New evidence on the nature of the encoding of action events

Differences in recall patterns between subject-performed tasks (SPTs) and verbal materials have been interpreted in terms of SPTs being nonstrategic or automatically encoded. In a series of three experiments, we tested this notion by comparing free recall of SPTs and sentences in conditions of'(1) nondivided versus divided attention for organizable items, (2) organizable versus nonorganizable items, and (3) nondivided versus divided attention for nonorganizable items. It was found that recall of both SPTs and sentences decreased in conditions of divided attention. A decrease in recall was also observed for both types of material when nonorganizable as compared to organizable materials were used. In addition, the degree of clustering was higher for SPTs than for sentences. These data suggest that there is a strategic component involved in the encoding of SPTs. We propose that the action elements of SPTs (e.g., motor features, shape, texture) are automatically encoded, whereas the verbal component is strategically encoded. It is emphasized that organization is an encoding strategy critical to SPT recall.     

Metamemory for words and enacted instructions: Predicting which items will be recalled

Subjects can predict, during word list acquisition, which items they will subsequently recall. When the list items are subject-performed tasks (SPTs), recall prediction is totally inaccurate. Delaying the rating of recall probability (actually, trace strength rating) until list acquisition was complete did not affect the accuracy of the ratings. Word recall was predictable; SPT recall was not. When encoding was systematically manipulated, the effects of the manipulations on recall were accompanied by parallel effects on the strength ratings for SPTs, as well as for words. Several explanations for the data are discussed, the most probable being that of a mismatch between those characteristics of the SPTs that underlie strength ratings and those that determine recall.     

Levels-of-processing effects in subject-performed tasks

In memory for subject-performed tasks (SPTs), subjects encode a list of simple action phrases (e.g., thumb through a book, knock at the door) by performing these actions during learning. In three experiments, we investigated the size of the levels-of-processing effects in SPTs as compared with those in standard verbal learning tasks (VTs). Subjects under SPT and VT conditions learned lists of action phrases in a surface or a conceptual orienting task. Under both encoding conditions, the subjects recalled fewer items with surface orienting tasks than with conceptual orienting tasks, but the levels-of-processing effects were strongly reduced in the SPT condition. In the SPT condition, items that were encoded in a surface orienting task were still substantially recalled. The items were recalled almost as well as the conceptually encoded items in the VT condition. The distinct reduction of the levels-of-processing effect is caused by the fact that, in SPT encoding even with a verbal surface orienting task, subjects process conceptual information in order to perform the denoted action. We attribute the small conceptual advantage, which remains with SPT despite the conceptual processing for performing, to the fact that items are not as well integrated into memory as they are when conceptual processing is focused on the action component, rather than on the semantic contexts. This lower integration reduces the accessibility of items in the verbal surface task, even with SPT encoding.     

Decomposing the encoding of action events: A dual conception

Two experiments are reported in which we tested the hypothesis that encoding of verbal features of subject-performed tasks or SPTs (e.g., bounce the ball, lift the spoon) is attention-demanding and effortful, whereas physical features of this memory task (e.g., color, weight) are acquired with little effort, and without deliberate encoding strategies. In Experiment 1, subjects were asked to perform a series of SPTs and were examined on recall of verbal instructions and colors of objects involved under conditions of focused or divided attention. In Experiment 2, performance of a series of SPTs was followed by recall of verbal instructions and recall of weights of objects involved. Results of both experiments indicated that recall of the verbal task component was negatively affected by requirements of dual-task performance, whereas recall of both physical task features was equally good in both encoding conditions. The obtained pattern of outcome is interpreted as supportive of the dual conception hypothesis of the nature of the encoding of action events.     

Bizarreness effects in verbal tasks and subject-performed tasks

Abstract

Recognition and cued recall of ordinary action phrases (e.g. “open the book”) and bizarre ones (e.g. “plant the hammer”) were compared under two encoding conditions: in verbal tasks (VTs), subjects learned the phrases by simply listening to them; in subject-performed tasks (SPTs), subjects learned the phrases by performing the denoted actions (without real objects). Memory performance was better after SPTs than after VTs in recognition and cued recall. In addition to this already established finding, it was observed that recognition was better for bizarre phrases than for ordinary ones after VTs and that bizarreness was unrelated to recognition after SPTs. Cued recall, on the other hand, depended on bizarreness after VTs as well as after SPTs and, in contrast to the recognition findings, ordinary phrases were recalled better than bizarre phrases. This pattern of findings was explained by the assumptions that lexical and conceptual information is encoded after VTs and motor information is additionally encoded after SPTs, and that different kinds of information are used in recognition and cued recall, and after VTs and SPTs.     

The effects of interference tasks on recency in the free recall of action events

Summary Lists of verbal instructions were read aloud and each was enacted either by the subject (SPTs) or by the experimenter (EPTs). In Experiment 1 free recall was made of lists of SPTs and EPTs either immediately after presentation, after an empty 20-s delay interval, or after a 20-s delay interval filled with backward counting. The recall of recency items was unaffected by the empty delay interval, but was somewhat reduced by the counting task. In Experiment 2 free recall was made of lists of SPTs and EPTs either immediately after presentation or after a delay that was filled with a single SPT or a single EPT, 20 s in length. The recency effect evident in the immediate-recall condition was virtually wiped out in the delay conditions, irrespective of whether the delay task matched those in the free-recall list or not. These results are discussed in terms of the mnemonic similarity of the two types of action event.     

Item and order information in subject-performed tasks and experimenter-performed tasks

This study investigated the enactment effect from the perspective of the item-order hypothesis (e.g., M. Serra & J. S. Nairne, 1993). The authors assumed that in subject-performed tasks (SPTs), item encoding is improved but order encoding is disrupted compared with experimenter-performed tasks (EPTs), that order encoding of EPTs is only better in pure lists, and that the item--order hypothesis is confined to short lists. Item information was tested in recognition memory tests, order information in order reconstruction tasks, and both item and order information in free-recall tests. The results of 5 experiments using short (8 items) and long lists (24 items) in a design with list type (pure, mixed) and encoding condition (EPT, SPT) as factors supported the hypotheses.     

Age differences in memory for prospective compared with retrospective subject-performed tasks

In two experiments, younger and older adults studied three lists of verbal phrases, each of the latter describing a simple action. One list was studied and recalled verbally; one was recalled verbally, but the actions were performed at study [retrospective SPTs (subject-performed tasks)]; and one was studied verbally and the actions were performed at test (prospective SPTs). With long lists, but not with short ones, retrospective-SPT recall exceeded verbal recall and older adults recalled fewer SPTs than did younger adults. Prospective-SPT recall did not exceed verbal recall at either list length, and in each of these prospective-SPT tests, older adults recalled fewer action phrases than did younger adults. Thus, it appears that when retrospective and prospective tasks are equated there are marked age differences that are generally consistent with the view that memory impairment in the elderly is more likely to occur in tasks that make higher attentional processing demands.     

The item-order hypothesis reconsidered: The role of order information in free recall

According to the item-order approach of free recall, in pure short lists the free recall of unrelated items is organized according to their order of presentation in the study list. The approach was applied in the present study to experimenter-performed tasks (EPTs) and subject-performed tasks (SPTs). It claims that EPTs provide better serial order information than SPTs. Consequently, free recall of EPTs should be more organized along the presentation order of the items than the free recall of SPTs. In three experiments, some specific aspects of this approach were studied. Firstly, it was demonstrated that serial retrieval is not strongly used spontaneously and that its use is overestimated in the literature because it is usually evoked by an order reconstruction test which follows free recall testing. Secondly, a serial retrieval strategy in free recall can be encouraged by explicit instructions. Finally, the present experiments showed that a serial output strategy alone does not allow one to predict performance in free recall. The implications of these findings for the item-order approach will be discussed.     

On the generality of some memory laws

Several memory laws have been established for the free recall of word lists. The generality of some of these laws were tested, using tasks which the subjects performed (SPTs) as to-be-recalled list items. SPT recall obeyed one law of word recall in showing a strong positive recency effect in immediate free recall, which appeared to be due to these events being in a temporary state of high accessibility. Differences between word and SPT recall were: 1) The reliable primacy effect associated with word recall did not appear in SPT recall; 2) Subjects reported using active memorisation strategies for word lists, but not for SPT lists; 3) Unlike word recall, diverting the subject's attention to so-called deep or shallow features of the SPTs during presentation did not affect the level of their recall. These results considered together with Cohen & Stewart's (1981) finding that SPT recall was not age-sensitive were taken to indicate that SPTs should be regarded as a different class of memory event than words, and that memory models dealing with SPT recall should de-emphasize the importance of encoding, stressing instead retention, and retrieval operations.     

Organisation and Recall in Verbal Tasks and in Subject-performed Tasks

In memory for subject-performed tasks (SPTs), subjects encode a list of simple action phrases (e.g. "lift the pen", "open the book") by performing these actions during learning. Performing tasks has proved to be a much more efficient type of encoding than verbal tasks (VTs), in which subjects only listen to the action phrases in order to memorise them. It is assumed that good item-specific encoding after SPTs plays an important role in the SPT effect. The role of relational encoding for the SPT effect is less clear, as is the question of whether SPT encoding is automatic or controlled. Two experiments were conducted to address these issues. Subjects learned lists which were categorically structured in VTs and SPTs, under focal attention or divided attention. The results indicated that relational encoding does not differ between VTs and SPTs, and that free recall is impaired in both cases by divided attention, more so in VTs than in SPTs. It is concluded that the SPT effect is primarily based on item-specific information rather than on relational information, and that VTs are more dependent than SPTs on active encoding.     

The ironic effect of guessing: increased false memory for mediated lists in younger and older adults

Younger and older adults studied lists of words directly (e.g., creek, water) or indirectly (e.g., beaver, faucet) related to a nonpresented critical lure (CL; e.g., river). Indirect (i.e., mediated) lists presented items that were only related to CLs through nonpresented mediators (i.e., directly related items). Following study, participants completed a condition-specific task, math, a recall test with or without a warning about the CL, or tried to guess the CL. On a final recognition test, warnings (vs. math and recall without warning) decreased false recognition for direct lists, and guessing increased mediated false recognition (an ironic effect of guessing) in both age groups. The observed age-invariance of the ironic effect of guessing suggests that processes involved in mediated false memory are preserved in aging and confirms the effect is largely due to activation in semantic networks during encoding and to the strengthening of these networks during the interpolated tasks.     

Free recall and complexity of pictorial stimuli

In order to explore variables underlying primacy and recency effects in free recall of pictorial material, norms were developed using 120 subjects who rated the vividness and complexity of slides. Two experiments were then run in which two levels of each of these variables (extreme high and low ratings) were factorially combined. In the first experiment 24 subjects were shown three mixed lists, two short and one long (consisting of materials of all four combinations of vividness and complexity), and in the second experiment 12 subjects were shown four pure lists (consisting of materials of a single type). Analysis of variance showed list length in the mixed list experiment and complexity in both experiments to be strong determinants of recall. Greatest recall was for items of low complexity in short lists. Weak, but statistically significant, serial position effects were evident, particularly for less complex items. The effects of primacy and recency seem to decrease with increasing complexity of visual materials, perhaps because of the greater difficulty in rehearsing more complex pictures either verbally or iconically.     

The Effect of Word Length on Immediate Serial Recall Depends on Phonological Complexity, Not Articulatory Duration

Immediate recall for sequences of short words is better than for sequences of long words. This word-length effect has been thought to depend on the spoken duration of the words (Baddeley, Thomson, & Buchanan, 1975) or their phonological complexity (Caplan, Rochon, & Waters, 1992). In Finnish both vowel and consonant quantity distinguish between words. Long phonemes behave like phoneme repetitions. In Experiment 1, subjects were presented with auditory lists of three kinds of pseudowords based on Finnish phonotactics: short CVCV-structures (e.g. / tepa/ ), long two-syllable items with long phonemes (e.g. / te: p: a / ), and long three-syllable items with CVCVCV structures (e.g. / tepalo / ). Although both kinds of long stimuli (of identical spoken length) took longer to read, only three-syllable items were more difficult to remember than the short stimuli. Experiment 2 contrasted the effect of number of syllables with number of different phonemes. The long two-syllable items were replaced by two-syllable items of equal spoken duration but containing six different phonemes (e.g. / tiempa / ). These two-syllable items were as difficult to recall as were the three-syllable items. Experiment 3 controlled for the possibility that long stimuli might be rehearsed in a shorter form. It is concluded that aspects of phonological complexity are critical for word-length effects. Implications of this finding for working memory theory are discussed, and future work based on multi-layered phonological representations is proposed.     

Categorical-relational and order-relational information in memory for subject-performed and experimenter-performed actions

Memory for self-performed tasks (SPTs) is better than memory for experimenter-performed tasks (EPTs). In short unrelated lists of actions this effect occurs if the encoding condition is manipulated within subjects. In a between-subjects design, the enactment effect disappears (J. Engelkamp & D. Dehn, 2000; J. Engelkamp & H. D. Zimmer, 1997). These findings were explained by the item-order hypothesis, which claims that encoding order information depends on the type of encoding and design. The authors demonstrate that this differential encoding of order information in EPTs and SPTs is not effective in free recall if categorized lists are used. The use of categorized lists makes the interaction of type of encoding and design in free recall of short lists disappear, and the enactment effect reappears independent of the type of design.     

Attentional demands and recall of verbal and color information in action events

Two experiments addressed the influence of secondary task performance at encoding on recall of different features of subject-performed tasks (SPTs) involving objects (e.g., turn the wallet). In Experiment 1, memory for verbs and colors of objects was assessed, with object names serving as cues. In Experiment 2, object and color memory were assessed, with verbs serving as cues. Results from both experiments indicated a greater deterioration of memory performance under divided attention for verbal features than for colors. In addition, intention to remember did not affect performance for any feature in either experiment. The overall pattern of outcome is discussed relative to the view that encoding of verbal features of SPTs is more attention-demanding than encoding of physical task features, such as color.     

The effects of mediated word lists on false recall and recognition

False memory effects were explored using unrelated list items (e.g., slope, reindeer, corn) that were related to mediators (e.g., ski, sleigh, flake) that all converged upon a single nonpresented critical item (CI; e.g., snow). In Experiment 1, participants completed either an initial recall test or arithmetic problems after study, followed by a final recognition test. Participants did not falsely recall CIs on the initial test; however, false alarms to CIs did occur in recognition, but only following an initial recall test. In Experiment 2, participants were instructed to guess the CI, followed by a recognition test. The results replicated Experiment 1, with an increase in CI false alarms. Experiment 3 controlled for item effects by replacing unrelated recognition items from Experiment 1 with both CIs and list items from nonpresented lists. Once again, CI false alarms were found when controlling for lexical characteristics, demonstrating that mediated false memory is not due simply to item differences.     

Social contagion of memory

We report a new paradigm for studying false memories implanted by social influence, a process we call the social contagion of memory. A subject and confederate together saw six common household scenes (e.g., a kitchen) containing many objects, for either 15 or 60 sec. During a collaborative recall test, the 2 subjects each recalled six items from the scenes, but the confederate occasionally made mistakes by reporting items not from the scene. Some intrusions were highly consistent with the scene schema (e.g., a toaster) while others were less so (e.g., oven mitts). After a brief delay, the individual subject tried to recall as many items as possible from the six scenes. Recall of the erroneous items suggested by the confederate was greater than in a control condition (with no suggestion). Further, this social contagion effect was greater when the scenes were presented for less time (15 sec) and when the intruded item was more schema consistent (e.g., the toaster). As with other forms of social influence, false memories are contagious; one person’s memory can be infected by another person’s errors.     

Incidental memory for colour word associates processed in colour naming and reading aloud tasks: is a blue ocean more memorable than a yellow one?

ABSTRACT

Congruency effects for colour word associates (e.g., ocean) have been reported in Stroop colour naming tasks. However, incidental memory for such words after word reading and colour naming tasks has not been examined. In the current study, participants incidentally recalled colour word associates (e.g., ocean) and neutral words (e.g., lawyer) immediately after naming their font colour (Experiment 1a) or reading them aloud (Experiment 1b). In both tasks, recall was better for congruent colour word associates (e.g., ocean appearing in blue) than incongruent colour word associates (e.g., ocean appearing in green) or neutral items (lawyer appearing in blue).

This outcome is consistent with the idea that co-activation of a semantic colour code and a lexical representation strengthens the episodic memory representation and makes it more accessible.