2257 r r PRE —
~ POST I o——o
210F i? POST I s-~-a

195

135

120

105

90

75

60

45 MODERATE

ALCOHOL,

30 GROUP

SUBJECTIVE DISPLACEMENT (DEGREES PER 3 SEC INTERVAL)

rae ey Sif uy

36045 «54 «6372 9 18 2
TIME IN SECONDS

27

Ficvre 15. Response data for the average number of degrees of subjective displacement resulting from the ac-
celerations (5°/sec* for 12 sec). Pre refers to the response recorded prior to the ingestion of alcohol, while
the Post I and Post II data were obtained, respectively, min and four hours after ingestion, The arrow on
the abscissa indicates the end of the stimulus. The values are plotted in 3-sec intervals; each point is a mean
for 10 subjects.

Tasxx 15.—Product Moment Correlations for the Duration of the Spiral Aftereffect and the Duration of the Rotatory
Sensations for the 12-sec Accelerations and the Decelerations.

Acceleration Durations Deceleration Durations

Group
Pre Post I Post II Pre Post I Post II
+26 .08 +25 +10 =.13 =.15
227 +25 .71* 04 .18 245
+ 81** + 89%* .93* .61* .814* 272%

*p <.05

**p <.01

secondary nystagmus resulting from the pro-
longed (light) decelerations are presented in
Tables 16 and 17. Similar computations for the
duration of the primary nystagmus are presented
in Table 18; for comparative purposes, nystag-

18

mus duration values for a comparable stimulus
(an acceleration) in total darkness are also pre-
sented. Each value represents a mean for five
subjects since each group was divided into a
three-second and an eight-second light sub-group.


TaBLE 9.—Results of the Paired t Tests for the Pre vs. Post I and Pre vs. Post If Comparisons of the Nystagmic
Responses of the High Alcohol Group to the Rotatory Stimuli.

Condition
Measure Comparison. Mental Arithmetic Key Press Reverie
Ace Dec Ace Dee Ace
Displacement Pre vs. Post I 3. 50** 2, 96* 3.97** 3.00* 4, 97
Pre vs. Post IL 2.04 2,43" 1,74 1.38 3.340"
Frequency Pre vs. Post I 5, Agere 4,9) 7. A5*EF 4. 99% 5. 08
Pre vs. Post II 3. 46** 4,02** 3.09 2. 89* 2.75%
Duration Pre vs. Post I 6. 60*** 2.53 5. 18*** 3.17* 5.03%
Pre vs. Post II 4, 37%* 6. 424 3. 32** 2.62* 3.31**
Velocity Pre vs. Post I 2.37* 0.94 2. 65* 1.08 3.39%*
Pre vs. Post II 0.09 0.77 0.07 2. 52* 1.74
*p <.05
**#D <.01
ee D <,001
109 100 0
Stwmucus. seane oecevenarion
MENTAL aRITMME Te
* “ post 1
gn 0
ba cont on od wonenare aoe oe wc Ne
2
3 0 4
é
z
Bx 2
1° © \
\
fog
Le. Yes ux ohne Loa. wt Pees tyt tees
9 a 6 4 Se a @ 90 98 108 1? 126 5 Bose as be es eB 0 ae ae a ae es ten

TIME IN. SECONDS

Ficure 9. Response data for the average number of degrees of slow phase nystagmus resulting from the brake

decelerations, under the Mental Arithmetic condition.
(approximately 0.5 sec), the values are plotted from the start of the deceleration.

are identical to those used in Figure 3.

sponse is recorded in total darkness. The extent
of the suppression appears related to the amount
of alcohol ingested; ie., the high alcohol group

Since the deceleration

cohol group. These

12

(from 60°/sec) was very rapid
Symbols and markings

evidenced larger declines than the moderate al-

effects of alcohol are ap-

parent in the nystagmus response curves for the


Tasux 18.—Means and Standard Deviations for the Duration (in Seconds) of the Primary Nystagmus Resulting from
the Decelerations During Which (8 sec) or Following Which (3 sec) Room Lights Were on. For Purposes of Compari-
son, Similar Data Are Presented for the Acceleration in Total Darkness.

Deceleration Acceleration
Group Interval
Pre Post I Post IT Pre Post I Post II
3 sec M 39.0 39.6 42.6 48.3 47.6 42.7
8D 8.2 14.8 12,3 4.6 7.0 3.7
Control
8 sec M 38.4 42.0 0 53.6 56.5 53.6
sD 27.8 14.2 15,2 13.3 18.1 8.1
3 sec M 46.8 44.4 40.2 60.7 44,1 51.9
8D 8.6 6.2 3.4 10.7 91 4.4
Moderate Alcohol
8 sec M 40.8 33.0 30.0 53.8 46.0 52.0
8D 9.4 TA 9.5 7.9 9.4 11.7
3 sec M 41.4 37.2 38.4 53.6 41.8 45.0
SD 6.5 8.9 10.3 441 3. 6.4
High Alcohol
8 sec M 37.8 31.8 40.2 52.8 30.9 41.6
sD 13.2 4.6 5.8 13.9 8.3 6.8

Because of the small number of subjects in each
of the sub-groups, the data should be interpreted
with caution. Due to the nature of the data, a
visual analysis rather than statistical treatment
was used.

Changes in the nystagmic response, which oc-
curred as a result of the brief intervals of light,
are evident in comparison of the nystagmus re-
sponse curves from the light decelerations and
dark accelerations (compare Figures 3 through
8 with Figures 17 through 20). The primary
nystagmic responses under both light conditions
were weaker than those obtained under dark
conditions. The suppressive effect. of the light
was also evident in the duration of the primary
nystagmus; mean duration values for the dark
acceleration were much longer (Table 18).
While the primary nystagmic response was weak-
ened and shortened, the secondary nystagmie re-
sponse (like the secondary sensation, the sec-
ondary nystagmic response follows the primary

nystagmic response and is in the opposite direc-
tion) began sooner and was of greater amplitude,
see Figure 21. Under dark conditions, the sec-
ondary nystagmic response was too weak and
infrequent to score adequately in most cases.
These suppressive effects of the brief intervals
of light on the primary nystagmic response and
their enhancing effects on secondary nystagmus
support findings in earlier studies.7 §

The small number of subjects in each of the
sub-groups made any analysis of the effects of
alcohol difficult. Comparisons of the duration
of the primary nystagmic response between the
dark and light conditions indicate that the only
trials where the values for the light condition
were as long or longer than the dark condition
occurred following alcohol ingestion (Table 18).
These data provide some support for the idea
that visual fixation, following alcohol ingestion,
was less effective in suppressing the primary
nystagmic response.

22



EE EE

C. Recording. Silver disc electrodes were
taped by the outer canthi of the eyes to record
horizontal components of eye movements. An
electrode on the forehead served as a ground.
Eye movements were amplified and recorded on
an Offner Type T electroencephalograph using
a 3-second time constant. The subjects’ signals
concerning their sensations of rotation were
made by depression of a microswitch, and these
signals were also recorded.

Eye movement calibrations were obtained by
asking each subject to sweep his eyes between
two small, dim, flashing lights (subtending a
visual angle of 15°) attached to the front of the
rotatory device. A switch, located inside the
cabin, allowed the subject to turn the lights off
and on in an otherwise totally dark room, thereby
permitting calibrations both prior to the accelera-
tions and during constant velocity prior to the
deceleration.

Il. Procedure.

The 30 subjects received identical trials during
what are here termed Pre, Post I, and Post II
sessions. These respective sessions were held the
day before drinking, and 45 minutes and four
hours after drinking.

The subjects received three practice trials of
counter-clockwise (CCW) rotations in total
darkness. These practice trials were used to
train the subjects in the technique of estimating
rotational velocity from turning sensations? °*

A. Pre Trials. Following practice, the sub-
jects received three experimental trials of clock-
wise (CW) rotations separated by 5-minute rest
periods. The accelerations on these three Pre
trials were 5°/sec* for 12 seconds followed by
rotation at constant velocity (60°/sec) for three
minutes. Deceleration began after an eye-move-
ment calibration was obtained. On trials 1 and
2, a brake deceleration of 120°/ sec? for 0.5 sec
was used; on trial 3 continuous deceleration at
the rate of 5°/sec? was employed.

During the three Pre trials, the subjects per-
formed different: tasks. On one of the first two
trials, the subject. was instructed to work on a
mental arithmetic (MA) task in the form of a
continuous division problem.’* Different. prop-
lems were given for the acceleration and decelera-
tion periods and the subject’s answers were re-
corded (approximately 114 minutes after the end

of the acceleration and the deceleration) to insure
that the problems were viewed as an important
part of the trial. Following his response, the
subject was allowed to relax until alerted by the
experimenter, On the other of the first two
trials, the subject was instructed to signal his
turning experiences as he had during the train-
ing period. Thus, the subject signaled with a
key press (KP) the start, quarter turns, and end
of his turning sensation for the acceleration stim-
ulus, and the start and end of his turning sensa-
tion for the brake deceleration. After comple-
tion of his signals the subject was told to remain
alert and attentive and to call out and signal
any subsequent turning experience (secondary
sensation). The order in which these tasks were
presented was counterbalanced among subjects.

All subjects were given an identical task for
the acceleration of trial 3. They were instructed
to assume a “Reverie” state, i.e, to relax, day-
dream, and not to pursue particular lines of
thought. The subject was allowed to relax and
daydream for 30 seconds prior to the accelera-
tion, during the acceleration, and throughout the
period of constant velocity until a few- seconds
before the eye-movement calibration was re-
quired; he was then told to make the calibration
eye movements and to prepare himself for de-
celeration. The room lights were turned on
during the first eight seconds of the deceleration
for five subjects in each of the three groups, and
for three seconds immediately after the chair
was stopped for the remaining five subjects in
each group. After the lights went out, the sub-
ject was asked to signal any further turning
sensations and to call out the direction in which
he experienced motion. For those trials during
which the lights were briefly turned on after the
end of the deceleration, the subject signaled his
turning sensation during deceleration (before the
lights were turned on) and again after the brief
period of light. Subjects were instructed to
watch the walls of the room when the lights were
on during the deceleration, and to fixate on
markers attached to the walls of the room while
at a standstill in illumination. The use of the
room lights was designed to provide data regard-
ing the interaction of visual and vestibular stim-
ulation.

B. Post Trials. Post I and Post II rotation
trials were identical to the Pre trials but were


3
é
p80 CONTROL GROUP 80 MODERATE ALCOHOL GROUP 80/- HIGH ALCOHOL GROUP
Zz
° 2
g STIMULUS: 5*/SEC? DECELERATION
60 sor sor 8-SEC LIGHT GROUP
nm = = PRE ee
w " Post 1 O—O
a 40 ik 40 40f PosT 1 &-—&
o - Tih L L
ir] ate
Ser \ 20h 20+
\
ir 7 ee
a | \ - i
2 \ ns
6b O
Zz \ y ° °
wy i L
i no \ A r
2 “rl
5 L L
O40 -40b -40b
w
> L L
-
Goolthi pl Lh tt
3 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI
2
a TIME IN SECONDS
Figcre 16. Response data for the average number of degrees of subjective displacement resulting from the 12-sec
deceleration of 5°/sec*, The room lights were turned on at the start of the deceleration and remained on for
8 sec. Points plotted above the zero line represent the primary response, while those below represent the sec-

ondary response.

19

Symbols and markings are identical to those used in Figure 15.


ar CONTROL GROUP 8 MODERATE ALCOHOL GROUP er ft HIGH ALCOHOL GROUP
\ stimulus:
a \ 5*/ SEC? DECELERATION
g7r 7, an 8-SEC LIGHT GROUP
& PRE @—o
5 Post 1 O—O
26+ 6 4 6p Post 1 A——&
re)
ra
2
5b F
ox
a
4p 4p 4b
o
E
Zz K
3 3 3
wy
8
= \
2b 2b \ 2b
w
¥
iy
Qib th 1 ao
= \
2g .
= _lucurs on ucts on LIGHTS ON
ee) + oO
> me
Zz
\
i v
Cub ah ak
a f
io J
o
B-2b -2ab Vi “2b K ‘A
2 Vial
“WA
pooh shh gh
9 18 27 36 45 54 63 72 81 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI
TIME iN SECONDS
Fievre 20. Response data for the average number of nystagmic eye movements resulting from the 12-sec decelera-
tion of 5°/sec*. Room lights were turned on at the start of the deceleration and remained on for 8 sec. Sym-

bols and markings are identical to those used in Figure 17.

25


ee

TaBLE 16.—Means and Standard Deviations for the Slow Phase Displacement of Primary and Secondary Nystagmus
(in Degrees) Resulting from the 12-sec Deceleration of 5°/sec?. The Room Lights Were on for Either 3 see After the
Deeel or for 8 sec at the Start of the Deceleration.

Nystagmus
Group Light Primary Secondary
Interval
Pre Post I Post II Pre Post I Post II
3 sec M 276.7 251.3 265.4 54.6 54,2 67.5
sD 46,2 57.1 42,2 39.1 41.9 65.5
Control
8 sec M 245.6 235.6 246.3 128.9 81.5 79.8
sD 289.0 205.9 193.0 141.3 72.1 83.7
3 sec M 221.4 282.2 241.1 58.2 73.9 71.5
sD 34.6 97.7 69.8 55.8 36.0 46.9
Moderate Aleohol
8 sec M 156.7 138.3 156.7 48.4 60.1 46.2
sD 93.7 64.1 89.0 42.2 51.7 39.1
3 sec M 258.5 231.5 228.2 44.0 53.9 42.0
sD 162.9 130.2 120.4 40.3 28.3 28.5
High Alcohol
8 sec M 201.6 156.0 243.2 51.4 26.1 80.1
sD 119.4 76.3 88.6 33.0 32.6 23.8

TasLe 17.—Means and Standard Deviations for the Number of Primary and Secondary Nystagmic Eye Movements
Resulting from the 12 sec Deceleration of 5°/see’. The Room Lights Were on for Either 3 see After the Decel or for
8 sec at the Start of the Deceleration.

Nystagmus
Group Light Primary Secondary
Interval
Pre Post I Post If Pre Post I Post II
3'see M 46.6 50.0 52.6 14.6 15.4 15.4
sD 16.1 23.2 24,2 8.8 9.1 9.4
Control
8 sec M 37.2 44.3 36.6 23.0 16.9 22.5
sD 29.1 21.9 19.0 15.1 10. 14,8
3 sec M 46.4 55.5 7. 14.8 18.0 19.1
sD 8.4 9.8 15.4 Wd 7.6 10.8
Moderate Aleohol
8 sec M 32.4 24.1 30.0 15.2 17.2 12.3
sD 20.0 11.6 17.2 13.4 13.0 9.2
3 sec M 46.0 43.2 471 13.0 16.4 14.0
sD 17.7 15.1 18.5 10.9 5.8 8.4
High Alcohol
8 sec M 39.1 27.7 41.4 16.8 14 22.2
sD 21.3 12.9 15.4 10.6 11.8 47



E, Subjective Data from the Accelerations and
Decelerations in Darkness, Means and standard
deviations for the total displacement (in degrees)
and duration of the rotatory sensations resulting
from the accelerations, and for the duration of
the rotatory sensations resulting from the de-
celerations are presented in Tables 10 and 11.
Response curves for the subjects’ estimations of
turning velocity during the accelerations are pre-
sented in Figure 15. Analyses of variance
(Table 12) were applied to these data.

Taste 10.—Means and Standard Deviations for the Total
Subjective Displacement (in Degrees) for the KP
Acceleration (Total Darkness).

Trial
Group

Pre Post I Post IT

Control M 1368 1350 1269
sD 703.3 468.6 477,

Moderate M 1323 1224 1287
Alcohol SD 511.0 728.9 578.7

High M 1107 945 918
Alcohol sD 395.8 360.6 257.4

1. Accelerations. Pre to Post I declines in
mean experienced velocity and duration of the
turning sensations for the moderate and the high
alcohol groups were larger than those for the
control group. Although the largest declines oc-
curred for the high alcohol group, the F ratios for
these data were not significant (Table 12). Even
though the Post II means for the velocity and
duration measures of the rotatory sensations evi-
denced some recovery from the Post. I level, they
were still below Pre levels.

2. Decelerations. Results of the analysis of
variance (Table 12) indicated that changes across
trials in the duration of the turning sensations
resulting from the decelerations were significant.
The Pre to Post I declines in the durations, ac-
cording to t tests, were significant for both alcohol
groups but not for the control group (Table 13).
None of the Pre-Post II differences were sig-
nificant. That the declines in the duration meas-
ures were significant for the decelerations, but
not for the accelerations, may be due to the fact
that, during the acceleration, the subjects were
required to make signals concerning the velocity
of their sensations between the start and end
of their turning sensations, whereas they needed
only to signal the start and end of their turning
experience during the deceleration. ‘The addi-
tional signals may have maintained alertness and
thereby prevented the response from decaying
as rapidly as it did under the acceleration con-
dition.

3. Overview. The data from the decelerations
support the conclusion reached by Barany?;
alcohol ingestion tends to suppress the sensations
resulting from rotatory stimulation. Moreover,
some declines were evident for the velocity and
duration of the turning sensations from the ac-
celerations, although they were not statistically
significant. This difference in the magnitude of
decline of the turning experience between the
accelerations and decelerations may be due to
differences in instructions concerning attention
to (and signals of) rotatory sensations.

F. Spiral Aftereffect Data. Means and stand-
ard deviations for the spiral aftereffect (SAE)

Tanie 11—Means and Standard Deviations for the Duration (in Seconds) of the Subjective Turning Sensations Re-
sulting from the KP Acceleration and Deceleration. Each Group Was Comprised of Ten Subjects.

Pre Post I Post II
Group

Ace Dec Ace Dec Acc Dec

Control M 30.8 31.5 36.6 32, 32.2 31.7
sD 9.5 11.5 16.3 11.9 13.0 19.6

Moderate M 26.6 28.5 25.6 23.3 25.4 25.1
Alcohol SD 10.2 9.4 8.2 9.7 U7 7.7
High M 28.0 31.1 27.7 23.0 26,2 24.6
Alcohol sD 10.3 8. 8.4 9.4 10.8 14.6



a

8

8

&

CONTROL
Grou

8 8

SLOW PHASE NYSTAGMUS (DEGREES PER 3-SEC INTERVAL)
5

9 18 27 36 45 84 63 72 al

(MENTAL ARITHMETIC)
PRE

"T 20) STIMULUS: 5*/ SEC? FoR 12 SEC

post 1 oo
rob Oh Post D a——e

9 8 27 3% 43 34 63 72 a 90 9 8 27 3% 45 54 63 72 Bt
TIME IN SECONDS

Fiaure 3. Response data for the average number of degrees of slow phase eye movement resulting from the angu-
lar accelerations (5°/sec’ for 12 sec), under the Mental Arithmetic condition. Pre refers to the response re-
corded prior to the ingestion of alcohol, while the Post I and Post IT data were obtained 45 min and four hours

after ingestion. ‘The arrow on the
intervals; each point is a mean for

o

. ow 2 a a ~

NUMBER OF NYSTAGMIC EYE MOVEMENTS PER 3-SEC INTERVAL

abst indicates the end of the stimulus. The values are plotted in 3-see
10 subjects.

°r STIMULUS: 5*/ SEC? FOR 12 SEC
MENTAL ARITHMETIC
PRE Oe
er Post 1 O—O
Post a-— a.
7b

MODE RATE
ALCOHOL
GROUP.

ibis

9 18 27 36 45 54 63 72 BI

9 18 27 36 45 54 63 72 B 90 9 18 27 36 45 54 63 72 BI
TIME IN SECONDS

Ficvre 4. Response data for the average number of nystagmie eye movements resulting from the angular accele-
rations (5°/sec* for 12 sec), under the Mental Arithmetic condition. Symbols and markings are identical to

those used in Figure 3.




BE Eee

Tapie 2.—Means and Standard Deviations for the Slow Phase Nystagmus Displacement (in Degrees) Resulting from
the Rotatory Stimuli. Each Group Was Comprised of Ten Subjects.

Mental Arithmetic Key Press Reverie
Group Stimulus
Pre PostI PostII Pre Post PostII Pre Post I Post II
Ace M 567.7 495.2 474.9 514.1 466.2 448.4 339.6 298.0 321.9
sD 183.7 194.5 204.3 205.4 288.2 165.4 83.3 108.7 83.6
Control
Dee M 668.5 759.8 597.0 523.2 492.3 475.3. Interrupted by visual
sD 354.2 442.1 231.1 285.8 347.5 192.9 stimulation
Ace M 467.1 421.2 538.6 411.6 396.3 505.3 293.9 227.2 336.3
sD 127.3 95.6 156.8 143.8 93.0 184.0 126.9 83.8 156.6
Moderate Alcohol
Dec M 443.8 380.8 475.5 359.2 347.5 421.9 Interrupted by visual
sD 157.6 141.3 195.9 146.2 157.6 169.6 stimulation
Ace M 582.7 307.9 431.7 493.4 315.1 412.9 377.9 184.1 256.7
sD 313.6 133.7 207.9 211.9 178.2 173.4 168.6 119.2 110.7
High Alcohol
Dec M GO1.3 332.4 402.1 414.9 283.6 369.6 Interrupted by visual
sD 343.1 156.0 181.5 189.8 159.1 145.4 stimulation

TABLE 3.—Means and Standard Deviations for the Number of Nystagmic Beats Resulting from the Rotatory Stimuli.
Each Group Was Comprised of Ten Subjects.

Mental Arithmetic Key Press Reverie
Group Stimulus
Pre Post 1 Post II Pre Post1 PostIl Pre Post I Post II
Ace M 76.6 79.6 77,2 72.1 78.1 75.7 67.7 61.8 67.2
SD 19.7 21.5 22.6 21.4 21.3 16.8 16.9 23.6 18.3
Control
Dee M 92.4 105.3 97.3 77.0 80.7 81.4 Interrupted by visual
sD 37.1 49.8 37.6 31.7 36.7 32.9 stimulation
Ace M 76.9 56.4 74.3 714 55,2 72.3 64.3 46.3 61.0
sD 30.6 15.6 22.2 27.9 15.5 20.5 28.6 12.8 20.3
Moderate Alcohol
Dec M 68.3 48.4 65.2 60.4 48.8 63.5 Interrupted by visual
8D 25.9 14,2 19.7 23.2 14.5 14,1 stimulation
Ace M 77.9 43,2 59.8 75.9 40.4 59.6 71.5 38.9 56.1
sD 33.4 17.5 21.4 25.9 17.5 20.4 23.9 18,2 16.0
High Alcohol
Dec M 80.8 48.8 60.0 68.7 42.8 55.7 Interrupted by visual
SD 31.9 18.0 19.5 23.7 18.3 17.5 stimulation
two different alertness levels (MA and Rev) on C. Nystagmus Recorded in Darkness. Means

the nystagmic response to angular accelerations. and standard deviations for the slow phase dis-
The effects of alertness are also evident in the placement, frequency, peak velocity, and dura-
response curves for the slow phase displacement tion of the nystagmic eye movements resulting
and the frequency of the nystagmic responses from rotatory stimuli administered in total dark-
(Figures 3 through 8). ness are presented in Tables 2 through 5. The


conducted on the following day after consump-
tion of alcohol (or of the non-alcoholic control
beverage).

C. Visual Fivation Trials, Seven additional
subjects received angular stimulation while at-
tempting to fixate visually, The rotatory stim-
uli for these subjects was again a 5°/sec? accelera-
tion for 12 seconds, three minutes at constant
velocity, and a brake deceleration. The only
difference involved the use of visual fixation
throughout the trials. During the acceleration
with the room lights off, the subject fixated on a
dimly illuminated target which rotated with him.
The subject fixated on the same target following
the brake deceleration; however, in this instance
the room lights were turned on. These trials
were administered a few minutes before and 45
minutes after drinking.

D. Alcohol Ingestion and Blood Tests. Sub-
jects in the moderate and high alcohol groups
drank a mixture of 100-proof Smirnoff vodka
and orange juice. The mixture contained either
2.5 ml or 1.25 ml of vodka per kilogram of body
weight for the high and moderate alcohol groups
respectively. The control group drank orange
juice with a few drops of rum extract added to
alter the taste somewhat. Subjects who re-
ceived rotatory stimulation while fixating on
visual targets consumed a mixture which con-
tained 2.00 ml of vodka per kilogram of body
weight. All subjects consumed their drinks in a
15-minute period.

Venous blood samples of from three to five ml
were drawn a few minutes prior to drinking,
then one-half hour, one hour, and four hours
after consumption of the alcohol. The blood
alcohol levels were determined by means of gas
chromatography.

E. Scoring. The nystagmus was scored with
respect to (a) duration or the time from the
start of the stimulus to the last nystagmic beat,
(b) frequency or the number of nystagmus beats,
(c) slow phase displacement or the total number
of degrees of eye movement in a three-second
period, and (d) slow phase velocity (degrees/
sec) at peak slow phase displacement. Slow
phase eye displacement was determined by meas-
uring (in millimeters) the amplitude of each
nystagmic beat from slow phase peak to base-
line. These measures were summed for all the
beats in each three-second interval and the sum

converted, using the calibrations, into degrees of
slow phase eye movement. From Bodin’s form-
ula, the velocity of the slow phase eye movement
was calculated from the average angle of the
slow phase of the nystagmus during the three-
second interval where the nystagmic output was
maximum.

III. Results and Discussion.

A. Blood Alcohol Levels (BALs). Means and
standard deviations for the blood alcohol levels
are presented in Table 1. The mean level for the
high alcohol group after one hour was 90 mg.%,
nearly twice the average value (52 mg.%)
reached by the moderate alcohol group. Four
hours after ingestion, the mean BAL for the
moderate alcohol group was reduced to 19 mg.%,
while the average for the high alcohol group (65
mg.%) was above the values reached by the mod-
erate alcohol group at either the 30-minute or
the one-hour testing session.

TanLe 1.—Means and Standard Deviations for the Blood
Alcohol Levels (in mg per 100 ml). Each Value is
Based on a Mean for 10 Subjects.

‘Time Since the Ingestion of

Alcohol
Group

Thirty One Four

Minutes Hour —_ Hours

Moderate M 44.6 52.1 18.6
Alcohol SD 14.1 10.9 3.8
High M 64.2 90.0 64.7
Alcohol SD 19.7 18.0 10.1

B. Alertness. The mean response levels under
the alert conditions in the KP and MA trials
were, for most trials, higher than those under the
relaxed (Rev) condition (Tables 2 through 5).
Analyses of variance for all measures of the
nystagmic responses to the angular accelerations
revealed significant effects for “instructions”
(Table 6). While supporting the conclusions
reached in earlier studies* ** that alerting instruc-
tions produce a higher-amplitude, longer-dura-
tion response, the present data further indicate
that alerting instructions result in an increase in
the frequency and the slow phase velocity of
vestibular eye movements. The nystagmic trac-
ings presented in Figure 2 depict the effects of


BN eee

TaBLE 12.—Results of the Analyses of Variance for the Displacement (in Degrees) and Duration (in Seconds) of the
Subjective Reactions During the KP Rotation Stimuli.

Subjective Displacement Duration Duration
(Accelerations) (Accelerations) (Decelerations)
Source df
Mean F Mean F Mean F
Squares Squares Squares
Groups (G)_-_-_--_..- 2 1002.33 1.54 45.61 1.54 33.99 1.05
Subj./within Groups(S/G) 27 649.41 59.37 32,40
Trials (T) 2 102. 69 1.33 3.32 1.15 14.69 3. 88*
4 27.36 0.35 3.45 1.20 5.33 1.41
54 77.10 2.87 3.79

*p <.05

Taste 13.—Results of the Paired t Tests for the Duration
of the Rotatory Sensation Resulting from the KP
Deceleration.

Group Pre vs. PostI Pre vs. Post II
0.21 0,04
2.66* 1,62
4.11% 1.97
*p <.0:
**p <.01

Taste 14.—Means and Standard Deviations for the
Duration (in Seconds) of the Spiral Aftereffect (SAE).
Each Group Was Comprised of Ten Subjects.

Trial
Group a
Pre Post I Post IT
Control M 12.7 13.0 12.8
sD 6.4 6.3 7A
Moderate M 15.3 13.0 14,1
Alcohol sD 7.2 5.4 6.1
High M 14,2 13.8 15.1
Alcohol sD 10.1 1.9 16.1

are presented in Table 14. Comparisons of the
Pre, Post I, and Post II values reveal little
change as the result of the ingestion of alcohol.
The relationship between the duration of the
SAE and the duration resulting from the ac-
celerations and decelerations of the rotatory
stimuli was investigated. Only the correlations
for the high alcohol group were significant
(Table 15). Thus, these data offer only partial
support to the studies by Reason,* 1” Reason and
Benson,” and Nilsson and Henrikson? The

lack of significant correlations among the meas-
ures may be due to the lack of appreciable
variability in the SAE duration values for the
control and moderate alcohol groups; or to sev-
eral differences in experimental technique be-
tween earlier studies and this one.

G. Subjective Data from the Deceleration
which Involved Brief Intervals of Light. The
analysis of the data concerning the subjective
sensations resulting from the decelerations using
either a three-second or an eight-second period
of room illumination was based on visual obser-
vation rather than on any statistical treatment
of the data. There were no dramatic changes
in the response which could be attributed to the
ingestion of alcohol.

When compared to the experiences reported in
total darkness (using a comparable angular
stimulus) the primary sensations from the “light”
decelerations were much shorter. The “light”
intervals also tended to increase the occurrence
and intensity of secondary sensations (ie, a
renewal of sensations which follows the end of
the primary response and is in the opposite di-
rection). These differences are evident when you
compare Figures 15 and 16.

Under dark conditions, the secondary sensa-
tion, in most cases, was either not present or was
too weak to be signaled. Even with the small
number (five) of subjects in each of the sub-
groups, the data appeared to agree with results
obtained in studies by Collins.’ ®

H. Vystagmus Data from the Deceleration
which Involved Brief Intervals of Light. Means
and standard deviations for the slow phase dis-
placement and frequency of the primary and

17


EEE EE

STIMULI: 5YSEC? FOR 12 SEC
ALCOHOL

INGESTION

mre Ennoite MO oan nnan

aor AWW Nae

POST}
SUBJECT DM
‘CONDITION
NS Ww Mw SARA Na AAAS
cet ates Nanny" AW vw
WARIS St SSIS RUA
reverie SL

Ne

SUBJECT BG

Figure 2. A portion of the nystagmic tracings, for two subjects, resulting from a 12-see acceleration of 5°/sec*.
Calibrations (15° of eye movement) appear before each trial. The vertical bars demarcate the stimulus period
and the arrows indicate the end of the primary nystagmic response. The tracings for subject DM reveals the
Suppressive effect of the high alcohol dose on the n: onse (Mental Arithmetic condition). All as-
pects of the Post I nystagmic response are suppressed (slow phase displacement, frequency, peak velocity and
duration of the nystagmus). The tracings for subject BG in the lower half of the figure (both taken from
Pre trials) reflect the influence of alerting instructions (Key Press) on the nystagmie response. All measures
of the nystagmic response during the Alert condition are enhanced in comparison with the Reverie condition.

TaBLE 6.—Results of the Analyses of Variance for the Various Measures of the Nystagmic Responses Resulting from
the Rotatory Stimuli.

F
Source
Slow Phase Frequency Duration Peak Velocity
Displacement
Groups (G)__- - 0.62 1.85 2.98 1.40
Instructions (1). 32. 1284* 6.674* 36. 02*#* 15,9404
IxG._.. - 0.06 0.46 1,48 0.56
Trials (Tr) . 15, 98##* 28. 14*** 33. 30*** 8, 44008
Trx G_- 7.15 10. 21*# 9.9784" 2,61*
IxTr 0.72 0.35 0.50 0.45
Ix Trx Gee 0.56 0.58 0.22 0.74
*p <.05
*eD <.01
ee D <.001


CONTROL GROUP 97 = MODERATE ALCOHOL GROUP or HIGH ALCOHOL GROUP
STIMULUS: 5*/ SEC? DECELERATION
sr 8r 3-SEC LIGHT GROUP
PRE @—®
Post 1 O—O

Post  #--a

3-SEC INTERVAL

NUMBER OF NYSTAGMIC EYE MOVEMENTS PER
T

LIGHTS ON LIGHTS ON \
|_ —m o}—=— 7
\
“IF ab tA
f
‘ f \W
-2b cab {> 2h MI
\) ‘
\
\t
“3b Ul -3E
‘|
H
gleth gh gly
9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 81 90 9 18 27 36 45 54 63 72 BI 90

TIME IN SECONDS
Fiavre 18. Response data for the average number of nystagmic eye movements resulting from the 12-sec decelera-
tion of 5°/sec*, Following deceleration, room lights were turned on for 3 sec, during which time the subject
fixated on a target. Symbols and markings are identical to those used in Figure 17.

23


EEE EEE

TECHNICAL REPORT STANDARD TITLE PAGE

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.
FAA-AM-71-16
4. Title and Subtitle 5. Report Date
ALCOHOL AND DISORIENTATION-RELATED RESPONSES. II. April 1971

NYSTAGMUS AND "VERTIGO" DURING ANGULAR ACCELERATION 6. Performing Organization Code

7. Author's) 8. Performing Organization Report No.

David J. Schroeder, Ph.D.

9. Performing Organization Name and Address 10. Work Unit No.
FAA Civil Aeromedical Institute
P. 0. Box 25082 11. Contract o¢ Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report and Period Covered

12. Sponsoring Agency Name ond Address OAM Report
Office of Aviation Medicine
Federal Aviation Administration
800 Independence Ave., S. W.
Washington, D, C, 20590

14. Sponsoring Agency Code

15. Supplementary Notes

This study was conducted under tasks AM-B-69-PSY-10, AM-A-70-PSY-10,
and AM-A-71-PSY-27,

16. Abstract
The integrity of the visual and vestibular systems is important in the mainte-
nance of orientation during flight. Although alcohol is known to affect the
vestibular system through the development of a positional alcohol nystagmus,
information concerning the effects of alcohol on "vertigo" and eye-movement
(nystagmus) responses to angular acceleration is contradictory. Several
investigators have reported that alcohol enhances these responses, while
others have reported suppressive effects. This study was designed to
investigate the effect of alcohol ingestion on both "vertigo" and nystagmic
responses to angular stimulation. Responses were obtained (a) with and
without visual fixation, and (b) with the alertness of the subjects controlled.

When recorded in total darkness, the nystagmic response to rotatory stimulation
was suppressed by the alcohol. When visual fixation was allowed, a high-frequency
low-amplitude nystagmus to rotation was obtained following alcohol ingestion;
there was little or no response prior to drinking. This apparent enhancement

of the response was not due to an increase in vestibular sensitivity but, rather,
to the suppressive effect of alcohol on the ability of the subject to maintain
adequate visual fixation. "Vertigo" sensations resulting from the rotatory
stimuli evidenced only slight declines following alcohol ingestion.

17. Key Words , 18. Distribution Statement oa
Alcohol, Nystagmus, Vestibular, Visual Availability is unlimited, Document may
Fixation be released to the National Technical
Information Service, Springfield,
Virginia 22151, for sale to the public.
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21- No. of Pages | 22. Price
$3.00
Unclassified Unclassified 27

Form DOT F 1700.7 (8-69)


8

8

2
&

8

CONTROL,

8

3

60
sor nN
i\
ii
\
40 4
i
\
|
\
\\
30h

60 sTimutus: 5*/ SEC? FOR 12 SEC
(REVERIE)
PRE oe
Post I o—o
Sor Post m 4-4
40h
sob

MODERATE HIGH
ALCOHOL ALCOHOL
GROUP GROUP

a duitiit 1

SLOW PHASE NYSTAGMUS (DEGREES PER 3-SEC INTERVAL)

woh
9 18 27 36 45

TIME IN SECONDS

54

it
63 9 8 27 36 54 63

Ficure 7, Response data for the average number of degrees of slow phase eye movement resulting from the angu

lar accelerations (5°/sec* for 12 sec), under the Reverie (relaxed) condition.

tical to those used in Figure 3.

Symbols and markings are iden-

or or or STIMULUS: 5*/SEC? FOR I2 SEC
REVERIE
2
zg PRE oe
fer get BE BF POST 1 O—O
= PosT T Ap
z
Qe7b L rm
Br 7 ' 7H |
" H
« t
ger 6 6 }
g !
é |
=5r 5 5
3
co}
=
war 4 4
¥
rf
Q
= 3h
3 3 3 3
&
Z
22H 2 2
u
6 ALCOHOL
« 1 ConTROL MODERATE GROUP
g! GROUP 1 avcoHon I
GROUP
2 a
itt 1 tar Fey itt Loitiat
9 18 27 36 45 54 63 9 18 27 36 45 54 63 9 18 27 36 45 54 63 72 BI

Fievre 8. Response data for the average number of ny:
rations (5°/sec* for 12 sec), under the Reverie (rel:

those used in Figure 3.

TIME IN SECONDS

ed)

10

tagmic eye movements resulting from the angular accele-
condition,

Symbols and markings are identical to


2 od er STIMULUS : 5*/SEC? FOR 12 SEC
(KEY PRESS)

PRE oe
Post 1 oo

3 ror vor POST a——-a

é

e A

2 wr ~\

¢ ‘

g ‘

6

£ sob

a

®

8

Fe

§ “or

2 MODERATE

z sor ‘ALCOHOL

2 GROUP

z

&

g

2 20)

Fa 10

8

a

9 8 27 36 45 54 63 72 BI 90 9 8 a 36 45 58 63 72 al

TIME IN SECONDS.

Fieure 5. Response data for the average number of degrees of slow phase eye movement resulting from the angu-
lar accelerations (5°/sec* for 12 sec), under the Key Press condition. Symbols and markings are identical
to those used in Figure 3.

or or or STIMULUS: 5*/SEC? FOR I2 SEC
KEY PRESS
a PRE =@—®
ar IN Bt Bt PosT I OO
Post 1 a
‘
7 \
? L
f\
t \
6 6 4
\

o

B

o

iy

CONTROL MODERATE

NUMBER OF NYSTAGMIC EYE MOVEMENTS PER 3-SEC INTERVAL

GRouP ALCOHOL
GROUP

tetas jl iba j Ns

9 18 27 36 45 54 63 72 BI 90 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI

TIME IN SECONDS

Ficcre 6, Response data for the average number of nystagmic eye movements resulting from the angular accele-
rations (5°/sec* for 12 sec), under the Key Press condition. Symbols and markings are identical to those used
in Figure 3.






Taiz 4.—Means and Standard Deviations for the Peak Velocity (Deg/Sec) of the Slow Phase Nystagmus Resulting

from the Rotatory Stimuli. Each Group Was Comprised of Ten Subjects.

Mental Arithmetic Key Press Reverie
Group Stimulus
Pre Post PostIl Pre  PostI PostII Pre  PostI Post Il
Ace M 37.3 36.3 87.5 41.2 35.0 40.6 «29.8 25.4 81.9
sD 7.4 124 118 121 116 86 9.0 9.6 7.0
Control
Dee M 46.8 54.8 53.1 61.4 59.2 56.6 —_Interrupted by visual
sD 17.9 20.0 17, 19.3 15.38 11.3 stimulation
Ace M 32.1 32.3 35,1 29.4 32.4 36.8 25.8 26.0 31.7
sD 10.1 97 9.5 118 80 13.7 84 124 144
Moderate Alcohol
Dec M 41.4 45.2 41.8 39.1 46.1 48,5 —_ Interrupted by visual
sD 17.2 16.8 183 16.8 14.6 16.1 stimulation
Ace M 35.6 26.2 35.3 35.8 24.1 35.5 28.5 18.2 242
sD 16.4 6.7 154 164 107 89 89 9.2 7.9
High Alcohol
Dee M 48.6 43.6 43.7 46.0 39.0. 54.6 Interrupted by visual
SD 25.4 11.2 19,3 14.5 21.4 14.1 stimulation

Taste 5.—Means and Standard Deviations for the Duration (in Seconds) of the Nystagmic Response Resulting from

the Rotatory Stimuli. Each Group Was Comprised of Ten Subjects.

Mental Arithmetic Key Press Reverie
Group Stimulus
Pre PostI Post II Pre  PostI Post Il Pre Post Post II
Ace M 53.4 52.8 51.0 B10 52.2 48.2 45.844 4B.
sD 8.6 84 114 98 13.9 8 72 7.8 3.0
Control
Dee M 59.1 62.2 57,6 52.2 55.1 48.6 Interrupted by visual
sD 19.2 27.6 21.9 24,2 28,3 :19.0 stimulation
Ace M 61.1 49.1 56,4 55.6 45.1 52.0 45.4 85.0 42.6
sD 13.6 7.6 110 115 88 83 98 84 8.1
Moderate Alcohol
Dec M 54.5 40.2 46.8 47.3 36.2 © 41.6 Interrupted by visual
sD 13.0 7.1 TA 5.9 5.3 85 stimulation
Acc M 58.4 39.1 43,9 53.2 36.4 48.3 46.6 80.4 88.5.
sD 10.7 7.2 7.0 9.6 838 6.5 5.5 12.2 10.6
High Alcohol
Dec M 53.1 37.6 39.0 44.8 © 80,1. 35,4 Interrupted by visual
sD 13.2 18.7 87 8.0 125 9.2 stimulation

results of analyses of variance for the accelera-
tion data are presented in Table 6. Since the
“trial” factor was significant for all measures,
t tests were conducted to determine where the
significant changes occurred.

Although most of the measures evidenced some

degree of Pre-to-Post I decline for the control
group, only the decline in slow phase displace-
ment for the MA acceleration (.01 level) and
the decline in velocity for the KP acceleration
(.05 level) were significant. Only one of the Pre-
to-Post IT differences was significant (Table 7).


3
7

CONTROL GROUP, 70 MODERATE ALCOHOL GROUP 70 - HIGH ALCOHOL GROUP

STIMULUS: 5*/ SEC? DECELERATION
3-SEC LIGHT GROUP.

PRE =@—@

Post 1 O—O

Post 1 4——&

2
ie}

a
3

as
i}

iy

8

10 ‘

LIGHTS ON LIGHTS ON x
T \\ - ‘ =
jolts lub gobi

SLOW PHASE NYSTAGMUS (DEGREES PER 3-SEC INTERVAL)

9 18 27 36 45 54 63 72 9 18 27 36 45 54 63 72 8 90 9 18 27 36 45 54 63 72 BI 90
TIME IN SECONDS

Fievre 17. Response data for the average number of degrees of slow phase eye movement resulting from the 12-
sec deceleration of 5°/sec*. Immediately following the end of the deceleration, the room lights were turned on
for 3 see, during which time the subject fixated on a target. he short bar above the zero line represents the
period of room illumination while the arrow indicates the end of the stimulus. Points plotted above the zero
line represent the primary response, while those below represent the secondary response. [re refers to the
response obtained prior to the ingestion of alcohol, while Post I and Post IT refer, respectively, to data ob-
tained 45 min and four hours after ingestion. The values are plotted in 3-sec intervals; each point represents
the average response of five subjects.

20


Ficure 21. A portion of the nystagmic tracings for a subject’s r

STIMULI: SEC? FOR 12 SEC

ACCELERATION

ANN
af oat fh Ne ita Ka RA,

ane a

DECELERATION
TM ow nN
wf ye UE! NAA
roa UGHTS ON

5 uy AS n N rn nN

Na N\A NN a Ko ae
SUBJECT CT

sponse to the dark acceleration and to the de-
: period of illumination. The stimuli were comparable: a 12-sec acceleration and a
the rate of 5°/sec*, Although the nystagmic responses are in opposite directions
the response characteristics should be similar. Differences in primary or secondary nystagmus may be at-
tributed to the effects of visual fixation during the interval of light. The dark horizontal bar indicates the
period of room illumination, while the vertical bars demarcate the stimulus interval. Calibrations (15° of
eye movement) appear before each of the trials, The arrow indicates the point at which the primary nys-
tagmus ends. ‘The effects of visual fixation are evident in the shortened primary nystagmus and the enhanced
secondary nystagmus depicted in the lower set of tracings.

celeration with the &8-s
12-see deceleration each

26


Ficure 1. Modified Stille-Werner RS-3 chair used to administer the rotatory stimuli. The head rest and bite
board were used to restrict the subjects’ head movements and to keep the horizontal canals in the plane of
rotation. The cross-shaped device at the front of the rotator contains the calibration lights. With the doors
closed and the canopy down, all breeze cues are eliminated. A hole in the canopy permits voice communication
with the control room via the microphone suspended above the subject’s head.

2


3
—
3

1

9 oF ar ‘STIMULUS: BRAKE DECELERATION
MENTAL ARITHMETIC

PRE

8 Bb er Post1 O-0
Post aa

x

o

o

s

ow

x

MODERATE
1 atconou.
Group

NUMBER OF NYSTAGMIC EYE MOVEMENTS PER 3-SEC INTERVAL

Loteeteatit Lestat 4 ita
& 18 27 36 45 54 63 72 81 90 99108 IIT 126135 9 18 27 36 45 54 63 72 B90 9 18 27 36 45 54 63 72 BI

TIME IN SECONDS

Froure 10. Response data for the average number of nystagmic eye movements resulting from the brake decelera-
tions under the Mental Arithmetic condition. Symbols and markings are identical to those used in Figure 3.

or 20 20
[ —stimu.us: eraxe oeceLenarion
KEY PRESS
PRE
~ Post 1 o—o
7h 70 roha-«
z op at Post aa—me
$ ‘
z
&
¢
2 ool col.
§
*
£ SOP CONTROL GROUP Sot HIGH ALCOHOL GROUP
ra
Fa
$< 40
®
$
3 Bo 30F
=
b
Z
2
= ob L
g
z
=
ze rok
a

9 8 27 36 45 34 63 72 8 90 99 100 UT
TIME IN SECONDS

345 ee

Figure 11. Response data for the average number of degrees of slow phase nystagmus resulting from the brake
decelerations under the Key Press condition. Symbols and markings are identical to those used in Figure 3.

13


PRE ALCOHOL

ell a ee

POST ALCOHOL
15° fi fe er ;
\ a Core nas

CW STIMULUS: 5°/SEC2 ACCELERATION FOR I2 SEC SUBJECT IN DARKNESS FIXATED ON
TARGET LIGHT.

Froune 18. A portion of the tracings of the nystagmic response of a subject to a 12-see acceleration of 5°/sec?
during visual fixation of a dimly lit target-light. The vertical bars indicate the beginning and end of the
stimulus. The calibration, representing 15° of eye movement, appears before each trial. ‘The subject's response
was recorded before and 45 min after the ingestion of 2 ml of 100-proof vodka per kg of body weight. The
effect of alcohol on the visual fixation system is evident in the relatively strong nystagmic response for the
Post condition. Visual fixation, while under alcohol intoxication, is much less effective in suppressing the nys-
tagmic response to vestibular stimulation.

PRE ALCOHOL

POST ALCOHOL

fre

4

i waa
15° ok mend WAV A stadia, “aden, frieannonnescnn eaten

STIMULUS: BRAKE DECELERATION FROM CW ROTATION
SUBJECT FIXATED ON TARGET WITH ROOM LIGHTS ON.

Ficurr 14. A portion of the tracings of the nystagmic response of a subject to a brake deceleration, following
two min of constant velocity at 60°/sec. The vertical bar indicates the start of the deceleration and the
point where the room lights were turned on. The subject was instructed to fixate on the target-light as soon
as the room lights came on, A calibration representing 15° of eye movement appears before each trial. Changes
in the response under alcohol are similar to those noted in Figure 13.

15


ALCOHOL AND DISORIENTATION-RELATED RESPONSES.
Il. NYSTAGMUS AND “VERTIGO” DURING ANGULAR ACCELERATION

The integrity of the visual and vestibular
systems is important in the maintenance of
orientation during flight. Although alcohol is
known to affect the vestibular system through
the development of a positional alcohol nystag-
mus, information concerning the effects of aleohol
on “vertigo” and eye-movement (nystagmus)
responses to angular acceleration is contradictory.
Although Barany' noted no change in the dura-
tion of the nystagmic response following alcohol
ingestion, he reported that the subjective sensa-
tions were weakened. Manz** found a prolonged
duration of post-rotatory nystagmus, and later
studies by Taschen** **, Schweitzer®*, and Schulte
and Roth? all indicated that the nystagmic re-
sponse was enhanced following alcohol ingestion.

Contrary to the preceding results, Forster’?
reported that alcohol depressed the nystagmic
response to rotatory stimulation. Subsequent
studies by Bochenek and Ormerod, Mizoi, Ishido,
and Ohga**, Ey, and Di Guinta and Rosa‘?
supported the view that alcohol exerts a suppres-
sive effect on nystagmus.

These differences in reported results might be
attributed in part to the presence or absence of
visual stimuli. The studies showing suppression
were notably lacking in visual stimuli, while
those studies reporting enhancement or no change
included visual stimuli. An additional factor
which may have influenced the findings concerns
the effects of alertness on the nystagmic response.
Studies by Collins**® have shown that variations

Data presented here were submitted to the Psychology
Department, University of Oklahoma, in partial fulfill-
ment of the requirements for the degree of Doctor of
Philosophy under the guidance of Dr. William E. Collins.
The assistance of Gail Kranz, Ruth Ann Mertens,
Cynthia Cochran, Carlyn Manley, and Nancy Rice in
the conduct of the study, of Dr. Earl Folk and Mrs.
Rosalie Melton for some of the statistical analyses, and
of Dr. Delbert Lacefield and Mrs. Pat Roberts in the
collection and analysis of the blood samples, is grate-
fully acknowledged.

in alertness will alter the nystagmic responses to
rotatory stimulation and that these variations
can be manipulated by appropriate instructions.
Under “alert” conditions the nystagmic response
is of higher amplitude and of longer duration
than that obtained when the subject is relaxed
and in a “reverie” state.

The present study was designed to investigate
the influence of alcohol on the subjective and
nystagmic responses to rotatory stimulation:
(a) with and without visual fixation, and (b)
with the alertness of the subjects controlled by
instructions. Additional information was ob-
tained concerning the effect of alcohol on a pro-
posed relationship between the duration of the
rotation-induced turning experience and the
duration of the spiral aftereffect.2"~°

I. Method.

A. Subjects. Subjects were 30 male college
students with no previous laboratory experience
involving vestibular stimulation. They ranged
from 21 to 30 years of age and were randomly
placed in three groups of ten each. Of the three
groups, one was designated as “high alcohol,”
one as “moderate alcohol,” and the other served
asa control group with no alcohol.

B. Apparatus. The acceleratory stimuli were
provided by a Stille-Werner RS-3 rotation de-
vice located in a light-proof room. The RS-3
chair was modified by an enclosure (see Figure
1) which obviated any breeze cues to motion and
was fitted with a head rest and bite-board to
prevent head movements.

An eight-inch spiral, attached to a variable
speed motor, provided the stimuli for the spiral
afteretfect (SAE). The device was located seven
feet in front of the subject in a well-lighted
laboratory room, The speed of rotation was 80
rpm and the stimulus duration was 15 seconds.


TIME IN SECONDS

Z sor CONTROL GROUP 607 MODERATE ALCOHOL GROUP 60 /- HIGH ALCOHOL GROUP
ze L L 4 STIMULUS:
ivy) 1 5*/SEC? DECELERATION
5 sob 50+ Eo) nn 8-SEC LIGHT GROUP
o bf f L | 3 PRE
Ww PosT I O——O
® aoh ao ao PosTO A-—A&
m
ef L L
ws
Q 3b 30- 30-
n
wo b L
Ww
& 20f- 20+ 20k
Ww
a - b L
Biot toh tok
aL i L
z LIGHTS ON \ UGHTS ON 4) LIGHTS ON
o o— 4 —
ead a
2b , iN L x
w \
q “10h “0b el
a bt =
7 tht tt, thay rh ty
20) 20 120
a 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI 9 18 27 36 45 54 63 72 BI

Ficure 19. Response data for the average number of degrees of slow phase eye movement resulting from the 12-
sec deceleration of 5°/sec*. The room lights were turned on at the start of the deceleration and remained on

for 8 sec.

Symbols and markings are identical to those used in Figure 17.

24




REFERENCES

R.: Experimentelle Alkoholintoxication.
MONATSCHRIF’ PUR OHRENKEILKUNDE UND
LARYNGO-RHINOLOGIE, 45 :959-961, 1911.

. Bekésy, G.: Subjective cupulometry. ARCHIVES
OF OTOLARYNGOLOGY, 61:16-28, 19:

;. Bochenek, % and F, C. Ormerod: The inhibitory
action of certain substances on the response to
vestibular stimulation. JOURNAL OF LARYNGOL-
OGY AND O'TOLOG 30-44, 1962.

w

Po

4. Bodin, M. A.: Some practical notes for the analysis
of post-rotational nystagnms by determination of
time constants of decays, Unpublished manuscript,
1966.

5. Collins, W. E.: Effects of mental set upon vestibular
nystagmus. JOURNAL OF
CHOLOGY, 63:191-197, 1962,

6. Collins, W. Manipulation of arousal and its
effects upon human vestibular nystagmus induced
by caloric irrigation and angular accelerations.
AEROSPACE MEDICINE, 34:124-129, 1963.

7, Collins, W. B.: Modification of vestibular nystagmus

and “vertig by means of visual stimulation.
TRANSACTIONS OF THE AMERICAN ACADEMY
OF OPHTHALMOLOGY AND OTOLARYNGOL-
OGY, 72:962-979, 1968.

8. Collins, W. Special effects of brief periods of
visual fixation on nystagmus and sensations of
turning. AEROSPACE MEDICL 266,
1968,

9. Collins, W. E.: Task-control of arousal and the
effects of repeated unidirectional angular accelera-
tion on human vestibular responses. ACTA OTO-
LARYNGOLOGICA SUPPLEMENTUM, 190, 1064.

10. DiGiunta, E. and D, Rosa: Rilievi nistagmograficl
post-rotatorii in corso di intossicazione alcoolica
acuta, CLINICA  OTO-RINO-LARINGOIATRICA
(ROMA), 20:88-105, 1968.

11. By, W.: Storungen des oculo-yestibularen Systems
bei alcoholisierten Personen. BERIGHT: DEUTSCH
OPHTHALMOLOGISCHE GESSELSCHAFT, 65:

349. , 1964.

12. Forster, B.: Hlektronystagmographische Untersuch-
ungen uber den Drehbeschleunigungs-nystagmus
nach Alkoholgaben, DEUTSCHE ZEITSCHRIFT
FUR DIE @ ITE GERICHTLICHE MEDIZIN,

E. and L. 8. Lauver: Vestibular reactions

during prolonged constant angular releration.

JOURNAL OF APPLIED PHYSIOLOGY, 16:215—

20, 1961

14. Jatho, K.: Die Wirkung der Alkoholintoxication auf
den Vestibularapparant unter besonderer Beruck-

sichtigung der Storungen der vestibular-okulomotor-
ischen Regelfunktion, II, Mitteilung Ergebnisse
experimenteller Untersuchungen, — ZEITSCHRIFT
FUR LARYNGOLOGIE, RHINOLOGIE, OTOLOGIE
UND THRE GRENZGEBLETE, 44:105-108, 1965.

15. Manz, Rudolf: Der Einfluss geringer Alkoholgaben
auf Teilfunktionen yon Auge and Ohr. DEUTSCHE
ZEITSCHRIFT FUR DIE GESAMTE GERICHT-

LICHE MEDIZIN, 32 :301-812, 1940.

Mizoi, Y., 'T. Ishido, and N, Ohga: Studies on post-

yotatory nystagmus in alcohol intoxication, JAPA-

E JOURNAL OF LEGAL MEDICINE, 16:247~
260, 1962.

17. Nilsson, A, and N. G. Henriksson: 'The oculogyral
iMusion—a form of rotation after-effect—and its
relation to the spiral after-effect in repeated trials.
PSYCHOLOGICAL RESEARCH BULLETIN, 7:1-
17, 1967.

18. Reason, J. T.
ness
ity”

: Individual differences in motion sick-
‘: A further test of the “receptiv-

BRITISH JOURNAL OF PSY-
CHOLOGY, 60:321-328, 1969.

19. Reason, J. T.: Relations between motion sickness
susceptibility, the spiral after-effect and loudness
estimation, BRUPISH JOURNAL OF PSYCHOL-
oy, 393, 1968.

20. Reason, J. T. and A. J. Benson: Individual differ-
ences in the reported persistence of visual and
labyrinthine after-sensations, and of exponentially
decaying visual and auditory signals, BRITISH
JOURNAL OF PSYCHOLOGY, 59:167-172, 1968,

24. Schroeder, D. J.: Alcohol and Disorientation-Related
Respons I agmus and Vertigo During
Caloric 1 Optokinetie Stimulation. FAA OAM

report 71-6, 1971.
Schulte, K. and H. Roth: Drehnys
kohol-konzentration,

agnius un Blutal-
ZENTRALBLATT FUER
yERTEHRS—PSYCHOLO-
GEBIETE (Alfred/

Leino, Germany),

3. Schweitzer, H.: Gri

phologische, klinische und psy-
Untersuchungen unter Alkoholwirkung.

sche

NDHEITSDIENST  (Stutt-
24, Nystagmusprufungen zur Verstellung
der Alkoholbeeinthussung. DEUTSCHE  ZEIT-

SCHRIFT FUR DIE GESAMTE GERICHTLICHE

1956.

B.: Eine einfache Nystagmusprobe zur
extsellung der Alkoholbeeinfiussung, MEDIZIN-
MONATSSCHRIFT (Stuttgart),

27


ll eee

Tasue 7.—Results of the Paired t Tests for the Pre vs. Post I and Pre vs. Post II Comparisons of the Nystagmic Re-
sponses of the Control Group to the Rotatory Stimuli.

Condition
Measure Comparison Mental Arithmetic Key Press Reverie
Ace Dee Ace Dee Ace
Displacement Pre vs. Post I 3.45** 1.07 1.16 0.92 0.9%
Pre vs. Post II 3.940% 1.15 2.06 0.92 0.68
Frequency Pre vs. Post I 0.81 2.08 2.12 0.83 0.85
Pre vs. Post IT 0.15 0.79 0.66 1.27 0.13
Duration Pre vs. Post I 0.26 0.78 0.64 0.82 0.44
Pre vs. Post IT 0.62 0.48 1.34 1.17 0.88
Velocity Pre vs. Post I 0.32 1.83 2. 60* 0.64 1.21
Pre vs. Post II 0.05 1.79 0.24 1.36 0.71
*p <.05
**D <.01

The Pre-to-Post I declines in nystagmus for velocity” measures for the brake decelerations,
the moderate alcohol group were larger than all of the changes in slow phase displacement,
those noted for the control group. All of the — frequency, peak velocity, and duration were sta-
significant declines resulting from the accelera-  tistically significant (.05-.001 levels), Even

tions (.05-.001 levels) occurred for the frequency though there was considerable recovery at the

and duration measures in Table 8. The Post II Post II testing session, most of the frequency

values were very near the Pre levels. and duration scores were still significantly below
The suppressive effect of alcohol was most their Pre levels (Table 9).

evident in the responses of the high alcohol Thus, alcohol ingestion suppresses the nystag-

roup. With the exception of two of the “peak mic response to angular stimuli when the re-
g Pt pe P

Tanie 8.—Results of the Paired t Tests for the Pre vs. Post I and Pre vs. Post II Comparisons of the Nystagmic
Responses of the Moderate Alcohol Group to the Rotatory Stimuli.

Condition
Measure Comparison Mental Arithmetic Key Press Reverie
Ace Dee Ace Dec Ace
Displacement Pre vs. Post I 1.12 1,28 0.31 0.27 1,80
Pre vs. Post II 1.60 0. 57 1,70 1.35 0. 89
Frequency Pre vs. Post I 3.40% 4.120% 2.75" 1.91 2.11
Pre vs. Post II 0.44 0.75 0.16 0,57 0.45
Duration Pre vs. Post I 2.79% 3.69** 3, 96** 4, 89% 3.57%"
Pre vs. Post IT 0,94 1,93 1.04 1.90 1.01
Velocity Pre vs. Post I 0.07 0.93 0.76 2.33* 0.21
Pre vs. Post IT 0.90 0.08 2.71" 3. 18* 1.78
*p <.05
**D <.01
er D <.001

1


oh or or ‘STIMULUS: BRAKE DECELERATION
fi t KEY PRESS
z A I\ PRE OO
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9 18 27 36 45 54 63 72 BI 90 99 108 II7 9 18 27 36 4554 63 9 18 27 36 45 54 63 72 BI

TIME IN SECONDS

Ficure 12. Response data for the average number of ny:
Symbols and markings are identical to those used in Figure 3.

tions under the Key Press condition.

various stimuli (Figures 3 through 8) and in
the nystagmus tracings presented in Figure 2.

Changes in the nystagmic responses from the
brake decelerations, following alcohol ingestion,
were similar to those noted for the accelerations
(Tables 2 through 5 and Figures 9 through 12).

These data support the earlier studies* #116
which showed that alcohol ingestion suppressed
the nystagmic response to rotatory stimuli. How-
ever, these results fail to support other investiga-
tions*? #2425 where alcohol enhanced vestibular
nystagmus.

D. Resolution of Conflicting Results from Pre-
vious Studies. Data from seven additional sub-
jects who received rotatory stimulation while
fixating on visual targets provide a basis for re-
solving conflicting reports in the literature. Trac-
ings from a subject’s nystagmic response to the
acceleration while fixating on the target lights
in an otherwise dark room, and from the brake
decelerations while fixating on the target with
the room lights on, are presented in Figures 13
and 14. It is apparent from both figures that
the subject was able to suppress the recorded

‘stagmic eye movements resulting from the brake decelera-

nystagmic response by visual fixation when al-
cohol was not involved. However, following the
ingestion of alcohol, a low-amplitude, high-fre-
quency nystagmus was elicited by both stimulus
rates.

What was reported in several previous studies
as an enhanced vestibular response to acceleratory
stimuli following the ingestion of alcohol can
now be explained by the interference of alcohol
with the subject's ability to maintain visual fixa-
tion. The inability to fixate permits a more
vigorous nystagmic response to manifest. itself.
This interference by alcohol was also apparent
in the subjects’ reports concerning their attempts
to fixate; greater effort and more time was re-
quired to bring the target into focus under the
alcohol condition. (Similar effects have been
obtained using caloric vestibular stimulation.)?*
Data from a study by JathoTM offer additional
support to this view that alcohol interferes with
the visual fixation mechanism. JathoTM reported
that recovery movements of the eyes following
head shaking took a considerably longer time
after the ingestion of alcohol.

14