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A computerized tablet with visual feedback of hand position for functional magnetic resonance imaging.

Karimpoor M, Tam F, Strother SC, Fischer CE, Schweizer TA, Graham SJ - Front Hum Neurosci (2015)

Bottom Line: A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display.The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP.Quantitative analysis of the behavioral results indicated improved writing performance with VFHP.

View Article: PubMed Central - PubMed

Affiliation: Graham Laboratory, Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre Toronto, ON, Canada ; Department of Medical Biophysics, University of Toronto Faculty of Medicine Toronto, ON, Canada.

ABSTRACT
Neuropsychological tests behavioral tasks that very commonly involve handwriting and drawing are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI) may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP), a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important.

No MeSH data available.


Example visual stimuli for Experiment Two. Tablet output is shown for participant one.
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Figure 4: Example visual stimuli for Experiment Two. Tablet output is shown for participant one.

Mentions: Using the same set-up, an additional cohort of 9 individuals (age: 20–35, 4 male, 5 female) performed Experiment Two, which was designed to investigate learning effects for the two tablet conditions using a slightly modified version of the paragraph copying test (Figure 4). The rationale for performing this experiment was that if performance differences were observed in the prior behavioral experiments (judged as likely) then these differences could arise from participants having insufficient time to learn how to interact with the tablet in one of the two conditions. To investigate whether this was the case, it was necessary to study tablet performance over a longer time duration. Each trial of the learning task consisted of copying three paragraphs of differing content. There were four trials conducted for each of the tablet conditions. In successive trials, words within the paragraph for each trial were kept identical, but re-ordered with preservation of grammar and syntax. This procedure helped the participants to maintain attention to the task and to minimize copying by memory. Participants were instructed to lift the stylus off the tablet once they had finished copying each paragraph, such that force data could be used to index task completion. Prior to starting the experiment, each participant was provided with a brief instruction session so that they were familiarized with (but not extensively trained on) the task requirements for operating the tablet system in the “with VFHP” and “without VFHP” conditions. This was achieved by having the participant draw a circle, draw three parallel lines, and write the letter “A” in each condition. Participants then started the experiment using one tablet condition (either “with VFHP” or “without VFHP”), performed one trial of the four modified paragraph tasks, then switched to the other tablet condition for the next trial, and continued to alter between conditions until all trials were completed. The start condition was randomized across participants. After completing the writing tasks, subjects were asked to complete a questionnaire that involved rating different aspects of ease-of-use during performance in both tablet conditions. Task performance in both conditions was subsequently assessed primarily in terms of the time that the stylus remained in contact with the tablet, as this parameter provided the most distinction between the two tablet conditions in Experiment One (see Results, Figure 5). Specifically, the stylus contact time across trials for the two tablet conditions was assessed using a three-way mixed-effects Analysis of Variance (ANOVA), with tablet condition (with VFHP, without VFHP) and trial number (1–4) as fixed effects, and participants as the random effects.


A computerized tablet with visual feedback of hand position for functional magnetic resonance imaging.

Karimpoor M, Tam F, Strother SC, Fischer CE, Schweizer TA, Graham SJ - Front Hum Neurosci (2015)

Example visual stimuli for Experiment Two. Tablet output is shown for participant one.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4373274&req=5

Figure 4: Example visual stimuli for Experiment Two. Tablet output is shown for participant one.
Mentions: Using the same set-up, an additional cohort of 9 individuals (age: 20–35, 4 male, 5 female) performed Experiment Two, which was designed to investigate learning effects for the two tablet conditions using a slightly modified version of the paragraph copying test (Figure 4). The rationale for performing this experiment was that if performance differences were observed in the prior behavioral experiments (judged as likely) then these differences could arise from participants having insufficient time to learn how to interact with the tablet in one of the two conditions. To investigate whether this was the case, it was necessary to study tablet performance over a longer time duration. Each trial of the learning task consisted of copying three paragraphs of differing content. There were four trials conducted for each of the tablet conditions. In successive trials, words within the paragraph for each trial were kept identical, but re-ordered with preservation of grammar and syntax. This procedure helped the participants to maintain attention to the task and to minimize copying by memory. Participants were instructed to lift the stylus off the tablet once they had finished copying each paragraph, such that force data could be used to index task completion. Prior to starting the experiment, each participant was provided with a brief instruction session so that they were familiarized with (but not extensively trained on) the task requirements for operating the tablet system in the “with VFHP” and “without VFHP” conditions. This was achieved by having the participant draw a circle, draw three parallel lines, and write the letter “A” in each condition. Participants then started the experiment using one tablet condition (either “with VFHP” or “without VFHP”), performed one trial of the four modified paragraph tasks, then switched to the other tablet condition for the next trial, and continued to alter between conditions until all trials were completed. The start condition was randomized across participants. After completing the writing tasks, subjects were asked to complete a questionnaire that involved rating different aspects of ease-of-use during performance in both tablet conditions. Task performance in both conditions was subsequently assessed primarily in terms of the time that the stylus remained in contact with the tablet, as this parameter provided the most distinction between the two tablet conditions in Experiment One (see Results, Figure 5). Specifically, the stylus contact time across trials for the two tablet conditions was assessed using a three-way mixed-effects Analysis of Variance (ANOVA), with tablet condition (with VFHP, without VFHP) and trial number (1–4) as fixed effects, and participants as the random effects.

Bottom Line: A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display.The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP.Quantitative analysis of the behavioral results indicated improved writing performance with VFHP.

View Article: PubMed Central - PubMed

Affiliation: Graham Laboratory, Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre Toronto, ON, Canada ; Department of Medical Biophysics, University of Toronto Faculty of Medicine Toronto, ON, Canada.

ABSTRACT
Neuropsychological tests behavioral tasks that very commonly involve handwriting and drawing are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI) may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP), a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important.

No MeSH data available.