The Mechanics of Human Achievement

Countless studies have addressed why some individuals achieve more than others. Nevertheless, the psychology of achievement lacks a unifying conceptual framework for synthesizing these empirical insights. We propose organizing achievement‐related traits by two possible mechanisms of action: Traits that determine the rate at which an individual learns a skill are talent variables and can be distinguished conceptually from traits that determine the effort an individual puts forth. This approach takes inspiration from Newtonian mechanics: achievement is akin to distance traveled, effort to time, skill to speed, and talent to acceleration. A novel prediction from this model is that individual differences in effort (but not talent) influence achievement (but not skill) more substantially over longer (rather than shorter) time intervals. Conceptualizing skill as the multiplicative product of talent and effort, and achievement as the multiplicative product of skill and effort, advances similar, but less formal, propositions by several important earlier thinkers.     

Continuous visual control of interception

People generally try to keep their eyes on a moving target that they intend to catch or hit. In the present study we first examined how important it is to do so. We did this by designing two interception tasks that promote different eye movements. In both tasks it was important to be accurate relative to both the moving target and the static environment. We found that performance was more variable in relation to the structure that was not fixated. This suggests that the resolution of visual information that is gathered during the movement is important for continuously improving predictions about critical aspects of the task, such as anticipating where the target will be at some time in the future. If so, variability in performance should increase if the target briefly disappears from view just before being hit, even if the target moves completely predictably. We demonstrate that it does, indicating that new visual information is used to improve precision throughout the movement.     

Judgments of reachability are independent of visuomotor adaptation

The furthest distance that is judged to be reachable can change after participants have used a tool or if they are led to misjudge the position of their hand. Here we investigated how judged reachability changed when visual feedback about the hand was shifted. We hoped to distinguish between various ways in which visuomotor adaptation could influence judged reachability. Participants had to judge whether they could reach a virtual cube without actually doing so. They indicated whether they could reach this virtual cube by moving their hand. During these hand movements, visual feedback about the position of the hand was shifted in depth, either away from or toward the participant. Participants always adapted to the shifted feedback. In a session in which the hand movements in the presence of visual feedback were mainly in depth, perceived reachability shifted in accordance with the feedback (more distant cubes were judged to be reachable when feedback was shifted further away). In a second session in which the hand movements in the presence of visual feedback were mainly sideways, for some participants perceived reachability shifted in the opposite direction than we expected. The shift in perceived reachability was not correlated with the adaptation to the shift in visual feedback. We conclude that reachability judgments are not directly related to visuomotor adaptation.     

Conserving time in the classroom: the clicker technique

Any technique that conserves classroom instructional time without sacrificing the amount learned is of great educational value. This research compared a laboratory analogue of the clicker technique to analogues of other classroom pedagogical methods that all involve repeated testing during teaching. The clicker analogue mimics the classroom practice of dropping material that is understood by the majority of the class, as revealed by testing with clicker questions, from further lecture. A fact learning and retrieval paradigm was used, in which college students learned facts about unfamiliar countries. Compressing instruction time based on group-level performance produced as much learning as no compression and as compression based on individual-level performance. Results suggest that the clicker technique is an efficient and cost-effective method of conserving instructional time without loss of amount learned.     

Timing the moment of impact in fast human movements

The reported resolution of timing the moment of impact in fast human movements differs widely depending on the task. Surprisingly, better timing is reported for the demanding task of batting a ball than for the much simpler task of tapping in synchrony with two hands. We wondered whether this is because a sizeable part of timing variability arises from misjudging the distance in the direction of one's own movement, so that moving faster (as the bat does when moving toward a ball) improves timing. We found that moving faster does indeed improve timing in both the above-mentioned tasks. After removing the proposed contribution of misjudging the distance in the direction of one's own movement, we estimated that the remaining standard deviation in timing is just over 6ms for both tasks.     

Specificity and transfer effects in time production skill: examining the role of attention

Two experiments examined transfer of a prospective, time production skill under conditions involving changes in concurrent task requirements. Positive transfer of the time production skill might be expected only when the attentional demands of the concurrent task were held constant from training to test. However, some positive transfer was found even when the concurrent task at retraining was made either easier or more difficult than the concurrent task learned during training. The amount and direction of transfer depended more on the pacing of the stimuli in the secondary task than on the difficulty of the secondary task, even though difficulty affects attentional demands more. These findings are consistent with the procedural reinstatement principle of skill learning, by which transfer from one task to another depends on an overlap in procedures required by the two skills.     

Self-Report Measures to Identify Post Traumatic Stress Disorder and/or Mild Traumatic Brain Injury and Associated Symptoms in Military Veterans of Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF)

Individuals serving in Iraq and Afghanistan sustain injuries associated with physical and psychological trauma. Among such injuries, mild traumatic brain injury (mTBI) and post traumatic stress disorder (PTSD) are common. Self-report measures are frequently used to identify mTBI and/or PTSD and symptoms associated with these conditions. In addition to providing information regarding mTBI and PTSD, the goal of this literature review was to identify and present information on the psychometric properties of measures used to obtain information regarding these common conditions among Veterans who have returned from Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF). A comprehensive review of studies in which self-report measures were used to evaluate mTBI, PTSD, and associated symptoms among OEF/OIF Veterans is presented. Findings suggest that additional work is needed to identify psychometrically sound and clinically useful self-report measures that assess mTBI and PTSD and associated symptoms among OEF/OIF Veterans.