A connectionist approach to making the predictability of English orthography explicit to at-risk beginning readers: evidence for alternative, effective strategies.

A case is made (and illustrated with empirical data with children) for connectionist models that are not only computationally explicit but also instructionally explicit. First-graders (N = 128) at the bottom of their classes in reading (average 11.5 percentile on nationally normed tests) participated in a 3-layer intervention. In the first layer, kept constant for all treatment groups, the alphabet principle was taught, making functional spelling units and alternations explicit. In the second layer, which varied systematically across treatment groups, children received different kinds of tutor modeling in learning a set of words of varying spelling-sound predictability, using different connections between printed and spoken words, singly or in combination. In the third layer, also kept constant, children read and discussed illustrated books. Over the 4-month, 24-lesson intervention, all 7 treatment groups in the second layer improved more in word-specific learning than a contact control group that received phonological and orthographic awareness training without explicit instruction on orthographic-phonological connections. Of these 7, only 3 kinds of explicit modeling (whole word, letter-phoneme, and combined whole word and letter-phoneme) resulted in greater transfer to untrained words than the contact control or the other 4 kinds of explicit modeling. Results are discussed in reference to the controversy over whether dual route or connectionist models best account for the acquisition of reading.

Early intervention for reading disabilities: teaching the alphabet principle in a connectionist framework.

Forty-eight children referred by teachers at the end of first grade for difficulty in reading were randomly assigned to three treatments, all of which modeled connections between written and spoken words but did not teach phonics rules, for eight half-hour individual tutoring sessions. The children were taught 48 words of varying orders of spelling-sound predictability (Venezky, 1995) using a whole-word method, for making connections between a word's name and its constituent letters; a subword method, for making connections between each color-coded spelling unit and its corresponding phonemes; or a combined whole-word and subword method. Regardless of the method used, children improved reliably on standardized reading measures and the taught words, showing that they could make connections between written and spoken words at the whole word and subword levels, even when rules were not taught. By posttest, the subword method showed a reliable advantage on a standardized test of real word reading. Knowledge of sounds associated with both multiletter and single-letter spelling units predicted reading achievement. Order of spelling-sound predictability (easy, moderate, difficult) was correlated with standardized measures of reading at pretest and posttest, and the magnitude of the relationship increased as a result of the intervention. Individual differences in verbal intelligence, rapid automatized naming, and phonological and orthographic skills predicted response to the intervention. Instructional implications of the results are discussed.

The dorsal skin-flap model in the rat: factors influencing survival.

Several authors have postulated that the standard McFarlane-type dorsal rat flap model can survive as a graft. Therefore, in an effort to better understand the metabolic support governing the survival of this flap, five flap designs on the dorsal surface of the rat were studied. Each was manipulated to control progressively for the metabolic support to the flap by means of skin-graft and/or skin-flap physiology. The flap designs included (1) a standard McFarlane flap (n = 10), (2) a full-thickness "flap" graft (n = 10), (3) a McFarlane flap separated from the bed with plastic sheeting (n = 9), (4) a McFarlane flap separated from the bed by closing the wound beneath the flap (n = 29), and (5) flaps raised as in group 4 after a 2-week delay procedure (n = 9). Based on direct comparisons of both the pattern of necrosis and the surviving surface area in each group, we conclude that (1) the distal aspect of the dorsal rat flap can survive as a graft when in contact with the underlying bed, (2) the "take" of the flap as a graft is variable, and (3) to serve as a reasonable indicator of human flap behavior, the skin-graft effect must be controlled for by separating the flap from the underlying bed.

The effect of occlusion on the survival of an isolated dorsal skin flap in the rat.

Previous studies have documented that maintenance of a moist environment can increase flap survival in the rat model. However, the distal aspect of the dorsal rat flap can survive as a graft, a fact that masks the behavior of this tissue as a flap, thereby making previous studies difficult to interpret. Using a dorsal rat flap model designed to control for the skin graft variable, the effect of occlusive dressings on flap survival was determined. In two groups of rats (n = 10), treatment with a semipermeable occlusive dressing was compared with no treatment. In both groups, 2 x 7-cm flaps based caudally were raised on the dorsum of each rat and the wound closed beneath the flap to prevent take of the flap as a graft. No significant difference in surviving flap surface area was noted (p greater than 0.2). We conclude that, although a moist environment may enhance wound healing, it will not improve the survival of an ischemic flap.