Alexandra Lenhard

Movements or targets: What makes an action in action-effect learning?

According to ideomotor theory, actions become linked to the sensory feedback they contingently produce, so that anticipating the feedback automatically evokes the action it typically results from. Numerous recent studies have provided evidence in favour of such action–effect learning but left an important issue unresolved. It remains unspecified to what extent action–effect learning is based on associating effect-representations to representations of the performed movements or to representations of the targets at which the behaviour aimed at. Two experiments were designed to clarify this issue. In an acquisition phase, participants learned the contingency between key presses and effect tones. In a following test phase, key–effect and movement–effect relations were orthogonally assessed by changing the hand–key mapping for one half of the participants. Experiment 1 showed precedence for target–effect over movement–effect learning in a forced-choice RT task. In Experiment 2, target–effect learning was also shown to influence the outcome of response selection in a free-choice task. Altogether, the data indicate that both movement–effect and target–effect associations contribute to the formation of action–effect linkages—provided that movements and targets are likewise contingently related to the effects.

Explorations of anticipatory behavioral control (ABC): a report from the cognitive psychology unit of the University of Würzburg

The report comprises recent theoretical considerations, experimental research, and simulations which all aim at a clarification of anticipatory mechanisms of behavioral control.

Constant error in aiming movements without visual feedback is higher in the preferred hand

There is convincing evidence for a left hand advantage for the spatial planning of aiming movements in right-handers. However, little is known about equivalent proficiency in left-handers. Therefore, 48 participants (24 right-handers and 24 left-handers) performed aiming movements of the hand without visual feedback. While the variable aiming error tended to be lower for the preferred hand, the constant aiming error was consistently lower for the non-preferred hand. Data are consistent with the idea of a spatial accuracy advantage for the controller of the non-preferred hand. Data from an ambidextrous participant suggest that this functional difference might be innate rather than acquired through practice.

Spekulationen zur Strukturideo-motorischer Beziehungen

Zusammenfassung. Nach der ideo-motorischen Hypothese werden Aktionen mit ihren kontingenten sensorischen Effekten bidirektional verbunden, so dass eine Antizipation der Effekte direkt die Aktionen aktiviert, die erfahrungsgemas das Antizipierte hervorbringen. Wir diskutieren (1) die Rolle von exterozeptiven und propriozeptiven Effekten, (2) die Situationsabhangigkeit von Aktions-Effekt Beziehungen, (3) die Notwendigkeit abstrakter effektorunspezifischer Aktionsreprasentationen und schlieslich (4) die Verwertung von sensorischen Ruckmeldungen bei der Kontrolle der Aktionsausfuhrung. Unsere Diskussion fuhrt zu einer hypothetischen Struktur ideo-motorischer Beziehungen, in der die “Idee” (das antizipierte Ziel) die “Motorik” (die Korperbewegung) uber eine Kaskade von inversen Modellen determiniert.

Psychology has to deal with efferences too.

Abstract The authors argue that F. Mechsners (2004) perceptual-cognitive approach is an important contribution to the current discussion of motor control. Mechsner presents convincing evidence against direct motor control. Nevertheless, the mechanisms by which perceptual-cognitive representations determine efferent commands must still be clarified.

Equivalence of Screen Versus Print Reading Comprehension Depends on Task Complexity and Proficiency

ABSTRACT As reading and reading assessment become increasingly implemented on electronic devices, the question arises whether reading on screen is comparable with reading on paper. To examine potential differences, we studied reading processes on different proficiency and complexity levels. Specifically, we used data from the standardization sample of the German reading comprehension test ELFE II (n = 2,807), which assesses reading at word, sentence, and text level with separate speeded subtests. Children from grades 1 to 6 completed either a test version on paper or via computer under time constraints. In general, children in the screen condition worked faster but at the expense of accuracy. This difference was more pronounced for younger children and at the word level. Based on our results, we suggest that remedial education and interventions for younger children using computer-based approaches should likewise foster speed and accuracy in a balanced way.

Emergent Effector-Independent Internal Spaces: Adaptation and Intermanual Learning Transfer in Humans and Neural Networks

Psychological studies have shown immense behavioral flexibility in arm reaching tasks. Intermanual learning transfer (ILT) tasks have shown that both reaching movements adapt to distorted spaces rather rapidly and the adaptation generalizes to the behavior of other limbs. In this paper, we present an ILT experiment and replicate it with feedforward neural network (NN) architectures. We show that the NN architecture is the key to successfully replicating the experiments. Moreover, we show that dependent on the architecture and the initial training schedule applied, an internal space representation emerges that enables ILT. The results confirm that internal body spaces, identified in neuroscience and cognitive psychological research, can emerge solely due to an interdependence between different limb movements and the right neural architecture. We hypothesize that, in order to develop internal spatial representations observed in animals and humans, it might be sufficient to enforce the integration of multiple correlated sensory and motor information into one compact internal representation.

A Continuous Solution to the Norming Problem.

Conventional methods for producing test norms are often plagued with “jumps” or “gaps” (i.e., discontinuities) in norm tables and low confidence for assessing extreme scores. We propose a new approach for producing continuous test norms to address these problems that also has the added advantage of not requiring assumptions about the distribution of the raw data: Norm values are established from raw data by modeling the latter ones as a function of both percentile scores and an explanatory variable (e.g., age). The proposed method appears to minimize bias arising from sampling and measurement error, while handling marked deviations from normality—such as are commonplace in clinical samples. In addition to step-by-step instructions in how to apply this method, we demonstrate its advantages over conventional discrete norming procedures using norming data from two different psychometric tests, employing either age norms (N = 3,555) or grade norms (N = 1,400).