Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 11356379

Event-related potentials from a visual categorization task.

A Antal·S Kéri·G Kovács·P Liszli·Z Janka·G Benedek
View original source ↗Export metadata ↓

Abstract

Investigation of the neural bases of human perceptual categorization is a continuously growing territory of visual sciences. Recently, several papers appeared on the cortical bases of human categorization performance, using functional brain imaging techniques such as positron emission tomography (PET) or functional magnetic resonance imaging (fMRI). However, the cheaper commercially available laboratory tests are not always the best methods to study multiple aspects of visual categorization. In this study, we describe the electrophysiological correlates of natural scene categorization in humans. The subject's task was to decide whether briefly presented natural scenes contained animal or non-animal items. Analysis of event-related potentials (ERPs) recorded during the categorization task, revealed more negative potentials for non-animal stimuli (NAS) in the time windows of 150-250 ms (N1) and 350-500 ms (N2), and more positive potentials for animal stimuli (AS) in the time window of 250-350 ms (P2). Our work provides an inexpensive noninvasive method to study both early perceptual and late phases of semantic information processing by recording ERPs during the categorization of natural scenes.

Explore related subjects

Evoked Potentials, VisualHumansNeurophysiologyPhotic StimulationVisual PerceptionJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Antal, S Kéri, G Kovács, P Liszli, Z Janka, G Benedek. 2001. Event-related potentials from a visual categorization task.. https://doi.org/10.1016/s1385-299x(01)00055-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Isolated absence of optic chiasm revealed by congenital nystagmus, MRI and VEPs.

Congenital nystagmus is a rare condition mainly characterised by rhythmic, conjugate, and horizontal oscillations of both eyes that persist in the vertical gaze. This disorder is usually noticed in the neonatal period and persists throughout life. It can be of sensory origin, associated with low visual acuity of various causes, or of motor origin, caused by a defect in the slow eye movement system. The former can be genetically determined. It can also be associated with several conditions, the most frequent being albinism. The achiasma syndrome has recently been recognized in two patients as an autosomal recessive inherited cause of congenital nystagmus. We report the case of the so far youngest reported baby having been diagnosed with the isolated achiasmatic condition, which presented with congenital nystagmus and see-saw nystagmus, and discuss its clinical findings and 18 months follow-up. The achiasmatic syndrome should be included in the differential diagnosis of congenital nystagmus, as all the described cases presented like that. Complete investigations should be performed to allow the best evolution and follow-up of these children.

Evoked Potentials, Visual↗
PubMed2002

[Autoregressive analysis of flash evoked potentials in healthy preterm infants during sleep].

To interpret the flash evoked potential (FVEP) as dynamic high-order responses to natural and experimental stimulation in healthy preterm infants, waveform analysis of FVEP in 36 healthy preterm infants (postconceptional age 28~42 weeks) were performed using an autoregressive analysis. Based on the histogram of damping frequency of different component impulse response waveforms, the waveforms were divided into 4 groups: group I (0 ~ <2 Hz), group II (2 ~ <6.5 Hz), group III (6.5 ~ <12.0 Hz) and group IV (12~25 Hz). The total power, power of component impulse responses (group I~IV), and damping time (group II~IV) changed significantly with increasing postconceptional age (P<0.01 or P<0.05). Identification of an impulse response component with dominant frequency which undergoes a well-identified change with age is considered to be a useful tool for discriminating between normal and abnormal changes in the FVEP with age in healthy preterm infants.

Evoked Potentials, Visual↗
PubMed2002

How distributed is visual category information in human occipito-temporal cortex? An fMRI study.

We used fMRI to study the distribution of object category information in the ventral visual pathway. Extending the findings of, we find that categories of stimuli can be distinguished by the pattern of activation they elicit across this entire pathway, even when the stimuli within a category differ in viewpoint, exemplar, or image format. However, regions within the ventral visual pathway are neither interchangeable nor equipotential. Although the FFA and PPA permit excellent discrimination between preferred versus nonpreferred stimuli (e.g., faces-bottles and houses-bottles, respectively), we find that neither region alone permits accurate discrimination between pairs of nonpreferred stimuli (e.g., bottles-shoes). These findings indicate that the ventral visual pathway is not homogeneous, but contains some regions (including FFA and PPA) that are primarily involved in the analysis of a single class of stimulus.

Evoked Potentials, Visual↗