The University of Southampton
University of Southampton Institutional Repository

Cognitive evoked potentials during word and picture recognition

Cognitive evoked potentials during word and picture recognition
Cognitive evoked potentials during word and picture recognition

The N400 and P600 components of cognitive evoked potentials or event-related potentials (ERP) are context related and usually recordable after a priming stimulus or context consisting of words or any meaningful stimuli. All studies previous to this one used a sequential presentation of stimuli to elicit the ERPs. In this study, however, the picture and word stimuli were presented simultaneously. ERPs were recorded from 79 neurologically normal subjects including 62 right-handed, 10 left-handed and 7 subjects who were suffering from temporal lobe brain damage. Subjects were either asked to respond as to whether the stimuli were congruent, incongruent or non-sensical (semantic incongruency) or as to whether they were 'new' or 'old' (recognition memory). The number of correct responses and the reaction time were both measured. ERPs were recorded using an electrode cap which consisted of 16-channel scalp electrode montage (an enhanced international 10/20 electrode placement system) with linked mastoids as reference electrodes. Data was acquired and analysed using Neuroscan signal averaging and mapping software.

In all the experimental conditions studied the tasks were performed accurately but reaction time was significantly longer for the incongruent stimuli. The same occurred for 'new' items as opposed to 'old' items. In the ERP recordings the N400 and P600 components were independent. The N400 peak was recorded maximally over the frontal locations while the P600 was mainly a parietal component. Differences were observed in their latency, amplitude and spatial distribution within the various test conditions.

University of Southampton
Sarfarazi, Mehri
edfa46af-24f5-4dc4-9b2e-07abfdc88ca4
Sarfarazi, Mehri
edfa46af-24f5-4dc4-9b2e-07abfdc88ca4

Sarfarazi, Mehri (2000) Cognitive evoked potentials during word and picture recognition. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The N400 and P600 components of cognitive evoked potentials or event-related potentials (ERP) are context related and usually recordable after a priming stimulus or context consisting of words or any meaningful stimuli. All studies previous to this one used a sequential presentation of stimuli to elicit the ERPs. In this study, however, the picture and word stimuli were presented simultaneously. ERPs were recorded from 79 neurologically normal subjects including 62 right-handed, 10 left-handed and 7 subjects who were suffering from temporal lobe brain damage. Subjects were either asked to respond as to whether the stimuli were congruent, incongruent or non-sensical (semantic incongruency) or as to whether they were 'new' or 'old' (recognition memory). The number of correct responses and the reaction time were both measured. ERPs were recorded using an electrode cap which consisted of 16-channel scalp electrode montage (an enhanced international 10/20 electrode placement system) with linked mastoids as reference electrodes. Data was acquired and analysed using Neuroscan signal averaging and mapping software.

In all the experimental conditions studied the tasks were performed accurately but reaction time was significantly longer for the incongruent stimuli. The same occurred for 'new' items as opposed to 'old' items. In the ERP recordings the N400 and P600 components were independent. The N400 peak was recorded maximally over the frontal locations while the P600 was mainly a parietal component. Differences were observed in their latency, amplitude and spatial distribution within the various test conditions.

Text
816924.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (228MB)

More information

Published date: 2000

Identifiers

Local EPrints ID: 464476
URI: http://eprints.soton.ac.uk/id/eprint/464476
PURE UUID: 0b280510-c747-4f03-9c1c-6a23eee34b15

Catalogue record

Date deposited: 04 Jul 2022 23:40
Last modified: 26 Oct 2023 00:56

Export record

Contributors

Author: Mehri Sarfarazi

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×