Thesis (M.S.)--University of North Carolina at Wilmington, 2006. / Includes bibliographical references (leaves: 95-97)

Thesis (Ph. D.)--State University of New York at Binghamton, Psychology Department, 2008. / Includes bibliographical references.

Thesis (M.A.)--Miami University, Dept. of Psychology, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 21-24).

The area of perceptual decision-making research seeks to understand how our perception of the world affects our judgment. Laboratory investigations of perceptual decision-making concentrate on observers' ability to discriminate among stimuli and their biases towards reporting one stimulus more frequently than others. Choice theories assume that these performance measures are determined by generalization of reinforcement along both stimulus and response dimensions. Historically the majority of research has addressed situations in which the difference among stimuli and resulting consequences of a perceptual decision are static. Consequently, little is known about the dynamics of stimulus and response generalization. The present research investigated the dynamics of discrimination accuracy and response bias by frequently varying differences among stimuli and the outcomes for correct decisions. In Experiment 1, four rats responded in a two-stimulus, two-response detection procedure employing temporal stimuli (short vs. long houselight presentations). Sample stimulus difference was varied over two levels across experimental conditions. A rapid acquisition procedure was employed in which relative reinforcer frequency varied daily. Shifts in response bias were well described by a behavioral model of detection (Davison & Nevin, 1999). Within sessions, bias adjusted rapidly to current reinforcer ratios when the sample stimulus difference was large, but not when the difference was small. In Experiment 2, three rats responded in a five-stimulus, two-response detection procedure employing temporal stimuli. Relative reinforcer frequency was again varied daily. Control by current session reinforcer ratios increased rapidly within sessions in a nearly monotonic fashion. Furthermore, response bias following each sample stimulus was observed within the first few trials of an experimental session. The speed of changes in response bias, especially following an unreinforced probe stimulus, provide strong support for an effective reinforcement process and suggest that this process may operate at a trial-by-trial level. In Experiment 3, three rats responded in a six-stimulus, two-response classification procedure. A repeated-acquisition procedure was employed in which the relationship between classes of short and long sample stimuli and their respective correct comparison locations reversed every 15 sessions. After several reversals, the probabilities of reinforcement for correct classification were also manipulated. In the majority of conditions across subjects, response bias reached half-asymptotic levels more rapidly than did discrimination accuracy. These findings provide some support for a backward chaining account of the acquisition of signal detection performance. An attention-augmented behavioral detection model accurately described the acquisition data; however parameter estimates expressing the probability of attending to sample and comparison stimuli differed widely among subjects. The results of these experiments support the adaptation of dynamic research methodologies to the study of learning in perceptual decision-making tasks. Furthermore, discrimination performance and response bias adapt rapidly to frequent changes in reinforcement contingencies. Quantitative models formulated to describe static performance in detection procedures can be extended to predict dynamic performance. Some theoretical assumptions of these models were supported and others were violated. Overall, this research supports a renewed emphasis on learning in signal detection procedures and suggests that stable behavioral endpoints are at least as much a function of contingency variables as they are of sensory variables.

The aim of this study was to investigate the intra- and intermodal impact of different kinds of early sensory experience on the development of specific neural/perceptual systems. The manipulations of the rats' early experience involved a combination of early binocular deprivation through dark-rearing, somatosensory restriction through cauterization of mystacial vibrissae, and multimodal enrichment through rearing in a complex environment. Specific lesions to somatosensory (Parl) and visual (Oc2M) cortex in differentially reared animals were included in an attempt to gain further insight into the plasticity surrounding manipulations of early stimulation history. Five tasks were used to assess these effects of early rearing condition in combination with later cortical lesions. Behavioral assessment focused on the ability of the animals to encode, abstract, and remember specific relationships between stimuli within the deprived modality itself, their ability to do so with information presented in other modalities, and on the basic species specific behavior. The only effect found was a main effect for rearing condition. Basically, complex-reared rats were more competent on several of the behavioral tasks than were dark-reared rats. However, this result provided little behavioral support for ideas of modality interdependence. Dendritic proliferation is considered to be a general mechanism supporting behavioral change. The subsequent neuroanatomical assessment focused on dendritic branching of neurons in specific cortical areas thought to be most affected by early environmental manipulations. Animals that were raised in a complex environment, but had experienced early tactile restriction through cauterization of vibrissae, showed significantly more dendritic branching than animals from all other rearing conditions in all cortical areas measured. This finding is consistent with ideas of both intra- and intermodal compensation following damage to an early developing modality, as well as behavioral demand acting as a significant factor in determining the impact of early somatosensory restriction. It is reasonable to assume that anatomical changes should be manifested behaviorally. Suggestions for smaller, more restricted studies, that would be more effective in describing the behavioral impact of early manipulations of the environment, were outlined. / Arts, Faculty of / Psychology, Department of / Graduate

Ten developmentally disabled children participated in an assessment of stimulus control and transfer of training. Each subject was taught to perform a simple, nonverbal, imitative task in a training room, and transfer to a novel setting was assessed. During training, subjects were video-taped in order to determine how often each visual stimulus in the training room was looked at. After an initial transfer t est each subject participated in a test of the stimulus control acquired by visual stimuli from the training room. Utilizing two groups (N = 5 each), subjects received an additional transfer test in the novel setting while in the presence of a stimulus that had been either frequently or infrequently looked at during the training process. Subjects tested in the presence of a frequently-looked-at stimulus produced a greater number of correct responses during the transfer tests than subjects tested in the presence of an infrequently-looked-at stimulus. Individual data are also presented fer the subjects. The implications of these results are discussed.

Parent’s ability to implement a skill like time out is considered to have generality when it lasts over time, it appears in environments in which it was not initially trained, and it is seen in use for child behaviors it was not initially trained for. A recent study suggested that parents have difficulty implementing time out in the home when they are supposed to (Jensen et al., 2016). The present study aimed to determine if there were difficulties in stimulus or setting generalization. Six parent participants completed pre and post training in-home naturalistic video observations, as well as a generalization probe role-play test following training. Results showed that parent’s accuracy and parent’s ability to implement when they should were two different skills. Parents scored high for accuracy of steps correct in both the post training in-home observations and the generalization probe role-plays. However, parent’s correct attempts out of the possible opportunities were only moderate in the post training generalization probes and poor in both the pre and post training in-home observations. How to implement time out was the only skill directly taught to parents and not when to implement time out. The authors suggest that knowing when to implement time out may be a generalization deficit and a recognition of opportunities in the home deficit. This version of time out training may benefit from additional training to foster generalization. Future research may benefit from systematically analyzing whether parents can recognize opportunities for time out in the home through other parent in-home videos and if they can, more emphasis on generalization of a skill to the parent’s home would be necessary in training.

A common goal of instructional techniques is to teach skills effectively and efficiently. Matrix training techniques are both effective and efficient as they allow for the emergence of untrained responding to novel stimulus arrangements, a phenomenon known as recombinative generalization. However, it is unclear which type of matrix arrangement best promotes recombinative generalization. The current study compared two common matrix training approaches, an overlapping (OV) design and a non-overlapping (NOV) design, with respect to arranging relations targeted for training. We conducted a replication evaluation of a Wilshire and Toussaint study, and taught two typically-developing preschoolers compound object-action labels in Spanish and used either an OV or NOV matrix training design. Results from both studies demonstrated the participant trained with an OV design produced recombinative generalization and participants trained with a NOV design produced significantly low levels of emergence or none at all. These results suggest that an OV matrix design facilitates recombinative generalization more effectively than a NOV design. Implications for instructional arrangements are discussed.

No description available.

O conceito de controle de estímulos é composto por dois processos correlatos, a discriminação operante e a generalização de estímulos. A relação entre a discriminação e a emissão da resposta de observação tem sido amplamente realizada. A relação entre a generalização e a emissão da resposta de observação, por outro lado, ainda carece de investigação empírica. O principal objetivo deste trabalho foi investigar a duração de fixações aos estímulos em testes de generalização compostos por variações nas dimensões de S+ e por variações nas dimensões de S-. Dez estudantes universitários foram expostos a um procedimento de discriminação sucessiva caracterizado por um esquema múltiplo VI / EXT. Três estímulos Gabor eram apresentados em formação triangular sobre um fundo preto. O estímulo com inclinação das linhas da grade de 45 cumpriu a função de S+, o de inclinação 135 função de S- e os estímulos com linhas horizontais e verticais eram irrelevantes em relação à tarefa. A Fase 1 do treino discriminativo caracterizou-se por um esquema Mult VI 1 seg \\ EXT durante o qual os estímulos discriminativos eram apresentados de forma semi randômica no vértice superior do triangulo. Durante a fase 2, o esquema foi alterado para Mult VI 2 seg \\ EXT e os estímulos alternavam de posição a cada componente. Em seguida ao treino discriminativo cinco participantes foram expostos a um teste de generalização, em extinção, compostos por estímulos de angulações de 15, 30, 45, 60 e 75, enquanto cinco participantes foram expostos a um teste de generalização composto por estímulos de angulações de 105, 120, 135 e 150. Os resultados do teste de generalização composto por variações de S+ demonstram a formação de gradientes de observação em forma de sino. Os resultados do teste de generalização, por outro lado, demonstram a formação de gradientes de observação achatados, em forma de sino e em forma de U. Estes resultados complementam o cenário de compreensão do processo de estabelecimento de controle de estímulos ao demonstrar a formação de gradientes de observação, além disto, indicam que testes de generalização podem ser utilizados como alternativa metodológica à investigação das funções dos estímulos discriminativos sobre a resposta de observação / Stimulus control is a concept based on two related processes, operant discrimination and stimulus generalization. The relation between operant discrimination and observing responses has been widely investigated, while the relation between stimulus generalization and observing responses still lacks empirical research. The aim of this project was to assess the duration of eye fixations during generalization tests on stimulus that were variations of S+ and variations of S-. Ten college students participated of a simple successive discrimination procedure with a Mult VI/EXT schedule. Three Gabor stimuli were arranged in a triangular shape over a black background. The S+ stimulus was the one with lines on a 45° slope and the S- was the one with lines on a 135° slope. Stimuli with vertical (90°) and horizontal (180°) lines were presented as part of the arrangement but were irrelevant to the task. In Phase 1, discriminative training was conducted using a Mult VI 1 s/EXT schedule with S+ and S- alternating in a semi-random sequence on the upper corner of the triangular arrangement. During Phase 2, the schedule changed to Mult VI 2 s/EXT and the position of the S+ and S- varied over the three corners of the triangle in each component. After completing the discriminative training, five participants were exposed to a generalization test, in extinction, with variations from S+, where stimuli of 15°, 30°, 45°, 60°, and 75° were presented. The remaining five participants were exposed to the generation test with stimuli varying from S-, with stimuli of 105°, 120°, 135°, and 150°. Results from the generalization test with variations from S+ show bell-shaped gradients of observing response with peak near S+ and lessened at slopes more distant from S+. On the other hand, gradients from the test conducted with variations from S- were variable, producing flat gradients, bell-shaped, and u-shaped gradients. These results add to the comprehension of stimulus control process by showing gradients of observing behavior and suggest that generalization tests could be used as an alternative to study the role of discriminative stimulus for the observing response