The Urge to Decide and Act: Implications for Brain Function and Dysfunction

2019 ◽  
Vol 25 (5) ◽  
pp. 491-511 ◽  
Author(s):  
Matthew A. Carland ◽  
David Thura ◽  
Paul Cisek
Keyword(s):  
Action Execution ◽  
Behavioral Measures ◽  
Reward Rate ◽  
Rate Maximization ◽  
Individual Trait ◽  
Wide Range ◽  
Neurophysiological Data ◽  
Reward Rate Maximization ◽  
Potential Link ◽  
Cortical Regions

Humans and other animals are motivated to act so as to maximize their subjective reward rate. Here, we propose that reward rate maximization is accomplished by adjusting a context-dependent “urgency signal,” which influences both the commitment to a developing action choice and the vigor with which the ensuing action is performed. We review behavioral and neurophysiological data suggesting that urgency is controlled by projections from the basal ganglia to cerebral cortical regions, influencing neural activity related to decision making as well as activity related to action execution. We also review evidence suggesting that different individuals possess specific policies for adjusting their urgency signal to particular contextual variables, such that urgency constitutes an individual trait which jointly influences a wide range of behavioral measures commonly related to the overall quality and hastiness of one’s decisions and actions. Consequently, we argue that a central mechanism for reward rate maximization provides a potential link between personality traits such as impulsivity, as well as some of the motivation-related symptomology of clinical disorders such as depression and Parkinson’s disease.

Discarding optimality: Throwing out the baby with the bathwater?

2018 ◽  
Vol 41 ◽  
Author(s):  
Patrick Simen ◽  
Fuat Balcı
Keyword(s):  
Decision Making ◽  
Perceptual Decision Making ◽  
Reward Rate ◽  
Perceptual Decision ◽  
Standard Observer ◽  
Rate Maximization ◽  
Reward Rate Maximization ◽  
Descriptive Standard ◽  
Observer Model

AbstractRahnev & Denison (R&D) argue against normative theories and in favor of a more descriptive “standard observer model” of perceptual decision making. We agree with the authors in many respects, but we argue that optimality (specifically, reward-rate maximization) has proved demonstrably useful as a hypothesis, contrary to the authors’ claims.

scholarly journals Anatomical and functional organization of the human substantia nigra and its connections

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Yu Zhang ◽  
Kevin Michel-Herve Larcher ◽  
Bratislav Misic ◽  
Alain Dagher
Keyword(s):  
Substantia Nigra ◽  
Functional Organization ◽  
Impulsive Choice ◽  
Behavioral Measures ◽  
Human Connectome Project ◽  
Motor Impulsivity ◽  
Cortical Regions ◽  
Value Coding ◽  
Decisional Impulsivity ◽  
Human Substantia Nigra

We investigated the anatomical and functional organization of the human substantia nigra (SN) using diffusion and functional MRI data from the Human Connectome Project. We identified a tripartite connectivity-based parcellation of SN with a limbic, cognitive, motor arrangement. The medial SN connects with limbic striatal and cortical regions and encodes value (greater response to monetary wins than losses during fMRI), while the ventral SN connects with associative regions of cortex and striatum and encodes salience (equal response to wins and losses). The lateral SN connects with somatomotor regions of striatum and cortex and also encodes salience. Behavioral measures from delay discounting and flanker tasks supported a role for the value-coding medial SN network in decisional impulsivity, while the salience-coding ventral SN network was associated with motor impulsivity. In sum, there is anatomical and functional heterogeneity of human SN, which underpins value versus salience coding, and impulsive choice versus impulsive action.

scholarly journals Hippocampal Contributions to Episodic Encoding: Insights From Relational and Item-Based Learning

2002 ◽  
Vol 88 (2) ◽  
pp. 982-990 ◽  
Author(s):  
Lila Davachi ◽  
Anthony D. Wagner
Keyword(s):  
Working Memory ◽  
Medial Temporal Lobe ◽  
Memory Formation ◽  
Relational Processing ◽  
Behavioral Measures ◽  
Fmri Study ◽  
Episodic Encoding ◽  
Hippocampus Proper ◽  
Temporal Structures ◽  
Cortical Regions

The integrity of the hippocampus and surrounding medial-temporal cortices is critical for episodic memory, with the hippocampus being posited to support relational or configural associative learning. The present event-related functional magnetic resonance imaging (fMRI) study investigated the role of specific medial-temporal lobe structures in learning during relational and item-based processing, as well as the extent to which these structures are engaged during item-based maintenance of stimuli in working memory. fMRI indexed involvement of the hippocampus and underlying cortical regions during performance of two verbal encoding conditions, one that required item-based maintenance of word triplets in working memory and the other that entailed the formation of inter-item associations across the words in each triplet. Sixteen subjects were scanned using a rapid event-related fMRI design while they encountered the item-based and relational processing trials. To examine the correlation between fMRI signal in medial-temporal structures during learning and the subject's subsequent ability to remember the stimuli (a measure of effective memory formation), subjects were administered a yes-no recognition memory test following completion of the encoding scans. Results revealed that the hippocampus proper was engaged during both relational and item-based processing, with relational processing resulting in a greater hippocampal response. By contrast, entorhinal and parahippocampal gyri were differentially engaged during item-based processing, providing strong evidence for a functional neuroanatomic distinction between hippocampal and parahippocampal structures. Analysis of the neural correlates of subsequent memory revealed that activation in the bilateral hippocampus was reliably correlated with behavioral measures of effective memory formation only for those stimuli that were encoded in a relational manner. Taken together, these data provide evidence that the hippocampus, while engaged during item-based working memory maintenance, differentially subserves the relational binding of items into an integrated memory trace so that the experience can be later remembered.

scholarly journals Synaptic Signals from Glutamate-Treated Neurons Induce Aberrant Post-Synaptic Signals in Untreated Neuronal Networks

2020 ◽  
Vol 14 (1) ◽  
pp. 59-62
Author(s):  
Mary Guaraldi ◽  
Sangmook Lee ◽  
Thomas B. Shea
Keyword(s):  
Cortical Neurons ◽  
Neuronal Networks ◽  
Synaptic Function ◽  
Glutamate Excitotoxicity ◽  
Synaptic Connectivity ◽  
Extracellular Glutamate ◽  
Glutamate Neurotoxicity ◽  
Wide Range ◽  
Cortical Regions

Background and Objective: Glutamate neurotoxicity is associated with a wide range of disorders and can impair synaptic function. Failure to clear extracellular glutamate fosters additional cycles and spread of regional hyperexcitation. Methods and Results: Using cultured murine cortical neurons, herein it is demonstrated that synaptic signals generated by cultures undergoing glutamate-induced hyperactivity can invoke similar effects in other cultures not exposed to elevated glutamate. Conclusion: Since sequential synaptic connectivity can encompass extensive cortical regions, this study presents a potential additional contributor to the spread of damage resulting from glutamate excitotoxicity and should be considered in attempts to mitigate neurodegeneration.

scholarly journals The Human Intraparietal Sulcus Modulates Task-Evoked Functional Connectivity

2019 ◽  
Vol 30 (3) ◽  
pp. 875-887
Author(s):  
Kai Hwang ◽  
James M Shine ◽  
Dillan Cellier ◽  
Mark D’Esposito
Keyword(s):  
Functional Connectivity ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Intraparietal Sulcus ◽  
Top Down ◽  
Adaptive Communication ◽  
Wide Range ◽  
Functional Connectivity Strength ◽  
Ventral Temporal Cortex ◽  
Cortical Regions

Abstract Past studies have demonstrated that flexible interactions between brain regions support a wide range of goal-directed behaviors. However, the neural mechanisms that underlie adaptive communication between brain regions are not well understood. In this study, we combined theta-burst transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging to investigate the sources of top-down biasing signals that influence task-evoked functional connectivity. Subjects viewed sequences of images of faces and buildings and were required to detect repetitions (2-back vs. 1-back) of the attended stimuli category (faces or buildings). We found that functional connectivity between ventral temporal cortex and the primary visual cortex (VC) increased during processing of task-relevant stimuli, especially during higher memory loads. Furthermore, the strength of functional connectivity was greater for correct trials. Increases in task-evoked functional connectivity strength were correlated with increases in activity in multiple frontal, parietal, and subcortical (caudate and thalamus) regions. Finally, we found that TMS to superior intraparietal sulcus (IPS), but not to primary somatosensory cortex, decreased task-specific modulation in connectivity patterns between the primary VC and the parahippocampal place area. These findings demonstrate that the human IPS is a source of top-down biasing signals that modulate task-evoked functional connectivity among task-relevant cortical regions.

scholarly journals Is the Exposome Involved in Brain Disorders through the Serotoninergic System?

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1351
Author(s):  
Denis Sarrouilhe ◽  
Norah Defamie ◽  
Marc Mesnil
Keyword(s):  
Serotoninergic System ◽  
Vasoactive Agent ◽  
Neurodevelopmental Toxicity ◽  
Wide Range ◽  
Potential Link ◽  
Common Etiology ◽  
The Central Nervous System ◽  
Health And Disease ◽  
Biogenic Monoamine

Serotonin (5-hydroxytryptamine, 5-HT) is a biogenic monoamine acting as a neurotransmitter in the central nervous system (CNS), local mediator in the gut, and vasoactive agent in the blood. It has been linked to a variety of CNS functions and is implicated in many CNS and psychiatric disorders. The high comorbidity between some neuropathies can be partially understood by the fact that these diseases share a common etiology involving the serotoninergic system. In addition to its well-known functions, serotonin has been shown to be a mitogenic factor for a wide range of normal and tumor cells, including glioma cells, in vitro. The developing CNS of fetus and newborn is particularly susceptible to the deleterious effects of neurotoxic substances in our environment, and perinatal exposure could result in the later development of diseases, a hypothesis known as the developmental origin of health and disease. Some of these substances affect the serotoninergic system and could therefore be the source of a silent pandemic of neurodevelopmental toxicity. This review presents the available data that are contributing to the appreciation of the effects of the exposome on the serotoninergic system and their potential link with brain pathologies (neurodevelopmental, neurodegenerative, neurobehavioral disorders, and glioblastoma).

scholarly journals All-or-none visual categorization in the human brain

2019 ◽  
Author(s):  
Talia L. Retter ◽  
Fang Jiang ◽  
Michael A. Webster ◽  
Bruno Rossion
Keyword(s):  
Human Brain ◽  
Visual Presentation ◽  
Neural Responses ◽  
Behavioral Measures ◽  
Visual Categorization ◽  
Visual Events ◽  
Face Categorization ◽  
Wide Range ◽  
The Face ◽  
Spatio Temporal

AbstractWhether visual categorization, i.e., specific responses to a certain class of visual events across a wide range of exemplars, is graded or all-or-none in the human brain is largely unknown. We address this issue with an original frequency-sweep paradigm probing the evolution of responses between the minimum and optimal presentation times required to elicit both neural and behavioral face categorization responses. In a first experiment, widely variable natural images of nonface objects are progressively swept from 120 to 3 Hz (8.33 to 333 ms duration) in rapid serial visual presentation sequences; variable face exemplars appear every 1 s, enabling an implicit frequency-tagged face-categorization electroencephalographic (EEG) response at 1 Hz. In a second experiment, faces appear non-periodically throughout such sequences at fixed presentation rates, while participants explicitly categorize faces. Face-categorization activity emerges with stimulus durations as brief as 17 ms for both neural and behavioral measures (17 – 83 ms across individual participants neurally; 33 ms at the group level). The face-categorization response amplitude increases until 83 ms stimulus duration (12 Hz), implying graded categorization responses. However, a strong correlation with behavioral accuracy suggests instead that dilution from missed categorizations, rather than a decreased response to each face stimulus, may be responsible. This is supported in the second experiment by the absence of neural responses to behaviorally uncategorized faces, and equivalent amplitudes of isolated neural responses to only behaviorally categorized faces across presentation rates, consistent with the otherwise stable spatio-temporal signatures of face-categorization responses in both experiments. Overall, these observations provide original evidence that visual categorization of faces, while being widely variable across human observers, occurs in an all-or-none fashion in the human brain.

scholarly journals Predicting Reading From Behavioral and Neural Measures – A Longitudinal Event-Related Potential Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Aleksandra K. Eberhard-Moscicka ◽  
Lea B. Jost ◽  
Moritz M. Daum ◽  
Urs Maurer
Keyword(s):  
Early Stage ◽  
Block Design ◽  
Reading Acquisition ◽  
Event Related Potentials ◽  
First Grade ◽  
Event Related Potential ◽  
Audiovisual Integration ◽  
Behavioral Measures ◽  
Wide Range ◽  
Related Potentials

Fluent reading is characterized by fast and effortless decoding of visual and phonological information. Here we used event-related potentials (ERPs) and neuropsychological testing to probe the neurocognitive basis of reading in a sample of children with a wide range of reading skills. We report data of 51 children who were measured at two time points, i.e., at the end of first grade (mean age 7.6 years) and at the end of fourth grade (mean age 10.5 years). The aim of this study was to clarify whether next to behavioral measures also basic unimodal and bimodal neural measures help explaining the variance in the later reading outcome. Specifically, we addressed the question of whether next to the so far investigated unimodal measures of N1 print tuning and mismatch negativity (MMN), a bimodal measure of audiovisual integration (AV) contributes and possibly enhances prediction of the later reading outcome. We found that the largest variance in reading was explained by the behavioral measures of rapid automatized naming (RAN), block design and vocabulary (46%). Furthermore, we demonstrated that both unimodal measures of N1 print tuning (16%) and filtered MMN (7%) predicted reading, suggesting that N1 print tuning at the early stage of reading acquisition is a particularly good predictor of the later reading outcome. Beyond the behavioral measures, the two unimodal neural measures explained 7.2% additional variance in reading, indicating that basic neural measures can improve prediction of the later reading outcome over behavioral measures alone. In this study, the AV congruency effect did not significantly predict reading. It is therefore possible that audiovisual congruency effects reflect higher levels of multisensory integration that may be less important for reading acquisition in the first year of learning to read, and that they may potentially gain on relevance later on.

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