Visual perspective taking for avatars in a Simon task

In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus–response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus–response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus–response mappings, causing a compatibility effect from the avatar’s point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants’ sense of agency over the avatar, a spatial compatibility effect from the avatar’s perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.     

Anomalous cerebral language organization: acquired crossed aphasia in a dextral child

Following a dramatic change of its reported incidence, it was only recently recognized that acquired crossed aphasia in dextral children represents a highly exceptional phenomenon. We describe in a three epoch time-frame model the aphasic and neurocognitive manifestations of an additional case and focus briefly on its anatomoclinical configurations. In our patient, a right parietal cortico-subcortical hemorrhagic lesion caused an initially severe aphasia. After remission of the global aphasic symptoms in the acute phase, an adynamic output disorder with relatively severe auditory-verbal comprehension disturbances developed. In addition to the adynamia of self-generated speech, formal language investigations performed 3 weeks postonset, revealed agrammatism, hypertonic dysarthria, and dysprosodia. A substantial improvement of the aphasic disorder was objectified 83 days postonset. Neuropsychological investigations disclosed both dominant and nondominant hemisphere dysfunctions. Reassessment of neurocognitive functions after a 10-year period evidenced discrete residual anomia, confined to visual confrontational naming and a discrete visuo-perceptual syndrome. Given the posterior localization of the lesion, the syndrome shift from global to predominantly adynamic aphasia represents a finding beyond the plausible anatomoclinical expectations holding in general for the uncrossed, classic types of childhood and adult aphasia. As the first representative of crossed aphasia in dextral children with an anomalous lesion-aphasia profile, our case provides evidence to enrich the discussion on lateralization and intrahemispherical organization of language functions in both childhood and adult aphasia.     

Social influences on parental and nonparental responses toward pups in virgin female prairie voles (Microtus ochrogaster)

Pair-bonded prairie voles (Microtus ochrogaster) are biparental after the birth of pups. However, whereas most adult virgin males are parental, most virgin females are not. In 6 experiments, influences on the parental behavior of virgin female prairie voles were examined. It was found that (a) young virgin females were more maternal than older females, (b) the postweaning sex ratio of cage-mates did not affect females' responses to pups, (c) females raised to adulthood with their parents and younger siblings present were highly parental, (d) 48-hr exposure to pups beginning at weaning increased some aspects of later maternal responding, (e) rearing to adulthood with the parents even in the absence of younger siblings also increased females' maternal responding, and (f) the increase was seen only if both parents were present. Continued parental presence promotes alloparental behavior, possibly important if daughters do not disperse from the natal nest.     

Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.     

The puzzle of language evolution

Linguistics must again concentrate on the evolutionary nature of language, so that language models are more realistic with respect to human natural languages and have a greater explanatory force. Multi-agent systems are proposed as a possible route to develop such evolutionary models and an example is given of a concrete experiment in the origins and evolution of word-meaning based on a multi-agent approach.     

Betrayal And Paranoia: The Psychotherapist's Function as an Intermediary

We present an approach to the problem of structuring a therapeutic alliance with patients presenting paranoid symptoms, using both psychoanalytical and cognitive techniques. Initially, we focused on one of the main aspects of the paranoid worldview: the fear of being betrayed and the tendency to betray. This is a defense maneuver, through which patients deny their passivity, and the impotence in the relationship with their own internal needs and with the significant people in the external world, including the therapist. In our experience to build up a working relationship, both a psychoanalytical interpretation of unconscious conflicts and the cognitive analysis of dysfunctional beliefs are needed. Often, in more serious cases, the role of nonqualified object must be accepted at the beginning, due to the patient's need to be in control of the situation. Only then can a therapeutic phase begin, in most cases, through an integrated approach that includes pharmacological, psychodynamic, and cognitive modalities.     

The gap effect in newborns

In four experiments we investigated the gap effect in infants within the first 3 days of life. Reaction times (RTs) to make a saccade to a peripheral target were measured on gap trials, in which the central fixation stimulus went off 500 ms before target presentation, and on overlap trials, in which the central fixation stimulus remained on. In every experiment the fixation stimulus was a flashing light. The target stimulus was a schematic face in Experiment 1, a flashing light shown at 20° eccentricity in Experiment 2, a flashing light shown at 30° eccentricity in Experiment 3, and an upside-down schematic face in Experiment 4. In Experiments 1–3 a gap effect was found. That is, RT was faster on gap than on overlap trials. In contrast, the gap effect was absent in Experiment 4. These findings are consistent with the view that the superior colliculus plays a major role in producing the gap effect at birth.