Limits...
Conditional associative learning examined in a paralyzed patient with amyotrophic lateral sclerosis using brain-computer interface technology.

Iversen I, Ghanayim N, Kübler A, Neumann N, Birbaumer N, Kaiser J - Behav Brain Funct (2008)

Bottom Line: A smiley was presented as a reward when he hit the correct target.In contrast, the patient showed clear evidence that A-B and B-C training had resulted in formation of equivalence classes.The brain-computer interface technology combined with the matching to sample method is a useful way to assess various cognitive abilities of severely paralyzed patients, who are without reliable motor control.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Medical Psychology, Goethe-University, Frankfurt am Main, Germany. j.kaiser@med.uni-frankfurt.de.

ABSTRACT

Background: Brain-computer interface methodology based on self-regulation of slow-cortical potentials (SCPs) of the EEG (electroencephalogram) was used to assess conditional associative learning in one severely paralyzed, late-stage ALS patient. After having been taught arbitrary stimulus relations, he was evaluated for formation of equivalence classes among the trained stimuli.

Methods: A monitor presented visual information in two targets. The method of teaching was matching to sample. Three types of stimuli were presented: signs (A), colored disks (B), and geometrical shapes (C). The sample was one type, and the choice was between two stimuli from another type. The patient used his SCP to steer a cursor to one of the targets. A smiley was presented as a reward when he hit the correct target. The patient was taught A-B and B-C (sample - comparison) matching with three stimuli of each type. Tests for stimulus equivalence involved the untaught B-A, C-B, A-C, and C-A relations. An additional test was discrimination between all three stimuli of one equivalence class presented together versus three unrelated stimuli. The patient also had sessions with identity matching using the same stimuli.

Results: The patient showed high accuracy, close to 100%, on identity matching and could therefore discriminate the stimuli and control the cursor correctly. Acquisition of A-B matching took 11 sessions (of 70 trials each) and had to be broken into simpler units before he could learn it. Acquisition of B-C matching took two sessions. The patient passed all equivalence class tests at 90% or higher.

Conclusion: The patient may have had a deficit in acquisition of the first conditional association of signs and colored disks. In contrast, the patient showed clear evidence that A-B and B-C training had resulted in formation of equivalence classes. The brain-computer interface technology combined with the matching to sample method is a useful way to assess various cognitive abilities of severely paralyzed patients, who are without reliable motor control.

No MeSH data available.


Percent correct for each of the A → B relations (1 through 3) and all three relations together. Numbers above the graph indicate which relations were presented in mixed order within a session. Along the X-axis, 0's indicate a score of zero, and x's indicate that a given relation was not presented in a session.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2599893&req=5

Figure 4: Percent correct for each of the A → B relations (1 through 3) and all three relations together. Numbers above the graph indicate which relations were presented in mixed order within a session. Along the X-axis, 0's indicate a score of zero, and x's indicate that a given relation was not presented in a session.

Mentions: The percent correct for each of the 11 sessions of teaching the A → B relations is presented in Fig. 4. Data are shown for each of the three relations (A1 → B1, A2 → B2, and A3 → B3) and for all relations together. During the first five sessions with all relations presented in mixed order within sessions, the patient did not learn the relations and even was at 0% correct for the A2 → B2 trials in sessions 3 and 5. Therefore, the procedure was simplified to present only two of the relations within each session until the patient learned the relations. The percent correct immediately increased. When all three relations were again presented in mixed order in session 11, the patient scored at or above 90% correct on all three relations and had therefore learned the arbitrary conditional association between the type A stimuli (signs) and the type B stimuli (colored disks).


Conditional associative learning examined in a paralyzed patient with amyotrophic lateral sclerosis using brain-computer interface technology.

Iversen I, Ghanayim N, Kübler A, Neumann N, Birbaumer N, Kaiser J - Behav Brain Funct (2008)

Percent correct for each of the A → B relations (1 through 3) and all three relations together. Numbers above the graph indicate which relations were presented in mixed order within a session. Along the X-axis, 0's indicate a score of zero, and x's indicate that a given relation was not presented in a session.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2599893&req=5

Figure 4: Percent correct for each of the A → B relations (1 through 3) and all three relations together. Numbers above the graph indicate which relations were presented in mixed order within a session. Along the X-axis, 0's indicate a score of zero, and x's indicate that a given relation was not presented in a session.
Mentions: The percent correct for each of the 11 sessions of teaching the A → B relations is presented in Fig. 4. Data are shown for each of the three relations (A1 → B1, A2 → B2, and A3 → B3) and for all relations together. During the first five sessions with all relations presented in mixed order within sessions, the patient did not learn the relations and even was at 0% correct for the A2 → B2 trials in sessions 3 and 5. Therefore, the procedure was simplified to present only two of the relations within each session until the patient learned the relations. The percent correct immediately increased. When all three relations were again presented in mixed order in session 11, the patient scored at or above 90% correct on all three relations and had therefore learned the arbitrary conditional association between the type A stimuli (signs) and the type B stimuli (colored disks).

Bottom Line: A smiley was presented as a reward when he hit the correct target.In contrast, the patient showed clear evidence that A-B and B-C training had resulted in formation of equivalence classes.The brain-computer interface technology combined with the matching to sample method is a useful way to assess various cognitive abilities of severely paralyzed patients, who are without reliable motor control.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Medical Psychology, Goethe-University, Frankfurt am Main, Germany. j.kaiser@med.uni-frankfurt.de.

ABSTRACT

Background: Brain-computer interface methodology based on self-regulation of slow-cortical potentials (SCPs) of the EEG (electroencephalogram) was used to assess conditional associative learning in one severely paralyzed, late-stage ALS patient. After having been taught arbitrary stimulus relations, he was evaluated for formation of equivalence classes among the trained stimuli.

Methods: A monitor presented visual information in two targets. The method of teaching was matching to sample. Three types of stimuli were presented: signs (A), colored disks (B), and geometrical shapes (C). The sample was one type, and the choice was between two stimuli from another type. The patient used his SCP to steer a cursor to one of the targets. A smiley was presented as a reward when he hit the correct target. The patient was taught A-B and B-C (sample - comparison) matching with three stimuli of each type. Tests for stimulus equivalence involved the untaught B-A, C-B, A-C, and C-A relations. An additional test was discrimination between all three stimuli of one equivalence class presented together versus three unrelated stimuli. The patient also had sessions with identity matching using the same stimuli.

Results: The patient showed high accuracy, close to 100%, on identity matching and could therefore discriminate the stimuli and control the cursor correctly. Acquisition of A-B matching took 11 sessions (of 70 trials each) and had to be broken into simpler units before he could learn it. Acquisition of B-C matching took two sessions. The patient passed all equivalence class tests at 90% or higher.

Conclusion: The patient may have had a deficit in acquisition of the first conditional association of signs and colored disks. In contrast, the patient showed clear evidence that A-B and B-C training had resulted in formation of equivalence classes. The brain-computer interface technology combined with the matching to sample method is a useful way to assess various cognitive abilities of severely paralyzed patients, who are without reliable motor control.

No MeSH data available.