Performance and learning of generalized motor programs: relative (GMP) and absolute (parameter) errors

The effects of practice (Experiment 1) and parameter variability (Experiment 2) on the learning of generalized motor programs (GMPs) and movement parameterization were investigated. In each experiment, 2 tasks with different relative force-time structures were tested. Participants (N = 32, Experiment 1; N = 40, Experiment 2) attempted to exert a pattern of force that resembled in force and time a waveform that was displayed on a computer monitor. In both experiments, the analysis suggested that the GMP, although refined over practice, was relatively stable (i.e., resistant to decay and interference), even early in practice (after 20 trials). In addition, the results indicated that constant and variable parameter practice did not differentially affect GMP learning but did degrade the learning of the parameter that was not varied. The data provided additional evidence for the dissociation of the GMP and the parameterization processes proposed in GMP theory. Contrary to schema theory, the present data suggest an interdependence between the force and the time parameters: The manipulation of 1 of the parameters has a negative effect on the learning of the other parameter.     

Sex differences in mathematical reasoning ability at age 13: their status 20 years later

Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose assessments at age 12 to 14 revealed robust gender differences in mathematical reasoning ability. Both sexes became exceptional achievers and perceived themselves as such; they reported uniformly high levels of degree attainment and satisfaction with both their career direction and their overall success. The earlier sex differences in mathematical reasoning ability did predict differential educational and occupational outcomes. The observed differences also appeared to be a function of sex differences in preferences for (a) inorganic versus organic disciplines and (b) a career-focused versus more-balanced life. Because profile differences in abilities and preferences are longitudinally stable, males probably will remain more represented in some disciplines, whereas females are likely to remain more represented in others. These data have policy implications for higher education and the world of work.     

An ethics perspective on transcranial magnetic stimulation (TMS) and human neuromodulation

This paper concerns the ethics of human neuromodulation using transcranial magnetic stimulation (TMS). We examine the challenges of modulating the brain with TMS through the research ethics lens and in clinical medicine for treating frank pathology, primarily in psychiatric diseases. We also consider contemporary issues raised in the neuroethics literature about managing unexpected findings, and relate these to TMS and to other frontier neurotechnology that is becoming openly available in the public domain. We argue that safety and informed consent are of paramount importance for TMS, but that personal values and sociocultural factors must also be considered when examining the promise of this technology and applications that ought to be highlighted for extra precautions.     

Cholinergic modulation of trace conditioning trained in serial compound: A developmental analysis

In four experiments the effects of serial compound conditioning on responding to a trace-conditioned CS were evaluated using a fear conditioning paradigm. The subjects were 18- and 25-day-old Sprague-Dawley rats, previously shown to exhibit little or no trace fear conditioning. Here, animals as young as 18 days of age were shown to be capable of trace conditioning between a visual CS1 and a shock US, provided the trace interval was filled with a non-target CS2 during serial conditioning trials (CS1-->CS2-->US). To explore cholinergic mechanisms involved in trace and serial conditioning, additional experiments assessed conditioned responding following pre-training administration of the muscarinic receptor antagonist scopolamine. Scopolamine produced a dose-dependent reduction in responding to the trace CS1, regardless of whether subjects were trained with standard trace (CS1-->trace interval-->US) or serial (CS1-->CS2-->US) trials. Responding to CS2 was unaffected by scopolamine. These data suggest that central cholinergic systems are functional in the young animals, but are not normally sufficiently activated by standard trace conditioning procedures. The results suggest that serial compound conditioning can promote trace conditioning in young rats, as it does in adults, perhaps by enhancing cholinergic activity during training. Implications for the late ontogenetic emergence of trace conditioning as it relates to maturation of neural pathways and their role in the potentiating effects of a gap filler are discussed.     

Young children make scale errors when playing with dolls

Prior research (DeLoache, Uttal & Rosengren, 2004) has documented that 18- to 30-month-olds occasionally make scale errors: they attempt to fit their bodies into or onto miniature objects (e.g. a chair) that are far too small for them. The current study explores whether scale errors are limited to actions that directly involve the child's body. We investigated whether children would also make scale errors with a doll and objects that were much too small for the doll (e.g. a chair, a bed). Many participants did try to fit the doll into or onto the miniature objects. Thus, the previously documented phenomenon of scale errors extends to situations in which the relevant size difference is between two objects. This finding supports the view that scale errors occur when visual information about object size fails to influence the decision to act on an object. The results are discussed in terms of the use of visual information for the planning and control of actions.     

Intention in motor learning through observation

The purpose of this experiment was to assess whether learning an action through observation is enhanced by the intention to reproduce the observed behaviour. Two groups of participants observed a model practise a timing task and performed a 24-hour delayed retention test. Participants in the first group of observers were explicitly instructed that they would be required to execute the timing task that they had observed as accurately as possible during the delayed retention test. Observers in the second group were instructed that they would be required to describe as accurately as possible the behaviour that they had observed. A control group of participants, who did not observe the model, was also administered the delayed retention test. The results of the retention test indicated that absolute timing (parameterization) was learned by the observers to the same extent with or without intention to reproduce the task. Indeed, on the retention test absolute timing for the two groups of observers was as effective as that for the models. However, observing with an intention to reproduce the task was beneficial for learning the movement's relative timing structure. Results are discussed with respect to a potential mechanism by which intention enhances observation.     

Writing about patients: I. Ways of protecting confidentiality and analysts' conflicts over choice of method

Thirty American psychoanalysts who have published articles using clinical material from their patients were interviewed about their method for ensuring confidentiality. Almost twice as many analysts chose to disguise material as regularly requested permission for the use of patients' material. The other analysts in the sample varied their approach, depending on circumstances, between using disguise alone and using disguise but also requesting consent. Methods of disguise, the timing of request for permission in relation to the phase of analysis, and changes in analysts' ideas about the benefits and detrimental effects of these choices are discussed and illustrated. Each decision is reconsidered in light of its potential effect on patients and their analysis. The dilemma posed by the importance of writing about patients for the health and growth of psychoanalysis as a field and the potential negative consequences for patients and their analyses is considered.     

Patients reading about themselves: a stimulus to psychoanalytic work

Patients' reading of their psychoanalysts' papers about them as a vehicle for psychoanalytic work is a relatively new phenomenon in the field. Over the past five years, reports of analysts' employment of their writing in this fashion have begun to appear in the analytic literature. This paper presents clinical illustrations of this specific use of analysts' writing. These illustrations were drawn from interviews with analysts who published clinical articles in Psychoanalytic Dialogues between 1995 and 2003. The author considers some of the clinical and scientific implications of this use of papers written for publication.