Attention and suppression affect tactile perception in reach-to-grasp movements

Reaching with the hand is characterized by a decrease in sensitivity to tactile stimuli presented to the moving hand. Here, we investigated whether tactile suppression can be canceled by attentional orienting. In a first experiment, participants performed a dual-task involving a goal-directed movement paired with the speeded detection of a tactile pulse. The pulse was either delivered to the moving or stationary hand, during movement preparation, execution, or the post-movement phase. Furthermore, stimulation was delivered with equal probability to either hand, or with a higher probability to either the moving or resting hand. The results highlighted faster RTs under conditions of higher probability of stimulation delivery to both moving and resting hands, thus indicating an attentional effect. For the motor preparation period, RTs were faster only at the resting hand under conditions where tactile stimulation was more likely to be delivered there. In a second experiment, a non-speeded perceptual task was used as a secondary task and tactile discrimination thresholds were recorded. Tactile stimulation was delivered concomitantly at both index fingers either in the movement preparation period (both before and after the selection of the movement effector had taken place), in the motor execution period, or, in a control condition, in the time-window of motor execution, but the movement of the hand was restrained. In the preparation period, tactile thresholds were comparable for the two timings of stimulation delivery; i.e., before and after the selection of the movement effector had taken place. These results therefore suggest that shortly prior to, and during, the execution of goal-directed movements, a combined facilitatory and inhibitory influence acts on tactile perception.     

Attention control in middle childhood: relations to psychopathological symptoms and threat perception distortions

The present study examined the construct of attention control, which is an important aspect of effortful control, in a sample of non-clinical children aged between 9 and 13 years. Results demonstrated that attention control was associated with a broad range of psychopathological complaints, including symptoms of anxiety, aggression, depression, and ADHD. As predicted, lower levels of attention control were accompanied by higher levels of these symptoms. Further, attention control was also negatively related to threat perception distortions, which indicates that children who display low levels of this regulative temperament factor are more prone to such cognitive biases. Third, when controlling for neuroticism, attention control remained significantly (negatively) associated with symptoms of anxiety, depression (child report only), and ADHD. The correlations between attention control and threat perception distortions largely disappeared when the influence of neuroticism was partialled out. Only the link between attention control and anxious interpretations of ambiguous vignettes survived this correction. Finally, no evidence was found for the hypothesised mediating role of cognitive distortions on the relation between temperament factors and psychopathological symptoms.