ABSTRACT
Illusion decrement for the Müller-Lyer and Horizontal-Vertical illusions was examined. The experiment consisted of an initial adjustment of an illusion followed by 20 test trials, each with an intervening 60-sec. intertrial interval during which a comparator line and a standard line set to equality were visually inspected for 0, 20, 40, or 60 sec. After each intertrial interval the length of the comparator line was reset by the experimenter to either 0 or 90 cm, and subjects then adjusted its length to perceived equality with the standard line (42 cm). Illusion decrement was inversely related to the duration of inspection for each illusion, with significant reductions in magnitude of illusion observed for all groups. These results support prior demonstrations that perceptual learning mechanisms are operative during brief periods of visual inspection, especially when these periods are followed by the opportunity to make repeated adjustments.
Subject(s)
Attention , Optical Illusions , Orientation , Pattern Recognition, Visual , Adult , Female , Humans , Male , Mental Recall , Reaction TimeABSTRACT
Perceptual error in the Müller-Lyer and the Horizontal-Vertical illusions was quantified using nonparametric signal-detection measures of sensitivity and response bias. Sensitivity scores were positively related to signal strength with the greatest values observed for the strongest signals. Sensitivity at each signal strength did not differ between the two illusions. Response-bias scores were inversely related to signal strength, with the most conservative biases observed for the strongest signals. Response biases for each signal strength were significantly more conservative for the Horizontal-Vertical than for the Müller-Lyer illusion.
Subject(s)
Attention , Optical Illusions , Orientation , Pattern Recognition, Visual , Adult , Discrimination Learning , Female , Humans , Male , Psychophysics , Size PerceptionABSTRACT
The effectiveness of an early intervention program to remediate developmental delays in children age birth to 3 years was examined in part- and full-time groups (Study 1). Significant improvements on age-appropriate measures of developmental standing were observed for both groups, with the greatest gains observed for the full-time group. In Study 2, the stress of parents with developmentally delayed children was measured on the Parental Stress Inventory. Reductions in stress related to children's characteristics and dysfunctional parenting skills were observed on some subscales, supporting prior research which indicated extension of the outcomes of early intervention beyond the child was desirable.
Subject(s)
Developmental Disabilities/rehabilitation , Early Intervention, Educational/methods , Child, Preschool , Cost of Illness , Developmental Disabilities/diagnosis , Developmental Disabilities/psychology , Female , Humans , Infant , Infant, Newborn , Male , Neuropsychological Tests , Parents/psychology , Patient Care Team , Personality Inventory , Treatment OutcomeABSTRACT
Taste detection performance for representatives of the four taste qualities as a function of stimulus volume (5 x 10(-4) to 1 x 1(-1) ml) was examined in rats using high-precision gustometry, computer-controlled operant procedures, nonparametric signal detection measures of sensitivity and responsivity, and blind control procedures. The overall sensitivity index was positively related to stimulus volume (rs = .60), with optimal detection performance attained with a 5 x 10(-3) ml stimulus volume for salty tastants and a 1 x 10(-2) ml stimulus volume for the other taste qualities. The overall responsivity index was inversely related to stimulus volume (rs = -.47), especially for sour and bitter tastants. These results are consistent with prior observations and demonstrate that operant methods using small tastant samples produce sensitive estimates of the rat's taste detection performance and response bias.
Subject(s)
Appetitive Behavior , Attention , Conditioning, Operant , Taste Threshold , Animals , Dose-Response Relationship, Drug , Male , Maltose , Potassium Chloride , Psychophysics , Rats , Sodium Chloride , SucroseABSTRACT
The present study examined procedure-specific differences in the acquisition and retention of perceptual learning using four forms of the Horizontal-Vertical illusion. Training to criterion was conducted using intertrial feedback, continued visual inspection, or yoked-control procedures. Retention of perceptual learning was assessed at posttraining intervals ranging from 1 minute to 1 month. Subjects trained with feedback achieved criterion in fewer trials and showed greater accuracy and short-term retention of perceptual learning on the inverted-T figure and the 1-in. vertical line-production task. The present results show that the correction of inaccurate strategic factors most likely represents the temporary acquisition of compensatory strategies that facilitate performance on simple perceptual-motor skills tasks.
Subject(s)
Attention , Optical Illusions , Orientation , Pattern Recognition, Visual , Retention, Psychology , Adolescent , Adult , Feedback , Female , Humans , Male , Middle AgedABSTRACT
The influences of early crawling experience on motor skill development were examined in children identified by parents as crawlers or noncrawlers during early infancy. Relative to the performance of crawlers, noncrawlers showed lower average and subtest-specific performance on selected measures of the Miller Assessment for Preschoolers. These results, interpreted through Ayres' sensory integration theory and applied to current occupational therapy practice, support Farber's hypothesized importance of early crawling experience in the development of sensory and motor systems of the body and general motor skill development.