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Biomedical subjects

C B FERSTER

Publications and source records attributed to C B FERSTER.

At least 19 recordsLinked to original sources
PubMed1964

SOME NOTES ON TIME OUT FROM REINFORCEMENT.

Pigeons produced food on a fixed-ratio schedule by pecking at one key, and an S(Delta) period by pecking at a second (switching) key. Switching behavior was examined as a function of (a) size of the fixed ratio, (b) whether the S(Delta) was of fixed duration or could be determined by the bird, (c) the introduction of a novel food S(D), (d) extinction of food responding, and (e) the stimuli associated with the S(D) and S(Delta) conditions. No monotonic relationship was obtained between ratio size and switching behavior. Switching behavior was, however, influenced by many variables. The results suggest that an interpretation of switching behavior in terms of its being reinforced by the removal of aversive conditions, is open to considerable question.

Animals↗
PubMed1964

CHAINED VI PERFORMANCE OF PIGEONS MAINTAINED WITH AN ADDED STIMULUS.

Pecks at a first (left) key were reinforced by a partial movement (advance) of the voltmeter behind the key toward the maximum position. When the meter reached maximum deflection, pecks at a second key were continuously reinforced with food. The schedule of reinforcement by which pecking the first key produced a deflection, as well as the size of the deflection, were varied in a series of experiments. The rate of responding on the first key was more affected by changes in the number of steps required to move the meter to the maximum position (the size of the deflection) than by the value of the variable-interval schedule by which pecking produced a meter deflection. The rate at which the bird pecked was low when the meter was near the null position, and high as the meter approached the maximum deflection.

Animals↗
PubMed1963

Fixed-interval performances with added stimuli in monkeys.

The performance of two monkeys, on fixed-interval schedules, was examined with a visual, an auditory and a combined auditory-visual clock. The clock, a voltmeter and/or a variable frequency tone, produced performances different in many aspects from those recorded earlier with pigeons. Instead of the sustained high rates of responding at the optimal settings of the clock, the monkey's rates of responding were often extremely low even though a limited-hold contingency was utilized.

Animals↗
PubMed1963

Intermittent punishment of Sdelta responding in matching to sample.

Incorrect matching responses of two pigeons on matching to sample were either continuously (CRF) or intermittently (FR) followed by a time out (TO). The matching accuracy was examined as a function of both TO duration and TO frequency (ratio size). With intermediate TO durations (10 sec, 1 min), accuracy increased as the frequency of TO increased. With an extremely short (1 sec) and an extremely long (10 min) TO duration, accuracy was poor over the entire range of frequencies.

Animals↗
PubMed1962

The effect of drugs on a fixed-ratio performance suppressed by a pre-time-out stimulus.

Pecking was reinforced by a fixed-ratio schedule with food, and responses during a red light produced a time out. If the bird did not respond during the red light, the light terminated and the bird could complete the FR schedule of positive reinforcement uninterrupted. The bird stopped responding during the red light sufficiently to avoid most of the possible time outs. In general, the pre-time-out stimulus suppressed responding more when the FR schedule was large than when it was small. The occurrence of the pre-time-out stimulus in the fixed ratio produced FR strain and extreme curvature atypical of normal fixed ratios of this size. Amobarbital, pentobarbital, chlorpromazine, and d-amphetamine injected when the FR performance was strained by the pre-time-out procedure produced marked increases in responding. The drug administration lowered the rate of responding only at larger doses; and then this occurred predominantly just after the injection.

Amobarbital↗