Time for action versus action in time: time estimation differs between motor preparation and execution

Theories relating to time perception and motor performance predict very different temporal distortions depending on the synchronisation or succession of temporal processing and motor behaviour. However, our knowledge about the temporal difference between motor preparation and execution is still scarce. In order to expand on prior studies, two different time reproduction tasks were utilised to measure motor preparation and motor execution. We found that motor preparation of a planned action allows participants to complete the time reproduction task more accurately and, in short duration trials, less variably than for motor execution. Furthermore, under-reproduction was found in motor preparation compared to motor execution, which may be caused by increased temporal information processing. According to the attentional gate theory, more attention allocated to time processing and reduced motor distraction leads to less temporal distortion in the motor preparation. The findings are also important for designing to study consciousness, temporal and visual processing.     

The components of visual attention and the ubiquitous Simon effect

Spatial responding is influenced by the degree of correspondence between the stimulus–response (S–R) code activated by the target's task-irrelevant location and the S–R code activated by the target's non-spatial, task-relevant feature. A generally accepted explanation of this “Simon effect,” named after its discoverer, is that there is a natural tendency to respond towards the source of stimulation. First we will review the ubiquity of the Simon effect. Then we will review the literature, including our own studies when appropriate, that has explored the relationship between the Simon effect and the components of attention: alertness, orienting and executive control, with an emphasis on visual orienting. The Simon effect is reduced when participants are not alert and when executive control is effective in filtering out the irrelevant location information. When attention is oriented endogenously, or is captured exogenously by uninformative peripheral stimulation, the Simon effect is additive with attentional facilitation (i.e., the Simon effect is the same magnitude for targets presented at attended and unattended locations). Yet, some forms of orienting, such as orienting directed by gaze and biased by inhibition of return, modulate the Simon effect. We will explore the implications of these patterns of additivity and interaction for our understanding of both the Simon effect and spatial attention.     

The dual role of vision in sequential aiming movements

Previous research has demonstrated that movement times to the first target in sequential aiming movements are influenced by the properties of subsequent segments. Based on this finding, it has been proposed that individual segments are not controlled independently. The purpose of the current study was to investigate the role of visual feedback in the interaction between movement segments. In contrast to past research in which participants were instructed to minimize movement time, participants were set a criterion movement time and the resulting errors and limb trajectory kinematics were examined under vision and no vision conditions. Similar to single target movements, the results indicated that vision was used within each movement segment to correct errors in the limb trajectory. In mediating the transition between segments, visual feedback from the first movement segment was used to adjust the parameters of the second segment. Hence, increases in variability that occurred from the first to the second target in the no vision condition were curtailed when visual feedback was available. These results are discussed along the lines of the movement constraint and movement integration hypotheses.     

The influence of motor simulations on language comprehension

This study investigates the influence of activating specific motor codes on the comprehension of passages that describe the use of an object requiring similar motor manipulations. In three experiments, participants either imagined or pantomimed performing an action involving a common object. Participants then held the action in memory while reading a brief story, which described another object that required similar or different motor behaviors. Reading times were collected on the complementary actions. Finally, participants acted out the original action. In Exp. 1 and 2, reading slowed to the verbs. Exp. 2 revealed the slowing to be true interference, which disappeared in Exp. 3 when the action did not need to be recalled. The results suggest that readers activate motor codes when reading story actions, which supports an embodied view. The results also indicate that activated codes bound to an action will, at least briefly, impair reading about a complementary action requiring the same codes, consistent with Hommel's (2009) theory of event coding.     

Motor knowledge is one dimension for concept organization: Further evidence from a Chinese semantic dementia case

Neuropsychological and neuroimaging studies have indicated that motor knowledge is one potential dimension along which concepts are organized. Here we present further direct evidence for the effects of motor knowledge in accounting for categorical patterns across object domains (living vs. nonliving) and grammatical domains (nouns vs. verbs), as well as the integrity of other modality-specific knowledge (e.g., visual). We present a Chinese case, XRK, who suffered from semantic dementia with left temporal lobe atrophy. In naming and comprehension tasks, he performed better at nonliving items than at living items, and better at verbs than at nouns. Critically, multiple regression method revealed that these two categorical effects could be both accounted for by the charade rating, a continuous measurement of the significance of motor knowledge for a concept or a semantic feature. Furthermore, charade rating also predicted his performances on the generation frequency of semantic features of various modalities. These findings consolidate the significance of motor knowledge in conceptual organization and further highlights the interactions between different types of semantic knowledge.     

Literal, fictive and metaphorical motion sentences preserve the motion component of the verb: a TMS study

We used Transcranial Magnetic Stimulation (TMS) to assess whether reading literal, non-literal (i.e., metaphorical, idiomatic) and fictive motion sentences modulates the activity of the motor system. Sentences were divided into three segments visually presented one at a time: the noun phrase, the verb and the final part of the sentence. Single pulse-TMS was delivered at the end of the sentence over the leg motor area in the left hemisphere and motor evoked potentials (MEPs) were recorded from the right gastrocnemius and tibialis anterior muscles. MEPs were larger when participants were presented with literal, fictive and metaphorical motion sentences than with idiomatic motion or mental sentences. These results suggest that the excitability of the motor system is modulated by the motor component of the verb, which is preserved in fictive and metaphorical motion sentences.     

Intra-individual stability of neuromotor tasks from 6 to 18 years: a longitudinal study

This study investigates the intra-individual stability of the speed of several motor tasks and the intensity of associated movements in 256 children (131 girls, 125 boys) from the Zurich generational study using the Zurich neuromotor assessment battery (ZNA) over a 12-year period from the age of 6 to 18 years. The stability was assessed by correlograms of standard deviation scores calculated from age- and gender-adjusted normative values and compared with standing height and full scale intelligence quotient (IQ). While motor tasks of hand, finger and foot (HFT) and contralateral associated movements (CAM) exhibited a moderate stability (summary measure as correlation coefficients between two measurements made 4 years apart: .61 and .60), other tasks (dynamic balance, static balance and pegboard) were only weakly stable (.46, .47 and .49). IQ and height were more stable than neuromotor components (.72 and .86). We conclude that the moderately stable HFT and CAM may reflect “motor traits”, while the stability of the pegboard and balance tasks is weaker because these skills are more experience related and state-dependent.     

The development of temporal coordination in children

The ability to learn temporal patterns in sequenced actions was investigated in elementary-school age children. Temporal learning depends upon a process of integrating timing patterns with action sequences. Children ages 6-13 and young adults performed a serial response time task in which a response and a timing sequence were presented repeatedly in a phase-matched manner, allowing for integrative learning. The degree of integrative learning was measured as the slowing in performance that resulted when phase-shifting the sequences. Learning was similar for the children and adults on average but increased with age for the children. Executive function measured by Wisconsin Card Sorting Test (WCST) performance as well as a measure of response speed also improved with age. Finally, WCST performance and response speed predicted temporal learning. Taken together, the results indicate that temporal learning continues to develop in pre-adolescents and that maturing executive function or processing speed may play an important role in acquiring temporal patterns in sequenced actions and the development of this ability.     

Assessing motor proficiency in young adults: The Bruininks Oseretsky Test-2 Short Form and the McCarron Assessment of Neuromuscular Development

Currently, only two motor tests have norms extending into young adulthood – the McCarron Assessment of Neuromuscular Development (MAND, McCarron 1997) and the Bruininks Oseretsky Test of Motor Proficiency-2 (BOT-2, Bruininks & Bruininks, 2005). Research into the motor difficulties in early adulthood and health outcomes has been impeded because there is no agreed gold standard motor test for this group. The purposes of this study were to compare the discrimination accuracy, classification agreement, and predictive values, and gender distribution and prevalence of each test in identifying motor impairment (MI) in relation to DSM-V diagnostic criteria for DCD. Ninety-one young, healthy adults (M = 21.4 years, SD = 3.3) were recruited. Those classified as MI by each test scored at one standard deviation or more below the overall mean standard score. Small, statistically significant correlations were found between the MAND and BOT-2 SF tests for score rank (r = 0.370, p = 0.01) and standard score values (r = 0.404; p = 0.01). The overall decision agreement for non-MI cases was relatively high at 85% but very low for MI cases (4.4%). Unexpectedly, gender was balanced in MI cases. BOT-2 SF identified twice as many MI cases than MAND (13.2% vs 6.6%), yet overall comparative test specificity was high (89%). Predictive values for MAND, compared against BOT-2 SF as the standard, indicated broad independence between these tests and overall, the decision statistics indicated that the two tests identified different adult cohorts with MI. Objective classification of adult motor proficiency using a gold standard assessment tool including complex and ecologically valid tasks is still elusive.     

Children benefit differently from night- and day-time sleep in motor learning

Motor skill acquisition occurs while practicing (on-line) and when asleep or awake (off-line). However, developmental questions still remain about whether children of various ages benefit similarly or differentially from night- and day-time sleeping. The likely circadian effects (time-of-day) and the possible between-test-interference (order effects) associated with children's off-line motor learning are currently unknown. Therefore, this study examines the contributions of over-night sleeping and mid-day napping to procedural skill learning. One hundred and eight children were instructed to practice a finger sequence task using computer keyboards. After an equivalent 11-h interval in one of the three states (sleep, nap, wakefulness), children performed the same sequence in retention tests and a novel sequence in transfer tests. Changes in the movement time and sequence accuracy were evaluated between ages (6–7, 8–9, 10–11 years) during practice, and from skill training to retrievals across three states. Results suggest that night-time sleeping and day-time napping improved the tapping speed, especially for the 6-year-olds. The circadian factor did not affect off-line motor learning in children. The interference between the two counter-balanced retrieval tests was not found for the off-line motor learning. This research offers possible evidence about the age-related motor learning characteristics in children and a potential means for enhancing developmental motor skills. The dynamics between age, experience, memory formation, and the theoretical implications of motor skill acquisition are discussed.