Simple and conditional visual discrimination with wheel running as reinforcement in rats.

Three experiments explored whether access to wheel running is sufficient as reinforcement to establish and maintain simple and conditional visual discriminations in nondeprived rats. In Experiment 1, 2 rats learned to press a lit key to produce access to running; responding was virtually absent when the key was dark, but latencies to respond were longer than for customary food and water reinforcers. Increases in the intertrial interval did not improve the discrimination performance. In Experiment 2, 3 rats acquired a go-left/go-right discrimination with a trial-initiating response and reached an accuracy that exceeded 80%; when two keys showed a steady light, pressing the left key produced access to running whereas pressing the right key produced access to running when both keys showed blinking light. Latencies to respond to the lights shortened when the trial-initiation response was introduced and became much shorter than in Experiment 1. In Experiment 3, 1 rat acquired a conditional discrimination task (matching to sample) with steady versus blinking lights at an accuracy exceeding 80%. A trial-initiation response allowed self-paced trials as in Experiment 2. When the rat was exposed to the task for 19 successive 24-hr periods with access to food and water, the discrimination performance settled in a typical circadian pattern and peak accuracy exceeded 90%. When the trial-initiation response was under extinction, without access to running, the circadian activity pattern determined the time of spontaneous recovery. The experiments demonstrate that wheel-running reinforcement can be used to establish and maintain simple and conditional visual discriminations in nondeprived rats.     

Techniques for establishing schedules with wheel running as reinforcement in rats.

In three experiments, access to wheel running was contingent on lever pressing. In each experiment, the duration of access to running was reduced gradually to 4, 5, or 6 s, and the schedule parameters were expanded gradually. The sessions lasted 2 hr. In Experiment 1, a fixed-ratio 20 schedule controlled a typical break-and-run pattern of lever pressing that was maintained throughout the session for 3 rats. In Experiment 2, a fixed-interval schedule of 6 min maintained lever pressing throughout the session for 3 rats, and for 1 rat, the rate of lever pressing was positively accelerated between reinforcements. In Experiment 3, a variable-ratio schedule of 20 or 35 was in effect and maintained lever pressing at a very stable pace throughout the session for 2 of 3 rats; for 1 rat, lever pressing was maintained at an irregular rate. When the session duration was extended to successive 24-hr periods, with food and water accessible in Experiment 3, lever pressing settled into a periodic pattern occurring at a high rate at approximately the same time each day. In each experiment, the rats that developed the highest local rates of running during wheel access also maintained the most stable and highest rates of lever pressing.     

Relationship between driving styles and biological behavior of drivers in negative emotional state

ObjectiveThis paper explores the links between driving style and the biological behavior of people while driving with dangerous negative emotions (such as anger, anxiety, and fear).BackgroundIt is highly important to study the behavior of humans from varying aspects to discover the factors affecting it. Driving style, as one of the critical aspects of the human factor, and biological behavior, as a factor influencing the performance of individuals, motivate us to examine the relationship between the two.MethodFor this purpose, a test was designed to record the biological signal data, namely, the Electrocardiogram (ECG), Electroencephalogram (EEG), Electromyogram (EMG), and Electrodermal activity (EDA), in a driving simulator with driving events prompting negative emotions. The Multidimensional Driving Style Inventory (MDSI) was employed to determine the driving style of participants.ResultsCorrelation analysis was engaged for data analysis. The results showed, firstly, a significant relationship between the participants’ driving style and their biological behavior and, secondly, the highest correlation between the EEG signal and driving style. Moreover, participants with a nervous and anxious style showed maximum change in biological behavior, while those with a reckless style displayed minimum alterations in biological behavior at the time of unpleasant events during driving.ConclusionConduction of such research can help better understand the behavior of different people while facing unpleasant driving events.     

Peak velocity as a cue in audiovisual synchrony perception of rhythmic stimuli

This study investigated audiovisual synchrony perception in a rhythmic context, where the sound was not consequent upon the observed movement. Participants judged synchrony between a bouncing point-light figure and an auditory rhythm in two experiments. Two questions were of interest: (1) whether the reference in the visual movement, with which the auditory beat should coincide, relies on a position or a velocity cue; (2) whether the figure form and motion profile affect synchrony perception. Experiment 1 required synchrony judgment with regard to the same (lowest) position of the movement in four visual conditions: two figure forms (human or non-human) combined with two motion profiles (human or ball trajectory). Whereas figure form did not affect synchrony perception, the point of subjective simultaneity differed between the two motions, suggesting that participants adopted the peak velocity in each downward trajectory as their visual reference. Experiment 2 further demonstrated that, when judgment was required with regard to the highest position, the maximal synchrony response was considerably low for ball motion, which lacked a peak velocity in the upward trajectory. The finding of peak velocity as a cue parallels results of visuomotor synchronization tasks employing biological stimuli, suggesting that synchrony judgment with rhythmic motions relies on the perceived visual beat.     

Can you see me in the snow? Action simulation aids the detection of visually degraded human motion

Using a novel paradigm, we demonstrate that action simulation can directly facilitate ongoing perception of people's movements. Point-light actors (PLAs) representing common human motions were shown embedded in a visual noise reminiscent of “TV snow”. At first, the PLAs were perceived clearly, then occluded from view for a short duration, during which it was hypothesized that a real-time action simulation was generated tracking the motion's course. The PLA then reappeared in motion at variable visibility against the noise, whilst detection thresholds for the reappearance were measured. In the crucial manipulation, the test motion was either temporally congruent with the motion as it would have continued during occlusion, and thus temporally matching the simulation, or temporally incongruent. Detection thresholds were lower for congruent than for incongruent reappearing motions, suggesting that reappearing motion that temporally matched the internal action simulation was more likely to be detected.     

Flexibility in strategy use: Adaptation of numerosity judgement strategies to task characteristics

In previous investigations we documented that people use several strategies to determine numerosities of blocks that are presented in a square grid. One of these strategies is the clever subtraction strategy, wherein the number of empty squares in the grid is subtracted from the total number of squares in the grid. In the present study we investigated participants' flexibility in strategy use when varying the size of the grids. Results are described in terms of the theoretical framework of Lemaire and Siegler (1995) regarding strategic change, and show that this contextual variable affected the frequency, execution time, and accuracy of subjects' use of the subtraction strategy. The usefulness of this framework for analysing the nature of the adaptation to contextual variations is discussed. From a methodological point of view, this study documents the potential of Beem's (1993, 1999) segmented linear regression models for assessing subjects' strategy use in cognitive tasks.     

Predicting the biological variability of environmental rhythms: Weak or strong anticipation for sensorimotor synchronization?

The internal processes involved in synchronizing our movements with environmental stimuli have traditionally been addressed using regular metronomic sequences. Regarding real-life environments, however, biological rhythms are known to have intrinsic variability, ubiquitously characterized as fractal long-range correlations. In our research we thus investigate to what extent the synchronization processes drawn from regular metronome paradigms can be generalized to other (biologically) variable rhythms. Participants performed synchronized finger tapping under five conditions of long-range and/or short-range correlated, randomly variable, and regular auditory sequences. Combining experimental data analysis and numerical simulation, we found that synchronizing with biologically variable rhythms involves the same internal processes as with other variable rhythms (whether totally random or comprising lawful regularities), but different from those involved with a regular metronome. This challenges both the generalizability of conclusions drawn from regular-metronome paradigms, and recent research assuming that biologically variable rhythms may trigger specific strong anticipatory processes to achieve synchronization.     

Circadian preferences and personality traits: A meta‐analysis

In this study we report results of a meta‐analysis of studies linking personality to circadian rhythms. A total of 35 independent samples, 96 correlations and 8589 participants were included. Results showed that conscientiousness is the personality dimension that mostly related to morningness (r = .29). Agreeableness was also related to morningness although to a lesser degree (r = .13). Openness to experience, extraversion and neuroticism, contribute to a very small degree (i.e. ?.09, ?.06 and ?.07, respectively). Furthermore, moderation analyses suggested effects of personality measure (big five vs. other) and sample (students vs. workers). Average age of participants had no significant impact on the relationship between morningness and personality, apart from a very trivial influence on openness to experience. Copyright © 2010 John Wiley & Sons, Ltd.     

Motion or emotion: Infants discriminate emotional biological motion based on low-level visual information

Infants’ ability to discriminate emotional facial expressions and tones of voice is well-established, yet little is known about infant discrimination of emotional body movements. Here, we asked if 10–20-month-old infants rely on high-level emotional cues or low-level motion related cues when discriminating between emotional point-light displays (PLDs). In Study 1, infants viewed 18 pairs of angry, happy, sad, or neutral PLDs. Infants looked more at angry vs. neutral, happy vs. neutral, and neutral vs. sad. Motion analyses revealed that infants preferred the PLD with more total body movement in each pairing. Study 2, in which infants viewed inverted versions of the same pairings, yielded similar findings except for sad-neutral. Study 3 directly paired all three emotional stimuli in both orientations. The angry and happy stimuli did not significantly differ in terms of total motion, but both had more motion than the sad stimuli. Infants looked more at angry vs. sad, more at happy vs. sad, and about equally to angry vs. happy in both orientations. Again, therefore, infants preferred PLDs with more total body movement. Overall, the results indicate that a low-level motion preference may drive infants’ discrimination of emotional human walking motions.     

Expertise in biological conceptions: The case of the vineyard

To study how expertise impacts the understanding of a complex system like the vineyard, three measures were used with 259 participants (190 non-experts, 34 winemakers and/or winegrowers, and 35 biologists): a questionnaire to check for expertise (the Plant Biology Questionnaire), a task about the Structure, Behaviour and Function model, and a measure of the content of the participants’ discourse with the ALCESTE software. Results showed that biologists mentioned functions significantly more often than behaviours, whereas it was the opposite for winegrowers. Non-experts mentioned functions and behaviours significantly less frequently than experts did. The content analysis confirmed the differential expression of each kind of expertise: scientific wording for biologists, technical wording for winegrowers, and words focused on perceptible structures for the non-experts. Results from all tasks were highly correlated and allowed for an interpretation of expertise in terms of mental models of the vineyard.