The Analysis of Verbal Behavior 1985, 3, 11-18

Teaching Verbal Behavior to PigeonsMark L. Sundberg

California State University, StanislausPigeons were taught simple analogs of verbal behavior by replicating and extending the procedurespresented by Michael, Whitley, and Hesse (1983). A student lab, connected to a course on theexperimental analysis of behavior, was used to teach both the students and the pigeons newbehavioral repertoires. Most of the 18 birds learned a simple stimulus-selection-based tact, as wellas 2-3 topography-based tacts. Several pigeons learned to mand for reinforcers, and a few acquiredsome simple intraverbal responses. The student's learned the basic features of Skinner's analysisof verbal behavior, as well as several laboratory skills. Further work in this area is encourageddue to its potential contributions to the experimental analysis of verbal behavior, and to teachinglanguage to the developmentally disabled, and other speech and language impaired individuals.

Skinner's (1957) analysis of verbal behaviorhas generated a great deal of discussion, butvery little empirical research (McPherson,Bonem, Green, & Osborne, 1984). Skinner(1978) believes his work has been slow inaffecting the culture because those whomainly study language (e.g., linguists andpsycholinguists) lack a technical understan-ding of an operant analysis. Also, Skinner(1978) points out that these language scholarshave traditionally emphasized cognitive pro-cesses as causal factors and "are primarilyconcerned with the listener-with whatwords mean to those who hear them, andwith what kinds of sentences are judgedgrammatical or ungrammatical" (p. 122).Such orientations have prevented research-ers from isolating and studying the appro-priate independent and dependent variablesinvolved in verbal behavior. Thus, it is nosurprise that empirical support for anenvironmental analysis of language has notcome from those already studying language.Michael (1984) gives several possible expla-

nations why researchers who are notcognitive in their orientation, and have thetechnical background in operant analyses,have neglected Verbal Behavior (Skinner,1957). Perhaps most relevant to the currentpaper is the point that:

Basic researchers whose training prepared themto appreciate Skinner's analysis already had ahighly productive research methodology, involv-ing response rate as the dependent variable andautomated data collection.. ..Operant re-searchers in the late fifties and early sixties werestrongly committed to behaviorism as a databased science, and less interested-or in somecases even embarrassed by-Skinner's specu-lative extensions to human affairs... .the applied

behavior analysis developing in the same periodalso had an emphasis on data, as the only validbasis for procedure and policy, and from this pro-spective Verbal Behavior did not seem particularlyuseful (p. 369).

A review of the contents of the Journal of theExperimental Analysis ofBehavior and the Jour-nal ofApplied Behavior Analysis will show thatreseachers, for the most part, continue toneglect the topic of verbal behavior. The bookVerbal Behavior plays almost no role in con-trolling research activity in the behavioralfield, yet the topic of language is perhaps thesingle most important area in human affairsand psychology in general. In 1978 Skinnerwrote: "Verbal Behavior...will, I believe,prove to be my most important work" (p.122).Skinner's book Verbal Behavior (1957) con-

tains a radical behavioral analysis of the topicgenerally referred to as 'language." Skinner'smain thesis is that language is learnedbehavior controlled by antecedents, conse-quences, and establishing operations. Theanalysis of these environmental variablesreveals several different types of controlwhich Skinner identifies as echoic, mand,tact, intraverbal, textual, and transcriptive(he also presents the audience as a source ofcontrol). Skinner proposes that theseelementary verbal relationships are separatecontingencies of reinforcement and can besubjected to an experimental analysis ofbehavior (Skinner, 1969, p. 25), and in fact,have several advantages as a topic of study(Skinner, 1957, p. 5).However, verbal behavior is an extremely

complex area. Michael (1984) points this outby listing some of the topics found among

11

12 MARK L. SUNDBERG

the first twenty entries in the index of VerbalBehavior (abstraction, abulia, acrostics, ag-glutinated languages, agnosia, agram-matism, alexia, allegory, alliteration, allu-sion, amanuensis, and ambiguity). The"main difficulty is not with the 'behavioral-izing,' but rather with what is beingbehavioralized" (Michael, 1984, p. 369). Thebehavioral researcher who works primarilywith nonhumans does not usually come incontact with these complexities, or othertopics relevant to verbal behavior such asrule-governed behavior, thinking, and com-plex social behavior. Also, nonhumans havenot developed the elaborate collection of con-ditioned reinforcers and conditionedestablishing operations which may controlhuman verbal behavior. Recently, however,basic human operant research is increasingand researchers are starting to address someof these complexities (e.g., Hake, 1982;Buskist, 1982), and several studies on thebasic elementary operants have beenpublished (e.g., Boe & Winokur, 1978; Braam& Poling, 1983; Lamarre & Holland, 1985;Lee, 1981; Lee & Pegler, 1982; Savage-Rumbaugh, 1984).The present study is an attempt to develop

some simple analogs of verbal behavior inpigeons. The study is a replication and exten-sion of a project started by Jack Michael andhis students at Western Michigan Universi-ty (Michael, Whitley, & Hesse, 1983). Theirprimary research emphasis was to developrepertoires corresponding to Skinner'selementary operants as presented in VerbalBehavior. Michael et al. (1983) were successfulin teaching several forms of verbal behaviorby using motor responses (not unlike thoseof the American Sign Language) such as cir-cle turning, head bobbing, and toe peckingas response forms. These responses canbecome linguistic according to Skinner (1957,p. 14) because the form of the response (whatis said, signed, written, etc.) is not a defin-ing feature of verbal behavior. The criticalfeature is that some consistent form ofbehavior be under the functional control ofenvironmental variables.Skinner (1974, pp. 89-90) points out that a

unique feature of most verbal behavior is thatthe response can occur on almost any occa-sion and does not require environmentalsupport. The forms of behavior for most ofthe current study were free from en-

vironmental support, that is, the responseforms were exclusively part of the organism'smusculature and not dependent on physicalfeatures of the environment. Michael (1985)and his colleagues (Michael et al., 1983)distinguish between two types of verbalbehavior based on the response topographyand environmental support necessary for theemission of the response. He has termedthese stimulus-selection-based verbal behavior(dependent upon environmental support)and topography-based verbal behavior (freefrom support). Michael et al. (1983) taughttheir pigeons three forms of behavior;stimulus-based tacts, topography-basedtacts, and mand compliance (receptivebehavior). The current study is a replicationof their procedures for developing astimulus-selection-based tact and atopography-based tact. Then, transfer ofstimulus control procedures were used tobring the topography-based tacts under thecontrol of establishing operations (mands),and verbal stimuli (intraverbals).

METHOD

SubjectsEighteen naive Humboldt pigeons, main-

tained at 85%-95% of their free-feedingweights, served as subjects. All birds weretamed by hand feeding in order to establishthe hand as a form of conditioned rein-forcement.

Setting and Sessions

Training was conducted in an open en-vironment (a 5' x 7' study carrel) withoutrestraining the pigeons or clipping theirwings. Sessions occurred five times a weekwith a mean length of 30 minutes, and con-tained approximately 50 reinforced trials.

Trainers

The main body of experimenters consistedof 34 students from Psychology 4720 (TheExperimental Analysis of Behavior) atCalifornia State University, Stanislaus. Thiswas the first experimental laboratory experi-ence for all students. Lab partners wereselected, and each pair of students wasassigned complete care and responsibility forone bird (two of the teams had threemembers). The instructor (the author) and

TEACHING VERBAL BEHAVIOR TO PIGEONS 13

his assistant also conducted the experiment,each with one bird.

Apparatus and materials

There were only a few materials used inthe experiment. An experimental chamberwas not necessary because the pigeonstypically worked in an open area while stan-ding on blocks of wood on a desk top (or onthe floor, or on the experimenter's knee).Stimuli were chosen by the experimentersand they typically consisted of geometricaldesigns, objects (e.g., cup, jar, lid, glasses),or written words. Mixed grain was used asreinforcement and it was delivered by hand.Grain delivery was preceded (within one se-cond) by a whistle or some other stimulus(e.g., click, "tsk-tsk") agreed upon by bothpartners.

Measurement, design, and reliabilityThe primary emphasis of the laboratory ex-

ercise was to develop the verbal repertoires(of the birds and students) rather than con-duct a formal research project. Hence, themeasurement system and design were allow-ed to evolve over the course of the experi-ment. It was the general consensus that anemphasis on methodology and designwould delay the development of the verbalrepertoires, especially since most studentswere naive to measurement techniques, andall the dependent and independent variablescould not be identified at the out-set of theexperiment. However, it was clear that theresearch project would teach us about apotential methodology for future research.Data were collected in a number of differentways including the latency, frequency, andtopographical characteristics of theresponses. Reliability of the repertoires wasconducted by observations of the birds' per-formance by the instructor and the courseassistant. This method of reliability is similarto what Skinner (1957) calls "confirmation"'(p. 425).Experimental procedures

Preliminary training procedures. The ex-perimenters tamed their birds by using milddeprivation (85%-95% body weight) andhand feeding. After the bird would calmlyeat out of one hand while being restrainedby the other, the experimenters took their

hungry bird to a study carrel and let himloose while holding out their hand contain-ing grain. When the bird approached and atehe was allowed approximately 5 seconds ofgrain. All experimenters recorded the latencybetween opening their hand and the firsteating response of each trial (magazinetraining).

Stimulus-selection-based tact training

A simple stimulus-selection-based tact wastrained by using a basic shaping procedure.The birds were taught to peck a red dotpresented in various locations around theroom, and to discriminate it from an array ofsimilar stimuli (e.g., blue dots, squares).Once the birds could respond correctly, onat least 90% of the trials, they began the nextphase of training.

Topography-based tact trainingThe preliminary procedures and stimulus-

selection training took approximately four tosix weeks. Following the acquisition of peck-ing the red dot and discrimination training,each pair of experimenters picked a newnonverbal stimulus and trained the bird, us-ing standard shaping techniques, to emit aresponse that was free from any environ-mental support (e.g., turning in a clockwisecircle, pecking the third right toe). Theresponse was brought under the exclusivecontrol of the specific nonverbal stimulus, byconducting unreinforced trials in thepresence of different stimuli.

Typically, experimenters sat in studentdesk-chairs with the pigeon perched upon ablock of wood. The stimuli were placed onsmall blocks (5 cm in diameter) and theexperimenter would raise the block fromunder the desk and present it approximate-ly 5 inches in front of the pigeones eyes. (Theblock also contained the red dot on one side,and stimulus-selection trials were inter-spersed with the tact training.) Any approx-imation to the target response was immedi-ately reinforced with a whistle (or whateverform of conditioned reinforcement had beenestablished) and a few seconds of graindelivered by raising the other hand up fromunder the desk. Both hands were thenlowered under the desk and a five secondinter-trial interval occurred.Experimenters repeated the procedure

14 MARK L. SUNDBERG

with a second stimulus and a secondresponse topography. These stimuli wereplaced on a different side of the same blockalong with the red dot, and the firsttopography-based stimulus configuration.Trials on the new verbal relation were in-terspersed with the previously establishedrepertoires. Some experimenters went on toestablish a third topography-based tact.

Transfer of stimulus controlIt was necessary to teach the bird to tact

some physical object so he could later mandfor that object. A baby food jar and the lid tothat jar served as the first two stimuli formost experimenters. One stimulus wastaped to the jar and the other was taped tothe lid. The birds were presented trials in thesame manner as above except the stimuliwere on the objects instead of the blocks.After a few trials, the symbols were remov-ed from the objects and training was con-ducted with the objects alone as stimuli.

Transfer to establishing operationsMichael (1982) defines establishing opera-

tions (EO's) as "any change in the environ-ment which alters the effectiveness of someobject or event as reinforcement andsimultaneously alters the momentary fre-quency of the behavior that has been follow-ed by that reinforcement" (pp. 150-151).Michael identifies two types of EO's; uncon-ditioned establishing operations (UEO) andconditioned establishing operations (CEO).The distinction is in terms of the learninghistory required for CEO's. The objective inthis phase of the training was to bring aspecific response under the control of aspecific CEO.The grain was placed in the jar and the lid

was placed on the jar. The jar was placedunder the desk and a delay procedure (Halle,Baer, & Spradlin, 1981) was used. The birdswould typically emit several behaviors, andupon emission of the appropriate responsefor jar the conditioned reinforcer was givenalong with raising the jar to the top of thedesk. The experimenter then waited againuntil the appropriate response for "lid-off"occurred and then delivered the condition-ed reinforcer (e.g., whistle), removed the lidand allowed the bird to eat.

An additional type of mand training con-sisted of teaching the bird to ask for a specificjar which contained the grain. The ex-perimenter placed the geometric shapes ondifferent jars, and only one contained food.If the bird emitted the correct "selection"response he was allowed to eat some grainfrom that jar.

Transfer of stimulus control to verbal stimuli

Once the birds could emit the sameresponse topography under two separatetypes of control (nonverbal stimuli andestablishing operations) a few experimentersprogressed on to transfer control to writtenstimuli. The procedure consisted of eithersuperimposing the symbol on the writtenword, or using a delay procedure and rein-forcing the response under the presence ofthe written word. This verbal relation wouldbe analogous to the deaf signer who "reads"English by emitting signs controlled by writ-ten words. Hence, the relation is an intraver-bal because of the lack of point-to-point cor-respondence between the stimulus and theresponse.

RESULTS

Preliminary training

During the first several sessions in theopen environment the first latency to theeating response was over one hour for manybirds. For most birds the latency wouldslowly decrease during the session to under10 seconds, but then increase again at thebeginning of the next session. It took mostexperimenters approximately ten sessions tocompletely desensitize their birds (and insome cases, themselves) as measured by aconsistent latency of less than three seconds.

Stimulus-selection-based tactingMost experimenters were successful in

teaching their bird to peck the red dot inabout two sessions. Discrimination trainingand selection from an array of stimuli tookan additional two to five sessions for mostexperimenters.

Topography-based tacting

All the birds acquired the first topography-based tact in one to three sessions (see Table

TEACHING VERBAL BEHAVIOR TO PIGEONS 15

Table 1.Topography-Based Tacts

Response 1 Response 2

Bird # Stimulus Response Sessions Stimulus Response Sessions

31 Spiral Turn Right 3 Grid Peck 3rd 3Circle Circle Right Toe

33 Blue Star Turn Left 2 Green Foot 7Circle Triangle Stomp

34 Green Tum Left 1 Jar CooTriangle Circle Sound 8

35 Checked Head Bob 3 Blue Star Peck 2nd 14Square Right Toe

36 Checked Head Bob 3 Tan Cube Tum Right 1Square Circle

37 Spiral Tum Right 1Circle Circle

39 Blue Turn Right 1 Brown Left Wing 7Triangle Circle Spiral Peck

40 One Inch Wing Flap 1 Spiral Tum Right 1V Circle Circle

41 Blue Tum Right 1 Cup Peck 2nd 9Triangle Circle Right Toe

42 Purple Turn Right 1 Grid Peck Left 4X Circle Wing

43 Blue Star Tum Left 1Circle

44 Blue Dot Turn Left 1 Green Tum Left 1Circle Triangle Then Right

45 Spiral Tum Left 2Circle Circle

46 Spiral Tum Left 3 Black Peck Right 1Circle Circle Cross Wing

47 Blue Tum Right 3 Grid Wing Flap 1Triangle Circle

48 Blue Turn Right 2 Grid Peck Right 3Star Circle Toe

49 Blue Tum Right 1 Green Peck Right 3Triangle Circle Triangle Toe

50 Sunglasses Tum Right 3Circle

1). The first correct target response (e.g., tur-ning a circle) often occurred within the firstten minutes of the first session. The red dotwas interspersed with the new topography-

based tact stimulus and aU birds would con-sistently emit the peck to the red dot whenit was presented demonstrating two simple,but separate, repertoires. When presented

16 MARK L. SUNDBERG

with an irrelevant stimulus the birds typical-ly would not respond.Eight birds acquired a second topography-

based tact in one to three sessions, six birdsacquired it between four and fourteen ses-sions, and four birds failed to acquire a se-cond tact. Several of the experimenters haddifficulty with teaching their bird not to emitthe first topography under the control of thesecond stimulus (a common problem in theearly phases of teaching sign language to thenon-vocal developmentally disabled indi-vidual). The more skillful shapers were ableto successfully extinguish inappropriateresponses and reinforce small approxima-tions to correct responses and teach the newrepertoire quickly. Three teams were suc-cessful in teaching a third topography-basedtact.

Transfer of stimulus control

Transfer from a geometric stimulus to anobject occurred in a surprisingly short periodof time, often in only a few trials.

Transfer to establishing operationsTransfer to the conditioned establishing

operation usually occurred in a few trials andthe two-component response became strongin about two sessions. Thirteen birds suc-cessfully acquired a two-component mandwhich usually consisted of the bird "asking"for an absent jar, and then "asking" toremove the lid from the jar (some experi-menters had the bird ask for a special lightto be turned on, or used a cup instead of ajar). A test for the accuracy of the source ofcontrol for the mands "jar," and "lid off,"demonstrated that in the presence of the jar,with the lid on, the response "jar" would notoccur, rather "lid off" would occur. If the jarwas presented with the lid off no responseoccurred and the bird would begin eating thegrain. If there was no grain in the jar the birdwould usually pace around and preen. Thus,like Michael's (1982, p. 152-153) electricianexample, the presence of the covered jar (theslotted screw) altered the value of removingthe lid (the screwdriver), and evoked thebehavior of asking for the lid to be removed(asking for the screwdriver). When the lidwas removed (when the electrician receivedthe screwdriver) the mand ceased. If the lidwas off, but present (if the screwdriver was

readily available) the mand did not occur.The ultimate consequence was grain for thepigeon, but the experiment was not unliketeaching a child to ask for spoon in order toeat his ice cream.A few birds were taught the "mand selec-

tion" repertoire and acquired it in one ses-sion. The birds would readily "ask" theexperimenter for a jar which contained foodby emitting the "name" of the jar. This pro-cedure was like asking a child to select froma number of different items one which func-tioned as reinforcement at that moment.

Transfer to verbal stimuli

Seven students continued the experimentthe following semester as an independentstudy. They replicated many of the aboveprocedures and worked on the improvementof the data collection system. Three birds ac-quired a simple intraverbal repertoire con-sisting of emitting the same response (whichhad been previously acquired as a mand andtact) under the control of written stimuli(e.g., "LID," "JAR"). These birds all acquiredat least six separate verbal relations(McDoungh & Sundberg, 1984; Winfrey,1984). The birds could consistently emit twoappropriate responses under the control ofnonverbal stimuli (tact), conditionedestablishing operations (mand), and writtenwords (intraverbal). The transfer of stimuluscontrol was more difficult than with theother repertoires, but still occurred betweenthree and eight sessions. The delay pro-cedure was much more successful than thefading procedure. And all the verbal reper-toires became weak if training was disruptedfor more than a week.

DISCUSSION

The experimenters and pigeons acquireda number of new behaviors during thecourse of the experiment. Perhaps most sur-prising was the speed in which the pigeonsacquired the verbal responses. Many of theexperimenters were able to teach their birdsa specific topography in a matter of minutes.Simultaneously, that response came underthe control of a specific nonverbal stimulus.Once stimulus control was established, thetransfer of stimulus control to a different var-iable occurred very quickly by using prompt-ing and fading, and delay procedures.

TEACHING VERBAL BEHAVIOR TO PIGEONS 17

It appears that the essential features ofteaching pigeons topography-based verbalbehavior involve bringing a motor response(which is free from environmental support)under some type of stimulus control, andthen transferring that control to the variablesinvolved in verbal behavior. Imitative controlis typically used for teaching sign languageto the developmentally disabled, and oncecontrol is established, training is given totransfer control to other nonverbal and ver-bal antecedents and establishing operations(Sundberg, 1980). Transfer to those sourcesof control occurred so rapidly with thedevelopmentally disabled that the authoridentified the procedure as the "the quicktransfer procedure." However, the number oftrials required to transfer stimulus controlwith pigeons was less than those required formany nonvocal developmentally disabledpersons.The students became quite skillful in

observing behavior, shaping, prompting,fading, and delivering consequences. Theirverbal repertoires also showed some majorchanges. The terms mand, tact, and intra-verbal became part of their analytical reper-toire and classroom analyses ofhuman situa-tions showed great improvement. Thestudents were very proud of their birds andtook every opportunity to show them off.Perhaps the main result of the lab was thatthe students had become very confident inthe principles ofbehavior and the techniquesof behavioral engineering.Some of the experimenters had difficulty

teaching the birds the second tact and morecomplicated behavior. The training requiredcareful shaping procedures with immediatedifferential reinforcement for very smallimprovements and mistakes often took along time to correct. Also, some of the birdsemitted an increased amount of aggressivebehavior as the repertoires become morecomplicated (not unlike many development-ally disabled individuals). This was probablydue to their poor conditioning history andschedule strain.The current study could be improved in a

number of ways. Perhaps most importantwould be the use of a more refined data col-lection system and experimental design. Dueto the exploratory and instructional nature ofthe lab a number of standard procedures forensuring experimental rigor were not

employed. However, a useful data collectionsystem was developed during the twosemesters. A modified version of the systemused for the developmentally disabled wasused (Sundberg, 1980). The essentialfeatures consist of a coding system for scor-ing all the antecedents and consequences ofeach verbal episode, along with the responselatency and topography. A second experi-menter was necessary to collect the data, buta running account of the verbal episodesbetween the experimenter and the pigeonwas useful. Attempts at collecting latencydata were also promising. Ultimately, a com-puter could be used to record all these data.Such a system could help refine the trainingprocedures and further promote thedevelopment of the experimental analysis ofverbal behavior.The experiments conducted in this lab pro-

duced only small verbal repertoires in thepigeons, but the potential for more complexverbal repertoires seems clear. Furtherresearch could be conducted in virtually allaspects of verbal behavior given the refine-ment and extensions of these basic pro-cedures and repertoires. This researchshould improve our understanding of verbalbehavior, as well as increase our efficiency inteaching language to the developmentallydisabled, and other speech and impairedindividuals.

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