Cognitive planning in manual action - action selection in multi-segment object manipulation tasks

Seegelke C. Cognitive planning in manual action - action selection in multi-segment object manipulation tasks. Bielefeld: Universität Bielefeld; 2014

Staggered onsets of processing relevant and irrelevant stimulus features produce different dynamics of congruency effects

The dynamics of congruency effects in conflict tasks can be analyzed by means of delta plots which depict the reaction-time differences between incongruent and congruent conditions across the quantiles of the reaction-time distributions. Delta plots exhibit a variety of different shapes. Here we test the hypothesis that staggered onsets of processing task-relevant and task-irrelevant features for response selection (together with a declining influence of the irrelevant feature) produce such variety. For this purpose, staggered onsets were implemented in two extensions of the Leaky, Competing Accumulator model. We show the cardinal capability of these models to produce different shapes of delta plots with different assumptions about temporal offsets between processing relevant and irrelevant stimulus features. Applying the models to experimental data, we first show that they can reproduce the delta plots observed with a conflict task with stimulus size as the irrelevant feature. For this task congruency effects are delayed and appear only at longer reaction times. Second, we fit the models to the results of two new Simon-task experiments with an experimentally controlled temporal offset in addition to the internal one. The experimentally induced variations of the shape of delta plots for this task could be reasonably well fitted by one of the two models that assumed an early start of response selection as soon as either the relevant or the irrelevant stimulus feature becomes available. We conclude that delta plots are crucially shaped by staggered onsets of processing relevant and irrelevant features for response selection

Simulating My Own or Others Action Plans? – Motor Representations, Not Visual Representations Are Recalled in Motor Memory

Seegelke C, Hughes CML, Schack T. Simulating My Own or Others Action Plans? – Motor Representations, Not Visual Representations Are Recalled in Motor Memory. PLoS ONE. 2013;8(12): e84662.Action plans are not generated from scratch for each movement, but features of recently generated plans are recalled for subsequent movements. This study investigated whether the observation of an action is sufficient to trigger plan recall processes. Participant dyads performed an object manipulation task in which one participant transported a plunger from an outer platform to a center platform of different heights (first move). Subsequently, either the same (intra-individual task condition) or the other participant (inter-individual task condition) returned the plunger to the outer platform (return moves). Grasp heights were inversely related to center target height and similar irrespective of direction (first vs. return move) and task condition (intra- vs. inter-individual). Moreover, participants' return move grasp heights were highly correlated with their own, but not with their partners' first move grasp heights. Our findings provide evidence that a simulated action plan resembles a plan of how the observer would execute that action (based on a motor representation) rather than a plan of the actually observed action (based on a visual representation)

Compatibility between object size and response side in grasping: the left hand prefers smaller objects, the right hand prefers larger objects

It has been proposed that the brain processes quantities such as space, size, number, and other magnitudes using a common neural metric, and that this common representation system reflects a direct link to motor control, because the integration of spatial, temporal, and other quantity-related information is fundamental for sensorimotor transformation processes. In the present study, we examined compatibility effects between physical stimulus size and spatial (response) location during a sensorimotor task. Participants reached and grasped for a small or large object with either their non-dominant left or their dominant right hand. Our results revealed that participants initiated left hand movements faster when grasping the small cube compared to the large cube, whereas they initiated right hand movements faster when grasping the large cube compared to the small cube. Moreover, the compatibility effect influenced the timing of grip aperture kinematics. These findings indicate that the interaction between object size and response hand affects the planning of grasping movements and supports the notion of a strong link between the cognitive representation of (object) size, spatial (response) parameters, and sensorimotor control

Anticipating different grips reduces bimanual end-state comfort. A tradeoff between goal-related and means-related planning processes

Seegelke C, Weigelt M. Anticipating different grips reduces bimanual end-state comfort. A tradeoff between goal-related and means-related planning processes. PLOS ONE. 2018;13(1): e0190586.The present study explored the sensitivity towards bimanual end-state comfort in a task that required anticipating different final grips. Participants simultaneously reached and grasped two objects with either a whole-hand grip (WHG) or a precision grip (PG), and placed them at two target locations by transporting them either over or under an obstacle. The transport path was varied such that it could be either congruent (i.e., both objects over or under) or incongruent (i.e., one object over and the other object under). In the congruent conditions, participants satisfied bimanual end-state comfort (and identical initial grips) on the majority of trials. That is, participants adopted a PG for either hand when the objects were transported over the obstacle and a WHG for either hand when the objects were transported under the obstacle. In contrast, in the incongruent conditions, bimanual end-state comfort was significantly reduced, indicating the presence of intermanual inference. The results indicate that goal-related planning constraints (i.e., bimanual end-state comfort) do not strictly take precedence over means-related constraints (i.e., identical initial grips) if this requires anticipating different final grips. Thus, bimanual end-state comfort per se does not provide a predominant constraint in action selection, by which sensorimotor interference can be reduced. In line with the proposal that bimanual grip planning relies on a flexible constraint hierarchy, a simple formal model that considers bimanual grip posture planning as a tradeoff between goal-related and means-related planning processes can explain our results reasonably well

Manual (a)symmetries in grasp posture planning: a short review

Seegelke C, Hughes CML, Schack T. Manual (a)symmetries in grasp posture planning: a short review. Frontiers in Psychology. 2014;5:1480.Many activities of daily living require that we physically interact with one or more objects. Object manipulation provides an intriguing domain in which the presence and extent of manual asymmetries can be studied on a motor planning and a motor execution level. In this literature review we present a state of the art for manual asymmetries at the level of motor planning during object manipulation. First, we introduce pioneering work on grasp posture planning. We then sketch the studies investigating the impact of future task demands during unimanual and bimanual object manipulation tasks in healthy adult populations. In sum, in contrast to motor execution, there is little evidence for hand-based performance differences in grasp posture planning. We discuss potential reasons for the lack of manual asymmetries in motor planning and outline potential avenues of future research

Compatibility between Physical Stimulus Size and Left-right Responses: Small is Left and Large is Right

According to a theory of magnitude (ATOM, Walsh, 2003, 2015), the cognitive representations of quantity, time, and space share a general magnitude code. Interestingly though, research has largely ignored the relationship between physical (stimulus) size and spatial (response) location. We conducted two experiments investigating compatibility effects between physical stimulus size and left-right responses. In both experiments, right-handed participants responded to a small or a large square stimulus by pressing a left or a right key. In Experiment 1, size was the relevant stimulus feature and we varied the S-R mapping within participants. Results revealed a strong compatibility effect: Performance was better with the compatible mapping (small-left and large-right) than with the incompatible mapping (large-left and small-right). In Experiment 2, participants responded to stimulus color, which varied independently of stimulus size, by pressing a left or right key. Results showed a congruency effect that mirrored the compatibility effect of Experiment 1. The results of our experiments suggest a strong relationship between the cognitive representation of physical (stimulus) size and response location in right-handers. The findings support the notion of a general magnitude code, as proposed in ATOM

Compatibility between object size and response side in grasping: the left hand prefers smaller objects, the right hand prefers larger objects

Seegelke C, Wühr P. Compatibility between object size and response side in grasping: the left hand prefers smaller objects, the right hand prefers larger objects. PeerJ. 2018;6: e6026.It has been proposed that the brain processes quantities such as space, size, number, and other magnitudes using a common neural metric, and that this common representation system reflects a direct link to motor control, because the integration of spatial, temporal, and other quantity-related information is fundamental for sensorimotor transformation processes. In the present study, we examined compatibility effects between physical stimulus size and spatial (response) location during a sensorimotor task. Participants reached and grasped for a small or large object with either their non-dominant left or their dominant right hand. Our results revealed that participants initiated left hand movements faster when grasping the small cube compared to the large cube, whereas they initiated right hand movements faster when grasping the large cube compared to the small cube. Moreover, the compatibility effect influenced the timing of grip aperture kinematics. These findings indicate that the interaction between object size and response hand affects the planning of grasping movements and supports the notion of a strong link between the cognitive representation of (object) size, spatial (response) parameters, and sensorimotor control

Cognitive Representation of Human Action: Theory, Applications, and Perspectives

Seegelke C, Schack T. Cognitive Representation of Human Action: Theory, Applications, and Perspectives. Frontiers in Public Health. 2016;4: 24.In this perspective article, we propose a cognitive architecture model of human action that stresses the importance of cognitive representations stored in long-term memory as reference structures underlying and guiding voluntary motor performance. We introduce an experimental approach to ascertain cognitive representation structures and provide evidence from a variety of different studies, ranging from basic research in manual action to application-oriented research, such as athlete performance and rehabilitation. As results from these studies strongly support the presence of functional links between cognitive and motor processes, we regard this approach as a suitable and valuable tool for a variety of different disciplines related to cognition and movement. We conclude this article by highlighting current advances in ongoing research projects aimed at improving interaction capabilities in technical systems, particularly for rehabilitation and everyday support of the elderly, and outline future research directions

Compatibility between physical stimulus size and left-right responses

According to a theory of magnitude (ATOM, Walsh, 2003, 2015), the cognitive representations of quantity, time, and space share a general magnitude code. Interestingly though, research has largely ignored the relationship between physical (stimulus) size and spatial (response) location. We conducted two experiments investigating compatibility effects between physical stimulus size and left-right responses. In both experiments, right-handed participants responded to a small or a large square stimulus by pressing a left or a right key. In Experiment 1, size was the relevant stimulus feature and we varied the S-R mapping within participants. Results revealed a strong compatibility effect: Performance was better with the compatible mapping (small-left and large-right) than with the incompatible mapping (large-left and small-right). In Experiment 2, participants responded to stimulus color, which varied independently of stimulus size, by pressing a left or right key. Results showed a congruency effect that mirrored the compatibility effect of Experiment 1. The results of our experiments suggest a strong relationship between the cognitive representation of physical (stimulus) size and response location in right-handers. The findings support the notion of a general magnitude code, as proposed in ATOM