A NEURAL SYSTEM FOR ERROR DETECTION AND COMPENSATION

Abstract— Humans can monitor actions and compensate for errors. Analysis of the human event-related brain potentials (ERPs) accompanying errors provides evidence for a neural process whose activity is specifically associated with monitoring and compensating for erroneous behavior. This error-related activity is enhanced when subjects strive for accurate performance but is diminished when response speed is emphasized at the expense of accuracy. The activity is also related to attempts to compensate for the erroneous behavior.     

Analyses of multinomial mixture distributions: new tests for stochastic models of cognition and action

Mixture distributions are formed from a weighted linear combination of 2 or more underlying basis distributions [g(x) = sigma j alpha j fj(x); sigma alpha j = 1]. They arise frequently in stochastic models of perception, cognition, and action in which a finite number of discrete internal states are entered probabilistically over a series of trials. This article reviews various distributional properties that have been examined to test for the presence of mixture distributions. A new multinomial maximum likelihood mixture (MMLM) analysis is discussed for estimating the mixing probabilities alpha j and the basis distributions fj(x) of a hypothesized mixture distribution. The analysis also generates a maximum likelihood goodness-of-fit statistic for testing various mixture hypotheses. Stochastic computer simulations characterize the statistical power of such tests under representative conditions. Two empirical studies of mental processes hypothesized to involve mixture distributions are summarized to illustrate applications of the MMLM analysis.     

A clinical interview for parents of high-risk infants: Concept and applications

The birth and hospitalization of a preterm infant are stressful and emotionally demanding experiences for parents. The Clinical Interview for Parents of High-Risk Infants (CLIP) is a semistruc tured clinical interview that may be used as a one-time assessment or as a cornerstone for ongoing psychosocial work with parents. The interview assesses early parental adaptation and alerts the clinician to areas of concern as identified by the parents. The interview enables parents to consolidate emotionally their experiences relative to the infant's high-risk status. The CLIP has utility both for planning psychosocial care in the intensive care nursery, and for discharge preparation. The rationale underlying the design of the CLIP is presented, the interview is described, and clinical applications are discussed.     

On Agents That Have the Ability to Choose

We demonstrate ways to incorporate nondeterminism in a system designed to formalize the reasoning of agents concerning their abilities and the results of the actions that they may perform. We distinguish between two kinds of nondeterministic choice operators: one that expresses an internal choice, in which the agent decides what action to take, and one that expresses an external choice, which cannot be influenced by the agent. The presence of abilities in our system is the reason why the usual approaches towards nondeterminism cannot be used here. The semantics that we define for nondeterministic actions is based on the idea that composite actions are unravelled in the strings of atomic actions and tests that constitute them. The main notions used in defining this semantics are finite computation sequences and finite computation runs of actions. The results that we obtain meet our intuitions regarding events and abilities in the presence of nondeterminism.     

Evaluating backward chaining methods on vocational tasks by adults with developmental disabilities

Backward chains are widely used to teach complex skills to individuals with developmental disabilities. Implementation of chaining procedures may vary regarding untaught steps and there is little to guide practitioners in the selection of chaining procedures. Moreover, there is a dearth of research evaluating effectiveness and efficiency of procedural variations of behavior chains. The purpose of this study was to extend previous research by evaluating the effectiveness, efficiency, and preference for four procedural variations (i.e., teacher‐completion, participant‐completion, no‐completion, and a control condition) of backward chains across vocational tasks with adults with developmental disabilities. Although procedural variations effectively established vocational skills, the participant‐completion procedure (in which the instructor implemented a least‐to‐most prompt hierarchy during all untrained steps in the chain) was the most efficacious backward chaining procedural variation and efficient in terms of sessions to mastery. The no‐completion procedure (in which the instructor completed all untrained steps in the chain out of view of the participant) was least efficient across trials, sessions, errors, and total duration to mastery. One participant preferred the no‐completion condition while the other two participants showed an initial preference for the teacher‐completion condition that changed to preference for the no‐completion condition. Vocational skills maintained 1‐ and 4‐weeks postmastery. Stakeholders rated goals, procedures, and outcomes as socially valid.     

‘Something in the way you move’: Infants are sensitive to emotions conveyed in action kinematics

Body movements, as well as faces, communicate emotions. Research in adults has shown that the perception of action kinematics has a crucial role in understanding others’ emotional experiences. Still, little is known about infants’ sensitivity to body emotional expressions, since most of the research in infancy focused on faces. While there is some first evidence that infants can recognize emotions conveyed in whole‐body postures, it is still an open question whether they can extract emotional information from action kinematics. We measured electromyographic (EMG) activity over the muscles involved in happy (zygomaticus major, ZM), angry (corrugator supercilii, CS) and fearful (frontalis, F) facial expressions, while 11‐month‐old infants observed the same action performed with either happy or angry kinematics. Results demonstrate that infants responded to angry and happy kinematics with matching facial reactions. In particular, ZM activity increased while CS activity decreased in response to happy kinematics and vice versa for angry kinematics. Our results show for the first time that infants can rely on kinematic information to pick up on the emotional content of an action. Thus, from very early in life, action kinematics represent a fundamental and powerful source of information in revealing others’ emotional state.     

Motion tracking of parents’ infant‐ versus adult‐directed actions reveals general and action‐specific modulations

Parents tend to modulate their movements when demonstrating actions to their infants. Thus far, these modulations have primarily been quantified by human raters and for entire interactions, thereby possibly overlooking the intricacy of such demonstrations. Using optical motion tracking, the precise modulations of parents’ infant‐directed actions were quantified and compared to adult‐directed actions and between action types. Parents demonstrated four novel objects to their 14‐month‐old infants and adult confederates. Each object required a specific action to produce a unique effect (e.g. rattling). Parents were asked to demonstrate an object at least once before passing it to their demonstration partner, and they were subsequently free to exchange the object as often as desired. Infants’ success at producing the objects’ action‐effects was coded during the demonstration session and their memory of the action‐effects was tested after a several‐minute delay. Indicating general modulations across actions, parents repeated demonstrations more often, performed the actions in closer proximity and demonstrated action‐effects for longer when interacting with their infant compared to the adults. Meanwhile, modulations of movement size and velocity were specific to certain action‐effect pairs. Furthermore, a ‘just right’ modulation of proximity was detected, since infants’ learning, memory, and parents’ prior evaluations of their infants’ motor abilities, were related to demonstrations that were performed neither too far from nor too close to the infants. Together, these findings indicate that infant‐directed action modulations are not solely overall exaggerations but are dependent upon the characteristics of the to‐be learned actions, their effects, and the infant learners.     

Social-cognitive functioning and schizotypal characteristics

The authors examined the relationship between social cognition and a feature of schizotypal personality referred to as magical ideation, defined broadly as the presence and intensity of illogical beliefs about causality and the nature of reality. The measures of social cognition used in this study were the Character Intention Task (CIT) and the adult version of the Reading the Mind in the Eyes Test. Regression analyses indicated that understanding of character intentions, as measured by CIT scores, and ability to identify emotions on the Eyes test were related to non-realistic beliefs. Principal components analysis of the Magical Ideation Scale generated 3 factors: Occult Beliefs, Non-Realism, and New Age Ideas. Results indicated that impaired understanding of character intentions and ability to identify emotions on the Eyes test were related to non-realistic beliefs. Understanding the cognitive impairments associated with schizotypal characteristics can facilitate development of more targeted therapeutic interventions.