Space Coding in Inferior Premotor Cortex (Area F4): Facts and Speculations

1996 ◽  
pp. 99-120 ◽  
Author(s):  
L. Fogassi ◽  
V. Gallese ◽  
L. Fadiga ◽  
G. Rizzolatti
Keyword(s):  
Premotor Cortex ◽  
Cortex Area ◽  
Space Coding

scholarly journals Corticospinal mirror neurons

2014 ◽  
Vol 369 (1644) ◽  
pp. 20130174 ◽  
Author(s):  
A. Kraskov ◽  
R. Philipp ◽  
S. Waldert ◽  
G. Vigneswaran ◽  
M. M. Quallo ◽  
...  
Keyword(s):  
Mirror Neurons ◽  
Primary Motor Cortex ◽  
Mirror Neuron System ◽  
Action Observation ◽  
Premotor Cortex ◽  
Mirror Neuron ◽  
Considerable Proportion ◽  
Emg Activity ◽  
Cortex Area ◽  
Similar Range

Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

scholarly journals Philosophy and neuroscience: relation between mirror neurons and empathy

2018 ◽  
Author(s):  
Santiago Arteaga
Keyword(s):  
Human Brain ◽  
Mirror Neurons ◽  
Premotor Cortex ◽  
Edith Stein ◽  
Ventral Premotor Cortex ◽  
Cortex Area

Ever since the discovery of mirror neurons in the ventral premotor cortex (area F5) of the macaque brain, in the late 1980s, by Rizzolatti and his University of Parma colleagues, the question was put forward whether the same type of neurons could be found in the human brain. Could it be possible that these same neurons that activate not only when the monkey reaches for or takes a bite out of some sort of food -like a nut or a raisin- but also when someone picks it up to hand it to the monkey, be found in our brains? This essay does not have the scope to consider all concepts of empathy nor to include all relevant studies on mirror neurons concerning its relation to empathy. That being so, I shall take the following path: 1) introduce mirror neurons, what they are, where they are and their implications; 2) consider some aspects of empathy from different areas of research and present Edith Stein and Theodor Lipps's ideas; 3) relate the philosophers' ideas with the discussion put forward by Iacoboni, Gallese, Rizzolatti and Ramachandran concerning mirror neurons and empathy.

scholarly journals Neural Systems Underlying Decisions about Affective Odors

2010 ◽  
Vol 22 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Edmund T. Rolls ◽  
Fabian Grabenhorst ◽  
Benjamin A. Parris
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Premotor Cortex ◽  
Anterior Cingulate ◽  
Fmri Study ◽  
Cortex Area ◽  
Dorsolateral Prefrontal ◽  
Affective Value ◽  
Medial Pfc ◽  
Medial Area

Decision-making about affective value may occur after the reward value of a stimulus is represented and may involve different brain areas to those involved in decision-making about the physical properties of stimuli, such as intensity. In an fMRI study, we delivered two odors separated by a delay, with instructions on different trials to decide which odor was more pleasant or more intense or to rate the pleasantness and intensity of the second odor without making a decision. The fMRI signals in the medial prefrontal cortex area 10 (medial PFC) and in regions to which it projects, including the anterior cingulate cortex (ACC) and insula, were higher when decisions were being made compared with ratings, implicating these regions in decision-making. Decision-making about affective value was related to larger signals in the dorsal part of medial area 10 and the agranular insula, whereas decisions about intensity were related to larger activations in the dorsolateral prefrontal cortex (dorsolateral PFC), ventral premotor cortex, and anterior insula. For comparison, the mid orbitofrontal cortex (OFC) had activations related not to decision-making but to subjective pleasantness ratings, providing a continuous representation of affective value. In contrast, areas such as medial area 10 and the ACC are implicated in reaching a decision in which a binary outcome is produced.

Specific binding of [3H]phenytoin in the human brain

1985 ◽  
Vol 63 (5) ◽  
pp. 517-518 ◽  
Author(s):  
L. Spero
Keyword(s):  
Motor Cortex ◽  
Human Brain ◽  
Binding Sites ◽  
Parietal Lobe ◽  
Specific Binding ◽  
Premotor Cortex ◽  
Lower Affinity ◽  
Inferior Parietal Lobe ◽  
Cortex Area ◽  
Normal Human

Competition between cold phenytoin and [3H]phenytoin binding was observed in normal human brain. Binding was observed in all areas examined. The highest number of sites was in the amygdala (a total of 717.71 fmol/mg protein) and the lowest in the Brodman area (BA) 4 of the motor cortex (153.91 fmol/mg protein) and cerebellar cortex (154.4 fmol/mg protein). In three areas, amygdala, cortex area BA 38 (inferior parietal lobe), and cortex area BA 8 (premotor cortex), two sets of binding sites were observed. In these areas the Kd for the higher affinity sites ranged from 35 to 116 nM, and for the lower affinity site, from 328 to 866 nM. In the four areas where only one binding site was observed the Kds ranged from 164 to 311 nM and the Scatchard plot was linear.

Facilitation From Ventral Premotor Cortex of Primary Motor Cortex Outputs to Macaque Hand Muscles

2003 ◽  
Vol 90 (2) ◽  
pp. 832-842 ◽  
Author(s):  
G. Cerri ◽  
H. Shimazu ◽  
M. A. Maier ◽  
R. N. Lemon
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Macaque Monkey ◽  
Hand Muscles ◽  
Ventral Premotor Cortex ◽  
Cortex Area ◽  
Light Sedation ◽  
Cortical Inputs ◽  
Motor Representations

We demonstrate that in the macaque monkey there is robust, short-latency facilitation by ventral premotor cortex (area F5) of motor outputs from primary motor cortex (M1) to contralateral intrinsic hand muscles. Experiments were carried out on two adult macaques under light sedation (ketamine plus medetomidine HCl). Facilitation of hand muscle electromyograms (EMG) was tested using arrays of fine intracortical microwires implanted, respectively, in the wrist/digit motor representations of F5 and M1, which were identified by previous mapping with intracortical microstimulation. Single pulses (70–200 μA) delivered to F5 microwires never evoked any EMG responses, but small responses were occasionally seen with double pulses (interval: 3 ms) at high intensity. However, both single- and double-pulse stimulation of F5 could facilitate the EMG responses evoked from M1 by single shocks. The facilitation was large (up to 4-fold with single and 12-fold with double F5 shocks) and occurred with an early onset, with significant effects at intervals of only 1–2 ms between conditioning F5 and test M1 stimuli. A number of possible pathways could be responsible for these effects, although it is argued that the most likely mechanism would be the facilitation, by cortico-cortical inputs from F5, of corticospinal I wave activity evoked from M1. This facilitatory action could be of considerable importance for the coupling of grasp-related neurons in F5 and M1 during visuomotor tasks.

scholarly journals Responses of single corticospinal neurons to intracortical stimulation of primary motor and premotor cortex in the anesthetized macaque monkey

2013 ◽  
Vol 109 (12) ◽  
pp. 2982-2998 ◽  
Author(s):  
Marc A. Maier ◽  
Peter A. Kirkwood ◽  
Thomas Brochier ◽  
Roger N. Lemon
Keyword(s):  
Cervical Spinal Cord ◽  
Premotor Cortex ◽  
Single Pulse ◽  
Macaque Monkey ◽  
Periodic Surface ◽  
Hand Muscles ◽  
Cortex Area ◽  
In Trans ◽  
Hand Area ◽  
Stimulation Of

The responses of individual primate corticospinal neurons to localized electrical stimulation of primary motor (M1) and of ventral premotor cortex (area F5) are poorly documented. To rectify this and to study interactions between responses from these areas, we recorded corticospinal axons, identified by pyramidal tract stimulation, in the cervical spinal cord of three chloralose-anesthetized macaque monkeys. Single stimuli (≤400 μA) were delivered to the hand area of M1 or F5 through intracortical microwire arrays. Only 14/112 (13%) axons showed responses to M1 stimuli that indicated direct intracortical activation of corticospinal neurons (D-responses); no D-responses were seen from F5. In contrast, 62 axons (55%) exhibited consistent later responses to M1 stimulation, corresponding to indirect activation (I-responses), showing that single-pulse intracortical stimulation of motor areas can result in trans-synaptic activation of a high proportion of the corticospinal output. A combined latency histogram of all axon responses was nonperiodic, clearly different from the periodic surface-recorded corticospinal volleys. This was readily explained by correcting for conduction velocities of individual axons. D-responding axons, taken as originating in neurons close to the M1 stimulating electrodes, showed more I-responses from M1 than those without a D-response, and 8/10 of these axons also responded to F5 stimulation. Altogether, 33% of tested axons responded to F5 stimulation, most of which also showed I-responses from M1. These excitatory effects are in keeping with facilitation of hand muscles evoked from F5 being relayed via M1. This was further demonstrated by facilitation of test responses from M1 by conditioning F5 stimuli.

Imagery of Voluntary Movement of Fingers, Toes, and Tongue Activates Corresponding Body-Part-Specific Motor Representations

2003 ◽  
Vol 90 (5) ◽  
pp. 3304-3316 ◽  
Author(s):  
H. Henrik Ehrsson ◽  
Stefan Geyer ◽  
Eiichi Naito
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Body Part ◽  
Cortical Activation ◽  
Motor Area ◽  
Cortex Area ◽  
Area 6 ◽  
Motor Areas

We investigate whether imagery of voluntary movements of different body parts activates somatotopical sections of the human motor cortices. We used functional magnetic resonance imaging to detect the cortical activity when 7 healthy subjects imagine performing repetitive (0.5-Hz) flexion/extension movements of the right fingers or right toes, or horizontal movements of the tongue. We also collected functional images when the subjects actually executed these movements and used these data to define somatotopical representations in the motor areas. In this study, we relate the functional activation maps to cytoarchitectural population maps of areas 4a, 4p, and 6 in the same standard anatomical space. The important novel findings are 1) that imagery of hand movements specifically activates the hand sections of the contralateral primary motor cortex (area 4a) and the contralateral dorsal premotor cortex (area 6) and a hand representation located in the caudal cingulate motor area and the most ventral part of the supplementary motor area; 2) that when imagining making foot movements, the foot zones of the posterior part of the contralateral supplementary motor area (area 6) and the contralateral primary motor cortex (area 4a) are active; and 3) that imagery of tongue movements activates the tongue region of the primary motor cortex and the premotor cortex bilaterally (areas 4a, 4p, and 6). These results demonstrate that imagery of action engages the somatotopically organized sections of the primary motor cortex in a systematic manner as well as activating some body-part-specific representations in the nonprimary motor areas. Thus the content of the mental motor image, in this case the body part, is reflected in the pattern of motor cortical activation.

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