Ian Neath

The nature of remembering: Essays in honor of Robert G. Crowder.

This festschrift in honor of Robert G. Crowder presents thought-provoking new research for scientists in the field of memory and cognition. Authors discuss Crowders far-reaching influence in the field of memory and cognition.

A Temporal Ratio Model of Memory

A model of memory retrieval is described. The model embodies 4 main claims: (a) temporal memory--traces of items are represented in memory partly in terms of their temporal distance from the present; (b) scale-similarity--similar mechanisms govern retrieval from memory over many different timescales; (c) local distinctiveness--performance on a range of memory tasks is determined by interference from near psychological neighbors; and (d) interference-based forgetting--all memory loss is due to interference and not trace decay. The model is applied to data on free recall and serial recall. The account emphasizes qualitative similarity in the retrieval principles involved in memory performance at all timescales, contrary to models that emphasize distinctions between short-term and long-term memory.

Modeling the effects of irrelevant speech on memory.

The feature model (Nairne, 1990) is extended to account for the effects of irrelevant speech and concomitant interactions in immediate serial recall. In the feature model, both articulatory suppression and irrelevant speech are seen as adding noise to the memory representation, the difference being that articulatory suppression diverts more resources than does irrelevant speech. The addition of noise impairs recall because it reduces the probability of successful redintegration. When a competitor is incorrectly recalled, rather than the correct item, this competitor is recalled out of order, producing an increase in order errors. Six simulations are reported that show that the model accounts for (1) the impairment by both irrelevant speech and articulatory suppression, (2) the irrelevance of the phonological and semantic composition of the irrelevant speech, (3) greater disruption when the irrelevant speech tokens vary, (4) the abolition of the phonological similarity effect for visual, but not for auditory, items, (5) the abolition of the word length effect for both visual and auditory items, and (6) the abolition of the irrelevant speech effect under articulatory suppression for both visual and auditory items. The feature model is compared with the two other major views of irrelevant speech, the phonological store hypothesis and the changing state hypothesis.

Word-length effects in immediate memory: Overwriting trace decay theory.

Memory is worse for items that take longer to pronounce, even when the items are equated for frequency, number of syllables, and number of phonemes. Current explanations of the word-length effect rely on a time-based decay process within the articulatory loop structure in working memory. Using an extension of Nairne’s (1990) feature model, we demonstrate that the approximately linear relationship between span and pronunciation rate can be observed in a model that does not use the concept of decay. Moreover, the feature model also correctly predicts the effects of modality, phonological similarity, articulatory suppression, and serial position on memory for items of different lengths. We argue that word-length effects do not offer sufficient justification for including time-based decay components in theories of memory.

Distinctiveness and serial position effects in recognition

Digitized photographs of snowflakes were presented for a recognition test after retention intervals of varying durations. While overall accuracy and discrimination remained constant, as the retention interval increased, primacy increased from chance to reliably better than chance while recency decreased to chance levels. A variation of Murdock’s (1960) distinctiveness model accounted for the changing primacy and recency effects observed in both between- and within-subjects designs. The generality of the model was examined in two different paradigms: lexical access during sentence processing, and free recall in the continual distractor paradigm. In both cases, the model made accurate qualitative predictions for both latency and accuracy measures.

Schedules of presentation and temporal distinctiveness in human memory.

Recency, in remembering a series of events, reflects the simple fact that memory is vivid for what has just happened but deteriorates over time. Theories based on distinctiveness, an alternative to the multistore model, assert that the last few events in a series are well remembered because their times of occurrence are more highly distinctive than those of earlier items. Three experiments examined the role of temporal and ordinal factors in auditorily and visually presented lists that were temporally organized by distractor materials interpolated between memory items. With uniform distractor periods, the results were consistent with Glenbergs (1987) temporal distinctiveness theory. When the procedure was altered so that distractor periods became progressively shorter from the beginning to the end of the list, the results were consistent for only the visual modality; the auditory modality produced a different and unpredicted (by the theory) pattern of results, thus falsifying the claim that the auditory modality derives more benefit from temporal information than the visual modality. We distinguish serial order information from specifically temporal information, arguing that the former may be enhanced by auditory presentation but that the two modalities are more nearly equal with respect to the latter.

SIMPLE: Further Applications of A Local Distinctiveness Model of Memory

Publisher Summary This chapter illustrates the basic properties of SIMPLE by examining its ability to account for data. It provides an overview of the model and then applies it to new data on serial position effects in absolute identification tasks, arguing for a link between discrimination in absolute identification and discrimination of memories in traditional serial recall paradigms. The data support the idea that people represent items based on temporal rather than ordinal position in many paradigms and then offer a unified account of serial position effects. The chapter shows how SIMPLE is beginning to be applied to data used to support the idea of working memory and then returns to the important issue of whether items are best thought of as being encoded using ordinal or temporal position cues. The chapter concludes by addressing some arguments against the idea that unitary memory principle may apply over different time scales.

Distinctiveness and Very Short-term Serial Position Effects

The serial position function reflects better memory for the first and last few items in a list than for the middle items. Four experiments examined the effects of temporal spacing on the serial position function for five-item lists that took between 0.5 seconds and 1.1 seconds to present. As with recall of far longer-lasting lists, recency and other robust serial position effects were observed with both free and serial recall. We demonstrate that temporal schedules of presentation control recall probability in predictable ways, and conclude that very fleeting lists obey similar principles as do longer-lasting lists. We compare both sets of findings with predictions from the dimensional distinctiveness framework.

Modality, concreteness, and set-size effects in a free reconstruction of order task

Would informing subjects which items were presented on the current list remove effects of presentation modality, concreteness, and set size in a long-term free reconstruction of order task? In Experiment 1, a typical modality effect was found: memory for the final item in a list was enhanced when the item was presented auditorily rather than visually. In Experiment 2, order memory was better for concrete than for abstract items. And in Experiment 3, order memory was better when the same six items were presented on every trial than when a unique set of six items was presented. In all conditions in all experiments, the to-be-remembered items were given to the subject at test. These results suggest that contrary to a popular assumption, the reconstruction of order task does not provide a functionally pure measure of order memory

Abolishing the Word-Length Effect.

The authors report 2 experiments that compare the recall of long and short words in pure and mixed lists. In pure lists, long words were much more poorly remembered than short words. In mixed lists, this word-length effect was abolished and both the long and short words were recalled as well as short words in pure lists. These findings contradict current models that seek to explain the word-length effect in terms of item-based effects such as difficulty in assembling items, or in terms of list-based accounts of rehearsal speed. An alternative explanation, drawing on ideas of item complexity and item distinctiveness, is proposed.