Interpersonal referential communication experimentswith a small computer*

LOUIS van ROOIJEN and FRANKM. GOODEtThe University ofMichigan, Ann Arbor, Michigan 48104

A LINC-B computer is used with a Tektronix 611CRT for presenting verbal information, and a slideprojector for displaying facial photographs in studies ofinterpersonal referential communication.

In the Mathematical Psychology Laboratory at theUniversity of Michigan, an integrated set of programs,written in LAP-6 for the LINC-8 computer, has beendeveloped for the on-line control of experimentsconcerned with information processing in interpersonalreferential communication.

This kind of communication is defined ascommunication between a communicator (speaker,writer, actor) and a receiver (listener, reader, viewer)about a referent. The referent is restricted to anidentifiable stimulus in their immediate environment. Aprobabilistic theory for referential communication wasproposed by Rosenberg and Cohen (1966).

Data are now being collected in two experimentsusing the referential communication paradigm. A thirdstudy is planned to follow immediately when the resultsof these experiments have been analyzed.

In the first experiment, the S is the receiver of a seriesof written messages, which were previously generated bydiffere nt communicators describing as referentsphotographs of an actor who facially expresses variousemotions. These photographs were taken from theFreis-Wittmann series of emotional expressions (Hulin&Katz, 1935). The major purpose of this experiment is tostudy the effects of certain characteristics of thecommunicator's message (description of the facialexpression) on the individual receiver's accuracy ofreferent identification and his processing time. Thesemessage characteristics are based on judgmentspreviously collected from a norm population of collegestudents (Manis & van Rooijen, 1973; van Rooijen &Manis, 1972). Of special interest here are: thedescription's ambiguity (the number of different

SlideProjector &Shutter

Tektronix611 StorageUnit

LINC-8

Computer Subject I 5Response Units:-desaription &faces buttons

-choiae buttons-potentiometerknob

Magnetic Tape:-presentationtables

-referentialdescriptions

-responsedata

for off-lin~ ~~--1 Paper Tape Teletypestatistiaal analysis Punch Printer

Fig. 1. Schematic representation of the computer-controlled experimental environment.

*This work was partially supported by Public Health ServiceGrant GMo01231-09 to The University of Michigan.

tWe want to thank Cyrus Ulberg for his assistance with thephotography .

Behav. Res. Meth. & Instru., 1973, Vol. 5 (2) 157

S pushes red b~tton

foLlcMir.g 4 pages

console input by E

Display ready signal

Display a page of experimental instructions

S ushea ~ed button

Read control set-up

and displayed on the 611 CRT as if the description werebeing written from left to right at a comfortable readingspeed. After he has finished reading the description. theS pushes a button, at which time the computer turns offthe description display and opens a high-speed shutier(Uniblitz., Vincent Associates). This allows an array ofeight photographs to be projected on a wall screen (Witha Kodak Carousel slide projector). Figure 2 shows theexperimental setup in the first study. To simplify theillustration. the photograph shows both the descriptionand the faces, although they do not actually appeartogether in the experiment.

The S then pushes one of eight buttons. to select thefacial expression picture which he believes was thereferent photo described in the message. At the sametime, the computer turns off (he projection of the eightfaces on the screen. His reading time, his choice, and hisdecision time are recorded. During the intertrial interval.the computer cycles the projector to the next slide ofeight photographs, and presents a ready signal on the

Fig. 2. The S's stimulus displays and response units inStudy 1.

plausible referents), validity (the probability of correctreferent identification), and redundancy (the extent towhich different .referents are mote or less likely to bechosen).

Figure I shows a schematic representation of thecomputer-controlled environment for all three studies.

In the first study, the E selects one of six stimulipresentation sequences for a given S and feeds thiscontrol parameter via. theconsole into the LINC-8. Theprogram then reads the particular stimuli presentationsequence table into core from magnetic tape. Four pagesof experimental instructions are presented to the S on aTektronix 611 storage unit (611 CRT), using a softwaredisplay package by Coode.! (The LINC-8 CRT is notused in these experiments.) When the S clearlyunderstands the instructions, the actual experimentalsession begins. On each triaL one description (previouslygenerated by a communicator about a facial expressionphoto) is selected by the program from magnetic tape,

Display description

Description off; show faces

S pushes cr~ice buttonts rJf 8)

Faces off; record response variables

after 4 secoruia

Display Thank You

Store· data on magnetic tape

Punch data on ~aper tape

Fig. 3. Transition diagram of the experimental sequence inStudy 1.

158 Behav. Res. Meth. & Instru., 1973, Vol. 5 (2)

Fig. 4. The S's stimulus displays and response units inStudy 2.

611 CRT. after which the S can initiate a new trial bypressing a start button. At the end of the experimentalsession, the computer saves the record of stimuli andresponse data on magnetic tape. A copy of this record isprinted on the Teletype printer. if desired. A high-speedpaper-tape punch is used to transmit the S's stimulus andresponse data for off-line statistical analysis on theUniversity of Michigan's central computer. Figure 3shows a transition diagram of the experimental sequencefor the first study.

The second experiment analyzes the effects of varyingfrequencies and duration of referent exposure onsubjective judgments about selected attributes of thereferent. This experiment is run immediately followingthe first one. using the same S. The Frois-Wittrnannfacial expression pictures are now projected one at atime on the wall screen. One set of these photographshas been exposed previously in the first experiment with

Behav. Res. Meth, & Instru .. 1973. Vol. 5 (2)

different frequencies and at different durations. Theother set consists of unexposed facial expressions, whichare matched with the first set on two major evaluativedimensions. pleasantness-unpleasantness andattention-rejection. as determined by scale valuesobtained by Schlosberg (1952). At the beginning of tillsexperiment. the E inputs. via the console, the controlparameter for one of two slide projection sequences,which the program reads into core from magnetic tape.

The S makes three series of ratings of each referentpicture. First. he evaluates how much he likes theexpression in the picture; then, he judges the amount ofattention-rejection conveyed by the expression; andfinally. he judges how pleasant the man in the picturefeels. Each series is preceded by a display of instructionson the 611 CRT, explaining the use of the rating-scaleprocedure and the particular attribute to be judged. TheS then rates each picture on the specified attribute byturning a potentiometer knob on his response unit,which moves a pointer along a labeled scale displayed onthe 611 CRT) Figure 4 shows a photograph of theexperimental setup for the S in the second study.

Read control set-up

C li SPJay l al.e l Ie d scale. and allow

S to practIce ~lth ~O\lng arro~--- 8 l·!she; .bi,tt,~,r;

Display ready signal

S tun:s k~0b

Project slide .ith I face

Display 5calc ~ith novin~ arrow

Store data On ma~nctic tape

Punch, dat a on parer tape

Fig. 5. Transition diagram of the experimental sequence inStudy 2.

159

The S initiates each trial after a ready signal on theCRT by giving the potentiometer knob a good turn.When he has turned the knob far enough. the computeropens the high-speed shutter and a facial expressionpicture is projected on the wall screen. Simultaneously,the labeled rating scale appears on the 611 CRT with thepointer displaced away from where the S previously hadpositioned it. When the S is satisfied with the positionwhere he has moved the pointer, he presses a buttonwith his free hand. This turns off the projection of thepicture and the display of the scale on the 611 CRT. Theprogram records the position of the pointer and thejudgment time, and cycles the projector to the next slideduring the intertrial interval. The stimulus and responsedata are saved on magnetic tape, and statistical analysisis once again performed off-line. Figure 5 shows atransition diagram of the experimental sequence for thesecond study.

A third study in this research program will focus onthe way a receiver integrates pairs of referentialdescriptions from two different communicators. Thisstudy will use the same software and hardware as thefirst experiment, with appropriate controls.

The experimental environment for each of thesestudies is completely controlled by the computerizedsystem, including the display of instructions to the S atthe start of each experiment. This gives completestandardization of the procedure, and allows lesspossibility of E error and suggestion effects. The systempermits great precision in stimulus presentation andtiming. There is a clear separation between trials.minimizing interference from other trials. Likewise,there is a definite order of things within a trial. so thatthe E again knows the informational determinants of the

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S's response. This also permits different components ofthe S's processing time to be separately analyzed.Usingthe Tektronix 611 CRT for the dynamic presentation ofverbal information is extremely efficient, as theinformation is provided in a better paced, more readable,and in a smoother, quieter way than on other devices,e.g., the Teletype printer.

Computers are not yet able to generatealgorithmically on a CRT visual patterns of such highinformation content as these facial expression pictures.Fortunately. however. a computer-controlled slideprojection and shutter system handles the task ofpresenting this type of stimuli very adequately. Therather elegant rating-scale procedure allows easy,accurate, and finely graded recording, and it is wellintegrated with the remaining experimental system.Theentire procedure is highly interestingto Ss.

REFERENCESHulin. W. S,; &: Katz. D. The Frois-Wittmann pictures of facial

expression. Journal of Experimental Psychology, 1935, 18.482-498.

Manis, M., &: van Rooiien, L. Integrating the information inreferential messages. In R. L. Solso (Ed.), Contemporaryu.ue, in cogniiiu« psychology. The Loyola Symposium.Washington, D. C.: Winston, 1973.

Rosenberg, S,; &: Cohen, B. Referential processes of speakers andlisteners. Psychological Review, 1966, 73, 208·231.

Schlosberg, H. The description of facial expressions in terms oftwo dimensions. Journal of Experimental Psychology, 1952,44,229-237.

van Rooijen, L., &: Manis, M. Redundancy and accuracy ofreferential decoding. Paper presented at the MidwestemPsychological Association convention, Cleveland, Ohio, May1972.

NOTEI, Goode, F. M. Software aids for computer CRT displays for

on-line psYchological research. Unpublished manuscript, 1973.

Behav. Res. :\leth. & Instru., 1973, Vol. 5 (2)