Two Categorical Stages of Object Recognition

Perception ◽  
1978 ◽  
Vol 7 (6) ◽  
pp. 695-705 ◽  
Author(s):  
Elizabeth K Warrington ◽  
Angela M Taylor
Keyword(s):  
Object Recognition ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Perceptual Categorization ◽  
Categorization Task ◽  
Semantic Categorization ◽  
Tentative Model ◽  
The Right

Visual object recognition was investigated in a group of eighty-one patients with right- or left-hemisphere lesions. Two tasks were used, one maximizing perceptual categorization by physical identity, the other maximizing semantic categorization by functional identity. The right-hemisphere group showed impairment on the perceptual categorization task and the left-hemisphere group were impaired on the semantic categorization task. The findings are discussed in terms of categorical stages of object recognition. A tentative model of their cerebral organization is suggested.

Visual Recognition

2005 ◽  
Vol 16 (2) ◽  
pp. 152-160 ◽  
Author(s):  
Kalanit Grill-Spector ◽  
Nancy Kanwisher
Keyword(s):  
Object Recognition ◽  
Exposure Duration ◽  
Visual Recognition ◽  
Natural Images ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Perceptual Categorization ◽  
Identification Task ◽  
Categorization Task ◽  
Processing Steps

What is the sequence of processing steps involved in visual object recognition? We varied the exposure duration of natural images and measured subjects' performance on three different tasks, each designed to tap a different candidate component process of object recognition. For each exposure duration, accuracy was lower and reaction time longer on a within-category identification task (e.g., distinguishing pigeons from other birds) than on a perceptual categorization task (e.g., birds vs. cars). However, strikingly, at each exposure duration, subjects performed just as quickly and accurately on the categorization task as they did on a task requiring only object detection: By the time subjects knew an image contained an object at all, they already knew its category. These findings place powerful constraints on theories of object recognition.

Neuropsychological studies of object recognition

1982 ◽  
Vol 298 (1089) ◽  
pp. 15-33 ◽  
Keyword(s):  
Object Recognition ◽  
Visual Perception ◽  
Visual Impairment ◽  
Right Hemisphere ◽  
Visual Stimuli ◽  
Perceptual Categorization ◽  
Tentative Model ◽  
The Right ◽  
Ground Organization

It is well established that disorders of visual perception are associated with lesions in the right hemisphere. Performances on tasks as disparate as the identification of objects from unusual views or objects drawn so as to overlap, of fragmented letters, of familiar faces, and of anomalous features in drawings, have been shown to be impaired in patients with focal right posterior lesions. A series of investigations are reviewed, directed towards analysing the basis of these deficits. Explanations in terms of primary visual impairment can be rejected, as can an account in terms of faulty figure-ground organization. It is argued that a wide variety of such perceptual deficits - all of which are concerned with meaningful visual stimuli - can be encompassed by the notion of faulty perceptual categorization at an early post-sensory stage of object recognition. Moreover, there is evidence suggesting that some of these various perceptual deficits can be mutually dissociated. The concept of perceptual categorization is discussed in the wider context of a tentative model of object recognition.

scholarly journals Teaching methods shape neural tuning to visual words in beginning readers

2018 ◽  
Author(s):  
Alice van de Walle de Ghelcke ◽  
Bruno Rossion ◽  
Christine Schiltz ◽  
Aliette Lochy
Keyword(s):  
Left Hemisphere ◽  
Teaching Methods ◽  
Right Hemisphere ◽  
Visual Stimulation ◽  
Poor Readers ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Global Method ◽  
Visual Words ◽  
The Impact

AbstractThe impact of global vs. phonics teaching methods for reading on the emergence of left hemisphere neural specialization for word recognition is unknown in children. We tested 42 first graders behaviorally and with electroencephalography with Fast Periodic Visual Stimulation to measure selective neural responses to letter strings. Letter strings were inserted periodically (1/5) in pseudofonts in 40sec sequences displayed at 6Hz and were either words globally taught at school, eliciting visual whole-word form recognition (global method), or control words/pseudowords eliciting grapheme-phoneme mappings (phonic method). Selective responses (F/5, 1.2Hz) were left lateralized for control stimuli but bilateral for globally taught words, especially in poor readers. These results show that global method instruction induces activation in the right hemisphere, involved in holistic processing and visual object recognition, rather than in the specialized left hemisphere for reading. Poor readers, given their difficulties in automatizing grapheme-phoneme mappings, mostly rely on this alternative inadequate strategy.

Visual Object Recognition in Patients with Right-Hemisphere Lesions: Axes or Features?

Perception ◽  
1986 ◽  
Vol 15 (3) ◽  
pp. 355-366 ◽  
Author(s):  
Elizabeth K Warrington ◽  
Merle James
Keyword(s):  
Object Recognition ◽  
Right Hemisphere ◽  
Axial Rotation ◽  
Object Identification ◽  
Threshold Function ◽  
Lesion Group ◽  
Control Group ◽  
Visual Object ◽  
Correct Identification ◽  
Visual Object Recognition

An investigation is reported of the ability of normal subjects and patients with right-hemisphere lesions to identify 3-D shadow images of common objects from different viewpoints. Object recognition thresholds were measured in terms of angle of rotation (through the horizontal or vertical axis) required for correct identification. Effects of axial rotation were very variable and no evidence was found of a typical recognition threshold function relating angle of view to object identification. Although the right-hemisphere-lesion group was consistently and significantly worse than the control group, no qualitative differences between the groups were observed. The findings are discussed in relation to Marr's theory that the geometry of a 3-D shape is derived from axial information, and it is argued that the data reported are more consistent with a distinctive-features model of object recognition.

Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Emotional Responses ◽  
Interactive Effects ◽  
Eeg Activity ◽  
Musical Excerpt ◽  
Major Mode ◽  
Musical Modes ◽  
Slow Tempo ◽  
The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

Developmental Trajectory of Visual Object Recognition Revealed by fMRI

2007 ◽  
Author(s):  
K. Suzanne Scherf ◽  
Marlene Behrmann ◽  
Kate Humphreys ◽  
Beatriz Luna
Keyword(s):  
Object Recognition ◽  
Developmental Trajectory ◽  
Visual Object ◽  
Visual Object Recognition

Dual Intentional Agency

2018 ◽  
Author(s):  
Elizabeth Schechter
Keyword(s):  
Left Hemisphere ◽  
Practical Reasoning ◽  
Right Hemisphere ◽  
Brain Surgery ◽  
Experimental Conditions ◽  
Split Brain ◽  
Intentional Agency ◽  
Intentional Agents ◽  
Experimental Findings ◽  
The Right

This chapter defends the 2-agents claim, according to which the two hemispheres of a split-brain subject are associated with distinct intentional agents. The empirical basis of this claim is that, while both hemispheres are the source or site of intentions, the capacity to integrate them in practical reasoning no longer operates interhemispherically after split-brain surgery. As a result, the right hemisphere-associated agent, R, and the left hemisphere-associated agent, L, enjoy intentional autonomy from each other. Although the positive case for the 2-agents claim is grounded mainly in experimental findings, the claim is not contradicted by what we know of split-brain subjects’ ordinary behavior, that is, the way they act outside of experimental conditions.

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