Fingerprints of Learned Object Recognition Seen in the fMRI Activation Patterns of Lateral Occipital Complex

An important characteristic of visual perception is the fact that object recognition is largely immune to changes in viewing conditions. This invariance is obtained within a sequence of ventral stream visual areas beginning in area V1 and ending in high order occipito-temporal object areas (the lateral occipital complex, LOC). Here we studied whether this transformation could be observed in the contrast response of these areas. Subjects were presented with line drawings of common objects and faces in five different contrast levels (0, 4, 6, 10, and 100%). Our results show that indeed there was a gradual trend of increasing contrast invariance moving from area V1, which manifested high sensitivity to contrast changes, to the LOC, which showed a significantly higher degree of invariance at suprathreshold contrasts (from 10 to 100%). The trend toward increased invariance could be observed for both face and object images; however, it was more complete for the face images, while object images still manifested substantial sensitivity to contrast changes. Control experiments ruled out the involvement of attention effects or hemodynamic “ceiling” in producing the contrast invariance. The transition from V1 to LOC was gradual with areas along the ventral stream becoming increasingly contrast-invariant. These results further stress the hierarchical and gradual nature of the transition from early retinotopic areas to high order ones, in the build-up of abstract object representations.

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Integrated Contextual Representation for Objects' Identities and Their Locations

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2008.20027 ◽

2008 ◽

Vol 20 (3) ◽

pp. 371-388 ◽

Cited By ~ 57

Author(s):

Nurit Gronau ◽

Maital Neta ◽

Moshe Bar

Keyword(s):

Object Recognition ◽

Semantic Processing ◽

Contextual Information ◽

Reaction Times ◽

Brain Regions ◽

Target Object ◽

Interactive Effects ◽

Attention And Memory ◽

Contextual Knowledge ◽

Lateral Occipital Complex

Visual context plays a prominent role in everyday perception. Contextual information can facilitate recognition of objects within scenes by providing predictions about objects that are most likely to appear in a specific setting, along with the locations that are most likely to contain objects in the scene. Is such identity-related (“semantic”) and location-related (“spatial”) contextual knowledge represented separately or jointly as a bound representation? We conducted a functional magnetic resonance imaging (fMRI) priming experiment whereby semantic and spatial contextual relations between prime and target object pictures were independently manipulated. This method allowed us to determine whether the two contextual factors affect object recognition with or without interacting, supporting a unified versus independent representations, respectively. Results revealed a Semantic × Spatial interaction in reaction times for target object recognition. Namely, significant semantic priming was obtained when targets were positioned in expected (congruent), but not in unexpected (incongruent), locations. fMRI results showed corresponding interactive effects in brain regions associated with semantic processing (inferior prefrontal cortex), visual contextual processing (parahippocampal cortex), and object-related processing (lateral occipital complex). In addition, activation in fronto-parietal areas suggests that attention and memory-related processes might also contribute to the contextual effects observed. These findings indicate that object recognition benefits from associative representations that integrate information about objects' identities and their locations, and directly modulate activation in object-processing cortical regions. Such context frames are useful in maintaining a coherent and meaningful representation of the visual world, and in providing a platform from which predictions can be generated to facilitate perception and action.

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Characterizing the response to face pareidolia in human category-selective visual cortex

10.1101/233387 ◽

2017 ◽

Cited By ~ 4

Author(s):

Susan G Wardle ◽

Kiley Seymour ◽

Jessica Taubert

Keyword(s):

Face Detection ◽

Temporal Cortex ◽

Visual Features ◽

Activation Patterns ◽

Lateral Occipital Complex ◽

Face Area ◽

Visual Areas ◽

Ventral Pathway ◽

High Level ◽

Visual Properties

AbstractThe neural mechanisms underlying face and object recognition are understood to originate in ventral occipital-temporal cortex. A key feature of the functional architecture of the visual ventral pathway is its category-selectivity, yet it is unclear how category-selective regions process ambiguous visual input which violates category boundaries. One example is the spontaneous misperception of faces in inanimate objects such as the Man in the Moon, in which an object belongs to more than one category and face perception is divorced from its usual diagnostic visual features. We used fMRI to investigate the representation of illusory faces in category-selective regions. The perception of illusory faces was decodable from activation patterns in the fusiform face area (FFA) and lateral occipital complex (LOC), but not from other visual areas. Further, activity in FFA was strongly modulated by the perception of illusory faces, such that even objects with vastly different visual features were represented similarly if all images contained an illusory face. The results show that the FFA is broadly-tuned for face detection, not finely-tuned to the homogenous visual properties that typically distinguish faces from other objects. A complete understanding of high-level vision will require explanation of the mechanisms underlying natural errors of face detection.

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The role of posterior ventral stream areas for viewpoint-invariant object recognition

10.1101/2021.07.07.451407 ◽

2021 ◽

Author(s):

Sophia Nestmann ◽

Hans-Otto Karnath ◽

Johannes Rennig

Keyword(s):

Object Recognition ◽

Object Perception ◽

Ventral Stream ◽

Visual Object ◽

Visual Stream ◽

Activation Patterns ◽

Object Constancy ◽

Invariant Object Recognition ◽

Fmri Experiment ◽

The Right

Object constancy is one of the most crucial mechanisms of the human visual system enabling viewpoint invariant object recognition. However, the neuronal foundations of object constancy are widely unknown. Research has shown that the ventral visual stream is involved in processing of various kinds of object stimuli and that several regions along the ventral stream are possibly sensitive to the orientation of an object in space. To systematically address the question of viewpoint sensitive object perception, we conducted a study with stroke patients as well as an fMRI experiment with healthy participants applying object stimuli in several spatial orientations, for example in typical and atypical viewing conditions. In the fMRI experiment, we found stronger BOLD signals and above-chance classification accuracies for objects presented in atypical viewing conditions in fusiform face sensitive and lateral occipito-temporal object preferring areas. In the behavioral patient study, we observed that lesions of the right fusiform gyrus were associated with lower performance in object recognition for atypical views. The complementary results from both experiments emphasize the contributions of fusiform and lateral-occipital areas to visual object constancy and indicate that visual object constancy is particularly enabled through increased neuronal activity and specific activation patterns for objects in demanding viewing conditions.

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Activation patterns in multiple sclerosis on the Computerized Tests of Information Processing

Yearbook of Neurology and Neurosurgery ◽

10.1016/j.yneu.2012.04.009 ◽

2012 ◽

Vol 2012 ◽

pp. 72-73

Author(s):

A. Minagar

Keyword(s):

Multiple Sclerosis ◽

Information Processing ◽

Activation Patterns ◽

Computerized Tests

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Use It and Still Lose It?

GeroPsych ◽

10.1024/1662-9647/a000020 ◽

2010 ◽

Vol 23 (3) ◽

pp. 169-175 ◽

Cited By ~ 14

Author(s):

Adrian Schwaninger ◽

Diana Hardmeier ◽

Judith Riegelnig ◽

Mike Martin

Keyword(s):

Object Recognition ◽

Cognitive Development ◽

Recognition Test ◽

Cognitive Aging ◽

Recognition Task ◽

Airport Security ◽

Visual Object ◽

Long Term Effects ◽

Object Recognition Test ◽

X Ray

In recent years, research on cognitive aging increasingly has focused on the cognitive development across middle adulthood. However, little is still known about the long-term effects of intensive job-specific training of fluid intellectual abilities. In this study we examined the effects of age- and job-specific practice of cognitive abilities on detection performance in airport security x-ray screening. In Experiment 1 (N = 308; 24–65 years), we examined performance in the X-ray Object Recognition Test (ORT), a speeded visual object recognition task in which participants have to find dangerous items in x-ray images of passenger bags; and in Experiment 2 (N = 155; 20–61 years) in an on-the-job object recognition test frequently used in baggage screening. Results from both experiments show high performance in older adults and significant negative age correlations that cannot be overcome by more years of job-specific experience. We discuss the implications of our findings for theories of lifespan cognitive development and training concepts.

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Effects of Psychotherapy on Brain Activation Patterns in Anxiety Disorders

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000240 ◽

2016 ◽

Vol 224 (2) ◽

pp. 62-70 ◽

Cited By ~ 2

Author(s):

Thomas Straube

Keyword(s):

Anxiety Disorders ◽

Neuronal Plasticity ◽

Functional Neuroimaging ◽

State Of The Art ◽

Methodological Issues ◽

Future Directions ◽

Activation Patterns ◽

New Learning ◽

Analytical Strategies ◽

Sample Characteristics

Abstract. Psychotherapy is an effective treatment for most mental disorders, including anxiety disorders. Successful psychotherapy implies new learning experiences and therefore neural alterations. With the increasing availability of functional neuroimaging methods, it has become possible to investigate psychotherapeutically induced neuronal plasticity across the whole brain in controlled studies. However, the detectable effects strongly depend on neuroscientific methods, experimental paradigms, analytical strategies, and sample characteristics. This article summarizes the state of the art, discusses current theoretical and methodological issues, and suggests future directions of the research on the neurobiology of psychotherapy in anxiety disorders.

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