Patterning of infant vocal behavior

Three-month-old infants received two consecutive 5-minute periods of adult social stimulation. In both periods the adult talked, smiled, and touched the infant and in a natural manner tried to elicit vocalizations from the infant. In the first period the adult became unresponsive for 5 sec contingent upon each infant vocalization (time-out, negative reinforcement). In the second period the infant received the same number of time-out periods at the same intervals but independently of vocal responding (yoked, noncontingent control). Negative reinforcement did not suppress infant vocal rate, but the contingent withdrawal of social stimulation did cause the infant to pause more frequently between vocal responses. These pauses generally occurred immediately after the contingently, as compared with the noncontingently, delivered time-out period. The infant appears to recognize the difference between contingent and noncontingent stimulation and pauses after the occurrence of the former. Adult social reinforcement changes the pattern and not the rate of infant vocal responding.     

Some models of observer behavior in two-channel auditory signal detection

Five models of 0 behavior in a two-channel exclusive-or (XOR) detection task were evaluated. The models included two types of single-channel and three types of two-channel O. Only the most efficient two-channel model adequately described human performance in a set of monaural and dichotic XOR conditions. Detectability measures derived from the XOR task matched those obtained from separate single-channel control conditions. We concluded that. in this two-channel task. the O’s performance was not limited by any inability to monitor signals arriving simultaneousl.v in two different earphone or two different frequency channels. The implications of this result for two-channel information processing and for multicomponent and sequential signal detectmn are discussed.     

Social elicitation of infant vocal behavior.

The time course and the nature of social elicitation of vocalizations in 3-month-old infants were analyzed. Adult stimulation produced an immediate and significant increase in both the rate and the percent of bursts of vocal sounds of eight infants (Experiment 1). Both response-independent and response-dependent social stimulation were effective in producing increased rates of vocalizations, but only when each of four infants could see the eyes of the adult who delivered the social stimulus (Experiment 2).     

Operant control of vocal behavior in the cat

Evidence of operant control of vocal behavior in the cat is presented: (1) On mult FR 12 S^Δ schedule, cats miaowed rapidly during periods of S^D and much less or not at all during S^Δ. (2) This control was re-established following reversal of stimuli. (3) The frequency distribution of response durations was shifted to both shorter and longer values by the differential reinforcement of shorter or longer response durations respectively. Since both the frequency and duration of vocal responses were shown to be under the control of the schedule of reinforcement, it is concluded that at least some of the vocal behavior of the cat is susceptible to operant control.     

Schedule control of the vocal behavior of Cebus monkeys

The vocal behavior of three Cebus monkeys was maintained by fixed-ratio schedules of response dependent reinforcement at values between fixed-ratio 1 and fixed-ratio 15. In one monkey that was exposed to variable-interval, fixed-interval, and conjunctive fixed-ratio fixed-interval schedules of reinforcement, vocal responding occurred at a low rate, but schedule-appropriate patterns were maintained. The rates and patterns of responding engendered indicated that the vocal operant can be brought under schedule control in the monkey by the use of response-dependent reinforcement.     

Experimental analysis of human vocal behavior: applications of speech-recognition technology

Recent developments in speech recognition make it feasible to apply the technology to study vocal behavior. The present study illustrates the use of this technology to establish functional stimulus classes. Eight students were taught to say nonsense words in the presence of arbitrarily assigned sets of symbols consistent with three three-member experimenter-defined stimulus classes. Computer-controlled speech-recognition software was used to record, analyze, and differentially reinforce vocal responses. When the stimulus classes were established, students were taught to say a new nonsense word in the presence of one member of each stimulus class. Transfer of function was tested subsequently to determine if the novel stimulus names transferred to the remaining stimulus class members. Most subjects required two iterations of the training and testing procedures before transfer occurred. The data illustrate the usefulness of recording vocal behavior during stimulus control procedures and demonstrate the use of speech-recognition technology. The paper also describes the current state of speech-recognition technology and suggests several other areas of research that might benefit from using vocal behavior as its primary datum.     

Cortical control of conditioned and spontaneous vocal behavior in rhesus monkeys

Rhesus monkeys were trained on a discriminative conditioning of vocalizations paradigm, a task that requires volitional vocal control. The monkeys' spontaneous vocal and other social behavior was also assessed. Each monkey then underwent ablation of anterior cingulate cortex, ablation of the homologus of Broca's and Wernicke's areas, or no lesion. The anterior cingulate lesions severely disrupted both conditioned and spontaneous vocal behavior, but had no effect on nonvocal social behavior or on a discriminative conditioning task requiring a nonvocal response. The lesions of the homologs of Broca's and Wernicke's areas had no effects on the behaviors studied. These findings have implications for the comparative neurology of primate vocalization and speech.     

Laboratory experimentation at the center for computer-based behavior studies

The Center for Computer-Based Behavioral Studies (CCBS) is designed around a time-shared computer system to make its informational and technological resources available to behavioral scientists and policy analysts at remote locations (through the ARPA Network and through dial-in phone lines) as well as in our own laboratory. The principal goal of CCBS is to broaden and expand the capabilities and horizons of behavioral research for studying problems of real-world complexity and theoretical relevance. The principal focus is on strengthening laboratory and associated research methodologies through computer-administered multiperson experiments and gaming simulations.     

The effects of parent-presented models and praise on the vocal behavior of their children

The combined and separate effects of parent-presented models and praise on specific vocalizations of three children (15, 17, and 20 months old) were investigated. The frequency of a specific vocalization was higher when parents modeled and praised it than when they did not. In addition, modeling and praise, when used in combination, had a greater effect on the frequency of specific vocalizations than when used separately. Three additional parents were asked to attempt, by any means they wished, to increase the frequency of a specific vocalization by their children. These parents used modeling almost, exclusively, and the children did not exhibit the specific vocalizations as frequently as did the children whose parents were instructed both to model and praise specific vocalizations.     

Nonverbal concomitants of enacted emotional intensity and positivity: Visual and vocal behavior1

This study focused on how emotional expressions are implied through visual and vocal behaviors. The roles of proportion gaze, glance duration, and vocal loudness in expressing emotional positivity and intensity were examined. Emotional positivity, emotional intensity, and target of the communication were manipulated in a mixed design. Forty-eight female subjects performed a liking or an anger message to a man and to a camera with strong and weak intensity. Videotaped responses were analyzed. Strong emotional intensity conditions evoked more direct gaze regardless of the message positivity or the target of the emotional expression. Longer glances and louder speech were associated with only intense negative emotional expression regardless of the target of the expression. The proportion gaze data support the view that eye contact serves as an intensifier of affective expression. Methodological considerations and questions about generalizability are discussed.     

Co‐occurences of preverbal vocal behavior and motor action in early infancy

This study reports on co‐occurrence of vocal behaviors and motor actions in infants in the prelinguistic stage. Four Japanese infants were studied longitudinally from the age of 6 months to 11 months. For all the infants, a 40 min sample was coded for each monthly period. The vocalizations produced by the infants co‐occurred with their rhythmic actions with high frequency, particularly in the period preceding the onset of canonical babbling. Acoustical analysis was conducted on the vocalizations recorded before and after the period when co‐occurrence took place most frequently. Among the vocalizations recorded in the period when co‐occurrence appeared most frequently, those that co‐occurred with rhythmic action had significantly shorter syllable duration and shorter formant‐frequency transition duration compared with those that did not co‐occur with rhythmic action. The rapid transitions and short syllables were similar to patterns of duration found in mature speech. The acoustic features remained even after co‐occurrence disappeared. These findings suggest that co‐occurrence of rhythmic action and vocal behavior may contribute to the infant’s acquisition of the ability to perform the rapid glottal and articulatory movements that are indispensable for spoken language acquisition.     

Caudal fin branding fish for individual recognition in behavior studies

Caudal fin branding is an inexpensive technique for marking and identifying small, fragile fish. A modified tip on a hand-held soldering pencil is used to cauterize small holes in the caudal fin membrane. The technique is simple to use, appears to cause little trauma to the fish, and lasts for at least several weeks.     

Assessment of the functions of vocal behavior in children with developmental disabilities: a replication

Although experimental analysis methodologies have been useful for identifying the function of a wide variety of target behaviors (e.g., Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994), only recently have such procedures been applied to verbal operants (Lerman et al., 2005). In the current study, we conducted a systematic replication of the methodology developed by Lerman et al. Participants were 4 children who had been diagnosed with developmental disabilities and who engaged in limited vocal behavior. The function of vocal behavior was assessed by exposing target vocal responses to experimental analyses. Results showed that experimental analyses were generally useful for identifying the functions of vocal behavior across all participants.     

Memory for vocal tempo and pitch

Two experiments examined the ability to remember the vocal tempo and pitch of different individuals, and the way this information is encoded into the cognitive system. In both studies, participants engaged in an initial familiarisation phase while attending was systematically directed towards different aspects of speakers’ voices. Afterwards, they received a tempo or pitch recognition task. Experiment 1 showed that tempo and pitch are both incidentally encoded into memory at levels comparable to intentional learning, and no performance deficit occurs with divided attending. Experiment 2 examined the ability to recognise pitch or tempo when the two dimensions co-varied and found that the presence of one influenced the other: performance was best when both dimensions were positively correlated with one another. As a set, these findings indicate that pitch and tempo are automatically processed in a holistic, integral fashion [Garner, W. R. (1974). The processing of information and structure. Potomac, MD: Erlbaum.] which has a number of cognitive implications.     

Simultaneous switching of auditory transients For two-channel presentation

A modification of the Grason-Stadler Series 829 D&E Electronic Switches that enables simultaneous cross-channel presentation of auditory signals at the two ears is described.