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A laboratory for developmental psychologists
lOURNAL
OF EXPERIMENTAL
A
Laboratory
CHELD
for
PSYCHOLOGY
11,
5&62 (1971)
Developmental
CAROL 0. ECKERMAN, HARRIET L. RHEINGOLD, University of North Carolina,
Psychologists1 AND
Chapel
RICHARD
A.
HELWIG
Hill
The main features of the laboratories for developmental psychologists at Chapel Hill are described. These features include: A flexible spatial arrangement of experimental rooms; a grouping of the rooms into three independent units for the conduct of research with immature organisms of different ages and species; central apparatus that controls the stimulating and recording equipment; viewing areas that permit the observation of behavior in several roo.ms; auditory int.ercommunication between all pairs of rooms ; and self-contained automated devices to aid the experimenter or the observer in his tasks. These characteristics make the laboratories useful for a variety of studies.
The laboratories for the study of the behavior of young organisms at Chapel Hill have proved so useful for research and the training of students that a description of their main features may be helpful to investigators planning similar laboratories. These features include adaptability of the rooms to many experimental procedures and to subjects of different ages and a number of different species; central apparatus that controls the stimulating and recording equipment and permits the simultaneous conduct of two studies, as well as the quick transition from one study to another; and observation through one-way vision windows of almost all experimental rooms, many from a common space. The laboratories are housed in Davie Hall, a new building erected for the Psychology Department in the fall of 1967. The laboratories are part of the wing on the second floor devoted to developmental psychology. They occupy the central core of the wing, and are surrounded on three sides by a corridor. (The fourth side is bounded by rooms that can eventually be incorporated into the developmental laboratories but now are classrooms and laboratories for students of other programs.) The corridor separates the laboratories from the offices of faculty, graduate students, laborat.ory personnel, and secretaries. The offices are outside rooms, ringing the corridor. This arrangement of laboratories, ‘Support for these Health Service Grant to Marcus B. Waller. tus, and equipment to
laboratories was provided, in part, by United States Public HD-01107. Major credit for the design of Davie Hall goes We thank Heinz J. Whitefoot for adapting the space, apparacurrent research. 54
LABORATORY
FOR
DEVELOPMENTAL
55
PSYCHOLOGISTS
corridor, and offices possesses several advantages. The laboratories are shielded from street noises by the corridor and offices, and from the visual distractions of outside windows. The corridor provides access at many points to the experimental space, and its noises, moderate as they are, are controlled by cautionary signs when experiments are run. Then, too, experimenters and other laboratory personnel are but a step from the laboratories. SPATIAL
ARRANGEMENTS
OF THE
LABORATORY
The experimental rooms are organized around two main observation areas, A and H (Fig. 1) ; from each area, several experimental rooms can be vie :wed :.
,...
y:,,.. j,‘i”.. :~:..:.;;~;~~;:~~;
:
::i; .:.. :..),:,.‘: :::: _... I:.:‘: .;, ..:: :: .,.... :: ;., ;,: I:.;::, ),.‘::,.:‘::.:.:.: ‘,.,.,. ..‘...L ..,:, > .:.: : ._...: ,:~.~:;:~;::~,“.j ..:;:..: ,r::,.:i) i:, ;;j:. :; .; .:.:., ,.;,.. . . .,..,.:;,. .,,( i: ‘i
;;j;:
.:,.,.:
:‘.
:.‘:..
.: ....,:~,.‘~~.~~~, :: .. .; ..,;,...... :.. ,.:;,“..‘;:.. ., .;:.. .; :’ ‘.),i. :.,;;;‘.:‘.::;~
., .
:.
..,., ::; _.: ,.:.
:
.‘.,,:,.:.:‘.,~. ,.. .::.,; : ,:’
”
.’ . “. :
CORRIDOR
FIG.
1. Spatial
arrangement
of the laboratories.
The larger observation area (A) is also the control room for the laboratories; it contains the major controlling apparatus for the entire research space. Cables connect the second observation area and each experimental room to this controlling apparatus. The controlling apparatus and cables will be described later. Note here that controlling apparatus refers to only the electronic programming apparatus; equipment, in distinction, refers to the instruments or devices, such as tape recorders, event recorders, and projectors, that are controlled by the apparatus.
56
ECKERMAN,
RHEINGOLD,
AND
HELWIG
Equipment for monitoring the operation of the controlling apparatus, as well as additional recording or stimulating equipment, may be located in the second observation area (H) or in any room, according to the dictates of a study. From either main observation area, then, laboratory personnel can set the stimulating conditions for a study, observe and record the behavior occurring in a number of rooms, and monitor the apparatus. Costly duplication of apparatus is avoided, and the potential for simultaneous viewing of a number of experimental rooms is gained. The experimental rooms together with the observation areas form three relatively independent research units. Rooms B, C, D, E, and F with the control and observation area (A) form Unit 1; Rooms G, I, and J and the second observation area (H) form Unit 2; and Rooms K, L, and M with A form Unit 3. Room G can function as part of Units I or 2. And the one-way window between Rooms E and F allows either room to be used as an experimental room, and the other room as an observation room. The independence of these units provides facilities for three concurrent sets of research projects and, even, for projects using different species. At the present time, for example, Unit 1 is used for studies of the human infant’s social and exploratory behavior; Unit 2, for studies of adultchild interaction; and Unit 3, for studies of the effects of early experience on rats. A later section will describe how the controlling apparatus facilitates both simultaneous research projects within a research unit and the consecutive use of the same space for different studies. Two further characteristics of the organization of the research space contribute to its flexibility: the connecting rooms within Units 1 and 3; and the similar rooms within each unit. The connecting rooms greatly expand the number of spatial arrangements available; up to six rooms can be joined together. The pairs of similar rooms can be furnished to duplicate an experimental setting for the simultaneous study of two subjects (Ss), or to provide two different settings for the study of one 8. COSTROL
OF
GENERAL
STIMULATING
CONDITIONS
In this and the following sections we present the broad outline of a workable laboratory. Hence, the provisions for presenting stimuli and recording responses are described in only general terms and technical specifications are omitted. The latter are available on request, but it is likely that the experimenter’s choice will depend on local conditions and his particular research needs. The experimental rooms are constructed of cinderblock and plasterboard walls painted in light shades, ceilings of poured concrete, and
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
57
floors of white vinyl-asbestos tiles. Their general appearance can be modified according to the study; furniture, rugs, or drapes can be added, and false ceilings or walls constructed. Fluorescent light fixtures provide general-purpose illumination for the experimental rooms. Additional incandescent cove lights in Rooms B, C, and D provide a continuously adjustabIe source of illumination when needed. Silicon Controlled Rectifier dimmers in Room A govern the illumination of the incandescent bulbs mounted behind sheets of white, translucent plastic. With the cove lights, illumination at the floor can range up to 398 lm/m”; the addition of the fluorescent lights provides a maximum illumination of 1109 lm/m2. In the absence of exterior windows, these two systems of artificial light allow adequate control of the lighting. A central heating and air-conditioning system provides a fairly constant level of temperat,ure and humidity, which can be altered as required. The sinks in some of the experimental rooms provide for caretaking of the human infant and animal Ss, as well as for the cleaning of test materials. VISUAL
COMMUNICATION
Windows in the walls of all but one of the experimental rooms allow observation of behavior occurring in the rooms as well as the delivery of visual stimuli into them. The windows, approximately 1.6 m wide, extend from 1.0 to 1.8m above the floor of the experiment,al rooms. Their width, roughly equivalent to the entire wall of the smaller research rooms, provides an unobstructed view of all sections of the room. ,411 windows consist of two sheets of plate glass, separated by an air space to reduce sound transmission. For most windows, one sheet of glass has a single silvered surface (one-way glass) ; the second is clear glass. The windows of Rooms B, C, and D, however, contain instead of the sheet of one-way glass a sheet composed of three equal-sized vertical panels, the two side panels of one-way glass and the middle panel of clear glass. The one-way portion allows observers (OS) and stimulating equipment to be hidden from the S’s view; the clear portion allows the delivery of visual stimuli into the experimental rooms and the filming of behavior within them. Masks can be affixed to the clear glass panel to cover all but that portion necessary for filming or stimulating; a sliding wood panel covers the clear panel when not in use. A sheet of drafting film affixed to either the clear glass or one-way glass portion of the window makes an effective screen for the rear projection of visual stimuli. Projection, however, need not be limited to the surface of the window; visual stimuli can be positioned anywhere in the
58
ECKERMAN,
RHEINGOLD,
AND
HELWIG
rooms by a system of mirrors. And visual stimuli need not even be projected; a lighted stimulus box, for example, could be placed behind the clear glass and objects positioned within it. Opaque curtains are hung on both sides of the one-way windows. On the side of the observation spaces they are drawn to restrict an S’s view of the control room when increased illumination is needed there; on the side of the experimental rooms, when a degree of privacy for the S is desired. Although the windows allow direct observation of the experimental rooms, visual access, of course, need not be direct. Cameras can be mounted anywhere in the rooms and their output monitored either immediately on a TV monitor or at a later time from slides, movies, or video tape. AUDITORY
COMMUNICATION
The laboratories are equipped for the transmission of sound between experimental and observation rooms. A lavalier microphone with a cardioid reception pattern hangs from the center of the ceiling of the experimental rooms. The microphones are connected to amplifiers in the control and observation area (A) ; the amplifiers are connected through the controlling apparatus to a loudspeaker in the observation room and (or) to one channel of a two-channel tape recorder. In this way, the sounds of the experimental rooms-the S’s vocal productions, the experimenter’s (E’s) instructions to the 8, and any programmed auditory stimuli-are detected and recorded. Loudspeakers are mounted at the ceilings of experimental rooms. The controlling apparatus selectively distributes the auditory input, whether pure tones, noise, music, or human speech, to the loudspeakers. A lavalier microphone is plugged into cable outlets in the observation rooms to connect with the controlling apparatus; this arrangement allows the 23’or 0 to give directions through the microphone to the mother, S, or another E in the experimental rooms. One could also thus direct the performance of students learning research procedures. With the same microphone the 0 can dictate accounts of behavior and procedures to be recorded on one channel of a tape recorder, while the auditory input from the experimental rooms is recorded on the other; the O’s comments thus correspond exactly in time to the S’s vocalizations. The 0 determines with a push-to-talk switch what portion of his speech will be transmitted to the experimental room. Sound in fact can be transmitted between any two rooms, not just between experimental rooms and the two main observation rooms. An 0 stationed in Room F, for example, can listen to or talk to the X in Room E, as well as to another 0 in the control and observation room. This
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
59
flexibility results from the connecting of the microphones and speakers of all rooms to equipment in the control room. Thus, with a system of switches, the E decides which rooms to listen to, which rooms to record from, which rooms to deliver auditory stimuli to, and which rooms to talk int,o. THE
CONTROLLING
APPBRATUS
The controlling apparatus, located in the control and observation area, is composed of two units of solid-state electronic equipment. The two units allow two experiments to proceed simultaneously without interference. Each unit consists of digital components (logic functions, time bases, flip-flop memories, lamp drivers, and reed-relay drivers) wired to a program-receiver panel having 1632 contacts arranged in a 4%column by 34-row array. Connections to the stimulating and recording equipment, to manipulanda, and to the observer’s recording instruments (described in the next section) appear on the receiver panel. A prewired program patch-board, inserted into the receiver panel, makes all connections of the logic for an experiment. The program patch-boards add to the flexibility of the laboratories because different types of experimental sessions can be preprogrammed, each on a separate board. By inserting the appropriate board, the same set of controlling apparatus and peripheral equipment can serve successively different experimental purposes. Since no rewiring is necessary, switching from one experiment to another is not only practically instantaneous, but error free. The controlling apparatus can also transform responses into other measures: in current work, for example, analog levels of the physical activity of an infant seated in a high chair, fitted with strain gauges, are quantized into one of five ranges. The primary recording device is a digital data-acquisition system which encodes information about the onset and offset of events (up to 64 events are possible) and their time of occurrence (1-msec resolution) on IBM System/360 compatible, magnetic tape. Computers then produce detailed reports of the events of each experimental session. Other recording devices, such as event recorders, yield an immediate “picture” of the session. The controlling apparatus, audio system, event recorders, and dataacquisition system are mounted together in four racks that utilize a total of 1.4 rn? of floor space in the control and observation room. The cornpactness of the apparatus provides ample space for several OS at any of the five observation windows and for the storage of research supplies.
60
ECKERMAN,
OBSERVER’S
RHEINGOLD,
RECORDING
AND
HELWIG
INSTRUMENT
Since many of the responses of interest to developmental psychologists still require the use of the human observer, the laboratories are equipped with portable recording instruments. They are metal boxes (18 X 23 X 5 cm) containing a toggle switch, eight silent push-button switches, an indicator light, and a jack for attaching headphones. With the toggle switch the 0 (or the E) can start t,he trial and the necessary equipment and apparatus. By depressing the buttons he records the occurrence and duration of up to eight behavioral or stimulus events; the button switches record on both the event recorder and the magnet’ic tape of the dataacquisition system. Illumination of the light indicates the passage of time during a study and can be differentially programmed for separate studies. The headphones isolate the 0 from the sounds of the observation room and allow selective auditory input-Ss vocalizations or an auditory time signal. The instruments are plugged into outlets beneath the observation windows and are thus connected by cables to the controlling apparatus. Provisions for two instruments at each window allow checks of the amount of agreement between two OS. Although the outlets for cables connect the observer’s recording instruments with the controlling apparatus in current work, they could instead connect other response-detecting systems with the controlling apparatus. Similarly, a device containing a number of manipulanda and stimulus display panels, placed in an experimental room and connected to the controlling apparatus, could record an S’s responses automatically, as well as program antecedent and consequent stimulus changes. RESEARCH
IN
THE
LABORATORIES
Some recent uses of the laboratories will demonstrate their suitability for a variety of research projects. Studies of the human infant’s social and exploratory behavior are carried out in Unit 1. Room F serves as a reception room for mother and infant and Room D as a place for adapting the infant to the laboratory setting and the E. Rooms B, C, and E are used for the tests. For example, a mother and her creeping infant are placed in Room E, and Rooms B and C are furnished with different stimulating objects (the doors are left open) ; the objects may be strange or familiar persons or toys, or toys varying in complexity or sensory feedback. The level of illumination can differ from room to room, and Room G can be incorporated in the design. Apparatus in the control room automatically times the duration of trials. Photocells at the doorways record entries and exits, and yield measures of durations of time spent in the different rooms. The OS behind
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
61
the one-way windows record the frequency and duration of such infant responses as visual regard, smiling, and manipulating of objects. The infant’s vocalizations are recorded on audio tape. In Unit 2, Dr. Brian Coates studied how adults of both sexes use verbal statements to train black and white school-age children on a discrimination problem. Here in Room J the child and adult sit at opposite sides of a table with a low barrier between them. The child responds to the problem by depressing keys. The adult does not see the child’s response but is “told” it by the illumination of one of a series of lights before him. Which light is illuminated is determined not by the child’s response, but by an 0 in observation area H who follows some prearranged schedule. The adult in t’urn responds with one of a number of specified verbal statements. Unit 3 provides both housing and testing space for studies by Dr. Robert T. Brown of the effects of differential early rearing of rats. Rats are reared from birth in different environments, and the effects are analyzed by learning tasks. Most testing requires the presence of an 0 within the test rooms. At other times, the unit is used to study the object-approach behavior of precocial birds as the result of different’ial rearing. In the past,, litters of kittens with their mothers were reared in Rooms L and M of Unit 3. The kitt’en’s development was charted by means of checklists and by daily observation from behind the one-way glass. At different ages, a kitten’s behavior was recorded in a strange environment-alone, with his mother, or a littermate; or in the home environment without mother or littermates. The home environment was the room in which the kitten was reared from birth, either Room L or M; the strange environment was the other room, similar in size and physical arrangement t’o the home room but emptied of furnishings and cleaned with a disinfectant. A microphone transmitted the kitten’s vocalizations to a tape recorder; an 0 behind one-way glass measured locomotor activity by marking the kitten’s position within the grid formed by the floor tiles; a second 0 dictated additional observations of the kitten’s behavior. Other uses of the laboratories come to mind. The smaller rooms, for example, would be suitable for studies of infant percept.ion and learning. They are large enough to include the mother, and so provide a setting for studies of mother-infant interaction. With children of all ages the smaller rooms are suitable for normative studies, as well as for many kinds of learning studies. The larger rooms make possible the study of social interplay between two or more children. The sets of similar rooms present interesting possibilities, as do the connecting doors. And, although one unit is here set aside for the study of small animals, other units can be
62
ECKERMAN,
RHEINGOLD,
AND
HELWIG
similarly used; alternatively, all units could be used for the study of children. The addition of specialized equipment would also expand the uses of the laboratories. Physiological recording devices could monitor a subject’s respiration, heart rate, and EEG. Pressure-sensitive floors could monitor a subject’s movements in space. Sound-deadening materials would aid studies of audition and baffles, studies of vision. The possibility of recording by telemetry could also be considered. In short, the flexibility of the spatial arrangements and the capabilities of the controlling apparatus-with the possibility of adding further stimulating, recording, or reinforcing equipment-make the laboratories suitable for many types of studies.
OF EXPERIMENTAL
A
Laboratory
CHELD
for
PSYCHOLOGY
11,
5&62 (1971)
Developmental
CAROL 0. ECKERMAN, HARRIET L. RHEINGOLD, University of North Carolina,
Psychologists1 AND
Chapel
RICHARD
A.
HELWIG
Hill
The main features of the laboratories for developmental psychologists at Chapel Hill are described. These features include: A flexible spatial arrangement of experimental rooms; a grouping of the rooms into three independent units for the conduct of research with immature organisms of different ages and species; central apparatus that controls the stimulating and recording equipment; viewing areas that permit the observation of behavior in several roo.ms; auditory int.ercommunication between all pairs of rooms ; and self-contained automated devices to aid the experimenter or the observer in his tasks. These characteristics make the laboratories useful for a variety of studies.
The laboratories for the study of the behavior of young organisms at Chapel Hill have proved so useful for research and the training of students that a description of their main features may be helpful to investigators planning similar laboratories. These features include adaptability of the rooms to many experimental procedures and to subjects of different ages and a number of different species; central apparatus that controls the stimulating and recording equipment and permits the simultaneous conduct of two studies, as well as the quick transition from one study to another; and observation through one-way vision windows of almost all experimental rooms, many from a common space. The laboratories are housed in Davie Hall, a new building erected for the Psychology Department in the fall of 1967. The laboratories are part of the wing on the second floor devoted to developmental psychology. They occupy the central core of the wing, and are surrounded on three sides by a corridor. (The fourth side is bounded by rooms that can eventually be incorporated into the developmental laboratories but now are classrooms and laboratories for students of other programs.) The corridor separates the laboratories from the offices of faculty, graduate students, laborat.ory personnel, and secretaries. The offices are outside rooms, ringing the corridor. This arrangement of laboratories, ‘Support for these Health Service Grant to Marcus B. Waller. tus, and equipment to
laboratories was provided, in part, by United States Public HD-01107. Major credit for the design of Davie Hall goes We thank Heinz J. Whitefoot for adapting the space, apparacurrent research. 54
LABORATORY
FOR
DEVELOPMENTAL
55
PSYCHOLOGISTS
corridor, and offices possesses several advantages. The laboratories are shielded from street noises by the corridor and offices, and from the visual distractions of outside windows. The corridor provides access at many points to the experimental space, and its noises, moderate as they are, are controlled by cautionary signs when experiments are run. Then, too, experimenters and other laboratory personnel are but a step from the laboratories. SPATIAL
ARRANGEMENTS
OF THE
LABORATORY
The experimental rooms are organized around two main observation areas, A and H (Fig. 1) ; from each area, several experimental rooms can be vie :wed :.
,...
y:,,.. j,‘i”.. :~:..:.;;~;~~;:~~;
:
::i; .:.. :..),:,.‘: :::: _... I:.:‘: .;, ..:: :: .,.... :: ;., ;,: I:.;::, ),.‘::,.:‘::.:.:.: ‘,.,.,. ..‘...L ..,:, > .:.: : ._...: ,:~.~:;:~;::~,“.j ..:;:..: ,r::,.:i) i:, ;;j:. :; .; .:.:., ,.;,.. . . .,..,.:;,. .,,( i: ‘i
;;j;:
.:,.,.:
:‘.
:.‘:..
.: ....,:~,.‘~~.~~~, :: .. .; ..,;,...... :.. ,.:;,“..‘;:.. ., .;:.. .; :’ ‘.),i. :.,;;;‘.:‘.::;~
., .
:.
..,., ::; _.: ,.:.
:
.‘.,,:,.:.:‘.,~. ,.. .::.,; : ,:’
”
.’ . “. :
CORRIDOR
FIG.
1. Spatial
arrangement
of the laboratories.
The larger observation area (A) is also the control room for the laboratories; it contains the major controlling apparatus for the entire research space. Cables connect the second observation area and each experimental room to this controlling apparatus. The controlling apparatus and cables will be described later. Note here that controlling apparatus refers to only the electronic programming apparatus; equipment, in distinction, refers to the instruments or devices, such as tape recorders, event recorders, and projectors, that are controlled by the apparatus.
56
ECKERMAN,
RHEINGOLD,
AND
HELWIG
Equipment for monitoring the operation of the controlling apparatus, as well as additional recording or stimulating equipment, may be located in the second observation area (H) or in any room, according to the dictates of a study. From either main observation area, then, laboratory personnel can set the stimulating conditions for a study, observe and record the behavior occurring in a number of rooms, and monitor the apparatus. Costly duplication of apparatus is avoided, and the potential for simultaneous viewing of a number of experimental rooms is gained. The experimental rooms together with the observation areas form three relatively independent research units. Rooms B, C, D, E, and F with the control and observation area (A) form Unit 1; Rooms G, I, and J and the second observation area (H) form Unit 2; and Rooms K, L, and M with A form Unit 3. Room G can function as part of Units I or 2. And the one-way window between Rooms E and F allows either room to be used as an experimental room, and the other room as an observation room. The independence of these units provides facilities for three concurrent sets of research projects and, even, for projects using different species. At the present time, for example, Unit 1 is used for studies of the human infant’s social and exploratory behavior; Unit 2, for studies of adultchild interaction; and Unit 3, for studies of the effects of early experience on rats. A later section will describe how the controlling apparatus facilitates both simultaneous research projects within a research unit and the consecutive use of the same space for different studies. Two further characteristics of the organization of the research space contribute to its flexibility: the connecting rooms within Units 1 and 3; and the similar rooms within each unit. The connecting rooms greatly expand the number of spatial arrangements available; up to six rooms can be joined together. The pairs of similar rooms can be furnished to duplicate an experimental setting for the simultaneous study of two subjects (Ss), or to provide two different settings for the study of one 8. COSTROL
OF
GENERAL
STIMULATING
CONDITIONS
In this and the following sections we present the broad outline of a workable laboratory. Hence, the provisions for presenting stimuli and recording responses are described in only general terms and technical specifications are omitted. The latter are available on request, but it is likely that the experimenter’s choice will depend on local conditions and his particular research needs. The experimental rooms are constructed of cinderblock and plasterboard walls painted in light shades, ceilings of poured concrete, and
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
57
floors of white vinyl-asbestos tiles. Their general appearance can be modified according to the study; furniture, rugs, or drapes can be added, and false ceilings or walls constructed. Fluorescent light fixtures provide general-purpose illumination for the experimental rooms. Additional incandescent cove lights in Rooms B, C, and D provide a continuously adjustabIe source of illumination when needed. Silicon Controlled Rectifier dimmers in Room A govern the illumination of the incandescent bulbs mounted behind sheets of white, translucent plastic. With the cove lights, illumination at the floor can range up to 398 lm/m”; the addition of the fluorescent lights provides a maximum illumination of 1109 lm/m2. In the absence of exterior windows, these two systems of artificial light allow adequate control of the lighting. A central heating and air-conditioning system provides a fairly constant level of temperat,ure and humidity, which can be altered as required. The sinks in some of the experimental rooms provide for caretaking of the human infant and animal Ss, as well as for the cleaning of test materials. VISUAL
COMMUNICATION
Windows in the walls of all but one of the experimental rooms allow observation of behavior occurring in the rooms as well as the delivery of visual stimuli into them. The windows, approximately 1.6 m wide, extend from 1.0 to 1.8m above the floor of the experiment,al rooms. Their width, roughly equivalent to the entire wall of the smaller research rooms, provides an unobstructed view of all sections of the room. ,411 windows consist of two sheets of plate glass, separated by an air space to reduce sound transmission. For most windows, one sheet of glass has a single silvered surface (one-way glass) ; the second is clear glass. The windows of Rooms B, C, and D, however, contain instead of the sheet of one-way glass a sheet composed of three equal-sized vertical panels, the two side panels of one-way glass and the middle panel of clear glass. The one-way portion allows observers (OS) and stimulating equipment to be hidden from the S’s view; the clear portion allows the delivery of visual stimuli into the experimental rooms and the filming of behavior within them. Masks can be affixed to the clear glass panel to cover all but that portion necessary for filming or stimulating; a sliding wood panel covers the clear panel when not in use. A sheet of drafting film affixed to either the clear glass or one-way glass portion of the window makes an effective screen for the rear projection of visual stimuli. Projection, however, need not be limited to the surface of the window; visual stimuli can be positioned anywhere in the
58
ECKERMAN,
RHEINGOLD,
AND
HELWIG
rooms by a system of mirrors. And visual stimuli need not even be projected; a lighted stimulus box, for example, could be placed behind the clear glass and objects positioned within it. Opaque curtains are hung on both sides of the one-way windows. On the side of the observation spaces they are drawn to restrict an S’s view of the control room when increased illumination is needed there; on the side of the experimental rooms, when a degree of privacy for the S is desired. Although the windows allow direct observation of the experimental rooms, visual access, of course, need not be direct. Cameras can be mounted anywhere in the rooms and their output monitored either immediately on a TV monitor or at a later time from slides, movies, or video tape. AUDITORY
COMMUNICATION
The laboratories are equipped for the transmission of sound between experimental and observation rooms. A lavalier microphone with a cardioid reception pattern hangs from the center of the ceiling of the experimental rooms. The microphones are connected to amplifiers in the control and observation area (A) ; the amplifiers are connected through the controlling apparatus to a loudspeaker in the observation room and (or) to one channel of a two-channel tape recorder. In this way, the sounds of the experimental rooms-the S’s vocal productions, the experimenter’s (E’s) instructions to the 8, and any programmed auditory stimuli-are detected and recorded. Loudspeakers are mounted at the ceilings of experimental rooms. The controlling apparatus selectively distributes the auditory input, whether pure tones, noise, music, or human speech, to the loudspeakers. A lavalier microphone is plugged into cable outlets in the observation rooms to connect with the controlling apparatus; this arrangement allows the 23’or 0 to give directions through the microphone to the mother, S, or another E in the experimental rooms. One could also thus direct the performance of students learning research procedures. With the same microphone the 0 can dictate accounts of behavior and procedures to be recorded on one channel of a tape recorder, while the auditory input from the experimental rooms is recorded on the other; the O’s comments thus correspond exactly in time to the S’s vocalizations. The 0 determines with a push-to-talk switch what portion of his speech will be transmitted to the experimental room. Sound in fact can be transmitted between any two rooms, not just between experimental rooms and the two main observation rooms. An 0 stationed in Room F, for example, can listen to or talk to the X in Room E, as well as to another 0 in the control and observation room. This
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
59
flexibility results from the connecting of the microphones and speakers of all rooms to equipment in the control room. Thus, with a system of switches, the E decides which rooms to listen to, which rooms to record from, which rooms to deliver auditory stimuli to, and which rooms to talk int,o. THE
CONTROLLING
APPBRATUS
The controlling apparatus, located in the control and observation area, is composed of two units of solid-state electronic equipment. The two units allow two experiments to proceed simultaneously without interference. Each unit consists of digital components (logic functions, time bases, flip-flop memories, lamp drivers, and reed-relay drivers) wired to a program-receiver panel having 1632 contacts arranged in a 4%column by 34-row array. Connections to the stimulating and recording equipment, to manipulanda, and to the observer’s recording instruments (described in the next section) appear on the receiver panel. A prewired program patch-board, inserted into the receiver panel, makes all connections of the logic for an experiment. The program patch-boards add to the flexibility of the laboratories because different types of experimental sessions can be preprogrammed, each on a separate board. By inserting the appropriate board, the same set of controlling apparatus and peripheral equipment can serve successively different experimental purposes. Since no rewiring is necessary, switching from one experiment to another is not only practically instantaneous, but error free. The controlling apparatus can also transform responses into other measures: in current work, for example, analog levels of the physical activity of an infant seated in a high chair, fitted with strain gauges, are quantized into one of five ranges. The primary recording device is a digital data-acquisition system which encodes information about the onset and offset of events (up to 64 events are possible) and their time of occurrence (1-msec resolution) on IBM System/360 compatible, magnetic tape. Computers then produce detailed reports of the events of each experimental session. Other recording devices, such as event recorders, yield an immediate “picture” of the session. The controlling apparatus, audio system, event recorders, and dataacquisition system are mounted together in four racks that utilize a total of 1.4 rn? of floor space in the control and observation room. The cornpactness of the apparatus provides ample space for several OS at any of the five observation windows and for the storage of research supplies.
60
ECKERMAN,
OBSERVER’S
RHEINGOLD,
RECORDING
AND
HELWIG
INSTRUMENT
Since many of the responses of interest to developmental psychologists still require the use of the human observer, the laboratories are equipped with portable recording instruments. They are metal boxes (18 X 23 X 5 cm) containing a toggle switch, eight silent push-button switches, an indicator light, and a jack for attaching headphones. With the toggle switch the 0 (or the E) can start t,he trial and the necessary equipment and apparatus. By depressing the buttons he records the occurrence and duration of up to eight behavioral or stimulus events; the button switches record on both the event recorder and the magnet’ic tape of the dataacquisition system. Illumination of the light indicates the passage of time during a study and can be differentially programmed for separate studies. The headphones isolate the 0 from the sounds of the observation room and allow selective auditory input-Ss vocalizations or an auditory time signal. The instruments are plugged into outlets beneath the observation windows and are thus connected by cables to the controlling apparatus. Provisions for two instruments at each window allow checks of the amount of agreement between two OS. Although the outlets for cables connect the observer’s recording instruments with the controlling apparatus in current work, they could instead connect other response-detecting systems with the controlling apparatus. Similarly, a device containing a number of manipulanda and stimulus display panels, placed in an experimental room and connected to the controlling apparatus, could record an S’s responses automatically, as well as program antecedent and consequent stimulus changes. RESEARCH
IN
THE
LABORATORIES
Some recent uses of the laboratories will demonstrate their suitability for a variety of research projects. Studies of the human infant’s social and exploratory behavior are carried out in Unit 1. Room F serves as a reception room for mother and infant and Room D as a place for adapting the infant to the laboratory setting and the E. Rooms B, C, and E are used for the tests. For example, a mother and her creeping infant are placed in Room E, and Rooms B and C are furnished with different stimulating objects (the doors are left open) ; the objects may be strange or familiar persons or toys, or toys varying in complexity or sensory feedback. The level of illumination can differ from room to room, and Room G can be incorporated in the design. Apparatus in the control room automatically times the duration of trials. Photocells at the doorways record entries and exits, and yield measures of durations of time spent in the different rooms. The OS behind
LABORATORY
FOR
DEVELOPMENTAL
PSYCHOLOGISTS
61
the one-way windows record the frequency and duration of such infant responses as visual regard, smiling, and manipulating of objects. The infant’s vocalizations are recorded on audio tape. In Unit 2, Dr. Brian Coates studied how adults of both sexes use verbal statements to train black and white school-age children on a discrimination problem. Here in Room J the child and adult sit at opposite sides of a table with a low barrier between them. The child responds to the problem by depressing keys. The adult does not see the child’s response but is “told” it by the illumination of one of a series of lights before him. Which light is illuminated is determined not by the child’s response, but by an 0 in observation area H who follows some prearranged schedule. The adult in t’urn responds with one of a number of specified verbal statements. Unit 3 provides both housing and testing space for studies by Dr. Robert T. Brown of the effects of differential early rearing of rats. Rats are reared from birth in different environments, and the effects are analyzed by learning tasks. Most testing requires the presence of an 0 within the test rooms. At other times, the unit is used to study the object-approach behavior of precocial birds as the result of different’ial rearing. In the past,, litters of kittens with their mothers were reared in Rooms L and M of Unit 3. The kitt’en’s development was charted by means of checklists and by daily observation from behind the one-way glass. At different ages, a kitten’s behavior was recorded in a strange environment-alone, with his mother, or a littermate; or in the home environment without mother or littermates. The home environment was the room in which the kitten was reared from birth, either Room L or M; the strange environment was the other room, similar in size and physical arrangement t’o the home room but emptied of furnishings and cleaned with a disinfectant. A microphone transmitted the kitten’s vocalizations to a tape recorder; an 0 behind one-way glass measured locomotor activity by marking the kitten’s position within the grid formed by the floor tiles; a second 0 dictated additional observations of the kitten’s behavior. Other uses of the laboratories come to mind. The smaller rooms, for example, would be suitable for studies of infant percept.ion and learning. They are large enough to include the mother, and so provide a setting for studies of mother-infant interaction. With children of all ages the smaller rooms are suitable for normative studies, as well as for many kinds of learning studies. The larger rooms make possible the study of social interplay between two or more children. The sets of similar rooms present interesting possibilities, as do the connecting doors. And, although one unit is here set aside for the study of small animals, other units can be
62
ECKERMAN,
RHEINGOLD,
AND
HELWIG
similarly used; alternatively, all units could be used for the study of children. The addition of specialized equipment would also expand the uses of the laboratories. Physiological recording devices could monitor a subject’s respiration, heart rate, and EEG. Pressure-sensitive floors could monitor a subject’s movements in space. Sound-deadening materials would aid studies of audition and baffles, studies of vision. The possibility of recording by telemetry could also be considered. In short, the flexibility of the spatial arrangements and the capabilities of the controlling apparatus-with the possibility of adding further stimulating, recording, or reinforcing equipment-make the laboratories suitable for many types of studies.