Modeling the Effects of Attentional Cueing on Meditators.

Training in meditation has been shown to affect functioning of several attentional subsystems, most prominently conflict monitoring, and to some extent orienting. These previous findings described the effects of cueing and manipulating stimulus congruency on response times and accuracies. However, changes in accuracy and response times can arise from several factors. Computational process models can be used to distinguish different factors underlying changes in accuracy and response times. When decomposed by means of the drift diffusion model, a general process model of decision making that has been widely used, both the congruency and cueing effects, is subserved by a change in decision thresholds. Meditators showed a modest overall increase in their decision threshold, which may reflect an ability to wait longer and collect more information before responding.

On the Relationship Between the Practice of Mindfulness Meditation and Personality-an Exploratory Analysis of the Mediating Role of Mindfulness Skills.

Mindfulness meditation (MM) has often been suggested to induce fundamental changes in the way events in life are experienced and dealt with, presumably leading to alterations in personality. However, the relationship between the practice of MM and personality has not been systematically studied. The aim of this study was to explore this relationship and to investigate the mediating role of mindfulness skills. Thirty-five experienced mindfulness meditators (age range, 31-75 years; meditation experience range, 0.25-35 years; mean, ∼13 years) and 35 age-, gender-, and ethnicity-matched controls (age range, 27-63 years) without any meditation experience completed a personality (NEO-FFI) and mindfulness (KIMS) questionnaire. The practice of MM was positively related to openness and extraversion and negatively related to neuroticism and conscientiousness. Thus, the results of the current study associate the practice of MM with higher levels of curiosity and receptivity to new experiences and experience of positive affect and with less proneness toward negative emotions and worrying and a reduced focus on achievements. Furthermore, the mediating role of specific mindfulness skills in the relationship between the practice of MM and personality traits was shown.

Mindfulness meditation associated with alterations in bottom-up processing: psychophysiological evidence for reduced reactivity.

Mental training by meditation has been related to changes in high-level cognitive functions that involve top-down processing. The aim of this study was to investigate whether the practice of meditation is also related to alterations in low-level, bottom-up processing. Therefore, intersensory facilitation (IF) effects in a group of mindfulness meditators (MM) were compared to IF effects in an age- and gender-matched control group. Smaller and even absent IF effects were found in the MM group, which suggests that changes in bottom-up processing are associated with MM. Furthermore, reduced interference of a visual warning stimulus with the IF effects was found, which suggests an improved allocation of attentional resources in mindfulness meditators, even across modalities.

Greater efficiency in attentional processing related to mindfulness meditation.

In this study, attentional processing in relation to mindfulness meditation was investigated. Since recent studies have suggested that mindfulness meditation may induce improvements in attentional processing, we have tested 20 expert mindfulness meditators in the attention network test. Their performance was compared to that of 20 age- and gender-matched controls. In addition to attentional network analyses, overall attentional processing was analysed by means of efficiency scores (i.e., accuracy controlled for reaction time). Better orienting and executive attention (reflected by smaller differences in either reaction time or error score, respectively) were observed in the mindfulness meditation group. Furthermore, extensive mindfulness meditation appeared to be related to a reduction of the fraction of errors for responses with the same reaction time. These results provide new insights into differences in attentional processing related to mindfulness meditation and suggest the possibility of increasing the efficiency in attentional processing by extensive mental training.

Online maintenance of sensory and motor representations: effects on corticospinal excitability.

Flexible behavior requires the ability to delay a response until it is appropriate. This can be achieved by holding either a sensory or a motor representation online. Here we assess whether maintenance of sensory or motor material drives the motor system to different functional states, as indexed by alterations of corticospinal excitability. We used single-pulse TMS to measure corticospinal excitability evoked during the delay period of a novel paradigm in which task contingencies, rather than explicit verbal instructions, induced participants to use either sensory or motor codes to solve a delay-nonmatch-to-sample (DNMS) task. This approach allowed us to probe the state of the motor system while the participants were retaining either sensory or motor codes to cross the delay period, rather than the control of short-term storage driven by verbal instructions. When participants could prepare the movement in advance (preparation trials), the excitability of the motor cortex contralateral to the moving hand increased, whereas the excitability of the ipsilateral motor cortex decreased. The increase in excitability was confined to the prime mover, whereas the decrease in excitability extended to cortical territories controlling muscles unrelated to the response. Crucially, these changes in excitability were evoked only during preparation trials and not during trials in which subjects needed to maintain sensory items online (memory trials). We infer that short-term storage of sensory information and preparation of motor responses have differential and specific access to the output stage of the motor system.