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Copyright ? 2006-2013 Scientific Research Publishing Inc. All rights reserved.
2013. Vol.4, No.9, 677-681
Published Online September 2013 in SciRes (http://www.scirp.org/journal/psych) http://dx.doi.org/10.4236/psych.2013.49096
Copyright © 2013 SciRes. 677
Encoding Organizational Source and Associative Source under
Incidental and Intentional Learning Conditions
Department of Psychology, Fudan University, Shanghai, China
Received May 24th, 2013; revised July 15th, 2013; accepted August 6th, 2013
Copyright © 2013 Lei Zhu. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original
work is properly cited.
The present study aimed at providing a plausible answer for the controversy whether organizational
source or associative source could be encoded in a more automatic manner through incidental learning. In
the experiment, subjects were asked to learn organizational and associative sources under incidental or
intentional learning conditions. It turned out that only associative source accuracy increased when sub-
jects were instructed to intentionally learn that source, which implied that associative source might be
encoded in a more effortful way, whereas processing of organizational source might be performed inci-
Keywords: Organizational Source; Associative Source; Incidental Learning; Intentional Learning
People encounter lots of information from various sources
every day. Sometimes, when they retrieve the remembered
information, they are also required to identify the related source
of this information. In the typical source memory tasks, sub-
jects were presented with items from at least two different
sources (e.g., Zhu et al., 2010). The items to be learned include
words, pictures, statements, and so on. And the source refers to
a variety of characteristics which specify the conditions under
which the learning items are presented, such as their color,
shape, size, spatial location, temporal order and the media or
modality of presentation.
In the recent decades, there is increasing evidence which sug-
gested that source memory might be fundamentally different
from memory for the item. That is, compared to memory for-
mation for item, encoding source is a more effortful task which
is performed intentionally and requires considerable attentional
resources (Spencer & Raz, 1995; Troyer & Craik, 2000). For
example, the population with decline of frontal executive sys-
tems and reduced attentional resources, such as older adults and
amnesia patients showed more deficits in remembering the
sources than in remembering the items (Schacter, 1987; Schac-
ter et al., 1991; Ferguson et al., 1992; Hashtroudi et al., 1994;
Chalfonte et al., 1996; Wegesin et al., 2000). In addition, en-
coding source was interfered more severely by the secondary
tasks under divided attention condition than was encoding item
(Troyer et al., 1999; Troyer & Craik, 2000). Similarly, com-
pared with intentional learning conditions, source accuracy
decreased under incidental learning conditions (Chalfonte &
Johnson, 1996; Marsh et al., 2004; Kuo & Van Petten, 2006;
Uncapher & Rugg, 2009).
However, not all the source is encoded in the same way. One
insight comes from the dichotomy between automatic and ef-
fortful processes proposed by Hasher and Zacks (1979). Ac-
cording to Hasher and Zacks (1979), automatic memory proc-
esses which require minimal attentional resources can occur
without intention and do not benefit from practice. Contrarily,
effortful memory processes such as rehearsal or elaborative
mnemonic activities which require considerable attentional
resources are initiated intentionally and show benefits from
practice. Based on that, Hasher and Zacks (1979) further pro-
posed that different from other source, spatial locations, tem-
poral orders tend to be encoded incidentally by automatic
memory processes. Yet, on the contrary, other researchers clas-
sified source into two categories (Geiselman & Bjork, 1980;
Baddeley, 1982; Moscovitch, 1992; Spencer & Raz, 1995;
Staresina & Davachi, 2008). Opposite to Hasher and Zacks
(1979), source, such as spatial locations or temporal orders, is
thought to be extrinsic to the item and not be encoded concur-
rently with the item. Thus, more intentional effort is required to
bind it to the item. This type of source has been named as ex-
trinsic (Geiselman & Bjork, 1980; Baddeley, 1982), organiza-
tional (Moscovitch, 1992), spatiotemporal (Spencer & Raz,
1995), or item-context (Staresina & Davachi, 2008) source. On
the other hand, source, such as color, font, shape, is likely to be
encoded automatically without conscious intention, because it
is directly bound to the item itself and is encoded concurrently
with the item. This type of source is denominated as intrinsic
(Geiselman & Bjork, 1980; Baddeley, 1982), associative (Mos-
covitch, 1992), stimulus bound (Spencer & Raz, 1995), or item-
feature (Staresina & Davachi, 2008) source. Thus, it is still an
open question whether organizational source or associative
source could be encoded in a more automatic manner through
To test this, participants were asked to encode organizational
source (i.e., location) and associative source (i.e., color) under
incidental or intentional learning conditions. They first studied
a list of colored objects presented in the top or bottom of the
computer screen during three tasks (Figure 1). In the item-
oriented task, participants judged whether the items depicted in
pictures were animate. In the color-oriented task, they judged
whether the item-color conjunctions were plausible (red hat) or
not (green orange) in real life. In the location-oriented task,
they judged whether it was plausible in the real life that the
item appeared in the sky when the item was presented in the top
of the screen and judged whether it was plausible in the real life
that the item appeared in the ground when the item was pre-
sented in the bottom of the screen. Thus, organizational source
was intentionally learned in location-oriented task, but was
incidentally learned in the other two tasks, whereas associative
source was intentionally learned in color-oriented task, but was
incidentally learned in the other two tasks. It should be noted
that such manipulation of intentional and incidental learning is
different from the traditional Craik and Lockhart (1972) defini-
tion for item memory. The Craik and Lockhart (1972) distin-
guish intentional and incidental learning by explicit instruction
to learn specific item, whereas the present study distinguish
intentional and incidental learning by the encoding task. After
that, participants took a surprised subsequent memory test
where they first gave old/new decision, and then, for items
called old, they gave source (color and location) judgment. It is
predicted that if the associative source needs to be encoded
intentionally by effortful memory processes, then the source
accuracy of color would benefit from intentional learning. On
the other hand, if organizational source is encoded through
intentional learning, the source accuracy of location would
differ for three tasks.
Fourteen right-handed Chinese volunteers from the univer-
sity community with normal or corrected-to-normal vision (three
Experimental Design. (a) Encoding phase. The task cues were
varied between trials and participants were instructed to conduct
location-oriented task, color-oriented task or item-oriented task
according to the task cue; (b) Subsequent memory test. For the
items judged as “old” in the item memory test, their source mem-
ory for location and color was further assessed.
males, aged from 19 to 29, M = 22.00, SD = 3.11) participated
in this experiment. All the participants were naïve about the
purpose of the experiment and were paid 20 RMB for their
Two hundred and forty gray pictures of common objects
were randomly selected from the revised Snodgrass and Van-
derwart’s object pictorial set (Rossion & Pourtois, 2004) as
materials, 180 of which were randomly selected to serve as
learning items with 60 for each task condition and 60 of which
served as lures during the memory test. The learning items in
each condition were randomly transferred into two different
colors (red [RGB: 255, 0, 0] or blue [RGB: 0, 0, 255]), with 30
items in each color. Then, 30 items in each color for each task
were randomly assigned to two locations, with 15 items in each
location. Complexity, agreement, imagery and familiarity of the
items were counterbalanced across different conditions, differ-
ent colors and different locations. The pictures subtended about
10˚ vertical and horizontal visual angles in the encoding phase
and 12˚ in the test phase at the viewing distance of about 50 cm.
All the stimuli were presented on a white screen with a resolu-
tion of 640 × 480 pixels.
The participants were not informed about the subsequent
memory test before the task. During the encoding phase, 180
learning items were presented sequentially (Figure 1). For each
encoding trial, a 1 s task cue was presented at first, followed by
a 3 s colored item. The task cues were varied between trials and
participants were required to judge whether it was plausible to
encounter the item appearing in the sky (when the item appear
in the top) or ground (when the item appear in the bottom)
when viewing “LOCATION PLAUSIBLE?” (location-oriented
task), but judge whether it was plausible to encounter the item
appearing in the given color in real life when viewing “COLOR
PLAUSIBLE?” (color-oriented task). They were also asked to
judge whether the item depicted in the picture was animate
when viewing “ANIMATE?” (item-oriented task). Reponses
were given via participant’s key press. The order of presenta-
tion sequence was randomized across participants.
About five minutes after the encoding phase, participants
were given a surprised self-paced memory test. 240 gray ob-
jects were presented sequentially in a random order across par-
ticipants. Participants were instructed to indicate whether the
object was old (presented during the encoding phase) or new
(not presented during the encoding phase). If they responded as
“old”, they were then required to indicate the related location
and color of the object. The order of the location and color
judgments were counterbalanced between participants.
The encoding trials with no responses (0.16% ± 0.34% of tri-
als) were excluded from further analyses. As is shown in Table
1, the location-oriented trials and the color-oriented trials pro-
duced similar rates of “YES” responses (judged to be plausible
and animate for all the trials, t(13) = 0.49, p > .05, 1 − β = 0.07),
whereas the proportions of “YES” responses in both tasks were
Copyright © 2013 SciRes.
Behavioral performance during encoding and subsequent memory test.
Task “YES” proportion
(hit rate %)
Location-oriented 56.79 ( 9.57) 1330 (190) 73.33 (14.75)
Color-oriented 54.34 (16.18) 1431 (217) 78.94 (10.34)
Item-oriented 32.29 ( 6.04) 1072 (184) 67.69 (14.48)
Note: Standard errors are given in parentheses. Average “yes” proportions and
recognition hit rates (%) across participants is shown as a proportion of all valid
encoding trials within each task.
higher than that in the item-oriented task (ts > 4.71, ps < .05
with Bonferroni correction for multiple comparison). Besides,
participants responded faster in the item-oriented task than in
the location-oriented task (t(13) = 9.50, p < .05 with Bonferroni
correction for multiple comparison) and responded faster in the
location-oriented task than in the color-oriented task (t(13) =
2.46, p < .05 with Bonferroni correction for multiple compari-
Turning to the subsequent memory performance during test,
the learning items were recognized at a rate of 73.32% ±
11.63% and lures were correctly rejected at a rate of 86.31% ±
7.34%. As shown in Table 1, the mean recognition hit rate in
the color-oriented task was significantly higher than that in the
item-oriented task (t(13) = 3.87, p < .05 with Bonferroni cor-
rection for multiple comparison). The difference of hit rates
between the color-oriented and the location-oriented, the loca-
tion-oriented and the item-oriented conditions did not reach
Last, the source accuracy of location and color in three tasks,
taken as the proportion of correctly recognized trials, are illus-
trated in Figure 2. A 3 task * 2 source ANOVA revealed that
the main effect of source (F(1, 13) = 60.12, p < .01), the main
effect of task (F(2, 26) = 14.54, p < .01) and the interaction
(F(2, 26) = 18.64, p < .01) were significant. This result indi-
cated that the source accuracy of location was higher than that
of color. Further analysis revealed the source accuracy in the
color-oriented task was higher than in the other two tasks (ts >
4.14, ps < .05 with Bonferroni correction for multiple compari-
son), whereas the difference of source accuracy between the the
location-oriented and the item-oriented tasks did not reach sta-
tistical significance (t(13) = 1.44, p > .05, 1 − β = 0.27). Be-
sides, simple effect analysis of the task effect revealed that the
effect did not differ from zero for location judgment (F(2, 26) =
1.67, p > .05, 1 − β = 0.32), but was significantly greater than
zero for color judgment (F(2, 26) = 30.35, p < .01). Further
analysis revealed that the source accuracy of color in the
color-oriented task was higher than that in the other two tasks
(ts > 5.98, ps < .05 with Bonferroni correction for multiple
comparison), whereas the difference of source accuracy of
color between the location-oriented and the item-oriented tasks
did not reach statistical significance (t(13) = 0.41, p > .05, 1 − β
= 0.07). These findings suggested that the associative source
(i.e., color) needs to be encoded intentionally because its source
accuracy benefited from intentional learning, whereas the or-
ganizational source (i.e., location) could be encoded in a more
Average source accuracy of location and color in three tasks.
Eorror bars indicates +/− standard errors.
The present study aimed at providing a plausible answer for
the controversy whether organizational source or associative
source could be encoded in a more automatic manner through
incidental learning. Consistent with Hasher and Zacks (1979),
the results implied that organizational source might be encoded
in a more automatic manner through incidental learning, but
associative source might be encoded in a more effortful way,
since only associative source accuracy increased when subjects
were instructed to intentionally learn that source. However, as
Hasher and Zacks’s (1979) viewpoint, automatic and effortful
memory processes can be distinguished from three aspects:
whether it requires considerable attentional resources; whether
it can occur without intention; and whether it benefits from
practice. The present study tested whether the processes in-
volved in encoding organizational or associative source could
occur without intention. Whether encoding organizational or
associative source requires considerable attentional resources or
whether it benefits from practice remains to be tested.
The findings that relative to associative source, organiza-
tional source might be encoded in a more automatic manner
through incidental learning does not comply with the predic-
tions by many other researchers, who argued that organizational
source should be encoded in a more effortful manner, since it is
extrinsic to the item and more intentional effort is required to
bind it to the item (Geiselman & Bjork, 1980; Baddeley, 1982;
Moscovitch, 1992; Spencer & Raz, 1995; Staresina & Davachi,
2008). This inconsistency might be due to the superiority of
learning and memory associated with location. Location changes
may involve eye movements, which may facilitate learning and
memory (Mayr, 1996) and counteract the interruption of main
task in the present study. Further investigation could focus on
the dissociation between associative sources and other organ-
izational sources, such as time.
Besides, the results of the present study could be used to ex-
plain the results from previous studies using incidental learning
task. Previous studies demonstrated that organizational source
accuracy was higher than associative source accuracy during
incidental learning (i.e., participants were not informed what
Copyright © 2013 SciRes. 679
would be tested later and the related source was not a part of
the demand of encoding task) (Staresina & Davachi, 2008,
Uncapher et al., 2006). Based on the present results, it is sug-
gested that organizational source is encoded concurrently with
the main task, which produces significantly higher performance
than associative source. Consistently, our data also showed that
organizational source accuracy was higher than associative
source accuracy in the item-oriented task (t(13) = 6.07, p < .05
with Bonferroni correction for multiple comparison).
It should be noted that the results of the present study could
not merely be explained by congruency effect. According to
congruency effect, congruous items eliciting “yes” answers
(e.g., “is ELEPANT animate?”) will result in better subsequent
memory than incongruous items eliciting “no” answers (e.g.,
“is TABLE animate?”, e.g., Schulman, 1974; Craik & Tulving,
1975; Staresina et al., 2009), because unlike incongruous items,
the congruous items have a preexisting relationship with the
question context. This relationship is thought to prompt addi-
tional relational binding processes to combine the context and
the item as an integrated unit, which in turn strengthens the
memory trace. The present study found the location-oriented
task and the color-oriented task produced more “YES” re-
sponses than the item-oriented task, which might foster addi-
tional relational binding processes and strengthen the memory
trace. However, although the source accuracy in the color-ori-
ented task was higher than in the item-oriented task, such supe-
riority in source memory did not appear for the location-ori-
Finally, it should also be noted that the results of the present
study might not be strategy-derived. The present experiment
used a mixed trials approach at encoding phase (i.e., asking
participants to make different types of judgments from trial-to-
trial), which might lead participants to more intentionally en-
code all aspects of the stimulus in each trial and develop strate-
gies relating to the perceived importance of location, color, and
animacy. Correspondingly, one might argue that the present
results might be strategy-derived, rather than truly representing
the difference between incidental and intentional encodings.
However, our experimental methods rule out such possibility.
In the experiment, the frequency of each task (1/3) remains the
same during encoding phase. Such manipulation, which has
been informed to the participants before the experiment, might
result in equal perceived importance of three aspects (location,
color, and animacy).
In sum, the present findings suggested that associative source
might be encoded in more effortful way, whereas processing of
organizational source might be performed incidentally.
This research was supported by National Natural Science
Foundation of China (31100728), Projects Planning in Shang-
hai Philosophy and Social Sciences Research (2012JJY001).
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