Eye tracking and Attention Deficit Hyperactivity Disorder (ADHD): Can eye tracking identify the feigning of ADHD?
Dublin Core
Title
Eye tracking and Attention Deficit Hyperactivity Disorder (ADHD): Can eye tracking identify the feigning of ADHD?
Creator
Reva Maria George
Date
7/09/2022
Description
When diagnosing adult ADHD, it has proven difficult for clinicians to detect deceptive behaviour. Diagnosis of ADHD comes with economic, academic, and recreational benefits, which may account for the increasing feigning of the disorder. Current diagnostic methods: clinical interviews and self-report scales can be easily manipulated for a positive diagnosis. Hence the present study evaluated the utility of eye tracking devices to detect the feigning of ADHD. Eye movements of 38 participants (7 ADHD, 15 healthy controls, and 16 healthy feigners) were captured throughout the prosaccade and anti-saccade task. The performance of the participants on the task was evaluated in terms of latency and the percentage of error rate. The findings of the study reveal a significant difference in the latency of anti-saccade tasks i.e., feigners have an increased latency compared to healthy controls and ADHD participants. Because of the limited sample size, study findings cannot be generalized. Further investigations are needed with a much larger sample.
Subject
Eye-tracking, ADHD, Feigning, Prosaccade task, Anti-saccade task, latency, error rate, eye movements
Source
Method
Participants
Previous studies explaining feigning in ADHD acquired data from around 90-100 samples (Booksh et.al., 2010; Frazier et.al., 2008; Harrison et.al., 2007). The study therefore aimed to recruit 90 participants, 30 each in ADHD, healthy controls, and healthy feigners faking the disorder. Participants with and without a clinical diagnosis of ADHD were selected using the opportunity sampling method. A total of 42 participants between the age of 18-35 volunteered and were recruited for the study through the university disability service (11%), posters (16%) and through word of mouth (73%). Data of two participants were removed as the eye tracker repeatedly lost the pupil during recording. All participants were rewarded with an equal chance to win one of 6 £25 vouchers. Thirty-one of the 42 participants were healthy younger adult controls. Of the healthy control participants 15 (7 females; Mage = 24.33; SDage=4.32) participated as healthy controls, and the remaining 16 (9 females; Mage = 24.25; SDage=1.88) as healthy feigners. Seven ADHD participants (6 females) with a mean age 22.71 (SD=2.22) completed the study. The severity of the ADHD symptoms was analysed using the Adult ADHD self-report scale (for more demographic details see Table 1). The exclusion criteria include participants: 1) with any visual (other than corrected-to-normal vision) impairment 2) with any cognitive impairment 3) with additional diagnosis of neurological conditions 4) without a proper clinical diagnosis of ADHD. The exclusion criteria were applied because these impairments may interfere with the participants performance in the task.
Prior to data analysis, one of the participants was removed from ADHD group due to the lack of proper clinical diagnosis. Furthermore, a control participant was excluded with the assumption of having a probable mild cognitive impairment because the individual scored less than 82 (cut-off) in the Addenbrooke’s Cognitive Examination-III (ACE-III) (see Table 1 for further demographic details).
Participants
Previous studies explaining feigning in ADHD acquired data from around 90-100 samples (Booksh et.al., 2010; Frazier et.al., 2008; Harrison et.al., 2007). The study therefore aimed to recruit 90 participants, 30 each in ADHD, healthy controls, and healthy feigners faking the disorder. Participants with and without a clinical diagnosis of ADHD were selected using the opportunity sampling method. A total of 42 participants between the age of 18-35 volunteered and were recruited for the study through the university disability service (11%), posters (16%) and through word of mouth (73%). Data of two participants were removed as the eye tracker repeatedly lost the pupil during recording. All participants were rewarded with an equal chance to win one of 6 £25 vouchers. Thirty-one of the 42 participants were healthy younger adult controls. Of the healthy control participants 15 (7 females; Mage = 24.33; SDage=4.32) participated as healthy controls, and the remaining 16 (9 females; Mage = 24.25; SDage=1.88) as healthy feigners. Seven ADHD participants (6 females) with a mean age 22.71 (SD=2.22) completed the study. The severity of the ADHD symptoms was analysed using the Adult ADHD self-report scale (for more demographic details see Table 1). The exclusion criteria include participants: 1) with any visual (other than corrected-to-normal vision) impairment 2) with any cognitive impairment 3) with additional diagnosis of neurological conditions 4) without a proper clinical diagnosis of ADHD. The exclusion criteria were applied because these impairments may interfere with the participants performance in the task.
Prior to data analysis, one of the participants was removed from ADHD group due to the lack of proper clinical diagnosis. Furthermore, a control participant was excluded with the assumption of having a probable mild cognitive impairment because the individual scored less than 82 (cut-off) in the Addenbrooke’s Cognitive Examination-III (ACE-III)
Stimuli and Apparatus
Addenbrooke’s Cognitive Examination-III (ACE-III)
The ACE-III, developed by Hodges et.al, is an extended cognitive screening technique. The items of the test produce 5 sub-scores totalling 100, with each sub-score corresponding to a different cognitive domain, such as attention (18 points), memory (26 points), verbal fluency (14 points), language (26 points), and visuospatial skills (16 points) (Noone, 2015). Higher scores indicate superior cognitive functioning within the given domain. The validated cut-off point for normal cognitive functioning is 82/100, therefore individuals who yield a total score of < 82 are assumed to have probable mild cognitive impairment. The ACE-III has proven reliability (α= 0.88), sensitivity (0.93), specificity (1.0) and concurrent validity with alternative cognitive assessments such as the ACE-R (r= 0.99, p < 0.01; Hsieh, 2013).
Ishihara Colour blindness test
Ishihara colour blindness developed by Dr Shinobu Ishihara, was used to assess the colour vision deficiency of congenital origin, particularly red-green deficiency (Ishihara, 2011). It consists of 24 coloured plates containing a circle of dots with random colours and numbers. Each plate includes primary and secondary colour dots, with the primary colours appearing in patterns or numbers, while secondary colours appear as the background (Shaygannejad et.al., 2012). Plates 1–15 were utilised because of the fact that the main goal was to separate the colour defects from the normal colour appreciation simply. The participants were instructed to read out the numbers aloud, without more than three seconds' delay. A participant with an error in reading the numbers of two or more plates were considered to be having an impaired colour vision.
Royal Air Force (RAF) ruler
The RAF near point rule is a 50cm long square rule with a cheek rest and slider holding a revolving four-sided cube. One of the 4 sides has a vertical line with a central dot for convergence fixation. It is used for determining the near point of convergence (NPC) (Sharma, 2017). The participant is instructed to keep a direct gaze on the dot while the slider descends and to report when the dot's image breaks into two. The cut-off point for NPC break and NPC recovery is between 5 and 7 cm respectively (Pang et.al., 2010)
Adult ADHD Self Report Scale (ASRS-v1.1; Kessler et al., 2005)
The severity of ADHD symptoms presented by individuals with ADHD was assessed using the ASRS. The ASRS is an 18-item checklist, developed by the World Health Organization (WHO) work group together with the WHO World Mental Health (WMH) Survey Initiative (Kessler et al., 2005), to screen ADHD in adult patients. Completion of the ASRS requires participants to indicate how much they agree that the given statement relates to their behaviour over the past 6 months. The questions are divided into 2 parts: part A and part B. Part A contains 6 questions that are indicative of symptoms consistent with ADHD and are used for screening purposes. A score of 4 or above denotes symptoms typical with ADHD. The final 12 questions in Part B provide a more detailed breakdown of the specific symptoms an individual is presenting. The scale has high concurrent validity, and the internal consistency of the scale Cronbach’s α was found to be 0.88 (Adler et.al., 2006).
Hospital Anxiety and Depression Scale (HADS)
Hospital Anxiety and Depression Scale was developed by Zigmond and Snaith in 1983. It is a 14-item measure, used to detect the psychological distress of the participants (Zigmond & Snaith, 1983). Seven of the items measure anxiety (HADS-A), while the remaining seven measures the depressive symptoms (HADS-D). For each item, the participant is asked to indicate on a four-point scale the degree to which they feel a given statement relates to how they were feeling for the past week. The overall score for both anxiety and depression is 21. A score of 0-7 represents “normal”, 8-10 indicates “mild”, 11-14 “moderate and 15-21 indicates “severe” (Pais-Ribeiro et al., 2018). The scale is reliable and valid in measuring symptoms in both general and psychiatric patients (Bjelland et.al., 2002).
Eye-Tracking Measurement
Participants eye movements were recorded via the EyeLink Desktop 1000 at 500Hz. To minimize the head movements, a chin rest was used. Participants were seated approximately 55cm from the computer monitor (monitor run at 60 Hz). All the stimuli used for the study were created and controlled using Experiment Builder Software Version 1.10.1630. Two different computers are used for the eye-tracking system: a host PC which tracks the eye movements and determines their actual gaze positions and a display computer which shows the stimuli during the calibration and experimental trial.
Calibration
Prior to presenting the experimental stimuli participants completed a 4-point calibration to ensure the eye tracker was accurately tracking their eyes. During this trial, the participant will be asked to follow a red dot that will move to the four edges of a +.
Prosaccade task
Participants were asked to complete 16 gap trials as quickly and accurately as possible. At first the participants were instructed to look at a fixation point to centre their gaze. It was a white target displayed at the centre of the screen for 1000ms. Then they were told to focus on the appearing the red lateralised target, presented randomly to the left or right of the screen at 4° (visual angle) for 1200ms. The temporal gap in stimuli presentation is due to a 200ms blank interval screen which was displayed between the fading of the white fixation stimuli and the initial appearance of the red target.
Anti-saccade task
For anti-saccade task, the participants completed 24 gap trials with 4 practice trials. They were asked to look at the central white fixation presented for 1000ms before shifting their gaze and attentional focus to the opposite side of the screen from where the green target appeared. The green lateralised target was displayed randomly to the left or right side of the screen at 4° (visual angle) for 2000ms. There was a 200ms blank interval screen as a gap in between the fixation point and the target.
Procedure
The study was approved by the Lancaster University Psychology Department Ethics Committee. Prior to study commencement healthy younger adult volunteers were randomly to either the healthy control or healthy feigner (asked to feign ADHD) group. All individuals with a formal clinical diagnosis of ADHD were assigned to the ADHD group.
The participants were required to visit the lab in order to participate. Before commencing the study, the participants provided informed consent. After taking the required demographic data, participants were then screened for the probable presence of mild cognitive impairment using the ACE-III. They were also screened for any visual impairments using the RAF rule and Ishihara colour blindness test. Then, the participants were asked to complete the HADS, to screen for any psychological distress. Additionally, the ADHD participants were asked to complete the ASRS questionnaire, to determine the severity of the disorder.
On completion of the pre-study questionnaires, participants will be provided with Task information leaflet.
At this time control and ADHD participants were presented with a vignette (Appendix B) detailing an individual trying to feign ADHD. Comparatively, those assigned to the feigning condition were presented with a vignette (Appendix C) that explained the symptoms of ADHD and were asked to imagine themselves in a situation where they were to feign ADHD. All participants were then asked to complete the two eye movement tasks and the associated calibration trials. Fundamentally, at this time healthy controls and those with ADHD were asked to complete the tasks honestly to the best of their ability. In comparison, those in the feigning condition were asked to complete these tasks whilst pretending to have ADHD (without any over-exaggeration). On completion of the tasks, all participants were informed that they will be entered into a lottery to win a £25 and were provided with a debrief sheet (Appendix H), which explains the details of the study.
Data Analysis
DataViewer Software Version 3.2 was used to extract and analyse the raw EyeLink data. The data was then analysed online using a bespoke software SaccadeMachine. With the software spikes and noise were removed by filtering out frames with a velocity signal greater than 1,500 deg/s or with an acceleration signal greater than 100,000 deg 2 /sec. Fixations and saccadic events were identified using the EyeLink Parser, and the saccades were extracted alongside multiple temporal and spatial variables. Trials were eliminated when the participant did not direct their gaze on to the central fixation. The temporal window of 80-700ms used and measured from the onset of the target display. Anticipatory saccades made prior to 80ms, and excessively delayed saccades made after 700ms were removed. The data thus formed consists of the latency and error rate. Latency is the time taken of the correct trial whereas the error rate is the percentage of trials the participant got wrong. Data of one individual participant from the control group was removed as their ACE score was low suggesting the probable presence of mild cognitive impairment. Due to the lack of a formal diagnosis, data of an ADHD participant was removed.
All data was then assessed to ensure it met the assumptions required for statistical analysis. First, all data was assessed for the presence of any outliers (+/- 2SD). This analysis revealed there were 3 outliers for the both the pro- and anti-saccade measures. Given that these outliers may skew the subsequent analysis, all outliers were removed. The subsequent data was then checked to ensure it met the assumptions of normality. It was found that the prosaccade latency satisfied the normality condition (see Figure 1), hence one-way ANOVA was applied to investigate the difference in latency across the groups. As the data for prosaccade error rate was skewed (see Figure 2), Kruskal-Wallis H Test was used to determine the difference in data across the groups. Removing the outliers gave a data which satisfied normality condition for both anti-saccade latency (see Figure 3) and error rate (see Figure 4). Hence one-way ANOVA was used to test the difference for both the data across the groups and a post hoc Tukey’s Honest Significant Difference test was used to determine the significance of the difference in anti-saccade latency.
Participants
Previous studies explaining feigning in ADHD acquired data from around 90-100 samples (Booksh et.al., 2010; Frazier et.al., 2008; Harrison et.al., 2007). The study therefore aimed to recruit 90 participants, 30 each in ADHD, healthy controls, and healthy feigners faking the disorder. Participants with and without a clinical diagnosis of ADHD were selected using the opportunity sampling method. A total of 42 participants between the age of 18-35 volunteered and were recruited for the study through the university disability service (11%), posters (16%) and through word of mouth (73%). Data of two participants were removed as the eye tracker repeatedly lost the pupil during recording. All participants were rewarded with an equal chance to win one of 6 £25 vouchers. Thirty-one of the 42 participants were healthy younger adult controls. Of the healthy control participants 15 (7 females; Mage = 24.33; SDage=4.32) participated as healthy controls, and the remaining 16 (9 females; Mage = 24.25; SDage=1.88) as healthy feigners. Seven ADHD participants (6 females) with a mean age 22.71 (SD=2.22) completed the study. The severity of the ADHD symptoms was analysed using the Adult ADHD self-report scale (for more demographic details see Table 1). The exclusion criteria include participants: 1) with any visual (other than corrected-to-normal vision) impairment 2) with any cognitive impairment 3) with additional diagnosis of neurological conditions 4) without a proper clinical diagnosis of ADHD. The exclusion criteria were applied because these impairments may interfere with the participants performance in the task.
Prior to data analysis, one of the participants was removed from ADHD group due to the lack of proper clinical diagnosis. Furthermore, a control participant was excluded with the assumption of having a probable mild cognitive impairment because the individual scored less than 82 (cut-off) in the Addenbrooke’s Cognitive Examination-III (ACE-III) (see Table 1 for further demographic details).
Participants
Previous studies explaining feigning in ADHD acquired data from around 90-100 samples (Booksh et.al., 2010; Frazier et.al., 2008; Harrison et.al., 2007). The study therefore aimed to recruit 90 participants, 30 each in ADHD, healthy controls, and healthy feigners faking the disorder. Participants with and without a clinical diagnosis of ADHD were selected using the opportunity sampling method. A total of 42 participants between the age of 18-35 volunteered and were recruited for the study through the university disability service (11%), posters (16%) and through word of mouth (73%). Data of two participants were removed as the eye tracker repeatedly lost the pupil during recording. All participants were rewarded with an equal chance to win one of 6 £25 vouchers. Thirty-one of the 42 participants were healthy younger adult controls. Of the healthy control participants 15 (7 females; Mage = 24.33; SDage=4.32) participated as healthy controls, and the remaining 16 (9 females; Mage = 24.25; SDage=1.88) as healthy feigners. Seven ADHD participants (6 females) with a mean age 22.71 (SD=2.22) completed the study. The severity of the ADHD symptoms was analysed using the Adult ADHD self-report scale (for more demographic details see Table 1). The exclusion criteria include participants: 1) with any visual (other than corrected-to-normal vision) impairment 2) with any cognitive impairment 3) with additional diagnosis of neurological conditions 4) without a proper clinical diagnosis of ADHD. The exclusion criteria were applied because these impairments may interfere with the participants performance in the task.
Prior to data analysis, one of the participants was removed from ADHD group due to the lack of proper clinical diagnosis. Furthermore, a control participant was excluded with the assumption of having a probable mild cognitive impairment because the individual scored less than 82 (cut-off) in the Addenbrooke’s Cognitive Examination-III (ACE-III)
Stimuli and Apparatus
Addenbrooke’s Cognitive Examination-III (ACE-III)
The ACE-III, developed by Hodges et.al, is an extended cognitive screening technique. The items of the test produce 5 sub-scores totalling 100, with each sub-score corresponding to a different cognitive domain, such as attention (18 points), memory (26 points), verbal fluency (14 points), language (26 points), and visuospatial skills (16 points) (Noone, 2015). Higher scores indicate superior cognitive functioning within the given domain. The validated cut-off point for normal cognitive functioning is 82/100, therefore individuals who yield a total score of < 82 are assumed to have probable mild cognitive impairment. The ACE-III has proven reliability (α= 0.88), sensitivity (0.93), specificity (1.0) and concurrent validity with alternative cognitive assessments such as the ACE-R (r= 0.99, p < 0.01; Hsieh, 2013).
Ishihara Colour blindness test
Ishihara colour blindness developed by Dr Shinobu Ishihara, was used to assess the colour vision deficiency of congenital origin, particularly red-green deficiency (Ishihara, 2011). It consists of 24 coloured plates containing a circle of dots with random colours and numbers. Each plate includes primary and secondary colour dots, with the primary colours appearing in patterns or numbers, while secondary colours appear as the background (Shaygannejad et.al., 2012). Plates 1–15 were utilised because of the fact that the main goal was to separate the colour defects from the normal colour appreciation simply. The participants were instructed to read out the numbers aloud, without more than three seconds' delay. A participant with an error in reading the numbers of two or more plates were considered to be having an impaired colour vision.
Royal Air Force (RAF) ruler
The RAF near point rule is a 50cm long square rule with a cheek rest and slider holding a revolving four-sided cube. One of the 4 sides has a vertical line with a central dot for convergence fixation. It is used for determining the near point of convergence (NPC) (Sharma, 2017). The participant is instructed to keep a direct gaze on the dot while the slider descends and to report when the dot's image breaks into two. The cut-off point for NPC break and NPC recovery is between 5 and 7 cm respectively (Pang et.al., 2010)
Adult ADHD Self Report Scale (ASRS-v1.1; Kessler et al., 2005)
The severity of ADHD symptoms presented by individuals with ADHD was assessed using the ASRS. The ASRS is an 18-item checklist, developed by the World Health Organization (WHO) work group together with the WHO World Mental Health (WMH) Survey Initiative (Kessler et al., 2005), to screen ADHD in adult patients. Completion of the ASRS requires participants to indicate how much they agree that the given statement relates to their behaviour over the past 6 months. The questions are divided into 2 parts: part A and part B. Part A contains 6 questions that are indicative of symptoms consistent with ADHD and are used for screening purposes. A score of 4 or above denotes symptoms typical with ADHD. The final 12 questions in Part B provide a more detailed breakdown of the specific symptoms an individual is presenting. The scale has high concurrent validity, and the internal consistency of the scale Cronbach’s α was found to be 0.88 (Adler et.al., 2006).
Hospital Anxiety and Depression Scale (HADS)
Hospital Anxiety and Depression Scale was developed by Zigmond and Snaith in 1983. It is a 14-item measure, used to detect the psychological distress of the participants (Zigmond & Snaith, 1983). Seven of the items measure anxiety (HADS-A), while the remaining seven measures the depressive symptoms (HADS-D). For each item, the participant is asked to indicate on a four-point scale the degree to which they feel a given statement relates to how they were feeling for the past week. The overall score for both anxiety and depression is 21. A score of 0-7 represents “normal”, 8-10 indicates “mild”, 11-14 “moderate and 15-21 indicates “severe” (Pais-Ribeiro et al., 2018). The scale is reliable and valid in measuring symptoms in both general and psychiatric patients (Bjelland et.al., 2002).
Eye-Tracking Measurement
Participants eye movements were recorded via the EyeLink Desktop 1000 at 500Hz. To minimize the head movements, a chin rest was used. Participants were seated approximately 55cm from the computer monitor (monitor run at 60 Hz). All the stimuli used for the study were created and controlled using Experiment Builder Software Version 1.10.1630. Two different computers are used for the eye-tracking system: a host PC which tracks the eye movements and determines their actual gaze positions and a display computer which shows the stimuli during the calibration and experimental trial.
Calibration
Prior to presenting the experimental stimuli participants completed a 4-point calibration to ensure the eye tracker was accurately tracking their eyes. During this trial, the participant will be asked to follow a red dot that will move to the four edges of a +.
Prosaccade task
Participants were asked to complete 16 gap trials as quickly and accurately as possible. At first the participants were instructed to look at a fixation point to centre their gaze. It was a white target displayed at the centre of the screen for 1000ms. Then they were told to focus on the appearing the red lateralised target, presented randomly to the left or right of the screen at 4° (visual angle) for 1200ms. The temporal gap in stimuli presentation is due to a 200ms blank interval screen which was displayed between the fading of the white fixation stimuli and the initial appearance of the red target.
Anti-saccade task
For anti-saccade task, the participants completed 24 gap trials with 4 practice trials. They were asked to look at the central white fixation presented for 1000ms before shifting their gaze and attentional focus to the opposite side of the screen from where the green target appeared. The green lateralised target was displayed randomly to the left or right side of the screen at 4° (visual angle) for 2000ms. There was a 200ms blank interval screen as a gap in between the fixation point and the target.
Procedure
The study was approved by the Lancaster University Psychology Department Ethics Committee. Prior to study commencement healthy younger adult volunteers were randomly to either the healthy control or healthy feigner (asked to feign ADHD) group. All individuals with a formal clinical diagnosis of ADHD were assigned to the ADHD group.
The participants were required to visit the lab in order to participate. Before commencing the study, the participants provided informed consent. After taking the required demographic data, participants were then screened for the probable presence of mild cognitive impairment using the ACE-III. They were also screened for any visual impairments using the RAF rule and Ishihara colour blindness test. Then, the participants were asked to complete the HADS, to screen for any psychological distress. Additionally, the ADHD participants were asked to complete the ASRS questionnaire, to determine the severity of the disorder.
On completion of the pre-study questionnaires, participants will be provided with Task information leaflet.
At this time control and ADHD participants were presented with a vignette (Appendix B) detailing an individual trying to feign ADHD. Comparatively, those assigned to the feigning condition were presented with a vignette (Appendix C) that explained the symptoms of ADHD and were asked to imagine themselves in a situation where they were to feign ADHD. All participants were then asked to complete the two eye movement tasks and the associated calibration trials. Fundamentally, at this time healthy controls and those with ADHD were asked to complete the tasks honestly to the best of their ability. In comparison, those in the feigning condition were asked to complete these tasks whilst pretending to have ADHD (without any over-exaggeration). On completion of the tasks, all participants were informed that they will be entered into a lottery to win a £25 and were provided with a debrief sheet (Appendix H), which explains the details of the study.
Data Analysis
DataViewer Software Version 3.2 was used to extract and analyse the raw EyeLink data. The data was then analysed online using a bespoke software SaccadeMachine. With the software spikes and noise were removed by filtering out frames with a velocity signal greater than 1,500 deg/s or with an acceleration signal greater than 100,000 deg 2 /sec. Fixations and saccadic events were identified using the EyeLink Parser, and the saccades were extracted alongside multiple temporal and spatial variables. Trials were eliminated when the participant did not direct their gaze on to the central fixation. The temporal window of 80-700ms used and measured from the onset of the target display. Anticipatory saccades made prior to 80ms, and excessively delayed saccades made after 700ms were removed. The data thus formed consists of the latency and error rate. Latency is the time taken of the correct trial whereas the error rate is the percentage of trials the participant got wrong. Data of one individual participant from the control group was removed as their ACE score was low suggesting the probable presence of mild cognitive impairment. Due to the lack of a formal diagnosis, data of an ADHD participant was removed.
All data was then assessed to ensure it met the assumptions required for statistical analysis. First, all data was assessed for the presence of any outliers (+/- 2SD). This analysis revealed there were 3 outliers for the both the pro- and anti-saccade measures. Given that these outliers may skew the subsequent analysis, all outliers were removed. The subsequent data was then checked to ensure it met the assumptions of normality. It was found that the prosaccade latency satisfied the normality condition (see Figure 1), hence one-way ANOVA was applied to investigate the difference in latency across the groups. As the data for prosaccade error rate was skewed (see Figure 2), Kruskal-Wallis H Test was used to determine the difference in data across the groups. Removing the outliers gave a data which satisfied normality condition for both anti-saccade latency (see Figure 3) and error rate (see Figure 4). Hence one-way ANOVA was used to test the difference for both the data across the groups and a post hoc Tukey’s Honest Significant Difference test was used to determine the significance of the difference in anti-saccade latency.
Publisher
Lancaster University
Format
SPSS.sav for results
Word.doc for demographic and data acquistion form
PDF for consent form
Word.doc for demographic and data acquistion form
PDF for consent form
Identifier
George_2022
Contributor
Lettie and Delyth
Rights
Open
Relation
None
Language
English
Type
Data and Text
Coverage
LA1 4YF
LUSTRE
Supervisor
Dr Megan Rose Readman
Project Level
MSc
Topic
Clinical
Cognitive, Perception
Cognitive, Perception
Sample Size
38
Statistical Analysis Type
ANOVA
Files
Collection
Citation
Reva Maria George , “Eye tracking and Attention Deficit Hyperactivity Disorder (ADHD): Can eye tracking identify the feigning of ADHD?,” LUSTRE, accessed May 1, 2024, https://www.johnntowse.com/LUSTRE/items/show/151.