scholarly journals The influence of object identity on lightness constancy

2010 ◽  
Vol 8 (6) ◽  
pp. 566-566
Author(s):  
S. Zdravkovic
Keyword(s):  
Object Identity ◽  
Lightness Constancy

scholarly journals Lightness constancy: Object identity and temporal integration

Psihologija ◽  
2008 ◽  
Vol 41 (1) ◽  
pp. 5-20 ◽  
Author(s):  
Suncica Zdravkovic
Keyword(s):  
Prior Experience ◽  
Temporal Integration ◽  
Illumination Level ◽  
Object Identity ◽  
Single Object ◽  
Lightness Constancy ◽  
Systematic Fashion ◽  
Target Values ◽  
Priming Paradigm ◽  
True Color

Studies of lightness constancy typically involve the comparison of two objects of the same shade that have been placed under different illuminations. In this study, we introduce factors such as object identity and immediate prior experience to measure the effect of these manipulations on constancy. In the first experiment, conditions sufficient to reproduce classical constancy failure (illumination difference, target values, articulation level) were determined. In the second experiment a lightness judgment was made for a gray target that was then seen to move into another illumination level for the second match. Motion was used in an attempt to stress the target?s identity. The shade was still judged significantly lighter when placed under the higher than under the lower illumination. Failure of constancy thus occurred even when object identity was not in question. In the third experiment a priming paradigm was used, to assess the strength of constancy: one shade would appear in one illumination level and another shade in the other illumination level. Motion was used to trick observers into thinking that only a single object was presented. The estimated shade varied as a function of the shade of the prime. In the last experiment, observers were asked to make another match when the object was removed from view: the match of its true color independent of illumination. The value of this match-from-memory was based on the value obtained in the higher illumination level. Taken together, the experiments show that through object identity, immediate prior experience can influence lightness in systematic fashion.

scholarly journals Right fusiform response patterns reflect visual object identity rather than semantic similarity

NeuroImage ◽  
2013 ◽  
Vol 83 ◽  
pp. 87-97 ◽  
Author(s):  
Rose Bruffaerts ◽  
Patrick Dupont ◽  
Sophie De Grauwe ◽  
Ronald Peeters ◽  
Simon De Deyne ◽  
...  
Keyword(s):  
Semantic Similarity ◽  
Visual Object ◽  
Response Patterns ◽  
Object Identity

Conversion of object identity to object-general semantic value in the primate temporal cortex

Science ◽  
2017 ◽  
Vol 357 (6352) ◽  
pp. 687-692 ◽  
Author(s):  
Keita Tamura ◽  
Masaki Takeda ◽  
Rieko Setsuie ◽  
Tadashi Tsubota ◽  
Toshiyuki Hirabayashi ◽  
...  
Keyword(s):  
Temporal Cortex ◽  
Object Identity ◽  
Semantic Value ◽  
General Semantic

scholarly journals Object comparison in the lateral intraparietal area

2017 ◽  
Vol 118 (4) ◽  
pp. 2458-2469 ◽  
Author(s):  
Wei Song Ong ◽  
Koorosh Mirpour ◽  
James W. Bisley
Keyword(s):  
Prefrontal Cortex ◽  
Object Recognition ◽  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Ventral Stream ◽  
Object Identity ◽  
Stimulus Similarity ◽  
Lateral Intraparietal Area ◽  
Dynamic Representation ◽  
And Task

We can search for and locate specific objects in our environment by looking for objects with similar features. Object recognition involves stimulus similarity responses in ventral visual areas and task-related responses in prefrontal cortex. We tested whether neurons in the lateral intraparietal area (LIP) of posterior parietal cortex could form an intermediary representation, collating information from object-specific similarity map representations to allow general decisions about whether a stimulus matches the object being looked for. We hypothesized that responses to stimuli would correlate with how similar they are to a sample stimulus. When animals compared two peripheral stimuli to a sample at their fovea, the response to the matching stimulus was similar, independent of the sample identity, but the response to the nonmatch depended on how similar it was to the sample: the more similar, the greater the response to the nonmatch stimulus. These results could not be explained by task difficulty or confidence. We propose that LIP uses its known mechanistic properties to integrate incoming visual information, including that from the ventral stream about object identity, to create a dynamic representation that is concise, low dimensional, and task relevant and that signifies the choice priorities in mental matching behavior. NEW & NOTEWORTHY Studies in object recognition have focused on the ventral stream, in which neurons respond as a function of how similar a stimulus is to their preferred stimulus, and on prefrontal cortex, where neurons indicate which stimulus is being looked for. We found that parietal area LIP uses its known mechanistic properties to form an intermediary representation in this process. This creates a perceptual similarity map that can be used to guide decisions in prefrontal areas.

scholarly journals Object manifold geometry across the mouse cortical visual hierarchy

2020 ◽  
Author(s):  
Emmanouil Froudarakis ◽  
Uri Cohen ◽  
Maria Diamantaki ◽  
Edgar Y. Walker ◽  
Jacob Reimer ◽  
...  
Keyword(s):  
Home Cage ◽  
Object Representations ◽  
Object Identity ◽  
Population Code ◽  
Neuronal Populations ◽  
Linear Separability ◽  
Visual Hierarchy ◽  
Visual Areas ◽  
Invariant Object Recognition ◽  
Object Coding

AbstractDespite variations in appearance we robustly recognize objects. Neuronal populations responding to objects presented under varying conditions form object manifolds and hierarchically organized visual areas are thought to untangle pixel intensities into linearly decodable object representations. However, the associated changes in the geometry of object manifolds along the cortex remain unknown. Using home cage training we showed that mice are capable of invariant object recognition. We simultaneously recorded the responses of thousands of neurons to measure the information about object identity available across the visual cortex and found that lateral visual areas LM, LI and AL carry more linearly decodable object identity information compared to other visual areas. We applied the theory of linear separability of manifolds, and found that the increase in classification capacity is associated with a decrease in the dimension and radius of the object manifold, identifying features of the population code that enable invariant object coding.

scholarly journals Lightness constancy in 4-month-old infants: With and without a white anchoring point cue

2002 ◽  
Vol 2 (10) ◽  
pp. 50-50
Author(s):  
S. H.-L. Chien ◽  
K. W. Bronson-Castain
Keyword(s):  
Lightness Constancy
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