Object categorization in finer levels requires higher spatial frequencies, and therefore takes longer

by   Matin N. Ashtiani, et al.

The human visual system contains a hierarchical sequence of modules that take part in visual perception at different levels of abstraction, i.e., superordinate, basic, and subordinate levels. One important question is to identify the "entry" level at which the visual representation is commenced in the process of object recognition. For a long time, it was believed that the basic level had advantage over two others; a claim that has been challenged recently. Here we used a series of psychophysics experiments, based on a rapid presentation paradigm, as well as two computational models, with bandpass filtered images to study the processing order of the categorization levels. In these experiments, we investigated the type of visual information required for categorizing objects in each level by varying the spatial frequency bands of the input image. The results of our psychophysics experiments and computational models are consistent. They indicate that the different spatial frequency information had different effects on object categorization in each level. In the absence of high frequency information, subordinate and basic level categorization are performed inaccurately, while superordinate level is performed well. This means that, low frequency information is sufficient for superordinate level, but not for the basic and subordinate levels. These finer levels require high frequency information, which appears to take longer to be processed, leading to longer reaction times. Finally, to avoid the ceiling effect, we evaluated the robustness of the results by adding different amounts of noise to the input images and repeating the experiments. As expected, the categorization accuracy decreased and the reaction time increased significantly, but the trends were the same.This shows that our results are not due to a ceiling effect.


page 4

page 7


How Deep is the Feature Analysis underlying Rapid Visual Categorization?

Rapid categorization paradigms have a long history in experimental psych...

Basic-level categorization of intermediate complexity fragments reveals top-down effects of expertise in visual perception

Visual expertise is usually defined as the superior ability to distingui...

WaveTransform: Crafting Adversarial Examples via Input Decomposition

Frequency spectrum has played a significant role in learning unique and ...

What takes the brain so long: Object recognition at the level of minimal images develops for up to seconds of presentation time

Rich empirical evidence has shown that visual object recognition in the ...

Early Salient Region Selection Does Not Drive Rapid Visual Categorization

The current dominant visual processing paradigm in both human and machin...

Multi-Granular Text Encoding for Self-Explaining Categorization

Self-explaining text categorization requires a classifier to make a pred...

Please sign up or login with your details

Forgot password? Click here to reset