Abstract
The relationship of task relevance and stimulus probability to P300 morphology, latency and distribution was assessed. Eight year olds and adults completed visual oddball tasks of recognition memory with frequent non- target (60%), infrequent target (20%), and infrequent novel (20%) stimuli. Stimuli consisted of 2 female faces posing neutral expressions, and 40 trial unique novel photographs depicting scenes, animals, objects or abstract patterns. Event-related potentials were recorded from 17 electrodes over frontal, central and parietal scalp, including lateral temporal sites. All stimuli elicited P300 responses at parietal electrodes, with the largest responses to the target stimuli (relevant and infrequent). The P300 responses of adults and children were morphologically dissimilar, with children showing broader peaks and latency shifts across electrodes. In addition, the eight year olds displayed a frontal negativity to novel stimuli which was absent in the responses of adult participants. Results suggest that different anatomical or functional circuitry may be involved in the processing of novelty for adults as compared to eight year olds.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 294-308 |
| Number of pages | 15 |
| Journal | Electroencephalography and clinical neurophysiology |
| Volume | 98 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1996 |
Bibliographical note
Funding Information:Electrophysiological techniques have long been employed to examine the neurological underpinnings of various perceptual and cognitive phenomena. For example, Donchin et al. (1986) have described how electrophysiological measures permit one to obtain information about human information processing that is not easily or at all available in the traditional subjective and performance measures of psychological research (e.g., mental chronometry). Scalp electrical activity is recorded from an individual engaged in some perceptual or cognitive task. The resultant signals are averaged to give an estimate of the proportion of the voltage that is time-locked to a particular event, usually the presentation of an external stimulus (Donchin et al., 1986). This event-related potential (ERP) * Corresponding author. E-mail: [email protected]. Support for this research came from a National Institutes of Health (NIH) training grant to the Center for Research in Learning, Perception, and Cognition, University of Minnesota (HD07151) and grants from the National Institute of Mental Health (MH46860) and the National Institutes of Health (NS32976) to the second author.
Keywords
- Electrophysiological response
- P300
- Stimulus probability
- Task relevance
- Visual stimulus novelty