Temporal and Spectral Patterns Related to Texture Discrimination

FERNANDO DANIEL FARFÁN; ANA LÍA ALBARRACÍN; CARMELO JOSÉ FELICE

Huerta Grande - Cordoba

Congreso; II Reunion Conjunta de Neurociencias; 2010

Sociedad Argentina de Investigación en Neurociencias

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> This work explores the existence of news temporal and spectral patterns related to texture neural code. For this, we analyzed the multifiber afferent discharge of one vibrissal nerve during active whisking in anesthetized rats. We used sandpapers of different grain size as roughness discrimination surfaces. We have proposed two new methods for afferent activity analysis: a Time-Frequency (TF) analysis and Inter-event Time (IET) analysis. The last analysis allowed us to relate the electrophysiological activity with the physical characteristics of friction surfaces. For this, we also obtained three parameters that characterized the roughness surfaces: arithmetical deviation of assessed profile (Ra), average maximum height of profile (Rz) and distance between local peaks (DBLP). The TF analysis shows that smooth textures evoke lower frequency in the multifiber activity than rougher texture when differences are deemed significant. The IET analysis allows us extracting temporal patterns or 'events' related to texture discrimination coding. Finally, we concluded that temporal patterns found in the multifiber activity of a single vibrissa innervation would be related with the texture coding and that the DBLP would be the better parameter described by these patterns.