JOURNAL OF APPLIED BEHAVIOR ANALYSIS

2014, 47, 710–722

NUMBER

4 (WINTER)

ANALYSIS OF SELF-FEEDING IN CHILDREN WITH FEEDING DISORDERS KRISTI M. RIVAS, CATHLEEN C. PIAZZA, HENRY S. ROANE, VALERIE M. VOLKERT, VICTORIA STEWART, HEATHER J. KADEY, AND REBECCA A. GROFF UNIVERSITY OF NEBRASKA MEDICAL CENTER’S MUNROE-MEYER INSTITUTE

In the current investigation, we evaluated a method for increasing self-feeding with 3 children with a history of food refusal. The children never (2 children) or rarely (1 child) self-fed bites of food when the choice was between self-feeding and escape from eating. When the choice was between selffeeding 1 bite of food or being fed an identical bite of food, self-feeding was low (2 children) or variable (1 child). Levels of self-feeding increased for 2 children when the choice was between selffeeding 1 bite of food or being fed multiple bites of the same food. For the 3rd child, self-feeding increased when the choice was between self-feeding 1 bite of food or being fed multiple bites of a less preferred food. The results showed that altering the contingencies associated with being fed increased the probability of self-feeding, but the specific manipulations that produced self-feeding were unique to each child. Key words: choice, concurrent operants, feeding disorder, food refusal, food selectivity, pediatric feeding disorders, response effort, self-feeding

Much is known about the developmental progression of self-feeding skills in children who eat typically (e.g., Carruth, Ziegler, Gordon, & Hendricks, 2004). For example, before 7 months of age, most children who eat typically are bottle and spoon fed by a caregiver. The vast majority of children who eat typically will use their hands to grasp pieces of food by 7 to 11 months of age and will eat with a spoon by 19 to 24 months, and this progression will occur in the absence of formalized intervention (Carruth & Skinner, 2002). Surprisingly little is known, however, about the emergence of self-feeding in children who have been diagnosed with feeding disorders. That is, does self-feeding emerge in children with feeding disorders in the absence of formalized intervention as it does in typically eating children, or is the motivation to self-feed affected by their historical avoidance of eating? One way of answering this question is to examine variables that affect the responding of Address correspondence to Cathleen C. Piazza, MunroeMeyer Institute, University of Nebraska Medical Center, 985450 Nebraska Medical Center, Omaha, Nebraska 68198 (e-mail: [email protected]). doi: 10.1002/jaba.170

children with feeding disorders (e.g., Cooper et al., 1999; Kerwin, Ahearn, Eicher, & Burd, 1995; Vaz, Volkert, & Piazza, 2011). For example, Kerwin et al. (1995) evaluated the effects of response effort on levels of acceptance and consumption in children with feeding disorders. In Study 1, the feeder presented the child with varying amounts of food on a spoon, which was conceptualized as the response-effort manipulation, and acceptance resulted in access to toys and praise. In general, as response effort increased with increasing food volume, the probability of eating decreased and the probability of refusal increased. In Study 2, feeders used putative escape extinction in the form of nonremoval of the spoon or physical guidance to increase acceptance. Kerwin et al. hypothesized that implementation of escape extinction increased the aversiveness of refusal. As the aversiveness of refusal increased, the probability of refusal decreased, and the probability of eating increased. Vaz et al. (2011) applied the same conceptual framework used by Kerwin et al. (1995) to increase the self-feeding of one child with a history of food selectivity. In baseline, the child did not eat when he had the choice of feeding

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SELF-FEEDING himself a target food or engaging in refusal behavior. Following baseline, Vaz et al. identified several low-preference foods, called avoidance foods, which the feeder used in the treatment manipulation. During treatment, self-feeding increased when the child had the choice of feeding himself one bite of a target food or having the caregiver feed him one bite of the target food and five bites of an avoidance food. Vaz et al. (2011) conceptualized their manipulation in terms of the response effort and quality of reinforcement associated with responding. The response-effort manipulation was that self-feeding was associated with consumption of a single bite of food and being fed was associated with consumption of six bites of food. Consistent with Kerwin et al. (1995), Vaz et al. hypothesized that the larger volume of food was more effortful to consume because it required more responses. The qualitative manipulation was that self-feeding was associated with consumption of the relatively more preferred target food and being fed was associated with the relatively less preferred avoidance food. The limitation of Vaz et al. was that the necessity of both the response-effort and quality manipulations to increase self-feeding was unclear. In the current investigation, we extended the results of Kerwin et al. (1995) and Vaz et al. (2011) by evaluating a method for increasing selffeeding with three children with a history of food refusal. Before this investigation, we treated these children’s feeding problems with nonremoval of the spoon with the caregiver feeding the child. Next, we gave each child the opportunity to self-feed or to escape eating, and all children frequently chose to escape eating and infrequently chose to self-feed. We then eliminated escape from eating and gave the child a choice between being fed and self-feeding. Under this arrangement, the children did not self-feed consistently. We then manipulated the number of bites (Study 1) or the number of bites and type of food (Study 2) associated with being fed until the child’s responding shifted from preference for being fed to preference for self-feeding.

711 METHOD

Participants, Setting, and Materials Three children who had been admitted to an outpatient pediatric feeding disorders program participated. A goal of the admission was to increase self-feeding, which was the focus of the current investigation. Based on direct observation and caregiver report, all children had the skills to self-feed, but none self-fed consistently at home or in the clinic. The participants were Tina, Seth, and Brian for Experiment 1 and Brian for Experiment 2. Tina was a 3-year-old girl who had been diagnosed with status post short-gut syndrome secondary to gastroschisis, which resulted in a small-bowel transplant. Before admission, she was 100% dependent on gastrostomy (G-) tube feeding and parenteral nutrition; she consumed nothing by mouth. Seth was a 3-year-old boy who had been diagnosed with gastroesophageal reflux disease and failure to thrive. Before admission, he was 100% dependent on G-tube feeding; he consumed nothing by mouth. Brian was a 2.5-yearold boy who had been diagnosed with pervasive developmental disorder not otherwise specified and no other significant medical history. Before admission, he consumed most types of Stage 2 and 3 jarred baby foods except vegetables. He refused foods of any other texture. He received 100% of his liquids via baby bottle. Sessions for Tina and Seth were conducted in the clinic in rooms (4 m by 4 m) with one-way observation panels and sound monitoring. Sessions for Brian were conducted in the home, and sessions were observed via telehealth. Materials included utensils, bowls, seating equipment, food trays, gloves, timers, and laptop computers. Response Measurement and Reliability Observers used laptop computers to score selffed acceptance for each bite presentation when the child picked up the spoon of food and placed the entire bite past the plane of the lips and into the mouth within 5 s (Tina) or 30 s (Seth and

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Brian) of the initial presentation. We decreased the time requirement for self-fed acceptance for Tina because we observed that Seth and Brian sometimes waited until the end of the 30-s interval to self-feed the bite. Therefore, we shortened the latency for Tina to decrease the interpresentation interval and prevent long pauses in this interval, which made the meal more efficient. (We conducted the self-feeding analysis with Seth and Brian before we conducted it with Tina.) Observers scored a presentation when the caregiver placed a bowl with the spoon of food in front of the child. Data for self-fed acceptance were converted to a percentage after dividing occurrences of self-fed acceptance by number of presentations. During the food preference assessment (Brian only), observers scored consumption when Brian had no food larger than a pea in his mouth 30 s after the entire bite entered the mouth, unless the absence of food in the mouth was due to expulsion (spitting out the food). Observers scored avoidance when Brian contacted the feeder’s hand or arm or the spoon, covered his mouth, or engaged in negative vocalizations such as screaming, crying, or saying “get it away” while the feeder presented the bite. Two observers recorded data simultaneously but independently during 75%, 24%, and 45% of self-feeding sessions for Tina, Seth, and Brian, respectively, and 100% of stimulus preference assessment trials for Brian. We calculated occurrence agreement as occurrence agreements (both observers scored a self-fed acceptance) divided by occurrence agreements plus disagreements (one observer scored and the other did not score a self-fed acceptance) and converted this ratio to a percentage. We calculated nonoccurrence agreement as nonoccurrence agreements (both observers did not score a self-fed acceptance) divided by nonoccurrence agreements plus disagreements and converted this ratio to a percentage. We calculated total agreement as agreements divided by agreements plus disagreements and converted the ratio to a percentage. For self-fed acceptance,

occurrence agreement was 87%, 87%, and 98%; nonoccurrence agreement was 83%, 88%, and 98%; and total agreement was 92%, 93%, and 99% for Tina, Seth, and Brian, respectively. For the stimulus preference assessment, we calculated agreement as occurrence (both observers scored the behavior during the trial) plus nonoccurrence (both observers did not score the behavior during a trial) agreements divided by occurrence plus nonoccurrence agreements plus disagreements and converted this ratio to a percentage. Mean interobserver agreement was 97% for consumption and 100% for avoidance for Brian during the stimulus preference assessment. General Procedure Tina’s and Seth’s mothers and Brian’s paternal grandmother served as feeders and are henceforth referred to as caregivers. Before this analysis, children received feeding treatment in intensive outpatient and outpatient clinics (Tina and Brian) and day-treatment and outpatient clinics (Seth) for 10, 7, and 4.5 months for Tina, Seth, and Brian, respectively. As a result, we had conducted caregiver training on feeding protocol implementation for approximately 174, 45, and 74 hr with the caregivers of Tina, Seth, and Brian, respectively, before the initiation of the selffeeding analysis. Caregivers selected target foods before the start of the analysis from a list of 68 possible foods. Target foods were the focus of the self-feeding analysis; that is, they were the foods that the caregiver wanted the child to self-feed. The target foods were carrots, chicken nuggets, green beans, hot dogs, mashed potatoes, sweet potatoes, and tuna for Tina; bread, broccoli and cheese, carrots, cheese, chicken, green beans, hot dogs, mashed potatoes, peaches, pears, and waffles for Seth; and baked beans, baked potato, bananas, carrots, chicken, corn, green beans, macaroni and cheese, mandarin oranges, mashed potatoes, peaches, pears, rice, scrambled eggs, soup beans, and spaghetti in Study 1 and the same foods except for scrambled eggs in Study 2 for Brian.

SELF-FEEDING Children participated in weekly 1- to 1.5-hr appointments. During each appointment, caregivers conducted multiple five-bite sessions with brief breaks between sessions. The mean number of self-feeding sessions conducted per appointment was 4.4 for Tina, 3.8 for Seth, and 8.8 for Brian. Before each appointment, the therapist who coordinated the treatment selected at least four foods from the list of caregiver-identified target foods to present during sessions. The therapist ensured that the caregiver presented every target food in each phase of the analysis with approximately equal numbers of presentations of each food within the phase. The therapist told the caregivers which foods to bring to the appointment. For Tina, the caregiver presented the same four target foods in each session, with at least one food from the food groups of protein, starch, and vegetable (e.g., chicken, potatoes, green beans, tuna) because she could not eat fruit due to her medical condition. For Seth and Brian, one target food from the food groups of protein, starch, fruit, and vegetable (e.g., chicken, potatoes, peaches, green beans) were presented. The caregiver presented target foods in a random order across sessions. The texture of presented food was pureed table food for Tina and Seth and finely chopped table food for Brian. The bolus volume for target and avoidance foods (Brian only) was 1.75 cc on a small Maroon spoon for Tina, 2 cc on a toddler spoon for Seth, and 4 cc on a toddler spoon for Brian. These were the textures, utensils, and bolus sizes we had presented in the previous treatment of the child’s feeding problem. Before the start of sessions, the caregiver explained the contingencies to the child (e.g., “If you take your bite, I will say, ‘good job.’ If you don’t take your bite, I will feed you two bites of the same food.”). Explanation of the contingencies occurred once per appointment unless the contingencies changed during the appointment. In this case, the caregiver explained the new contingencies to the child before beginning sessions with the changed contingencies. During

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each five-bite session, the caregiver presented three of the foods once and one of the foods twice, one bite at a time. The caregiver presented the bite by placing a spoon with food in a bowl on a table or tray in front of the child accompanied by a prompt to “take a bite” approximately every 30 s if the child did not self-feed the bite or 30 s after the previous bite entered the child’s mouth. The caregiver delivered praise (e.g., “Good job taking your bite”) after self-fed acceptance. After the bite entered the child’s mouth, the caregiver activated a timer for 30 s. When the 30-s interval elapsed, the caregiver implemented a mouth check by saying “show me” while modeling an open mouth. If the child did not open his or her mouth in response to the verbal and model prompt, the caregiver used a rubber-coated baby spoon to prompt the child to open his or her mouth by inserting the spoon just past the plane of the child’s lips and turning the spoon 90°. The caregiver delivered praise (e.g., “Good job swallowing your bite”) if no food larger than a pea was in the child’s mouth after the first 30-s check for each bite and then presented the next bite. The caregiver did not provide praise if the absence of food was due to expulsion. The caregiver delivered a prompt to “finish swallowing your bite” if the child had food larger than a pea in his or her mouth at the 30-s check and then immediately presented the next bite. If the child was packing, which was defined as food larger than a pea in the mouth at the 30-s check, the caregiver conducted checks after the caregiver had presented the last (fifth) bite of the session and prompted the child to swallow every 30 s until no food larger than a pea remained in the child’s mouth. General baseline procedure. The purpose of the baseline was to establish levels of self-fed acceptance when the child had the choice of selffeeding or refusing the bite of target food. The caregiver followed the general procedure. If the child did not self-feed the bite, the bowl remained on the table or tray for 30 s. After 30 s, the caregiver removed the bowl and presented the next bite.

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General treatment procedure. The caregiver followed the general procedure with the following modifications. If the child did not self-feed the bite, the caregiver used nonremoval of the spoon with re-presentation of expelled bites (Hoch, Babbitt, Coe, Krell, & Hackbert, 1994) to feed the number and type of foods specified by the arranged contingency described below. During nonremoval of the spoon, the caregiver held the spoon at the child’s lips until she could deposit the bite into the child’s mouth. In conditions in which the caregiver fed the child multiple bites consecutively, she fed the child the bite that was in the bowl in front of the child and the additional bites from a bowl of identical target food located on a table next to her. She fed the bites one after the other and activated the mouth-check timer after the prescribed number and type of bites had entered the child’s mouth. The caregiver re-presented expelled bites each time an expulsion occurred. During re-presentation, the caregiver used the spoon to scoop up the expelled food from the child’s face or bib and placed it back into the child’s mouth using the nonremoval procedure. If the caregiver could not re-present the bite that had been in the child’s mouth (e.g., it fell on the floor), the caregiver obtained food from the bowl for the representation. If the caregiver had to re-present food from the bowl, she estimated the amount of food that the child expelled and re-presented the estimated amount. If the child expelled more than one food type (e.g., tuna and peas at the same time), the caregiver obtained a small amount of each food type from the bowls until the total bolus equaled the estimated amount of food that had been expelled. The caregiver continued to re-present the expelled bite until the child swallowed. Tina and Brian did not expel during the self-feeding analysis. Seth expelled six times in Session 12 and once in Session 30. Thus, re-presentation did not affect session length or prevent the caregiver from presenting the next bite on 99% of presented bites for Seth.

Design For the treatment-condition labels, we use the acronyms TF and AF to represent the words target food and avoidance food, respectively. Each label contains two acronyms with accompanying numbers to the left and right of a colon (e.g., 1TF:3TF). The label to the left of the colon is always 1TF, indicating that the caregiver presented the child with one bite of target food to self-feed. The label to the right indicates the number of bites and type of food the caregiver fed to the child if the child did not self-feed. For example, in the 1TF:2AF condition, the caregiver presented the child with one bite of the target food (1TF), and if the child did not self-feed the bite of target food, the caregiver fed the child two bites of the avoidance food (2AF). In Study 1, we evaluated the effectiveness of treatment in an ABCAC design for Tina, an ABCDAD design for Seth, and an ABCDEF design for Brian. The baseline was A, B was 1 TF:1TF, C was 1TF:2TF, D was 1TF:3TF, E was 1TF:4TF, and F was 1TF:5TF. In Study 2, we evaluated the effectiveness of treatment in an ABCDEAE design for Brian. The baseline was A, B was 1TF:1AF, C was 1TF:2AF, D was 1TF:3AF, and E was 1TF:4AF. STUDY 1: BITE-NUMBER MANIPULATION WITH TARGET FOOD Baseline. The caregiver followed the general baseline procedure. Bite-number manipulation with target food. The caregiver followed the general treatment procedure. If the child did not self-feed the bite of target food independently, the caregiver fed the child the prescribed number of bites of the identical target food. For example, in the 1TF:2TF condition, if the child did not accept the bite of chicken independently, the caregiver fed the child two bites of chicken. If the child’s self-fed acceptance did not increase across sessions based on visual inspection of the data, the number of caregiver-fed bites increased from phase to phase until the child began self-feeding

SELF-FEEDING consistently, or we reached a maximum of 1TF:5TF. We did not go beyond 1TF:5TF because the amount of food that the child would have consumed at higher ratios would have been unacceptably large. Mean session length in minutes was 4.3 for baseline, 4.7 for 1TF:1TF, and 3.7 for 1TF:2TF for Tina; 4.3 for baseline, 3.9 for 1TF:1TF, 4.8 for 1TF:2TF, and 4.0 for 1TF:3TF for Seth; and 4.3 for baseline, 4.3 for 1TF:1TF, 4.2 for 1TF:2TF, 4.5 for 1TF:3TF, 5.4 for 1TF:4TF, and 5.9 for 1TF:5TF for Brian. Mean target-bite presentation per minute was 1.2 for baseline, 1.1 for 1TF:1TF, and 1.3 for 1TF:2TF for Tina; 1.9 for baseline, 1.3 for 1TF:1TF, 1.0 for 1TF:2TF, and 1.4 for 1TF:3TF for Seth; and 1.2 for baseline, 1.2 for 1TF:1TF, 1.2 for 1TF:2TF, 1.1 for 1TF:3TF, 0.94 for 1TF:4TF, and 0.84 for 1TF:5TF for Brian. These data suggest that the caregiver was able to present target bites and the child accepted caregiver-fed bites at approximately the same rate across conditions for Tina and Seth. For Brian, presentation of target bites was delayed slightly relative to baseline during the 1TF:4TF and 1TF:5TF conditions. Results and Discussion The results for percentage of self-fed acceptance for Tina (top), Seth (middle), and Brian (bottom) appear in Figure 1. During baseline, Tina infrequently and Seth and Brian never selffed bites. The probability of self-fed acceptance increased when the ratio of self-fed to caregiverfed bites was 1:2 for Tina and 1:3 for Seth. Brian’s self-feeding never increased to clinically acceptable levels. Kerwin et al. (1995) increased volume of food by increasing bite size, the response-effort manipulation, and observed decreases in acceptance. We extended Kerwin et al. in that we increased volume by increasing bite number to decrease one response and increase an alternative response. These results are consistent with basic studies on response effort in that increasing response effort for one behavior shifted responding to an alternative behavior

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(Miller, 1968; Perone & Baron, 1980). In the investigations by Miller and Perone and Baron, at least one of the response choices was arbitrary (e.g., pulling a knob). Those investigations focused on describing the basic effects of alterations of effort on responding, which suggested that effortful responding is aversive. By contrast, the current investigation focused on applying those basic findings to the socially important behavior of self-feeding. Similarly, Patel, Piazza, Layer, Coleman, and Swartzwelder (2005) showed that as texture decreased, packing decreased and vice versa. Patel et al. hypothesized that participants lacked the oral motor skills to manipulate higher textures of food; therefore, decreasing the texture of presented food decreased the response effort associated with eating. Although the probability of self-feeding increased for Tina and Seth as the number of caregiver-fed bites increased, Brian did not self-feed consistently, even when the ratio of self-fed to caregiver-fed bites was 1:5. These results suggest that response-effort manipulations may increase self-feeding in some children with feeding disorders, but not others. STUDY 2: BITE-NUMBER AND FOODTYPE MANIPULATION The purpose of Study 2 was to examine an adjunctive method of increasing self-feeding for Brian. First, we identified a low-preference food (the avoidance food). Next, we increased the ratio of self-fed to caregiver-fed bites as in Study 1, but the caregiver-fed bites were presentations of the avoidance food instead of the target food. Stimulus preference assessment. The purpose of this assessment was to identify an avoidance food to use in treatment. We conducted a pairedstimulus preference assessment based on Fisher et al. (1992) to determine Brian’s relative preference for the 16 foods we used in Study 1. We used the general procedure described above with the following modifications. The caregiver presented two different foods by placing two bowls with one bite of food on a spoon in each bowl on the tray in front of Brian with the

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PERCENTAGE OF BITES WITH SELF-FED ACCEPTANCE

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Figure 1. Percentage of bites with self-fed acceptance for Tina (top), Seth (middle), and Brian (bottom) during Study 1.

prompt to “pick one.” The caregiver presented each food with every other food and selected the order of pairings randomly. If Brian chose a food, the caregiver provided brief praise, removed the

bowl of the nonchosen food, presented the chosen food by touching the spoon to Brian’s lips for 30 s, and deposited the bite if Brian opened his mouth during the 30-s interval. The caregiver

SELF-FEEDING did not re-present expelled bites. If Brian did not choose or accept a bite during the 30-s interval, the caregiver removed the bowls and presented the next pair of foods. The results of the preference assessment identified scrambled eggs as the least preferred food for Brian. Thereafter, the caregiver presented scrambled eggs only in the avoidance procedure and did not present scrambled eggs in the rotation of target foods in baseline or treatment. Baseline. The procedure was identical to that of Study 1, except the caregiver did not present scrambled eggs. Bite-number and food-type manipulation. The procedure was similar to that of Study 1, except when Brian did not self-feed the bite, the caregiver fed him the prescribed number of bites of avoidance food. To illustrate, in the 1TF:3AF condition, the caregiver presented a bite of mashed potatoes. If Brian did not self-feed the bite of mashed potatoes, the caregiver removed the bowl of mashed potatoes and fed him three bites of scrambled eggs. Mean session length in minutes across phases was 4.2 for baseline, 5.1 for 1TF:1AF, 5.3 for 1TF:2AF, 5.3 for 1TF:3AF, and 4.9 for 1TF:4AF. Mean target-bite presentation per minute was 1.2 in baseline, 0.99 for 1TF:1AF, 0.94 for 1TF:2AF, 0.96 for 1TF:3AF, and 1.1 for 1TF:4AF, suggesting that the caregiver was able to present target bites and Brian accepted caregiver-fed bites at approximately the same rate across conditions. Results and Discussion The top panel of Figure 2 shows the percentage of consumption (solid bars) and avoidance (dotted bars) during the preference assessment, and the bottom panel shows the percentage of self-fed acceptance during the self-feeding analysis. During the preference assessment, Brian did not consume four foods (chicken, scrambled eggs, creamed corn, baked potato), which suggested that these foods were less preferred than the foods he consumed more frequently during the assessment. We examined the avoidance data to further discriminate Brian’s prefer-

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ence for the four less preferred foods. Of the four foods that Brian never consumed, he engaged in the highest levels of avoidance behavior (20% of trials) with the scrambled eggs; therefore, we chose scrambled eggs as the avoidance food. During baseline of the self-feeding analysis, Brian infrequently self-fed target bites. He engaged in steadily increasing levels of self-fed acceptance when the ratio of self-fed target bites to caregiver-fed avoidance bites was 1:4. When effort manipulations alone were not effective for Brian in Study 1, we evaluated his relative preferences for the target foods and identified his least preferred food. An alternative method for identifying avoidance foods would be to use caregiver report regarding foods the child had avoided in the past or to use foods that are consumed less often by the general population. Consistent with Vaz et al. (2011), we conceptualized presentation of the least preferred food as a quality manipulation. When we altered effort and quality of caregiver-fed bites, responding shifted to self-feeding when being fed was associated with presentation of four bites of the avoidance food. These data replicate other studies that show that manipulations of the parameters associated with responding can be an effective method for changing behavior. For example, Athens and Vollmer (2010) evaluated the effects of alterations of duration of, quality of, and delay to reinforcement, and a combination of these parameters during differential-reinforcement-of-alternativebehavior schedules. Although the various manipulations in isolation produced some changes in behavior, the greatest changes occurred when multiple manipulations occurred simultaneously. Similarly, the greatest and most consistent changes in behavior for Brian occurred when the caregiver manipulated both the response effort and the quality of food associated with being fed. GENERAL DISCUSSION These results are important for a number of reasons. First, the results suggest that a history of a

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PERCENTAGE OF TRIALS

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Figure 2. Percentage of trials with consumption (solid bars) and avoidance (dotted bars) by food during the stimulus preference assessment (top) and percentage of bites with self-fed acceptance (bottom) for Brian in Study 2.

feeding disorder may be associated with refusal to self-feed in an age-typical manner, at least for the participants in the current investigation. The children were at or beyond the age (19 to 24 months) at which self-feeding is expected to emerge, yet none exhibited consistent selffeeding behavior. At home, they rarely or never self-fed by caregiver report, and in the clinic, selffeeding was inconsistent. The failure to self-feed did not appear to be due to motor limitations, because we had observed the children self-feed in the past and they were able to self-feed without assistance during treatment. The behavior of the

children in this investigation was similar to our clinical experience that many children with severe feeding disorders do not exhibit age-typical selffeeding without intervention. The data from the current study suggest that this refusal may be a function of a motivational deficit. The results of the current investigation extend those of Kerwin et al. (1995) and Vaz et al. (2011). As Kerwin et al. noted, a history of medical problems, oral-motor problems, or both, and escape from bite presentations may bias the responding of children with feeding problems in favor of refusal. The data from the current

SELF-FEEDING investigation are consistent with Kerwin et al. in that participants more often refused to eat when given the choice between escape from eating and self-feeding in baseline. The children also chose to be fed either more often (Seth and Brian) or at least some of the time (Tina) when given the choice between being fed and self-feeding the identical bite of food in the 1TF:1TF condition. Recall that Vaz et al. used a combination of effort and quality manipulations to increase selffeeding. However, it was not clear whether both were necessary. The results from the current investigation suggest that different manipulations may be necessary to alter the behavior of different children. Nevertheless, these data provide a model for how contingencies may be manipulated to increase self-feeding. The model we used was one in which the first manipulation was to increase the response effort associated with being fed via systematic increases in the ratio of caregiver-fed to self-fed bites of the same food. If the response-effort manipulation was ineffective, we then manipulated both the effort and quality of food associated with being fed. Although we used the model of response effort followed by effort and quality manipulations, other sequences or types of manipulations could be the focus of future research. One unanswered question is why different manipulations were effective for different children. Recall that of the three children, we used the largest bolus size and a higher texture of food with Brian; thus, eating for him may have been even more effortful than for Tina and Seth. That may be one reason Brian required manipulations of response effort and food quality to increase self-feeding, and this could be a topic for future investigations. An alternative explanation is that Brian had received the least amount of feeding therapy of the three participants before the start of this study. Interestingly, the number and type of manipulations necessary to increase selffeeding were inversely correlated with the duration of feeding therapy. Of the three children, Tina began self-feeding with the fewest

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manipulations, and she had participated in feeding therapy for the longest time. Brian began self-feeding with the most manipulations, and he had participated in feeding therapy for the shortest time. However, it is not clear whether length of feeding therapy had any impact on the self-feeding manipulation. These results are also important because there have been surprisingly few investigations on increasing self-feeding in children with underlying feeding disorders. The majority of investigations on self-feeding have involved participants with disabilities who required training to master the specific skills associated with self-feeding (Collins, Gast, Wolery, Holcombe, & Leatherby, 1991; Leibowitz & Holcer, 1974; Luiselli, 1991, 1993; Piazza, Anderson, & Fisher, 1993; Richman, Sonderby, & Kahn, 1980; Sisson & Dixon, 1986; Stimbert, Minor, & McCoy, 1977; Thompson, 1977). Self-feeding is a behavior that is important for the child’s socialization (i.e., for the child to be similar to same-aged peers) and is valued by caregivers (Schulze, Harwood, & Schoelmerich, 2001). If refusal to self-feed is, in fact, a chronic problem for children with feeding problems, then investigations like the current study and those of Luiselli (2000) and Vaz et al. (2011) are important in providing clinicians with the necessary tools to address the problem. The data from the current investigation also are important because few studies have been conducted using negative reinforcement and both response-effort and quality manipulations to increase a desirable behavior. Manipulations in the majority of studies have focused on increasing response effort of an inappropriate behavior to decrease that inappropriate behavior (e.g., selfinjury; Hanley, Piazza, Keeney, Blakeley-Smith, & Worsdell, 1998; Van Houten, 1993), to shift responding from an inappropriate to a more desirable behavior in the context of concurrent reinforcement schedules for both behaviors (e.g., self-injury and toy play; Shore, Iwata, DeLeon, Kahng, & Smith, 1997), or to test the efficacy of different stimuli as reinforcement during

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progressive-ratio schedules of reinforcement (e.g., Glover, Roane, Kadey, & Grow, 2008). Some limitations of the study are that we did not evaluate a positive reinforcement procedure for self-feeding before our manipulations. Although a number of studies have shown that reinforcement for acceptance and swallowing may be an effective treatment for food refusal (e.g., Stark, Bowen, Tyc, Evans, & Passero, 1990; Stark et al., 1993; Turner, Sanders, & Wall, 1994), more recent studies have demonstrated that putative escape extinction may be a necessary component of treatment for some children (e.g., Bachmeyer et al., 2009; LaRue et al., 2011; Piazza, Patel, Gulotta, Sevin, & Layer, 2003; Reed et al., 2004). In fact, all of the children in the current investigation required an escape extinction component in the initial treatment of their feeding problem that was conducted before the current investigation. Therefore, we hypothesized that these children were not likely to respond to reinforcement procedures for selffeeding. As Kerwin et al. (1995) noted, positive reinforcement may be a “luxury” that some children with feeding disorders are willing to forgo if the cost of that luxury is consumption. Said another way, many children with feeding problems would choose not to eat rather than eat and access highly preferred stimuli, and it often is difficult to identify preferred stimuli that compete with escape from eating (Piazza et al., 2003). Nevertheless, this hypothesis is speculative, and future investigators might explore the use of positive reinforcement or a combination of positive reinforcement, response-effort, and quality manipulations to increase self-feeding. A second limitation is that the data were variable during many of the phases. The caregiver presented four target foods in each session, and it is possible that this variability was due to the child’s relative preferences for individual target foods. However, we did not conduct a preference assessment of foods for children in Study 1, and we did not examine responding to individual foods. This could be a topic for future investigations.

Another limitation is that the initial treatments implemented before the current study to establish consumption occurred in the context of a caregiver feeding the child. It is possible that this history of being fed during initial treatment biased the children toward being fed and reduced the probability that they would self-feed. We first treated the children in the context of being fed because we hypothesized that being fed was less effortful than self-feeding and that reducing the effort of eating was important for establishing consumption. It is not clear whether the method by which initial acceptance is established in children with feeding disorders affects the subsequent probability of self-feeding, but this could be a topic to explore in future research. In conclusion, we evaluated a method to increase self-feeding by three children with a history of food refusal. We showed that these children often preferred to be fed when given a choice between being fed by a caregiver or selffeeding. We then manipulated the response effort or response effort and quality of food fed by the caregiver. The results showed that altering the contingencies associated with being fed increased the probability of self-feeding. Even though the specific manipulations that produced self-feeding were unique to each child, this study provides a general model for manipulating concurrent contingencies to increase self-feeding.

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