Between-group Differences In Performance Research Articles

Biomechanical load quantification of national and regional soccer players with an inertial sensor setup during a jump, kick, and sprint task: assessment of discriminative validity

Training load quantification methods may help optimize soccer performance. However, whole-body indicators potentially underestimate biomechanical load. A new inertial sensor setup allows joint-specific biomechanical load quantification. Good discriminative validity further supports the use of this method, and therefore the purpose of this study is to assess the discriminative validity of this method during soccer-specific activities. Twelve national and sixteen regional soccer players wore an inertial sensor setup and performed countermovement jumps, soccer kicks, and 30 m sprints. Between-group differences in angular acceleration-based biomechanical load indicators Knee Load, Hip Load, and performance were assessed using MANOVAs and Cohen’s effect sizes. Furthermore, relationships with performance were explored. National players showed higher Knee Load during jumping (mean difference: 0.11 A.U., ES = 0.93, p = 0.02), kicking (mean difference: 1.94 A.U., ES = 0.94; p = 0.02), and almost during sprinting (mean difference: 12.85, ES = 0.77; p = 0.05). Hip Load did not differ between groups across all tasks, although national players outperformed regional players on all tests. Significant relationships between Knee Load (rjump = 0.41, rkick = 0.65), Hip Load (rjump = 0.42), and performance were observed with 95% confidence intervals ranging from trivial to large. The results confirm discriminative validity of Knee Load for jumping and kicking, but not for sprinting and Hip Load in general. The confidence intervals of the established relationships suggest that the biomechanical loads might not entirely explain between-group differences in performance. The results can be used as reference values for biomechanical load quantification in the field.

To each their own: The different mechanisms underlying the effect of sex hormones on visuospatial and verbal abilities

As they easily access the brain, sex hormones are associated with cognitive functions such as visuospatial and verbal abilities. As oral contraceptive (OC) users, naturally cycling women (NC women; not using OC), and men exhibit distinct sex hormone profiles, between-group differences in visuospatial and verbal performance have been observed. To date, the mechanisms underlying these differences remain unknown. Acute levels of sex hormones are thought to have either a fostering or impairing effect on performance on these tasks (e.g., acute levels of testosterone and estradiol enhance and impair visuospatial skills, respectively). Moreover, preliminary results suggest a positive correlation between the duration of OC use and visuospatial performance. Thus, the objective of this study was to investigate the temporality of the effects of sex hormones on cognition (i.e., through rapid mechanisms, long-term mechanisms, or both). To do so, 201 healthy participants (70 OC, 86 NC, and 45 men) completed tests measuring their visuospatial and verbal fluency abilities. Analyses revealed that men outperformed both groups of women and that OC users outperformed NC women on the visuospatial task. Estradiol levels in men were associated with lower performance, whereas testosterone levels in OC users were related to better performance. Regarding verbal fluency, we found no between-group differences in performance or correlations with acute hormone levels. Interestingly, longer OC use was associated with better verbal fluency in OC users. In sum, acute hormone concentrations appear to modulate visuospatial performance, whereas long-term hormonal changes (i.e., OC use over years) seem to modulate verbal fluency abilities.

Reading and spelling profiles of adult poor readers: Phonological, orthographic and morphological considerations.

Reading and spelling skills are important to communicate in today's literate society, however, the underlying processes of spelling skills are under-researched compared to reading skills. Our goals were to (a) study how the component skills of phonological, orthographic and morphological awareness are different in adults with and without reading difficulties, and (b) characterize the relationship between the component skills and reading and spelling performance in both skilled and poor readers. Participants (N=37, N=15 with reading impairments and N=22 skilled readers) took part in the study where they completed several literacy-based measures. We performed a series of mixed ANOVAs to study the between-group differences in performance and the relationship between different literacy outcomes, respectively. We found evidence for poor phonological and morphological awareness in the poor readers compared to the skilled readers. We also found differential relationships between the component skills and reading and spelling behavior. Specifically, sound awareness was significantly related to reading and spelling measures in the skilled readers, whereas morphological and sound awareness played an important role in the same skills in the poor readers. We discuss these findings in the context of potential remediation strategies for adults with persistent literacy impairments.

Is processing speed a valid neurocognitive endophenotype in bipolar disorder? Evidence from a longitudinal, family study

BackgroundSubstantial evidence supports the existence of neurocognitive endophenotypes in bipolar disorder (BD), but very few longitudinal studies have included unaffected relatives. In a 5-year, follow-up, family study, we have recently suggested that deficits in manual motor speed and visual memory could be endophenotype candidates for BD. We aimed to explore whether this also applies to processing speed. MethodsA sample of 348 individuals, including 163 BD patients, 65 unaffected first-degree relatives (BD-Rel) and 120 genetically unrelated healthy controls (HC), was assessed with the Digit Symbol Substitution Test (DSST) on two occasions over a 2-year period (T1, T2). DSST values were controlled for age, years of education, occupational status, and subsyndromic mood symptoms. Differences between groups were evaluated with ANCOVAs. ResultsAt T1 BD performed significantly worse than HC (p < 0.001; Cohen's d = 1.38) and BD-Rel (p < 0.001; Cohen's d = 0.82). BD-Rel showed an intermediate performance with significant differences with HC (p < 0.01; Cohen's d = 0.50). Similarly, at T2 BD performed significantly worse than HC (p < 0.001; Cohen's d = 1.44) and BD-Rel (p < 0.01; Cohen's d = 0.51). BD-Rel performance was intermediate and significantly lower than that of HC (p < 0.01; Cohen's d = 0.97). A Repeated Measures ANOVA revealed no significant between-group differences in performance over time (p > 0.05). ConclusionsThe results of this longitudinal, family study suggest that impaired processing speed may represent a suitable cognitive endophenotype for BD. Further research on the field is required to confirm these preliminary findings.

Neurodevelopmental testing of mice in the neonatal period does not affect their locomotor activity, depressive- and anxiety-like behaviour in adolescence

Neonatal life is a sensitive period of brain plasticity. There are concerns that pre-weaning handling may therefore alter behavioural phenotype in adolescence or adulthood. Since neurodevelopment tests require daily manipulation with pups, later behavioural outcomes might be biased by repeated handling during suckling period. The aim of our study was to assess whether daily neurodevelopmental testing would cause alterations in behavioural phenotype. Sixty-four CD1 mice were randomized to tested and not tested group. In the tested group, maturation of physical features and neurodevelopment were monitored daily from postnatal day 1–21 between 9 and 11 AM. After weaning, battery of behavioural tests to monitor anxiety-like, depressive, or repetitive behaviour was performed in all mice. We revealed no significant between-group differences in performance of these tests. Our data did not confirm the assumption that early neurodevelopment testing during suckling period affects behavioural phenotype in adolescence.

A comparison of the performance of Persian speaking children who do and do not stutter on three nonwords repetition tasks

PurposeThe purpose of the study was to examine the performance of Persian speaking children who stutter (CWS) and children who do not stutter (CWNS) on three nonword repetition tasks, while also focusing on which task and scoring method best differentiates the two groups of children. MethodThirty CWS and 30 CWNS between the ages of 5;0 to 6;6 completed three nonword repetition tasks that varied in complexity. Each task was scored using two methods: nonwords correct and phonemes correct. Between-group differences in performance on each task were examined, along with disfluencies for CWS and the task and scoring method that best differentiated the CWS and CWNS. ResultsThe findings revealed that, across all three nonword repetition tasks, the CWS consistently produced fewer nonwords correct and phonemes correct than the CWNS group at virtually all syllable lengths. The CWS produced more disfluencies on longer nonwords than shorter nonwords in all three nonword repetition tasks. The nonword repetition task with lower wordlikeness and more phonologically complex items best differentiated the two groups of children. Findings further revealed that discriminative accuracy was highest for scoring based on the number of phonemes produced correctly. ConclusionFindings provide further evidence to suggest that CWS may have difficulty with phonological working memory and/or phonological processing.

Reply to Areta et al.: Time to withdraw and let the myth rest

Letter to the EditorReply to Areta et al.: Time to withdraw and let the myth restB. Gualano, L. d. S. Gonçalves, V. d. S. Painelli, G. Yamaguchi, L. F. de Oliveira, B. Saunders, R. P. da Silva, E. Maciel, G. G. Artioli, and H. RoschelB. GualanoUniversity of Sao Paulo, São Paulo, Brazil, L. d. S. GonçalvesUniversity of Sao Paulo, São Paulo, Brazil, V. d. S. PainelliUniversity of Sao Paulo, São Paulo, Brazil, G. YamaguchiUniversity of Sao Paulo, São Paulo, Brazil, L. F. de OliveiraUniversity of Sao Paulo, São Paulo, Brazil, B. SaundersUniversity of Sao Paulo, São Paulo, Brazil, R. P. da SilvaUniversity of Sao Paulo, São Paulo, Brazil, E. MacielUniversity of Sao Paulo, São Paulo, Brazil, G. G. ArtioliUniversity of Sao Paulo, São Paulo, Brazil, and H. RoschelUniversity of Sao Paulo, São Paulo, BrazilPublished Online:22 Nov 2017https://doi.org/10.1152/japplphysiol.00567.2017MoreSectionsPDF (30 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat to the editor: It is undisputable that caffeine variation in coffee—which is not as dramatic in Brazil as reported elsewhere (2)—is a potential bias pertaining to our, and any, study assessing its habitual dietary intake. In fact, such variability exists in any natural food due to differences in environment, genetics, and food processing. Therefore, if one is to take the point made by Areta et al. (1), the entire literature involving assessment of natural foods should be disregarded, which is obviously not the case. The suggestion that “reported caffeine intakes” could be verified through direct measurement of caffeine is, at least, curious; considering that caffeine half-life is ~5 h, it is puzzling how this measure could reflect one’s habitual caffeine consumption.Notably, we carefully assessed caffeine intake following Food and Drug Administration recommendations for high-quality food composition assessment. Briefly, caffeine intake was determined using a questionnaire adapted (and not replicated, as incorrectly assumed) from a validated instrument; the questionnaire was completed with the help of a qualified nutritionist who extracted as much detail and specific information as possible. Exact brands of products were identified to determine exact caffeine content. Although Areta et al. claimed that our dietary assessment was flawed, no scientific evidence was provided to support this assumption.We used a 24-h caffeine withdrawal to isolate the acute effect of supplementation from diet. Areta et al. argue that this influenced our results. Nonetheless, meta-analytical data show that caffeine withdrawal does not influence the ergogenic effect of caffeine (3). Indeed, caffeine consumption has previously been shown to be equally effective in habitual consumers following no, 2 days, and 4 days of withdrawal. In fact, some of the authors themselves have confirmed that a withdrawal period from dietary caffeine does not enhance or reduce the effect of an acute dose of caffeine on exercise performance. Thus we feel justified in our use of a withdrawal period to ensure rigorous control of our protocol.Although we acknowledge that our rationale regarding increased adenosine upregulation has been shown only in experimental (animal) models, which we drew attention to within the text, if true as hypothesized, 24-h withdrawal will not have led to any significant reduction herein and therefore will unlikely have influenced results.The criticism of our sample size is unfounded: 1) the lack of correlation between habitual intake and performance improvements was based on our entire sample; and 2) even when broken down to habitual intake, each tertile showed a greater number of subjects than in previous studies addressing this topic. Certainly, the numerous analyses performed in this study mitigate the odds of type-2 error.Since Areta et al. doubt our conclusions due to supposed inaccuracies in caffeine measurement, we provide a requiem to their uncertainties by reanalyzing all data following removal of coffee as the “less stable” source of caffeine, thus considering only other sources (e.g., cola drinks, tea, supplements). Only two participants moved between tertiles, which remained significantly different regarding intake (P < 0.0001). Neither significant between-group differences in performance (P = 0.81) nor correlation between habitual intake and performance changes (r = 0.00023; P = 0.92) was shown. Finally, when participants were distributed into quintiles, with the lower quintile consuming no coffee at all and the higher quintile consuming 6–8 coffees/day, differences in performance were still absent. These sensitivity analyses reinforce our original conclusion that habitual dietary caffeine does not affect the response to caffeine supplementation (4), putting this myth to rest.GRANTSThis work was supported by CAPES-PROEX.AUTHOR CONTRIBUTIONSL.d.S.G., V.d.S.P., B.S., and B.G. drafted manuscript; L.d.S.G., V.d.S.P., B.S., G.G.A., H.R., and B.G. edited and revised manuscript; L.d.S.G., V.d.S.P., G.Y., L.F.d.O., B.S., R.P.d.S., E.M., G.G.A., H.R., and B.G. approved final version of manuscript.DISCLOSURESNo conflicts of interest, financial or otherwise, are declared by the authors.

Explicit and Implicit Verbal Response Inhibition in Preschool-Age Children Who Stutter.

The purpose of this study was to examine (a) explicit and implicit verbal response inhibition in preschool children who do stutter (CWS) and do not stutter (CWNS) and (b) the relationship between response inhibition and language skills. Participants were 41 CWS and 41 CWNS between the ages of 3;1 and 6;1 (years;months). Explicit verbal response inhibition was measured using a computerized version of the grass-snow task (Carlson & Moses, 2001), and implicit verbal response inhibition was measured using the baa-meow task. Main dependent variables were reaction time and accuracy. The CWS were significantly less accurate than the CWNS on the implicit task, but not the explicit task. The CWS also exhibited slower reaction times than the CWNS on both tasks. Between-group differences in performance could not be attributed to working memory demands. Overall, children's performance on the inhibition tasks corresponded with parents' perceptions of their children's inhibition skills in daily life. CWS are less effective and efficient than CWNS in suppressing a dominant response while executing a conflicting response in the verbal domain.

Neural correlates of emotional response inhibition in obsessive-compulsive disorder: A preliminary study

Failure to inhibit recurrent anxiety-provoking thoughts is a central symptom of obsessive-compulsive disorder (OCD). Neuroimaging studies suggest inhibitory control and disgust processing abnormalities in patients with OCD. However, the emotional modulation of response inhibition deficits in OCD and their neural correlates remain to be elucidated. For this preliminary study we administered an adapted affective response inhibition paradigm, an emotional go/no-go task, during fMRI to characterize the neural systems underlying disgust-related and fear-related inhibition in nine adults with contamination-type OCD compared to ten matched healthy controls. Participants with OCD had significantly greater anterior insula cortex activation when inhibiting responses to both disgusting (bilateral), and fearful (right-sided) images, compared to healthy controls. They also had increased activation in several frontal, temporal, and parietal regions, but there was no evidence of amygdala activation in OCD or healthy participants and no significant between-group differences in performance on the emotion go/no-go task. The anterior insula appears to play a central role in the emotional modulation of response inhibition in contamination-type OCD to both fearful and disgusting images. The insula may serve as a potential treatment target for contamination-type OCD.

Speed of information processing in generally gifted and excelling-in-mathematics adolescents

A considerable amount of recent evidence suggests that speed of information processing (SIP) may be related to general giftedness as well as contributing to higher mathematical ability. To date, no study has examined SIP associated with both general giftedness (G) and excellence in mathematics (EM). This paper presents a part of more extensive research aimed at a multidimensional examination of mathematical giftedness, which is a complex function of the G factor and EM factor. The research population consisted of four groups of 10th–11th grade students who differed in their G level and EM level. 190 participants performed five SIP tests: Visual-matching, Cross-out of numbers, Digit-symbol, Symbol-search and Simple arithmetic exercises. We found that the G–EM group outperformed the three other study groups on all five tests. The findings reveal that between-group differences in performance on Cross-out of numbers and Simple arithmetic exercises tests are associated with both G and EM factors, whereas especially the G factor had an effect on students’ scores on Digit-symbol, Symbol-search and Visual-matching tests. In addition, we found gender differences on the Digit-symbol and Symbol-search tests. The results of this study suggest that EM and G factors are interrelated but represent different traits with respect to the SIP.

E-learning module on chronic low back pain in older adults: evidence of effect on medical student objective structured clinical examination performance.

The Institute of Medicine has highlighted the urgent need to close undergraduate and graduate educational gaps in treating pain. Chronic low back pain (CLBP) is one of the most common pain conditions, and older adults are particularly vulnerable to potential morbidities associated with misinformed treatment. An e-learning case-based interactive module was developed at the University of Pittsburgh Center of Excellence in Pain Education, one of 12 National Institutes of Health-designated centers, to teach students important principles for evaluating and managing CLBP in older adults. A team of six experts in education, information technology, pain management, and geriatrics developed the module. Teaching focused on common errors, interactivity, and expert modeling and feedback. The module mimicked a patient encounter using a standardized patient (the older adult with CLBP) and a pain expert (the patient provider). Twenty-eight medical students were not exposed to the module (Group 1) and 27 were exposed (Group 2). Their clinical skills in evaluating CLBP were assessed using an objective structured clinical examination (OSCE). Mean scores were 62.0 ± 8.6 for Group 1 and 79.5 ± 10.4 for Group 2 (P < .001). Using an OSCE pass-fail cutoff score of 60%, 17 of 28 Group 1 students (60.7%) and 26 of 27 Group 2 students (96.3%) passed. The CLBP OSCE was one of 10 OSCE stations in which students were tested at the end of a Combined Ambulatory Medicine and Pediatrics Clerkship. There were no between-group differences in performance on eight of the other nine OSCE stations. This module significantly improved medical student clinical skills in evaluating CLBP. Additional research is needed to ascertain the effect of e-learning modules on more-advanced learners and on improving the care of older adults with CLBP.

Explaining between-group differences in performance on timing tasks

The article discusses interpretation of between-group differences in performance on timing tasks. First, it is shown that differences in internal clock "pacemaker speed" cannot normally be used as a coherent explanation of obtained effects, even if such differences in pacemaker speed exist. Secondly, it is shown how, in theory, modelling of performance on commonly used timing tasks like bisection and temporal generalization can illuminate between-group effects. Thirdly, the article discusses some examples of such modelling from published work and shows how some between-group differences--for example, between children of different ages, or between patients and controls--have been explained. Finally, some ambiguities in modelling are discussed--for example, the fact that different explanations of differences in performance on timing tasks between groups may be difficult or impossible to distinguish in practice.

Beneficial Effect of N-acetylcysteine on Antineutrophil Cytoplasmic Antibody-associated Vasculitis

Although delusions are a frequent finding in patients with Alzheimer9s disease (AD), their mechanism is not well known. We carried out Tc 99m HMPAO single-photon emission computed tomography studies in 16 AD patients with delusions and 29 AD patients without delusions comparable in age, years of education, duration of illness, and severity of dementia. Although we found no significant between-group differences in performance on neuropsychological tasks, AD patients with delusions had significantly lower mean cerebral blood flow in both the left and right temporal lobes.

Performance of Patients Using Different Cochlear Implant Systems: Effects of Input Dynamic Range

To determine, for patients who had identical levels of performance on a monosyllabic word test presented in quiet, whether device differences would affect performance when tested with other materials and in other test conditions. For Experiment 1, from a test population of 76 patients, three groups (N = 13 in each group) were created. Patients in the first group used the CII Bionic Ear behind-the-ear (BTE) speech processor, patients in the second group used the Esprit3G BTE speech processor, and patients in the third group used the Tempo+ BTE speech processor. The patients in each group were matched on (i) monosyllabic word scores in quiet, (ii) age at testing, (iii) duration of deafness, and (iv) experience with their device. Performance of the three groups was compared on a battery of tests of speech understanding, voice discrimination, and melody recognition. In Experiments 2 (N = 10) and 3 (N = 10) the effects of increasing input dynamic range in the 3G and CII devices, respectively, was assessed with sentence material presented at conversational levels in quiet, conversational levels in noise, and soft levels in quiet. Experiment 1 revealed that patients fit with the CII processor achieved higher scores than Esprit3G and Tempo+ patients on tests of vowel recognition. CII and Tempo+ patients achieved higher scores than Esprit3G patients on difficult sentence material presented in noise at +10 and +5 dB SNR. CII patients achieved higher scores than Esprit3G patients on difficult sentence material presented at a soft level (54 dB SPL). Experiment 2 revealed that increasing input dynamic range in the Esprit3G device had (i) no effect at conversational levels in quiet, (ii) degraded performance in noise, and (iii) improved performance at soft levels. Experiment 3 revealed that increasing input dynamic range in the CII device improved performance in all conditions. Differences in implant design can affect patient performance, especially in difficult listening situations. Input dynamic range and the method by which compression is implemented appear to be the major factors that account for our results.

Polishing the Windows of the Mind

Polishing the Windows of the Mind

Mechanisms underlying age-related differences in ability to recover balance with the ankle strategy

Falls cause substantial death and morbidity in the elderly. An important prerequisite to the development of fall prevention interventions is improved understanding of the biomechanical and neuromuscular variables that govern ability to recover balance. In the present study, we examined the relative importance of strength versus speed of response variables in explaining differences in balance recovery performance with the ankle strategy between young and elderly women. Twenty-five young (19-36 years) and 25 community-dwelling elderly women (66-90 years) participated in balance recovery experiments. Subjects were supported in an inclined standing position by a horizontal tether and instructed to recover an upright vertical standing position by contracting their ankle muscles. The maximum initial lean angle from which they could recover balance without release of the tether (which depends primarily on strength) was 19.6% smaller for elderly than young. The maximum initial lean angle from which they could recover balance after the tether was suddenly released (which depends on both strength and speed of response) was 36.1% smaller for elderly than young. Moreover, between-group differences in performance were related to both strength and speed of response. Peak ankle torque was 7.7% smaller in elderly than young during dynamic recovery trials; reaction time was 27% slower in elderly, due to a lengthened muscle response latency, and rate of ankle torque generation was 15.6% slower in elderly. These results suggest that differences in ability to recover balance between young and elderly women associate with variables related to strength and speed of response, and that exercise-based fall prevention programs should include balance and agility training, in addition to strength training.

Performance of subjects fit with the Advanced Bionics CII and Nucleus 3G cochlear implant devices.

To determine if subjects who used different cochlear implant devices and who were matched on consonant-vowel-consonant (CNC) identification in quiet would show differences in performance on speech-based tests of spectral and temporal resolution, speech understanding in noise, or speech understanding at low sound levels. The performance of 15 subjects fit with the CII Bionic Ear System (CII Bionic Ear behind-the-ear speech processor with the Hi-Resolution sound processing strategy; Advanced Bionics Corporation) was compared with the performance of 15 subjects fit with the Nucleus 24 electrode array and ESPrit 3G behind-the-ear speech processor with the advanced combination encoder speech coding strategy (cochlear corporation). Thirty adults with late-onset deafness and above-average speech perception abilities who used cochlear implants. Vowel recognition, consonant recognition, sentences in quiet (74, 64, and 54 dB SPL [sound pressure level]) and in noise (+10 and +5 dB SNR [signal-to-noise ratio]), voice discrimination, and melody recognition. Group differences in performance were significant in 4 conditions: vowel identification, difficult sentence material at +5 dB and +10 dB SNR, and a measure that quantified performance in noise and low input levels relative to performance in quiet. We have identified tasks on which there are between-group differences in performance for subjects matched on CNC word scores in quiet. We suspect that the differences in performance are due to differences in signal processing. Our next goal is to uncover the signal processing attributes of the speech processors that are responsible for the differences in performance.

A SPECT study of delusions in Alzheimer's disease

Although delusions are a frequent finding in patients with Alzheimer's disease (AD), their mechanism is not well known. We carried out Tc 99m HMPAO single-photon emission computed tomography studies in 16 AD patients with delusions and 29 AD patients without delusions comparable in age, years of education, duration of illness, and severity of dementia. Although we found no significant between-group differences in performance on neuropsychological tasks, AD patients with delusions had significantly lower mean cerebral blood flow in both the left and right temporal lobes.

Taste detection and discrimination performance of rats following selective desalivation

Taste sensitivity and responsivity, two-tastant and taste-mixture discrimination performance, and taste preferences were examined prior to and after the selective desalivation of 48 male Long-Evans rats. Altered preference behavior was observed in rats after removal of the major salivary glands, as well as after removal of only the submandibular-sublingual complexes. In 9 of 12 desalivated rats, decreased sensitivity and increased responsivity to near-threshold sodium chloride solutions were observed, although these changes were less than one-half an order of magnitude. No between-group differences in performance on two-tastant and taste-mixuture discrimination tasks were observed. These results suggest that decrements in absolute sensitivity do not result in concomitant deficits in the discrimination of taste qualities.

Relationship Between Hyperglycemia and Cognitive Function in Older NIDDM Patients

The nature and extent of cognitive impairment was examined in 29 healthy elderly subjects (mean age 69.8 yr) with non-insulin-dependent diabetes mellitus (NIDDM) and 30 demographically similar nondiabetic community volunteers (mean age 68 yr). Measures of verbal learning, abstract reasoning, and complex psychomotor functioning were performed more poorly by diabetic than nondiabetic subjects. Conversely, there were no between-group differences in performance on tasks involving pure motor speed and simple verbal abilities. Within the diabetic group, individuals with poorer metabolic control performed more poorly on tasks involving learning, reasoning, and complex psychomotor performance, although this relationship was not evident for simple verbal or motor tasks. These data indicate that older people with NIDDM who are functioning well and perceive themselves as in good health are likely to manifest greater deficits than healthy elderly people in processing complex verbal or nonverbal material. Possible explanatory mechanisms are discussed, and directions for future research are explored.