How do we know what we are doing? Time, intention and awareness of action

Time is a fundamental dimension of consciousness. Many studies of the "sense of agency" have investigated whether we attribute actions to ourselves based on a conscious experience of intention occurring prior to action, or based on a reconstruction after the action itself has occurred. Here, we ask the same question about a lower level aspect of action experience, namely awareness of the detailed spatial form of a simple movement. Subjects reached for a target, which unpredictably jumped to the side on some trials. Participants (1) expressed their expectancy of a target shift during the upcoming movement, (2) pointed at the target as quickly and accurately as possible before returning to the start posiment to the target shift if required and (3) reproduced the spatial path of the movement they had just made, as accurately as possible, to give an indication of their awareness of the pointing movement. We analysed the spatial disparity between the initial and the reproduced movements on those with a target shift. A negative disparity value, or undershoot, suggests that motor awareness merely reflects a sluggish record of coordinated motor performance, while a positive value, or overshoot, suggests that participants' intention to point to the shifting target contributes more to their awareness of action than their actual pointing movement. Undershoot and overshoot thus measure the reconstructive (motoric) and the preconstuctive (intentional) aspects of action awareness, respectively. We found that trials on which subjects strongly expected a target shift showed greater overshoot and less undershoot than trials with lower expectancy. Conscious expectancy therefore strongly influences the experience of the detailed motor parameters of our actions. Further, a delay inserted either between the expectancy judgement and the pointing movement, or between the pointing movement and the reproduction of the movement, had no effect on visuomotor adjustment but strongly influenced action awareness. Delays during either interval boosted undershoots, suggesting increased reliance on a time-limited sensory memory for action. The experience of action is thus strongly influenced by prior thoughts and expectations, but only over a short time period. Thus, awareness of our actions is a dynamic and relatively flexible mixture of what we intend to do, and what our motor system actually does.     

Evaluating warning sound urgency with reaction times

It is well-established that subjective judgments of perceived urgency of alarm sounds can be affected by acoustic parameters. In this study, the authors investigated an objective measurement, the reaction time (RT), to test the effectiveness of temporal parameters of sounds in the context of warning sounds. Three experiments were performed using a RT paradigm, with two different concurrent visuomotor tracking tasks simulating driving conditions. Experiments 1 and 2 show that RT decreases as interonset interval (IOI) decreases, where IOI is defined as the time elapsed from the onset of one sound pulse to the onset of the next. Experiment 3 shows that temporal irregularity between pulses can capture a listener's attention. These findings lead to concrete recommendations: IOI can be used to modulate warning sound urgency; and temporal irregularity can provoke an arousal effect in listeners. The authors also argue that the RT paradigm provides a useful tool for clarifying some of the factors involved in alarm processing.     

Treatment effectiveness of combined medication/behavioural treatment with chinese ADHD children in routine practice

BACKGROUND: The effectiveness of a combined methylphenidate/behavioural treatment (BT) versus methylphenidate-only for Chinese children with Attention-Deficit/Hyperactivity Disorder (ADHD) was tested in routine clinical practice in Hong Kong. METHODS: A randomized group comparison design was adopted with two treatment conditions (methylphenidate-only; methylphenidate/BT), which lasted for 6 months. There were four assessment time points (pre-treatment, post-treatment, and 6-month and 12-month follow-ups), using the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviours (SWAN) Rating Scale. Parental attitude toward different treatment options of ADHD was also assessed at pre-treatment and post-treatment. Participants included 90 Chinese ADHD children (mean age=8 years, SD=.95). RESULTS: The combination of BT and a low-dose methylphenidate was significantly more effective than methylphenidate-only in reducing ADHD and ODD symptoms at post-treatment. At follow-ups, the benefits of the combined treatment were maintained, while the methylphenidate-only group caught up in improvement in ADHD symptoms. Parents in both treatment conditions showed improved attitude toward medication after the 6-month treatment phase, while their attitude toward BT was positive all along. CONCLUSIONS: This study supported the added benefits of BT, on top of medication, for Chinese ADHD children in routine practice with treatments conducted by regular medical and paramedical staffs.     

Envy,Facts and Justice: A Critique of the Treatment of Envy in Justice as Fairness

A common anti-egalitarian argument is that equality is motivated by envy, or the desire to placate envy. In order to avoid this charge, John Rawls explicitly banishes envy from his original position. This article argues that this is an inconsistent and untenable position for Rawls, as he treats envy as if it were a fact of human psychology and believes that principles of justice should be based on such facts. Therefore envy should be known about in the original position. The consequences for Rawlsian theory—both substantive and methodological—are discussed.

Investigating models of affect: relationships among EEG alpha asymmetry, depression, and anxiety

The approach-withdrawal and valence-arousal models both predict that depressive and anxious profiles will be associated with relatively reduced left frontal and increased right frontal activity respectively, while the valence-arousal model also proposes a dissociation by lower and higher right parietotemporal activity, respectively. Recent work further suggests that subtypes of anxiety disorders may be characterized by distinctive patterns of activity depending on their type of arousal (anxious arousal/apprehension). The aim of this study was to investigate the relationships among nonclinical depression/anxiety and lateralized frontal/parietotemporal activity by categorizing participants (N=428) on the basis of both negative mood and alpha EEG. Key findings include: (i) greater right frontal lateralization in anxious participants, symmetrical frontal activity in depressed/comorbid, and left frontal lateralization in healthy controls; (ii) right frontal lateralization in anxious arousal participants, left frontal and right parietotemporal lateralization in anxious apprehension; (iii) bilateral increase in frontal and increased right parietotemporal activity in depressed/comorbid participants. Findings support predictions for frontal but not posterior regions. Grouping on the basis of EEG may not be reciprocally predictive of negative mood groupings, suggesting involvement of additional factors.     

An R package for single-case randomization tests

Randomization tests are nonparametric statistical tests that obtain their validity by computationally mimicking the random assignment procedure that was used in the design phase of a study. Because randomization tests do not rely on a random sampling assumption, they can provide a better alternative than parametric statistical tests for analyzing data from single-case designs. In this article, an R package is described for use in designing single-case phase (AB, ABA, and ABAB) and alternation (completely randomized, alternating treatments, and randomized block) experiments, as well as for conducting statistical analyses on data gathered by means of such designs. The R code is presented in a step-by-step way, which at the same time clarifies the rationale behind single-case randomization tests.     

A camera-based scoring system for evaluating performance accuracy during a golf putting task

Golf putting accuracy is often evaluated by measuring the distance that the ball finishes from the hole. However, accuracy is a function of line and length, and distance-from-hole measures confound these two factors. A scoring system for evaluating putting accuracy is described that enables the efficient measurement of errors in line and length. A camera placed above the hole takes digital photographs of the final position of the ball. A custom-developed program written in the National Instruments LabVIEW graphical programming language derives a variety of accuracy measures from these photographs, including distance from the hole, angle of error, distance short or long from the hole, and distance left or right from the hole. Evaluation of the system indicated that the measures were as accurate as manual measurements and were reliable when rescored on separate occasions. The camera-based scoring system presents a number of advantages in the evaluation of putting accuracy and may be extended to examine performance in other sports. The ScorePutting program may be downloaded from the Psychonomic Society's Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.     

Age-of-acquisition and subjective frequency estimates for all generally known monosyllabic French words and their relation with other psycholinguistic variables

Ratings for age of acquisition (AoA) and subjective frequency were collected for the 1,493 monosyllabic French words that were most known to French students. AoA ratings were collected by asking participants to estimate in years the age at which they learned each word. Subjective frequency ratings were collected on a 7-point scale, ranging from never encountered to encountered several times daily. The results were analyzed to address the relationship between AoA and subjective frequency ratings with other psycholinguistic variables (objective frequency, imageability, number of letters, and number of orthographic neighbors). The results showed high reliability ratings with other databases. Supplementary materials for this study may be downloaded from the Psychonomic Society’s Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.     

Independent, synchronous access to color and motion features

We investigated the role of attention in pairing superimposed visual features. When moving dots alternate in color and in motion direction, reports of the perceived color and motion reveal an asynchrony: the most accurate reports occur when the motion change precedes the associated color change by approximately 100ms [Moutoussis, K., & Zeki, S. (1997). A direct demonstration of perceptual asynchrony in vision. Proceedings of the Royal Society of London B, 264, 393-399]. This feature binding asynchrony was probed by manipulating endogenous and exogenous attention. First, endogenous attention was manipulated by changing which feature dimension observers were instructed to attend to first. This yielded little effect on the asynchrony. Second, exogenous attention was manipulated by briefly presenting a ring around the target, cueing the report of the color and motion seen within the ring. This reduced or eliminated the apparent latency difference between color and motion. Accuracy was best predicted by timing of each feature relative to the cue rather than the timing of the two features relative to each other, suggesting independent attentional access to the two features with an exogenous attention cue. The timing of attentional cueing affected feature pairing reports as much as the timing of the features themselves.