Effects of goodness and other properties of patterns on discriminative performance of monkeys

Subsequent to prism adaptation, subjects may be readaptedto their original visual-motor coordination using procedures similar to those occurring during adaptation. It has been argued that such procedures will be moreeffective than allowing for a decay of the aftereffect if normal visual-motor behavior is itself a state of adaptation. In the present study, two readaptation procedures were compared for their effectiveness to four decay and/or controf conditions. Although all groups, except for one decay condition, showed significant reductions in prism aftereffects, only the two readaptation groups showed final aftereffects that were not significantly different from zero.It is argued that readaptation is distinguishable from decay and, further, that the necessary conditions for readaptation can be elucidated with reference to the information discordance hypothesis of prism adaptation. These arguments are primarily based on an extensive analysis inwhich discrepant informationabout the adapted arm’s position is supplied by a nonvisual search task using the two arms.     

Vocal and nonvocal discriminative performance in monkeys

Discriminative performance of a lever press and a vocal call was compared in five macaques. The animals exhibited similar scores for Response Rate, Efficiency, and Error Index. Total vocal responses were slightly higher than total lever responses. Latency for vocal responses was significantly greater than lever press. Similar scores in measures of performance of the two behaviors indicate that discriminative vocalization is not exceedingly difficult. Failure by others to achieve discriminative vocalization in studies employing weak positive-reinforcement contingencies suggest that certain experimental paradigms are unsatisfactory for vocal conditioning.     

Some discriminative properties of fixed ratio performance in the pigeon

The discriminative control over a spatial choice response exercised by prior behavior was studied using a procedure involving discrete exposures to a two-member chained schedule. The initial member (red key) was either a smaller or larger fixed ratio (Mix FR:FR), the completion of which produced, after a 1-sec delay, two white response keys. If the larger FR had been completed as the initial chain member, a single peck on the right white key was reinforced; after the smaller FR, a peck on the left white key was reinforced. Frequencies of unreinforced responses (S(Delta) responses) were determined with several pairs of red-key FRs: 95-5, 75-25, 65-35, 60-40, 58-42 and 50-50. The S(Delta) response frequencies were low through the FR pair 65-35; sharp increases were obtained with pairs 60-40 and 58-42. Later, curves analogous to stimulus generalization functions were obtained using a probe procedure. Finally, the delay interval between completion of a red-key FR and the white-key choice response was manipulated: results were variable, but S(Delta) response frequencies tended to increase with increasing delays.     

Complexity and goodness of dot patterns varying in symmetry

Summary Two experiments were performed to specify stimulus determinants of pattern complexity and pattern goodness. Dot patterns distributed in 3×3 and 4×4 matrices with a rectilinear frame were used in Experiment 1, and dot patterns in hexagonal frameworks with a circular frame were used in Experiment 2. The patterns were invariant for transformations of rotation or reflection, and formed symmetry groups of different orders, i.e., cyclic and dihedral groups. The complexity and goodness of the patterns depended upon such stimulus variables as follows: (1) complexity decreased with the order of symmetry groups with equal weights for cyclic and dihedral groups, whereas goodness increased with the order of both symmetry groups with different weights; (2) the simplicity and goodness of patterns with a vertical axis were greater than those with a horizontal axis and those with an oblique one; (3) the complexity of the patterns that had collinear elements with equal length was rated the simplest; (4) pattern goodness increased as a function of the number of dots and the concentrations of dot to rotation/reflection axis in 3×3 and 4 × 4 matrices. Thus, complexity and goodness of pattern differed with respect to these stimulus variables.     

Effects of partial symmetry, exposure time, and backward masking on judged goodness and reproduction of visual patterns

Six experiments investigated the effects of partial symmetry in visual patterns on judgement of pattern goodness, immediate memory, and learning. In Experiments 1—III pattern goodness ratings were substantially inter-correlated among a self-paced test condition and two conditions producing moderate to severe stimulus degradation (brief tachistoscopic exposure, and backward masking): the less the partial symmetry in a pattern, the lower was the judged goodness of the pattern. In Experiments IV and V immediate reproduction of patterns was observed respectively following exposures of 5-5000 ms, and backward masking. Correct reproduction improved with degree of partial symmetry. Concordant results were found in a free recall learning task (Experiment VI). Correlations between goodness and learning and memory performance for discrete patterns were always substantial. The results strongly suggest that pattern goodness can be appraised reliably and accurately with information processing times too short to permit pattern encoding in short-term visual memory. Evaluation of pattern goodness must therefore rest upon early (precategorical) processing of symmetry features.     

The role of pattern goodness in the reproduction of backward masked patterns.

Four experiments investigated the role of pattern goodness in backward masking using five- and four-dot patterns constructed by placing dots in the cells of a 3 x 3 matrix. In Experiment 1, subjects rated the goodness of these patterns and the results replicated previous work showing that good patterns had few alternatives. In Experiment 2, the dot patterns were the target stimuli in a backward masking task using a variety of masking stimuli. For all masking, good patterns were reproduced more accurately than poor patterns. In Experiment 3, the goodness of the masking stimulus was varied. The results indicated that good patterns were reproduced more accurately (replicating Experiment 2) and that good patterns were less effective as stimulus than were poor patterns. In Experiment 4, a long interstimulus interval which precluded masking was used to determine whether goodness affected encoding or memory. At these intervals, there were no differences among patterns, suggesting that the effect of pattern goodness was on rate of encoding. These results demonstrate the importance of configural properties in pattern perception.     

Effects of ratio reinforcement schedules on discrimination performance by Japanese monkeys

In Experiment 1, Japanese monkeys were trained on three conditional position-discrimination problems with colors as the conditional cues. Within each session, each problem was presented for two blocks of ten reinforcements; correct responses were reinforced under continuous-reinforcement, fixed-ratio 5, and variable-ratio 5 schedules, each assigned to one of the three problems. The assignment of schedules to problems was rotated a total of three times (15 sessions per assignment) after 30 sessions of acquisition training. Accuracy of discrimination increased to a moderate level with fewer trials under CRF than under ratio schedules. In contrast, the two ratio schedules, fixed and variable, were more effective in maintaining accurate discrimination than was CRF. With further training, as asymptotes were reached, accuracy was less affected by the schedule differences. These results demonstrated an interaction between the effects of reinforcement schedules and the level of acquisition. In Experiment 2, ratio sizes were gradually increased to 30. Discrimination accuracy was maintained until the ratio reached 20; ratio 30 strained the performance. Under FR conditions, accuracy increased as correct choice responses cumulated after reinforcement.     

G. E. Moore on goodness and reasons

Several proponents of the ‘buck-passing’ account of value have recently attributed to G. E. Moore the implausible view that goodness is reason-providing. I argue that this attribution is unjustified. In addition to its historical significance, the discussion has an important implication for the contemporary value-theoretical debate: the plausible observation that goodness is not reason-providing does not give decisive support to the buck-passing account over its Moorean rivals. The final section of the paper is a survey of what can be said for and against the buck-passing account and Moore's views about goodness and reasons.     

Effects of criterion-level probing on demonstrating newly acquired discriminative behavior.

The purpose of the study was to determine whether probes of the final criterion-level discrimination administered during and after training provided an accurate measure of acquisition. Training and probe stimuli were designed to make training and probe trials initially very discriminable and then progressively less discriminable as training progressed. Initially, the discrimination required on probe trials was more difficult than the discrimination required on training trials. However, this difference in difficulty was gradually eliminated as training stimuli were topographically altered and made identical to probe stimuli by the end of training. Results showed that while correct responding was maintained throughout training, error patterns occurred on all probe trials administered during training. Error patterns developed regardless of whether probe trials occurred only at the beginning of training sessions (temporally discriminable probes) or were randomly interspersed in the training sessions (temporally indiscriminable probes). Probe error patterns seemed to be controlled by the stimulus properties of training and probe trials. Thus, probes did not measure acquisition as it occurred during training. Probe error patterns were maintained when probes were administered after completion of training. This final measure of acquisition did not agree with the demonstration of acquisition provided by the final training trial. The results suggest that probe trials can measure a different stimulus-response relationship from that trained when training starts with an easier or known discrimination and probes involve a final or criterion test of a more difficult or unknown discrimination. Stimulus control of correct responses versus error patterns is discussed.     

Effects of competition on video-task performance in monkeys (Macaca mulatta)

The effects of competition on performance of a video-formatted task were examined in a series of experiments. Two rhesus monkeys (Macaca mulatta) were trained to manipulate a joystick to shoot at moving targets on a computer screen. The task was made competitive by requiring both animals to shoot at the same target and by rewarding only the animal that hit the target first each trial. The competitive task produced a significant and robust speed-accuracy trade-off in performance. The monkeys hit the target in significantly less time on contested than on uncontested trials. However, they required significantly more shots to hit the target on contested trials in relation to uncontested trials. This effect was unchanged when various schedules of reinforcement were introduced in the uncontested trials. This supports the influence of competition qua competition on performance, a point further bolstered by other findings of of behavioral contrast presented here.     

Effects of maternal employment patterns on adolescents' substance use and other risk-taking behaviors

Employment for mothers with school-age children has generated great concern regarding its possible harmful effects on adolescents and their families. We examined the influence of maternal employment on the risk-taking behavior of adolescents in two-parent families. Three hundred and eighty-nine high school students completed a 48-item survey in which they indicated their mother's and father's employment patterns, and their own risk-taking behaviors (e.g., substance use, driving while under the influence). Results showed no significant effects of maternal employment on adolescent risk-taking behaviors.     

Effects of a pre-aversive stimulus upon oddity performance in monkeys

Two monkeys (Macaca mulatta) were trained to perform an oddity discrimination using automatically projected patterned stimuli. After criteria for both response and discrimination stability were met, a tone followed by shock was superimposed upon the ongoing behavior. Each 60-sec tone was terminated with the onset of a 0.3-sec, 1 to 1.5-ma electric shock. During the tone, baseline responding was partially suppressed but discrimination performance was little altered from the pre-tone period. When shock was raised to 2 to 3 ma, responding was further suppressed, but discrimination performance was again essentially unaltered.     

Moore on beauty and goodness

The Journal of Value Inquiry -