The Piéron function in the threshold region

The Piéron function (Piéron, 1914, 1920, 1952) describes the decay of reaction time (RT) when the intensity of the stimulus is increased. It is generally demonstrated within a suprathreshold range of intensities. However, in some studies, for the lowest range of intensities, the exponent of the function is clearly greater than that for the upper ranges of intensities. Such an increase in the exponent for the lowest intensities is assumed to result from a combined effect of stimulus intensity and of stimulis uncertainty in detection. Our first experiment used luminance levels that covered all the scotopic range and a spatial two-alternative forced-choice task in which both accuracy and RT were measured. It demonstrated a drastic increase in the exponent in the Piéron function when the intensities reached the threshold region. Since the estimates of the threshold region may have been biased by the use of a much larger range of luminances, a second experiment was conducted using luminances that covered only the threshold region. This experiment confirmed the previous estimates for the threshold region.     

« Docteur,pourrais-je avoir une copie du certificat ? » Étude pluricentrique concernant l’application des décrets du 31 mars 2021 et du 23 novembre 2021

On 31 March 2021, a decree was published in the Official Journal concerning the procedures for the delivery of medical certificates to victims of violence. These victims can now obtain a copy of the certificate drafted by the doctor required by the judicial authorities, particularly as regards medical examiners.PurposeThe aim of our study was to assess the impact of the March 31, 2021 decree on victims’ requests to the medical examiner for a copy of the medical certificate.MethodsThis prospective study was conducted among three forensic services receiving victims in consultation, using a paper questionnaire linked to Medlé data, over a three-month period.ResultsOf the 1,492 consultations conducted during the study period, a copy of the certificate was only given to the victim in 13.1 % of the consultations. It was requested spontaneously by the victim in 15.2 % of cases, most often to exercise his right (46.4 %). These were primarily consultations following an accident, psychological abuse, and assault. This copy was requested spontaneously by less than 3 % of victims of domestic violence. There was some disparity between the three centres regarding the minor victim.ConclusionThis study is a small sample over a short period. The information of the victims, especially of domestic violence, on access to the copy of the medical-legal certificate seems still insufficient, and the principle of surrender, when it can help the victim in his efforts, can also be a source of confusion.     

Comme réponse à la précarité du lien mère–bébé, les « Petits Pas » : un réseau en périnatalité…

The “Baby Steps” network includes a multi-disciplinary team and aims to accompany parents-to-be and young parents as they meet their newborns. The exchange and development relationships that professionals develop among themselves help to support the notion of parenthood and circumscribe any potential risk. The professionals in the network hail from a variety of backgrounds but they are all involved in perinatal care and by grouping their skills can adapt and optimise the assistance and care they offer to parents. The “Parent Island” reception area and the mother-baby therapy group with a separate father oriented structure are the truly original aspects of the network. Prevention is vital, as is providing therapeutic care for disturbances related to early parent-child relationships. With a strong “group psychology focus” the network creates a sufficiently solid structure to receive any unconscious negative projections from momentarily or deeply distressed parents.     

Usage légal du titre de « psychothérapeute » : stratégies des acteurs concernés

The law proposal of the deputy Bernard Accoyer adopted by the National Assembly the 13th of March 1999, after many debates, finally led to a law article on use of psychotherapist title. Several consultation meetings with professional organizations in the Health Ministry took place about its future application decree, nevertheless without a consensus because of the contradictory interests for people practising psychotherapy. Are concerned two regulated professions — psychologists and physicians — and two types of non-regulated activities, psychoanalysts and “psychotherapists” which are not physicians and not psychologists. These last ones defend in France, as it's the fact in some other european countries, the creation of the independant profession of “psychotherapist”; a minority part of psychoanalysts societies support them, leant upon the principle of practice liberty. The opinion differences are focused on the training criteria in psychopathology required by the law, some organizations disputing that this training be a university monopoly. Another ambiguity deals with the law gives a miss about the actual psychotherapy training, the Senate having chosen for the minimum requirement of a psychopathology training. The subject of this paper is to come back on the strategies and the identity stakes of actors mobilized during the different drafts of this law proposal and to prepare the ground about the ideological positions underlying by these strategies.     

« Mon enfant est-il surdoué ? » Que demande-t-on ?

Is it possible to identify the specific characteristics as well as the scope of the phenomenon of demands concerning giftedness? The author presents and comments a set of data reflecting the activity of a Parisian consultation center over two separate years: 2004 (12% of the demands concern giftedness) and 2006 (11% of the demands concern giftedness). The psychometrical investigations are based on the Wechsler Scales (WISC-III; WISC-IV). The percentage of demands related to giftedness is quite high as compared to other motives. It mainly concerns children who do not show what are called “very superior” intellectual abilities. The development of certain social stereotypes could be an explanation.     

Quelle place pour les médiations thérapeutiques dans la « psychothérapie par l'institution » ?

Therapeutic mediations are an essential part of the communautary treatment offered by our Clinic (Clinique Dupre de Sceaux). They contribute to the adaptation of our therapeutic program to the psychopathological characteristics of our adolescents and young adults patients. We see this therapeutic mediations as a tool to allow a bounding between the treating team and patients whose central psychopathological feature is the fear of bounding and relationship with significative others seen as potential threat of dependency and/or seduction. Through therapeutic mediations, the treating staff is able to deal with repetitive symptomatic situations, using the empathic capacity of each member of the team included in the “psychic enlarged space” of the patient. Therapeutic mediations are the contributing to regulate the bounding process in this type of patient. Through a clinical presentation this paper will present the use of therapeutic mediations in our Clinic. We will then discuss more widely the concept of “psychotherapy through the institution” we use in this type of therapeutic setting.     

« L’étrange victoire »

This paper reevaluates firmly, humorously and at times indignantly the major events of the Covid 19 epidemics. They remind the author of certain episodes of the « phony war » and of the blitzkrieg from which Marc Bloch had drawn powerful lessons in a book which is still famous today. Our dear nation‘s failings thus prove timeless.     

The role of response mechanisms in determining reaction time performance: Piéron’s law revisited

A response mechanism takes evaluations of the importance of potential actions and selects the most suitable. Response mechanism function is a nontrivial problem that has not received the attention it deserves within cognitive psychology. In this article, we make a case for the importance of considering response mechanism function as a constraint on cognitive processes and emphasized links with the wider problem of behavioral action selection. First, we show that, contrary to previous suggestions, a well-known model of the Stroop task (Cohen, Dunbar, & McClelland, 1990) relies on the response mechanism for a key feature of its results—the interference—facilitation asymmetry. Second, we examine a variety of response mechanisms (including that in the model of Cohen et al., 1990) and show that they all follow a law analogous to Piéron’s law in relating their input to reaction time. In particular, this is true of a decision mechanism not designed to explain RT data but based on a proposed solution to the general problem of action selection and grounded in the neurobiology of the vertebrate basal ganglia. Finally, we show that the dynamics of simple artificial neurons also support a Piéron-like law.     

Les capacités d'inhibition : une fonction « frontale » ?

It has been strongly suggested that one important function related to frontal lobes is inhibition. However, a review of the literature on classical tests of inhibition (Stroop test, WCST, and AB-AC learning) suggests that this hypothesis is not well established. We further examined this hypothesis using short-term and long-term directed forgetting tasks (Reed, 1970, Zacks et al., 1996), the Stroop test and the Hayling test (Burgess and Shallice, 1996) in 13 patients with focal frontal lesions. The results revealed short-term and long-term memory deficits and a slowing down, but no inhibition deficit compared with control subjects. These results question the relevance of the hypothesis of the frontal lobe as the unique substrate of inhibitory mechanisms. More generally, they address the issue of executive functions: are these sustained by the frontal cortex or by a cortical and subcortical diffuse neural network?     

La fin de l'adolescence pour un état adulte : mythe ou réalité ?

Research in philosophy, sociology, psychiatry, psychology and psychoanalysis converge on the one hand to describe modernism as an approach to ignoring subjectivity, as a consequence of the power of the economy, and on the other hand the identification of the word as an instrument of the advent of subjective autonomy, the only real “maturity” which exists. By its words, the individual becomes autonomous from this economic matter as it does from its fantasies. There are many, of all ages, who never reach this position. Consequently, does the postulate of adolescence being limited to an age bracket have any sense? And doesn't all that has been said referring to this concept apply in fact to all social suffering?     

Intensity and number of alternatives in hue identification: Piéron’s law and choice reaction time

Two experiments investigated the effects of intensity and the number of response alternatives in hue identification. Three questions were addressed. First, what is the relationship between these effects? If intensity and number of alternatives affect different processes in series, these factors would have additive effects on reaction time (RT). Other models predict a multiplicative interaction. These models assume that when a stimulus is presented, evidence accrues over time for each response alternative, and that when the evidence for a particular alternative exceeds its criterion, the response is made. A natural auxiliary assumption is that intensity affects the rate of evidence accrual, while the number of alternatives affects the criterion. The second question addressed is, how does choice RT change as a function of intensity? Piéron used a power function to describe the effect of intensity on simple RT. This paper considers three candidates for intensity’s effect on choice RT: the power, logistic, and Michaelis functions. Each candidate function was tested in an additive model and a multiplicative model. The best account was given by the power function in an additive model. The last question is, does each process produce an output that can be classified as correct or incorrect? Schweickert (1985) proposed that factors that selectively influenced such processes would have additive effects on log percent correct. Instead, an interaction was found. Perhaps the assumption that the process affected by intensity produces a single output is wrong.