1,721,085 research outputs found
Time-modulated neuronal activity in the premotor cortex of macaque monkeys
No full textA voluntary motor act, executed in response to a stimulus, requires both spatial and temporal computation. Even though electrophysiological and positron emission tomography (PET) investigations on humans suggest that SMA, medial prefrontal cortex and primary motor cortex play a role in temporal mechanisms, we have few data about neuronal time computation in the premotor cortex. The involvement of monkey premotor area (PM) in motor learning and cognitive processes, and the presence of buildup neurons, whose activity is closely related to the motor action, prompted us to investigate the involvement of these set-related neurons in the time domain. To this end we manipulated the duration of a pre-cue in a visuomotor task while recording unit activity. We found that, when the duration of the pre-cue was predictable and long (5 s), delay of the onset of cell activity in consecutive trials gradually increased. On the other hand, when the duration was unpredictable or predictable and short (1 s), this phenomenon could not be detected. The inconsistent discharge correlations with expected reward and attentional processes, and the specific discharge relationship to the time instruction, suggest that these buildup neurons reflect a learning process in the time domain
Une conférence à Berlin
No full textBon L.-C. Une conférence à Berlin. In: Manuel général de l'instruction primaire : journal hebdomadaire des instituteurs. 64e année, tome 33, 1897. pp. 205-206
Les châtiments corporels dans les écoles allemandes
No full textBon L.-C. Les châtiments corporels dans les écoles allemandes. In: La revue pédagogique, tome 32, Janvier-Juin 1898. pp. 59-65
La linea del Piave. Pianura e montagna venete orientali in un secolo di contenziosi attorno all’uso dell’acqua
No full textAuditory-motor and cognitive aspects in area 8B of macaque monkey's frontal cortex: a premotor ear-eye field (PEEF)
No full textIn previous reports, we showed the involvement of area 8B neurons in both spontaneous ear and eye movement and in auditory information processing. Audition-related cells responded to complex environmental stimuli, but not to pure tones, and their activity changed during visual fixation as a possible inhibitory expression of the engagement of attention. We observed auditory, auditory-motor and motor cells for both eye and ear movements. This finding suggests that area 8B may be involved in the integration of auditory input with ear and eye motor output. In this paper, we extended these previous studies by examining area 8B activity in relation to auditive orienting behaviour, as well as the ocular orientation (i.e., visual fixation) studied previously. Visual fixation led to inhibition of activity in auditory and auditory-motor cells, which suggests that attention may be involved in both, maintaining the eye position and reducing the response of these cell types. Accordingly, during a given task or natural behaviour, spatial attention seems to affect more than one sensorimotor channel simultaneously. These data add to our understanding of how the neural network, through a two-channel attentive process, accomplishes to switch between two effectors, namely eyes and ears. Considering the functional, anatomical and cytoarchitectonic differences among the frontal eye field (FEF), the supplementary eye field (SEF) and area 8B, we propose to consider area 8B as a separate premotor ear-eye field (PEEF)
Aspetti della riproduzione e della biometria in Acanthocardia tuberculata (L.) (Bivalvia, Cardiidae) del Golfo di Trieste.
No full textAbstract - Aspects on the reproduction and biometry of Acanthocardia tuberculata (L.)
(Bivalvia, Cardiidae) of the Gulf of Trieste. - In a part of the sampled population of Acanthocardia
tuberculata the sexual maturity occurs in December and the spawning begins in January and extended
to May-June. This length of the spawning and the constant presence of animals in gametogenesis or
mature, implicate different spawning and every individual can participate (o more than one spawning.
The spent stage begins in June and extended to October, but predominates since July in September.
The analysis of some indexes of condition allowed to underline the significative correlations with the
reproductive cycle
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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