Biomedical subjects

Geoff Ward

Publications and source records attributed to Geoff Ward.

7 recordsLinked to original sources

PubMed2006

Examining the relationship between free recall and immediate serial recall: the effect of concurrent task performance.

In 3 experiments, participants saw lists of 16 words for free recall with or without a 6-digit immediate serial recall (ISR) task after each word. Free recall was performed under standard visual silent and spoken-aloud conditions (Experiment 1), overt rehearsal conditions (Experiment 2), and fixed rehearsal conditions (Experiment 3). The authors found that in each experiment, there was no effect of ISR on the magnitude of the recency effect, but interleaved ISR disrupted free recall of those words that would otherwise be rehearsed. The authors conclude that ISR and recency cannot both be outputs from a unitary limited-capacity short-term memory store and discuss the possibility that the process of rehearsal may be common to both tasks.

Acoustic Stimulation↗

PubMed2005

Age-related deficits in free recall: the role of rehearsal.

Age-related deficits have been consistently observed in free recall. Recent accounts of episodic memory suggest that these deficits could result from differential patterns of rehearsal. In the present study, 20 young and 20 older adults (mean ages 21 and 72 years, respectively) were presented with lists of 20 words for immediate free recall using the overt rehearsal methodology. The young outperformed the older adults at all serial positions. There were significant age-related differences in the patterns of overt rehearsals: Young adults rehearsed a greater number of different words than did older adults, they rehearsed words to more recent serial positions, and their rehearsals were more widely distributed throughout the list. Consistent with a recency-based account of episodic memory, age deficits in free recall are largely attributable to age differences in the recency, frequency, and distribution of rehearsals.

Adult↗

PubMed2004

The effect of the length of to-be-remembered lists and intervening lists on free recall: a reexamination using overt rehearsal.

In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists and had to recall the list prior to that last presented list. In Experiment 3, either 1 or 2 lists were presented, and recall of TBR list was postcued. Recall proportion decreased with increased TBR list length. Moreover, the authors found extended recency effects when recall was replotted by when words were last rehearsed (Experiments 2 and 3) and an effect of intervening list length when rehearsal was reduced (Experiment 3).

Humans↗

PubMed2004

Item and order memory for novel visual patterns assessed by two-choice recognition.

Five experiments examined item and order memory for short lists of novel visual patterns. Memory was tested either by an item recognition test, choosing between a target and a similar foil (Experiments 1, 3a, and 4), or by a relative recency decision between two patterns that occupied adjacent list positions (Experiments 2, 3b, and 5). For both item recognition and relative recency tasks, accuracy was in most cases constant across serial positions, except for a recency advantage that was usually restricted to the most recent item or recency decision. Only a small and marginally significant effect of list length was observed for item recognition. Relative recency was more sensitive to list length and fell to near-chance levels with lists of eight items. We conclude that for these materials, prerecency item recognition depends on stable, context-free descriptions of items. Relative recency judgements are sensitive to list properties, but fail to show evidence of primacy or extended recency that are observed when other techniques are used to study serial order memory. We discuss the results in relation to four current models of serial order memory that embody different assumptions in the way that serial order is represented.

Adolescent↗

PubMed2003

Using overt rehearsals to explain word frequency effects in free recall.

Three experiments examined the word frequency effect in free recall using the overt rehearsal methodology. Experiment 1 showed that lists of exclusively high-frequency (HF) words were better recalled, were rehearsed more, and were rehearsed to more recent serial positions than low-frequency (LF) words. A small HF advantage remained even when these 2 variables were equated. Experiment 2 showed that all these effects were much reduced with mixed lists containing both HF and LF words. Experiment 3 compared pure and mixed lists in a within-subject design and confirmed the findings of Experiments 1 and 2. It is argued that number of rehearsals, recency of rehearsals, and strength of interitem associations cause the word frequency effect in free recall.

Adolescent↗

PubMed2002

A recency-based account of the list length effect in free recall.

Free recall was examined using the overt rehearsal methodology with lists of 10, 20, and 30 words. The standard list length effects were obtained: As list length increased, there was an increase in the number and a decrease in the proportion of words that were recalled. There were significant primacy and recency effects with all list lengths. However, when the data were replotted in terms of when the words were last rehearsed, recall was characterized by extended recency effects, and the data from the different list lengths were superimposed upon one another. These findings support a recency-based account of episodic memory. The list length effect reflects the facts that unrehearsed words are less recent with longer lists, and that with longer lists, a reduced proportion of primacy and middle items may be rehearsed to later positions.

Humans↗

PubMedDate not supplied

Serial position curves in short-term memory: functional equivalence across modalities.

Four experiments investigated item and order memory for sequences of seen unfamiliar faces and heard nonwords. Experiments 1 and 3 found bowed serial position curves using the serial reconstruction test of order with faces and nonwords, respectively. Experiments 2 and 4 found limited recency, no primacy, and above chance performance on all items using a two-alternative forced choice (2AFC) test of item recognition, again with faces and nonwords. These results suggest that the different serial position curves typically found using traditional paradigms for exploring visual and verbal short-term memory are due to differences in the methods used rather than modality-specific mechanisms.

Acoustic Stimulation↗