Cited by 95Memory and Neural MechanismsMemory Processes and InfluencesMotor Control and Adaptation

The scope of preserved procedural memory in amnesia

Open access
Cavaco, S.·2004·Brain

Abstract

The finding that patients with amnesia retain the ability to learn certain procedural skills has provided compelling evidence of multiple memory systems in the human brain, but the scope, defining features and ecological significance of the preserved mnemonic abilities have not yet been explored. Here, we tested the hypothesis that subjects with amnesia would be able to learn and retain a broad range of procedural skills, by examining their acquisition and retention performance on five novel experimental tasks. The tasks are based on real-world activities and encompass a broad range of perceptual-motor demands: (i) the weaving task involves weaving pieces of fabric from woollen strings, using a manual weaver's loom; (ii) the geometric figures task consists of tracing geometric figures with a stylus as they move horizontally across a touch screen monitor; (iii) the control stick task involves tracking a sequence of visual target locations using a joystick control; (iv) the pouring task consists of pouring 200 ml of water from a watering can into a series of graduated cylinders, from a point 20 cm above the cylinders; and (v) the spatial sequence task involves learning an ordered sequence of pushing five spatially distributed buttons without visual guidance. Ten chronic and stable amnesic subjects (nine with bilateral medial temporal lobe damage due to herpes simplex encephalitis or anoxia, and one with thalamic stroke) and 25 matching normal comparison subjects were tested on…

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Crossref · 10.1093/brain/awh208

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Claims the paper makes

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  • Findingown data

    When baseline performance was taken into account, the amnesic and comparison groups had similar learning curves after the second trial on the weaving task (no significant learning x group interaction, F = 0.04, P = 0.84).

    “The analysis showed no significant learning  group interaction (F = 0.04, P = 0.84).This analysis demonstrates that when taking into account baseline performance, the amnesic and the comparison groups have similar learning curves after the second trial.”
    Quote in the paperSubstantial claim
  • Findingown data

    When baseline performance was taken into account, the amnesic and comparison groups had similar 24 h retention after the second trial on the weaving task (no significant retention x group interaction, F = 0, P = 1).

    “This analysis showed no significant retention  group interaction (F = 0, P = 1).This analysis demonstrates that when taking into account baseline performance, the amnesic and the comparison groups have similar retention after the second trial.”
    Quote in the paperSubstantial claim
  • Findingown data

    The comparison group did not show any significant reduction or increase in number of errors across trials.

    “The comparison group did not show any significant reduction or increase in number of errors across trials.”
    Quote in the paperNot a substantial claim
  • Findingown data

    No significant difference was found for the amnesic group between baseline and time 3 in number of errors.

    “No significant difference was found for the amnesic group between baseline and time 3.”
    Quote in the paperSubstantial claim
  • Findingown data

    The amnesics spent significantly more time performing the weaving task at baseline than comparison subjects (t = 4.83, P < 0.01).

    “The amnesics spent significantly more time (t = 4.83, P < 0.01) performing the task at baseline than comparison subjects.”
    Quote in the paperSubstantial claim
  • May combine two claims. 50
  • Classified as probably not a substantial claim. 34
  • The quote only partly states this claim. 3
  • May combine two claims.

    Findingown data

    At time 3, both amnesics (t = 3.08, P = 0.01) and comparison subjects (t = 2.82, P = 0.02) showed significant retention of the weaving skill.

    “At this follow-up, the amnesics (t = 3.08, P = 0.01) and the comparison subjects (t = 2.82, P = 0.02) showed significant retention of the weaving skill.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The hippocampus was particularly atrophic in the anoxic subjects.

    “The hippocampus was particularly atrophic in these anoxics.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The amnesic group reduced the number of errors from baseline to the last trial of time 1 (t = 3.47, P < 0.01), and from baseline to time 2 (t = 2.27, P = 0.05).

    “The amnesic group reduced the number of errors from baseline to the last trial of time 1 (t = 3.47, P < 0.01), and from baseline to time 2 (t = 2.27, P = 0.05).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The amnesic subjects' cognitive abilities were generally well-preserved, with the exception of severe memory impairment.

    “These findings show generally well-preserved cognitive abilities of these subjects, with the exception of their severe memory impairment (Tables 1 and 2).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The amnesics committed significantly more errors at baseline (t = 3.3, P < 0.01) and at the last trial of time 1 (t = 2.36, P < 0.05) than the comparison group.

    “The amnesics committed significantly more errors at baseline (t = 3.3, P < 0.01) and at the last (t = 2.36, P < 0.05) trial of time 1 than the comparison group.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The 2 x 2 ANOVA demonstrated a significant retention effect (F = 19.3, P < 0.01), significant group effect (F = 36.49, P < 0.01) and significant retention x group interaction (F = 4.94, P = 0.04) for the weaving task at time 3.

    “The 2  2 ANOVA demonstrated a significant retention effect (F = 19.3,P < 0.01), significant group effect (F = 36.49,P < 0.01) and significant retention  group interaction (F = 4.94, P = 0.04).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    At baseline, the frequency of errors ranged from 0 to 7 (mean = 3.4, SD = 2.8) for the amnesic group, and from 0 to 3 (mean = 0.48, SD = 0.82) for the comparison group.

    “At baseline, the frequency of errors ranged from 0 to 7 (mean = 3.4,SD = 2.8) for the amnesic group, and from 0 to 3 (mean = 0.48, SD = 0.82) for the comparison group.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Both amnesic and comparison groups significantly reduced the amount of time needed to perform the weaving task (amnesics t = 6.58, P < 0.01; comparison subjects t = 6.17, P < 0.01).

    “Both groups significantly reduced the amount of time needed to perform the task (amnesics t = 6.58,P < 0.01; comparison subjects t = 6.17,P < 0.01).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    No significant difference in number of errors was found between groups at time 2 (t = 2.14, P = 0.06) or time 3 (t = 2.05, P = 0.07).

    “No significant difference in number of errors was found between groups at time 2 (t = 2.14, P = 0.06) or time 3 (t = 2.05, P = 0.07).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    The mean interval between time 1 and time 3 was 85 days (SD = 51.8) for the amnesic group and 57 days (SD = 5.3) for the comparison group.

    “the mean interval between time 1 and time 3 for the qmnesic group was 85 days (SD = 51.8) and for the comparison group was 57 days (SD = 5.3)”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The 2 x 2 ANOVA showed significant retention effects (F = 78.07, P < 0.01), significant retention x group interaction (F = 10.77, P < 0.01), and significant group effects (F = 40.27, P < 0.01) for the weaving task.

    “The 2  2 ANOVA showed significant retention effects (F = 78.07,P < 0.01), significant retention  group interaction (F = 10.77,P < 0.01), and significant group effects (F = 40.27;P < 0.01).”
    Quote in the paperSubstantial claim
  • May combine two claims. The quote only partly states this claim.

    Findingown data

    When using ANOVA for repeated measures with baseline competency as covariate, the analyses showed no significant learning x aetiology effect for the HSE and anoxia groups.

    “When we used the ANOVA for repeated measures with trial 2 of time 1 as the first level of analyses, and baseline competency as the covariate, the analyses showed no significant learning  aetiology effect.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Both groups demonstrated learning on the geometric figures task (amnesics t = 3.6, P < 0.01; comparison subjects t = 3.31, P < 0.01).

    “Both groups demonstrated learning (amnesics t = 3.6, P < 0.01; comparison subjects t = 3.31, P < 0.01).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Multiple regression analyses revealed that age and education were not significant predictors of learning, retention at time 2, nor retention at time 3 of the geometric figures task, control stick task and spatial sequence task.

    “Multiple regression analyses revealed that age and education were not significant predictors of learning, retention at time 2, nor retention at time 3 of the geometric figures task, control stick task and spatial sequence task.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    After adjusting for age and education, the independent variable group was not a good predictor of learning, retention at time 2 nor retention at time 3 of any of the tasks.

    “After adjusting for these factors, the independent variable group was not a good predictor of learning, retention at time 2 nor retention at time 3 of any of the tasks.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Both groups demonstrated learning on the control stick task (amnesics t = 6.85, P < 0.01; comparison subjects t = 6.19, P < 0.01).

    “Both groups demonstrated learning (amnesics t = 6.85,P < 0.01; comparison subjects t = 6.19,P < 0.01).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    After adjusting for age and education, the independent variable group was a good predictor of learning (F = 2.98, P = 0.047) and retention at time 2 (F = 3.54, P = 0.03) of the weaving task.

    “After adjusting for these demographic factors, the independent variable group was a good predictor of learning (F = 2.98, P = 0.047) and retention at time 2 (F = 3.54, P = 0.03)”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The overall rate of false alarms per trial ranged between zero and eight in both amnesics and comparison groups.

    “The overall rate of false alarms per trial ranged between zero and eight in both amnesics and comparison groups.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    A 2 x 2 ANOVA showed significant learning effects (F = 67.42, P < 0.01), significant group effects (F = 6.23, P = 0.02) and no significant learning x group interaction (F = 1.39, P = 0.25) for the control stick task.

    “A 2  2 ANOVA showed significant learning effects (F = 67.42,P < 0.01), significant group effects (F = 6.23,P = 0.02) and no significant learning  group interaction (F = 1.39,P = 0.25).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Multiple regression analyses revealed that age and education were not significant predictors of learning (F = 0.18, P = 0.32), retention at time 2 (F = 0.02, P = 1) nor retention at time 3 (F = 0.99, P = 0.39) of the weaving task.

    “Multiple regression analyses revealed that age and education were not significant predictors of learning (F = 0.18, P = 0.32), retention at time 2 (F = 0.02, P = 1) nor retention at time 3 (F = 0.99, P = 0.39) of the weaving task.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    On tasks 2, 3, 4 and 5, no aetiology x learning interaction nor aetiology effect were found on the 2x2 ANOVA analyses.

    “On tasks 2, 3, 4 and 5, no aetiology  learning interaction nor aetiology effect were found on the 2  2 ANOVA analyses.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Both groups significantly increased the volume of water successfully poured (amnesics t = -2.79, P = 0.02; comparison subjects t = -4.5, P < 0.01).

    “Both groups significantly increased the volume of water successfully poured (amnesics t = À2.79,P = 0.02; comparison subjects t = À4.5, P < 0.01).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    At time 3, neither the amnesics (t = 0.35, P = 0.74) nor the comparison subjects (t = -1.93, P = 0.08) showed a significant difference from baseline.

    “At time 3, neither the amnesics (t = 0.35, P = 0.74) nor the comparison subjects (t = À1.93,P = 0.08) showed a significant difference from baseline.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The 2 x 2 ANOVA demonstrated a significant retention effect (F = 10.26, P < 0.01), no group effects (F = 1.92, P = 0.18) and no significant retention x group interaction (F = 0.34, P = 0.57) for the geometric figures task at time 3.

    “The 2  2 ANOVA demonstrated a significant retention effect (F = 10.26,P < 0.01), no group effects (F = 1.92,P = 0.18) and no significant retention  group interaction (F = 0.34, P = 0.57).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    A 2 x 2 ANOVA showed significant learning effects (F = 20.13, P < 0.01), significant group effects (F = 4.62, P = 0.04) and no significant learning x group interaction (F = 0.62, P = 0.44) for the geometric figures task.

    “A 2  2 ANOVA showed significant learning effects (F = 20.13,P < 0.01), significant group effects (F = 4.62, P = 0.04) and no significant learning  group interaction (F = 0.62, P = 0.44).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Significant learning was demonstrated by the comparison subjects (t = 7.02, P < 0.01) as well as the amnesics (t = 2.46, P = 0.04).

    “Significant learning was demonstrated by the comparison subjects (t = 7.02, P < 0.01) as well as the amnesics (t = 2.46, P = 0.04).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    One amnesic and one comparison subject were not able to perform a successful trial after 20 consecutive trials.

    “One amnesic and one comparison subject were not able to perform a successful trial after 20 consecutive trials.”
    Quote in the paperNot a substantial claim
  • The quote only partly states this claim.

    Findingown data

    The ANOVA for repeated measures with baseline competency as covariate showed no significant retention x group interaction (F = 0.69, P = 0.42) for the geometric figures task at time 3.

    “The ANOVA for repeated measures with trial 2 of time 1 and trial 1 of time 3 as the levels of analysis, and baseline competency as the covariate, showed no significant retention  group interaction (F = 0.69, P = 0.42).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    On paired-samples t tests, the 24 h retention level nearly reached significance for both the comparison group (t = 2.07, P = 0.05) and the amnesic group (t = 2.1, P = 0.06).

    “On t tests for paired samples, the retention level nearly reached significance for both the comparison group (t = 2.07, P = 0.05) and the amnesic group (t = 2.1, P = 0.06).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    An ANOVA for repeated measures with baseline competency as covariate showed no significant retention x group interaction at time 2 (F = 0.27, P = 0.6) or time 3 (F = 0.19, P = 0.67).

    “An ANOVA for repeated measures, with trial 2 of time 1 as the first level of analyses, and baseline competency as the covariate, showed no significant retention  group interaction at time 2 (F = 0.27, P = 0.6) or time 3 (F = 0.19, P = 0.67).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The 2 x 2 ANOVA showed significant retention effects (F = 13.17, P < 0.01), no significant group effects (F = 3.61, P = 0.07) and no significant retention x group interaction (F = 1.01, P = 0.32) for the geometric figures task.

    “The 2  2 ANOVA showed significant retention effects (F = 13.17,P < 0.01).This test did not show significant group effects (F = 3.61, P = 0.07) nor significant retention  group interaction (F = 1.01,P = 0.32).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    There were no significant differences between groups, or within groups over time, in the number of points available for sampling.

    “There were no significant differences between groups, or within groups over time in the number of points available for sampling.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The 24 h retention level of DFT reached significance for the amnesic group (t = 3.05, P = 0.01) and the comparison group (t = 2.38, P = 0.03).

    “On t tests for paired samples, the retention level of the DFT reached significance for the amnesic group (t = 3.05, P = 0.01) and the comparison group (t = 2.38, P = 0.03).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Amnesic subjects demonstrated more improvement across trials (at time 1) and better delayed retention (at times 2 and 3) than the non-amnesic subjects on the weaving task.

    “Amnesic subjects demonstrated more improvement across trials (at time 1) and better delayed retention (at times 2 and 3) than the non-amnesic subjects.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    Although the amnesic subjects demonstrated learning on all tasks, the delayed retention of the weaving skill and the ability to trace moving geometric figures contrasted with limited retention of the remaining skills.

    “Although the amnesic subjects demonstrated learning on all tasks, the delayed retention of the weaving skill and the ability to trace moving geometric figures contrasted with limited retention of the remaining skills.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Findingnone given

    The weaving task was completely novel to the subjects; no subject had prior experience operating a weaving loom, but most had some prior experience with apparatus such as a joystick, a watering can and a key pad.

    “First, this task was completely novel to the subjects.No subject had prior experience operating a weaving loom, but most had some prior experience with apparatus such as a joystick, a watering can and a key pad.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    The weaving task comprised the most complex routine of the five tasks, incorporating continuous ongoing feedback from the experimenter.

    “Secondly, the weaving task comprised the most complex routine of the five tasks, incorporating continuous ongoing feedback from the experimenter.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The weaving task required the coordinated use of both hands.

    “Thirdly, it required the coordinated use of both hands.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    At 24 h and 2 months retention periods, both amnesic and comparison groups showed remarkable retention of the weaving and geometric figures tasks, while on the spatial sequence task neither group showed any retention of the skill.

    “At 24 h and 2 months retention periods, both amnesic and comparison groups showed remarkable retention of the weaving and geometric figures tasks, while on the spatial sequence task neither group showed any retention of the skill.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The performances on the weaving task were significantly correlated with the Grooved Pegboard with both the dominant (Pearson's correlation = 0.655, P = 0.04) and the non-dominant hands (Pearson's correlation = 0.67, P = 0.03).

    “The performances on the weaving task were significantly correlated with the Grooved Pegboard with both the dominant (Pearson's correlation = 0.655, P = 0.04) and the non-dominant hands (Pearson's correlation = 0.67, P = 0.03).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingnone given

    While lesions in the anoxic subjects were limited to the hippocampus, all four HSE subjects had damage to the hippocampus, and three of the four had damage to the temporal poles, the amygdala, and the fourth and fifth temporal gyri (including entorhinal, parahippocampal and perirhinal cortices).

    “While lesions in the anoxic subjects were limited to the hippocampus, all four HSE subjects had damage to the hippocampus, and three of the four had damage to the temporal poles, the amygdala, and the fourth and fifth temporal gyri (including entorhinal, parahippocampal and perirhinal cortices).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingreasoning

    These two tasks presented the worst and the best retention results, respectively.

    “These two tasks presented the worst and the best retention results, respectively.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning

    Since some procedural memory systems are anatomically distinct from the declarative memory system, amnesic patients should be able to acquire skills with major implications for daily functioning.

    “Since some procedural memory systems are anatomically distinct from the declarative memory system, amnesic patients should be able to acquire skills with major implications for daily functioning.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    There was no significant difference between groups on the number of days interval between time 1 and time 3.

    “There was no significant difference between groups on the number of days interval between time 1 and time 3.”
    • Also stated in: § Number of points available · plain
      “There was no significant difference between groups on the number of days interval between time 1 and time 3.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    Inter-rater Pearson rs for tracing the amygdala and hippocampus were 0.917 for the left amygdala, 0.952 for the right amygdala, 0.93 for the left hippocampus, and 0.946 for the right hippocampus.

    “inter-rater Pearson rs were 0.917 for the left amygdala, 0.952 for the right amygdala, 0.93 for the left hippocampus and 0.946 for the right hippocampus.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    At time 3, complete data were only available for nine amnesics and 13 comparison subjects.

    “At time 3, complete data were only available for nine amnesics and 13 comparison subjects.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    The comparison group was matched to the amnesic group in terms of age and years of education.

    “The comparison group was matched to the amnesic group in terms of age (mean = 51.4years, SD = 15.4) and years of education (mean = 16 years, SD = 3.2).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The comparability of the tasks employed in this study with real-world activities highlights the potential application of this memory dissociation in the rehabilitation of patients with amnesia.

    “The comparability of the tasks employed in this study with real-world activities highlights the potential application of this memory dissociation in the rehabilitation of patients with amnesia.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    All amnesic patients were studied at least 5 months after their neurological event, at which time their neurological status and neuropsychological profiles were stable.

    “All were studied at least 5 months after their neurological event, at which time their neurological status and neuropsychological profiles were stable.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The primary inclusion criterion was the presence of amnesia, operationally defined as severe impairment on standardized measures of both verbal and visual memory (at least 1 Z-score below the mean on the 30 min delayed recall of both the Rey Auditory Verbal Learning Test and the Complex Figure Test).

    “The primary inclusion criterion was the presence of amnesia, which was operationally defined as severe impairment on standardized measures of both verbal and visual memory (at least 1 Z-score below the mean on the 30 min delayed recall of both the Rey Auditory Verbal Learning Test and the Complex Figure Test).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    The fact that the groups were not perfectly matched for age and education raised concerns regarding the interpretation of the results at time 3.

    “The fact that the groups were not perfectly matched for age and education raised concerns regarding the interpretation of the results at time 3.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The number of years of education and number of days interval between time 1 and time 3 did not differ significantly.

    “The number of years of education and number of days interval between time 1 and time 3 did not differ significantly.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The comparison group had significantly more years of education (mean = 18 years; SD = 3.3; t = -2.41, P = 0.02) than the amnesic group.

    “The comparison group had significantly more years of education (mean = 18 years; SD = 3.3; t = À2.41,P = 0.02) than the amnesic group.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The comparison group was significantly more educated than the amnesic group (t = -2.47, P = 0.02).

    “The comparison group was significantly more educated than the amnesic group (t = À2.47,P = 0.02).”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    At time 3, complete data were only available for 10 amnesics and 14 comparison subjects.

    “At time 3, complete data were only available for 10 amnesics and 14 comparison subjects.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    At time 3, the two groups were not significantly different in terms of age, years of education and days of interval between time 1 and time 3.

    “These two groups were not significantly different in terms of age, years of education and days of interval between time 1 and time 3.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    As a result of the reduction of the number of subjects, the groups were no longer matched for age.

    “As a result of the reduction of the number of subjects, the groups were no longer matched for age.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The comparison group was significantly younger (mean = 40.83 years; SD = 8.64; t = 2.67, P = 0.01) than the amnesic group.

    “The comparison group was significantly younger (mean = 40.83years; SD = 8.64; t = 2.67, P = 0.01) than the amnesic group.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    There was a tendency for the comparison group to be younger (mean = 42.4 years; SD = 9.1) than the amnesic group (t = 2.02, P = 0.05).

    “There was a tendency for the comparison group to be younger (mean = 42.4 years; SD = 9.1) than the amnesic group (t = 2.02, P = 0.05).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Study design and conductown data

    The two groups were not significantly different in terms of age nor on the number of days interval between time 1 and time 3.

    “The two groups were not significantly different in terms of age nor on the number of days interval between time 1 and time 3.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    At time 3, complete data were only available for nine amnesics and 12 comparison subjects.

    “At time 3, complete data were only available for nine amnesics and 12 comparison subjects.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). The quote only partly states this claim.

    Study design and conductown data

    At time 3, complete data were only available for nine amnesics and 10 comparison subjects on the geometric figures task.

    “At time 3, complete data were only available for nine amnesics and 10 comparison subjects.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Study design and conductown data

    When analyses for time 1 and time 2 were rerun with only those subjects who completed the protocol at time 3, the results were largely consistent with those previously presented: the groups' learning curves at time 1 continued to not differ for all tasks, and no significant retention x group interaction was found except for the pouring task.

    “We reran the analyses for time 1 and time 2 with only those subjects who completed the protocol at time 3.The results were largely consistent with those previously presented, i.e. the groups' learning curves at time 1 continued to not differ for all tasks, and no significant retention  group interaction was found except for the pouring task (Table 5).”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    At time 3, complete data were available for 10 amnesics and 16 comparison subjects.

    “At time 3, complete data were only available for 10 amnesics and 16 comparison subjects.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Our findings have significant implications for neurorehabilitation.

    “Finally, our findings have significant implications for neurorehabilitation.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Study design and conductreasoning

    We cannot eliminate any possibility of bias in these situations, given that amnesia of this level of severity is quite obvious.

    “We cannot eliminate any possibility of bias in these situations, given that amnesia of this level of severity is quite obvious.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The tendency for the HSE subgroup to perform better than the anoxic subjects on the weaving task raises the possibility that extensive bilateral lesions of the medial temporal region may actually 'facilitate' certain types of procedural learning by freeing them from declarative interference.

    “Therefore, the tendency for the HSE subgroup to perform better than the anoxic subjects on the weaving task raises the possibility that extensive bilateral lesions of the medial temporal region may actually 'facilitate' certain types of procedural learning by freeing them from declarative interference.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

    Interpretationcitation

    More practice and more spaced practice at time 1 might have resulted in better learning and retention of the skills.

    “More practice and more spaced practice at time 1 might have resulted in better learning and retention of the skills.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationown data

    Our results substantially extend the known scope of preserved procedural memory capacity in amnesia, and make clear that this preserved ability encompasses the acquisition of skills relevant to real-world activities.

    “Our results substantially extend the known scope of preserved procedural memory capacity in amnesia, and make clear that this preserved ability encompasses the acquisition of skills relevant to real-world activities.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    The ability of amnesic subjects to learn and retain a diverse set of new procedural skills with clear translation to real-world activities indicates that this is a robust phenomenon that probably is relevant to many aspects of daily living.

    “Rather, the ability of amnesic subjects to learn and retain a diverse set of new procedural skills with clear translation to real-world activities indicates that this is a robust phenomenon that probably is relevant to many aspects of daily living.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    In the weaving task, an unblinded examiner provided ongoing verbal correction of errors, raising the possibility of experimenter bias.

    “In the weaving task, an unblinded examiner provided ongoing verbal correction of errors, raising the possibility of experimenter bias.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Premisecitation

    Consolidation of a motor skill can be disrupted if a second motor task is learned immediately after the first, and the critical time window beyond which little or no interference is found from a competing task is approximately 4-5 h.

    “It has been shown that consolidation of a motor skill can be disrupted if a second motor task is learned immediately after the first, and the critical time window beyond which little or no interference is found from a competing task is $4-5 h (Brashers- Krug et al., 1996;Shadmehr and Brashers-Krug, 1997).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Brashers-Krug et al., 1996

      Not checked in the free run.

    • cites Shadmehr and Brashers-Krug, 1997

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    Procedural memory tasks relevant to real-world activities may facilitate the integration of amnesic subjects into the workplace, provided that a sheltered environment to compensate for impaired declarative recall can be established.

    “At the same time, procedural memory tasks relevant to real-world activities may facilitate the integration of amnesic subjects into the workplace, provided that a sheltered environment to compensate for impaired declarative recall can be established.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationown data

    The between-group differences in demographic factors, when they did occur, were always in the direction of being biased against our hypotheses, i.e. the comparison group was younger and more educated than the amnesic group.

    “The between-group differences in demographic factors, when they did occur, were always in the direction of being biased against our hypotheses, i.e. the comparison group was younger and more educated than the amnesic group.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationown data

    Our results help refine our understanding of the dissociation between declarative and procedural memory systems in the human brain.

    “Our results also help refine our understanding of the dissociation between declarative and procedural memory systems in the human brain.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The amount of practice and the practice schedule may influence learning and retention of perceptual-motor skills.

    “The amount of practice and the practice schedule may influence learning and retention of perceptual-motor skills (Schmidt and Lee, 1999).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Schmidt and Lee, 1999

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The finding that the amnesic group committed significantly more errors and that most of the comparison group performance was errorless argues against any bias in favour of the amnesic subjects.

    “argues against any bias in favour of the amnesic subjects.”
    Quote in the paperSubstantial claim
77 of 77
  • The paper relies on this without support.

    The scope and range of perceptual-motor skills that are preserved in amnesia remain largely unknown.

    “Thus, the scope and range of perceptual-motor skills that are preserved in amnesia remain largely unknown.”
  • The paper relies on this without support.

    The notion that procedural memory systems are anatomically distinct from declarative memory has had little impact on neurorehabilitation.

    “To date, however, this notion has had little impact on neurorehabilitation.”
  • The paper relies on this without support.

    The mirror tracing, rotor pursuit and serial reaction time tasks have a limited range of perceptual-motor requirements and no clear linkage to real-world activities.

    “The mirror tracing, rotor pursuit and serial reaction time tasks all allow careful experimental control, but have a limited range of perceptual-motor requirements and no clear linkage to real-world activities.”
  • The paper relies on this without support.

    To complete the tasks successfully, subjects need not recall, recognize or reflect on prior experiences.

    “To complete the tasks successfully, subjects need not recall, recognize or reflect on prior experiences.”
  • The paper relies on this without support.

    Memory impairments are among the most common consequences of injury to the brain.

    “Memory impairments are among the most common consequences of injury to the brain, and return to work is one of the most important rehabilitation goals of patients with brain injury.”
  • The paper relies on this without support.

    Return to work is one of the most important rehabilitation goals of patients with brain injury.

    “Memory impairments are among the most common consequences of injury to the brain, and return to work is one of the most important rehabilitation goals of patients with brain injury.”
  • The paper relies on this without support.

    Treatment options for memory impairments remain limited.

    “Unfortunately, treatment options for memory impairments remain limited.”
  • The paper relies on this without support.

    The approach of using non-declarative methods in clinical rehabilitation settings with amnesic patients remains largely unexplored.

    “Although there have been a few attempts to use non-declarative methods in clinical rehabilitation settings with amnesicpatients (e.g.Glisky et al., 1986;Zanetti et al., 1997;Goldstein et al., 1998;Suhr et al., 1999), this approach remains largely unexplored.”
  • The paper relies on this without support.

    The understanding of procedural learning in the normal population and in other brain-damaged populations is still very incomplete.

    “The understanding of procedural learning in the normal population and in other brain-damaged populations is still very incomplete.”
9 of 9

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Abstract claims retention of all five skills despite no spatial-sequence retention

    Major

    The abstract says the amnesic subjects retained all five skills, but the spatial-sequence results say neither group retained that skill at either follow-up.

  • Recognition questionnaire describes six performed tasks, not five

    Minor

    The methods describe five experimental tasks, but the recognition-test description says six different tasks in its questionnaire had been performed at time 1.

  • Two values reported for the geometric-figures retention statistic

    Minor

    The results give F = 10.26 for the time-3 geometric-figures retention effect, while Table 5 gives 10.16 for that effect.

3 of 3

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. [9]9. Doyon J, Ungerleider LG. Functional anatomy of motor skill learning. In: Squire LR and Schacter DL, editors. Neuropsychology of memory. 3rd edn, New York: Guilford Press; 2002. p. 225-38.
  2. [37]37. Krebs HI, Brashers-Krug T, Rauch SL, Savage CR, Hogan N, Rubin RH, et al. Robot-aided functional imaging: application to a motor learning study. Hum Brain Mapp 1998; 6: 59-72.

Cited by

Sorted by citations

Authors
Cavaco, S.
Affiliations
University of Iowa (US)
Corresponding author
Cavaco, S.
Venue
Brain
Published
2004-06-16
Volume
127
Issue
8
Pages
1853-1867
ISSN
  • 0006-8950 (ISSN-L)
  • 1460-2156
OpenAlex
W1997007945
Cited by
95
References
72
Citations by year
2025: 7 · 2024: 7 · 2023: 3 · 2022: 2 · 2021: 2 · 2020: 2 · 2019: 24 · 2018: 1 · 2017: 1 · 2016: 4 · 2015: 1 · 2014: 3 · 2013: 5 · 2012: 6
FWCI
1.69
Type
journal article
Language
en
Open access
Locations
  • Brain (publishedVersion)
  • PubMed (publishedVersion)
  • Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) (submittedVersion, other-oa)
Funders
National Institute of Neurological Disorders and Stroke (P01 NS19632, P01NS019632, NS-19632)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory and Neural Mechanisms
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory Processes and Influences
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Motor Control and Adaptation
Keywords
procedural memory, amnesia, multiple memory systems, perceptual-motor learning, skill acquisition, skill retention, herpes simplex encephalitis, thalamic infarction, memory dissociation, pouring task
MeSH terms
Adult, Age Factors, Aged, Amnesia, Chronic Disease, Educational Status, Female, Humans, Learning, Magnetic Resonance Imaging, Male, Middle Aged, Motor Skills, Neuropsychological Tests, Retention, Psychology

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

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