Available online at:
https://cc.arcabc.ca/islandora/object/cc%3Apsycjournal

J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.
Submitted Fall 2021; accepted June 2022.

What Are the Biological Mechanisms of ObsessiveCompulsive Disorders (OCD)?
Authors: Leanne Wong* and Clara Valente
Supervising Instructor: Michael Pollock, Psyc 215 (“Biological Psychology”)
Department of Psychology, Camosun College, 3100 Foul Bay Road, Victoria, BC, Canada V8P 5J2
*Corresponding author email: Leanne.M.Britton@gmail.com

ABSTRACT
In this paper, we sought to understand what are the biological mechanisms of ObsessiveCompulsive Disorders so that we could learn how to be aware of our obsessive-compulsive
tendencies. Previous research has found that obsessive-compulsive disorder correlates with brain
dysfunctions such as with frontal-parietal communication, brain activity in the right frontal pole,
and levels of dopamine. In our first (correlational) study, we tested the strength of these
relationships by examining naturalistic daily changes in their variables longitudinally over a oneweek period. We measured parietal cortex functioning by performance in the Spatial Cueing
Task, frontal cortex functioning by performance in the Berg’s Card Sorting Test, levels of
dopamine by number of eye blinks in one minute, and OCD by number of obsessive thoughts
and compulsive behaviour in a day. Based on the strength of correlation found between parietal
cortex functioning and levels of OCD symptoms in our correlational study, we then conducted a
second (experimental) study to test for a causal relationship between these two variables. Over a
one-week period, we randomly assigned participants each day to either a high parietal cortex
functioning experimental condition or a low parietal cortex functioning control condition and
measured the effect this manipulation had upon the levels of OCD symptoms. Data pooled across
participants in our correlational study showed significant correlations of levels of OCD
symptoms with parietal cortex functioning, but not with frontal cortex functioning or with levels
of dopamine. However, the results of our experimental study failed to establish a causal role of
the parietal cortex functioning upon levels of OCD symptoms. Therefore, the influences of
specific brain structures and neurotransmitters on levels of OCD symptoms remains uncertain.
1. Introduction
1.1 Research Problem
Obsessive-Compulsive Disorder (OCD)
causes personal suffering that hinders one to
thoroughly enjoy life. Having obsessivecompulsive tendencies drains one’s energy
level and occupies one’s mind in an
unhealthy way. It triggers intrusive thoughts,

irrational beliefs, and an excessive reliance
on unproductive behaviours. As individuals
who struggle with symptoms of obsessivecompulsive disorder and have family
members who also face this condition, we
would like to understand the physiological
processes of this disorder in order to better
cope with it and not be prisoners to our
perfectionism.
223

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

1.2 Literature Review
One factor previously found to correlate
with OCD is a deficient frontal-parietal
communication. For example, in an
experimental study by Liu et al. (2021), the
researchers measured the brains’ restingstate Functional Connectivity (rsFC) and
Effective Connectivity (rsEC) of a group of
unmedicated individuals diagnosed with
OCD and a healthy control group through
fMRI and MRI scans. They found that the
interconnection between the frontal-parietal
cortex and both the basal ganglia and the
cerebellum was weaker in the OCD group
than in the health control group. Based on
these results, the researchers suggested that
individuals with OCD have an impaired
frontal-parietal interconnectivity.
Another factor previously found to
correlate with OCD is increased activity in
the right frontal pole. For example, in a
study by Bohon et al. (2020), the Wisconsin
Card Sorting Test (WCST) was utilized on
the participants to measure perseverative
errors in OCD participants. The participants
were given instructions to match the cards to
a certain rule that they were not informed
about. However, through feedback,
participants were able to figure out the
sorting rule. Throughout the experiment
researchers would change the rule without
the participants knowing and again the
participants would have to figure out the
new sorting rule based on their feedback.
The OCD participants showed increased
activity in the brains’ right frontal pole and
increased perseverative errors, when
compared to the healthy control group.
Based on these results, the researchers
suggested that mental skill tasks, such as the
WCST, trigger more intense frontal brain
activity in OCD participants.
A third factor previously found to
correlate with OCD is increased levels of

dopamine. For example, in a study by Viol
et al. (2020), venipuncture produced an
increase in dopamine levels in patients that
met DSM-IV criteria for OCD after they
underwent psychotherapy. Based on these
results, the researchers suggested that,
through psychotherapy treatment, increases
in dopamine levels result in reduced OCD
symptoms.
1.3 Hypotheses
Based on the above literature review, we
predicted the following hypotheses:
Hypothesis #1: If parietal cortex functioning
decreases then OCD symptoms will
increase.
Hypothesis #2: If frontal cortex functioning
decreases then OCD symptoms will
increase.
Hypothesis #3: If dopamine levels increase
then symptoms of OCD will decrease.
2. Methods
2.1 Participants
The two authors of this paper served as
the participants in its studies. The
participants ranged in age from twenty-one
to thirty-three years old, with an average age
of twenty-seven years, and included two
cisgender females. The participants were all
undergraduate students at Camosun College
who completed the current studies as an
assignment for Psych 215 (“Biological
Psychology”) and were grouped together
due to their mutual interest in OCD.
2.2 Correlational Study Methods
We first performed a correlational study
to test concurrently all of our hypotheses by
examining naturalistic daily changes in their
variables longitudinally. Each participant
kept a study journal with them at all times
224

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

over this study’s one-week period in order to
record self-observations of the following
four variables: (1) parietal cortex
functioning, (2) frontal cortex functioning,
(3) levels of dopamine, and (4) levels of
OCD symptoms.
2.2.1 Parietal Cortex Functioning
To measure parietal cortex functioning,
each participant did the Spatial Cueing Task
every morning during the one-week study
period. The Spatial Cueing Task was
accessed in the “Psych Lab 101” app
(https://www.neurobs.com/menu_presentati
on/menu_teaching/psych_lab_101).
2.2.2 Frontal Cortex Functioning
To measure frontal cortex functioning,
each participant took the Berg’s Card
Sorting Task test each day first thing in the
morning during the one-week study period.
The Berg’s Card Sorting Task test was was
accessed in the “Psych Lab 101” app
(https://www.neurobs.com/menu_presentati
on/menu_teaching/psych_lab_101).
2.2.3 Levels of Dopamine
To measure levels of dopamine, each
participant measured how many times they
blinked in one minute each day first thing in
the morning during the one-week study
period.
2.2.4 Levels of OCD Symptoms
To measure the levels of OCD symptoms,
each participant recorded in a study journal
the number of times they had obsessive
thoughts and compulsive behaviours, and
the types of obsessive thoughts and
compulsive behaviours they experienced
each day. We considered the types of
obsessive thoughts to be every repetitive,
irrational, and/or intrusive thoughts we
would have, and the types of compulsive
behaviours to be every ritualized behaviour
we performed, such as dysfunctional
cleaning, counting, rearranging, planning,
and others. This process had to be completed
in all seven days of the experiment.

2.3 Correlational Study Planned Analyses
To assess the strength and statistical
significance of associations between
variables predicted by our three hypotheses,
we performed Pearson product moment
correlations of their predictor variables
(performance in the Spatial Cueing Test and
Berg’s Card Sorting Task, and eye blink
counts) with their outcome variable (the
amounts of times participants experience
obsessive thoughts and compulsive
behaviours in a day). For testing Hypothesis
#1, we correlated each day’s performance in
the Spatial Cueing Task with that
participant’s observations of the number of
obsessive thoughts and compulsive
behaviours on that day. For testing
Hypothesis #2, we correlated each day’s
performance in the Berg’s Card Sorting
Task with that participant’s observations of
the number of obsessive thoughts and
compulsive behaviours on that day. For
testing Hypothesis #3, we correlated the
number of eye blinks in a minute every
morning with that participant’s observation
of the number of obsessive thoughts and
compulsive behaviours on that day. We
performed all of the above correlations
separately for each participant as well as
using data pooled across all of the
participants. For the correlations using
pooled data, in addition to using the raw
data, we also performed correlations after
we had first transformed the data from each
participant into z-scores in order to
standardize differences in averages and
variability seen between the participants in
their data and thus make them more
comparable. A correlation coefficient was
considered statistically significant if the
probability of its random occurrence (p) was
< .05 (i.e., less than 5% of the time expected
by chance alone).
225

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

2.4 Experimental Study Methods
Based on the strength of the correlation
between parietal cortex functioning and
levels of OCD symptoms found in our
correlational study, we then chose to
conduct an experimental study to test for a
causal relationship between these two
variables from Hypothesis #1.
We manipulated the independent
variable, parietal cortex functioning, over a
one-week period by randomly assigning through flipping a coin - participants each
day to either a high parietal cortex
functioning experimental condition or a low
parietal cortex functioning control condition
using a blind procedure. On the high parietal
cortex functioning experimental condition
days, participants took the Spatial Cueing
Task first thing in the morning, as
previously described above in the
Correlational Study Materials and
Procedures. The duration of the test was
approximately 5 minutes to complete. On
the low parietal cortex functioning control
condition days, participants followed their
regular routine without taking the Spatial
Cueing Task. In both conditions, the levels
of OCD symptoms of the participants was
measured on a obsessive-compulsive
symptoms scale ranging from 0 to 10, with 0
describing neither obsessive thoughts, nor
compulsive behaviours in one day, 5, as
moderate obsessive thoughts and
compulsive behaviours in one day, and 10,
as numerous obsessive thoughts and
compulsive behaviours in one day.
While it was impossible for participants
to be unaware of what condition they were
receiving and thus maintain a double-blind
procedure, to help reduce bias in
measurements each participant had a family
member or roommate act as an assistant to
measure the levels of OCD symptoms the
participants presented during each day of the
one-week period of experimentation. The

participants did not disclose with the
assistants whether they had taken the Task
during the day. The order of conditions was
randomly assigned each day. The dependent
variable, levels of OCD symptoms, was then
measured by the assistants on both
experimental and control day at night using
the same obsessive-compulsive symptoms
scale described above in the correlational
study.
2.5 Experimental Study Planned Analyses
To assess the statistical significance of
differences seen in levels of OCD symptoms
on the high parietal cortex functioning
experimental days vs. the low parietal cortex
functioning control days, Student’s t-tests
were performed. We performed t-tests
separately for each participant as well as
using data pooled across all of the
participants. For the t-tests using pooled
data, in addition to using the raw data, we
also performed t-tests after we had first
transformed the data from each participant
into z-scores in order to standardize
differences in averages and variability seen
between the participants in their data and
thus make them more comparable. An
average difference between conditions was
considered statistically significant if, using a
one-tailed distribution (i.e., to determine if
there is a difference between groups in a
specific direction), the probability of its
random occurrence (p) was < .05 (i.e., less
than 5% of the time expected by chance
alone).
3. Results
3.1 Correlational Study Results
As shown in Table 1, parietal cortex
function was significantly correlated with
levels of OCD symptoms; however, our
predicted direction of relationship between
226

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

the variables - that decreased parietal cortex
functioning would increase OCD symptoms
- , was not confirmed. Although not being
statistically significant for both participants
(for one, r = .56 and p = .20, and for the
other, r = .93 and p = .0009), frequency of
OCD symptoms was significantly positively
correlated with parietal cortex functioning
using both pooled raw data (r = .67, p =
.006; see Figure 3) and pooled standardized
data (r = .74, p = .001; see Figure 4). In
contrast, no statistically significant
correlations were not found between levels
of dopamine using both participant’s data
(for one, r = -.16 and p = .74, and for the
other, r = .98 and p = 1.42E-06), pooled raw
data (r = .24, p = .41; see Figure 1), or
pooled standardized data (for levels of
dopamine, r = .41, p = .14; see Figure 2).
Similarly, frontal cortex functioning and
frequency of OCD symptoms were not
significantly correlated using any single
participant’s data (all r ≤ .69, all p ≥ .08),
pooled raw data (r = .23, p = .44, see Figure
5), or pooled standardized data (r = .49, p =
.07, see Figure 6). Based on a comparison of
the correlation coefficients using either the
pooled raw data or the pooled standardized
data, parietal cortex functioning showed the
strongest correlation with frequency of OCD
symptoms.

Figure 9), or pooled standardized data (p =
.35; see Figure 8), (p = .23, see Figure 10).
4. Discussion
4.1 Summary of Results
Based on previous research, we
hypothesized that decreases in parietal
cortex functioning (Hypothesis #1),
decreases in frontal cortex functioning
(Hypothesis #2), and decreases in levels of
dopamine (Hypothesis #3) would be
followed by increases in OCD symptoms.
Data pooled across participants in our
correlational study showed a significant
correlation between parietal cortex
functioning and levels of OCD symptoms;
however, it did not support the predicted
direction of relationship between increased
OCD symptoms and decreased parietal
cortex functioning (Hypothesis #1).
Additionally, the data of our correlational
study did not show a significant correlation
between levels of OCD symptoms and
frontal cortex functioning (Hypothesis #2),
or between levels of OCD symptoms and
levels of dopamine (Hypothesis #3). And
finally, the results of our experimental study
were not able to establish a causal role of the
parietal cortex functioning upon levels of
OCD symptoms.

3.2 Experimental Study Results
4.2 Relation of Results to Past Research
As shown in Table 2 & 3, no significant
differences were found in levels of OCD
symptoms between the high parietal cortex
functioning experimental condition (Spatial
Cueing Task) and low parietal cortex
functioning control condition. Statistically
significant differences between these
conditions were not seen using any single
participant’s data (all p ≥ .15), pooled raw
data (p = .23; see Figure 7), (p = .35; see

The strong relationship in our
correlational study between OCD symptoms
and parietal cortex functioning is in line with
previous research; however, the direction of
the variables found in our study is the
opposite of the direction found in past
studies, with increased parietal cortex
functioning being associated with decreased
levels of OCD symptoms. Liu et al. (2021)
found that the interconnection between the
227

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

frontal-parietal cortex and both the basal
ganglia and the cerebellum was weaker in
their OCD group than in the health control
group. Based on these results, the
researchers suggested that individuals with
OCD have an impaired frontal-parietal
interconnectivity. While Liu et al. (2021)
had two groups, participants that presented
OCD symptoms and a control group, and
utilized a fMRI scan to measure the wholebrain interconnectivity, in our correlational
and experimental studies we longitudinally
assessed parietal cortex functioning in two
college student who were not OCD patients
and measured/manipulated parietal cortex
functioning indirectly through recording the
average reaction time for the valid trial
condition of the Spatial Cueing Test.
Therefore, our measuring of the parietal
cortex functioning, rather than its
interconnectivity with other parts of the
brain, might have influenced the differences
in the results between our study and the
research by Liu et al. (2012). Furthermore,
taking the Spatial Cueing Task in our high
parietal cortex functioning experimental
condition might also have not been a strong
enough stimulator of the parietal cortex, as
the task takes a short period of time, and
moderate effort to be completed; thus it is
reasonable that taking the test in the
experimental condition and not taking it in
the control condition produced minimal
effects on levels of OCD symptoms. Finally,
having assistants with different levels of
proximity with the participants measure the
latter’s levels of OCD, basing their ratings
on subjective interpretations of the
behaviours of participants, could have also
influenced the lack of a causal relationship
found in the experimental study. In future
OCD studies, researchers should specifically
measure the interconnectivity between the
frontal and parietal cortex, as it was found to
be correlated with OCD symptoms, rather

than whole-brain connectivity, or the
activity of the cortexes separately.
The lack of a relationship between frontal
cortex activity and OCD symptoms found in
our correlational study differs from
previously published work. Bohon et al.
(2020) found that increased activity in the
brains’ right frontal pole and increased
perseverative errors were seen in OCD
participants when compared to a healthy
control group. Based on these results, the
researchers suggested that mental skill tasks,
such as the WCST, trigger more intense
frontal brain activity in OCD participants.
The methodology of our correlational study
differed from that of the Bohon et al. (2020)
study in two major ways that might account
for the discrepant results. First, a difference
between the studies is the number of other
tests completed within one study. While our
study used the Spatial Cueing Task, eye
blink test and the Berg’s Card Sorting Task,
Bohon et al. (2020) administered just the
WCST. Future studies could examine
whether the effects of the test order, in
which it was administered, could affect
frequency of OCD symptoms. Secondly, the
differences between the studies is the sample
size, which could have affected their
findings. Bohon et al. (2020) examined 14
adolescents with weighted restored Anorexia
Nervosa and 11 adolescents with OCD in
comparison to a healthy control group, while
our correlational study had only a small
sample size, being two participants, and a
restricted variety of sample groups. We
recommend that future studies test a larger
sample size and ensure the tests’ order is
controlled for.
Our correlational study failed to confirm
the relationship between frequency of OCD
symptoms and dopamine levels found by
previous research. Viol et al. (2020) found
that venipuncture increased dopamine levels
in patients that met DSM-IV criteria for
228

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

OCD to a greater extent after they had
underwent psychotherapy. Based on these
results, the researchers suggested that
through psychotherapy treatment, OCD
patients' dopamine levels increase. In
contrast, our participants did not find that
frequency of OCD symptoms affected
dopamine level. The methodology of our
correlational study differed from that of the
Viol et al. (2020) study in two major ways
that might account for the discrepant results.
First, there were differences between the
studies in how they measured dopamine
levels. Our correlational study relied only
upon self assessment. Future studies should
test whether the objectively verified aspects
of dopamine levels outlined by Viol et al.
(2020), but not subjective self assessment,
predict dopamine levels. Second, there
differences between the studies in when they
measured dopamine levels could affect their
findings. While Viol et al. (2020) examined
levels of dopamine in OCD participants
before versus after receiving psychotherapy,
while we measured natural fluctuations in
dopamine levels across days.
4.3 Implications of Results
Possible practical applications of our
current findings are that parietal cortex
functioning, frontal cortex activity and
dopamine levels are not responsible for
OCD symptoms. For instance, increased
parietal cortex functioning, decreased frontal
cortex activity and increased dopamine
levels did not result in decreased OCD
symptoms. We originally conducted the
current studies to find ways to reduce our
obsessive-compulsive tendencies based on
the knowledge of the biological mechanisms
of OCD. Unfortunately, due to the nonsignificant results from our correlation and
experimental studies, strategies to reduce

these tendencies cannot be offered. It
remains for future studies to determine all of
the biological mechanisms involved in
obsessive-compulsive disorders, and to
eventually create more objective methods to
measure OCD symptoms.
References
Bohon, C., Weinbach, N., & Lock, J. (2020).
Performance and brain activity during the
Wisconsin Card Sorting Test in
adolescents with obsessive–compulsive
disorder and adolescents with
weight‑restored anorexia nervosa.
European Child & Adolescent
Psychiatry, 29(1), 217–226.
https://doi.org/10.1007/s00787-01901350-4
Liu, W., Hua, M., Qin, J., Tang, Q., Han, Y.,
Tian, H., Lian, D., Zhang, Z., Wang, W.,
Wang, C., Chen, C., Jiang, D., Li, G.,
Lin, X., & Zhuo, C. (2021). Disrupted
pathways from frontal-parietal cortex to
basal ganglia and cerebellum in patients
with unmedicated obsessive compulsive
disorder as observed by whole-brain
resting-state effective connectivity
analysis – a small sample pilot study.
Brain Imaging & Behavior, 15(3), 1344–
1354. https://doiorg.libsecure.camosun.bc.ca:2443/10.100
7/s11682-020-00333-3
Viol, K., Schiepek, G., Kronbichler, M.,
Hartl, A., Grafetstätter, C., Strasser, P.,
Kastinger, A., Schöller, H., Reiter, E.-M.,
Said-Yürekli, S., Kronbichler, L.,
Kravanja-Spannberger, B., StögerSchmidinger, B., Hütt, M.-T., Aichhorn,
W., & Aas, B. (2020). Multi-level
assessment of obsessive-compulsive
disorder (OCD) reveals relations between
neural and neurochemical levels. BMC
Psychiatry, 20(1), 559. https://doiorg.libsecure.camosun.bc.ca:2443/10.118
6/s12888-020-02913-5
229

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Table 1
Correlations for Study Variables

Variables

Participant
#1

Participant
#2

Pooled raw
data

r

n

r

n

r

n

Pooled
standardized
data
r
n

-.16

7

.98*

7

.24

14

.41

14

.56

7

.93*

7

.67*

14

.74*

14

.29

7

.69

7

.23

14

.49

14

Levels of Dopamine
& Levels of OCD
Symptoms
Parietal Cortex
Functioning &
Levels of OCD
Symptoms
Frontal Cortex
Functioning &
Levels of OCD
Symptoms
* p < .05.

230

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Table 2
Descriptive Statistics for levels of OCD symptoms (measured by assistant) Across Different
Parietal Cortex Functioning Conditions

High Parietal

M

6.0

2.5

Pooled
raw
data
4.2

Cortex

SD

1.4

0.7

2.2

0.7

Functioning

n

2

2

4

4

Low Parietal

M

7.0

3.6

5.3

0.3

Cortex

SD

1.0

1.5

2.1

0.9

Functioning

n

3

3

6

6

Condition

Statistic

Participant Participant
#1
#2

Pooled
standardized
data
-0.5

Note. M, SD, and n, represent mean, standard deviation, and sample size, respectively. Levels of
OCD symptoms were measured by the experimenter on a 0-10 scale of amount of symptoms (0
= no symptoms to 10 = multiple symptoms).
* p < .05 for comparison of high parietal cortex functioning condition with its respective low
parietal cortex functioning condition.

231

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Table 3
Descriptive Statistics for levels of OCD symptoms (measured by experimenter) Across Different
Parietal Cortex Functioning Conditions

High Parietal

M

7.5

4.5

Pooled
raw
data
6.0

Cortex

SD

0.7

2.1

2.1

1.0

Functioning

n

2

2

4

4

Low Parietal

M

8.0

5.0

6.5

0.2

Cortex

SD

1.0

1.0

1.8

0.9

Functioning

n

3

3

6

6

Condition

Statistic

Participant Participant
#1
#2

Pooled
standardized
data
-0.2

Note. M, SD, and n, represent mean, standard deviation, and sample size, respectively. Levels of
OCD symptoms were measured by the experimenter on a 0-10 scale of amount of symptoms (0
= no symptoms to 10 = multiple symptoms).
* p < .05 for comparison of high parietal cortex functioning condition with its respective low
parietal cortex functioning condition.

232

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 1
Association Between Levels of Dopamine and Levels of OCD Symptoms Using Pooled Raw Data

233

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 2
Association Between Levels of Dopamine and Levels of OCD Symptoms Using Pooled
Standardized Data

234

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 3
Association Between Parietal Cortex Functioning and Levels of OCD Symptoms Using Pooled
Raw Data

235

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 4
Association Between Parietal Cortex Functioning and Levels of OCD Symptoms Using Pooled
Standardized Data

236

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 5
Association Between Frontal Cortex Functioning and Levels of OCD Symptoms Using Pooled
Raw Data

237

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 6
Association Between Frontal Cortex Functioning and Levels of OCD Symptoms Using Pooled
Standardized Data

238

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 7
Average Levels of OCD Symptoms (Measured By Assistant) Across Different Parietal Cortex
Functioning Conditions Using Pooled Raw Data

Notes. Levels of OCD symptoms scores are shown for high parietal cortex functioning and
low parietal cortex functioning conditions using pooled raw data from all participants. Errors
bars show ± 95% confidence levels. Overlapping scatterplot shows data from each
participant. Marker colour differentiates participants: red = participant #1, and orange =
participant #2.

239

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 8
Average OCD Symptoms (Measured By Assistant) Across Different Parietal Cortex Functioning
Conditions Using Pooled Standardized Data

Notes. Levels of OCD symptoms scores are shown for high parietal cortex functioning and low
parietal cortex functioning conditions using pooled standardized data from all participants.
Errors bars show ± 95% confidence levels. Overlapping scatterplot shows data from each
participant. Marker colour differentiates participants: red = participant #1, and orange =
participant #2.

240

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 9
Average Levels of OCD Symptoms (Measured By Experimenter) Across Different Parietal
Cortex Functioning Conditions Using Pooled Raw Data

Notes. Levels of OCD symptoms scores are shown for high parietal cortex functioning and
low parietal cortex functioning conditions using pooled raw data from all participants. Errors
bars show ± 95% confidence levels. Overlapping scatterplot shows data from each
participant. Marker colour differentiates participants: red = participant #1, and orange =
participant #2.

241

Wong & Valente - J Camosun Psyc Res. (2022). Vol. 4(1), pp. 223-242.

Figure 10
Average Levels of OCD Symptoms (Measured By Experimenter) Across Different Parietal
Cortex Functioning Conditions Using Pooled Standardized Data

Notes. Levels of OCD symptoms scores are shown for high parietal cortex functioning and low
parietal cortex functioning conditions using pooled standardized data from all participants.
Errors bars show ± 95% confidence levels. Overlapping scatterplot shows data from each
participant. Marker colour differentiates participants: red = participant #1, and orange =
participant #2.

242