Forthcoming Actions Research Articles

Human volition: towards a neuroscience of will

The capacity for voluntary action is seen as essential to human nature. Yet neuroscience and behaviourist psychology have traditionally dismissed the topic as unscientific, perhaps because the mechanisms that cause actions have long been unclear. However, new research has identified networks of brain areas, including the pre-supplementary motor area, the anterior prefrontal cortex and the parietal cortex, that underlie voluntary action. These areas generate information for forthcoming actions, and also cause the distinctive conscious experience of intending to act and then controlling one's own actions. Volition consists of a series of decisions regarding whether to act, what action to perform and when to perform it. Neuroscientific accounts of voluntary action may inform debates about the nature of individual responsibility.

Introduction to the special issue on statistical and probabilistic methods for user modeling

Statistical and probabilistic models are concerned with the use of observed sample results to make statements about unknown, dependent parameters. In user modeling, these parameters represent aspects of a user’s behaviour, such as his or her goals, preferences, and forthcoming actions or locations. Recent technological advances, in particular increased computational power, together with anytime, anyplace access to computers, and the information explosion associatedwith the Internet, provide new opportunities for information dissemination and information gathering. On one hand, people have access to large repositories of information in digital form. On the other hand, information providers can find out more about their users’ requirements by logging people’s activities. This mixture of vast electronic content and increased knowledge about people’s actions provides an opportunity to harness statistical and probabilistic models to build user models that support the delivery of personalized content. This usage of statistical and probabilistic models has been manifested in UMUAI for the last ten years. Particularly noteworthy are the articles in the Special Issue on Machine Learning for User Modeling (1998); the survey articles by Zukerman and Albrecht and byWebb et al. in the 10-year anniversary issue, respectively on predictive statistical models for user modeling (Zukerman and Albrecht 2001), and on machine learning for user modeling (Webb et al. 2001); Burke’s survey on recommender systems (Burke 2002); and Pierrakos et al.’s survey on Web usage mining (Pierrakos et al. 2003). These articles identified several challenges that user modeling presents to statistical and probabilistic modeling techniques. We classify these challenges into three categories: (1) limitations of current user modeling approaches, (2) dynamic nature of user modeling data, and (3) efficiency considerations.

Applying the KnowCis methodology to a Greek municipality: a case study

The concept of the Knowledge City is a subfield of the Knowledge-Based Development which, during the last years, has attracted the interest of many researchers and practitioners. Various cities around the world have also undertaken considerable efforts and initiatives so as to be developed or to enhance their status as a Knowledge City. However, their approaches were rather ad-hoc and spontaneous and were not based on a pre-defined methodology. The research community has only recently begun to concentrate on the direction to substantiate the fundamental principles of Knowledge Cities and to define unified methodologies for their design, development and operation. Under this prism, the authors have recently proposed such a methodology, called KnowCis. The application of this methodology is currently in progress, on a Greek municipality. The municipality incorporates some special characteristics and features that render it a very advantageous case for this pilot application. This paper refers to the characteristics of the municipality and to the application of the KnowCis methodology, presents the progress of the effort and the preliminary results until now and provides useful insights on the forthcoming actions and plans of the city's administration. The outcomes, results and lessons-learnt of this pilot application will permit to fine-tune the KnowCis methodology.

Differential Involvement of Neurons in the Dorsal and Ventral Premotor Cortex During Processing of Visual Signals for Action Planning

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.

Projection and grammar: notes on the ‘action-projecting’ use of the distal demonstrative are in Japanese

Projection refers to the feature of human conduct that prefigures possible trajectories of how an action (or a sequence of actions) might develop in the next moment, and which thereby allows interactants to negotiate and accomplish coordinated action in the subsequent course of interaction. The present study explores the mechanism of projection with a focus on the relationship between projection and grammar. To that end, this study examines a particular turn-constructional practice involving the ‘action-projecting’ use of the distal demonstrative pronoun are (‘that one; that thing’) in Japanese. The point of departure for the study is the observation made by previous research that, due to some typological features of Japanese grammar, the projection of unfolding turn-shape and action-type is achieved relatively late in the course of a turn in Japanese. Through a detailed examination of relevant data from naturally-occurring Japanese conversations among peers as well as from TV talk shows, this study shows that Japanese speakers can nonetheless achieve early projection of forthcoming action through the use of the turn-constructional practice involving ‘action-projecting’ are and thereby compensate for delayed projectability. Issues arising from the analytic section of this study include the question of whether and how various projection techniques are grammaticized into grammatical constructions in different languages.

Reaching beyond spatial perception: Effects of intended future actions on visually guided prehension

Three experiments examined whether manipulating actors' intentions, regarding forthcoming actions, influences the time course and kinematics of visually guided, reach‐to‐grasp movements. Subjects performed two‐step action sequences where the initial movement always involved reaching for and grasping cubes located at a constant distance. Demands of the second movement were systematically manipulated. Although the spatial parameters (cube size and distance) remained constant across all conditions, the durations of the initial movements differed substantially depending on the actions subjects intended to perform once the objects were in hand. Less time was required to engage a small (1 cm3) cube when the intention was to transport it to a new location on the workspace vs. a large (4 cm3) cube when the goal was to merely lift it above its current resting position (Experiment 1). This difference in duration of the initial movement reflects more time spent in the deceleration phase of the reach when the task does not require transporting the cube to a new location on the workspace. Further, this context effect is not related to accuracy demands (Experiment 2), or complexity (Experiment 3) of the intended second movement. These findings demonstrate that actions are determined both by the perceived spatial demands of the immediate movement as well as the intended goal of the entire action sequence.

The role of prelimbic cortex in instrumental conditioning

Numerous studies have implicated human and primate prefrontal cortex in the ability to hold and manipulate goal or outcome-related information in working memory to guide the performance of forthcoming actions. Here we report that cell-body lesions of prelimbic cortex impair the ability of rats to select an action based on previously encoded action–outcome associations. Rats were food deprived and trained to press two levers, one delivering food pellets and the other a sucrose solution. All rats acquired the lever-press response although the initial acquisition in the prelimbic rats was significantly slower than in sham controls. Furthermore, whereas in sham-lesioned rats, post-training devaluation of one of the two outcomes using a specific satiety procedure produced a selective reduction in performance on the lever that in training delivered the prefed outcome, prelimbic rats failed to show a selective devaluation effect and appeared to reduce performance on both levers non-selectively. Importantly, this impairment only emerged in extinction; in subsequent experiments it was found that, when a specific action–outcome association was cued either by presentation of the outcome itself or by presenting a stimulus previously paired with the outcome, rats demonstrated an ability to select the associated action. These results suggest that action–outcome encoding may be intact in prelimbic rats and that the lesion impaired their ability to retain this learning in working memory in order to establish a course of action. Alternatively, the lesion may have altered the relative contribution of action–outcome and outcome–action associations to instrumental performance. On this account, prelimbic lesions affect action–outcome encoding but leave outcome–action associations intact providing the basis for outcome-mediated initiation of an action sufficient, perhaps, to support acquisition and performance in the lesioned rats.

The computational role of dopamine D1 receptors in working memory

The prefrontal cortex (PFC) is essential for working memory, which is the ability to transiently hold and manipulate information necessary for generating forthcoming action. PFC neurons actively encode working memory information via sustained firing patterns. Dopamine via D1 receptors potently modulates sustained activity of PFC neurons and performance in working memory tasks. In vitro patch-clamp data have revealed many different cellular actions of dopamine on PFC neurons and synapses. These effects were simulated using realistic networks of recurrently connected assemblies of PFC neurons. Simulated D1-mediated modulation led to a deepening and widening of the basins of attraction of high (working memory) activity states of the network, while at the same time background activity was depressed. As a result, self-sustained activity was more robust to distracting stimuli and noise. In this manner, D1 receptor stimulation might regulate the extent to which PFC network activity is focused on a particular goal state versus being open to new goals or information unrelated to the current goal.

The future of European geothermal energy: EGEC and the Ferrara Declaration

Geothermal energy is stored in the earth's interior in enormous amounts, but only a small part is currently exploited because of technical and economic constraints. Even so, present use in Europe covers electricity needs of 1 million people and provides heat to 1.1 million dwellings. The European outlook, as indicated in the Ferrara declaration of EGEC, the European Geothermal Energy Council, can be bright, provided public support is forthcoming and strong actions are taken.

Reinforcement-driven dimensionality reduction--a model for information processing in the basal ganglia.

Although anatomical studies of the basal ganglia show the existence of extensive convergence and lateral inhibitory connections, physiological studies failed to show correlated neural activity or lateral interaction in these nuclei. These seemingly contradictory results could be explained with a model in which the basal ganglia reduce the dimensionality of cortical information using optimal extraction methods. Simulations of this model predict a transient change in the efficacy of the feed-forward and lateral synapses following changes in reinforcement signal, causing an increase in correlated firing rates. This process ultimately restores the steady-state situation with diminished efficacy of lateral inhibition and no correlation of firing. Our experimental results confirm the model's predictions: rate correlations show a drastic decrease between the input stage (cortex) and output stage (pallidum). Moreover, preliminary analysis revealed that pallidal correlations show a transient increase following discrepancies between the animal's predictions and reality. We therefore propose that by using a reinforcement-driven dimensionality reduction process the basal ganglia achieve efficient extraction of cortical salient information that may then be used by the frontal cortex for execution and planning of forthcoming actions.

Dopamine-mediated stabilization of delay-period activity in a network model of prefrontal cortex.

The prefrontal cortex (PFC) is critically involved in working memory, which underlies memory-guided, goal-directed behavior. During working-memory tasks, PFC neurons exhibit sustained elevated activity, which may reflect the active holding of goal-related information or the preparation of forthcoming actions. Dopamine via the D1 receptor strongly modulates both this sustained (delay-period) activity and behavioral performance in working-memory tasks. However, the function of dopamine during delay-period activity and the underlying neural mechanisms are only poorly understood. Recently we proposed that dopamine might stabilize active neural representations in PFC circuits during tasks involving working memory and render them robust against interfering stimuli and noise. To further test this idea and to examine the dopamine-modulated ionic currents that could give rise to increased stability of neural representations, we developed a network model of the PFC consisting of multicompartment neurons equipped with Hodgkin-Huxley-like channel kinetics that could reproduce in vitro whole cell and in vivo recordings from PFC neurons. Dopaminergic effects on intrinsic ionic and synaptic conductances were implemented in the model based on in vitro data. Simulated dopamine strongly enhanced high, delay-type activity but not low, spontaneous activity in the model network. Furthermore the strength of an afferent stimulation needed to disrupt delay-type activity increased with the magnitude of the dopamine-induced shifts in network parameters, making the currently active representation much more stable. Stability could be increased by dopamine-induced enhancements of the persistent Na(+) and N-methyl-D-aspartate (NMDA) conductances. Stability also was enhanced by a reduction in AMPA conductances. The increase in GABA(A) conductances that occurs after stimulation of dopaminergic D1 receptors was necessary in this context to prevent uncontrolled, spontaneous switches into high-activity states (i.e., spontaneous activation of task-irrelevant representations). In conclusion, the dopamine-induced changes in the biophysical properties of intrinsic ionic and synaptic conductances conjointly acted to highly increase stability of activated representations in PFC networks and at the same time retain control over network behavior and thus preserve its ability to adequately respond to task-related stimuli. Predictions of the model can be tested in vivo by locally applying specific D1 receptor, NMDA, or GABA(A) antagonists while recording from PFC neurons in delayed reaction-type tasks with interfering stimuli.

Accounting for proposals

Conversationalists, before making a request or a proposal often do some preparatory work. In other words, speakers may start to project the final action before actually performing it. A more extensive procedure is (1) to project the action, (2) to expose some sort of trouble, and (3) to make the final request or proposal. This extensive preparatory work not only functions as an introduction to, and an account for the final action, but it also signals that the forthcoming action will be a ‘delicate’ action, i.e. a request or proposal which the speaker doesn't like to make and which the recipient may not like very much to accept: e.g., changing an appointment, asking for a favor, etc.

The Social Situation and Employment of Migrant Women in the European Community

Migrant women in the European Community (EC) tend to suffer from a cumulation of disadvantages. The highly developed EC legislation on the free movement of workers does not cover migrants originating in Third Countries (i.e. non Member States), and the relevant national legislation does not regard dependants as migrant workers in their own right. Migrant women from within and outside the EC experience numerous practical difficulties in obtaining access to training (particularly to mainstream courses) and to employment (particularly to better paid and more highly qualified jobs). It is vital that the European Community should continue its efforts to improve their situation under the forthcoming Action Programme on equal opportunities, as well as in its preparations for the single market after 1992.

The parameter remapping effect in human performance: Evidence from tongue twisters and finger fumblers

This article describes a series of experiments which show that motor performance suffers when responses in a repeated sequence have variable rather than fixed parameter mappings. In speech production, repeated recitation of the beginning of the alphabet is slowed dramatically if the same letters have different stress levels on successive cycles; the same effect holds for vowel-consonant relationships. In keyboard performance, repetitions of fingertapping sequences suffer if the number of consecutive taps by the same finger changes from cycle to cycle; we call these difficult sequences finger fumblers. Finally, similar effects are obtained with violin playing. The model we develop to account for these results says that parameter values mapped to the subprogram for a response item persist after the subprogram has been executed, and that extra processing is required if a new parameter value must be mapped to the subprogram the next time it is called for. This account is consistent with the view that motor programs for forthcoming actions are prepared by editing motor programs for actions that have just been completed. Because our results are similar to interference effects in traditional memory studies, we also suggest that similar mechanisms underlie storage and retrieval of motor responses and symbolic materials.

Disclaiming: A test of two competing views

Sociologists Hewitt and Stokes (1975) argue that disclaiming is a positive interactional tactic used to define forthcoming problematic actions as irrelevant to one's established identity. Several researchers interested in speech styles argue that disclaiming negatively impacts on one's identity by creating an image of powerlessness. The findings of an experiment reported here suggest that disclaimers have no effect, positive or negative, on others’ credibility attributions. This finding is inconsistent with past speech styles research. A second study supported a “hammer effect”; reinterpretation of these studies. It was only when subjects were presented with an unrealistic number of disclaimers that adverse effects for disclaiming were found.