On the independence of judged frequencies for items presented in successive lists*

In an experiment examining retroactive interference effects in a frequency-judging task, all Ss were presented with a list of words occurring varying numbers of times according to either a massed- or distributed-practive (MP or DP) schedule. They were then asked to judge how often each word had occurred. Following this, Ss were given one of four types of second tasks a second list with different items followed by a frequency-judging task for that list (Condition New): a second list with items repeated from the first list but with different frequencies for each item, while either maintaining items as either MP or DP items (Condition Same) or switching MP items to DP, and vice versa (Condition Reverse): followed by a frequency-judging task for the second-list frequencies only: or a puzzle task for the amount of time required for second-list presentation and judgment in the other conditions (Condition None). Finally, all Ss were asked to recall List 1 frequencies, List 2 frequencies were less discriminable in Conditions Same and Reverse than in Condition New. Recall of List 1 frequencies, however, was not different for these three groups, but was poorer than in List 2 frequency judgments were not independent of List 1 frequencies.     

Repetition blindness: levels of processing

Repetition blindness (RB) is the failure to detect or recall repetitions of words in rapid serial visual presentation. Experiment 1 showed that synonym pairs are not susceptible to RB. In Experiments 2 and 3, RB was still found when one occurrence of the word was part of a compound noun phrase. In Experiment 4, homonyms produced RB if they were spelled identically (even if pronounced differently) but not if spelled differently and pronounced the same. Similarly spelled but otherwise unrelated word pairs appeared to generate RB (Experiment 5), but Experiment 6 produced an alternative account. Experiments 7 and 8 demonstrated that repeated letters are susceptible to RB only when displayed individually, not as part of two otherwise different words. It is concluded that RB can occur at either an orthographic (possibly morphemic) level or a case-independent letter level, depending on which unit (words or single letters) is the focus of processing.     

Bartlett revisited: Direct comparison of repeated reproduction and serial reproduction techniques

Bartlett developed the procedures of repeated reproduction (the same person repeatedly recalling information) and serial reproduction (people transmitting information from one person to another). Our experiment directly compared recall accuracy across these two techniques, which has not previously been reported, using DRM word lists. Recall of the initial study list words remained constant across repeated reproductions but declined markedly across serial reproductions. In contrast, recall of associated words that were not originally studied (i.e. critical words) was steady across both conditions. Because more of the original list words were forgotten across each link of the serial reproduction chain, the proportion of critical items recalled (relative to list words) increased significantly as the list passed between people. Using output bound scoring, serial reproduction resulted in lower accuracy than repeated reproduction by the final recall trial. Our results are broadly consistent with Bartlett's (1932) informal observations: Serial reproduction produces greater forgetting of the original material than does repeated reproduction and also leads to greater distortion relative to the proportion of correct material recalled.     

Sex differences in elaborative strategies: a developmental analysis.

The present study examined sex differences in the use of elaboration in paired associate learning in adolescence and young adulthood. In Experiment 1, 48 eighth grade and 48 tenth grade students were asked to recall 24 word pairs, half of which were high frequency pairs, and half low frequency pairs. After recall, students reported the type of strategy used for each word pair (reading the pairs carefully, rehearsing the words, using imagery or constructing a verbal connection). Females used elaborative strategies more often, were more likely to recall elaborated pairs, and recalled more word pairs than males at both ages. These effects were observed in both high and low frequency word pairs. There was also a main effect of frequency, with elaboration more common with high frequency word pairs. In Experiment 2, college students performed the same paired-associates learning task, but with the added instruction to describe their elaborations in a sentence. At this age, there was a sex by materials interaction, with sex differences in strategy use only present with low frequency word pairs. These findings indicate that sex differences diminish under more favorable task conditions that encourage strategy use (high frequency word pairs) as males and females become more proficient strategy users, but remain under less favorable circumstances. An examination of the types of elaborations generated by college students indicated although males and females produced similar types of elaborations to the word pairs, sex differences in the recallability of low frequency words appeared with less interactive and more idiosyncratic elaborations.     

A comparison of the effects of formal similarity among trigrams and among word triads

The central question of this report concerned the role of formal similarity in free recall of lists of trigrams and lists of three-letter word triads. Similarity was manipulated among trigrams by duplicating letters and among triads by duplicating words. An initial study showed that lists of 16 letters were learned more rapidly than a list of 16 three-letter words. Therefore, in the major experiment, the Ss were given all appropriate elements on test trials so that only associative learning was required. Increases in formal similarity caused decreases in rate of learning for both types of lists, and the mechanisms of the interference seemed to be the same for both types of lists, However, the learning of the trigram lists was more rapid than the learning of the triad lists, the difference being maximal with low similarity.     

Short-term memory for intonation.

Ss were presented with lists of 16 words, each word spoken in one of four intonations. The final word was a repetition of one of the first 15 words, 40 Ss having to judge whether it was spoken in the same intonation as its earlier occurrence. A control group of 40 Ss did a similar task, ignoring intonation. Retention of intonation was significantly poorer, indicating that intonation is an additional load not normally retained. This argues against acoustic or articulatory encoding in short-term memory and in favor of an abstract-verbal encoding mode. Results are also interpreted as supporting the position that verbal and motor short-term membory obey similar laws.     

Two-channel visual memory

Ss attempted immediate recall of word and color attributes of series of three “Stroop” words (Experiments I and 2) or three colored number words (Experiments 3 and 4), presented either at 2 words/sec or I word/2 sec. They were instructed to give either channel-by-channel recall, grouping words and colors together, or temporal recall, in which the two attributes of each item were to be reported together. In Experiments I and 3, in which words were to be reported before colors, channel-by-channel recall was rather better than temporal recall, especially at the fast rate. In Experiments 2 and 4, the colors were to be reported before the words, and channel-by-channel recall tended to be worse than temporal recall. In all four experiments serial position data suggested that the channel-by-channel strategy was to attend to one attribute (either words or colors) during presentation and hold the other in preattentive storage. By contrast, when instructed to give temporal report, Ss apparently alternated attention between attributes during presentation.     

Does collaborative remembering reduce false memories?

Collaborative remembering refers to recall by groups rather than by an individual. Three experiments investigated whether, relative to individual remembering, collaborative remembering decreased correct recall and false recall using the Deese‐Roediger‐McDermott paradigm. Participants were first asked to study and recall five lists of 15 words that were each semantically associated with a critical non‐presented word. Half the participants recalled the words by themselves, while the remaining half were assigned to pairs and collaboratively recalled the words. In Experiment 1, pairs produced the same number of false or correct words as individuals who were tested alone. In Experiment 2, the interpersonal closeness of the groups was also manipulated: friends and pairs who were not friends were assigned to the collaborative groups. Both friends and non‐friends produced fewer false or correct words than individuals. Experiment 3, in which the performance of the individuals and non‐friend pairs were compared using a recall test of the same 75 words as the previous experiments, replicated the results of Experiment 2. These results are discussed in terms of the retrieval‐strategy disruption.     

Spacing repetitions over 1 week

Does varying the spacing of repetitions over intervals as long as 1 week aftect recall? The answer from three experiments is yes. Subjects incidentally processed words repeated within a single list and words repeated in separate lists at list spacings of up to 1 week. Memory was tested by free recall shortly after the second presentations or after retention intervals of up to 1 week. Recall of the words repeated across separate lists conformed to a proportionality rule. When the retention interval is short relative to the spacing intervals, performance is inversely related to spacing. When the retention interval is a large proportion of the spacing intervals, performance is directly related to spacing. Does varying the spacing of repetitions within a single list affect recall after a retention interval of 2 weeks? The answer depends on the processing used while studying the words. Processing that generated interitem associations resulted in a within-list spacing effect even after a 2-week retention interval. Without the interitem associations, the effect was absent after a 1-day retention interval. Most of these findings were explained by examining the changing relationship between the retrieval context and the context stored during study.     

The Effect of Morphological Complexity on Verbal Working Memory: Results from Arabic Speaking Children

To examine the role of morphology in verbal working memory. Forty nine children, all native speakers of Arabic from the same region and of the same dialect, performed a Listening Word Span Task, whereby they had to recall Arabic uninflected words (i.e., base words), inflected words with regular (possessive) morphology, or inflected words with irregular (broken plural) morphology. Each of these words was at the end of a sentence (henceforth, target word). The participant’s task was to listen to a series of sentences and then recall the target words. Recall of inflected words was significantly poorer than uninflected words, and recall of words with regular morphology was significantly poorer than recall of words with irregular morphology. These findings, albeit preliminary, suggest a role of morphology in verbal working memory. They also suggest that, at least in Arabic, regular morphological forms are decomposed into their component elements and hence impose an extra load on the central executive and episodic buffer components of working memory. Furthermore, in concert with findings from other studies, they suggest that the effect of morphology on working memory is probably language-specific. The clinical implications of the present findings are addressed.     

Impaired priming of new associations in amnesia

We assessed priming of new associations in amnesic patients and healthy control subjects in a paradigm developed by Graf and Schacter (1985). Subjects were presented unrelated word pairs embedded in sentences (e.g., A BELL was hanging over the baby's CRADLE) and were asked to rate how well the sentences related the two words. Subjects were then given a word completion test. They were shown three-letter word stems and were asked to complete the stem with the first word that came to mind. In the same context condition, each word stem was presented together with the word that had appeared in the same sentence during study (e.g., BELL-CRA--). In the different context condition, each stem was presented together with a new word that had never been presented (e.g., APPLE-CRA--). Control subjects completed more words in the same context condition than in the different context condition. In contrast, amnesic patients did not complete any more words in the same context condition than in the different context condition. Indeed, across two experiments none of the amnesic patients exhibited consistent priming of new associations. Thus, although amnesic patients do exhibit entirely normal priming of preexisting memory representations, they do not appear to exhibit priming of new associations in this paradigm.     

Repetition blindness and bilingual memory: Token individuation for translation equivalents

The repetition blindness effect (RB) occurs when individuals are unable to recall a repeated word relative to a nonrepeated word in a sentence or string of words presented in a rapid serial visual presentation task. This effect was explored across languages (English and Spanish) in an attempt to provide evidence for RB at a conceptual level using noncognate translation equivalents (e.g.,nephew-sobrino). In the first experiment, RB was found when a word was repeated in an English sentence but not when the two repetitions were in different languages. In the second experiment, RB was found for identical repetitions in Spanish and in English using word lists. However, the crosslanguage condition produced significant facilitation in recall, suggesting that although conceptual processing had taken place, semantic overlap was not sufficient to produce RB. The results confirm Kanwisher’s (1987) token individuation hypothesis in the case of translation equivalents.     

Association and categorisation effects on free recall

Lists of 18 words which varied in mean associative strength, the category membership of the associations and in word frequency were presented to subjects 3 times with recall required after each presentation. Recall efficiency increased with association level and with similarly categorised associates. In lists of High mean associative strength which consisted of similarly categorised words, the recall of high frequency word lists was facilitated but at low levels of associative strength, with similarly categorised words, recall was facilitated at both levels of word frequency used. Clustering and errors which were associatively related to the items being learned were greater in lists which contained sets of similarly categorised associates.     

Paired associate learning: Data on pair difficulty and variables that influence difficulty

Two hundred pairs of five-letter words were produced randomly from all five-letter words in Thorndike and Lorge (1944). The difficulty of each pair was established for paired associate learning by having 50 subjects learn lists of 20 pairs. The difficulty of a pair was found to be highly reliable and was not influenced by the particular list in which it was learned. Frequency of response terms was positively related to learning, but the frequency of the stimulus terms was not. Two-syllable five-letter words were learned more rapidly than one-syllable five-letter words. Two 20-pair lists were constructed, one consisting of homogeneous pairs of average difficulty and the other of 10 very easy pairs and 10 very difficult pairs. As anticipated, performance on the latter list was initially better than that on the former, with the performance on the two lists converging over trials. The difficulty of the pairs as determined by paired associate learning was unrelated to misses on a recognition test, but the false alarms decreased as difficulty decreased.     

Detection of letter repetition in words and nonwords: the effect of opposite-case distractors.

This study tested whether it is the repetition of the letter's name and not its shape that is detected faster in a word than in a nonword (Krueger, 1989). Ss judged whether the same letter shape or the same letter name was repeated in a 6-letter word or nonword. When the shape was repeated, the word advantage was nearly as large (about 50 ms) when Ss looked for a physical match as when they looked for a name match. When the 2 repeated letters differed in case, however, the word advantage was very large (208 ms) when Ss looked for a name match and were thus rewarded for nonvisual coding, but the advantage vanished ((-35)-ms word deficit) when Ss looked for a physical match and were thus penalized for nonvisual coding. This indicates that letter names are much more accessible in words than in nonwords, and that words are primarily encoded nonvisually.     

The effect of presemantic acoustic adaptation on semantic “satiation”

A decrement in the strength of the meaning of a word after rapid repetition of that word has been called “semantic satiation.” This study asked whether this “satiation” might be produced by presemantic acoustic adaptation. Category words were utilized to prime the meaning of target words. The adaptation or “satiation” procedure, 30 rapid repetitions of the primes, was compared with a control condition of 3 repetitions. Participants listened to a series of prime words, each repeated by either the same speaker or many speakers, and then made semantic decisions on target words. When all the repetitions of a prime word are produced by the same speaker, presemantic and semantic repetitions are confounded. When the repetitions are produced by different speakers, presemantic acoustic repetition is abolished. A semantic decrement was detected with single-speaker, but not with multiple-speaker, repetitions of prime words. This study concluded that the semantic “satiation” observed here was a decrement in the activation level of semantic representations induced by presemantic acoustic adaptation.     

Detrimental influence of contextual change on spacing effects in free recall

Two experiments were conducted to determine the mechanism underlying the spacing effect in free-recall tasks. Participants were required to study a list containing once-presented words as well as massed and spaced repetitions. In both experiments, presentation background at repetition was manipulated. The results of Experiment 1 demonstrated that free recall was higher for massed items repeated in a different context than for massed items repeated in the same context, whereas free recall for spaced items was higher when repeated in the same context. Furthermore, a spacing effect was shown for words repeated in the same context, whereas an attenuated spacing effect was revealed for words repeated in a different context. These findings were replicated in Experiment 2 under a different presentation background manipulation. Both experiments seem to be most consistent with a model that combines the contextual variability and the study-phase retrieval mechanism to account for the spacing effect in free-recall tasks.     

Imagery and compatibility of pairing in the free recall of adjective-noun pairs

Can the image-evoking value (I) of single words be used to predict the recall of grammatical units in which they occur? Thirty-two subjects free-recalled a list of 24 adjective-noun pairs varying in the I of the adjective and the noun, and the compatibility (C) of the pairing (i.e. whether or not the pair was immediately meaningful). Analysis showed all three variables to affect recall. High I adjectives facilitated recall irrespective of the I of the noun or the C of the pairing. Noun I and C facilitated recall only when both noun I was high and the pairing was compatible. An examination of intertrial repetitions failed to find evidence of organization in recall. Where only one word from a pair was recalled it tended to come from an incompatible pair, supporting the hypothesis that the recall of one word from an incompatible pair is less likely to cue recall of the other word than is the recall of one word from a compatible pair.     

Efficiency of Learning as a Function of Practice Schedule and Initial Ability

2 groups of 50 Ss practiced a pursuit rotor skill under different schedules of practice. A massed practice (MP) group (40 sec. work, 20 sec. rest) performed just as well as a distributed practice (DP) group (20 sec. work, 20 sec. rest) on the first day of practice. However, after 24 hr. of interpolated rest MP Ss demonstrated significantly greater amounts of learning. A further analysis of the 15 high initial ability and 15 low initial ability Ss from each of the two main groups resulted in no statistical differences among these subgroups in Day 1 performance that could be attributed to the practice schedules; however, a significant Ability Level × Practice Schedule interaction was obtained for Day 2 performance. It was caused by the low ability Ss under MP learning relatively more than the high ability Ss under MP when compared to the two DP groups. Thus learning was seen as being a function not only of schedule of practice but also of initial ability level.