Vulnerability to the Irrelevant Sound Effect in Adult ADHD.

OBJECTIVE: An ecologically valid adaptation of the irrelevant sound effect paradigm was employed to examine the relative roles of short-term memory, selective attention, and sustained attention in ADHD. METHOD: In all, 32 adults with ADHD and 32 control participants completed a serial recall task in silence or while ignoring irrelevant background sound. RESULTS: Serial recall performance in adults with ADHD was reduced relative to controls in both conditions. The degree of interference due to irrelevant sound was greater for adults with ADHD. Furthermore, a positive correlation was observed between task performance under conditions of irrelevant sound and the extent of attentional problems reported by patients on a clinical symptom scale. CONCLUSION: The results demonstrate that adults with ADHD exhibit impaired short-term memory and a low resistance to distraction; however, their capacity for sustained attention is preserved as the impact of irrelevant sound diminished over the course of the task.

The comparison between motor imagery and verbal rehearsal on the learning of sequential movements.

Mental practice refers to the cognitive rehearsal of a physical activity. It is widely used by athletes to enhance their performance and its efficiency to help train motor function in people with physical disabilities is now recognized. Mental practice is generally based on motor imagery (MI), i.e., the conscious simulation of a movement without its actual execution. It may also be based on verbal rehearsal (VR), i.e., the silent rehearsal of the labels associated with an action. In this study, the effect of MI training or VR on the learning and retention of a foot-sequence task was investigated. Thirty right-footed subjects, aged between 22 and 37 years old (mean: 27.4 ± 4.1 years) and randomly assigned to one of three groups, practiced a serial reaction time task involving a sequence of three dorsiflexions and three plantar flexions with the left foot. One group (n = 10) mentally practiced the sequence with MI for 5 weeks, another group (n = 10) mentally practiced the sequence with VR of the foot positions for the same duration, and a control group (n = 10) did not practice the sequence mentally. The time to perform the practiced sequence as well as an unpracticed sequence was recorded before training, immediately after training and 6 months after training (retention). The main results showed that the speed improvement after training was significantly greater in the MI group compared to the control group and tended to be greater in the VR group compared to the control group. The improvement in performance did not differ in the MI and VR groups. At retention, however, no difference in response times was found among the three groups, indicating that the effect of mental practice did not last over a long period without training. Interestingly, this pattern of results was similar for the practiced and non-practiced sequence. Overall, these results suggest that both MI training and VR help to improve motor performance and that mental practice may induce non-specific effects.

Psychosocial and neurocognitive functioning in unipolar and bipolar depression: a 12-month prospective study.

Previous studies have revealed psychosocial and cognitive impairments in patients during unipolar and bipolar depression, which persist even in subsyndromal and euthymic states. Currently, little is known about the nature and the extent of psychosocial and cognitive deficits during depression. The aim of the present study was to characterize psychosocial and cognitive profiles among unipolar (MDD) and bipolar (BD) patients during a major depressive episode and to compare the profiles of the patient groups. Depressed patients with MDD (n=13) and BD (n=11) were followed over a period of 12 months. Clinical, psychosocial and neuropsychological assessments were conducted at baseline and at 6-week, 4-month, 8-month and 12-month follow-ups. In the case of severe mood disorders, psychosocial and neurocognitive functioning seem similar among MDD and BD patients during a depressive episode. All MDD and BD patients had global psychosocial dysfunction, characterized by occupational and relational impairments. Furthermore, the neurocognitive profile was heterogeneous with regard to the nature and extent of cognitive deficits but attentional processes were frequently compromised. After 1 year of treatment, occupational and relational impairments, as well as neurocognitive dysfunction, persisted sufficiently to alter daily functioning.

Psychosocial and neurocognitive profiles in depressed patients with major depressive disorder and bipolar disorder.

Previous studies have revealed psychosocial and cognitive impairments in patients during depression. The primary aim of this study was to investigate whether patients with major depression (MDD) and bipolar disorder (BD) differ in psychosocial and neurocognitive profiles. A second aim was to examine whether cognitive impairments are homogeneous among depressed patients. Patients with MDD (n=16) and BD (n=14) were enrolled during a major depressive episode. About half of them had comorbidities, including personality, substance use, and anxiety disorders. Information was collected about symptomatology and psychosocial functioning, whereas an exhaustive neuropsychological battery was administered to assess cognition. During a depressive episode, MDD and BD patients had global psychosocial dysfunction, characterized by occupational and relational impairments. A cognitive slowing was also observed, as well as deficits related to alertness, spontaneous flexibility, sustained and divided attention. Moreover, severity of depression and cognitive functions were significantly associated with psychosocial functioning. In the case of severe mood disorders, psychosocial and neurocognitive functioning seem similar among MDD and BD patients during a depressive episode. In addition to an altered daily functioning, the neurocognitive profile was heterogeneous with regard to the nature and extent of cognitive deficits. Executive functions, as well as verbal learning and memory, were preserved better than attentional processes.

The Kinesthetic and Visual Imagery Questionnaire (KVIQ) for assessing motor imagery in persons with physical disabilities: a reliability and construct validity study.

PURPOSE: To benefit from mental practice training after stroke, one must be able to engage in motor imagery, and thus reliable motor imagery assessment tools tailored to persons with sensorimotor impairments are needed. The aims of this study were to (1) examine the test-retest reliability of the Kinesthetic and Visual Imagery Questionnaire (KVIQ-20) and its short version (the KVIQ-10) in healthy subjects and subjects with stroke, (2) investigate the internal consistency of both KVIQ versions, and (3) explore the factorial structure of the two KVIQ versions. METHODS: The KVIQ assesses on a five-point ordinal scale the clarity of the image (visual: V subscale) and the intensity of the sensations (kinesthetic: K subscale) that the subjects are able to imagine from the first-person perspective. Nineteen persons who had sustained a stroke (CVA group) and 46 healthy persons (CTL group) including an age-matched (aCTL: n = 19) control group were assessed twice by the same examiner 10 to 14 days apart. The test-retest reliability was assessed using intraclass correlation coef- ficients (ICCs). The internal consistency (Cronbach alpha) and the factorial structure of both KVIQ versions were studied in a sample of 131 subjects. RESULTS: In the CVA group, the ICCs ranged from 0.81 to 0.90, from 0.73 to 0.86 in the aCTL group, and from 0.72 to 0.81 in the CTL group. When imagining movements of the affected and unaffected limbs (upper and lower limbs combined) ICCs in the CVA group ranged, respectively, from 0.71 to.87 and from 0.86 to 0.94. Likewise, when imagining movement of the dominant and nondominant limbs, ICCs in the aCTL group ranged, respectively, from 0.75 to 0.89 and from 0.81 to.92. Cronbach a values were, respectively, 0.94 (V) and 0.92 (K) for the KVIQ-20 and 0.89 (V) and 0.87(K) for the KVIQ-10. The factorial analyses indicated that two factors explained 63.4% and 67.7% of total variance, respectively. CONCLUSION: Both versions of the KVIQ present similar psychometric properties that support their use in healthy individuals and in persons post-stroke. Because the KVIQ-10 can be administered in half the time, however, it is a good choice when assessing persons with physical disabilities.

Functional cerebral reorganization following motor sequence learning through mental practice with motor imagery.

The goal of the present study was to examine, via positron emission tomography, the functional changes associated with the learning of a sequence of foot movements through mental practice with motor imagery (MI). Following intensive MI training over several days, which led to a modest but significant improvement in performance, healthy subjects showed an increase in activity restricted to the medial aspect of the orbitofrontal cortex (OFC), and a decrease in the cerebellum. These main results are largely consistent with those found in a previous study of sequence learning performed in our laboratory after physical practice of the same task [NeuroImage 16 (2002) 142]. Further analyses showed a positive correlation between the blood flow increase in the OFC and the percentage of improvement on the foot sequence task. Moreover, the increased involvement of the medial OFC revealed a modality specific anatomo-functional organization, as imagination of the sequential task after MI practice activated a more posterior region than its execution. These results demonstrate that learning a sequential motor task through motor imagery practice produces cerebral functional changes similar to those observed after physical practice of the same task. Moreover, the findings are in accord with the hypothesis that mental practice with MI, at least initially, improves performance by acting on the preparation and anticipation of movements rather than on execution per se.

Motor learning produces parallel dynamic functional changes during the execution and imagination of sequential foot movements.

The aim of the present positron emission tomography study was to measure the dynamic changes in cerebral activity before and after practice of an explicitly known sequence of foot movements when executed physically and to compare them to those elicited during motor imagery of the same movements. Nine healthy volunteers were scanned while performing both types of movement at an early phase of learning and after a 1-h training period of a sequence of dorsiflexions and plantarflexions with the left foot. These experimental conditions were compared directly, as well as to a perceptual control condition. Changes in regional cerebral blood flow associated with physical execution of the sequence early in the learning process were observed bilaterally in the dorsal premotor cortex and cerebellum, as well as in the left inferior parietal lobule. After training, however, most of these brain regions were no longer significantly activated, suggesting that they are critical for establishing the cognitive strategies and motor routines involved in executing sequential foot movements. By contrast, after practice, an increased level of activity was seen bilaterally in the medial orbitofrontal cortex and striatum, as well as in the left rostral portion of the anterior cingulate and a different region of the inferior parietal lobule, suggesting that these structures play an important role in the development of a long lasting representation of the sequence. Finally, as predicted, a similar pattern of dynamic changes was observed in both phases of learning during the motor imagery conditions. This last finding suggests that the cerebral plasticity occurring during the incremental acquisition of a motor sequence executed physically is reflected by the covert production of this skilled behavior using motor imagery.