The temporal dynamics of the effects in occipital cortex of visual-spatial selective attention.

Full Abstract

The temporal dynamics of the effects of lateralized visual selective attention within the lower visual field were studied with the combined application of event-related potentials (ERPs) and positron emission tomography (15O PET). Bilateral stimuli were rapidly presented to the lower visual field while subjects either passively viewed them or covertly attended to a designated side to detect occasional targets. Lateralized attention resulted in strongly enhanced PET activity in contralateral dorsal occipital cortex, while ERPs showed an enhanced positivity (P1 effect, 80-160 ms) for all stimuli (both non-targets and targets) over contralateral occipital scalp. Dipole modeling seeded by the dorsal occipital PET foci yielded an excellent fit for the peak P1 attention effect. However, more detailed ERP modeling throughout the P1 latency window (90-160 ms) suggested a spatial-temporal movement of the attention-related enhancement that roughly paralleled the shape of the dorsal occipital PET attention-related activations-likely reflecting the sequential attention-related enhancement of early visual cortical areas. Lateralized spatial attention also resulted in a longer-latency contralateral enhanced negativity (N2 effect, 230-280 ms) with a highly similar distribution to the earlier P1 effect. Dipole modeling seeded by the same dorsal occipital PET foci also yielded an excellent fit. This pattern of results provides evidence for re-entrance of attention-enhanced activation to the same retinotopically organized region of dorsal extrastriate cortex. Finally, target stimuli in the attended location elicited an additional prolonged enhancement of the longer-latency negativity over contralateral occipital cortex. The combination of PET activation and dipole modeling suggested contribution from a ventral-occipital generator to this target-related activity.

Learn Faster Today Improve your study skills

Author information

Author/s: Woldorff, M G (MG); Liotti, M (M); Seabolt, M (M); Busse, L (L); Lancaster, J L (JL); Fox, P T (PT);

Affiliation: Center for Cognitive Neuroscience, Duke University, Box 90999, Durham, NC 27708-0999, USA. woldorff(-atsign-)duke.edu

Grants: MH 60415 (Agency:NIMH NIH HHS)

Journal and publication information

Publication Type: Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.

Journal: Brain research. Cognitive brain research (Brain Res Cogn Brain Res), published in Netherlands. (Language: eng)

Reference: 2002-Dec; vol 15 (issue 1) : pp 1-15

Dates: Created 2002/11/15; Completed 2003/02/07; Revised 2007/11/14;

PMID: 12433379, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Adolescent
Adult
Attention - physiology
Brain Mapping
Electroencephalography
Evoked Potentials, Visual - physiology
Functional Laterality - physiology
Humans
Magnetic Resonance Imaging - methods

Magnetic Resonance Imaging - methods
Models, Neurological
Occipital Lobe - physiology
Photic Stimulation
Space Perception - physiology
Time Factors
Tomography, Emission-Computed
Visual Fields - physiology
Visual Perception - physiology

These are the highest related articles currently in the database:

See 100+ related articles.