Early visual and motor experience as determiners of complex maze-learning ability under rich and reduced stimulation.

The Characteristics and Context of Imprinting

“…The experiments of Lawrence (1949Lawrence ( , 1950, Gibson & Walk (1956), and Forgus (1956), among many others, showed that, regardless of the response which they are required to give, animals are better able to learn a discrimination if they have had previous experience with one or more of the discriminanda. At the time when Lorenz first suggested that this consequence of imprinting distinguishes it from other learning processes, theorists supposed that in the course of learning a specific response becomes 'attached' to a specific stimulus.…”

"Visual" and "visual-motor" experience: A replication.

“…The second group is reared in a similar cage but they are restricted to the center portion of it by the insertion of clear plastic sides: they can see the objects around the cage, but they cannot have the same motor experience with them ("visual" experience). A rather surprising result of these experiments is the differential transfer often observed, the visual group being superior on form discriminations (2) and elevated mazes on trials in the light (3), while the visual-motor group is superior when visual stimulation is reduced (3,4). This differential transfer is, to some extent, contrary to Hebb's position (S), which would favor general superiority of the visual-motor group because of broader experience in both modalities.…”

“…Fergus has demonstrated a distinction between "visual" and "visual-motor" prior experience in a series of experiments (2,3,4). The general technique has been to rear one group of animals in a large cage where they are given the opportunity to see and have commerce with objects placed around the cage ("visualmotor" experience).…”

Effects of environmentally differential rearing upon maze performance in prenatally irradiated microcephalic rats

“…The enrichment effects include an increase of glia cells (Diamond et al, 1966), dendritic branching and spines (Holloway, 1966;Volkmar and Greenough, 1972;Globus et al, 1973;Greenough et al, 1973), area of synaptic contact (Diamond et al, 1967;Greenough et al, 1973), and neuron size (Diamond et al, 1967). Beneficial effects of enriched condition (EC) on learning ability have also been confirmed (Forgays and Forgays, 1952;Forgus, 1955;Krech et al, 1962), and Davenport (1976) has proposed an "environmental therapy" for the behavioral alleviation in experimentally disadvantaged animals such as perinatally thyroiddeficient rat. In a pre%ous study ) the present authors have examined the validity of environmental therapy in prenatally X-irradiated m i m p h a l i c rats (200 rads on day 17 of gestation). The results showed that beneficial effects of EC rearing were virtually unobservable, apd enrichment-facilitatd performance was observed only in a limited aspect such as the first trial scores in these highly microcephalic rats.…”