Exploratory environments

Chapter 5 shows how schema theory can be practically implemented. It gives a detailed description of one example of schema-based instruction, the Story Problem Solver (SPS). SPS is a computer-based system of instruction constructed around schema theory, using the basis set of schemas developed in chapter 3. It provides fundamental instruction enabling students to build schemas. A second computer program, the Problem Solving Environment (PSE), is also described in chapter 5. PSE provides an exploratory environment in which students can practice and utilize their schema knowledge about story problems. 

I have used the term "directed activities" to refer to the two types of activities at the left-most part of the spectrum (namely drill and practice activities and tutorials). I have lumped the other activities under the term "exploratory environments." There are not always sharp boundaries between the types of activities. In addition, many software packages incorporate several types of computer-based learning activities. 

Exploratory environments, marked by considerable learner controL are generally characterized by several features ... 

Taylor DH, Lagory KE, Zaccaro DJ, et al. 1985. Effect of trichloroethylene on the exploratory and locomotor activity of rats exposed during development. Sci Total Environ 47 415-420. 

Most of these models evaluate the effects of drugs on the behaviour of animals when they are exposed to a novel environment. Novelty normally reduces animals exploratory activity but established anti-anxiety drugs consistently increase exploration of, and approaches to, the novel stimulus and reduce the neophobic ( avoidance ) reaction. There are several examples of tests based on this principle (Table 19.2) but two that are widely used are the plus-maze and the social interaction tests. 

Similar to LSD and other monoamine hallucinogens, mescaline suppresses locomotor and exploratory behavior in novel environments (Wing et al. 1990). Also similar to LSD, tolerance develops to the behavioral effects of chronic doses of mescaline (Murray et al. 1977). Mescaline increases aggression in rat models (Sbordone et al. 1978) however, this is an elicited aggression (by electric shock) and does not necessarily generalize to human behavior. Increased aggression is not characteristic of humans using mescaline. 

Studies in mice with a targeted inactivation of other 5-HT receptor sub-types, such as the S-HTsa and 5-HT7, or a transgenic line that overexpresses 5-HT3, demonstrate that these receptors modulate the activity of neural circuits involved specifically in exploratory and reward-related behavior. When exposed to novel environments, KO mice lacking the S-HTsa exhibit increased exploratory activity and an attenuated stimulatory effect of lysergic acid diethylamide (LSD) on exploratory activity but no change in anxiety-related behavior (Grailhe et al. 1999), whereas S-HTy KO mice do not express any overt behavioral phenotype at all (Hedlund et al. 2003). 

The behavior of tacl mice was also analyzed in several animal models of anxiety. The open-field test is a widely used tool for behavioral research, but less specific for the evaluation of the anxiety state of the animal, because it is a summation of the spontaneous motor and the exploratory activities, and only the latter is influenced by the anxiety level (Choleris et al. 2001). Under aversive environmental conditions (high level of illumination) the animals activity is strongly affected by the emotional state, while less aversive situations (familiar, dimly lit environment) are useful to assess the general motor activity of mice. Because rodents avoid open areas, the activity of mice in the central part of the open-field arena is inversely correlated to the anxiety level. Tad mice spent only 6.5% of their total activity in the central part, which represented 11% of the total field, indicating that they avoided this aversive area, hi contrast, tacl mice spent 13.6% of their activity in the central area (Bilkei-Gorzo et al. 2002). The increased central activity of the tad mice indicates that the test situation was anxiogenic for tad animals, but less so for the knockout mice. 

The rule of the K nearest objects, KNN, has been used in classification problems, in connection and comparison with other methods. Usually KNN requires a preliminary standardization and, when the number of objects is large, the computing time becomes very long. So, it appears to be useful in confirmatory/exploratory analysis (to give information about the environment of objects) or when other classification methods fail. This can happen when the distribution of objects is very far from linear, so that the space of one category can penetrate into that of another, as in the two-dimensional example shown in Fig. 28, where the category spares, computed by bayesian analysis or SIMCA, widely overlap. 

An initial phase of attending to the environment or to the problem, which is the exploratory, pre-decision stage when information is sought and alternatives explored [the attending phase) ... 

Exploratory behaviour Distinct exploratory behaviour Rooting with the snout Rich and diverse environment Provision of materials for rooting... 

Morawska L, Thomas S, Hofmann W, Ristovski Z, Jamriskaa M, Rettenmoser T, Kagerer S (2004) Exploratory cross-sectional investigations on ambient submicrometer particles in Salzburg, Austria. Atmos Environ 38 3529-3533... 

Burton, and F.J. de Serres. Exploratory monitoring of air pollutants for mutagenicity activity with the Tradescantia stamen hair system. Environ. Health Perspect. 27 51-60, 1978. 

Salou, J., Tauler, R., Bayona, J., and Tolosa, I., Input characterization of sedimentary organic chemical markers in the northwestern Mediterranean Sea by exploratory data analysis, Environ. Sci. Technol., 31, 3482-3490, 1997. 

The importance of ventral striatal DA in the locomotor response to psychostimulants was demonstrated by current classic studies showing that manipulating ventral striatal DA transmission by lesion (Kelly and Iversen, 1976) or local infusion of DA receptor antagonists impairs while local infusion of DA receptor agonists (Pijenburg et al., 1976) evokes forward locomotion and exploratory behavior in a novel environment. Subsequent studies have attempted to establish which one among the main subdivisions of the ventral striatum (NAc shell, NAc core, olfactory tubercle) could be responsible for this function. This issue, however, is highly controversial. 

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