17 research outputs found
Optical neuron using polarisation switching in a 1550nm-VCSEL
We report a new approach to mimic basic functionalities of a neuron using a 1550 nm Vertical Cavity Surface Emitting Laser (VCSEL) which is based on the polarisation switching (PS) that can be induced in these devices when subject to polarised optical injection. Positive and negative all-optical threshold operations are demonstrated experimentally using external optical injection into the two orthogonal polarizations of the fundamental transverse mode. The polarisation of the light emitted by the device is used to determine the state of the VCSEL-Neuron, active (orthogonal) or inactive (parallel). This approach forms a new way to reproduce optically the response of a neuron to an excitatory and an inhibitory stimulus. © 2010 Optical Society of America
Caracterização fitossociológica de um remanescente de Floresta Ombrófila mista em Guarapuava, PR
Assessing Symmetry by Comparing the Acquisition of Symmetric and Nonsymmetric Conditional Relations in a Capuchin Monkey
The present study presents a procedure to assess the property of symmetry
by comparing the acquisition of conditional relations that are consistent and
inconsistent with this property in a capuchin monkey (Sapajus spp.). One young
male monkey underwent arbitrary matching-to-sample training. The experiment had
four phases: Phase 1.1 (establishing A1B1 and A2B2 relations), Phase 1.2
(reinforcing B1A1 and B2A2 relations, consistent with the property of symmetry),
Phase 2.1 (establishing A3B3 and A4B4 relations), and Phase 2.2 (reinforcing B3A4
and B4A3 relations, inconsistent with the property of symmetry). A comparison
between Phase 1.2 (consistent) and Phase 2.2 (inconsistent) showed faster
acquisition of consistent relations (B1A1 and B2A2) than inconsistent relations
(B3A4 and B4A3). The results suggest that the established conditional
discriminations may have the property of symmetry and confirm the potential of
comparative analysis between the acquisition of conditional discriminations as a
promising procedure to evaluate equivalence class formation in nonhuman
subjects
Assessing Symmetry by Comparing the Acquisition of Symmetric and Nonsymmetric Conditional Relations in a Capuchin Monkey
The present study presents a procedure to assess the property of symmetry by comparing the acquisition of conditional relations that are consistent and inconsistent with this property in a capuchin monkey (Sapajus spp.). One young male monkey underwent arbitrary matching-to-sample training. The experiment had four phases: Phase 1.1 (establishing A1B1 and A2B2 relations), Phase 1.2 (reinforcing B1A1 and B2A2 relations, consistent with the property of symmetry), Phase 2.1 (establishing A3B3 and A4B4 relations), and Phase 2.2 (reinforcing B3A4 and B4A3 relations, inconsistent with the property of symmetry). A comparison between Phase 1.2 (consistent) and Phase 2.2 (inconsistent) showed faster acquisition of consistent relations (B1A1 and B2A2) than inconsistent relations (B3A4 and B4A3). The results suggest that the established conditional discriminations may have the property of symmetry and confirm the potential of comparative analysis between the acquisition of conditional discriminations as a promising procedure to evaluate equivalence class formation in nonhuman subjects