1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia

Opción 1: Descargar recurso

Opción 2: Descargar recurso

Detalles del recurso


Our vision is as yet unsurpassed by machines because of the sophisticated representations of objects in our brains. This representation is vastly different from a pixel-based representation used in machine storages. It is this sophisticated representation that enables us to perceive two faces as very different, i.e, they are far apart in the “perceptual space”, even though they are close to each other in their pixel-based representations. Neuroscientists have proposed distances between responses of neurons to the images (as measured in macaque monkeys) as a quantification of the “perceptual distance” between the images. Let us call these neuronal dissimilarity indices of perceptual distances. They have also proposed behavioural experiments to quantify these perceptual distances. Human subjects are asked to identify, as quickly as possible, an oddball image embedded among multiple distractor images. The reciprocal of the search times for identifying the oddball is taken as a measure of perceptual distance between the oddball and the distractor. Let us call such estimates as behavioural dissimilarity indices. In this thesis, we describe a decision-theoretic model for visual search that suggests a connection between these two notions of perceptual distances. In the first part of the thesis, we model visual search as an active sequential hypothesis testing problem. Our analysis suggests an appropriate neuronal dissimilarity index which correlates strongly with the reciprocal of search times. We also consider a number of alternative possibilities such as relative entropy (Kullback-Leibler divergence), the Chernoff entropy and the L1-distance associated with the neuronal firing rate profiles. We then come up with a means to rank the various neuronal dissimilarity indices based on how well they explain the behavioural observations. Our proposed dissimilarity index does better than the other three, followed by relative entropy, then Chernoff entropy and then L1 distance. In the second part of the thesis, we consider a scenario where the subject has to find an oddball image, but without any prior knowledge of the oddball and distractor images. Equivalently, in the neuronal space, the task for the decision maker is to find the image that elicits firing rates different from the others. Here, the decision maker has to “learn” the underlying statistics and then make a decision on the oddball. We model this scenario as one of detecting an odd Poisson point process having a rate different from the common rate of the others. The revised model suggests a new neuronal dissimilarity index. The new dissimilarity index is also strongly correlated with the behavioural data. However, the new dissimilarity index performs worse than the dissimilarity index proposed in the first part on existing behavioural data. The degradation in performance may be attributed to the experimental setup used for the current behavioural tasks, where search tasks associated with a given image pair were sequenced one after another, thereby possibly cueing the subject about the upcoming image pair, and thus violating the assumption of this part on the lack of prior knowledge of the image pairs to the decision maker. In conclusion, the thesis provides a framework for connecting the perceptual distances in the neuronal and the behavioural spaces. Our framework can possibly be used to analyze the connection between the neuronal space and the behavioural space for various other behavioural tasks.

Pertenece a

ETD at Indian Institute of Science  


Vaidhiyan, Nidhin Koshy - 

Id.: 70101338

Idioma: inglés (Estados Unidos)  - 

Versión: 1.0

Estado: Final

Palabras claveSequential Detection - 

Tipo de recurso: Thesis  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Requerimientos técnicos:  Browser: Any - 

Relación: [References] G27253

Fecha de contribución: 24-sep-2017



Otros recursos que te pueden interesar

  1. CIL 9.5438 – Record of ‘collegia’ who helped fund the repaving of the cattle market in Falerio Squeeze and photograph
  2. T-type calcium channels in rat carotid body chemoreceptor cells. Molecular and functional hallmarks Resumen del póster presentado al 14th International Meeting of the European Calcium Society, celebra...
  3. Orai1 and Stim1 downregulation mediates the loss of store-operated Ca2+ entry in rat hippocampal neurons aged in vitro Resumen del póster presentado al 14th International Meeting of the European Calcium Society, celebra...
  4. Aging and amyloid β oligomers enhance TLR4 expression and are required for LPS-induced Ca2+ responses and neuron cell death in rat hippocampal neurons Resumen del póster presentado al 14th International Meeting of the European Calcium Society, celebra...
  5. In vivo Ca2+ imaging in the endoplasmic reticulum with GAP sensors Resumen del trabajo presentado al 14th International Meeting of the European Calcium Society, celebr...

Otros recursos de la mismacolección

  1. Integrated Interfaces for Sensing Applications Sensor interfaces are needed to communicate the measured real-world analog values to the base¬band d...
  2. Network Coding for Wirless Relaying and Wireline Networks Network coding has emerged as an attractive alternative to routing because of the through put improv...
  3. Timbre Perception of Time-Varying Signals Every auditory event provides an information-rich signal to the brain. The signal constitutes percep...
  4. Packet Scheduling on the Wireless Channel Scheduling has always been an indispensable part of resource allocation in wireless networks. Accura...
  5. Photonic Crystal Ring Resonators for Optical Networking and Sensing Applications Photonic bandgap structures have provided promising platform for miniaturization of modern integrate...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.