Generic instruction versus intensive tact instruction and the emission of spontaneous speech.

Introduction The expansion of the tact repertoire appears to be critical to the acquisition of subsequent and more complex verbal developmental stages. It is likely that direct instruction in tacts must continue until children have acquired the verbal developmental cusp of Naming, which is defined as the capability to acquire the listener and speaker responses to stimuli incidentally (Greer & Speckman, 2009; Greer, Stolfi, & Pistoljevic, 2007; Horne & Lowe, 1996; Pistoljevic & Greer, 2006; Skinner, 1957). Skinner (1957) described six elementary verbal functions for the speaker, including (1) echoics, (2) mands, (3) tacts, (4) autoclitics, (5) intraverbals, and (6) textual responding. For the purposes of this study, we focus primarily on mands, tacts, and intraverbals. Mands are speaker or substitute speaking topographies that are emitted under conditions of deprivation or annoying conditions in the presence of a listener who then mediates the environment for the speaker (Skinner, 1957; Greer & Ross, 2008). Tacts are verbal operants occasioned by a discriminative stimulus in the environment and are reinforced by generalized reinforcers particularly attention (Tsiouri & Greer, 2003). Children with autism usually demonstrate deficits in functional communication (DSM-IV, American Psychiatric Association, 1994) , including tacts. For example, children with autism typically do not emit language without prompting or questioning by others and thus demonstrate few instances of "spontaneous speech" (Krantz & McClannahan, 1998). For this reason, studies have focused on the development of verbal skills by these children. Partington, Sundberg, Newhouse, & Spengler (1994) implemented a procedure for transferring stimulus control from verbal stimuli to nonverbal stimuli in a six-year-old girl with autism. As a result, the girl acquired tact responses to 19 stimuli. Partington et al. then proposed that the reason for the failure of children with autism to acquire tacts may be tied to the antecedent verbal behavior of others (e.g., "What is that? ") which functions to block the establishment of stimulus control by a nonverbal stimulus. This observation is consistent with findings reported by Williams and Greer (1993). Several evidence-based protocols are available for inducing echoics and then mand and tact responses for children who have no, or limited, vocal verbal operants. Included here are (1) the stimulus-stimulus pairing procedure to induce echoics (Sundberg, Michael, Partington, & Sundberg, 1996), (2) rapid motor imitation to induce echoics to mand and echoics to tact functions (Ross & Greer, 2003; Tsiouri, & Greer, 2003), and (3) direct echoic to mand and echoic to tact instruction (Williams & Greer, 1993). Procedures are also available to expand repertoires such as speaker immersion (Greer & Ross, 2004; Ross, Nuzzolo, Stolfi, & Natarelli, 2006; Schwartz, 1994). However, once repertoires are established, children need extensive instruction in order to expand their language functions or verbal repertoires. The primary repertoire in need of expansion is the tact repertoire because tacts are foundational to the subsequent development of more complex verbal behavior such as Naming, say-do correspondence, conversational units, and age-appropriate self-talk (Barnes-Holmes, Barnes-Holmes, & Cullinan, 2000; Greer & Ross, 2008; Greer & Speckman, 2009; Horne & Lowe, 1996). Several recent investigations suggested the importance of directly and intensely teaching the tact repertoire, especially for those children who cannot acquire tacts through spontaneous observational learning (Williams & Greer, 1993; Ross & Greer, 2003; Schauffler, & Greer, 2006; Tsiouri & Greer, 2003; Pistoljevic & Greer, 2006; Pistoljevic, 2008). The protocol used in these studies is referred to as the intensive tact procedure (ITP). …