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The cognitive system selects the most appropriate action imitative process: a semantic process – relying on long-term memory representations for known actions, and low-level visuomotor transformations for unknown actions. These two processes work in parallel; however, how context regularities and cognitive control modulate them is unclear. In this study, process selection was triggered contextually by presenting mixed known and new actions in predictable or unpredictable lists, while a cue on the forthcoming action triggered top-down control. Known were imitated faster than the new actions in the predictable lists only. Accuracy was higher and reaction times faster in the uncued conditions, and the predictable faster than the unpredictable list in the uncued condition only. In the latter condition, contextual factors modulate process selection, as participants use statistical regularities to perform the task at best. With the cue, the cognitive system tries to control response selection, resulting in more errors and longer reaction times. [ABSTRACT FROM AUTHOR]

Objective: To investigate how two types of body representation (body schema and body image) were affected in people with and without apraxia following a supratentorial stroke. Design: Observational cross-sectional study Setting: Level 1 Specialist Neurological Rehabilitation Unit Participants: 30 participants post-stroke diagnosed with (n = 10) and without apraxia (n = 20) according to a modified version of the short Ideomotor Apraxia Test. Interventions: Not applicable Main Outcome Measures: Body schema assessed using the hand laterality recognition test and body part knowledge test; Implicit body image assessed using the sidedness test. Results: Left-sided lesions were more common in the apraxic group. Compared to people without apraxia post-stroke, those with apraxia showed significantly reduced accuracy and longer reaction times on the hand laterality test and fewer correct responses on the body part knowledge test. There was no between-groups difference in the sidedness test. Conclusions: People with apraxia showed deficits in online body representations (body schema) that are used to plan and execute actions. Future research studies could target body schema deficits as an adjunct in the rehabilitation of apraxia. [ABSTRACT FROM AUTHOR]

Objective: To explore the relationship between laterality recognition after stroke and impairments in attention, 3D object rotation and functional ability. Design: Observational cross-sectional study. Setting: Acute care teaching hospital. Participants: Thirty-two acute and sub-acute people with stroke and 36 healthy, age-matched controls. Main outcome measures: Laterality recognition, attention and mental rotation of objects. Within the stroke group, the relationship between laterality recognition and functional ability, neglect, hemianopia and dyspraxia were further explored. Results: People with stroke were significantly less accurate (69% vs 80%) and showed delayed reaction times (3.0 vs 1.9 seconds) when determining the laterality of a pictured hand. Deficits either in accuracy or reaction times were seen in 53% of people with stroke. The accuracy of laterality recognition was associated with reduced functional ability (R2 = 0.21), less accurate mental rotation of objects (R2 = 0.20) and dyspraxia (p = 0.03). Conclusion: Implicit motor imagery is affected in a significant number of patients after stroke with these deficits related to lesions to the motor networks as well as other deficits seen after stroke. This research provides new insights into how laterality recognition is related to a number of other deficits after stroke, including the mental rotation of 3D objects, attention and dyspraxia. Further research is required to determine if treatment programmes can improve deficits in laterality recognition and impact functional outcomes after stroke. [ABSTRACT FROM AUTHOR]

When two athletes meet inside the ropes of the boxing ring to fight, their cognitive systems have to respond as quickly as possible to a manifold of stimuli to assure victory. In the present work, we studied the pre-attentive mechanisms, which form the basis of an athlete’s ability in reacting to an opponent’s punches. Expert boxers, beginner boxers and people with no experience of boxing performed a Simon-like task where they judged the colour of the boxing gloves worn by athletes in attack postures by pressing two lateralised keys. Although participants were not instructed to pay attention to the direction of the punches, beginner boxers’ responses resembled a defence-related pattern, expert boxers’ resembled counterattacks, whereas non-athletes’ responses were not influenced by the unrelated task information. Results are discussed in the light of an expertise-related action simulation account. [ABSTRACT FROM PUBLISHER]