The Effect of Auditory Stimulus Duration on the P300 Response Effet

The Effect of Auditory Stimulus Duration on the P300 Response Effet
The Effect of Auditory Stimulus Duration on the P300 Response
Effet de la duree du stimulus sonore sur la reponse P300
Patrick J. O'Brien ami Alldrew Stuart
Department of Commullication Sciellces and Disorders
East Carolina University
Greenville, North Carolina
Abstract
An examination of the effect of stimulus duration on the auditory P300 response was undertaken. Twelve young normal·hearing adults served as
participants. P300 responses were obtained with an "odd ball" stimulus paradigm. The frequency of stimuli were 1000 Hz tones of 75 ms duration
with a 5 ms rise/fall time. The rare stimuli were either 50 ms or 25 ms 1,000 Hz tones with 5 ms rise/fall times. Stimuli were presented at 70 dB pSPL
and 30 dB pSPL. All participants exhibited a response in the easiest discrimination condition (i.e., 75 ms frequent and 25 ms rare tonal stimuli
presentation at 70 pSPL). When the stimuli intensity decreased and the duration of the rare tone increased, P300 responses were not observed with
all participants. Shorter P300 latencies and greater response amplitudes were found at the higher stimulus intensities and when the duration
difference between the frequent and rare tone was the greatest. The findings of this study suggest that auditory stimulus duration may serve as the
sole discriminatory factor to evoke the P300 response.
Abrege
Cette recherche effectuee aupres de douze jeunes adultes a I'ou'ie norma le a analyse I'effet de la duree du stimulus sur la reponse auditive P300. Les
reponses ont ete obtenues avec un paradigme de stimulus irregulier. Les frequences des stimuli etaient des tons de 1000 Hz d'une duree de 75 ms
avec un temps de montee et de descente de 5 ms. Les stimuli rares representaient des tons de 1000 Hz d'une duree de 50 ms ou de 25 ms avec un
temps de montee et de descente de 5 ms. Les stimuli etaient presentes a 70 dB pSPL et a 30 dB pSPL. Tous les participants ont reagi a la condition
de discrimination la plus simple (stimulus tonal frequent de 75 ms et rare de 25 ms a un niveau de 70 pSPL). Lorsque I'intensite des stimuli diminuait
et que la duree du ton rare augmentait, les participants n'ont pas tous eu de reponses P300. Des latences P300 plus courtes et des amplitudes de
reponse plus grandes ont ete observees dans les cas d'intensites de stimulus plus hautes et lorsque la difference de duree entre le ton frequent et
le ton rare etait la plus elevee. Les conclusions de cette etude laissent entendre que la duree du stimulus sonore pourrait representer le seul facteur
de discrimination permettant de susciter une reponse P300.
Key words: P300, auditory stimulus duration, auditory system, hearing evaluation, electrophysiology
acoustically evoked P300 typicalJy requires listeners
to consciously discriminate a rare target stimulus (i.e.,
n oddball with a low probability during pseudo-random presentation) embedded in a train of frelluent stimuli
(Hall, 1992; ~IcPherson, 1996). The task generally involves
two tones that vary in frequency or intensity but may also
employ speech stimuli that differ along a temporal or spectral
dimension. The P300 is an endogenous response believed to
reflect cognitive processes invoked by psychological operations independent of the stimulus characteristics (Hillyard &
Picton, 1979).
A
subject of numerous investigations. The effect of stimulus
frequency (Cass & Polich, 1997; Sugg & Polich, 1995; Vesco,
Bone, Ryan, & Polich, 1993) and intensity differences (Adler
& Adler, 1991; Cass & Polich, 1997; Covington & Polich,
19%; Johnson & Donchin, 1978; Papanicolaou, Loring, Raz,
& Eisenberg, 1985; Polich, ElJerson, Cohen, 1996; Roth, Doyle,
Pfefferbaum, & KopelJ, 1980; Sugg & Polich; \Xial ton, CaUaway,
Halliday, & Naylor, 1987; Vesco et aI., 1993) between rare and
frequent tones have been explored. In general, more identifiable differences between rare and frequent stimuli yield shorter
latencies and greater amplitudes with the P300 response.
The issue of how "perceptually different" the rare stimuli
has to be in order to evoke the P300 response has been the
How variations in auditory stimulus duration affect the
P300 response, however, have not been explored in depth. To
JOURNAL OF SPEECH-LANGUAGE PATHOLOGY AND AUDIOLOGY, VOL. 25, NO. 1, SPRING 2001
Effect of Stimulus Duration on the P300
the best of our knowledge only two studies have explored
changes in stimulus duration and the effect on the P300. Polich
(1989) manipulated rare tone (2,000 Hz) and frequent tone
Cl ,000 I-lz) intensity (i.e., 30, 50, and 70 dB SPL) and duration
(i.e., 20, 50, and 80 ms) in a factorial design. The rare and
frequent tones were presented at the same intensity. Polich
reported that P300 latency decreased significantly (p < .(5)
with increases in stimulus intensity and duration (p < .0(1).
There was no effect of either stimulus intensity or duration
on the amplitude of the P300 response (p < .05). In other
words, the more identifiable differences between rare and frequent stimuli yield shorter latencies and greater amplitudes.
Similarly, Obert and Cranford (1990) reported a significant
change in P300 latency and amplitude with a discrimination
task where stimulus fre<-Iuency and duration varied. In their
"easy" task, the stimulus duration was 20 ms while the frequency of the rare and fre'-juent tones was 20()0 and 750 Hz,
respectively. Stimulus duration was five ms while the frequency
of the rare and fre'-juent tones was 1,000 and 750 Hz, respectively in their "hard" task. \X/ith their normal-hearing listeners, P300 latency was significantly decreased with a
concomitant significant increase in amplitude in the easy discrimination task. Two of 10 participants with neocortical lesions failed to demonstrate a P300 response during the testing,
while the remaining eight participants demonstrated absent or
delayed P300 responses during 53'y(, of test runs.
The effect of duration differences between the rare and
fre'-juent stimuli as the sole discriminatory factor with the P300
response is unavailable. Toward that cnd, the purpose of this
study was to examine the effect of stimulus duration on P300
latency and amplitude among normal-hearing young adults.
als had a negative history of neurological, otological, and psychiatric disorders.
Appa ra t1Is
A double wall sound-treated audiometric suite (Industrial Acoustics Corporation), meeting specifications for permissible ambient noise (American National Standards Institute,
1999), served as the test environment. Participants were tested
with a Nicolet Spirit evoked potential system.
Tonal stimuli generated by the evoked potential system
were applied to an insert earphone (Nicolet model TIP-3()())
at a rate of 1.1 / s with alternating polarity. The frequent stimuli
were 1,000 Hz tones of 75 ms duration with a five ms rise /
fall time. The rare stimuli were eitha 50 111S or 25 ms 1,000
Hz tones with five ms rise/ fall times. All stimuli were linearly
gated. Stimuli were presented at 70 dB pSPL and 30 dB pSPL.
These stimuli were chosen based on pilot data that suggested
that the stimuli were easily discriminable for young adult normal-hearing listeners.
Procedures
P300 responses were obtained with an "oddball" stimulus paradigm (Squires & Hecox, 1983). Fre'-juent and rare
stimuli were presented with SO% and 20(Y.l probabilities, respectively. The four test conditions (i.e., 75 ms fre'-juent and
50 m5 rare tonal stimuli at 70 dB pSPL; 75 ms freLjuent and
25 ms rare tonal stimuli at 70 dB pSPL; 75 ms fre'-juent and
50 ms rare tonal stimuli at 3() dB pSPL; and, 75 ms frequent
and 25 ms rare tonal stimuli at 30 dB pSPL) were counterbalanced across participants. Stimuli were presented to the right
ear of all participants.
,\n examination of such could lead to the application of the
P300 auditory evoked response to investigate
electrophysiological correlates of perceptual processing of
duration <.liscrimination with normal -hearing listener's and lis-
Table 1. Numbers Of Participants Exhibiting a P300
Response as a Function of Stimulus Intensity Level (dB
pSPL), Frequent and Rare Stimuli Duration, and
Gender.
tener's with auditory pathology.
Gender
Method
Male
Participants
Twelve young adults served as partiCipants (M = 25.8
0.9; six males and six females). j\ll participants
years, SF
presented with normal middle car function as assessed with
immittance audiometry (American Speech-Lanf.,ruage-Hearing
Association, 1990) and norl11al hearing sensitivity defined as
having pure-tone thresholds at octave frequencies from 250
to SOOO Hz and speech recognition thresholds of <; 20 dB HL
(American National Standards Institute, 1996). All individu-
Intensity
=
20
~
Female
I
Stimuli Duration
(Frequent/Rare)
-
-
75/25 ms
70 dB P SPL
6
75/50 ms
5
75/25 ms
70 dB P SPL
--- --.--.
30 dB P SPL
75/50 ms
30 dB P SPL
4
LA REVUE D'ORTHOPHONIE ET D'AUDIOLOGIE, VOL. 25. NO. 1, PRINTEMPS 2001
5
6
--6
5
._3
Effect of Stimulus Duration on the P300
Silver-chloride cup electrodes conslstlng of one
(noninverting) attached to the vertex (Cz), onc (inverting)
attached to the right mastoid (M2), and onc (common) attachecl to the forehead (Fz) were employed. Interelectrode
Table 2. Means and Standard Deviations Of The P300
Latencies And Amplitudes as a Function of Stimulus
IntenSity Level, Frequent and Rare Stimuli Duration,
'\
and Gender.
Gender
impedances were maintained below 5,000 Q. The recorded
electroencephalogram was ampli fied 50,000 times and analogue bandpass filtered (1
to
30 Hz, Butterworth filter with
a roll-off slope of 12 dB/octave). Electroencephalogram
samples exceeding
±
50 ~V were rejected automatically.
An analysis time of 750 ms post-stimulus onset was sampled at 667 Hz. A total of 300 (i.e., 240 frequent and 60
Participants were tested while sitting comfortably. They
Stimuli Duration
Intensity
75/25 m s
70dBpSPL
328.8
(30.2)
342.0
(26.90)
75/50 ms
70dBpSPL
438.2
(24.3)
429.3
(264)
75/25 ms
30dBpSPL
363.3
(40.7)
3684
(26.8)
75150 ms
30 dB pSPL
419.5
(40.8 )
423.0
(27.2)
were instructed to count the number of presentations of
the rare stimuli during each trial. During the " easy" 75 ms
frequent and 25 ms rare tonal stimuli presentation trials,
participants displayed 9m,'( ) (.ID
= 2.5)
accuracy in total
counts of the rare stimuli. Participants displayed an accu racy of 88°;') (SD
= 4.6)
in reporting total coun ts of the
rare stimuli during the "difficult" 75 ms frequent and 50
Amplitude (JlV)
Stimuli Duration
Intensity
75/25 ms
70dBpSPL
14.3
(3.8)
13.2
(3 .5 )
75/50 ms
70 dB pSPL
8.8
(4.2)
8.6
(1.6 )
75/25 m s
30dBpSPL
8.7
(3.1 )
12.6
(3.8 )
75/50 ms
30 dB pSPL
64
(4.2)
6.6
(2.3)
ms rare tonal stimuli.
Presence of the P300 response required the agree-
Female
Latency (Jls)
rare tones) samples were averaged simultaneously, but separately, and replicated for all trials.
Male
ment of three audiologists experienced in P300 testing. All
observers, who were blind to test condition, inspected the
waveforms joint! y. The P300 response was defined as the
largest positive going peak occurring between 250 and 500
ms. Replication was defined as two or more waveforms
with identifiable P300 peaks within 25 ms. P300 latency
was definecl as the time point of maximum positive amplitude. P.300 amplitude was measured from the P300 peak to
the most negative following troug h before positive deflection.
Results
Numbers of participants exhibiting a P300 response as a
function of stimulus intensity level, freljuent and rare stimuli
duration, and gender arc presented in Table 1. As evident in
the table, all participants exhibited a response in the easiest
discrimination condition (i.e., 75 ms frelluent and 25 ms rare
tonal stimuli presentation at 70 pSPL). When the stimuli intensity decreased and the duration of the rare tone increased
P300 responscs \vere not observed with all participants. Mcans
and standard deviations of the P300 latencies and amplitudes
as a function of level of stimulus intensity, freljuent and rare
stimuli duration, and gender arc presented in Table 2.
as a function of stimulus intensity, duration, and gender due
to missing data. It was believed that thc missing data wcre not
indepcndent of the experimental treatment conditions (i.e.,
not random). endcr such circumstances violations to analysis
of variance are assumed (Keppel & I.cdeck, 1(89). What fol lows is a global assessment of the data set. In general, data for
both genders were similar. \X'aveforms from rhe participants
that evoked P300 responses were used to construct grand averages. These waveforms for the four test conditions are displayed in Figure 1. As evident in Table 2 and in Figure I,
shorter latencies and greater response amplitudes were found
at the higher stimulus intensities and whcn thc duration difference between the frecluent and rare tone was the greatest
(i.e., 75 ms vs. 25 ms).
Conclusions and Discussion
Inferential statistical analyses were not undertaken to in-
The findings of this study suggcst that auditory stimulus
duration may serve as the sole discriminatory factor to evoke
vcstigate mean differences in P300 latencies and amplitudes
the P300 response. It must be noted that when the discrimi-
JOURNAL OF SPEECH·LANGUAGE PATHOLOGY AND AUDIOLOGY. VOL. 25 . NO. 1, SPRING 2001
Effect of Stimulus Duration on the P300
Figure 1. Grand average P300 responses as a function of
presentation level and duration of frequent/rare tones.
70 dB SPL
75/25 ms
not found when the duration difference between the rare
and frequent tones was 25 ms. The application of the
P300 auditory evoked response to investigate
elcctrophysiological correlates of perceptual processing
of duration discrimination among patients with temporal
resolution difficulties may be profitable.
Author Notes
75/50 ms
30 dB SPL
75/25 ms
75/50 ms
Portions of this paper were presented in part at the
American Academy of Audiology Twelfth Annual Convention, Chicago, IL, l'vfarch 17, 2000.
Patrick O'Brien is currently affiliated with Otolaryngology and Cosmetic Surgery Institute of South Florida,
Lauderdale Lakes, FL Please address all correspondence
to Andrew Stuart, PhD, Department of Communication
Sciences and Disorders, East Carolina University,
Greenville,
North
Carolina,
27858-4353;
s [email protected]
References
2.49~V~
75.0 ms
Adler, G., & Adler, 1. (1991). Auditory stimulus processing at
diffcrcnt stimulus intensities as reflected by auditory evoked potentials. Biological P.lychiatry, 29, 347-356.
American National Standards Institute. (1996). !:'pecijications
/01' audiometers. (ANSI S3.6-1996). New York: ANSI.
nation task became more difficult, P300 responses were not
evident in all listeners. For those participants who displayed
P300 responses, response latency increased and response amplitude decreased as the duration of the rare and frequent
tones became more similar ancl stimulus intensity decreased.
These findings arc consistent with previous research that has
demonstrated that the P300 response is more identifiable when
fre'juent and rare tone differences are more salient (Cass &
Polich, 1997; Obert & Cranford, 1990; Polich, 1989; Sugg &
Polich, 1995; Vesco et aI., 1(93) and when evoking stimuLi are
presented at higher stimulus intensities (Adler & Adler, 1991;
Cass & Polich; Covington & Polich, 1996;Johnson & Donchin,
1978; Papanicolaou et aI., 1985; Polich et aI., 1996; Roth et aI.,
1980; Sugg & Polich; Walton et aI., 1987; Vesco et al.). It is
likdy that the changes in the P300 response "most likely stem
from stimulus evaluation processes" (polich, 1989, p. 285).
The implementation of this task as a clinical tool needs
to be further explored. These findings suggest that a duration
discrimination P300 paradigm should only be used if the difference between the rare and frecluent tone is at least 50 ms.
Evidence of all listeners demonstrating P3()() response was
22
American National Standards Institute. (1999). Permissihle all/hient lIoise levels PII' audiometric test roOIl/S. (ANSI S3.1-1999).
New York: ANSI.
American-Speech-Language-Hearing Association. (1990). Guidelines for screening for hearing impaillnents and middle car disorders.
Asha, 32 (Suppl. 2), 17-24.
Cass, M., & Polich, 1. (1997). P300 from a single-stimulus paradigm: auditory intensity and tone frequency effects. Biological Psychiatl:V, 46. 51-65.
Covington,1. w., & Polich, 1. (1996). P300, stimulus intensity, and
modality. Electroencephalography and Clinical Neurophysiology, I aa,
579-584.
Hall, 1. W., Ill. (1992). Hamlhook of auditOfY evoked potentia!.\·.
Needham Heights, MA: Allyan and Bacon.
Hillyard, S. A., & Picton, T. W. (1979). Event-rclated brain potentials and selective information processing. In J. E. Dcsmedt (Ed.), Cognitive components in cerehral event-related potentials and selective
allention (pp. I-52). Base!, Switzerland: Karger.
Johnson, R. Jr., & Donchin, E. (1978). On how P300 amplitude
varies with the utility of the eliciting stimuli. Electroencephalography
al/d Clinical Neurophysiology, 44, 424-437.
Keppel, G., & Zedeck, S. (1989). Data ana~vsis .Iil/, research design. New York: W. H. Freeman and Company.
McPherson, D. L. (1996). Late potentials o/the al/ditDlY system.
San Diego, CA: Singular.
Obert, A. D, & Cranford, J. L (1990). Effects of neocortical lesions
on the P300 component of the auditory evoked response. American Journal o/Otolology, 11, 447-453.
LA REVUE O'ORTHOPHONIE ET O'AUOIOLOGIE, VOL. 25, NO. 1, PRINTEMPS 2001
Effect of Stimulus Duration on the P300
Papanicolaou, A. c., Loring, D. w., Raz, N., & Eisenberg, H. M.
(1985). Relationship between stimulus intensity and the P300. Psychophysiology, 22. 326-329.
Squires, K. c., & Heeox, K. E. (1983). Eleetrophysiological evaluation of higher level auditory processing. Seminars ill Hearing. 4, 415433.
Polich, l. (1989). Frequency, intensity, and duration as determinants of P300 from auditory stimuli. Joumal of Clinical NeulVphysiolog)', 6, 277-286.
Sugg, M. l., & Polich, J. (1995). P300 from auditory stimuli: Intensity and frequency effects. Biological Psych 010,£,,)', 41, 255-269.
Polich, l., Ellerson, P. c., & Cohen l. (1996). P300, stimulus intensity, modality, and probability. Intemational Journal of Psychophysiology, 23, 55-62.
Roth, W. T., Doyle, C. M., Pfefferbaum, A., & Kopell, B. S. (1980).
Effects of stimulus intensity on P300. PlVgress in Brain Research, 54,
296-300.
Vesco, K. K., Bone, R. C., Ryan, l. C, & Polich, l. (1993). P300 in
young and elderly subjects: auditory frequency and intensity effects.
£Iectroel/cephalograp/ty and Clinical Ne 11 rop hys iolol",)" 88, 302-308.
Walton, P., Callaway, E" Halliday, R .. & Naylor. H. (1987). Stimulus intensity, contrast, and complexity have additive effects on P300
latency. £Iectroellcephalography and Clil/ical Neurophysiology SupplelIIent, 40, 284-292.
Mallllscript receilJe(/: Marc/, " 2000
.Accepted: i\'ovell/ber 15, 2000
JOURNAL OF SPEECH-LANGUAGE PATHOLOGY AND AUDIOLOGY, VOL. 25. NO. 1, SPRING 2001
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement