114
Effects of Single Doses of Alpidem, Lorazepam, and Placebo on Memory and Attention in Healthy Young and Elderly Volunteers W. Satzger, R. R. Engel, E. Ferguson, H. Kapfhammer, F. X. Eich *, H. Hippius Psychiatrie Hospital, UniversityofMunich, Munieh, FRG; *L.E.R.S. - Clinical Research, Munieh, FRG
The aim of the present study was to compare the effects of alpidem, a new imidazopyridine derivate with benzodiazepine-like anxiolytic effects, with those of lorazepam and placebo on memory and attention in two age groups of healthy volunteers. The study design was that of a randomized doublli:-blind crossover trial with 12 young (1830 years old) and 12 elderly (65-80) subjects. At weekly intervals, each subject was administered single oral doses of 25 mg alpidem, 50 mg alpidem, I mg lorazepam, and placebo in a randomized sequence. Computerized memory and attention tests were performed 90 minutes before and 320 minutes after drug administration. Lorazepam and alpidem 50 mg produced memory impairments: for verbal memory tests the difference against placebo was highly significant for both drugs, while for visual memory this impairment was significant for lorazepam only. No memory effects were seen with 25 mg alpidem. There were no significant drug effects on attention, suggesting a specific amnestic effect not explained by general sedation. Performance of the elderly subjects was much lower than that of the younger ones in both memory and attention tasks. It was not possible to observe any interaction effects between drug and age.
Introduction Alpidem is a new imidazopyridine derivative that binds to central omega\ receptor sites. In experimental animal models, alpidem showed antianxiety and anticonvulsant properties similar to those of benzodiazepines; however, in doses up to 100 mg it showed fewer myorelaxant properties and practically no drug dependence (Museh, 1985). In controlled human studies with volunteers (Saletu et al., 1986; Curran et al., 1987; Hindmarch et al., 1988), alpidem affected memory Pharmacopsychiatry23 (1990) 114-119 (Supplement) © GeorgThieme Verlag Stuttgart· New York
Die akute Wirkung von Alpidem, Lorazepam und Plazebo auf Gedächtnis und Aufmerksamkeit junger und alter gesunder Probanden Ziel der Studie war der Vergleich der aufmerksamkeits- und gedächtnisbeeinträchtigenden Wirkung von Alpidem, einem neuen Imidazopyridinderivat mit benzodiazepin-ähnlicher anxiolytischer Wirkung, im Vergleich zu Lorazepam und Plazebo in zwei Altersgruppen gesunder Probanden. In einem randomisierten doppelt-blinden crossover Design wurden 12junge(l8-30Jahre)und 12 alte (6580 Jahre) Versuchspersonen untersucht. Im Abstand von einer Woche wurden oral 25 mg Alpidem, 50 mg Alpidem, 1 mg Lorazepam und Plazebo randomisiert verabreicht. Rechnergestützte Gedächtnis- und Aufmerksamkeitstests wurden 90 Minuten vor und 320 Minuten nach Einnahme der Substanzen durchgeführt. Visuelle Aufmerksamkeitsund Gedächtnisitems unterschieden sich nur in der zeitgleichen oder verzögerten Darbietung von vier Auswahlstimuli im Vergleich zu einem Targetstimulus. Lorazepam und 50 mg Alpidem beeinträchtigten die Gedächtnisleistung: In verbalen Gedächtnistests wurde der Unterschied zu Plazebo für beide Substanzen signifikant, während er in visuellen Gedächtnistests nur für Lorazepam signifikant wurde. Keine Gedächtsniseinbuße fand sich unter 25 mg Alpidem. In Aufmerksamkeitstests hingegen traten keine substanzbezogenen Einbußen auf. Dieses Ergebnis spricht für eine spezifisch amnestische Wirkung der Substanzen, die nicht durch eine generelle Sedation erklärt werden kann. Ältere Versuchspersonen zeigten eine deutlich niedrigere Leistung sowohl in Gedächtnis- wie in Aufmerksamkeitsaufgaben als junge Versuchspersonen, es fand sich jedoch keine Wechselwirkung zwischen den Faktoren Substanz und Alter.
to a lesser degree than anxiolytically comparable doses of lorazepam. Since there is some debate as to whether the sideeffects of benzodiazepines are greater in elderly healthy subjects than in younger ones (pomara et al., 1984; Hinrichs & Ghoneim, 1987; Hindmarch et al., 1988), two age groups were included in the present study. A computerized running word recognition test previously shown to be highly sensitive to benzodiazepine effects on memory (Clark et al., 1979; Sold et al., 1983) was the main variable. Lorazepam was chosen as the comparison agent because of its well-known amnestic action (Scharf et al., 1983; Lister & File, 1984) and a similar pharmacokinetic profile in young and elderly subjects (e.g., Meyer, 1982).
Downloaded by: National University of Singapore. Copyrighted material.
Summary
Pharmacopsychiatry 23 (1990)
Alpidem vs. Lorazepam Experimental
Time (minutes)
1
schedule Procedure
Methods
Subjects The 24 subjects were healthy, paid volunteers. Twelve subjects, seven women and five men, were tested in each ofthe two age groups: young (18 - 30 years old) and elderly (65 -80). Subjects gave written informed consent to participation.
-90
Standard breakfast
-60 -60 -52 -50 -42
Block 1 1 Running word recoqnition Tone discrimination Immediate visual memory Break
-30 -30 -22 -18 -14 -10 -2
Block 2 Running word recognition Long-term visual memory Visual attention Divided attention Immediate visual memory Mood evaluation
The study was double-blind, randomized, and crossover in design. Each subject received 25 mg alpidem, 50 mg alpidem, I mg lorazepam, or placebo at weekly intervals in identical capsules according to a latin square.
On the screening day, subjects received a medical and psychological examination and a 45-minute training session on the computerized tasks with items different from those used on the test days. On the four test days, substance intake was at 9.30 am. Two baseline blocks of computerized psychometrie testing were done before and seven blocks after medication (Table I). Item presentation and data collection were controlled by an IBM-compatible AT Pe.
±O
Drug Intake
+10 +10 +18 +22 +26 +30 +38 +40
Block 3 Running word recognition Long-term visual memory Visual attention Divided attention Immediate visual memory Mood evaluation Break
+50
Block 4 (same as block 3)
+90
Block 5 (same as block 3)
Treatment
Procedure
Tasks
+200
Standard lunch
+235
Block 8 (same as block 3)
Running word recognition. Five hundred nouns with a frequency of usage greater than I: 110,000 were selected from Meier (1964) and randomly allocated to a preliminary list and eight test lists. The 50 new words of each list were mixed with 50 old words from the preceeding list. Thus in each block, 100 words were presented visually (15 mm letters) and auditorily over headphones for a maximum of six seconds. The subjects' task was to classify each word as "old" (i.e., seen in the previous test block) or "new" (i.e., presented for the first time).
+275 +315
Block 9 (same as block 3) Side-effect evaluation Test behavior evaluation by research assistant
Tone discrimination. High (700 Hz) and low (300 Hz) tones with a duration of 250 ms and a ISI of 800 ms to 3000 ms were presented at an average ratio of 1:2. Subjects were instructed to press a button as soon as a high tone was heard.
+130 +130
Block 6 (same as block 3) Mood evaluation by research assistant
+170
Block 7 (same as block 3)
Learn trial
While Lister (1985), Curran (1986), Curran et al. (1987), Greenblatt et al. (1988), Lister et al. (1988), and Preston et al. (1988) have suggested that benzodiazepine-induced anterograde amnesia is primarily the consequence of benzodiazepines' global sedative action, Clarke et al. (1970), Sold et al. (1983), and Rodrigo & Lusiardo (1988) have proposed a specific benzodiazepine-induced encoding deficit. In order to further evaluate the specificity of benzodiazepine-induced memory impairment, four visual matching-to-sample tasks were constructed, dilTering solely in the length of the delay between presentation of a target stimulus and the appearance of four choice stimuli. The simultaneous presentation of the target stimulus and the choice stimuli was to measure attention only, while the delayed presentation required episodic memory as weil. The aims of the present study were therefore (I) to assess the degree of anterograde amnesia in young and elderly volunteers caused by alpidem as against lorazepam and placebo and (2) to determine the intluence of alpidem and lorazepam on similarly constructed visual attention and memory tasks.
Visual attention. Twenty-five parallel matching-tosampie tasks (8 x visual attention, 8 x divided visual attention, 9 x immediate visual memory), each consisting of 18 items, were constructed. Each item consisted of a target stimulus and a set of four simultaneously presented, numbered choice stimuli (one target stimulus and three distractors). Target stimuli consisted of motivating abstract and realistic colored pictures and the distractors differed from target stimuli to some degree in color, size, or content. Each item was presented on the screen for up to 20 seconds or until subjects pressed the correct button, whichever came first. Ifthe response was an error, the item remained on the screen and subjects could choose again. The 18 visual attention items consisted of a target stimulus in the left half of the screen and four choice stimuli on the right. Divided visual attention. Eighteen visual attention items were presented as the primary task. In addition, subjects simultaneously performed the tone discrimination task. Immediate visual memory (l5-second delayed recognition). Eighteen items were presented in the following manner: a target stimulus was shown for four seconds followed by 15 seconds of tone discrimination as distraction. Then the four choice stimuli were presented simultaneously and subjects were to press the corresponding button as soon as possible. Long-term visual memory (20-minute delayed recognition). The same 18 sets of choice stimuli from the immediate visual memory subtest were shown again in the following test block (approximately 20 minutes after their first presentation), and subjects were expected to recognize the target stimuli. The position of the target
Downloaded by: National University of Singapore. Copyrighted material.
Teble 1
115
W Satzger. R. R. Engel, E. Ferguson et al.
Pharmacopsychiatry 23 (1990)
Table 2 Means (sd) or frequencies of screening variables for young and older subjects with t-test comparisons (ss no. of correct responses, s = seconds) Biographical variables Females Males Weight (kg) Age (years) Years of education
Young subjects (n = 12)
Older subjects (n = 12)
7 5 69.7 24.1 14.5
(9.09) (3.27) (2.35)
7 5 75.2 68.3 11.8
114.26 112.50 114.75 11.8 12.5 11.7 10.4 13.0 14.2 12.0 11.0 12.7 11.2 12.8
(6.9) (7.0) (8.7) (1.40) (2.02) (3.04) (1.92) (1.16) (1.65) (2.98) (2.15) (1.65) (1.96) (0.93)
114.67 116.33 110.92 11.5 12.4 10.6 9.9 12.5 9.7 7.8 9.4 9.5 9.3 12.3
23.1 57.5 116.1 8.3 7.3 15.4 15.0
(8.88) (15.11) (13.33) (1.37) (2.57) (0.79) (1.04)
38.4 89.1 107.3 5.2 4.5 12.3 9.7
= scaled score, nc =
P
(11.42) (4.45) (2.65)
1.54 27.67 2.60
.137
.000 .016
WAlS Total 10 Verbal 10 Performance 10 Information (ss) Comprehension (ss) Digit Span (ss) Arithmetic (ss) Similarities (ss) Digit Symbol (ss) Picture Arrangement (ss) Picture Completion (ss) Block Design (ss) Object Assembly (ss) Vocabulary (ss)
(6.7) (9.2) (7.7) (2.23) (1.97) (2.70) (2.53) (1.67) (2.26) (1.40) (3.28) (1.88) (2.46) (1.61)
0.15 1.15 1.14 0.44 0.10 0.92 0.54 0.99 5.56 4.38 1.47 4.49 2.11 0.93
.883 .263
3.65 5.05 1.86 5.17 3.23 4.59 5.29
.001
.266 .666 .920 .367 .592 .333
.000 .000 .156
.000 .046
.364
Visual-motor and memory tests Trail making A (s) Trail making B (s) Letter cancellation test d2 (nc) Benton (nc) AVLT1 sI trial 1 (nc) AVLT5 1h trial (nc) AVLT6 1h trial (nc) 1Auditory
(11.47) (15.60) (9.61) (1.54) (1.44) (2.18) (3.27)
.000 .076
.000 .004 .000 .000
Verbal Learning Test (for all test citations see Lezak, 1983)
stimulus among the distractors was, however, changed in order to prevent simple position learning. Mood evaluation. Subjects rated their mood at the end of each test block and the research assistant rated subjects' mood 130 minutes post drug. Each of the 15 dimensions of the EWL-G (Rösler et a1., 1980) were transformed into seven-point rating scales and these items were presented with three further items (wakefulness, physical well-being, effectiveness). Additionally, the research assistant rated subjects' personality with the Nürnberger Alters Rating Scale (Oswald & Fleischman, 1986) and subjects' test behavior according to 11 criteria (understanding of test instructions, willingness to continue, interest in own performance, cooperation, carefulness, motivation, self-
Effects of Single Doses of Alpidem, Lorazepam, and Placebo on Memory and Attention in Healthy Young and Elderly Volunteers W. Satzger, R. R. Engel, E. Ferguson, H. Kapfhammer, F. X. Eich *, H. Hippius Psychiatrie Hospital, UniversityofMunich, Munieh, FRG; *L.E.R.S. - Clinical Research, Munieh, FRG
The aim of the present study was to compare the effects of alpidem, a new imidazopyridine derivate with benzodiazepine-like anxiolytic effects, with those of lorazepam and placebo on memory and attention in two age groups of healthy volunteers. The study design was that of a randomized doublli:-blind crossover trial with 12 young (1830 years old) and 12 elderly (65-80) subjects. At weekly intervals, each subject was administered single oral doses of 25 mg alpidem, 50 mg alpidem, I mg lorazepam, and placebo in a randomized sequence. Computerized memory and attention tests were performed 90 minutes before and 320 minutes after drug administration. Lorazepam and alpidem 50 mg produced memory impairments: for verbal memory tests the difference against placebo was highly significant for both drugs, while for visual memory this impairment was significant for lorazepam only. No memory effects were seen with 25 mg alpidem. There were no significant drug effects on attention, suggesting a specific amnestic effect not explained by general sedation. Performance of the elderly subjects was much lower than that of the younger ones in both memory and attention tasks. It was not possible to observe any interaction effects between drug and age.
Introduction Alpidem is a new imidazopyridine derivative that binds to central omega\ receptor sites. In experimental animal models, alpidem showed antianxiety and anticonvulsant properties similar to those of benzodiazepines; however, in doses up to 100 mg it showed fewer myorelaxant properties and practically no drug dependence (Museh, 1985). In controlled human studies with volunteers (Saletu et al., 1986; Curran et al., 1987; Hindmarch et al., 1988), alpidem affected memory Pharmacopsychiatry23 (1990) 114-119 (Supplement) © GeorgThieme Verlag Stuttgart· New York
Die akute Wirkung von Alpidem, Lorazepam und Plazebo auf Gedächtnis und Aufmerksamkeit junger und alter gesunder Probanden Ziel der Studie war der Vergleich der aufmerksamkeits- und gedächtnisbeeinträchtigenden Wirkung von Alpidem, einem neuen Imidazopyridinderivat mit benzodiazepin-ähnlicher anxiolytischer Wirkung, im Vergleich zu Lorazepam und Plazebo in zwei Altersgruppen gesunder Probanden. In einem randomisierten doppelt-blinden crossover Design wurden 12junge(l8-30Jahre)und 12 alte (6580 Jahre) Versuchspersonen untersucht. Im Abstand von einer Woche wurden oral 25 mg Alpidem, 50 mg Alpidem, 1 mg Lorazepam und Plazebo randomisiert verabreicht. Rechnergestützte Gedächtnis- und Aufmerksamkeitstests wurden 90 Minuten vor und 320 Minuten nach Einnahme der Substanzen durchgeführt. Visuelle Aufmerksamkeitsund Gedächtnisitems unterschieden sich nur in der zeitgleichen oder verzögerten Darbietung von vier Auswahlstimuli im Vergleich zu einem Targetstimulus. Lorazepam und 50 mg Alpidem beeinträchtigten die Gedächtnisleistung: In verbalen Gedächtnistests wurde der Unterschied zu Plazebo für beide Substanzen signifikant, während er in visuellen Gedächtnistests nur für Lorazepam signifikant wurde. Keine Gedächtsniseinbuße fand sich unter 25 mg Alpidem. In Aufmerksamkeitstests hingegen traten keine substanzbezogenen Einbußen auf. Dieses Ergebnis spricht für eine spezifisch amnestische Wirkung der Substanzen, die nicht durch eine generelle Sedation erklärt werden kann. Ältere Versuchspersonen zeigten eine deutlich niedrigere Leistung sowohl in Gedächtnis- wie in Aufmerksamkeitsaufgaben als junge Versuchspersonen, es fand sich jedoch keine Wechselwirkung zwischen den Faktoren Substanz und Alter.
to a lesser degree than anxiolytically comparable doses of lorazepam. Since there is some debate as to whether the sideeffects of benzodiazepines are greater in elderly healthy subjects than in younger ones (pomara et al., 1984; Hinrichs & Ghoneim, 1987; Hindmarch et al., 1988), two age groups were included in the present study. A computerized running word recognition test previously shown to be highly sensitive to benzodiazepine effects on memory (Clark et al., 1979; Sold et al., 1983) was the main variable. Lorazepam was chosen as the comparison agent because of its well-known amnestic action (Scharf et al., 1983; Lister & File, 1984) and a similar pharmacokinetic profile in young and elderly subjects (e.g., Meyer, 1982).
Downloaded by: National University of Singapore. Copyrighted material.
Summary
Pharmacopsychiatry 23 (1990)
Alpidem vs. Lorazepam Experimental
Time (minutes)
1
schedule Procedure
Methods
Subjects The 24 subjects were healthy, paid volunteers. Twelve subjects, seven women and five men, were tested in each ofthe two age groups: young (18 - 30 years old) and elderly (65 -80). Subjects gave written informed consent to participation.
-90
Standard breakfast
-60 -60 -52 -50 -42
Block 1 1 Running word recoqnition Tone discrimination Immediate visual memory Break
-30 -30 -22 -18 -14 -10 -2
Block 2 Running word recognition Long-term visual memory Visual attention Divided attention Immediate visual memory Mood evaluation
The study was double-blind, randomized, and crossover in design. Each subject received 25 mg alpidem, 50 mg alpidem, I mg lorazepam, or placebo at weekly intervals in identical capsules according to a latin square.
On the screening day, subjects received a medical and psychological examination and a 45-minute training session on the computerized tasks with items different from those used on the test days. On the four test days, substance intake was at 9.30 am. Two baseline blocks of computerized psychometrie testing were done before and seven blocks after medication (Table I). Item presentation and data collection were controlled by an IBM-compatible AT Pe.
±O
Drug Intake
+10 +10 +18 +22 +26 +30 +38 +40
Block 3 Running word recognition Long-term visual memory Visual attention Divided attention Immediate visual memory Mood evaluation Break
+50
Block 4 (same as block 3)
+90
Block 5 (same as block 3)
Treatment
Procedure
Tasks
+200
Standard lunch
+235
Block 8 (same as block 3)
Running word recognition. Five hundred nouns with a frequency of usage greater than I: 110,000 were selected from Meier (1964) and randomly allocated to a preliminary list and eight test lists. The 50 new words of each list were mixed with 50 old words from the preceeding list. Thus in each block, 100 words were presented visually (15 mm letters) and auditorily over headphones for a maximum of six seconds. The subjects' task was to classify each word as "old" (i.e., seen in the previous test block) or "new" (i.e., presented for the first time).
+275 +315
Block 9 (same as block 3) Side-effect evaluation Test behavior evaluation by research assistant
Tone discrimination. High (700 Hz) and low (300 Hz) tones with a duration of 250 ms and a ISI of 800 ms to 3000 ms were presented at an average ratio of 1:2. Subjects were instructed to press a button as soon as a high tone was heard.
+130 +130
Block 6 (same as block 3) Mood evaluation by research assistant
+170
Block 7 (same as block 3)
Learn trial
While Lister (1985), Curran (1986), Curran et al. (1987), Greenblatt et al. (1988), Lister et al. (1988), and Preston et al. (1988) have suggested that benzodiazepine-induced anterograde amnesia is primarily the consequence of benzodiazepines' global sedative action, Clarke et al. (1970), Sold et al. (1983), and Rodrigo & Lusiardo (1988) have proposed a specific benzodiazepine-induced encoding deficit. In order to further evaluate the specificity of benzodiazepine-induced memory impairment, four visual matching-to-sample tasks were constructed, dilTering solely in the length of the delay between presentation of a target stimulus and the appearance of four choice stimuli. The simultaneous presentation of the target stimulus and the choice stimuli was to measure attention only, while the delayed presentation required episodic memory as weil. The aims of the present study were therefore (I) to assess the degree of anterograde amnesia in young and elderly volunteers caused by alpidem as against lorazepam and placebo and (2) to determine the intluence of alpidem and lorazepam on similarly constructed visual attention and memory tasks.
Visual attention. Twenty-five parallel matching-tosampie tasks (8 x visual attention, 8 x divided visual attention, 9 x immediate visual memory), each consisting of 18 items, were constructed. Each item consisted of a target stimulus and a set of four simultaneously presented, numbered choice stimuli (one target stimulus and three distractors). Target stimuli consisted of motivating abstract and realistic colored pictures and the distractors differed from target stimuli to some degree in color, size, or content. Each item was presented on the screen for up to 20 seconds or until subjects pressed the correct button, whichever came first. Ifthe response was an error, the item remained on the screen and subjects could choose again. The 18 visual attention items consisted of a target stimulus in the left half of the screen and four choice stimuli on the right. Divided visual attention. Eighteen visual attention items were presented as the primary task. In addition, subjects simultaneously performed the tone discrimination task. Immediate visual memory (l5-second delayed recognition). Eighteen items were presented in the following manner: a target stimulus was shown for four seconds followed by 15 seconds of tone discrimination as distraction. Then the four choice stimuli were presented simultaneously and subjects were to press the corresponding button as soon as possible. Long-term visual memory (20-minute delayed recognition). The same 18 sets of choice stimuli from the immediate visual memory subtest were shown again in the following test block (approximately 20 minutes after their first presentation), and subjects were expected to recognize the target stimuli. The position of the target
Downloaded by: National University of Singapore. Copyrighted material.
Teble 1
115
W Satzger. R. R. Engel, E. Ferguson et al.
Pharmacopsychiatry 23 (1990)
Table 2 Means (sd) or frequencies of screening variables for young and older subjects with t-test comparisons (ss no. of correct responses, s = seconds) Biographical variables Females Males Weight (kg) Age (years) Years of education
Young subjects (n = 12)
Older subjects (n = 12)
7 5 69.7 24.1 14.5
(9.09) (3.27) (2.35)
7 5 75.2 68.3 11.8
114.26 112.50 114.75 11.8 12.5 11.7 10.4 13.0 14.2 12.0 11.0 12.7 11.2 12.8
(6.9) (7.0) (8.7) (1.40) (2.02) (3.04) (1.92) (1.16) (1.65) (2.98) (2.15) (1.65) (1.96) (0.93)
114.67 116.33 110.92 11.5 12.4 10.6 9.9 12.5 9.7 7.8 9.4 9.5 9.3 12.3
23.1 57.5 116.1 8.3 7.3 15.4 15.0
(8.88) (15.11) (13.33) (1.37) (2.57) (0.79) (1.04)
38.4 89.1 107.3 5.2 4.5 12.3 9.7
= scaled score, nc =
P
(11.42) (4.45) (2.65)
1.54 27.67 2.60
.137
.000 .016
WAlS Total 10 Verbal 10 Performance 10 Information (ss) Comprehension (ss) Digit Span (ss) Arithmetic (ss) Similarities (ss) Digit Symbol (ss) Picture Arrangement (ss) Picture Completion (ss) Block Design (ss) Object Assembly (ss) Vocabulary (ss)
(6.7) (9.2) (7.7) (2.23) (1.97) (2.70) (2.53) (1.67) (2.26) (1.40) (3.28) (1.88) (2.46) (1.61)
0.15 1.15 1.14 0.44 0.10 0.92 0.54 0.99 5.56 4.38 1.47 4.49 2.11 0.93
.883 .263
3.65 5.05 1.86 5.17 3.23 4.59 5.29
.001
.266 .666 .920 .367 .592 .333
.000 .000 .156
.000 .046
.364
Visual-motor and memory tests Trail making A (s) Trail making B (s) Letter cancellation test d2 (nc) Benton (nc) AVLT1 sI trial 1 (nc) AVLT5 1h trial (nc) AVLT6 1h trial (nc) 1Auditory
(11.47) (15.60) (9.61) (1.54) (1.44) (2.18) (3.27)
.000 .076
.000 .004 .000 .000
Verbal Learning Test (for all test citations see Lezak, 1983)
stimulus among the distractors was, however, changed in order to prevent simple position learning. Mood evaluation. Subjects rated their mood at the end of each test block and the research assistant rated subjects' mood 130 minutes post drug. Each of the 15 dimensions of the EWL-G (Rösler et a1., 1980) were transformed into seven-point rating scales and these items were presented with three further items (wakefulness, physical well-being, effectiveness). Additionally, the research assistant rated subjects' personality with the Nürnberger Alters Rating Scale (Oswald & Fleischman, 1986) and subjects' test behavior according to 11 criteria (understanding of test instructions, willingness to continue, interest in own performance, cooperation, carefulness, motivation, self-
