The video-recorded stroop color-word test as a new model of experimentally-induced anxiety

Prog Nemo-PsychophmamL

BaBid

1999, Vol. 23, pp. 809422

Psychiaf Copyright Printed

0 1999 Elsetier

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front matter

1

THE VIDEO-RECORDED STROOP COLOR-WORD NEW MODEL OF EXPERIMENTALLY-INDUCED JOSE ROBERTO LEITE’ VANIA A. SARTORli

Science

All rights reserved

TEST AS A ANXIETY

MARIA DE LOURDES V. SEABRA’, and ROBERTO ANDREATINI’

’ Departamento

de Psicobiologia, Universidade Federal de Sao Paulo Escola Paulista de Medicina, S%o Paulo, SP, Brazil 2 Laboratorio de Fisiologia e Farmacologia do Sistema Nervoso Central, Departamento Farmacologia, Universidade Federal do Parana, Curitiba, Parana, Brazil (Final form, June 1999)

de

Abstract Leite, The video-recorded

de Lourdes V. Stroop Color-Word Test as

A. Sartori and Roberto new model of PP. 809-822.01999

El=er

scienceInc.

The of the Stroop Color-Word as a model of was evaluated. 2. the authors examined the influence of and the of instructions on anxiety state level. 50 State-Trait Anxiety Scale in anxiety state (2 minutes) and error was blocked by 5.0 p.o. on pre- and post-test measures, but was not changed by placebo administration. 3. public performance simulation was effective to the anxiety state on 30 and 50 on STAI). was prevented 5.0 p.o. but was not prevented with placebo administration. 4. a whole, these the Video-recorded Stroop Color-Word Test is an effective anxiety provoking to detect the effect of standard anxiolytic and stressed the importance of trait anxiety level the instructions on

of variance

(ANOVA),

diazepam

810

J.R. Leiteet al. Introduction

The best procedure the double-blind

for confirmation

randomized

long lasting, involving

clinical trials with anxious

presents

some problems,

among many others that constitute drug effects in terms of anxiety of anxiolytic

the clinical improvement

experiments

effect in clinical compounds elicit

setting.

evaluation

relevant

advantages

indicated

symptoms,

compounds

on normal

drugs (experimentally

by following

and Fisher,

1978). These

to clinical trials: (1) the volunteers

control and homogeneity drug side-effects

test, Stroop

color-word

experimentally-

other authors

et al., 1988).

color

for the initial

methods).

(Stroop,

urinary adrenaline,

that

screening

The induction

ways: (a) laboratory

procedures,

laboratory

procedures

have some

of e.g.

relative

will be recruited easily; (2) rapid execution;

of induced anxiety;

(4) more “pure” anxiety

test, etc.) and simulated

public speaking

(3)

symptoms;

(5)

arithmetical

are the most frequently

Test (SCWT) consists

of submitting

1935). The SCWT induced

heart rate, respiration

the subjects

effect was proposed

physiological

rate, electrodermal

(increase

activity,

in plasma

by Nakano et al. (1978a;

in higher trait-anxiety

in the state anxiety (Cibopogon

volunteers).

level induced

citratus

effect with lorazepam

staph).

(improvement

and

situation

anxiolytic

1978b), but in theirs studies they focused

of state-anxiety

a

etc.) and psychological

changes that can lead to suppose that it is a stress-inducing

as an indirect measure

reduced anxiety

to a cognitive

a color of a colorful word that denotes

et al., 1988; Tulen et al. 1989). The use of the SCWT to evaluate

lemongrass

anxiolytic

procedure

e.g. dental surgery; (c) drug administration,

in which they have to nominate

(distress and anxiety)

performance

anxiolytic

these putative

profile (McNair et al., 1982). Mental test task (mental

Color-Word

condition

(Kilminster

have

induced methods used.

The Stroop conflicting

anxiety

have related

have potentially

volunteers

induced

(b) real life situations,

clearer

is a symptom

Thus, it is difficult to explain

effects (Liebowitz

that many

symptoms

level can be elicited

(Pillard

is

Besides this,

while some authors

depression

with direct anxiolytic

greater

anxiolytic

the core of anxiety disorders.

Thus, how do we make a choice among

public speaking;

e.g. caffeine

(change

such procedure

reduction only (Debus and Janke, 1980). This can be seen in

anxiety

of anxiolytic

higher state-anxiety

different

However,

to test in clinical trials? A rational way is the use of a laboratory

clinically

simulated

patients.

such as the fact that anxiety

with reduced secondary

have

drug effect from animal data is

and thus it is expensive.

effect of tricyclic antidepressant:

related the clinical improvement Animal

anxiolytic

many patients and researchers,

the study with patients

the evaluation

of predicted

performance

drug on

related with

Leite et al. (1986), using a direct approach

by SCWT), did not find anxiolytic

More recently,

Tulen et al. (1991)

effect of the did not detect

using the SCWT and Palma et al. (1994) found that

the

Experimentally induced anxiety by the Stroop Test

SCWT did not cause a significant In the study of anxiolytic variable.

Despite

influence

of this personal

anxiety

situations

increase in anxiety level.

drug effects in normal volunteers,

the control

of the mean

attribute

is not clear.

trait anxiety

in the response

Moreover,

Thus the contradictory

the trait anxiety

among

is an important

experimental

of the subject

may be due to the different results described

above

groups,

the

to experimental-induced

other factor that can contribute

results of the SCWT with benzodiazepines by the subjects.

811

to contradictory

instructions

received

could be due to these two

factors The aim of the present experiementally-induced trait-anxiety anxiety

study

anxiety.

was to verify

Thus, it was investigated

and the video-recorded

of the subjects

submitted

procedure

(DZP), relative

to placebo

of the SW/T the influence

(public performance

to SCWT. Moreover,

drug effect must be sensible to antianxiety diazepam

the utility

as a model

of instructions,

simulation)

of the

in the state-

since a valid test to study anxiolytic

effects of establishing

(PLA), on state anxiety

clinical drugs, the effect of

of subjects submitted

to SCWT

was evaluated.

Methods Subiects Ninety-two

healthy

volunteers

(39 male and 53 female,

with age ranged

years) in good physical healthy, without history of past or current psychiatric or drug abuse and not using any prescribed color-blind.

Each volunteer

medication

into three groups according

the State-Trait

Score (Spielberg

median trait group (between protocol

was approved

accordance

with

by

disorder,

were the subjects.

to their scores obtained

alcohol

No subject was

prior to entering the study gave a written informed

subjects were allocated Anxiety

from 18 to 45

consent.

The

in trait portion of

et al, 1970): high trait group (equal or above

50),

31 and 49); and low trait group (equal or below 30). The study the ethic committee

the 1964 Declaration

of Escola Paulista

of Helsinki and

de Medicina

Brazilian ethic guidelines

and it is in of National

Health Council. Druas Diazepam, gelatinous

5.0 mg (Roche,

Brazil)

capsule, on a double-blind

and glucose

schedule,

were

administered

120 minutes before the test.

orally

in identical

J.R. Leite et al.

812

Anxiety Measure The State Trait Anxiety

Inventory

(STAI) consists of two separated

self-report

scales with

20 items each (scores ranging from 20 to 80). The two scales assess respectively (transitory)

and trait (personality

was translated

and validated

The Stroop Color-Word In the Stroop color-word

characteristic)

to Portuguese

(Spielberg

(Biaggio and Natalicio,

et al., 1970).

It

1979).

Test

Color-Word

Test (SCWT)

card. The word card had

three basic cards were used: word, color and

five color names (red, green, yellow,

printed in black letters on white background name appearing

levels of anxiety

population

the state

and set randomically

blue and violet)

in a 10x10 matrix,

20 times, but with the caution that each color appears twice

each

in each row and

did not occur next to itself in any line. These criteria were also used to construct the color and color-name

cards. The color card was made with each color printed with its corresponding

color (e.g. the word red printed printed in an incongruous

in red ink). The color-word

card consisted

of color names

color (e.g. the word red printed in yellow ink). The task was to read

aloud the color names (card word) or color ink (cards color and color-word). Procedure Experiment tested

I- Ten subjects

in two different

of each trait anxiety

sessions,

need for both speed and accuracy in the execution was evaluated

level group (high, median

1 month apart. In Session

before the instructions

(baseline)

I the instructions

and after the SCWT (post-test)

but added with the advice that the task in the third card (color-word) and any error was signalized

considered

were: loss of sequence

stressed

the

of the 3 cards of the SCWT. State-anxiety

portion of the STAI. In Session II the subject received the same instructions

minutes

or low) were

by a sound

of colors, repetition

of a ringing

by the state

described

above

should be done within 2 bell. The types

of error

of colors, mixed up of colors by words

and each color that was not read aloud because the time finished. Experiment

II- The test procedure

is the same of the Session II of the Experiment

with limited time and error signal on color-word

card). The state-anxiety

state portion of STAI before drug administration SCWT (post-drug), Experiment submitted

(baseline),

was evaluated

I (SCWT by the

after drug intake and before the

and after the SCWT (post-test).

Ill- Two groups with 18 volunteers

to the color-word

the second group received

in each were tested. In the first group was

card of the SCWT with limited time (2 minutes) and error signal; the same task but the test execution

was recorded

by a video-

Experimentally induced anxiety by the Stroop Test

camera and

and the image was simultaneously

the experimenter.

posterior

analysis

before

(basal),

It was told to the volunteer

of his(her)

Stroop Color-Word

projected

performance.

monitor to the volunteer

that the videotape

This later situation

Test (VRSCWT). State-anxiety

after reading

in a television

813

be used to

was called Video-Recorded

was evaluated

fifty colors, which correspond

would

by the state portion of STAI

to half of the color-word

card

(during), and at the end of the SCWT (post- test). Experiment

IV- Sixteen subjects were randomly assigned to one of two groups (placebo

diazepam

- 5 mg p.o.) under double-blind

submitted

to the VRSCWT.

State-anxiety

the same moment of the Experiment

condition.

Two hours later, the subjects

state was evaluated

or

were

by the state portion of STAI at

III (basal, during and post-test).

Data Analysis The statistical groups

was evaluated

Friedman

was performed by

ANOVA followed

Differences other

analysis

in baseline

with non-parametric

Mann-Whitney by Wilcoxon

U test, while

matched-pairs

scores in each experiment

methods.

within

signed-rank

were evaluated

Difference

effect

was

between

evaluated

by

test when appropriated. by the raw data. At the

phases, the delta phase value (phase score minus baseline) was used.

Results Experiment

I

Figure 1 presents the results of the two types of instructions anxiety

levels, In Session

Session

II (with

increase

in state-anxiety

from baseline to post-session

showed

group. In

a significant

(T= 0.00; p c .02), while subjects with

only showed a trend to increase (T= 5.5; .I0 > p > .05) and the low trait

group had no change (T= 14.5; p > .lO). Besides this, the delta value (post- session

score minus baseline .05), with anxiety

at any trait- anxiety

limited time and error signal) the high trait subjects

median trait anxiety anxiety

I there is no change in state-anxiety

of the SCWT in different trait-

score) differed significantly

the high trait-anxiety

among the three groups (H2,30= 6.14;

group with higher state-anxiety

group (U= 17.0; p < .05), and the median trait anxiety

(difference

not significant

relative

Session II was only significant

to other groups).

in high trait-anxiety

p <

score relative to the low traitgroup in intermediate

The delta value between

group (T= 8.50; p < .05).

position

Session

I and

J.R. Leite et al.

814

WITH ERROR SIGNAL

ERROR SIGNAL AND TIME LIMIT

WITHOUT

AND TIME LIMIT *

50 r

LOW

MEDIAN

HIGH

LOW

MEDIAN

HIGH

TRAIT ANXIElY 10 BASELINE

I

POST-TEST]

Fig 1. Effect of instructions of Stroop Color Word Test (SCWT) and trait-anxiety level on stateanxiety score (STAI) of normal volunteers (10 per group). Left side: SCWT without limited time and error signal; right side: SCWT with limited time and error signal. Data represents mean + S.E.M. * significantly different from baseline

* q PlA

+ DZP

45

40

35

30 L

BASELINE

POST-DRUG

POST-TEST

Fig 2. Effect of diazepam (DZP), 5.0 mg p.o., or placebo (PLA) on state-anxiety score (STAI) of subjects with high trait-anxiety level submitted to SCWT with limited time and error signal (10 per group). Data represents mean + S.E.M. l significantly different from baseline in DZP group + significantly different from post-drug PLA group # significantly different from pre-drug in PLA group

Experimentally induced anxiety by the Stroop Test

Experiment Figure

II

2 shows

submitted

815

the effect of diazepam

to the SW/T

in state-

anxiety

of high trait-anxiety

with limited time and error signal. There is a significant

after DZP ( xzr= 10.34; p < .Ol) and a significant

state-anxiety

p c .002). In DZP session there is a decrease

in state-anxiety

subjects

reduction

in

increase after PL4 (xzr= 12.67; in post-drug and post-test score

(T=O.OO; p < .Ol and T= 1.50; p < .02, respectively).

The PLA session

showed an increase

in state-anxiety

(T= 0.00; p < .Ol)

and a trend relative

to baseline

relative

between

to baseline

score in post-test relative to post-drug

(T= 8.00; .I0 > p > .05). There was a significant

difference

PLA and DZP post-test score (T=O.OO; p c .Ol).

I A

*

scwr

-+vRSCwr

3oT

BASELINE

DURING

POST-TEST

Fig 3. Effect of video-recorder of SCWT with limited time and error signal (VRSCWT) on stateanxiety score (STAI) of subjects with median trait-anxiety level. SCWT with limited time and error signal without video-recorder was used as control procedure (16 per group). Data represents mean f S.E.M. * significantly different from baseline and post-test in VRSCWT.

Experiment

Ill

The Fig 3 shows the influence anxiety

of median-trait

is an increase increase

anxiety

subjects.

in state anxiety

In the group

across the session

during the SCWT relative to baseline

7.50, p < 0.02, respectively). anxiety

of video-recorder

with video-recorder

exhibition

on state-

of the SW/T

there

(xzr= 13.09, p < 0.02), with a significant

and post-session

(T= 1.00, p < 0.002 and T=

In the group without video- recorder there is no change in state-

(xzr= 3.80). The difference

the SCWT (U= 117, p < 0.03).

with simultaneous

between

groups was significant

only in delta value during

J.R. kite

816

Experiment

et al.

IV

The effects of diazepam

or placebo

time, error signal and video-recorder increase

in state-anxiety

increase

in anxiety

in state- anxiety (VRSCWT)

scores across the SCWT with limited

are shown

in Fig 4 (STAI). There

score (x*r= 10.75, p < 0.001) in the placebo

score during the SCWT and in the post-session

(T= 1.00, p < 0.02 and T= 2.50, p < 0.03, respectively).

group. There

in contrast

to

is an is an

baseline

In DZP group there is no change on

STAI scores across the SCWT (x*r= 1.35).

* I

PL4

+ DZP

I

I

1

DURING

BASELINE

I

POST-TEST

Fig 4. Effect of diazepam (DZP), 5.0 mg p.o., or placebo (PLA) on state-anxiety score (STAI) of subjects with median trait-anxiety level submitted to the Video-Recorder Stroop Color Word Test (VRSCWT). Data represents mean f S.E.M. * significantly different from baseline in PLA group.

Discussion The results of the present study show that experimental change

the state-anxiety

response

also seems that the procedure and video-record)

is a suitable

of normal volunteers

used in Experiment model

procedures

and personal

attributes

to the Stroop Color- Word Test. It

IV (SCWT with limited time, error signal

for experimentally

induced

anxiety

in subjects

with

median trait anxiety. The Role of Trait Anxiety and Instructions In the Experiment submitted

I there was no change in state-anxiety

to the “traditional”

of any trait-anxiety

group when

form of the SCWT. which was similar of results of Palma et al.

Experimentally

(1994). However,

induced anxiety by the Stroop Test

when the level of difficulty of the task was increased

817

by limiting the time to

perform the task and the stress was increased by the signal of the errors committed, with high trait-anxiety

showed a significant

by DZP 5 mg (Experiment baseline (post-drug

measure).

volunteers”

(Brauzer

induction

to study

resemblance clinical

anxiolytic

patients,

use of such subjects The importance

through

The modifications

volunteers”

population

some

and their refuse to participate

in

the negative

with the

results

et al., 1995).

of experimentally-induced response

to the SCWT

results found in some studies

of Palma et al. study (Palma et al.,

in the instruction,

introduced

that

in our study stressed the need

in the SCWT here could have affected

and retention

the state-anxiety

in

made the task more stressful and difficult (Dyer, 1973) and

of the task difficult (Jensen

self- image, which may elicit increase in state-anxiety

and Rohwer,

1966), which could

as a threat to the self-concept

or

(Geller and Shaver, 1976; Boucsein and

1980).

Public Performance The introduction on TV screen,

Simulation of the video-cassette

commonly

al., 1982, Guimaraes

recorder

seen in procedures

is a common

proposed

to represent

However,

besides the speaking,

other situations

fear among

the student anxiety

the public performance

like as psychological

of image (McNair et

in median trait subjects

effect of SCWT with public performance

tests, e.g. memory test (Kohnen and Lienert,

a form of unconditioned

and Savage,

exhibition

public performance

et al., 1987), was able to increase state-anxiety

also seen with other psychological public speaking

and the simultaneous

that simulated

Ill). This increase in the anxiogenic

play (James

of

level on the anxiety

could explain

clinical

problems

advantages

induce more errors. The error signal could be interpreted

(Experiment

some

and to the error signal.

different ways. The time limitation

Wend&Suhl,

share

1988; Pieters et al., 1992; Gorenstein

of trait-anxiety

The discrepancy

of speed and accuracy,

there is no need of anxiety

and thus they have some of the practical

may be due to the differences

made learning

“Symptomatic

eliminated

this experiment

(Tulen et al _, 1991). 1994)

effect.

at only

who can be called “symptomatic

1973; McNair et al., 1980),

drug

had high state-anxiety

could be seen after drug administration

like their low rate in general

models.

suggests

and Goldstein,

which could be reduced

these subjects had already

already

(Glass et al., 1981; Antrobus,

the

anxiety

reduction

This suggests that with the subjects,

with anxious

studies,

experiments Thus,

II). However,

and a significant

increase in state-anxiety,

subjects

population reaction

(Geer,

(Deakin

also increases

was

1980).

The

1965) and it is

and Graeff,

1991).

the state anxiety

in

tests (e.g., Kohnen and Lienert, 1980; this study), music

1984) and physical

exercise

(Ferreira

and Murray,

1983). This

J.R. Leite et al.

818

suggests that the public performance the task performed.

is a potent anxiety eliciting procedure

This can be due to the increase

induced by public performance

of self-awareness

There are some requirements

Anxiety

induced;

that an experimentally-induced

of volunteers;

conditions.

It elicits

volunteers

increase in anxiety state; (b) facility

(c) the control the intensity and the quantification

anxiety

researchers

self-limited

more probably

(e) able to detect the effect of

increase

is

easily

aspect,

to perform

met these

state

in normal

since it was found that in pharmacological

refused to participate

anxiety that is detected

the VRSCWT

in anxiety

refused to participated

In this line, none volunteer

The method elicited a subjective Moreover,

and

trait. This is an important

with higher trait anxiety

studies (Antrobusl988).

of anxiety

drugs. The present study showed that the VRSCWT

a quantifiable

with median

subjects

limited.

anxiety have to meet (McNair

(d) it must be simple, easy and rapid to perform; clinical anxiolytic

and self-monitoring

Model

et al., 1982; Griez, 1984): (a) an induction of a reversible

established

of

(Geller and Shaver, 1976).

The VRSCWT as an Experimentallv-induced

in the recruitment

independently

in the VRSCWT.

by the scale used and that is selfand need

only

a small

team

of

to be carried..

The Stroop effect appears 1991). Furthermore, of prior knowledge

to be universal

and

the SCWT is a standardized or familiarity

VRSCVVT over the simulated

of the volunteer

is present in different test (Lezak,

cultures

(MacLeod,

1995), but with low probability

with the test. It may some advantage

public speaking (SPS), probably the most frequently

to

model used

to induced an increase in anxiety state. In the SPS the subject has to prepare a speech about a topic

selected

(Droppleman

at the

moment

of the

test

and

delivered

it before

camera

and McNair, 1971; Lipper and McNair, 1972; McNair et al., 1982). While in some

studies the topic to be selected

is related to a personal

experience

situation

et al., 1997) in others

the topic

of his life (Guimaraes

nonemotional

a video

subject like political or academic

like the most stressful is a non-personal

(McNair et al., 1982; Guimaraes

and

et al., 1987;

1989). Another state-anxiety

aspect that deserves

further consideration

is the sensibility

increase with VRSCWT was blocked by DZP administration.

that the effective

DZP dose used in this study

used in others experimentally

induced anxiety,

of the method.

It is worthy to note

was lower than the effective dose (10 - 20 mg) e.g. simulated

public speaking

(McNair et al.,

1982; Graeff et al., 1985; Guimaraes

et al., 1989). This may suggest a higher sensitivity

VRSCWT.

characteristic

This

is an

interesting

The

since

it can

reduce

the

of the

probability

of

819

Experimentally induced anxiety by the Stroop Test

appearance

of dose-related

Although

side effects in the evaluation

not measured

an objective

index

of new drugs with anxiolytic

in the present study, the performance

of sedation

and cognitive

impairments

Jones, 1987; Tulen et al, 1991), which may be an additional

effect.

in the SCWT can be used as

induced

by drugs (Hooker

advantage

of the VRSCWT.

and

Conclusion The results of the present study suggest that: (1) internal (trait-anxiety) pressure,

error signal and public performance

the state-anxiety Color-Word

response

to the Stroop

simulation)

Color-Word

and external

factors exerts an important

Test; (2) the Video-Recorded

Test is a useful and sensible method to study putative anxiolytic

(time role in Stroop

drugs.

Acknowledqements The authors Palacios supported

would

like to thank Dr. Jose Carlos F. Galduroz

for the assitance by Associacao

in receipt of a fellowship

on drug administration

Fundo de lncentivo

and Esther M. Nakamura-

and medical

a Psicofarmacologia

support.

This study

was

(AFIP). VAS and RA were

from FAPESP and CAPES respectively

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plasma catecholamines and psychological Psychopharmacology 105: 77-83.

Inquiries and reprint request should be addressed Jose Roberto Leite Departamento de Psicobiologia Universidade Federal de S%o Paulo Escola Paulista de Medicina R. Botucatir, 862, lo andar Sao Paulo, SP, Brazil 04023-062 FAX: 0055-Oll5725092 e-mail: [email protected]

et al.

function

to:

during

rest

and

mental

stress,