The timing of bar-pressing behaviour

The time spent by a rat in a bar-pressing situation is made up of active time spent n pressing, eating time, and extra time spent in other activities. With a well trained rat, active time and extra time are small, and eating time mainly determines the rate of reward delivery. Active time is affected by a change of weight on the bar, the time between reward deliveries is affected by the amount of reward, and the extra time is affected by extinction conditions.

There is not a one-to-one correspondence between periods of activity at the knob and rewards.

The term “response” and some variables based on it are given empirical referents, which show that much research and theorizing on bar-pressing behaviour has been concerned with only a small selection of the rat's bar-pressing activities. Some reasons for this restriction are the use of the simple weighted bar, the lack of a rationale for bar-pressing research, and the practice of not watching the rat during an experiment.     

Early emotional instability,prosocial behaviour,and aggression: some methodological aspects

The internal consistency of Emotional Instability, Prosocial Behaviour, and Aggression scales was examined in elementary school children aged between 7 and 10 years. Multiple informants (self-report, teacher rating, mother rating, and peer nomination) were obtained on the above three dimensions. Relationships between the scales were first examined within the single informant frame of reference and then between informants. The concurrent validity was assessed using sociometric measures (popularity, rejection, social impact, and social preference) and the Achenbach and Edelbrock Child Behavior Checklist (teacher and parent form). The results confirm the internal validity of the three scales measuring emotional instability, prosocial behaviour, and aggression in child self-report, teacher rating, and mother rating. The use of self-report measures seems promising within the multiple informant strategy of research on child behaviour. Correlational results show satisfactory concurrent validity for the three scales, especially for teacher rating and peer nomination. The strict relation between emotional instability and aggression poses problems of discriminant validity which need to be further investi gated.     

The relationship between quantity,type, and timing of external childcare and child problem behaviour in Switzerland

This study aimed to investigate the relationship between external childcare and child problem behaviour at age 7 in a culturally diverse urban sample from Switzerland. We used data from the Zurich Project on the Social Development of Children and Youths (z-proso). Findings suggested that the quantity of group-based childcare (but not individual childcare) was related to aggression, ADHD, non-aggressive externalizing behaviour, and anxiety and depression at age 7. Analyses on timing of childcare suggested that the accumulation of childcare over the life course, and not so much childcare in the first years of life, was associated with child problem behaviour. In addition, childcare at age 5 to 7 had a unique relationship with problem behaviour over and above quantity of group-based childcare received in other age periods.     

Developmental differences in a coincident timing task under speed and time constraints

The present study examines the effects of speed constraints (target velocity) and time constraints (target duration) on performance on a coincident timing task by 5-, 7- and 9-year-old children and adults. The results showed that the young children significantly improved their performance (per cent of hits) and response accuracy CE, |CE| when given longer time to perform the task. The adults were just as successful for both durations. All subjects showed better performance (per cent of hits) with slower targets, however, for the children this effect was only noticeable with targets of long duration. Target duration also revealed development changes in response control and execution, with the younger children producing different response patterns for IRT, MT and IP measures. The developmental differences at this task are discussed in terms of the control mechanisms involved and the use of strategies in responding.     

Processing speed, executive function, and age differences in remembering and knowing.

A group of young (n = 52, M = 23.27 years) and old (n = 52, M = 68.62 years) adults studied two lists of semantically unrelated nouns. For one list a time of 2 s was allowed for encoding, and for the other, 5 s. A recognition test followed where participants classified their responses according to Gardiner's (1988) remember-know procedure. Age differences for remembering and knowing were minimal in the faster 2-s encoding condition. However, in the longer 5-s encoding condition, younger persons produced significantly more remember responses, and older adults a greater number of know responses. This dissociation suggests that in the longer encoding condition, younger adults utilized a greater level of elaborative rehearsal governed by executive processes, whereas older persons employed maintenance rehearsal involving short-term memory. Statistical control procedures, however, found that independent measures of processing speed accounted for age differences in remembering and knowing and that independent measures of executive control had little influence. The findings are discussed in the light of contrasting theoretical accounts of recollective experience in old age.     

Reciprocal relationships between three aspects of physical self-concept,vigorous physical activity,and lung function: A longitudinal study among late adolescents

ObjectivesThis prospective study, of older adolescents, investigated relationships between three aspects of physical self-concept, vigorous physical activity and lung function. In particular, physical competence, general appearance evaluations and body areas satisfaction were expected to predict subsequent physical activity, which, in turn, was expected to explain variation in lung function. In line with the reciprocal effect model, bi-directorial relationships were also tested. Gender was expected to moderate hypothesized relationships.DesignA longitudinal design, with three measurement points (baseline, 2-month follow-up, and 14-month follow-up) was employed.Method551 late adolescents (15–18 years old) provided self-reported data on physical activity, physical competence, body areas satisfaction, and appearance evaluation. Body weight, height, and a lung function index (forced expiratory volume in 1 s, FEV₁) were measured at baseline and at the 14-month follow-up.ResultsModerated mediation analyses indicated that physical competence at baseline predicted vigorous physical activity (2-month follow-up) among young men and women. Baseline body satisfaction and appearance evaluation were also related to vigorous physical activity (2-month follow-up) and this relationship was stronger for men. Vigorous physical activity predicted FEV₁ (14-month follow-up) and this relationship was stronger among women. The reciprocal pattern of relationships was not confirmed.ConclusionsFindings suggest that health promoting interventions should focus particularly on vigorous physical activity among young women, for example by boosting their physical competence.     

External memory: High speed,low speed,and no speed

This paper describes potential constraints on the selection of external memory devices (stimulus sources) and suggests options available to the would-be user of such systems for estimating research requirements and the functional parameters of the available external memory devices.     

Learned taste aversions in rats as a function of delay,speed, and duration of rotation

Rats fed a saccharin solution and then rotated on a turntable showed an aversion to the saccharin solution on later testing. In the first experiment, the rats learned to avoid saccharin with delays of as much as 9 hr between drinking the saccharin and the start of rotation. The second experiment showed that the critical determinant of aversiveness of rotation was number of rotations. The rats avoided saccharin as much after rotation at high speeds for short durations as after rotation at low speeds for long durations.     

Relationship between emotions and some aspects of respiratory activity: morphology of the chest, cyclic activity, and acid-base balance

The relationship between the style of affective-emotional management measured on the Gottschalk test and respiratory activity of 19 undergraduate students in psychology was examined. The biological measurements were tonic-static attitudes of the chest (morphology), amplitude and duration of the phases of the respiratory activity, and acid-base balance. Statistically significant correlations were observed between affectivity (hostility and anxiety) and some biological scores. A psychophysiological model integrating biological and psychological levels was discussed.     

Speed behaviour as a choice between observing and exceeding the speed limit

Despite speed behaviour being defined as a choice between several possible speeds, studies using theory of reasoned action or theory of planned behaviour to predict and understand speed behaviour have focused on exceeding and not on observing the speed limit. This study examines whether the evaluation of exceeding but also of observing the speed limit contributes to improving predictions of self-reported speed behaviour and determining intentions to produce each of these two behavioural options. For a specific driving situation (straight road with 90 km/h speed limit), 238 young male drivers reported the speed at which they would drive at and where asked to assess the theory of planned behaviour key constructs with respect to observing and exceeding the speed limit by at least 20 km/h. Results showed that the amount of explained variance of self-reported speed behaviour, as well as intentions to observe and to exceed the speed limit by at least 20 km/h, increased significantly when the evaluations of the two options were introduced in the same stepwise regression analysis. Theoretical and practical implications of the results are discussed.     

Behavioral speed contagion: automatic modulation of movement timing by observation of body movements

To coordinate our actions with those of others, it is crucial to not only choose an appropriate category of action but also to execute it at an appropriate timing. It is widely documented that people tend to unconsciously mimic others' behavior. The present study show that people also tend to modify their movement timing according to others' movements even when the observed and the to-be-executed movements are unrelated. Observers viewed either point-light biological motion, scrambled biological motion, or solid object motion. The stimulus sequence was presented at three different (half, normal, and double) rates. After a 300-2400-ms blank period, the observers performed a simple choice reaction-time task that was unrelated to the presented stimulus sequence. The observation of the biological motion produced a negative correlation between reaction time and stimulus speed, whereas no such trend was observed with the scrambled or solid object motion. Furthermore, speed-dependent modulation occurred only when the task was imposed within approximately 1s after the offset of the biological motion. These results suggest that behavioral tempo may be contagious; the speed of others' movements may automatically influence the timing of movement execution by the observer.     

Physical,neural, and mental timing

The conclusions drawn by Benjamin Libet from his work with colleagues on the timing of somatosensorial conscious experiences has met with a lot of praise and criticism. In this issue we find three examples of the latter. Here I attempt to place the divide between the two opponent camps in a broader perspective by analyzing the question of the relation between physical timing, neural timing, and experiential (mental) timing. The nervous system does a sophisticated job of recombining and recoding messages from the sensorial surfaces and if these processes are slighted in a theory, it might become necessary to postulate weird operations, including subjective back-referral. Neuroscientifically inspired theories are of necessity still based on guesses, extrapolations, and philosophically dubious manners of speech. They often assume some neural correlate of consciousness (NCC) as a part of the nervous system that transforms neural activity in reportable experiences. The majority of neuroscientists appear to assume that the NCC can compare and bind activity patterns only if they arrive simultaneously at the NCC. This leads to a search for synchrony or to theories in terms of the compensation of differences in neural delays (latencies). This is the main dimension of the Libet discussion. Examples from vision research, such as "temporal-binding-by-synchrony" and the "flash-lag" effect, are then used to illustrate these reasoning patterns in more detail. Alternatively one could assume symbolic representations of time and space (symbolic "tags") that are not coded in their own dimension (not time in time and space in space). Unless such tags are multiplexed with the quality message (tickle, color, or motion), one gets a binding problem for tags. One of the hidden aspects of the discussion between Libet and opponents appears to be the following. Is the NCC smarter than the rest of the nervous system, so that it can solve the problems of local sign (e.g., "where is the event"?) and timing (e.g., "when did it occur?" and "how long did it last?") on its own, or are these pieces of information coded symbolically early on in the system? A supersmart NCC appears to be the assumption of Libet's camp (which includes Descartes, but also mystics). The wish to distribute the smartness evenly across all stages of processing in the nervous system (smart recodings) appears to motivate the opponents. I argue that there are reasons to side with the latter group.     

Subitizing speed,subitizing range,counting speed,the Stroop effect,and aging: capacity differences and speed equivalence

Thirty younger and 29 older adults were tested on reaction times for set size of a display of 1 to 9 digits. On half of the trials, the nominal value of the digits was equal to the size of the set displayed; on the other half, the value differed by 1 from the set size (Stroop interference). We found evidence for age differences in subitizing span (2.83 vs. 2.07). Once individual differences in subitizing range were taken into account, no age differences were found in the rate of either subitizing or counting, and no individual differences were apparent in subitizing speed. There was no age difference in the susceptibility to the Stroop effect. The results suggest that, with advancing age, the size of the focus of attention may shrink, but speed of access to elements in the focus of attention may remain constant.     

Religious thought and behaviour as by-products of brain function

Religious concepts activate various functionally distinct mental systems, present also in non-religious contexts, and 'tweak' the usual inferences of these systems. They deal with detection and representation of animacy and agency, social exchange, moral intuitions, precaution against natural hazards and understanding of misfortune. Each of these activates distinct neural resources or families of networks. What makes notions of supernatural agency intuitively plausible? This article reviews evidence suggesting that it is the joint, coordinated activation of these diverse systems, a supposition that opens up the prospect of a cognitive neuroscience of religious beliefs.     

Before, during and after you disappear: aspects of timing and dynamic updating of the real-time action simulation of human motions

The detailed dynamics of action simulation was investigated using the occluder paradigm: a point light actor (PLA) was shown, then briefly occluded from view, during which period action simulation was generated. Following occlusion, the PLA reappeared, either a progression of the motion as it should be post-occlusion or temporally shifted earlier/later. Participants made judgements on whether the reappearing PLA was too early or too late to be a correct continuation (Experiments 1 and 3) or whether it was a veridical continuation or not (Experiment 2). Over three experiments we asked how action simulation is affected by motion information before, during and after occlusion. Reducing motion presented before occlusion retained the accuracy of action simulation judgements. Presenting 4 frames (67 ms) of PLA motion during the occluder duration dynamically updates or altogether regenerates the action simulation. Reducing the duration of the test motion after the occluder decreases judgement precision, which we interpret as a limitation in the process of postdictive motion judgments. Overall, this is further evidence that the action simulation process is remarkably adapted to making human motion predictions.