Chronometric Tests Research Articles

Gender Differences in Mental Rotation Across Adulthood

Although gender differences in mental rotation in younger adults are prominent in paper-pencil tests as well as in chronometric tests with polygons as stimuli, less is known about this topic in the older age ranges. Therefore, performance was assessed with the Mental Rotation Test (MRT) paper-pencil test as well as with a computer-based two-stimulus same-different task with polygons in a sample of 150 adults divided into three age groups, 20–30, 40–50, and 60–70 years. Performance decreased with age, and men outperformed women in all age groups. The gender effect decreased with age in the MRT, possibly due to a floor effect. Gender differences remained constant across age, however, in the error rates of the computer-based task.

Covert processing of words and pictures in nonsemantic variants of primary progressive aphasia.

The inability to name objects (anomia) is one of the most common findings in the neurologic examination of primary progressive aphasia (PPA). In the semantic variant of PPA, the anomia is profound and reflects a combination of object naming and word comprehension deficits. In contrast, nonsemantic variants of PPA display a more selective impairment of object naming, without corresponding impairments of word comprehension. The aim of the present study was to explore the nature of the anomia in nonsemantic variants of PPA with a sensitive chronometric test of covert word/picture association. We tested priming effects in 12 patients with nonsemantic variant of PPA and 18 controls. Stimuli consisted of written words and line pictures of concrete objects. Within-format (word-word and picture-picture) and cross-format (word-picture and picture-word) priming effects were assessed by measuring the shortening of response times to the second versus initial presentation of corresponding stimulus pairs. In addition to the expected impairment of picture-to-word priming, a condition simulating object naming, the nonsemantic PPA patients also showed unexpected impairments of word-to-picture and word-to-word priming. Picture-to-picture priming was preserved, demonstrating the selectivity of the deficit for lexical processing. These findings show that the information processing bottleneck in patients with nonsemantic variants of PPA is not confined to the stage of lexical access but that it also extends into the prior levels of lexical semantics. The boundaries between the semantic and nonsemantic variants are therefore far from rigid.

Reliability of Mental Chronometry for Assessing Motor Imagery Ability After Stroke

Malouin F, Richards CL, Durand A, Doyon J. Reliability of mental chronometry for assessing motor imagery ability after stroke. Objective To examine the reproducibility of 2 chronometric tests: time-dependent motor imagery (TDMI) screening test and temporal congruence test. Design Test-retest 10 to 14 days apart. Setting Laboratory of a university-affiliated center for research in rehabilitation. Participants Twenty persons post cerebrovascular accident (CVA) and 46 healthy persons (controls). Intervention The reproducibility of the TDMI screening test, wherein the number of stepping movements (performed in sitting) imagined over 15, 25, and 45 seconds is recorded, and of the temporal congruence test wherein the duration of physically executed (E) and imagined (I) stepping movements is recorded, was evaluated. Main Outcome Measures The test-retest reliability of the number of imagined movements (TDMI screening test), movement duration and I/E time ratios (temporal congruence test), and intrasession reliability of the temporal congruence test were assessed by using intraclass correlation coefficients (ICCs). Results For the TDMI screening test, the ICCs ranged from .88 to .93 (CVA, n=20) and from .87 to .92 (controls, n=9). For the temporal congruence test, when the total duration of 2 series of 5 stepping movements was averaged, ICCs ranged from .76 to .97 (CVA, n=20) and from .77 to .93 (controls, n=46), whereas for 1 series the ICCs ranged from .71 to .95 and from .63 to .95 in the CVA and control groups, respectively. The ICCs for intrasession reliability for the CVA (n=20) and control (n=46) groups, respectively, ranged from .90 to .98 and .95 to .97. Conclusions The present findings support the reproducibility of both tests in both groups. Mental chronometry can be used reliably for the screening of patients capable of motor imagery or for measuring temporal congruence between real and imagined movements poststroke.

Attention profile in schizophrenia compared with depression: differential effects of processing speed, selective attention and vigilance.

The aim of the study is to investigate whether subjects with schizophrenia and major depression display attention deficits for different reasons. Subjects with schizophrenia (n = 53), recurrent major depression (n = 50) and normal controls (n = 50) were administered with 11 measures of processing speed, selective attention and vigilance. Indices of basal speed, speeded attention, non-speeded attention and vigilance were computed. Both clinical groups were impaired on all chronometric tests. The schizophrenic subjects were also more impaired on speeded attention compared with basal processing speed. Only the schizophrenics were impaired on the non-speeded measures of selective attention. Compared with the schizophrenics, the depressives showed a decrement in vigilance. Reduced performance on attention tests in major depression is because of a non-specific speed reduction and loss of vigilance consistent with lack of effort. In addition to generally impaired processing speed, the schizophrenic subjects exposed a deficit in selective attention, indicating executive dysfunction.

Inspection time in the structure of cognitive abilities: Where does IT fit?

Inspection time (IT) correlates with IQ. This study had four aims: to locate IT within a hierarchical model of cognitive abilities; to test if IT has properties not tapped by other backward masking tasks; to test whether decision time (DT) from ‘odd-man-out’ (OMO) reaction time (RT) measures the same basic process as IT; and to test whether Wechsler performance IQ (PIQ) measures fluid ability (Gf). A battery of psychometric and chronometric tests was administered to 90 adults. Exploratory factor analysis showed that IT loaded on a general speediness factor and a higher-order general ability factor (G) but not on Gf. The results were similar for an alphanumeric pattern backward masking task suggesting that IT does not have special status as a backward masking task. DT and IT measured different processes and PIQ did not measure Gf. Confirmatory factor analyses compared results across alternative models of cognitive abilities but without differentiating one above the others. We conclude that IT does not measure fluid ability, but the question of whether information-processing speed is common to all cognitive abilities is still open.

Coexpression of tissue factor and tissue factor pathway inhibitor by human monocytes purified by leukapheresis and elutriation. Response of nonadherent cells to lipopolysaccharide.

Counterflow centrifugal elutriation is the method of choice for obtaining a large quantity of highly purified monocytes. In spite of the fact that this technique has been used for many years to isolate monocytes for cellular immunotherapy, it is not known whether the process of elutriation can stimulate tissue factor (TF) expression and therefore trigger coagulation in patients receiving these cell preparations. The aim of the present study is thus to identify TF and TF pathway inhibitor (TFPI) in elutriated monocytes and to evaluate their ability to trigger thrombin generation. Human monocytes are separated by leukapheresis and elutriation in sterile, endotoxin-free conditions. TF and TFPI mRNA is detected by reverse transcription-polymerase chain reaction. TF and TFPI are measured by enzyme-linked immunosorbent assay in cell lysates. TF antigen expression on cell surface is evidenced by direct-flow cytometry. Two functional tests (a chronometric test and an amidolytic assay) assess the capacity of monocytes to trigger thrombin generation. The response to lipopolysaccharide (LPS) is evaluated with each technique. Monocytic cell line THP-1 is used as a positive control. Elutriated monocytes coexpress TF mRNA and TFPI mRNA. The expression of TF mRNA is dramatically increased by LPS activation. This is correlated with a 100-fold increase in the amount of TF antigen in monocyte lysates. Flow immunocytometry confirms the expression of TF antigen on cell membrane in response to LPS stimulation, whereas TFPI mRNA is slightly increased after LPS stimulation. The amount of TFPI antigen in cell lysates is small when compared to that in plasma. Elutriated monocytes have a strong potential to trigger thrombin generation in response to LPS. In spite of the coexpression of TF mRNA and TFPI mRNA, elutriated monocytes are capable of supporting prothrombinase activity. This should be taken into account in the evaluation of the safety of adoptive cellular immunotherapy.

Normal intelligence with severe insulin-like growth factor I deficiency due to growth hormone receptor deficiency: a controlled study in a genetically homogeneous population.

Superior school performance was reported for 52 Ecuadorian probands with severe deficiency of insulin-like growth factor I (IGF-I) due to GH receptor deficiency (GHRD) resulting from homozygosity for the E180 splice mutation of the GHR. In contrast, subnormal intelligence was reported in a study of 18 genetically heterogeneous Israeli patients, attributed to frequent hypoglycemia or IGF-I dependence of brain development. This study is the first controlled evaluation of the intellectual ability of patients with GHRD. We compared the intelligence of 18 patients of school age (mean +/- SD age, 11.5 +/- 2.8 yr), 42 of their relatives (11.5 +/- 2.8 yr), and 28 community controls (10.0 +/- 0.8 yr), using a battery of intelligence tests that have been validated in cross-cultural research, designed to minimize the effects of physical size, motor coordination, and cultural background. Because all patients had the same GHR mutation, for which the carrier state could be determined, this study also investigated whether heterozygosity for mutation of the GHR among unaffected relatives is associated with intelligence. The intellectual ability of the patients with GHRD was not significantly different from that of their relatives (P > 0.05) on the psychometric tests of intelligence and was comparable to that of the community controls on the chronometric tests. Homozygosity or heterozygosity for the mutation in the GHR gene common to Ecuadorian patients was unrelated to intelligence (P > 0.05). These results indicate that the gene defect causing GHRD is not related to intelligence in the Ecuadorian population. They also indicate that GH-induced IGF-I production is not required for normal brain growth in utero or for postnatal intellectual development.

Elimination of Sat-Verbal Sex Differences Was Due to Policy-Guided Changes in Item Content

The content of the SAT-Verbal varies over time due to policy-driven manipulations. For this reason, using SAT-Verbal scores to study historical patterns in cognitive sex differences is not recommended. For such a purpose one is better served by the chronometric tests developed within the framework of cognitive psychology

Adapting Chronometric Tests for Field Studies of Cognitive Ability

Conclusions about group differences, especially sex differences, in cognitive ability have been based largely on psychometric tests, to the relative neglect of contemporary chronometric instruments. We explore some problems that may account for this methodological bias and suggest that the barriers to using chronometric techniques can be overcome. We adapted both the sentence-picture verification procedure and the Posner letter-matching task to field conditions, obtaining values in both instances which were virtually identical to those obtained under ideal laboratory conditions. 38 adults provided data for analysis.