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C A Saslow

Publications and source records attributed to C A Saslow.

5 recordsLinked to original sources
PubMed1987

Lateralization of kinesthetically guided spatial perception.

The present study measured unimanual kinesthetic discrimination for the right and left thumb angular position of male and female right handers without left handed relatives. Each subject's discrimination threshold and constant error were obtained by the Method of Constant Stimuli. Subjects either made an active movement in assessing the standard thumb angle or were passive while the angle was set by the experimenter. Subjects either reported their decision orally or made a non-verbal movement. A difference was found between the thumbs in the direction of more sensitive kinesthetic discrimination by the left thumb (right hemisphere). The left thumb was found to have smaller discrimination threshold of angular position by about 20% over the right thumb. Sex, passive movement mode, and verbal response were not related to the lateralization effect.

Adult↗
PubMed1978

Simultaneous versus successive discrimination of weights: a neuroanatomical interpretation.

Using the Method of Constant Stimuli, difference limens were obtained for lifted weights of 50 to 200 gm. 184 college students were assigned to one of four experimental conditions resulting from the combination of two modes of stimulus presentation with whether the preferred or non-preferred hand was used to judge the standard weight. Simultaneous interhand judgments produced significantly larger Weber Ratios and more variable Constant Errors than were produced by Successive intrahand presentation. This was contrary to earlier work in the visual modality indicating that simultaneous stimulus presentation produced more sensitive discrimination than did successive. The results are interpreted in terms of the neural organization of tactile input.

Brain↗
PubMed1972

Behavioral definition of minimal reaction time in monkeys.

Two monkeys (Macaca mulatta) were trained to press a key after onset of a tone and to release it after a 1-sec fixed foreperiod terminated by a light. The effects of imposing temporal contingencies on key release reaction times were determined by reinforcing only those releases whose latencies from the light fell within a "payoff band", two time limits 50 msec apart located at some delay following the light. Over several days this delay was first gradually decreased, shortening the interval between light and payoff band, and then gradually increased again. For each delay, the median reaction time and a measure of variability were obtained from the latency distribution. For both animals, median latency could be decreased to 180 msec with the variability remaining small. Moving the payoff band still closer to the light resulted in further decrease in median latency but an abrupt increase in variability. This is in agreement with a model for simple reaction time derived from human research which suggests that this increased variability results from the inclusion of high-variability foreperiod time estimations in the latency distribution. These results indicate that interpretation of monkey response latencies as "minimal reaction times" requires examination of temporal reinforcement contingencies and variability of latencies.

Journal Article↗
PubMed1968

Operant control of response latency in monkeys: evidence for a central explantation.

Two monkeys (M. mulatta) were trained to press a telegraph key after onset of a tone and release it quickly in response to a subsequent light or click stimulus occurring after a variable interval. After training first with a fixed time limit on response latency for key release and then with a continuously adjusting limit, reaction time to click was 160 msec and to light, about 200 msec. Temporal contingencies or "payoff bands" were then introduced which reinforced only responses with latencies which fell between two limits 50 msec apart. Feedback was given as to whether each latency was too slow, within the band, or too fast. A trained monkey could precisely center its latency distribution on any 50 msec-wide payoff band located from 200 to 600 msec after the stimulus, with from 60 to 80% of its responses achieving reinforcement. Distribution statistics were comparable to those of trained human subjects. Because such precise timing might be accomplished by a peripheral adjustment, such as changing the manner of holding the key, latency of electromyographic activation was measured in participating arm muscles in one monkey. Electromyographic activation preceded key release by a constant interval, regardless of response latency, indicating a more central mechanism for timing of brief intervals.

Animals↗