior, of internal cognitive processes, and their neural foundations. However, most laboratory studies use constrained experimental settings that greatly limit the range of behaviors that can be expressed. While focusing on restricted settings ensures methodological control, it risks impoverishing the object of study: by restricting behavior, we might miss key aspects of cognitive and neural functions. In this article, we argue that psychology and neuroscience should increasingly adopt innovative experimental designs, measurement methods, analysis techniques and sophisticated computational models to probe rich, ecologically valid forms of behavior, including social behavior. We discuss the challenges of studying rich forms of behavior as well as the novel opportunities offered by state-of-the-art methodologies and new sensing technologies, and we highlight the importance of developing sophisticated formal models. We exemplify our arguments by reviewing some recent streams of research in psychology, neuroscience and other fields (e.g., sports analytics, ethology and robotics) that have addressed rich forms of behavior in a model-based manner. We hope that these "success cases" will encourage psychologists and neuroscientists to extend their toolbox of techniques with sophisticated behavioral models - and to use them to study rich forms of behavior as well as the cognitive and neural processes that they engage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
147. Performance-gated deliberation: A context-adapted strategy in which urgency is opportunity cost.
- Author
-
Puelma Touzel M, Cisek P, and Lajoie G
- Subjects
- Animals, Dopamine, Reinforcement, Psychology, Time Factors, Decision Making, Reward
- Abstract
Finding the right amount of deliberation, between insufficient and excessive, is a hard decision making problem that depends on the value we place on our time. Average-reward, putatively encoded by tonic dopamine, serves in existing reinforcement learning theory as the opportunity cost of time, including deliberation time. Importantly, this cost can itself vary with the environmental context and is not trivial to estimate. Here, we propose how the opportunity cost of deliberation can be estimated adaptively on multiple timescales to account for non-stationary contextual factors. We use it in a simple decision-making heuristic based on average-reward reinforcement learning (AR-RL) that we call Performance-Gated Deliberation (PGD). We propose PGD as a strategy used by animals wherein deliberation cost is implemented directly as urgency, a previously characterized neural signal effectively controlling the speed of the decision-making process. We show PGD outperforms AR-RL solutions in explaining behaviour and urgency of non-human primates in a context-varying random walk prediction task and is consistent with relative performance and urgency in a context-varying random dot motion task. We make readily testable predictions for both neural activity and behaviour., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
- Full Text
- View/download PDF
148. Resynthesizing behavior through phylogenetic refinement.
- Author
-
Cisek P
- Subjects
- Animals, Humans, Brain physiology, Cognition physiology, Phylogeny
- Abstract
This article proposes that biologically plausible theories of behavior can be constructed by following a method of "phylogenetic refinement," whereby they are progressively elaborated from simple to complex according to phylogenetic data on the sequence of changes that occurred over the course of evolution. It is argued that sufficient data exist to make this approach possible, and that the result can more effectively delineate the true biological categories of neurophysiological mechanisms than do approaches based on definitions of putative functions inherited from psychological traditions. As an example, the approach is used to sketch a theoretical framework of how basic feedback control of interaction with the world was elaborated during vertebrate evolution, to give rise to the functional architecture of the mammalian brain. The results provide a conceptual taxonomy of mechanisms that naturally map to neurophysiological and neuroanatomical data and that offer a context for defining putative functions that, it is argued, are better grounded in biology than are some of the traditional concepts of cognitive science.
- Published
- 2019
- Full Text
- View/download PDF
149. Navigating the Affordance Landscape: Feedback Control as a Process Model of Behavior and Cognition.
- Author
-
Pezzulo G and Cisek P
- Subjects
- Animals, Brain, Models, Biological, Behavior, Behavior, Animal, Cognition physiology
- Abstract
We discuss how cybernetic principles of feedback control, used to explain sensorimotor behavior, can be extended to provide a foundation for understanding cognition. In particular, we describe behavior as parallel processes of competition and selection among potential action opportunities ('affordances') expressed at multiple levels of abstraction. Adaptive selection among currently available affordances is biased not only by predictions of their immediate outcomes and payoffs but also by predictions of what new affordances they will make available. This allows animals to purposively create new affordances that they can later exploit to achieve high-level goals, resulting in intentional action that links across multiple levels of control. Finally, we discuss how such a 'hierarchical affordance competition' process can be mapped to brain structure., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
150. On the challenges and mechanisms of embodied decisions.
- Author
-
Cisek P and Pastor-Bernier A
- Subjects
- Animals, Humans, Behavior, Animal physiology, Brain physiology, Decision Making physiology, Environment
- Abstract
Neurophysiological studies of decision-making have focused primarily on elucidating the mechanisms of classic economic decisions, for which the relevant variables are the values of expected outcomes and action is simply the means of reporting the selected choice. By contrast, here we focus on the particular challenges of embodied decision-making faced by animals interacting with their environment in real time. In such scenarios, the choices themselves as well as their relative costs and benefits are defined by the momentary geometry of the immediate environment and change continuously during ongoing activity. To deal with the demands of embodied activity, animals require an architecture in which the sensorimotor specification of potential actions, their valuation, selection and even execution can all take place in parallel. Here, we review behavioural and neurophysiological data supporting a proposed brain architecture for dealing with such scenarios, which we argue set the evolutionary foundation for the organization of the mammalian brain., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.