The relation between response-specificity, S-R compatibility, foreperiod duration and muscle-tension in a target aiming task

Three experiments are reported aiming at a further understanding of the effect of response-specificity, operationalized as the degree of commonality of direction of movements. In a previous study, Spijkers (1987) has claimed that response-specificity affects the readiness of the motor system and is not related to response-selection processes. These suppositions were generally confirmed in experiments 1 and 2 respectively. Common to both experiments were the variables average movement velocity and response-specificity. In experiment 1 the effect of the additional variable foreperiod duration was found to interact with that of response-specificity, hereby confirming its expected relation to the muscular system. The effect of response-specificity did not interact with that of spatial S-R compatibility in the second experiment, but also failed to show a main effect. The third experiment examined the supposed relation of response-specificity more directly through manipulation of the muscle-tension of the responding limb. The predicted form of the interaction between the effect of response-specificity and muscle-tension was confirmed which provided additional evidence for the interpretation of response-specificity effects in terms of differential muscular activation.     

The representation and perception of 3D space: Interactions between 2D location and depth

ABSTRACT

We live in a 3D world, and yet the majority of vision research is restricted to 2D phenomena, with depth research typically treated as a separate field. Here we ask whether 2D spatial information and depth information interact to form neural representations of 3D space, and if so, what are the perceptual implications? Using fMRI and behavioural methods, we reveal that human visual cortex gradually transitions from 2D to 3D spatial representations, with depth information emerging later along the visual hierarchy, and demonstrate that 2D location holds a fundamentally special place in early visual processing.     

The relation between hand movements and intellectual activity in a skilled task

The experiment continues an investigation (Vince, 1953) into the relation between intellectual processes and hand movements in a sensori-motor task. Subjects were required to trace a repeating pattern of circles which appeared one, two or three at a time in a slit. Only one circle at a time could be hit and subjects were instructed to discover for themselves a good path for joining the maximum possible number of circles. The experimental situation thus allowed for various levels of response: pursuit movements, predictive movements, choice and a change of plan. At the end of the experiment subjects were asked to draw their idea of the pattern.

The results support others obtained earlier in showing that in this situation the subject's idea of the pattern he is tracing is determined by his total (motor, as well as visual) response to it. In addition, there was evidence that in some cases improvements occurred in the sensori-motor performance which were not reflected immediately in the subjects' idea of the pattern.     

The relation between angle of display and performance in a prolonged visual task

An experiment is described to test the relation between angle of display and performance in prolonged visual tasks, using the Clock Test in three positions of display surface, vertical, at an angle of 45 degrees to the horizontal, and horizontal. In every case the line of regard was kept at right-angles to the display surface. The results indicate that significantly fewer stimuli are missed in the vertical position of the display surface than in the other two.

The deterioration observed in the second half-hour of the original Clock Test experiments was not found in the present experiment, and two possible reasons for this are discussed briefly.     

A developmental study of the relationship between geometry and kinematics in drawing movements.

Trajectory and kinematics of drawing movements are mutually constrained by functional relationships that reduce the degrees of freedom of the hand-arm system. Previous investigations of these relationships are extended here by considering their development in children between 5 and 12 years of age. Performances in a simple motor task--the continuous tracing of elliptic trajectories--demonstrate that both the phenomenon of isochrony (increase of the average movement velocity with the linear extent of the trajectory) and the so-called two-thirds power law (relation between tangential velocity and curvature) are qualitatively present already at the age of 5. The quantitative aspects of these regularities evolve with age, however, and steady-state adult performance is not attained even by the oldest children. The power-law formalism developed in previous reports is generalized to encompass these developmental aspects of the control of movement.     

Plasticity of the association between visual space and action space in a blind-walking task

Many experiments have shown that a brief visual preview provides sufficient information to complete certain kinds of movements (reaching, grasping, and walking) with high precision. This suggests that participants must possess a calibration between visual target location and the kinaesthetic, proprioceptive, and/or vestibular stimulation generated during movement towards the target. We investigated the properties of this calibration using a cue-conflict paradigm in which participants were trained with mismatched locomotor and visual input. After training, participants were presented with visual targets and were asked to either walk to them or locate them in a spatial updating task. Our results showed that the training was sufficient to produce significant, systematic miscalibrations of the association between visual space and action space. These findings suggest that the association between action space and visual space is modifiable by experience. This plasticity could be either due to modification of a simple, task-specific sensory motor association or it could reflect a change in the gain of a path integration signal or a reorganisation of the relationship between perceived space and action space. We suggest further experiments that might help to distinguish between these possibilities.     

Models for response-response compatibility: The effects of the relation between responses in a choice task

A simple model is presented that consists of a stimulus-discrimination module and a motor-programming module. The motor-programming module is intended to account for RR-compatibility effects in different types of task. In combination with the stimulus-discrimination module, it is applied to a choice-RT task in which subjects have to perform rapid movements with the left or right hand in response to a left or right signal. The spatio-temporal patterns of the movements that have to be performed with the one or the other hand can be same or different. In the model the relation between the responses is mapped on the strength of inhibitory crosstalk between concurrent processes of motor programming. The stimulus-discrimination module implements a variant of an accumulator model or a random-walk model, and the transmission of information to the programming module can be continuous or discrete. Data that were generated by a model with discrete transmission were inconsistent with available experimental data. With continuous transmission, RR-compatibility effects can result from inhibitory crosstalk during concurrent processes of motor programming after presentation of the response signal and/or from the limiting effect of crosstalk on the level of pre-programming.     

An interactionist perspective on the relation between 2D:4D and behavior: An overview of (moderated) relationships between 2D:4D and economic decision making

The present paper gives an overview of recent research on the association between 2D:4D and different types of economic behavior. Particular attention is given to the importance of context dependence of relationships between 2D:4D and economic as well as other, social, behavior. Patterns of results are discussed from the perspective that 2D:4D might serve as a biological marker of dispositional dominance. This overview hopes to stimulate research from an interactionist perspective which focuses at relationships between 2D:4D and behavior that only appear when specific situational pressures interact with individual differences in 2D:4D.     

The effects of practice on limb kinematics in a throwing task

The effect of practice on limb kinematics in a dart-throwing task was examined to test three current hypotheses regarding limb control: trajectory formation; end-point control; and coordinated joint-space control. Practice was given to both the relatively well-practiced dominant ant the relatively unpracticed nondominant limbs of 5 male subjects to permit analysis of the early phase of coordination acquisition. The nondominant limb demonstrated high absolute joint cross-correlations with high variability throughout practice and consistency in the hand trajectory. The dominant limb exhibit a significant decrease in wrist-elbow and wrist-shoulder cross-correlations over practice while also maintaining a consistent hand trajectory and significantly higher scoring performance. The findings demonstrate that practice effects can be seen in both coordination mode and variability of various parameters of limb motion, but the changing relationship between the variables suggests that control cannot be ascribed to any one of the three hypotheses advanced. It is proposed that the observed invariance or variance in limb trajectories, end-point control, and coordinated joint angles are a reflection of more global parameters emerging from the flow field properties of the organism, environment, and task interaction.     

On the relation between transfer and difficulty of initial task

Subjects were required to throw at a target under three conditions of varying difficulty. Six groups of 14 subjects were used, each group receiving one of the six possible orders of presentation of the three conditions.

Results in terms of mean distance from the “bull” indicated that the three conditions were producing different transfer effects. These could not be adequately explained in terms of stimulus-or response-similarity, and accordingly a tentative hypothesis is put forward in terms of the relative difficulty of the condition presented first, to those presented subsequently. It is suggested that transfer tends to be positive from a relatively difficult initial task to a subsequent task which is easier, while transfer will tend to be negative from a relatively easy initial task to one which is more difficult.

The first of the three conditions presented exerted considerably more powerful transfer effects than the second. Three possibilities as to why this should be so, are outlined.     

The relation between off-job recovery and job resources: person-level differences and day-level dynamics

It is well-known that recovery from work and job resources can counteract negative effects of high job demands, but less is known about how off-job recovery and job resources are related to each other. In this two-level daily diary study, 67 employees filled out daily surveys over the course of 8 days to examine this issue. Consistent with our expectations, multilevel analyses revealed that previous day’s detachment from work is positively related to the state of being recovered before going to work, and that the state of being recovered is positively related to one’s level of job resources. Moreover, the results indicated that both person-level differences and day-level dynamics play a role in these relations. Our study highlights the importance of recovering from work in the sense that it does not only help individuals by repairing negative strain effects but can also function as a catalyst in the activation of job resources.     

Vocabulary and automatic attention: The relation between novel words and gaze dynamics in noun generalization

Words direct visual attention in infants, children, and adults, presumably by activating representations of referents that then direct attention to matching stimuli in the visual scene. Novel, unknown, words have also been shown to direct attention, likely via the activation of more general representations of naming events. To examine the critical issue of how novel words and visual attention interact to support word learning we coded frame-by-frame the gaze of 17- to 31-month-old children (n = 66, 38 females) while generalizing novel nouns. We replicate prior findings of more attention to shape when generalizing novel nouns, and a relation to vocabulary development. However, we also find that following a naming event, children who produce fewer nouns take longer to look at the objects they eventually select and make more transitions between objects before making a generalization decision. Children who produce more nouns look to the objects they eventually select more quickly following the naming event and make fewer looking transitions. We discuss these findings in the context of prior proposals regarding children's few-shot category learning, and a developmental cascade of multiple perceptual, cognitive, and word-learning processes that may operate in cases of both typical development and language delay.

Research Highlights

• Examined how novel words guide visual attention by coding frame-by-frame where children look when asked to generalize novel names.
• Gaze patterns differed with vocabulary size: children with smaller vocabularies attended to generalization targets more slowly and did more comparison than those with larger vocabularies.
• Demonstrates a relationship between vocabulary size and attention to object properties during naming.
• This work has implications for looking-based tests of early cognition, and our understanding of children's few-shot category learning.

     

Verbal representation in task order control: An examination with transition and task cues in random task switching

Recent task-switching studies in which a predictable task sequence has been used have indicated that verbal representation contributes to the control of task order information. The present study focused on the role of verbal representation in sequential task decisions, which are an important part of task order control, and examined the effects of articulatory suppression in a random-task-cuing paradigm with two different types of cues presented just before the presentation of a stimulus: a transition cue and a task cue. The former cue provided information only about switching or repeating the task, whereas the latter was associated directly with the identity of the task (i.e., indicating a parity or a magnitude task). In Experiment 1, in which transition cues guided task sequences, articulatory suppression impaired performance in both repetition and switch trials, thereby increasing the mixing costs. In Experiment 2, in which a task cue, rather than a transition cue, was presented to examine the influence of a cue-decoding process, articulatory suppression had no specific effect on task performance. Experiment 3, in which the transition cue and the task cue were randomly presented in the same block to equalize the memory load and task strategy for the two types of cues, confirmed that articulatory suppression significantly increased the mixing costs only in transition cue trials. The results from the three experiments indicated that the use of verbal representation is effective in sequential task decision—that is, in selecting a task set on the basis of transient task order information in both repetition and switch trials.     

The presence of aggression cues inverts the relation between digit ratio (2D:4D) and prosocial behaviour in a dictator game

Digit ratio (2D:4D) is a sexually dimorphic trait. Men have relatively shorter index (2D) compared to ring (4D) fingers than women. More masculine ratios are thought to be influenced by higher prenatal testosterone levels. In the present paper, we aim to show the context‐dependency of the relation between 2D:4D and social behaviour. In two studies, we expose participants either to control or to aggression cues. Afterwards, they make a decision in a dictator game. Participants with low 2D:4D showed higher allocation levels (i.e. they were more prosocial) than participants with high 2D:4D in a neutral situation. However, this relationship inverts after exposure to an aggression cue. It turns out that in high 2D:4D people, aggression cues even increase prosocial behaviour. We call for future research which focuses on other plausible interactions between 2D:4D and context cues rather than on linear relations.     

Changes with age and with exclusion of vision in performance at an aiming task

Forty industrial workers between 20 and 60 years of age took part in the experiment. Each sat facing a display in an enclosure. His task was to locate targets with a pointer, under two conditons: when he was able to make whatever use he chose of direct vision, and wearing a pair of red goggles through which only the diplay could be seen.

On the average, those over 40 years of age took more time than younger subjects over those portions of the task which were concerned with the initiation of a fresh action. V'hen unable t o make use of vision the older had far greater difficulty in locating the targets and attempted to supplement tactile and kinesthetic cues by making postural adjustments, turning their heads and often their bodies in the direction of the target at which they were aiming. These findings are discussed in relation to an earlier observation of the greater tendency for older people to look at what they are doing.     

Coordination dynamics of rhythmical and discrete prehension movements: Implications of the scanning procedure and individual differences

The aim of this study was to compare the coordination dynamics of discrete and rhythmical reaching and grasping movements from a dynamical systems perspective. Previous research from this theoretical perspective had focused on rhythmical actions and it is unclear to what extent discrete movements are amenable to a similar dynamical systems analysis. Six adult subjects performed prehension in two conditions: a discrete, non-continuous mode and a rhythmical, continuous mode. A `scanning procedure' was implemented between pre- and post-tests in which the required time of final relative hand closure (T_rfc) was systematically varied. It was shown that the error in the reaching and grasping pattern was least at an attractor region and systematically increased with deviation from the attractor. Results also indicated that there were no differences between condition or trial block for the group. However, there were several within-subject effects of interest. The validity of the scanning procedure was found to be questionable in the discrete condition, where four subjects showed differences in T_rfc between pre- or post-test and the predicted T_rfc of the scanning procedure. Four out of six subjects also had different preferred T_rfc values for discrete and rhythmical movement, indicating that individual specific models might need to be constructed for future dynamical modelling of discrete movement.PsycINFO classification: 2330