Facilitation effect of incidental environmental context on the computer screen for paired-associate learning.

Three experiments, in which a total of 198 undergraduates engaged, investigate whether the incidental environmental context on the computer screen influences paired-associate learning. Experiment 1 compared the learning of foreign- and native-language words between a constant context condition, where the stimulus and response pairs were presented twice on the same 5-s video background context, and a varied context condition, where the pairs were presented twice on different video contexts. Repetition in the same context resulted in better learning than in different contexts, evaluated with a paper-and-pencil test. Experiment 2 investigated learning of paired-associate foreign and native words in the same video contexts, or photograph contexts, or on a neutral grey background. Both the video and the photograph contexts equally facilitated the paired-associate learning compared with the grey background. Experiment 3 investigated whether the incidental environmental context similarly facilitated face-name paired-associate learning. We added a new condition of spot illustrations, and a second testing 1 day later. The repetition of face-name pairs within the same complex incidental environmental context on the computer screen (either video or photograph background) facilitated the paired-associate learning. There was no significant difference in learning performance between video and photograph background contexts, which were significantly better than grey or spot-illustration backgrounds which did not differ from each other. The retention interval did not interact with the effect of the background. The present results show that repetition within the same video or photograph context, covering the entire background of the video screen on which each item pair was superimposed, facilitates paired-associate learning.

Reexamination of mood-mediation hypothesis of background-music-dependent effects in free recall.

The present study reexamined the mood-mediation hypothesis for explaining background-music-dependent effects in free recall. Experiments 1 and 2 respectively examined tempo- and tonality-dependent effects in free recall, which had been used as evidence for the mood-mediation hypothesis. In Experiments 1 and 2, undergraduates (n = 75 per experiment) incidentally learned a list of 20 unrelated words presented one by one at a rate of 5 s per word and then received a 30-s delayed oral free-recall test. Throughout the study and test sessions, a piece of music was played. At the time of test, one third of the participants received the same piece of music with the same tempo or tonality as at study, one third heard a different piece with the same tempo or tonality, and one third heard a different piece with a different tempo or tonality. Note that the condition of the same piece with a different tempo or tonality was excluded. Furthermore, the number of sampled pieces of background music was increased compared with previous studies. The results showed neither tempo- nor tonality-dependent effects, but only a background-music-dependent effect. Experiment 3 (n = 40) compared the effects of background music with a verbal association task and focal music (only listening to musical selections) on the participants' moods. The results showed that both the music tempo and tonality influenced the corresponding mood dimensions (arousal and pleasantness). These results are taken as evidence against the mood-mediation hypothesis. Theoretical implications are discussed.

Odor-context effects in free recall after a short retention interval: a new methodology for controlling adaptation.

The present study investigated context effects of incidental odors in free recall after a short retention interval (5 min). With a short retention interval, the results are not confounded by extraneous odors or encounters with the experimental odor and possible rehearsal during a long retention interval. A short study time condition (4 s per item), predicted not to be affected by adaptation to the odor, and a long study time condition (8 s per item) were used. Additionally, we introduced a new method for recovery from adaptation, where a dissimilar odor was briefly presented at the beginning of the retention interval, and we demonstrated the effectiveness of this technique. An incidental learning paradigm was used to prevent overshadowing from confounding the results. In three experiments, undergraduates (N = 200) incidentally studied words presented one-by-one and received a free recall test. Two pairs of odors and a third odor having different semantic-differential characteristics were selected from 14 familiar odors. One of the odors was presented during encoding, and during the test, the same odor (same-context condition) or the other odor within the pair (different-context condition) was presented. Without using a recovery-from-adaptation method, a significant odor-context effect appeared in the 4-s/item condition, but not in the 8-s/item condition. Using the recovery-from-adaptation method, context effects were found for both the 8- and the 4-s/item conditions. The size of the recovered odor-context effect did not change with study time. There were no serial position effects. Implications of the present findings are discussed.

Effects of study time and meaningfulness on environmental context-dependent recognition.

In two experiments, we examined whether the size of place-context-dependent recognition decreased with study time and with the meaningfulness of the to-be-remembered materials. A group of 80 undergraduates intentionally studied a list of words in a short (1.5 s per item) or a long (4.0 s per item) study-time condition (Exp. 1). Another 40 undergraduates studied lists consisting of words and nonwords in the long-study-time condition (Exp. 2). After a short retention interval, recognition for the targets was tested in the same or in a different context. Context was manipulated by means of the combination of place, subsidiary task, and experimenter. Significant context-dependent recognition discrimination was found for words in the short-study-time condition (Exp. 1), but not in the long-study-time condition (Exps. 1 and 2). Significant effects were found as well for nonwords, even in the long-study-time condition (Exp. 2). These results are explained well by an outshining account: that is, by principles of outshining and encoding specificity.

Context-dependent effects of background colour in free recall with spatially grouped words.

Three experiments investigated context-dependent effects of background colour in free recall with groups of items. Undergraduates (N=113) intentionally studied 24 words presented in blocks of 6 on a computer screen with two different background colours. The two background colours were changed screen-by-screen randomly (random condition) or alternately (alternation condition) during the study period. A 30-second filled retention interval was imposed before an oral free-recall test. A signal for free recall was presented throughout the test on one of the colour background screens presented at study. Recalled words were classified as same- or different-context words according to whether the background colours at study and test were the same or different. The random condition produced significant context-dependent effects, whereas the alternation condition showed no context-dependent effects, regardless of whether the words were presented once or twice. Furthermore, the words presented on the same screen were clustered in recall, whereas the words presented against the same background colour but on different screens were not clustered. The present results imply: (1) background colours can cue spatially massed words; (2) background colours act as temporally local context; and (3) predictability of the next background colour modulates the context-dependent effect.

Effects of simple- and complex-place contexts in the multiple-context paradigm.

In four experiments, a total of 384 undergraduates incidentally learned a list of 24 nouns twice in the same context (same-context repetition) or different contexts (different-context repetition). Free recall was measured in a neutral context. Experiments 1, 2, and 3 used a context repetition (same- or different-context repetition) × inter-study and retention intervals (10 min or 1 day) between-participants design. Context was manipulated by the combination of place, social environment, and encoding task (Experiment 1), place and social environment (Experiment 2), or place alone (Experiment 3). Experiment 4 used a context repetition × type of context (context manipulated by place or by place, social environment, and encoding task) between-participants design, with a 10-min inter-study interval and a one-day retention interval. The present results indicate that the determinant of the superiority of same- or different-context repetition in recall is the type of context. Implications of the results were discussed.

Influences of environmental context on the recency effect in free recall.

A total of 208 undergraduate participants incidentally encoded a list of seven pairs of familiar words in two experiments. A 30-sec calculation task was imposed before and after each pair was encoded. Participants received a free recall test 24 h (Experiment 1) or 10 min (Experiment 2) after the encoding session, under conditions in which the original environmental context was reinstated or not. The environmental context was manipulated in terms of the combination of the physical features of the room, the subsidiary task conducted, the experimenter (Experiment 1), or background music (Experiment 2). A recency effect appeared when the original environmental context was reinstated in both experiments, even though the IPI/RI ratio was too small to produce recency effects according to the ratio rule. The results imply that the environmental context should be taken into account for the recency effect.

Study-time effect on free recall within and out of context.

Three experiments examined whether or not the study-time effect, which was observed when recall took place in the original environmental context, was eliminated or markedly diminished when recall took place in a different environmental context. A total of 456 undergraduates studied a list of words for either a short or long study time before receiving an oral free recall test under conditions where the original environmental context was or was not reinstated. Environmental context was manipulated by the combination of physical features of the room, subsidiary task, and experimenter. Inter-item association was minimised in Experiment 1, and free recall performance was measured independently of inter-item association in Experiments 2 and 3. The results were: (1) a greater study-time effect was found when the original context was reinstated than when it was not reinstated, and (2) the study-time effect disappeared when neither contextual nor inter-item associative cues were available. The results suggest that environmental context is involved in the production of the study-time effect.

[Effects of contextual variation during encoding on decontextualization of episodic memory].

Two experiments examined whether or not contextual variation during encoding of a list enhances decontextualization of episodic memory of the list. A total of 86 undergraduates incidentally encoded a list of 24 nouns twice under the same (same-context repetition condition) or different (different-context repetition condition) contexts with a one-week inter-encoding interval. One week after the second encoding of the list, the undergraduates were asked to free recall the list under the third neutral context. Context was manipulated by the combination of three contextual elements: physical features of environment, types of encoding tasks, and social factors. Experiment 1 revealed superiority of same-to different-context repetition condition, whereas the preceding studies manipulating only environmental features found superiority of different-to same-context repetition condition. Experiment 2, in which participants were explicitly instructed that the list used in the first and the second encoding sessions were identical, replicated the findings of Experiment 1. The present findings suggest that contextual variation between episodes does not enhance decontextualization of episodic memory.

[Environmental context effects of background colors on recognition memory].

Three experiments examined whether or not switching study background-color contexts among target words at testing reduces word-recognition performance. These experiments also examined whether or not presentation rate--one of the determinants of item strength--interacted with background-color context. Undergraduates learned 40 target words presented at a rate of 1.5 or 3.0 seconds per word in one of two background-color contexts in Experiment 1, and in one of ten contexts in Experiments 2 and 3. Recognition of the targets was tested by mixing 40 distractor words with the targets immediately after the learning session in Experiments 1 and 2, and with a 5-minute filled retention interval in Experiment 3. Experiment 1 failed to find background-color context effects on recognition, but Experiments 2 and 3 successfully found the context effects. Presentation rate did not interact with the context effects. The results conflict with the ICE theory. The implications of the present findings are discussed.

Effects of environmental context manipulated by the combination of place and task on free recall.

Three experiments, using a 2 (study context) x 2 (test context) between-subjects design, were conducted to examine the effects of environmental context manipulated by the combination of two contextual elements, place and task, on free recall. Undergraduates individually studied nouns and received a free-recall test, with a 10-minute filled retention interval. The contexts were manipulated by the combination of task and place in Experiment 1, by place alone in Experiment 2, and by task alone in Experiment 3. For the manipulation of place and task, two perceptually distinctive places and two distinctive tasks (a calculation task and a fine-motor task) were used. Tasks were imposed before and after studying target items and before a free-recall test. Significant environmental-context effects were yielded in Experiment 1, but not in the other experiments. The implications of the results are discussed.