Biomedical subjects

E L Wilding

Publications and source records attributed to E L Wilding.

22 records · Page 2Linked to original sources

PubMed1997

Event-related potentials and the recognition memory exclusion task.

Subjects heard words that were presented in either a male or a female voice, and were required to perform one of two encoding tasks according to the gender of the voice. At test studied words were presented visually, along with a set of words new to the experiment. Subjects were required to respond on one key to words belonging to one of the two classes of studied word (targets), and to respond on a different key both to words belonging to the other study class (non-targets), and to words new to the experiment. In comparison to the event-related potentials (ERPs) elicited by new words, the ERPs elicited by correctly detected targets exhibited two temporally and topographically distinct positive going effects: one of these was phasic, showed a parietal maximum, and was larger over the left than the right hemisphere. The second effect was more sustained in time, frontally distributed, and was larger over the right hemisphere. The ERPs elicited by correctly classified non-targets contained the parietal effect only. These findings confirm that retrieval of contextual information in tests of recognition memory (recollection) is associated with two distinct ERP modulations. While one of these may be closely tied to process necessary for recollection, the other may reflect less obligatory processes which operate on the products of successful retrieval.

Adolescent↗

PubMed1997

An event-related potential study of memory for words spoken aloud or heard.

Subjects made old/new recognition judgements to visually presented words, half of which had been encountered in a prior study phase. For each word judged old, subjects made a subsequent source judgement, indicating whether they had pronounced the word aloud at study (spoken words), or whether they had heard the word spoken to them (heard words). Event-related potentials (ERPs) were compared for three classes of test item; words correctly judged to be new (correct rejections), and spoken and heard words that were correctly assigned to source (spoken hit/hit and heard hit/hit response categories). Consistent with previous findings (Wilding, E. L. and Rugg, M. D., Brain, 1996, 119, 889-905), two temporally and topographically dissociable components, with parietal and frontal maxima respectively, differentiated the ERPs to the hit/hit and correct rejection response categories. In addition, there was some evidence that the frontally distributed component could be decomposed into two distinct components, only one of which differentiated the two classes of hit/hit ERPs. The findings suggest that at least three functionally and neurologically dissociable processes can contribute to successful recovery of source information.

Adolescent↗

PubMed1996

An event-related potential study of recognition memory with and without retrieval of source.

Event-related potentials (ERPs) were recorded during the test phase of a recognition memory task in two experiments. In both experiments subjects made initial old/new judgements to visually presented words, and for words judged old, indicated in which of two voices (male/female) the words had been heard at study. In the second experiment only subjects had the option to signal that they were uncertain about the status of a test word. Two positive-going ERP effects differentiated the ERPs evoked by correctly recognized old words from those evoked by words correctly judged new. The two effects differed in their scalp topography and time course, and were both of greater magnitude in the ERPs evoked by recognized words for which a correct voice judgement was made. The findings are consistent with the view that multiple neural systems underlie the ability to recognize an item and to recall its study context. However, the findings offer little support for the view, articulated in certain 'dual-process' models of recognition memory, that recognition judgements with and without retrieval of study context depend upon qualitatively different memory processes or systems.

Analysis of Variance↗

PubMed1995

Recognition memory with and without retrieval of context: an event-related potential study.

In two recognition memory tests subjects made initial old/new judgements and subsequently judged whether 'old' words had been presented auditorily or visually at study. Test words were presented visually in Experiment 1 and auditorily in Experiment 2. ERPs evoked at test by words correctly judged 'old' were separated according to whether they were correctly or incorrectly assigned to their study modality. In both experiments, ERPs to correctly assigned words were more positive than those evoked by words correctly judged to be new. This ERP old/new effect was absent for words incorrectly assigned to study modality in Experiment 1, and was observed over a restricted latency range in Experiment 2. The findings are consistent with the hypothesis that the old/new effect is associated with recognition memory based on recollection of the study episode, rather than familiarity.

Acoustic Stimulation↗