Cognitive Brain Research 12 (2001) 131–144
www.elsevier.com / locate / bres
Research report
Simultaneously active pre-attentive representations of local and global
rules for sound sequences in the human brain
´
´ a , *, Istvan
´ Czigler a , Elyse Sussman b , Istvan
´ Winkler a,c
Janos
Horvath
a
Institute of Psychology, Hungarian Academy of Sciences, H-1394 Budapest, P.O. Box 389 Szondi u. 83 /85, Budapest, Hungary
b
Department of Otolaryngology, Albert Einstein College of Medicine, New York, NY, USA
c
Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Helsinki, Finland
Accepted 27 February 2001
Abstract
Regular sequences of sounds (i.e., non-random) can usually be described by several, equally valid rules. Rules allowing extrapolation
from one sound to the next are termed local rules, those that define relations between temporally non-adjacent sounds are termed global
rules. The aim of the present study was to determine whether both local and global rules can be simultaneously extracted from a sound
sequence even when attention is directed away from the auditory stimuli. The pre-attentive representation of a sequence of two alternating
tones (differing only in frequency) was investigated using the mismatch negativity (MMN) auditory event-related potential. Both localand global-rule violations of tone alternation elicited the MMN component while subjects ignored the auditory stimuli. This finding
suggests that (a) pre-attentive auditory processes can extract both local and global rules from sound sequences, and (b) that several
regularity representations of a sound sequence are simultaneously maintained during the pre-attentive phase of auditory stimulus
processing.  2001 Elsevier Science B.V. All rights reserved.
Theme: Neural basis of behavior
Topic: Learning and memory: systems and functions
Keywords: Auditory event-related potentials; Mismatch negativity; Regularity representation; Temporal organization
1. Introduction
In everyday life, sounds are usually encountered within
sequences of inter-related auditory events. Therefore, the
sequential organization of sensory information is a key
element of auditory perception. Organization is achieved
through the formation of ‘links between parts of the
sensory data’ (Bregman, 1990, p. 47 [4]), which gives rise
to the segmentation of the auditory environment. The
processes associating sounds according to various auditory
organization principles could take place at different stages
of information processing. Bregman’s [4] theory of auditory stream segregation assumes that several of the possible
ways of linking sounds together are examined in parallel
during the early, possibly pre-attentive phases of auditory
information processing. We tested the hypothesis that both
*Corresponding author.
´
E-mail address: horvath@cogpsyphy.hu (J. Horvath).
the local and global types of links are formed during the
pre-attentive stages of auditory processing.
Regular sequences of sounds (i.e., non-random) can
usually be characterized by more than one rule. One may
classify these rules on the basis of their temporal scope.
Local rules describe relations between temporally adjacent
stimuli, global rules describe relations between temporally
non-adjacent stimuli [4]. Simple sound sequences can be
described in terms of both local and global rules. For
example, the local rule for a sequence of two alternating
tones (‘ . . . ABABAB . . . ’) would say that A is always
followed by B and B is always followed by A. One
possible global rule describing the same sequence would
maintain that every second tone is A while every other is
B.
Another categorization of rules can be made on the basis
of whether a rule is concrete (i.e., enables extrapolating
from a specific sound to another specific sound) or abstract
(i.e., enables extrapolating from one class of sounds to
0926-6410 / 01 / $ – see front matter  2001 Elsevier Science B.V. All rights reserved.
PII: S0926-6410( 01 )00038-6
132
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
another class of sounds; abstract rules define relationships
between sets of sounds). In the above example of the two
alternating tones, both rules are concrete as they apply to
the two specific tones of the alternating sequence. An
abstract rule describing (frequency) alternation, in general,
would state that the two neighbors of a sound in the
sequence have either both higher or both lower pitch than
the sound itself.
Finally, a distinction which is relevant for theories of
auditory information processing: a rule may apply to
stimuli as integrated events (‘event-rules’) or only to
certain sound features (‘feature-rules’). Local and global,
concrete and abstract rules may apply either to integrated
sound events or to levels of some sound feature(s). Our
first pair of examples were event-rules; the abstract rule
example was a feature rule. A global concrete feature rule,
which also applies to simple alternation, is that the time
from the onset of a tone to the onset of the next identical
tone is constant at a given stimulus onset asynchrony
(SOA) value.
The systematic formation of associations between
sounds in regular sequences can be regarded as a neural
representation of a rule. The question of what kind of rules
are represented for a given sound sequence in the absence
of focused attention by the human auditory system can be
studied using an event-related brain potential (ERP) component termed the mismatch negativity (MMN) [14] (for
recent reviews, see Refs. [28,16]). MMN is elicited by
sounds that violate some regularity of the preceding
auditory stimulus sequence, whether or not the subject’s
attention is focused on the auditory modality [13]. It has
been established that the discriminative MMN-generating
process involves an auditory sensory memory representation of the preceding regular sounds [12,21,16]. Winkler et
al. [36] suggested that MMN elicitation results from the
incoming sound mismatching the one(s) extrapolated from
the preceding auditory stimulus sequence. Therefore, if a
sound elicits the MMN, one can infer that some regularity
in the preceding sound sequence was pre-attentively
detected (this regularity being violated by the MMNeliciting auditory stimulus). Thus MMN enables one to
determine what rules are pre-attentively represented by the
auditory system for a given sound sequence. The regularities which have been shown to be detected during the
pre-attentive phase of auditory information processing
range from simple repetition rules (e.g., Ref. [14]) to
sensory trends [33] and regularities of complex sequential
or spectro-temporal sound patterns (e.g., Refs. [18,25]).
MMNs elicited by violations of concrete as well as abstract
rules (e.g., Refs. [14] and [23], respectively), event as well
as feature rules (e.g., Refs. [37] and [8], respectively) have
already been observed. However, no previous study has
made a direct test of whether global rules can be represented nor did they distinguish between repeating patterns
and the global structure of non-adjacent tones.
2. Experiments
The aim of the present study was to investigate whether
(a) global rules can be pre-attentively extracted and (b)
different kinds of rules (such as global and local, concrete
and abstract) can be simultaneously represented by the
pre-attentive auditory information processing system. The
main test sequence (Experiment 1) was a simple alternation of two tones (see Fig. 1). As was described above,
such a sequence can be characterized by several different
rules, amongst them both local and global ones. Previous
studies (e.g., Refs. [1,18]) demonstrated that occasional
repetitions of one of the two alternating tones
(‘ . . . ABABAA . . . ’) elicit the MMN even when subjects
ignore the auditory stimuli. This means that some regularity or regularities describing this tone alternation were
pre-attentively represented in the auditory system. However, these previous studies did not ask the question
whether the regularities underlying the elicitation of the
observed MMNs were local- or global-rule representations:
the tone repetition deviation, which was examined, simultaneously violates both the local and global rules. Testing
what kind of rules of alternation lie behind the observed
MMN responses is made possible by the fact that extrapolations based on local vs. global rules come up with
different results for the sound following an occasional
sound repetition. According to the local rule, A is followed
by B and B is followed by A; therefore, if the local rule
returns after a sound repetition, this repetition should
be followed by changing to the other sound
(‘ . . . ABABAAB . . . ’). In contrast, according to the global rule, each sound is identical to the sound two back in the
sequence; therefore, for the global rule to return, the sound
following a repetition should be identical to the repeated
sound (‘ . . . ABABAAA . . . ’). Since sounds violating
Fig. 1. The stimulus sequence presented in Experiment 1. The two alternating tones differed only in frequency (1000 and 1100 Hz). The different types of
deviants are marked by different fillings.
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
some pre-attentively detected regularity elicit the MMN
component, the ERP responses to the two possible continuations of the alternating sequence following an occasional stimulus repetition will indicate whether the preattentive MMN-generating process was based on the local
or a global alternation rule. If both types of rules are
simultaneously used in the MMN-generating process,
neither or both continuations should elicit the MMN
(depending on whether violation of one rule supersedes
compliance with another rule or not).
2.1. Experiment 1
2.1.1. Subjects and procedure
Thirteen paid subjects (nine females; 16–24 years of
age) with normal hearing participated in the experiment.
Subjects gave informed consent after the nature of the
experiment was explained to them. The subject was
comfortably seated in an acoustically shielded room. He /
she was instructed to ignore the sounds and read a selfselected book. The experiment consisted of ten stimulus
blocks, each 8.4 min long, with 1–2 min rest between
consecutive blocks.
2.1.2. Stimuli
Stimuli were pure sinusoidal tones presented binaurally
through headphones with an SOA of 500 ms at 70 dB
(SPL). The stimulus duration was 100 ms (including 5 ms
rise and fall times). Two tones differing only in frequency
(1000 and 1100 Hz) were alternated (‘ . . . ABAB . . . ’).
Stimulus blocks consisted of 1010 tones. In each block, the
pattern of alternation was violated 40 times by repeating
either one of the tones with equal probability. Henceforth,
tone repetitions (which violate both local and global rules)
will be referred to as ‘both-rules deviants’. After half of
the both-rules deviants, the sequence continued with a
change between the two tones: ‘ . . . ABABAAB . . . ’ or
‘ . . . BABABBA . . . ’. This type of continuation violates
the global, but not the local rule (see above); hence we
term the change following a single tone repetition ‘globalrule deviant’ (see Fig. 1). Following the other half of the
both-rules deviants, the sequence continued with another
repetition of the same tone: ‘ . . . ABABAAA . . . ’ or
‘ . . . BABABBB . . . ’. This type of continuation violates
the local, but not the global rule (see above); hence we
term the second consecutive tone repetition ‘local-rule
deviant’. Each both-rules deviant was preceded by at least
5 regularly alternating tones. Although this puts some
restriction on the randomness of the sequence, the low
probability of deviants allow sufficient number of variations that the length of possible cycles in the stimulus
sequence would still fall, by far, outside the capacity of
auditory memory. Overall, responses to 103405400 bothrules deviants and half as many local- and global-rule
deviants were recorded from each subject.
133
2.1.3. EEG recording
EEG was recorded (DC-40 Hz, sampling rate 250 Hz,
Synamp amplifiers, NeuroScan EEG recording system)
with Ag /AgCl electrodes placed on five locations on the
midline (Fpz, Fz, Cz, Pz, Oz), by the two mastoids (Lm,
Rm), and at the one- and two-third points of the arc
connecting Fz and the mastoids over both hemispheres
(L1, L2 and R1, R2 on the left and right scalp, respectively). The common reference electrode was attached to the
tip of the nose. The horizontal electro-oculogram was
recorded using a bipolar configuration between electrodes
positioned near the outer canthi of the two eyes. The
vertical EOG was recorded with a bipolar configuration
between electrodes placed above and below the right eye.
2.1.4. Data analysis
EEG was off-line bandpass filtered in the 1.5–20 Hz
range and epoched between 290 and 490 ms from
stimulus onset. The first ten epochs of each block and
epochs containing an amplitude change exceeding 75 mV
on any EEG or EOG recording were rejected from further
analysis. ERP responses were averaged separately for
‘standards’ (regularly alternating tones following at least
two cycles of undisturbed alternation), both-rules deviants,
local-rule deviants, global-rule deviants, and the first
change following a local-rule deviant (‘ABABAAAB’ or
‘BABABBBA’) which we term ‘repetition-rule deviant’
(see Fig. 1) as it may elicit an MMN if the preceding three
tones established a repetition rule (see Refs. [5,27,36]).
Responses elicited by the two different tones (A and B)
were collapsed in each of the above cases.
To estimate the full MMN amplitude (see Ref. [13]) for
statistical analysis, ERPs were re-referenced to the left
mastoid (Lm). Figures will, however, show the nosereferenced responses and differences separately for Fz and
Lm, for assessing the expected polarity inversion of the
MMN response. The amplitude measurements were referred to the average amplitude in the 90 ms pre-stimulus
interval. The MMN amplitude was calculated by subtracting the standard response from each of the four deviant
responses. Mean MMN amplitudes were measured from 24
ms wide intervals centered at the negative peaks observed
in the 100–200 ms post-stimulus interval of the grandaverage deviant-minus-standard differences. As the MMN
peak latency varies considerably with experimental parameters like the amount of deviance and the complexity of the
stimulation (see, e.g., Refs. [13,32]) and the temporal
extent of the component is relatively short, this widely
used method provides the best signal to noise ratio for
detecting the presence of the component. One-sided dependent t-tests were used to verify the presence of MMN.
The MMN amplitudes elicited by the both-rules, localrule, and global-rule deviants were analyzed by one-way
repeated measures ANOVA. Additivity of MMN responses
elicited by local- and global-rule deviants were tested by
one-way repeated measures ANOVA between the response
134
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
to both-rules deviants and the sum of responses to localand global-rule deviants (in the MMN range of the bothrules deviant response). The scalp topographies of the
MMNs elicited by the local- and global-rule deviants were
compared using two-way repeated measures ANOVA on
normalized data (to eliminate main effects that could
obscure possible interaction effects) in accordance with the
recommendations of McCarthy and Woods [10]; see also
Ref. [20]).
2.1.5. Results
Fig. 2 (left column) summarizes the grand-average nose-
referenced frontal (Fz) ERP responses to the standard and
the four deviant tones. A frontally negative waveform
peaking in the 100–200 ms post-stimulus latency range
can be observed for each of the deviant-minus-standard
difference curves (Fig. 2, right column). A reversal in
polarity of this negative deflection can be seen at the Lm
electrode site. The inversion of polarity below the Sylvian
fissure is a characteristic feature of the MMN component
[13], whereas the N2b component, which can also appear
in this latency range shows no such polarity inversion.
Grand-averaged MMN peak latency and amplitude measurements at Fz (re-referenced to Lm) and t-test results for
Fig. 2. Frontal (Fz) grand-average ERP responses (nose-referenced) to standard and deviant tones (left column) and the corresponding deviant-minusstandard difference curves at Fz and Lm (right column) in Experiment 1. Shading indicates the full (Lm-referenced) MMN component. Responses to the 4
different types of deviants are shown in different rows. First row: both-rules deviant (‘ . . . ABABAA . . . ’); 2nd row: local-rule deviant
(‘ . . . ABABAAA . . . ’); 3rd row: global-rule deviant (‘ . . . ABABAAB . . . ’); 4th row: repetition deviant (‘ . . . ABABAAAB . . . ’). The y-axis marks the
moment when the pattern-ending tone (marked by bold in the examples above) was delivered. For each type of deviant, responses were collapsed across the
two analogous patterns (obtained by exchanging the roles of A and B).
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
135
Table 1
Grand-average frontal (Fz, re-referenced to Lm) MMN peak latencies and mean amplitudes elicited by the four different deviants in Experiment 1 a
Deviant type
Stimulus-pattern
Peak latency (ms)
Peak amplitude
(mV)
t
(df512)
Both-rules
Local-rule
Global-rule
Repetition-rule
. . . ABABAA . . .
. . . ABABAAA . . .
. . . ABABAAB . . .
. . . ABABAAAB . . .
172.3
156.9
154.5
166.5
20.92
21.68
21.07
21.21
24.94**
25.91**
23.66*
24.59**
(3.9)
(3.5)
(3.5)
(5.0)
(0.18)
(0.29)
(0.29)
(0.26)
a
Standard errors of the mean are given in parentheses. The deviant tone for each deviant type is typeset in bold in the stimulus patterns. Standards were
regularly alternating tones following at least two cycles of undisturbed alternation. Both deviant and standard responses are collapsed across the two
analogous patterns (obtained by exchanging the roles of A and B).
* P,0.01.
** P,0.001.
all four deviants are given in Table 1. When a change
between the two tones was preceded by one or two tone
repetitions (Fig. 2, 3rd and 4th rows, respectively), an
earlier, frontally negative deviant-minus standard difference wave was also elicited, which was peaking close to
100 ms from stimulus onset (latency5100.067.7 ms
[6S.E.M], amplitude520.9360.28, t(12)523.34, P,
0.01 and 103.165.1 ms, 20.7360.18 mV, t(12)53.98,
P,0.001, for the global-rule and repetition deviants,
respectively). These early negative differences reflect an
increase of the N1 amplitude compared with that elicited
by regular alternation. Since both the global-rule and
repetition deviants are more separated in time from the
preceding identical tone (1400 and 1900 ms, offset to
onset) than the tones of the regular alternation (900 ms),
some of the frequency-specific N1-generator neuronal
elements become less refractory and, therefore, respond
more vigorously (see further Ref. [15]).
The MMN amplitudes across conditions (both-rules,
local-rule and global-rule) did not differ (one-way repeated
measures ANOVA, F(2,24)52.78, P,0.1). The MMN
amplitude elicited by the both-rules deviant was smaller
than the sum of the MMN amplitudes elicited by the localand global-rule deviants in the MMN-range of the bothrules deviant (F(1,12)510.51, P,0.01). There was no
difference in the scalp distribution of the MMNs elicited in
the local- and global-rules conditions (two-way repeated
measures ANOVA with factors of Condition [local- vs.
global-rule deviant] and Electrode [Fz, Cz, L1, Lm, R1,
Rm] on normalized data; F(5,60)50.68, P,0.6)
2.1.6. Discussion
The elicitation of MMN by both the local- and globalrule deviants suggests that local and global rules are
simultaneously represented in the pre-attentive auditory
information processing system. Deviants violating the local
but not the global rule could only elicit the MMN, if the
local rule was maintained even though subjects were
engaged in a task that was unrelated to the auditory
stimulus sequence. The fact that no N2b appeared in the
deviant responses confirms that subjects did not actively
attend the sound sequences, as in this case, deviants should
have elicited the N2b component [13,22,25]. If we could
conclude that the global-rule deviants elicited MMN
because they violated the global but not the local rule, the
simultaneous representation of the two types of rules
would be proven. However, four alternative explanations
can also account for the MMN elicited by global-rule
deviants:
1. Repeating a sound twice or more has been shown to
build up a representation of a repetition rule (i.e., the
recurrence of the same sound; [5,27,36]). Therefore it
is possible that even a single repetition of a sound may
be already sufficient for a subsequent change to elicit
the MMN component. This alternative explanation
would be compatible with a present result showing
that a change following two repetitions (three presentations) of one of the test tones (the repetition
deviant) elicited the MMN (Fig. 2, 4th row). Because
the repetition deviant violated neither the global nor
the local rule, it is very likely that the MMN elicited
by this deviant was based on violation of a repetition
rule which was formed as the auditory system was
presented with 3 consecutive identical tones. Therefore, the global-rule deviant, which is a change
following one repetition (2 presentations) of one of the
tones might reflect a similar phenomenon.
2. The MMN elicited by the global-rule deviant might be
an analogue of the MMNs observed for standard
stimuli which immediately followed a deviant
[24,19,36]. In the present case, the first repetition in
the alternating sequence is a deviant with respect to
the local rule, and the subsequent change (the globalrule deviant) is a standard with respect to this local
rule. Although the standard-following-a-deviant MMN
phenomenon has only been observed for repetition
rules, one cannot reject this alternative on the basis of
the Experiment 1 results.
3. It is also possible that the MMNs observed in Experiment 1 were elicited by infrequent changes in the
temporal schedule of stimulus presentation. One may
regard the alternating sequence as two separate repeti-
136
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
Fig. 3. Stimulus sequences presented in Experiment 2. Conditions are shown in different rows. Top row: Condition 1, sequences were equiprobably
randomized from twenty tones differing only in frequency. Middle row: Condition 2, increase in frequency was followed by decrease in frequency and vice
versa; the size of frequency change was random. Bottom row: Condition 3, two tones with 1000 and 1100 Hz frequencies were presented in an alternating
sequence with random (250–750 ms) SOA.
tive series of tones (one higher, the other lower) which
are interleaved with each other. Repeating a tone
violates the regular SOA of the series to which it
belongs (e.g., ‘ . . . ABABAA . . . ’ can be regarded as
‘ . . . A A AA . . . ’, an occasional reduction of the
regular SOA of the A series). Indeed, had the rate of
presentation been fast enough for the A and B tones to
form separate streams [4], this is how one would
perceive this event. Similarly, all of the present
deviants can be regarded as violations of the otherwise
isochronously presented higher / lower-tone series (if
these are processed separately). MMN was shown to
be elicited by occasionally shortening the SOA in an
otherwise isochronously presented sound sequence
[7,17]. It is, therefore, possible that the temporal
properties of the two sub-series are maintained preattentively and violations of the alternation of two
isochronously presented tones are detected as deviance
from these temporal regularities.
4. Finally 1 , the tones immediately preceding the globalrule deviant form a micro-sequence in which the
occurrence of the repeated tone is higher than that of
the other tone (e.g. in the case of the preceding 4 tones
–‘ABAA’-A is presented in 75% of the stimuli).
Micro-sequences with unequal probabilities for the
two tones have been shown to elicit MMN in 50–50%
1
We thank an anonymous reviewer of the manuscript for suggesting this
alternative explanation.
(global probability) random sequences of two tones
[24]. Thus this alternative explanation suggests that
the MMN elicited by the global-rule deviant could be
the result of the unequal probabilities of the two
alternating tones in the micro-sequence preceding the
global-rule deviant.
2.2. Experiments 2 and 3
Experiments 2 and 3 were designed to test the four
alternative explanations. In Condition 1 of Experiment 2
(see Fig. 3, top row), random tones with varying frequencies were presented. If repeating a sound once already
establishes a representation of a repetition rule for this
sound then the stimulus change immediately following an
occasional tone repetition should elicit the MMN. In
contrast, if the stimulus change immediately following a
repetition does not elicit an MMN, then Alternative 1 can
be ruled out.
In Condition 2 of Experiment 2 (see Fig. 3, middle) a
sequence of tones whose frequencies alternated in an
abstract way were used. Neighbors of a tone were either
both lower or higher in frequency than the tone itself. The
sequence was like this: ‘ . . . Higher–Lower–Higher–
Lower–Higher–Lower . . . ’ The amount of frequencychange between consecutive tones was set to be random
with successive tones being easily distinguishable from
each other. This way, forming a global rule of the
alternation (i.e. to infer the frequency relationship between
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
temporally non-adjacent tones) was impossible, only the
abstract local rule could be encoded. This frequency
alternation regularity was then occasionally violated by
presenting two successive tones whose frequencies differed
from their predecessors in the same direction (i.e. ‘Higher–
Higher’ or ‘Lower–Lower’). If the abstract frequency
alternation rule was pre-attentively detected, such violations should elicit MMN. The tone following these deviants returned to the alternation rule (i.e. ‘Higher–Higher–Lower’ or ‘Lower–Lower–Higher’), therefore, it constituted a ‘standard’ following a local-rule only deviant. If
this return to alternation elicits the MMN then the ‘first
standard after a deviant’ explanation (Alternative 2) is
correct. Since this sequence cannot be described in terms
of global rules, the first standard following a deviant
situation is not confounded by global rule violation.
Therefore, if the ‘standard’ following a ‘deviant’ does not
elicit an MMN in this case then Alternative 2 can be ruled
out.
In Condition 3 of Experiment 2 (see Fig. 3, bottom row),
a simple alternation between the two tones was presented
using a random SOA. This procedure prevents the alternation-violation deviants from simultaneously violating the
SOA-regularity of the assumed separate high and low
sub-series because, with the random-SOA presentation, the
SOA in these sub-series also becomes variable. If occasional tone repetitions do not elicit an MMN in the
random-SOA sequence then one should conclude that the
constancy of SOA is an essential part of the representation
of simple tone alternation and that the auditory system
might have detected the alternation violations in Experiment 1 as violations of the SOA regularity in the high and
low sub-series (Alternative 3). In contrast, if MMN is
elicited by alternation violations even when the tones are
presented with a random SOA then the violation of SOAconstancy is not a necessary prerequisite of the detection
of alternation violations and, therefore, Alternative 3 can
be ruled out.
Finally, in Experiment 3 (see Fig. 4) random tones with
varying frequencies were presented (similarly as in Condition 1 of Experiment 2). Micro-sequences with an
‘AXAAB’ or ‘AAXAB’ pattern (A±X, A±B, and X±B)
were occasionally presented within the random stimulus
sequence. These patterns had three out of the four tones
preceding the B (probe) tone identical, but no three
137
identical tones in a row, just like it was before the
global-rule deviant in Experiment 1. If the probe tone
elicits an MMN in this situation, then Alternative 4 is
correct. In contrast, if these ‘3 out of 4 identical’ microsequences result in no MMN elicitation by the probe tone,
then Alternative 4 can be ruled out. It should be noted that
this situation is somewhat more favorable for MMN
elicitation by the probe than that was for the global-rule
deviant in Experiment 1 as, unlike the tones in the regular
alternation, the probe does not appear frequently within the
stimulus sequence (it is simply one of the random frequencies used to compose the sequence).
The alternation conditions of Experiment 2 realize
different generalizations of the simple tone-alternation
regularity. Therefore, alternation deviants in Experiment 2
also test whether these different generalized regularities are
detected and represented pre-attentively.
2.2.1. Subjects and procedure
Fourteen paid subjects with normal hearing (12 females,
16–22 years of age), none of whom participated in
Experiment 1, participated in Experiment 2. Due to
extensive artifacts (e.g. alpha-activity) resulting in the
rejection of a large number of trials, three subjects’ data
were discarded. Subjects were instructed to ignore the
sounds and read a self-selected book.
Eleven paid subjects with normal hearing (9 females,
18–23 years of age), none of whom participated in
Experiment 1 or 2, participated in Experiment 3. Subjects
were instructed to ignore the sounds and watch a selfselected subtitled movie without sound. One subject reported counting the stimuli despite the instruction to
disregard them; the data of this subject was excluded from
the analysis.
2.2.2. Stimuli
Stimuli were 100 ms long (including 5 ms rise and fall
times) pure sinusoid tones presented binaurally through
headphones at 70 dB (SPL). In Experiment 2 stimulus
blocks consisted of 1010 tones.
In Condition 1 of Experiment 2, sequences were equiprobably randomized from twenty tones differing only in
frequency (see Fig. 3, top row). Tone frequencies ranged
from 800.0 to 1278.9 Hz with proportionally equal, 2.5%
frequency steps. Consecutive tones of the sequences
Fig. 4. The stimulus sequence presented in Experiment 3. The sequences were equiprobably randomized from twenty tones differing only in frequency,
with infrequent five-tone long micro-sequences occurring randomly. The first four tones of the critical micro-sequences are of two kinds of tones differing
in their frequencies. One of the tones is presented three times (marked by gray shading) providing a relatively high local probability for this tone. The fifth
tone, called the probe, is marked by black color.
138
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
differed by at least two frequency-steps. SOA was 500 ms.
The two stimulus blocks of this condition contained 100
stimulus repetitions each. Stimulus repetitions were preceded by at least five stimulus changes.
In Condition 2 of Experiment 2, increase in frequency
was followed by a decrease in frequency and vice versa.
The stimulus sequences were randomized using forty
different tones covering, with equal 2.5% steps, the 625–
1678 Hz frequency range (see Fig. 3, middle row).
Frequency change between consecutive tones was equiprobably two, three, or four frequency steps. The SOA was
500 ms. In the four blocks of this condition, frequencychange alternation was violated fifty times each, (twentyfive times repeating frequency increase and twenty-five
times frequency decrease, the extent of frequency-change
being randomly two, three or four steps). Alternation
violations were preceded by at least five regular frequencychanges.
In Condition 3 of Experiment 2, two tones with 1000
and 1100 Hz frequencies were presented in an alternating
sequence (see Fig. 3, bottom row). The SOA was randomized with a uniform distribution in the 250–750 ms range.
In each of the four blocks of this condition, alternation was
violated fifty times by tone repetition (twenty-five times
‘AA’ and twenty-five times ‘BB’). Following the repetition, the sequence continued with a change. Repetitions
were preceded by at least five alternating tones.
In Experiment 3, stimulus blocks were constructed
similarly to those of Condition 1 of Experiment 2, except
that they consisted of 890 tones. Each of the eight stimulus
blocks in this experiment contained 44 micro-sequences, in
which a tone occurred exactly three times within four
consecutive stimuli. Half of these micro-sequences had the
pattern of ‘AXAA’, the other half ‘AAXA’, A and X
differing by at least two frequency steps. These microsequences were followed by a tone (the probe) that
differed both from the A and X tones by at least two
frequency steps. The critical micro-sequences were preceded by at least two random frequency changes.
2.2.3. EEG recording and data analysis
The parameters of EEG recording and data analysis
were identical to that in Experiment 1. In Condition 1 of
Experiment 2, responses to tone repetitions and the first
change following these repetitions were analyzed and
compared with the standard response (i.e., the response to
stimulus change with no deviant in the 5 preceding
positions of the sequence). In Condition 2 of Experiment 2,
the responses to repeated frequency increases and decreases (collapsed across deviants), and the response
elicited by the first regular sound change following these
deviants (the ‘standard after the deviant’) were compared
with the response to regular sound change following at
least five regular changes. In Condition three of Experiment 2, the response to tone repetitions (alternation
deviant) were compared with the standard response (i.e.,
the response to regular tone alternation with no tone
repetition within the preceding five positions). For control
purposes, we also compared the responses elicited by
standards separated from the previous identical tone by a
short SOA (i.e., the time between the two ‘A’s in
‘ . . . ABA . . . ’ ranging from 500 to 750 ms) with standards separated from the preceding identical tone by a
medium-duration SOA (ranging from 875 to 1125 ms).
Because the time between two consecutive identical standards was the sum of two random SOAs (both taken from
the 250–750 ms uniform distribution), 43.7% of the
standards belong to the medium-duration SOA range, and
12.5% of the standards belong to the short SOA range. If
deviants (repetition violations) elicit an MMN because of
their lower-than-average temporal separation from the
preceding identical tone (which was between 250 and 750
ms for deviants, as opposed to the regular 500 to 1500 ms
separation between two consecutive identical standard
tones) then the short-SOA standards could be expected to
elicit a similar MMN response. In Experiment 3 responses
to the probe tones (the ones following the critical microsequences) were compared with the standard response (i.e.,
the response to stimulus change separated by at least two
tones from the previous probe stimulus).
2.2.4. Results
Figs. 5–8 present the grand-average nose-referenced
frontal (Fz) ERP responses obtained in Experiments 2 and
3. Table 2 summarizes the results of Experiments 2 and 3.
Infrequent tone repetition embedded in the sequence
with continuously changing frequency (Condition 1 of
Experiment 2) elicited a frontally negative difference wave
(compared with the response to regular stimulus change;
Fig. 5, 1st row; see also Table 2). The change following
the repeated tone also elicited a frontally negative difference response (Fig. 5, 2nd row) peaking 109.465.6 ms
from stimulus onset with an amplitude of 20.6960.29 mV
(t(10)522.41, P,0.05). This negative difference was
identified as an increased N1 response due to its early peak
latency which corresponded to the similar N1 findings of
Experiment 1 (in which the increased N1 and the MMN
waves could be separately identified in the responses
recorded for changes following one or more tone repetitions; see Fig. 2, 3rd and 4th rows).
In Condition 2 of Experiment 2, the second consecutive
frequency increase or decrease elicited a frontally negative
difference response (compared with the ‘standard’ frequency-change alternation response). This response was
identified as an abstract frequency-alternation MMN (Fig.
6, 1st row, also see Table 2). No significant ERP difference was obtained between the ‘standard’ tone following
frequency-change alternation deviants and the regular
‘standard’ response (Fig. 6, 2nd row). Note that the
(statistically not significant) difference that can be seen at
about 170 ms on the left mastoid recording is in the
‘wrong’ (negative) direction for an MMN response.
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
139
Fig. 5. Frontal (Fz) grand-average ERP responses (nose-referenced) to standard and test tones (left column) and the corresponding test-minus-standard
difference curves at Fz and Lm (right column) in Condition 1 (random frequency change) of Experiment 2. Shading indicates the full (Lm-referenced)
MMN component. First row: tone repetition; 2nd row: change after repetition (the tone following a repeated tone).
In Condition 3 of Experiment 2, tone repetitions (Fig. 7,
1st row) elicited the MMN response (see Table 2). ShortSOA standards (see definition in EEG recording and data
analysis) did not elicit a significant differential response
compared with the medium-SOA standards (Fig. 7, 2nd
row). The slight (statistically not significant) difference
between 120 and 220 ms could not be an MMN, as its
polarity is opposite to that of the MMN component.
Fig. 6. Frontal (Fz) grand-average ERP responses (nose-referenced) to standard and test tones (left column) and the corresponding test-minus-standard
difference curves at Fz and Lm (right column) in Condition 2 (frequency-change alternation) of Experiment 2. Shading indicates the full (Lm-referenced)
MMN component. First row: alternation deviant (two consecutive frequency increases or decreases); 2nd row: standard following an alternation deviant (a
frequency decrease following two consecutive frequency increases or an increase following two decreases).
140
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
Fig. 7. Frontal (Fz) grand-average ERP responses (nose-referenced) to standard and test tones (left column) and the corresponding test-minus-standard
difference curves at Fz and Lm (right column) in Condition 3 (random-SOA tone alternation) of Experiment 2. Shading indicates the full (Lm-referenced)
MMN component. First row: alternation deviant (tone repetition); 2nd row: comparison between alternation standards separated from the preceding
identical tone by short (500–750 ms) vs. medium (875–1125 ms) intervals.
In Experiment 3, probes following the critical four-tone
micro-sequences in which three out four tones were the
same, did not elicit any observable difference compared
with the ‘regular’ frequency change response (Fig. 8).
Note that the frontal (Fz) negative differences identified
in the 100–300 ms post-stimulus interval were all accompanied by differential positive waves over the mastoid
leads. This suggests that N2b was not elicited by the
deviant and probe stimuli in Experiments 2 and 3.
2.2.5. Discussion
No MMN was elicited by a stimulus change following
an infrequent tone repetition within the sequence of
randomly varying tones (Condition 1 of Experiment 2).
This suggests that a single repetition is not sufficient for
setting up a repetition-regularity representation. Therefore,
the first alternative explanation of the MMN elicited by the
global-rule deviant in Experiment 1 (see the Discussion of
Experiment 1) can be ruled out. This result seems to be at
odds with those obtained by Winkler et al. [34], who
presented stimulus trains separated by 9.5 s intervals with
the tone frequencies changing from train to train. In this
study, MMN was obtained to tones presented in the third
position of those trains in which the third tone differed in
frequency from the common frequency of the first two
tones. Although this result indicated the possibility ‘that
the mismatch process can be elicited by a deviant stimulus
following only two presentations of the standard’, the
authors noted that ‘however, carryover of the transient
memory trace from the previous stimulus train did not
Fig. 8. Frontal (Fz) grand-average ERP responses (nose-referenced) to standard and probe tones (left column) and the corresponding probe-minus-standard
difference curves at Fz and Lm (right column) in Experiment 3. Probe tones followed four-tone long micro-sequences in which one tone occurred three
times without two consecutive repetitions.
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
141
Table 2
Summary of results from Experiments 2 and 3 a
Experiment and
condition
Stimulus-pattern
Peak latency
(ms)
Peak amplitude
(mV)
t
(df510)
Exp. 2, Cond.1
. . . ABCC . . . b
. . . ABCCD . . . b
. . . HLHH . . . c
. . . HLHHL . . . c
. . . ABAA . . .
Short-SOA standard d
. . . AXAAB . . . or . . . AAXAB . . . e
151.3 (8.3)
–
156.4 (5.4)
–
161.1 (4.9)
–
–
21.08 (0.25)
–
20.61 (0.24)
–
20.67 (0.30)
–
–
24.25**
–
22.50*
–
22.19*
–
–
Exp. 2, Cond.2
Exp. 2, Cond.3
Exp. 3
a
When MMN was elicited, the grand-average frontal (Fz, re-referenced to Lm) MMN peak latencies and mean amplitudes (standard errors of the mean in
parentheses) are given. In Conditions 1 and 2 of Experiment 2 and in Experiment 3, standards were regular tone changes following at least five regular
changes. In Condition 3 of Experiment 2, standards were regularly alternating tones following at least two cycles of undisturbed alternation; only the ones
separated by an SOA between 875 and 1125 ms were compared with the Short-SOA-standards. Both deviant and standard responses were collapsed across
the analogous patterns.
b
A±B, B±C, C±D.
c
H stands for a Higher, L stands for a Lower tone with respect to the tone immediately preceding it.
d
Two identical tones separated by an SOA between 500 and 750 ms.
e
A±X, A±B, B±X.
* P,0.05.
** P,0.001.
allow a definitive test of this issue’ (both sentences are
from Winkler et. al 1993, p. 411 [34]). Thus we can
conclude that the MMN obtained by Winkler et al. [34] in
the 3rd-position of their roving-frequency trains was
probably elicited with respect to the regularity set up by
the previous train (the carryover effect shown by Winkler
et al. [34]), whereas the formation of a new repetitive
regularity requires more repetitions of the same stimulus
(see below for further discussion).
Although tones following a repetition did not elicit an
MMN, the infrequent tone repetitions themselves elicited a
negative deflection whose characteristics were similar to
that of the MMN component. The infrequent tone repetitions appearing in a sequence whose regular feature is
stimulus (frequency) change violate this ‘change-regularity’. On this basis, the frontally negative ERP response
elicited by infrequent tone repetitions may be regarded as
an MMN component. Similar results have been obtained
¨
by Wolff and Schroger
[40]. In contrast, Ritter et al. [22]
found no MMN to infrequent (20% probability) tone
repetitions in a sequence randomized from five different
tones. The lack of a repetition-specific ERP response in
Ritter et al.’s study [22] might have resulted from the high
probability of repetition (20%), the low number of different frequencies used (as it has been shown that the auditory
system can probably maintain more than five frequently
recurring tones simultaneously; see Ref. [37]), and / or the
longer SOA in Ritter et al.’s design. An alternative
explanation of the differential ERP response elicited by
infrequent tone repetitions embedded in a sequence of
frequently changing tones would suggest that this component reflects a process for detecting constancy in an
ever-changing environment. It could be argued that there
are a number of regularities represented in the auditory
system for other acoustic features (e.g. SOA, intensity, and
tone duration are constant) but there is none for frequency.
The lack of any frequency-regularity representation may be
a distinct state of the pre-attentive auditory system that
makes it sensitive to regularities emerging in the frequency
dimension. In this case, the observed negative deflection
can be considered as a correlate of the emergence of a new
regularity representation when no regularity representation
was previously available. However, two arguments can be
put forward against this idea. First, the regularity representation emerges after a single tone repetition, then MMN
should have been elicited by a different tone following this
repetition. However, no MMN was elicited by the change
following this repetition. Second, according to the ‘new
regularity explanation’, a similar negative deflection
should be elicited by the second of two identical tones
presented after a long silent period. However, Cowan et al.
[5] found no such response when comparing trains starting
with two identical versus two different tones (trains were
preceded by 11–15 s of silence and tone frequencies
changed from train to train — the ‘roving-standard’
condition). Therefore, it seems more likely that ‘frequencychange’ can be pre-attentively represented as an abstract
feature-rule, with respect to which infrequent tone repetitions elicit the MMN. The lack of N2b elicitation by tone
repetitions supports the view that these instances were
pre-attentively detected as the attentive detection of tone
repetitions has been shown to elicit the N2b component
[22].
In Condition 2 of Experiment 2 the return to the local
alternation rule after an alternation violation did not elicit
MMN. No global alternation rule could be formed for this
sequence. Therefore, the second alternative explanation of
the MMN elicited by the global-rule deviant in Experiment
1 (see the Discussion of Experiment 1) can also be ruled
out (i.e. that this MMN is analogous to the MMNs
142
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
observed for standard stimuli following a deviant in simple
repetitive tonal sequences, see [24,19,36]). Importantly,
however, infrequent violations of this local-rule-only alternation (two consecutive frequency increases or decreases) elicited the MMN. This result demonstrated the
ability of the auditory system to pre-attentively represent
frequency-change-alternation, a generalized form of simple
frequency alternation.
In Condition 3 of Experiment 2, infrequent tone repetitions elicited the MMN in a simple alternating sequence
presented with random SOA, whereas ‘standard’ (regularly
alternating) tones presented with a short SOA did not. This
result rules out the alternative explanation suggesting that
infrequent repetitions and subsequent structural violations
in an alternating sequence of two tones elicit MMN
because they violate the regular temporal separation between consecutive identical tones (see Discussion of
Experiment 1). Results of this condition demonstrate that
the MMNs elicited by infrequent structural violations in a
sequence of two regularly alternating tones at least partly
reflect deviation from a genuine structural representation of
these sequences. The present results provide a further
important implication: the constancy of SOA is not a
necessary pre-requisite for the pre-attentive detection of
alternation. This means that also this generalization of
alternation can be represented even in the absence of
focused attention. However, previous studies demonstrated
that the temporal aspects of the stimulation are intimately
linked with the perceived structure of auditory stimulus
sequences. By changing the timing of stimulus delivery
one can modify the perception of sound sequences. For
example, speeding up the presentation rate of the present
sequence of alternating tones would make the low and high
tones form separate streams; see Ref. [4]. A number of
recent studies suggest that the temporal and structural
features of sound sequences are processed, and probably
also encoded, together during pre-attentive auditory processing [2,3,32] as well as that the schedule of stimulus
delivery can determine the elicitation of the MMN component by violations of sequential (structural) regularities
[29,30,39]. The present results do not contradict the notion
of integration between the temporal and structural features
of sound sequences. In fact, the lack of MMN in the
Short-SOA-standard responses in Condition 3 showed that
temporal and structural regularities of a given sequence
refer to the same organization of this sequence. (MMN
elicitation by Short-SOA alternation standards would have
suggested that the segregated [separate low and high
sequences] organization of the sequence was maintained
simultaneously with the integrated [low–high alternation]
organization.)
In Experiment 3, the probe tones did not elicit an
observable MMN. These probes followed micro-sequences
that modeled the ratio between the two tones in the
micro-sequence immediately preceding the global-rule
deviant in Experiment 1. This result rules out the alternative explanation, which suggests that the MMN elicited
by the global-rule deviant resulted from unequal local
stimulus probabilities (see Discussion of Experiment 1).
3. General discussion
The aim of the present study was to determine (a)
whether global rules (i.e., relations between temporally
non-adjacent stimuli) can be represented pre-attentively
and (b) whether different types of rules describing the
same sound sequence are maintained simultaneously in the
absence of focused attention.
The present results showed that global-rule representations of auditory stimulus sequences could be formed
pre-attentively. This suggests that the auditory system is
able to associate non-adjacent sounds within the larger
structure of a sequence, even when one’s attention is
directed away from the sounds.
The second main conclusion from the present results is
that at least two different rules can be pre-attentively
abstracted from a simple alternating tone sequence. Furthermore, incoming sounds were checked against the
representation(s) of both of these rules. Previous studies
have shown that rules for the frequent return of two
(possibly even more) sounds can be maintained at the same
time (e.g., Ref. [38]). It is also true that rules describing
the repetition of a stimulus event include all featurerepetition rules as well as the repetition of feature conjunctions, as deviations in different auditory features and / or
conjunction of features elicit separate MMNs within the
same sequence (e.g. Refs. [6,9,26,31]). Feature-repetition
rules can also coexist with more complex structural rules
of the sequence. Winkler & Czigler [35] presented a
sequence of two regularly alternating tones that differed
only in frequency. Infrequent tones having the frequency
of the tone preceding them and a duration which was
shorter than the common duration of the two ‘standard’
tones elicited two successive MMNs (one to the break of
frequency alternation and another to duration deviance)
demonstrating that both alternation and the constancy of
duration were simultaneously represented during pre-attentive auditory processing. Corroborating evidence was
obtained for alternation between the two ears and frequency-intensity conjunctions by [32]. From these and the
present results it is clear that a large number of rules
(feature and event rules, local and global rules) are
simultaneously detected and represented during the preattentive analysis of the auditory environment. The present
results further suggest that concrete and abstract rules of
the same sequence are maintained in parallel. Violations of
a regular frequency-change alternation (the abstract variant
of frequency alternation) elicited the MMN (see Fig. 6). As
the regular alternation of two tones differing only in
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
frequency is a special case of this general class of
alternations, it is possible that the general rule is also
established for simple alternations.
Furthermore, the present results are compatible with the
notion that redundant structural rules describing the same
sound sequence are encoded together. In Experiment 1, the
sum of the responses to local- and global-rule deviants
significantly differed from the response to the both-rules
deviant. This indicates that the responses are not additive.
In fact, the MMN amplitudes elicited by these three
different deviants did not significantly differ from each
other. However, it must be noted that the present paradigm
was not optimal for testing the additivity of the local- and
global-rule MMNs, as the both-rules deviant followed a
somewhat different sequence than either the local or the
global-rule deviant. Additionally, the scalp distributions of
the MMNs were similar, which suggests that these responses are generated by at least partially overlapping
neuronal populations.
The present conclusions suggesting simultaneous representations of multiple redundant regularities for the same
stimulus sequence are fully compatible with Bregman’s [4]
assumption of the existence of several pre-attentive processes that analyze the auditory input in parallel. These
processes provide the basis for the organization of the
acoustic environment. The present results also strongly
support the hypothesis that the auditory system maintains a
complex neural model of the acoustic environment even in
the absence of focused attention [36]. As the auditory
environment continuously changes, the regularities extracted from it require constant monitoring, lest they
become outdated. Deviant auditory events thus serve a
double role: (1) they carry new, potentially important
information (i.e., information that could not be extrapolated from the preceding sequence) and, therefore, may
require further evaluation; (2) they mark changes in the
regularities of the auditory environment (i.e., instances
when new rules may supersede some previously detected
rules) and, therefore, initiate modifications in the representation of rules. The MMN-generating process is probably involved in both of these functions [11,34,36]. The
present results provided a demonstration of the adaptability
of this system (cf. [36,16]). Two successive repetitions
breaking the alternation (three consecutive presentations of
the same tone) established a repetition-rule representation,
as was shown in Experiment 1 (see Fig. 2). However, a
single repetition embedded in a sequence of tones with
randomly changing frequencies was not sufficient for
creating a new repetition rule representation (see Fig. 4).
Comparable results have been obtained in previous studies
[5,27,36]. These results demonstrate that the auditory
system quickly adapts to changes in the regularities of the
acoustic environment but rejects chance occurrences. A
minimal prerequisite of three events for the activation of a
new rule representation is probably an optimum between
143
the need for fast adaptation and for efficiency (i.e., creating
short-living, possibly false, rule representations would tax
the available resources and reduce the utility of the model).
Acknowledgements
This research was supported by the Hungarian National
Research Fund (OTKA T022800) and the National Institutes of Health Grant (R55 DC04263).
References
[1] C. Alain, D.L. Woods, K.H. Ogawa, Brain indices of automatic
pattern processing, NeuroReport 6 (1994) 140–144.
[2] C. Alain, A. Achim, D.L. Woods, Separate memory-related processing for auditory frequency and patterns, Psychophysiology 36
(1999) 737–744.
[3] C. Alain, F. Cortese, T.W. Picton, Event-related brain activity
associated with auditory pattern processing, NeuroReport 10 (1999)
2429–2434.
[4] A.S. Bregman, Auditory Scene Analysis, MIT Press, Cambridge
MA, 1990.
¨¨ ¨
[5] N. Cowan, I. Winkler, W. Teder, R. Naatanen,
Memory prerequisites
of mismatch negativity in the auditory event related potentials
(ERP), J. Exp. Psychol. Learn. Mem. Cogn. 19 (1993) 909–921.
[6] D. Deacon, J.M. Nousak, M. Pilotti, W. Ritter, C.M. Yang, Automatic change detection: douse the auditory system use representations of individual stimulus features or gestalts? Psychophysiology
35 (1998) 413–419.
[7] J.M. Ford, S.A. Hillyard, Event-related potentials (ERPs) to interruptions of a steady rhythm, Psychophysiology 18 (1981) 322–330.
[8] H. Gomes, R. Bernstein, W. Ritter, H.G. Vaughan Jr., J. Miller,
Storage of feature conjunctions in transient auditory memory,
Psychophysiology 34 (1997) 712–716.
¨
[9] S. Levanen,
R. Hari, L. McEvoy, M. Sams, Responses of the human
auditory cortex to changes in one vs. two stimulus features, Exp.
Brain Res. 97 (1993) 177–183.
[10] G. McCarthy, C.C. Wood, Scalp distributions of event-related
potentials: An ambiguity associated with analysis of variance
models, Elecroencephalogr. Clin. Neurophysiol. 62 (1985) 203–208.
¨¨ ¨
[11] R. Naatanen,
Selective attention and stimulus processing: Reflections in event related potentials, magnetoencephalogram and regional cerebral blood flow, in: M.I. Posner, O.S.M. Marin (Eds.),
Attention and Performance XI, Lawrence Erlbaum, Hillsdale, NJ,
1985, pp. 355–373.
¨¨ ¨
[12] R. Naatanen,
The role of attention in auditory information processing as revealed by event-related potentials and other brain measures
of cognitive functions, Behav. Brain Sci. 13 (1990) 201–288.
¨¨ ¨
[13] R. Naatanen,
Attention and Brain Function, Lawrence Erlbaum,
Hillsdale NJ, 1992.
¨¨ ¨
¨
[14] R. Naatanen,
A.W. Gaillard, S. Mantysalo,
Early selective attention
effect on evoked potential reinterpreted, Acta Psychol. 42 (1978)
313–329.
¨¨ ¨
[15] R. Naatanen,
T.W. Picton, The N1 wave of human electric and
magnetic response to sound: a review and an analysis of the
component structure, Psychophysiology 24 (1987) 375–425.
¨¨ ¨
[16] R. Naatanen,
I. Winkler, The concept of auditory stimulus representation in cognitive neuroscience, Psychol. Bull. 125 (1999) 826–
859.
[17] H. Nordby, W.T. Roth, A. Pfefferbaum, Event-related potentials to
144
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
´ et al. / Cognitive Brain Research 12 (2001) 131 – 144
J. Horvath
time-deviant and pitch-deviant tones, Psychophysiology 25 (1988)
249–261.
H. Nordby, W.T. Roth, A. Pfefferbaum, Event-related potentials to
breaks in sequences of alternating pitches or interstimulus intervals,
Psychophysiology 25 (1988) 262–268.
J.M.K. Nousak, D. Deacon, W. Ritter, H.G. Vaughan Jr., Storage of
information in transient auditory memory, Cogn. Brain Res. 4
(1996) 305–317.
T.W. Picton, S. Bentin, P. Berg, E. Donchin, S.A. Hillyard, R.
Johnson Jr., G.A. Miller, W. Ritter, D.S. Ruchkin, M.D. Rugg, M.J.
Taylor, Guidelines for using event-related potentials to study
cognition: recording standards and publication criteria, Psychophysiology 37 (2000) 127–152.
W. Ritter, D. Deacon, H. Gomes, D.C. Javitt, H.G. Vaughan Jr., The
Mismatch negativity of event-related potentials as a probe of
transient auditory memory: a review, Ear Hear. 16 (1995) 52–67.
W. Ritter, P. Paavilainen, J. Lavikainen, K. Reinikainen, K. Alho, M.
¨¨ ¨
Sams, R. Naatanen,
Event-related potentials to repetition and change
of auditory stimuli, Elecroencephalogr. Clin. Neurophysiol. 83
(1992) 306–321.
¨
J. Saarinen, P. Paavilainen, E. Schroger,
M. Tervaniemi, R.
¨¨ ¨
Naatanen,
Representation of abstract attributes of auditory stimuli in
the human brain, NeuroReport 3 (1992) 1149–1151.
¨¨ ¨
M. Sams, K. Alho, R. Naatanen,
Sequential effects in the ERP in
discriminating two stimuli, Biol. Psychol. 17 (1983) 41–58.
¨
E. Schroger,
An event-related potential study of sensory representations of unfamiliar tonal patterns, Psychophysiology 31 (1994)
175–181.
¨
E. Schroger,
Processing of auditory deviants with changes in one
versus two stimulus dimensions, Psychophysiology 32 (1995) 55–
65.
¨
E. Schroger,
On the detection of auditory deviants: a preattentive
activation model, Psychophysiology 34 (1997) 245–257.
¨
E. Schroger,
Measurement and interpretation of the mismatch
negativity, Behav. Res. Methods Instrum. Comput. 30 (1998) 131–
145.
E. Sussman, W. Ritter, H.G. Vaughan Jr., An investigation of the
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
[38]
[39]
[40]
auditory streaming effect using event related brain potentials,
Psychophysiology 36 (1999) 22–34.
¨¨ ¨
E. Sussman, I. Winkler, W. Ritter, K. Alho, R. Naatanen,
Temporal
integration of auditory stimulus deviance as reflected by the
mismatch negativity, Neurosci. Lett. 264 (1999) 161–164.
¨¨ ¨
R. Takegata, P. Paavilainen, R. Naatanen,
I. Winkler, Independent
processing of changes in auditory single features and feature
conjunctions in humans as indexed by the mismatch negativity,
Neurosci. Lett. 266 (1999) 109–112.
¨¨ ¨
R. Takegata, P. Paavilainen, R. Naatanen,
I. Winkler, Pre-attentive
processing of simple and complex acoustic regularities: a mismatch
negativity additivity study, Psychophysiology 38 (2001) 92–98.
¨¨ ¨
M. Tervaniemi, S. Maury, R. Naatanen,
Neural representations of
abstract stimulus features in the human brain as reflected by the
mismatch negativity, NeuroReport 5 (1994) 844–846.
´
¨¨ ¨
I. Winkler, N. Cowan, V. Csepe,
I. Czigler, R. Naatanen,
Interactions
between transient and long-term auditory memory as reflected by the
mismatch negativity, J. Cogn. Neurosci. 8:5 (1996) 403–415.
I. Winkler, I. Czigler, Mismatch negativity: deviance detection or the
maintenance of the ‘standard’, NeuroReport 9 (1998) 3809–3813.
¨¨ ¨
I. Winkler, G. Karmos, R. Naatanen,
Adaptive modeling of the
unattended acoustic environment reflected in the mismatch negativity event-related potential, Brain Res. 742 (1996) 239–253.
I. Winkler, P. Paavilainen, K. Alho, K. Reinikainen, M. Sams, R.
¨¨ ¨
Naatanen,
The effect of small variation of the frequent auditory
stimulus on the event-related brain potential to infrequent stimulus,
Psychophysiology 27 (1990) 228–235.
¨¨ ¨
I. Winkler, P. Paavilainen, R. Naatanen,
Can echoic memory store
two traces simultaneously? A study of event-related brain potentials,
Psychophysiology 29 (1992) 337–349.
¨
I. Winkler, E. Schroger,
N. Cowan, The role of large-scale perceptual organization in the mismatch negativity event-related brain
potential, J. Cogn. Neurosci. 13 (2001) 59–71.
¨
Ch. Wolff, E. Schroger,
Activation of the pre-attentive change
detection system by tone repetitions with fast stimulation rate, Cogn.
Brian Res. 10 (2001) 323–327.