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51.
We know relatively little about the development of disruptive behaviors (DBs), and gender differences therein. The objective of this study was to describe the continuity and discontinuity in the degree to which young children in the general population are reported to exhibit specific DBs over time. Data came from the Québec Longitudinal Study of Child Development. First, the results show that relatively few children exhibit DBs on a frequent basis at 41 months of age. Second, the results show that a majority of children who exhibit a particular DB on a frequent basis at 41 months of age did not do so 1 year earlier. In addition, a majority of children who exhibited a particular DB on a frequent basis at 29 months of age no longer do so 1 year later. Third, gender differences in DBs (boys > girls) are either emerging or at least increasing in magnitude between 29 and 41 months of age. Consistent with the canalization of the behavioral development principle, children who exhibited DBs on a frequent basis at 29 months of age are less likely to stop doing so in the following year if they had exhibited the same behaviors at 17 months of age.  相似文献   
52.
Physical activity impacts functional recovery following stroke in humans, however its effects in experimental animals submitted to chronic cerebral hypoperfusion have not been investigated. The aim of this study was to evaluate the therapeutic potential of exercise, as assessed by cognitive activity in the Morris water maze and the brain oxidative status, through measurement of macromolecules damage, TBARS levels and total cellular thiols, as well as antioxidant enzymes in hippocampus, striatum and cerebral cortex. Adult male Wistar rats were submitted to the modified permanent bilateral occlusion of the common carotid arteries (2VO) method, with right common carotid artery being first occluded, and tested 3 months after the ischemic event. The effects of three different exercise protocols were examined: pre-ischemia, post-ischemia and pre+post-ischemia. Physical exercise consisted of sessions of 20-min, 3 times per week during 12 weeks (moderate intensity). Rats were submitted to cognitive assessment, in both reference and working spatial memory and after the last testing session were sacrificed to have oxidative stress parameters determined. Hypoperfusion caused a significant cognitive deficit in both spatial water maze tasks and this effect was reversed in rats receiving exercise protocol post and pre+post the ischemic event. Moreover, forced regular treadmill exercise regulated oxidative damage and antioxidant enzyme activity in the hippocampus. These results suggest that physical exercise protects against cognitive and biochemical impairments caused by chronic cerebral hypoperfusion.  相似文献   
53.
Assessing implicit learning in the continuous pursuit-tracking task usually concerns a repeated segment of target displacements masked by two random segments, as referred to as Pew’s paradigm. Evidence for segment learning in this paradigm is scanty and contrasts with robust sequence learning in discrete tracking tasks. The present study investigates this issue with two experiments in which participants (N = 56) performed a continuous tracking task. Contrary to Pew’s paradigm, participants were presented with a training sequence that was continuously cycled during 14 blocks of practice, but Block 12 in which a transfer sequence was introduced. Results demonstrate sequence learning in several conditions except in the condition that was obviously the most similar to previous studies failing to induce segment learning. Specifically, it is shown here that a target moving too slowly combined with variable time at which target reversal occurs prevents sequence learning. In addition, data from a post-experimental recognition test indicate that sequence learning was associated with explicit perceptual knowledge about the repetitive structure. We propose that learning repetition in a continuous tracking task is conditional on its capacity to (1) allow participants to detect the repeated regularities and (2) restrict feedback-based tracking strategies.  相似文献   
54.
The “evoking freedom” technique is a verbal compliance procedure that solicits someone to comply with a request by simply telling them they are free to accept or to refuse the request. The measure of the efficiency of this technique on compliance with large samples and the evaluation of its influence on various requests was tested in the first set of experiments. This technique was found to be efficient in increasing the number of people who agreed to give money to a requester, the number of smokers who agreed to give a cigarette, passersby who agreed to respond to a survey, and homeowners who agreed to buy pancakes. In the second set of experiments in which the mode of interaction between the requester and the person solicited was tested, the “evoking freedom” technique was found to be associated with greater compliance with a request addressed by mail and through face‐to‐face, phone‐to‐phone, or computer‐mediated interaction. The third set of experiments tested the effect of semantic variations of the “evoking freedom” technique and the weight of the repetition of the semantic evocation of freedom. These later experiments that used various phrases evoking the freedom to comply were found to be associated with greater compliance. Moreover, a double evocation of freedom was associated with even greater compliance than a single evocation. The importance of this technique for commitment communication is discussed.  相似文献   
55.

Purpose

This study illustrates complementary variable- and person-centered approaches allowing for a more complete investigation of the dimensionality of psychometric constructs. Psychometric measures often assess conceptually related facets of global overarching constructs based on the implicit or explicit assumption that these overarching constructs exist as global entities including conceptually related specificities mapped by the facets. Proper variable- and person-centered methodologies are required to adequately reflect the dimensionality of these constructs.

Design/Methodology/Approach

We illustrate these approaches using employees’ (N = 1077) ratings of their psychological wellbeing at work.

Findings

The results supported the added value of the variable-centered approach proposed here, showing that employees’ ratings of their own wellbeing simultaneously reflect a global overarching wellbeing construct, together with a variety of specific wellbeing dimensions. Similarly, the results show that anchoring person-centered analyses into these variable-centered results helps to achieve a more precise depiction of employees’ wellbeing profiles.

Implications

The variable-centered bifactor exploratory structural equation modeling (ESEM) framework provides a way to fully explore these sources of psychometric multidimensionality. Similarly, whenever constructs are characterized by the co-existence of overarching constructs with specific dimensions, it becomes important to properly disaggregate these two components in person-centered analyses. In this context, person-centered analyses need to be clearly anchored in the results of preliminary variable-centered analyses.

Originality/Value

Substantively, this study proposes an improved representation of employees’ wellbeing at work. Methodologically, this study aims to pedagogically illustrate the application of recent methodological innovations to organizational researchers.
  相似文献   
56.
This study investigated the extent to which trait anxiety and state anxiety in response to stress are associated with the cortisol awakening response (CAR).Fifty-one healthy participants were recruited. State anxiety measures were taken in anticipation of and during a laboratory stressor. Salivary cortisol levels were measured immediately upon awakening (at 0, 15, 30, and 45 min) on two consecutive mornings. Cortisol awakening response was assessed by the area under the curve with respect to zero (AUCG).The magnitude of the CAR was found to be negatively associated with both trait anxiety and anticipatory anxiety. Moreover, regression analysis showed that the effects of trait anxiety on the AUCG were mediated by anticipatory anxiety.These results suggest that the CAR is influenced by trait anxiety. Moreover, the effect of trait anxiety on the CAR seems to operate by impacting on psychological stress reactivity (i.e., anticipatory anxiety).  相似文献   
57.
Pattern recognition lies at the heart of the cognitive science endeavor. In this paper, we provide some criticism of this notion, using studies of chess as an example. The game of chess is, as significant evidence shows, a game of abstractions: pressures; force; open files and ranks; time; tightness of defense; old strategies rapidly adapted to new situations. These ideas do not arise on current computational models, which apply brute force by rote-memorization. In this paper we assess the computational models of CHREST and CHUMP, and argue that chess chunks must contain semantic information. This argument leads to a new and contrasting claim, as we propose that key conclusions of Chase and Simon's (1973) influential study stemmed from a non-sequitur. In the concluding section, we propose a shift in philosophy, from “pattern recognition” to a framework of “experience recognition”.  相似文献   
58.
Although the cholinergic system has long been implicated in the formation of memory, there had been no direct demonstration that activation of this system can actually induce specific behavioral memory. We have evaluated the "cholinergic-memory" hypothesis by pairing a tone with stimulation of the nucleus basalis (NB), which provides acetylcholine to the cerebral cortex. We found that such pairing induces behaviorally-validated auditory memory. NB-induced memory has the key features of natural memory: it is associative, highly-specific and rapidly induced. Moreover, the level of NB stimulation controls the amount of detail in memory about the tonal conditioned stimulus. While consistent with the hypothesis that properly-timed release of acetylcholine (ACh) during natural learning is sufficient to induce memory, pharmacological evidence has been lacking. This study asked whether scopolamine, a muscarinic antagonist, impairs or prevents the formation of NB-induced memory. Adult male rats were first tested for responses (disruption of ongoing respiration) to tones (1-15 kHz), constituting a pre-training behavioral frequency generalization gradient (BFGG). Then, they received a single session of 200 trials of a tone (8.00 kHz, 70 dB, 2 s) paired with electrical stimulation of the NB (100 Hz, 0.2 s). Immediately after training, they received either scopolamine (1.0 mg/kg, i.p.) or saline. Twenty-four hours later, they were tested for specific memory by obtaining post-training BFGGs. The saline group developed CS-specific memory, manifested by maximum increase in response specific to the CS frequency band. In contrast, the scopolamine group exhibited no such memory. These findings indicate that NB-induced specific associative behavioral memory requires the action of intrinsic acetylcholine at muscarinic receptors, and supports the hypothesis that natural memory formation engages the nucleus basalis and muscarinic receptors.  相似文献   
59.
Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n = 5) or Unpaired (n = 5) with weak electrical stimulation (~48 μA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion.  相似文献   
60.
Specific behavioral associative memory induced by stimulation of the cortically-projecting cholinergic nucleus basalis (NB) is dependent on intrinsic acetylcholine and shares with natural memory such features as associativity, specificity, rapid formation, consolidation and long-term retention. Herein, we examined extinction and the effects of stimulus pre-exposure. Two groups of adult male rats (n = 4 each) were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), constituting a pre-training behavioral frequency generalization gradient (BFGG). They next received a first session of training, 200 trials of a tone (8.00 kHz, 70 dB, 2 s) either paired with electrical stimulation of the NB (100 Hz, 0.2 s, ~67 μA, NBstm) (group IP) or unpaired (group IU). Twenty-four hours later, they were tested for behavioral memory by obtaining post-training BFGGs. Then the contingencies were reversed yet another 24 h later; the IP group received tone and NBstm unpaired and the IU group received them paired. A final set of generalization gradients was obtained the next day. All stimuli were presented with subjects under state control indexed by regular respiration. Tested 24 h post-initial training, the IP group developed specific associative behavioral memory indicated by increased responses only to CS-band frequencies, while the IU group did not. After subsequent training with unpaired stimuli, the IP group exhibited experimental extinction. Furthermore, after initial exposure to the CS and NBstm unpaired, the IU group exhibited a tendency toward reduced conditioning to CS/NBstm pairing and a significant increase in latency of conditioned responses. The present findings provide additional support for the hypothesis that engagement of the NB is sufficient to induce natural associative memory and suggest that activation of the NB may be a normal component in the formation of natural associative memory.  相似文献   
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