Mirror Neurons in the Macaque Monkey: A Critical Review.

In a number of experimental studies carried out in Italy in the early 1990s, it was observed that a set of neurons from the macaque monkey premotor cortex is activated both when a specific action is performed and when the same action is simply observed. These neurons were given the evocative name of "mirror neurons". In this article, the conclusions from these studies and subsequent elaborations are reviewed in order to examine their soundness in theoretical terms.

Evaluation of remote monitoring of parturition in dairy cattle as a new tool for calving management.

BACKGROUND: Proper calving management of dairy herds is a crucial aspect of the bovine life cycle, as it has profound effects on calf viability and on the post-partum course of the dam. The objectives of this study were to monitor the calving process through the use of a remote alarm system and to determine the impact of prompt emergency obstetric procedures in case of dystocia for the prevention of stillbirths and post-partum reproductive pathologies, and for improving herd fertility. Six groups of experimental animals were studied: monitored heifers (n = 60) and multiparous cows (n = 60) were compared with non-observed animals (n = 60 heifers and n = 60 multiparous) giving birth during the same time period and housed in the calving barn, and with unmonitored animals placed in a dry zone (n = 240 heifers and n = 112 multiparous cows). RESULTS: The incidence of dystocia ranged from a minimum of 23.4% (monitored multiparous cows) to a maximum of 33.3% (monitored heifers), and there were no differences compared with control groups. However, the rate of stillbirth was higher in control groups than in the monitored groups (P < 0.01). Among both heifers and multiparous cows, the incidence of post-partum uterine infections was higher in the unmonitored animals both in the calving barn (P < 0.01) and in the dry zone (P < 0.05) compared with monitored animals. Among both heifers and multiparous cows, the control groups showed higher rates of foetal membrane retention than did the monitored groups (P < 0.001). The calving-to-conception interval was shorter; in particular, observed heifers showed a significant advantage of approximately 46 days compared with the unmonitored group (P < 0.001) and 32 days compared with the group in the calving barn (P < 0.05). Multiparous cows also had a reduction in the number of days open. CONCLUSIONS: The remote alarm system used to monitor the calving process assured the prompt presence of personnel, improving both the cow's reproductive efficiency and neonatal viability.

The mirror neuron system simply. An hypothesis? - biomed 2013.

The announcement that mirror neurons (MNs) had been found in macaques was made in 1996. The ensuing MN System theory (MNST) was based on the “nearly simultaneous” activity of some neurons detected both when the macaque observed an investigator's action and when it performed the action (e.g. grasp to eat). Studying the seminal investigations on macaques published in the literature, we realized that poorly defined time-scales could lead to multiple interpretations. We also noticed that in the original experimental protocol the synchronization between the observed event and the neural activity hypothetically related to the event itself was not investigated. In spite of this criticism, the MNST has enjoyed an extraordinary popularity in general media as well as in the scientific community, and monkeys have, almost magically, acquired the functional ability of MNs. In this paper, we analyze some recent studies about the MNST, specifically those about direct measurements on humans by means of implanted electrodes performed by Mukamel and colleagues in 2010. We also consider some experiments performed on monkeys by Rochat et al. in 2010 and some indirect measurements on humans made by Kujala et al. in 2012. We find the conclusions of the authors of these works to be quite simplistic relative to the inherent complexity of neural networks, reinforcing our interpretation against the MNST. We suggest the reported measurements are the result of conventional neural activity related to the events considered (i.e. grasping, both observed and executed) and are not necessarily imputable to the hypothetical MNs.

A novel methodology to evaluate the psycho-physical condition of individuals performing at-risk activities.

Currently the evaluation of the psycho-physical condition of individuals performing at-risk activities involves either subjective evaluations or invasive biological tests, and is not often indicative of the actual ability of the subject to perform the specific activity. We propose a new methodology based on posturographic and reaction time measurements, derived from the strict relationship between the control strategies used to maintain the erect posture and the psycho-physical abilities of an individual. These strategies are affected by fatigue, diseases and substances such as alcohol and drugs. The measuring device consists of a posturographic platform, a hand-held trigger and a personal computer running the software. The subject is asked to perform simultaneously two tasks: move the center of mass of the body to follow a target on the screen, and react to the appearance of another stimulus by pressing the trigger. The task is made more complicated by randomly presenting the stimuli and by the presence of “dummy” targets the subject is supposed to ignore. Evaluating how accurately the subject follows the target, the reaction times, as well as the number of reactions to “dummy” targets allows to quantify the psycho-physical condition of the individual. This methodology could be used as a real time, fast and quantitative measure to improve road and workplace safety, not invading the privacy of the subject, easily relating to real-world activities, and not requiring highly trained personnel to administer the test.

Learning effect of standing on foam during posturographic testing – preliminary findings.

Balance protocols such as the modified Clinical Test of Sensory Integration on Balance (mCTSIB) or the Balance Error Scoring System (BESS) include testing a person while standing on a thick foam cushion. The role of the foam cushion is to perturb the somatosensory and proprioceptive information and to provide an unstable and unpredictable standing surface. This, combined with asking the subject to keep the eyes closed during the test, is to make the subject rely mostly on the vestibular system to maintain balance. However, this type of condition rarely occurs in real life. It is not well understood if learning and/or fatiguing might affect the results of these type of tests. This has important methodological consequences for balance protocols in terms of the number of repetitions and how these might affect the results of the balance tests. In this study, the balance of 25 healthy subjects who had never undergone this type of testing was evaluated. The subjects performed in rapid succession 4, 60s long posturographic tests while standing on a foam cushion. A computerized posturographic device was used to collect the data. Half of the participants performed the tests with eyes open and half with eyes closed. This allowed to discover the presence of a “learning effect” the first time subjects are tested on the foam cushion. Once the subjects had learned to stand on the foam cushion, the length of the tests and the number of repetitions did not show a statistically significant effect.

A biomechanical modelof the arthrosis of the hip joint - biomed 2011.

The hip joint has been investigated in depth, but causes of algic (pain) phenomena, especially those apparently located at the knee (referred pain), still remain unclear. Using a bi-dimensional multi-body model we investigated the effect of arthrosis on the kinematic of the hip joint and its relationship to pain. The bone was modeled as a rigid structure whereas the capsule and cartilage were assumed to be deformable. The effects of arthrosis were simulated as reduction of the thickness of the deformable tissues and increased friction. The extension velocity of the rectus femori and the trajectory of the instantaneous center of rotation (ICR) were examined for both physiological conditions and advanced degrees of arthrosis.In physiological conditions, results show that the extension velocity of the muscle has slight irregularities but is nevertheless continuous. The presence of arthrosis leads to a localized increase in friction and the model shows a migration of the location of the ICR toward the acetabulum. Changes in the ICR due to irregular surface friction, cartilage erosion as well as lack of synovial fluid, which in normal conditions ensures boundary film lubrication, induce discontinuities in the extension velocity of the muscle which are detected by the proprioceptive system (e.g. Golgi tendon organ) generating algic phenomena.The results of the model confirmed these findings and how hip arthrosis, in producing changes in the extension velocity of the muscle and in the kinematic of the movement, results in muscle and tendon pain around the knee.

Autism and motor acts: experimental analysison mylohyoid muscle emg recordingsduring grasping-to-eat action - biomed 2010.

Most neuroscience studies do not pay enough attention to bio-mechanical related problems, such as the kinematic aspects of movements, that pose important boundary conditions, but are in general not sufficiently taken into consideration. In this work, using an experimental protocol based on measurements of mylohyoid (MH) muscle activity during grasping-to-eat actions, we debate the existence of impairments of action chains in children with autism spectrum disorders (ASD). We re-examine the results of an electromyographic (EMG) experiment on MH muscle presented in a previous study; and we compare them to the results of a new, similar experiment in order to study the electromyographic activity of MH in typically developing (TD) children and in children with ASD executing grasping-to-eat actions. Our results are remarkably different from the original work and seem to indicate that there is no clear experimental evidence of different action organization in children with ASD.

Critical review of the research leading to the mirror neuron paradigm - biomed 2010.

In this paper, we discuss the research that led to the enunciation of the existence of mirror neurons in monkeys as well as the experiments conducted to confirm the existence of a similar class of neurons in humans. We took into account the necessity that arguments had to be consistent, or at least not in obvious contradiction, with the observations from other disciplines such as psychology, psychiatry, and neurology. The review of the literature has raised many doubts on the mirror neuron system paradigm as proposed by Gallese et al. and Rizzolatti et al. The experimental protocols of the seminal works appear, in our opinion, inadequate for various reasons. From the examination of the literature one can only hypothesize that, in a subject having previous experience of what it is observing, a more or less widespread network of neurons activates in a manner seemingly similar to mirroring in an effort to trying to interpret an action or what happened, or to program or to help to perform an action.