Beyond the comparator model: a multifactorial two-step account of agency

There is an increasing amount of empirical work investigating the sense of agency, i.e. the registration that we are the initiators of our own actions. Many studies try to relate the sense of agency to an internal feed-forward mechanism, called the "comparator model". In this paper, we draw a sharp distinction between a non-conceptual level of feeling of agency and a conceptual level of judgement of agency. By analyzing recent empirical studies, we show that the comparator model is not able to explain either. Rather, we argue for a two-step account: a multifactorial weighting process of different agency indicators accounts for the feeling of agency, which is, in a second step, further processed by conceptual modules to form an attribution judgement. This new framework is then applied to disruptions of agency in schizophrenia, for which the comparator model also fails. Two further extensions are discussed: We show that the comparator model can neither be extended to account for the sense of ownership (which also has to be differentiated into a feeling and a judgement of ownership) nor for the sense of agency for thoughts. Our framework, however, is able to provide a unified account for the sense of agency for both actions and thoughts.     

In defense of the one-factor doxastic account: A phenomenal account of delusions

According to the doxastic model, delusions are beliefs. In the metacognitive model, delusions are imaginings mistaken for beliefs. I argue that endorsement of false second-order beliefs could also create unpleasant dissonance, that mentally healthy people often endorse irrational or conflicting beliefs, and that the lack of delusion-motivated action can be explained by the influence of nonbelief factors on action. The two-factor doxastic model posits irrationality as necessary, and one metric of rationality many scholars employ is whether a response is easily understood by folk psychology. A precedent for folk-psychological acceptance of contextually bizarre beliefs as a result of personal experience can already be found in the lack of imaginative resistance encountered not in response to the impossibilities portrayed in speculative fiction, but in response to the characters’ ability to incorporate these occurrences into their mental frameworks, despite them often being at odds with these characters’ bedrock understanding of the world.     

Manual asymmetries in the preparation and control of goal-directed movements

The primary purpose of this experiment was to determine if left hand reaction time advantages in manual aiming result from a right hemisphere attentional advantage or an early right hemisphere role in movement preparation. Right-handed participants were required to either make rapid goal-directed movements to small targets or simply lift their hand upon target illumination. The amount of advance information about the target for a particular trial was manipulated by precuing a subset of potential targets prior to the reaction time interval. When participants were required to make aiming movements to targets in left space, the left hand enjoyed a reaction advantage that was not present for aiming in right space or simple finger lifts. This advantage was independent of the amount or type of advance information provided by the precue. This finding supports the movement planning hypothesis. With respect to movement execution, participants completed their aiming movements more quickly when aiming with their right hand, particularly in right space. This right hand advantage in right space was due to the time required to decelerate the movement and to make feedback-based adjustments late in the movement trajectory.     

Manual performance asymmetries and motor control processes: Subject-generated changes in response parameters

Performance asymmetries between the hands have recently been explained in terms of differences in the nature of motor control processes between the hands. If performance asymmetries between the hands on a serial tapping task are due to differences in motor control processes, the degree of asymmetry should be sensitive to changes in the manipulated response parameter, speed of tapping. The results strongly supported this prediction. The differences in control processes observed here seem to be explained by the feedback model proposed by Flowers. Alternate models to that of Flowers (1975) are, however, presented.     

Manual asymmetries in bimanual reaching: the influence of spatial compatibility and visuospatial attention

The goal of the present investigation was to explore the possible expression of hemispheric-specific processing during the planning and execution of a bimanual reaching task. Participants (N = 9) completed 80 bimanual reaching movements (requiring simultaneous, bilateral production of arm movements) to peripherally presented targets while selectively attending to either their left or right hand. Further, targets were presented in spatially compatible (ipsilateral to the aiming limb) and incompatible (contralateral to the aiming limb) response contexts. It was found that the left hand exhibited temporal superiority over the right hand in the response planning phase of bimanual reaching, indicating a left hand/right hemisphere advantage in the preparation of a bimanual response. During response execution, and consistent with the view that interhemispheric processing time (Barthelemy & Boulinguez, 2002) or biomechanical constraints (Carey, Hargreaves, & Goodale, 1996) generate temporal delays, longer movement times were observed in response to spatially incompatible target positions. However, no hemisphere-specific benefit was demonstrated for response execution. Based on these findings, we propose lateralized processing is present at the time of response planning (i.e., left hand/right hemisphere processing advantage); however, lateralized specialization appears to be annulled during dynamic execution of a bimanual reaching task.     

Manual asymmetries in the temporal and spatial control of aimed movements

Right-handed participants performed aimed, left- and right-hand movements toward a fixed target in speed and precision conditions. The purpose was to determine detailed hand differences in the temporal and spatial control during the course of a movement. The results showed that hand differences pertaining to spatial control of movement direction occurred throughout movement execution, and that these differences were stronger in the high speed and low precision conditions. Furthermore, the left hand took more time to execute a movement than the right hand, especially in conditions of low speed and high precision. Detailed time analysis revealed that slowing down of the left hand specifically happened prior to peak acceleration and beyond peak deceleration. These detailed temporal hand differences reoccurred as additional discontinuities in the acceleration profile. These results suggest that the left hand has more difficulty at movement start than the right hand, possibly in overcoming initial inertia. It is discussed whether time-based manual asymmetries located near the end of movement execution should be explained in terms of increased feedback use, or should be related to hand differences regarding the possible active dissipation of mechanical energy at movement completion.     

Manual asymmetries: feedback processing, output variability, and spatial complexity-resolving some inconsistencies

There is considerable evidence to document the case that the preferred hand is demonstrably superior for a number of manual tasks, although the mechanisms underlying this effect are less clear. Two perspectives have been dominant; one that emphasizes differential efficiency of feedback processing and one that suggests that asymmetries are a function of increased variability of output for the nonpreferred hand. This review considers the mediating effect of the complexity of the visual space in which aimed movements occur. Some inconsistencies may be resolved by noting the superiority of the right cerebral hemisphere for manipulation of spatial relationships. A multilevel, transactional perspective, which must then be adopted, may accommodate both feedback processing and motor output variability.     

In defense of an epistemic probability account of luck

Synthese - Many philosophers think that part of what makes an event lucky concerns how probable that event is. In this paper, I argue that an epistemic probability account of luck successfully...     

A defense of the subordinate-level expertise account for the N170 component

A recent paper in this journal reports two event-related potential (ERP) experiments interpreted as supporting the domain specificity of the visual mechanisms implicated in processing faces (Cognition 83 (2002) 1). The authors argue that because a large neurophysiological response to faces (N170) is less influenced by the task than the response to objects, and because the response for human faces extends to ape faces (for which we are not expert), we should reject the hypothesis that the face-sensitivity reflected by the N170 can be accounted for by the subordinate-level expertise model of object recognition (Nature Neuroscience 3 (2000) 764). In this commentary, we question this conclusion based on some of our own ERP work on expert object recognition as well as the work of others.     

Disability: a justice-based account

Philosophical Studies - Most people have a clear sense of what they mean by disability, and have little trouble identifying conditions they consider disabling. Yet providing a clear and consistent...     

Constructing a past in infancy: a neuro-developmental account

The ability to recall the past is fundamental yet until relatively recently, infants were assumed to lack the capacity. Contrary to this perspective, non-verbal tests indicate that developments in recall are well underway by late in the first year of life; by the end of the second year, long-term recall is reliable and robust. New research combining electrophysiological and behavioral measures is identifying the loci of age-related changes: they are attributed to more effective and efficient encoding, consolidation and storage processes associated with developments in the temporal-cortical network that subserves recall. The emerging framework, which applies to episodic and autobiographical memory, highlights the essential developmental continuities in memory from infancy onwards and sheds new light on the phenomenon of childhood amnesia.     

Classifying emotion: a developmental account

The aim of this paper is to propose a systematic classification of emotions which can also characterize their nature. The first challenge we address is the submission of clear criteria for a theory of emotions that determine which mental phenomena are emotions and which are not. We suggest that emotions as a subclass of mental states are determined by their functional roles. The second and main challenge is the presentation of a classification and theory of emotions that can account for all existing varieties. We argue that we must classify emotions according to four developmental stages: 1. pre-emotions as unfocussed expressive emotion states, 2. basic emotions, 3. primary cognitive emotions, and 4. secondary cognitive emotions. We suggest four types of basic emotions (fear, anger, joy and sadness) which are systematically differentiated into a diversity of more complex emotions during emotional development. The classification distinguishes between basic and non-basic emotions and our multi-factorial account considers cognitive, experiential, physiological and behavioral parameters as relevant for constituting an emotion. However, each emotion type is constituted by a typical pattern according to which some features may be more significant than others. Emotions differ strongly where these patterns of features are concerned, while their essential functional roles are the same. We argue that emotions form a unified ontological category that is coherent and can be well defined by their characteristic functional roles. Our account of emotions is supported by data from developmental psychology, neurobiology, evolutionary biology and sociology.     

Dissociation in Italian conjugations: a single-route account

Say and Clahsen (S and C) report an experiment involving assignment of past participle suffixes to nonce words in Italian. Their evidence suggests a dual-route model that assigns the theme vowel of the 1st conjugation, while storing it lexically in other conjugations. However, these nonce words were assigned suffixes by a computer algorithm that determined the past participle of the nonce items on the basis of phonological similarity to existing inflected forms. The outcome of the simulation mirrors that of the subjects closely, suggesting that the dissociations found by S and C are not adequate evidence for a dual-route model of Italian stem formation.     

Sequential effects in naming: a time-criterion account

S. J. Lupker, P. Brown, and L. Colombo (1997) reported that target naming latencies are strongly affected by the difficulty of the other stimuli in a trial block, an effect they attributed to readers' strategic use of a time criterion to guide responding. In the present research, the authors asked whether there are also trial-by-trial ("sequential") effects by examining naming latency as a function of the difficulty of the preceding stimulus. In Experiment 1, both nonwords and high-frequency regular words were named more rapidly following a word than a nonword. Experiments 2, 3, and 4 were parallel experiments involving a variety of stimulus types (e.g., high- and low-frequency inconsistent words, easy and hard nonwords). In all cases, similar sequential effects were observed (i.e., all stimulus types had shorter latencies following an easier-to-name than a harder-to-name stimulus). In terms of the time-criterion account, criterion placement appears to be affected by the relative difficulty of the preceding stimulus in a way that is independent of stimulus type.     

Holistic representation in juvenile defense: An evaluation of a multidisciplinary children's defense team

This study describes the results of an evaluation of a holistic defense model for juvenile clients. Longitudinal, retrospective analysis of de‐identified data from clients (N = 308) measured individual variable outcomes, relationships, and project performance. Bivariate and multivariate analyses examined the strength of association and interrelationships among client and defense team variables. Findings indicate that holistic defense was significantly associated with improved outcomes among juvenile clients, including increased mental health assessment resulting in treatment, increased employment and educational attainment, and decreased odds of recidivism. Favorable court or dispositional outcomes, including lower adjudication or early termination from custody, were also reported. Further practice‐level, controlled research is necessary to evaluate these models and offer comparison to other models for holistic defense.     

Task-effector asymmetries in a rhythmic continuation task

Variability in rhythmic movements has been interpreted as a signature of internal or peripheral noise processes. Grounded in an oscillator interpretation, this study hypothesized that period variability and drift arises from the asymmetry between target period and the limb's intrinsic dynamics. Participants synchronized to 7 target periods, swinging 1 of 3 pendulums in a continuation paradigm; 3 periods were longer, 3 shorter, and 1 identical to the preferred period. Results supported 5 predictions: Drift toward the preferred period was observed that scaled with the asymmetry. Variability was lowest for symmetry conditions and increased with the asymmetry. Variability decreased concomitant with the approach toward the preferred period. Periods exponentially approached the preferred period with positive autocorrelations up to 10 cycles.