RUNNING HEAD: ATTENTION AND AWARENESS OF LOCATION AND IDENTITY

Does Attention Accompany the Conscious Awareness of Both Location and Identity of an Object?

Shahab Ghorashi, Lisa N. Jefferies
University of British Columbia
Jun-ichiro Kawahara
National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
and
Katsumi Watanabe
The University of Tokyo

Key words: attention, consciousness, spatial attention, identification, localization, attentional blink,shooting-line illusion

Correspondence to:
Shahab Ghorashi
Department of Psychology
University of British Columbia
2136 West Mall
Vancouver, BC V6T 1Z4
Canadae-mail: ghorashi@psych.ubc.ca
Phone: 604-822-6634

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Abstract
The question of whether consciousness and attention are the same or different phenomena has
always been controversial. In trying to find an answer to this question, two different measures forconsciousness and attention were used to provide the potential for dissociating between them. Conscious
awareness of either the location or the identity of the object was measured as the percentage of correct
reports of that aspect. The location of the focus of attention, on the other hand, was determined using theshooting-line illusion (SLI). In the SLI, a static line is perceived as growing from the location of apreceding cue (i.e., the location of the focus of attention). To investigate whether conscious awareness of
the location of an object could be dissociated from conscious awareness of its identity, the attentional
blink (AB) was used. It is known that during the AB, identification of the second of two consecutively
and briefly presented targets (T1 and T2) is impaired if the temporal lag between the two targets is lessthan about 500 ms. In three experiments, an SLI was induced during the AB to determine whether
attention was at the location of T2 when the observer was consciously aware of its location, its identity, orboth. Observers were instructed to report the identity and location of the targets, and the direction of the
SLI. Three important findings emerged. First, the SLI was seen as growing from T2 only when T2 was
identified correctly. Second, observers could report T2 location even when unaware of its identity.
Third, the SLI occurred from T2 only when T2 identity – not its location – could be reported correctly.
These results indicate that focal attention does not necessarily accompany conscious awareness of some
aspects of the object, while it does accompany conscious awareness of its identity.

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It can readily be argued that attention and consciousness are tightly interlinked and serve parallel
functions in our day-to-day experience. Attention, for instance, is selective, excluding objects or
locations that fall outside its focus. Those unattended objects or locations are seen less clearly, processed
less well, and reacted to more slowly than they would be if attended. Consciousness can be argued toserve a similar selective function – we are never aware of all of the information available to us in theworld, and we are provided with a filtered view of that world by the information that does reach ourconsciousness.
There is substantial evidence to support the proposal that consciousness and attention are
inseparably linked (e.g., Dehaene et al., 2006; Taylor & Fragopanagos, 2007). Consider, for example, thephenomenon of change blindness in which observers watch repeated alternations of two versions of asingle photograph, in which one element in the photo is different in the two versions. The task is simply
to identify what is changing; that change can be quite substantial, such as the disappearance andreappearance of the engine in a photograph of an airplane. It has been shown that in this task, the change
is only detected when attention is directed specifically to the element that is changing. In other words,
without attention, the element does not reach conscious awareness and hence the change is not detected(O’Reagan et al., 2000; Rensink, 2000; Rensink, O’Reagan, & Clark, 1997; Simons & Levin, 1997;
Simons & Rensink, 2005). Mack and Rock (1998) reported the phenomenon of inattentional blindness inwhich objects which are not attended, even when substantial and surprising, do not reach conscious
awareness. Given evidence such as this, many have concluded that attention and consciousness are one
and the same.
Other scientists and philosophers, however, have questioned whether it is justified to say that
attention and consciousness are inseparably linked. Is it really necessary to pay attention to something inorder for it to reach consciousness? Can items which have not reached consciousness attract attentional
processes? Research has shown that observers can become conscious of an isolated object or the gist of ascene despite the near absence of top-down attention; conversely, observers can attend to perceptuallyinvisible objects which do not reach consciousness (Koch & Tsuchiya, 2007). Along the same lines,
stimuli that are attended are not always consciously perceived (Super et al., 2001).
Given the continued debate as to whether attention and consciousness are linked at theoretical andconceptual levels, it is especially difficult to dissociate them at an empirical level (Koch & Tsuchiya,2007). This is particularly true when one considers the phenomenological diversity of both attention andconsciousness as well as the dynamic nature of the attention-consciousness relationship. In this sense,
dissociating attention and consciousness is one of the items in the list of fundamental problems in thefield. To answer this question, some recent studies have used procedures that manipulate consciousness
and attention independently, and the current research follows this trend.
In the present paper, we will build on the distinction between conscious awareness of the locationof an object and conscious awareness of the identity of that same object as proposed by Atkinson and
Braddick (1989). Further, we will use an index of attention that will enable us to distinguish whether
attention accompanies both aspects of conscious awareness (suggesting that attention and conscious
awareness are fully linked) or whether conscious awareness of the location of an object and conscious
awareness of its identity are differentially accompanied by attention (suggesting that attention andconscious awareness can be dissociated). In determining whether attention accompanies conscious
awareness of both location and identity, we employed two separate measures, one for attention and one
for consciousness. Specifically, we utilized the attentional blink (AB) paradigm to manipulate theobservers’ conscious awareness of the identity of an object, and the shooting-line illusion (SLI) to index
the location of attention.
In a rapid serial visual presentation (RSVP) when there are two targets (T1 and T2) embedded ina stream of distractors and the task is to report those two targets, a deficit in the perception of the second
target is usually observed if the inter-target lag is not longer than about half a second (e.g., Chun & Potter,
1995; Raymond, Shapiro, & Arnell, 1992). Most studies on this phenomenon, known as the attentional
blink, have shown that what was impaired during the AB was the identification (e.g., Potter, Chun,
Banks, & Muckenhoupt, 1998) of the second target. The attentional blink is an ideal tool forATTENTION AND AWARENESS OF LOCATION AND IDENTITY

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manipulating an observer’s conscious awareness of the identity of a stimulus (Sergent, Baillet, &Dehaene, 1995) as the change from being aware of the identity of the stimulus to being unaware of its
identity appears to be an all-or-none process (Sergent & Dehaene, 2004). Hence, in the current
experiments we used the attentional blink in order to manipulate and measure whether or not theobservers were consciously aware of the identity of the target stimuli.
In the current research we used a second phenomenon known as the shooting-line illusion toindex the location of attention. In the SLI (Hikosaka, Miyauchi, & Shimojo, 1993a, b), a line that isdisplayed all at once is perceived as if drawn progressively from one end to the other. A temporallyleading cue – the inducing stimulus – is used to orient the observer’s attention to one end of the line, andthe line then appears to grow from that end. Hence, the SLI is critically dependent on attention being
focused at the location of the inducing stimulus, and we can therefore use the occurrence and direction of
the SLI to index the location of the focus of attention.
In combining the SLI and the AB to test the interaction between attention and conscious
awareness of identity and location, we built on the paradigm developed by Kawahara (2002). In his
study, Kawahara presented distractor digits in three separate RSVP streams located at the apices of animaginary triangle. Two of these streams also contained a letter-target. A line was also displayed
simultaneously with T2, and it could appear in one of three locations: 1) between the stream that
contained T1 and the stream that contained T2, 2) between the stream that contained T1 and the streamthat contained neither target, or 3) between the stream that contained T2 and the stream that contained
neither target. The results revealed a pronounced AB deficit in that T2 was identified more accurately ata long inter-target lag than a short inter-target lag. More importantly, observers perceived the line asshooting from the T1-stream regardless of whether the other stream contained T2 or a distractor. This led
to the conclusion that T1 acted as a spatial cue, which focused the observers’ attention on the location of
the T1-stream, thus mediating the SLI.
In this study, we use the same basic method as Kawahara (2002) did, to examine the observers’
conscious awareness of the location of the target, conscious awareness of the identity of the target, andwhether attention accompanied both forms of conscious awareness. The critical difference between thecurrent experiments and those of Kawahara (2002) is that the inducing stimulus was T2 instead of T1 sothat we could use the attentional blink to control whether observers had conscious awareness of theidentity of T2. Specifically, at short inter-target lags, observers would not be consciously aware of theidentity of T2 whereas at long inter-target lags they would be.
EXPERIMENT 1A
The current research aims to separate the conscious awareness of the identity of a stimulus fromthe conscious awareness of its location, and to determine whether attention equally accompanies bothaspects of conscious awareness. Given that we use the attentional blink in order to achieve this goal, we
must first confirm that the SLI can occur in response to a correctly-identified T2 as the inducing stimulus
as it did when T1 was the inducing stimulus in Kawahara’s (2002) experiment. Hence in Experiment 1A,
we ask the participants to report the identity of T1 and T2, and to report the direction towards which they
perceive the line as growing. Correct identification of T2 indicates conscious awareness of its identity
while the occurrence of the SLI indicates that attention was focused on T2’s location.
MethodObservers
Twelve University of British Columbia undergraduates participated for course credit.
Apparatus and Stimuli
Observers viewed a computer display from a distance of 57 cm. The targets (upper-case letters,
except for I, O, Q, and Z) and distractors (digits 1-9) subtended 1° of visual angle. All stimuli were white
on a black background and were displayed at the corners of an imaginary equilateral triangle inscribedwithin an imaginary circle of 1.5° radius. A line segment was presented along one of the sides of theimaginary triangle.

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Procedure
Each trial began with the presentation of a fixation cross. After a delay of 500-1000 ms, threesynchronized RSVP streams were displayed, such that in every frame there was one item at each corner ofan imaginary triangle (Figure 1).
The stimuli in each frame weredifferent from one another and from the stimuli
in the two preceding frames. Each frame wasdisplayed for 30 ms, followed by an inter1
11
stimulus interval (ISI) of 70 ms during which
5 4
5 4
5 4
the fixation screen was displayed. There were
6-10 distractor-frames preceding T1. In three9
T1-T2
T2-D
T1-D
quarters of the trials, T2 was displayed directly
6 3
after T1 (in the ordinal position known as Lag
Probe1). This was done to maximize the number oflinetrials on which T2 was likely to be missed. In
4
the remaining trials, T2 was displayed 700 ms
7
2
after T1 (in the ordinal position known as Lag7), with intervening distractors continuing to be7
T2
presented during the longer inter-target lag. T1
K 8
and T2 were never presented at the same
T1
location on any given trial. The RSVP streams
G
Lag
continued for an additional 3-6 frames after T2.
4 6(100,700ms)
On the third frame after T2, the line was2
presented for 30 ms along one side of the
8 5
imaginary triangle in one of three possible
locations: between the two target-streams (theInter-Target condition), between the T1- andthe distractor-stream (the T1-D condition), or
between the T2 stream and the distractor stream(the T2-D condition). At the end of each trial,
Figure 1. Schematic diagram of the sequence ofobservers reported the identity of T1 and T2,
events in the experiments.
and were required to judge the direction inwhich the line appeared to grow. Each observer
completed 10 practice trails and 288
experimental trials.
Results and Discussion
Mean accuracy for T1 was 90.3%. Mean accuracy for T2 was 55.6% at Lag 1 and 87.9% at Lag
7. A paired-samples t-test revealed a significant AB deficit, t(11) = 9.38, p<0.001.
The results for the SLI are summarized in Figures 2a and 2b. The critical issue is whether the line
was seen as shooting from the location of the T2 stream on trials in which T2 was correctly identified. As
expected, the line was seen as shooting from T2 only on trials in which T2 was identified correctly(Figure 2a), z = 4.50, p < .001 (T2-D condition), and z = 3.19, p < .001 (Inter-Target condition). On trials
in which T2 was missed (Figure 2b), the line was seen as shooting either to or from T2, at chance, z =0.54, (n. s., T2-D condition) and z = 1.17, (n. s., Inter-Target condition).
The T1-D condition was analyzed to verify that the SLI is obtained from an attended target,whether the target is T1 or T2. As expected, in this condition the line was seen as growing from T1
regardless of whether T2 was identified correctly (Figure 2a; z = 2.83, p < .005) or incorrectly (Figure 2b;z = 4.89, p < .001).
This pattern of results strongly suggests that the line was seen as originating from the location of
T2 only when T2 was identified correctly. In the present experiment, however, we did not analyze thedata from Lag-7 trials because of their scarcity. To make sure that the results from Lag-7 trials are inATTENTION AND AWARENESS OF LOCATION AND IDENTITY

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accordance with the results of Lag-1 trials, in the next experiment the number of Lag-7 trials is increased
from one-quarter to three-quarters of trials.
EXPERIMENT 1B
In Experiment 1A, the results from the Lag-7 trials were not analyzed because they comprised
only 25% of the trials. Therefore, a separate experiment was conducted in which 75% of the trials were
Lag-7 trials. This was done with two objectives in mind. The first objective was to check on theconsistency of the SLI at Lag 7 and Lag 1, namely, whether the SLI is obtained only when T2 is identified
correctly at Lag 7, as was the case for Lag 1 in Experiment 1A. The second objective was to investigate
the temporal course of the SLI across inter-target lags. We expected that by Lag 7 the SLI would nolonger originate from the location of T1 because, by that point in time, the attentional focus would befully relocated from T1 to T2.
MethodTwelve experimentally naïve observers participated in this experiment. The methods wereidentical to those of Experiment 1A except that on 75% of the trials T2 was presented at Lag 7.
Results and Discussion
Mean accuracy for T1 was 88.4%. Mean accuracy for T2 was 49.6% at Lag 1 and 87.8% at Lag
7. A paired-samples t-test revealed a significant AB deficit, t(11) = 11.7, p < 0.001.
The pattern of the SLI results (Figures
2c and 2d) was similar to that in Experiment
T2 correct
T2 missed
1A, except that the direction of the SLI in theab
T1-D condition was at chance levels. Namely,
T1
T1
there was no tendency to see the line as
growing from T1. This is because, by Lag 7,
Lag 1
processing of T1 has been completed, and the(Experiment 1a)
attentional focus has been repositioned to theT2 60 40 D
T2 51 49 D
location of T2.
In Experiments 1A and 1B, wecdobserved that the SLI is perceived to originate
T1
T1
from the location of T2 when (and only when)
the identity of T2 is reported correctly. Hence,
Lag 7
in Experiment 1A we confirmed that the SLI(Experiment 1b)
can occur in response to a T2 as the inducing
T2 68 32 D
T2 48 52 D
stimulus, indicating that when the observer isconsciously aware of the identity of T2,
attention is focused at T2’s location. The goalof the current research is to separate the
Figure 2
conscious awareness of the identity of a
Figure 2. Shooting-Line Illusion results ofstimulus from the conscious awareness of its
Experiments 1A and 1B. Each arrow and its
location in order to determine whether attention
number represent the percentage of trials inequally accompanies both aspects of conscious
which the SLI was perceived as originatingawareness. As such, it is also necessary tofrom the item in the tail of the arrow growing
assess whether the attentional blink, which
towards the item to which the head is pointing.
renders the observer unaware of the identity ofArrow pairs in which one arrow is black
the target at short inter-target lags, can leave theindicate proportions that are significantly
conscious awareness of the location of thatdifferent from chance.
target intact. We tested this in Experiment 2, in
which observers were required to report not
only the identity of T2, but also its location.
If the attentional blink functions in the intended manner, then on some portion of those trials in which theidentity of the second target does not reach conscious awareness, the observer should still be consciously

ATTENTION AND AWARENESS OF LOCATION AND IDENTITY

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aware of the location of that target. This would be indexed by an incorrect report of T2-identity
accompanied by a correct report of T2-location.
EXPERIMENT 2
In Experiments 1A and 1B, we showed that the SLI occurs from T2 only when T2 is identified
correctly. The next step is to investigate whether conscious awareness of the location of T2 can occur
without conscious awareness of its identity during the AB. If this is the case, we will be able to dissociate
the two levels of conscious awareness. To this end, the same stimuli and almost the same procedure as in
the previous experiment were used, except that observers were required to report the identity and locationof the first and second targets (T1 and T2), and to ignore the line.
MethodExperiment 2 was the same as Experiment 1A, except that 12 observers reported the identity andlocation of T1 and T2, and were asked to ignore the line. In this experiment, as in Experiment 1A, T2
was displayed directly after T1 (Lag 1) in three-quarters of the trials. In the remaining trials, T2 wasdisplayed at Lag 7.
Results and Discussion
Only trials in which T1 was identified correctly were analyzed. Mean accuracy for T1 was
88.1%. A significant AB deficit was obtained: T2 accuracy was 63.6% at Lag 1 and 87.4% at Lag 7;
t(11) = 7.02, p<0.001.
Of the 36.4% of trials in which T2 was missed at Lag 1, observers reported its location correctly
62.9% of the times. Hence, even when the observers failed to identify T2, they could report its location asignificant proportion of the time, z = 7.10, p < 0.001. It needs to be stressed that T2 could be localized
without being identified on a relatively modest proportion of the trials (12.9%) beyond the 50% chancelevel. To wit, this was a relatively infrequent event. Nevertheless, it exceeded the chance level by amargin that was highly significant, attesting to its reliability. This previously unreported finding strongly
suggests that, during the AB, the blinked target is processed to an extent sufficient to extract spatial
information but not identity information.
This conclusion may be questioned, however, because when T2 identity was missed but its
location was reported correctly, observers might have known that a letter was presented at that location
but could not identify it, perhaps because it belonged to a highly confusable pair (e.g. E-F). We addressed
this possibility, by constructing a confusion matrix involving all 22 stimulus letters and 22 response
letters. Given the above hypothesis, most of the 965 errors (summed over all trials and observers) should
involve highly confusable letter pairs, such as E and F. On the contrary, we found that most errors (109)
occurred upon presentation of J (confused mostly with D, G, H, R, S, Y) and S (92 errors, confused with
H, K, L, T, Y). The letter F was confused with E seven times, and E with F only four times. Clearly,
confusions occurred not between similar letter pairs but between letters and digit distractors (J with 1, S
with 5 or 8). Notably, errors primarily involved pressing a key in or near the home typing positions on
the keyboard. We conclude that correct localization was not an artefact arising from confusable letter
pairs.
In general, the conclusion from Experiment 2 is that during the AB, conscious awareness of thelocation of T2 is sometimes preserved even when conscious awareness of its identity is not. That is, ourmanipulation for dissociating the two levels of conscious awareness was successful. From Experiment
1A we remember that the SLI is seen as growing from T2 only when the identity of T2 is reported
correctly. In other words, the focus of attention accompanies conscious awareness of the identity of an
object. By combining Experiments 1A and 2, we investigate whether the focus of attention also
accompanies conscious awareness of the location of an object.
EXPERIMENT 3
Experiments 1A and 1B confirmed that the SLI can be used to index whether or not the focus ofattention has been shifted to T2. Experiment 2 further established that the attentional blink enables us toseparate the conscious awareness of the identity of T2 from the conscious awareness of T2’s location.
Experiment 3 is the key experiment in this study, and observers were required to report the identity andlocation of both targets, as well as the direction of the SLI. This allows us to probe whether attention

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accompanies the conscious awareness of the identity of T2 (i.e., when T2 is correctly reported) andseparately whether it accompanies conscious awareness of the location of T2 (i.e., when T2 wasincorrectly identified but correctly localized). If the SLI is seen to emanate from the location of T2 inboth cases, attention can be said to accompany conscious awareness of both location and identity; if the
SLI is seen to emanate from the location of T2 when it can be correctly identified, but not when it can
only be correctly localized, then attention can be presumed to accompany the conscious awareness of theidentity of an item, but not the conscious awareness of the location of that item.
MethodExperiment 3 followed the same procedures as Experiments 1A, 1B, and 2, except that the 13
observers reported SLI direction, the identities of the two targets, and their locations, in that order. To
maximize the number of trials on which T2 was likely to be missed (the only condition in which
conscious awareness of location can be dissociated from conscious awareness of identity), T2 was always
presented at Lag 1.
Results and Discussion
Mean accuracy for T1 and T2 was 86.7% and 60.7%, respectively. The results for the SLI aresummarized in Figures 3. When T2 was identified correctly, the pattern of the SLI results was similar tothat in Experiments 1A and 1B (see Figures 2a and 3a).
The line was seen as shooting from T2T2 correct
T2 missed
only on trials in which T2 was identified
correctly (Figure 3a), z = 4.89, p < .001 (T2-Dab T2 location correct
condition), and z = 2.56, p < .01 (Inter-Target
T1
condition). Critically, when T2 identity was
missed, but its location was reported correctly,
the SLI did not originate from T2 (Figure 3b).
T1
Specifically, in the Inter-Target condition theline appeared to shoot from T1 (z = 3.57, p <T2 55 45 D
.001), and in the T2-D condition, the line Lag 1(Experiment 3)
appeared to shoot either from T2 or from thec T2 location missed
distractor, at random (z = 1.57, p > .05). This
T2 60 40 D
T1
supports the conclusion that attention
accompanies the conscious awareness ofidentity, but not the conscious awareness oflocation.
As expected, in the T1-D condition, theT2 54 46 Dline was seen as shooting from the location of
T1 irrespective of T2 report (in Figure 3a, when
T2 identity was correct, z = 2.52, p < .01; in Figure 3. Shooting-Line Illusion results of Experiment 3.
Figure 3b, when T2 identity was missed andEach arrow and its number represent the Figure
percentage
3
when T2 location was correct, z = 2.16, p < .01;
of trials in which the SLI was perceived as originating
and in Figure 3c, when T2 identity and locationfrom the item in the tail of the arrow growing towards
were missed, z = 3.18, p < .005). This pattern
the item to which the head is pointing. Arrow pairs inof results is consistent with that of Experiment
which one arrow is black indicate proportions that are
1A, suggesting that, at shorter inter-target lags,significantly different from chance.
the attentional focus has not fully disengaged
from the location of T1 and, therefore, the SLI
is perceived as originating from that location.
General Discussion
Two important findings emerged from the present study. First, observers were able to report thelocation of a target even when they were unaware of its identity. This finding may speak to the issue of
whether mental representations are graded (Farah, 2000; Kanwisher, 2001) or all-or-none (Sergent &Dehaene, 2004) in nature. Specifically, given that mental representations of target objects are presumed
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to contain both spatial and identity information, and given that the current research shows that spatial
information can be independently registered prior to identity information, this suggests that mental
representations are graded in nature. As such, an account of our findings can be couched in the findingthat coarse spatial information about a target becomes available before its identity (Atkinson & Braddick,
1989; Huang & Pashler, 2007; Sagi & Julesz, 1985). This means that observers would know that a letter
had been presented in a given stream (i.e., at a given location) before knowing the identity of that letter.
This alone, however, does not explain why observers could report the location of T2 but not its identity.
To account for this finding, we need an additional factor: backward masking. In the RSVP stream, T2
was always followed 100 ms later by a mask (the trailing distractor) which interrupted its processing(Breitmeyer, 1984). On trials in which the location of T2, but not its identity, was reported correctly, themask may have arrived after location information had been extracted but before identity information
could be fully processed. Thus, coarse location information escaped masking, but identity information
was impaired.
The second important finding was that the SLI was obtained only when T2 was identified
correctly. Knowledge of the location of T2 without knowledge of its identity was not sufficient formediating the illusion. An account consistent with the foregoing discussion can be given in terms ofspatial gradients of activation. It has been argued that the SLI results from faster visual processing at thelocus of attention (Schmidt & Klein, 1997; von Grunau, Saikali, & Faubert, 1995). It has further been
proposed that the mechanism underlying this illusion is a spatial gradient of facilitation that forms aroundthe cue, with the amount of facilitation being greatest at the center of the gradient (Hikosaka, Miyauchi, &Shimojo, 1996). Hence, signals from locations closer to the cue reach the motion sensors in the brain
faster than signals from locations farther from the cue. This causes the line to be seen as growing fromthe end closer to the cue.
The gradient of facilitation has been shown to develop gradually: It begins by being relatively
shallow, and becomes progressively steeper as a function of processing time since the presentation of thecue (Miyauchi, 1997). Our account of why the SLI was not seen when T2 was missed is based on two
assumptions. First, we assume that the arrival of the mask cuts short both the identification of T2 and thedevelopment of the spatial gradient. Second, we assume that the rate at which the gradient develops andT2 is processed fluctuates from trial to trial. On these assumptions, we suggest that, on trials in which T2
was missed, processing was relatively slow, and the mask interfered with both T2-identification and thedeveloping gradient of facilitation. As a consequence, the gradient did not develop to the required
steepness, and the illusory motion from the location of T2 failed to be seen. In contrast, on trials in which
T2 was identified correctly, we assume that processing was faster thus allowing the gradient of facilitation
to develop to a steepness capable of mediating the SLI before the arrival of the mask.
The principal objective of this study was to investigate whether conscious awareness of an aspectof the object – in this case, its location – could be attained before attention was oriented to that location.
To this end, two operational definitions and thus, two different measures were used for consciousness andattention. We measured conscious awareness of the aspect of the object by the percentage of correct
responses to that specific aspect (e.g., location or identity), and we found the location of the focus ofattention by determining where the SLI originated from. Combining these two different measures forconsciousness and attention provides the potential for dissociating between consciousness and attention,and for investigating whether focal attention accompanies conscious awareness of the location or of theidentity of an object, or both. As discussed above, the results showed that the conscious report of thelocation of an object can take place before either attention to that location or the conscious report of theidentity of that object can occur.
On the face of it, this conclusion seems to be consistent with the model suggested by Lamme(2003). In his model, Lamme proposes that observers are conscious of a great deal of visual input, but
only at a “phenomenal” level (Block, 1996). Of those visual inputs, some that are related to the task at
hand go through the attentional processes for selection. Only a subgroup of the attended stimuli,
however, will reach consciousness at the “access” level. In the current study, though, it is shown thatsome aspects of the object can reach access awareness even before attentional processes are involved.

ATTENTION AND AWARENESS OF LOCATION AND IDENTITY

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This leads us towards the more fundamental questions such as whether attention andconsciousness are each a unitary phenomena or whether they each consist of several different aspects. To
address these questions, before proposing detailed functional imaging studies, careful examinations ofphenomenological and behavioural effects are warranted. This is because differential brain processes do
not necessarily mean differences in subjective phenomenology and behaviour. Only after we sort out
phenomenological and behavioural effects can we map those into brain processes.

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Author Notes
This work was supported by National Sciences and Engineering Research Council of Canada awards to
S.G. and L.N.J., and by a Japan Society for the Promotion of Science grant to J.K.

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