scholarly journals Veto and Vacillation: A Neural Precursor of the Decision to Withhold Action

2014 ◽  
Vol 26 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Erman Misirlisoy ◽  
Patrick Haggard

The capacity to inhibit a planned action gives human behavior its characteristic flexibility. How this mechanism operates and what factors influence a decision to act or not act remain relatively unexplored. We used EEG readiness potentials (RPs) to examine preparatory activity before each action of an ongoing sequence, in which one action was occasionally omitted. We compared RPs between sequences in which omissions were instructed by a rule (e.g., “omit every fourth action”) and sequences in which the participant themselves freely decided which action to omit. RP amplitude was reduced for actions that immediately preceded a voluntary omission but not a rule-based omission. We also used the regular temporal pattern of the action sequences to explore brain processes linked to omitting an action by time-locking EEG averages to the inferred time when an action would have occurred had it not been omitted. When omissions were instructed by a rule, there was a negative-going trend in the EEG, recalling the rising ramp of an RP. No such component was found for voluntary omissions. The results are consistent with a model in which spontaneously fluctuating activity in motor areas of the brain could bias “free” decisions to act or not.

2005 ◽  
Vol 5 (1) ◽  
pp. 29-37
Author(s):  
elisabeth townsend

Humans: The Cooking Ape Perhaps the first to suggest that humans were cooking as early as 1.9 million years ago, Richard Wrangham shows through his new research and his imagination how and possibly when cooking changed humans dramatically. Wrangham, Harvard University primatologist and MacArthur Fellow, has been studying the evolution of human cooking. After 25 years of primate research at his site in Kibale, Uganda, Wrangham is best known for explaining the similarity and differences across species of primate social organizations. In Kibale, he has analyzed chimpanzees’ behavior: how it’s changed when they interact with the environment and how their social groups have evolved. In particular, he noticed how food changed their interactions with each other. Like that of chimps, human behavior has been affected by food, especially as they shifted from raw to cooked food. Moving from eating food as it was discovered to collecting edibles and cooking them altered our social relationships. Cooked food has changed Homo sapiens physically by making food more digestible thereby altering jaws, teeth, and guts, and providing more calories for more expensive organs such as the brain. Wrangham discusses when and how humans may have started using fire to cook food, what they cooked, and the transition from cooking in an outdoor fire to hearths and open ovens.


2021 ◽  
pp. 107385842110039
Author(s):  
Kristin F. Phillips ◽  
Harald Sontheimer

Once strictly the domain of medical and graduate education, neuroscience has made its way into the undergraduate curriculum with over 230 colleges and universities now offering a bachelor’s degree in neuroscience. The disciplinary focus on the brain teaches students to apply science to the understanding of human behavior, human interactions, sensation, emotions, and decision making. In this article, we encourage new and existing undergraduate neuroscience programs to envision neuroscience as a broad discipline with the potential to develop competencies suitable for a variety of careers that reach well beyond research and medicine. This article describes our philosophy and illustrates a broad-based undergraduate degree in neuroscience implemented at a major state university, Virginia Tech. We highlight the fact that the research-centered Experimental Neuroscience major is least popular of our four distinct majors, which underscores our philosophy that undergraduate neuroscience can cater to a different audience than traditionally thought.


Science ◽  
1936 ◽  
Vol 84 (2176) ◽  
pp. 10-10
Keyword(s):  

Stem Cells ◽  
2008 ◽  
Vol 26 (7) ◽  
pp. 1673-1682 ◽  
Author(s):  
Christine Rampon ◽  
Nicolas Weiss ◽  
Cyrille Deboux ◽  
Nathalie Chaverot ◽  
Florence Miller ◽  
...  

Author(s):  
G. Rapisarda ◽  
E. Bastings ◽  
A. Lozza ◽  
A. Maertens de Noordhout ◽  
P. J. Delwaide

2009 ◽  
Vol 101 (4) ◽  
pp. 1883-1889 ◽  
Author(s):  
Toshi Nakajima ◽  
Ryosuke Hosaka ◽  
Hajime Mushiake ◽  
Jun Tanji

We attempted to analyze the nature of premovement activity of neurons in medial motor areas [supplementary motor area (SMA) and pre-SMA] from a perspective of coding multiple movements. Monkeys were trained to perform a series of two movements with an intervening delay: supination or pronation with either forearm. Movements were initially instructed with visual signals but had to be remembered thereafter. Although a well-known type of premovement activity representing the forthcoming movements was found in the two areas, we found an unexpected type of activity that represented a second-next movement before initiating the first of the two movements. Typically in the pre-SMA, such activity selective for the second-next movement peaked before the initiation of the first movement, decayed thereafter, and remained low in magnitude while initiating the second movement. This type of activity may tentatively hold information for the second movement while initiating the first. That information may be fed into another group of neurons that themselves build a preparatory activity required to plan the second movements. Alternatively, the activity could serve as a signal to inhibit a premature exertion of the motor command for the second movement.


Brain ◽  
1888 ◽  
Vol 11 (2) ◽  
pp. 225-227
Author(s):  
J. MUNRO SMITH
Keyword(s):  

1990 ◽  
Vol 13 (3) ◽  
pp. 471-489 ◽  
Author(s):  
Stephen José Hanson ◽  
David J. Burr

AbstractConnectionist models provide a promising alternative to the traditional computational approach that has for several decades dominated cognitive science and artificial intelligence, although the nature of connectionist models and their relation to symbol processing remains controversial. Connectionist models can be characterized by three general computational features: distinct layers of interconnected units, recursive rules for updating the strengths of the connections during learning, and “simple” homogeneous computing elements. Using just these three features one can construct surprisingly elegant and powerful models of memory, perception, motor control, categorization, and reasoning. What makes the connectionist approach unique is not its variety of representational possibilities (including “distributed representations”) or its departure from explicit rule-based models, or even its preoccupation with the brain metaphor. Rather, it is that connectionist models can be used to explore systematically the complex interaction between learning and representation, as we try to demonstrate through the analysis of several large networks.


1993 ◽  
Vol 79 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Christian Strauss ◽  
Johann Romstöck ◽  
Christopher Nimsky ◽  
Rudolf Fahlbusch

✓ Intraoperative electrical identification of motor areas within the floor of the fourth ventricle was successfully carried out in a series of 10 patients with intrinsic pontine lesions and lesions infiltrating the brain stem. Direct electrical stimulation was used to identify the facial colliculus and the hypoglossal triangle before the brain stem was entered. Multichannel electromyographic recordings documented selective stimulation effects. The surgical approach to the brain stem was varied according to the electrical localization of these structures. During removal of the lesion, functional integrity was monitored by intermittent stimulation. In lesions infiltrating the floor of the fourth ventricle, stimulation facilitated complete removal. Permanent postoperative morbidity of facial or hypoglossal nerve dysfunction was not observed. Mapping of the floor of the fourth ventricle identifies important surface structures and offers a safe corridor through intact nervous structures during surgery of brain-stem lesions. Reliable identification is particularly important in mass lesions with displacement of normal topographical anatomy.


2021 ◽  
Author(s):  
Kosuke Hamaguchi ◽  
Hiromi Takahashi-Aoki ◽  
Dai Watanabe

Animals must flexibly estimate the value of their actions to successfully adapt in a changing environment. The brain is thought to estimate action-value from two different sources, namely the action-outcome history (retrospective value) and the knowledge of the environment (prospective value). How these two different estimates of action-value are reconciled to make a choice is not well understood. Here we show that as a mouse learns the state-transition structure of a decision-making task, retrospective and prospective values become jointly encoded in the preparatory activity of neurons in the frontal cortex. Suppressing this preparatory activity in expert mice returned their behavior to a naive state. These results reveal the neural circuit that integrates knowledge about the past and future to support predictive decision-making.


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