Elbert Blakely - Academia.edu (original) (raw)

Papers by Elbert Blakely

Pharmacology, Biochemistry and Behavior, Mar 1, 1986

The behavioral effects of phenytom, phenobarbital, clonazepam, valproic ac,d, and ethosuxlmlde we... more The behavioral effects of phenytom, phenobarbital, clonazepam, valproic ac,d, and ethosuxlmlde were evaluated ,n food-deprived pigeons performing under automamtenance and negative automamtenance procedures Under the automaantenance procedure, brief periods of key dlumlnatlon were followed by food delivery without regard to the subject's behavior In most instances, when drugs were not g~ven tMs procedure engendered high rates of keypecklng dunng almost all key dlummatlons (tnals) Acute admm,stratlons of phenytom (10-20 mg/kg), valprom acid (40-120 mg/kg), and ethosuxlmlde (40-120 mg/kg) produced generally dose-dependent decreases m percent trials with a response and rate of responding Although phenobarbital (30-60 mg/kg) and clonazepam (2 5-7 5 mg/kg) produced httle obv,ous effect on percent trials with a response, these drugs generally increased rate of responding Under the negaUve automamtenance procedure, food dehvery followed only key lllummattons dunng which keypeckang did not occur Keypecklng occurred at a low rate under this procedure, w,th no responses occumng during the majority of key dlumlnattons Thus, th,s procedure appeared to revolve responding ehclted by respondent condmomng but suppressed by the response-dependent om,ss,on of food Across the same dose ranges evaluated under the automamtenance procedure, clonazepam and phenobarbttal generally increased percent tnals with a response and rate of responding in dose-dependent fashion Phenytom s,mflarly increased percent trials w~th a response but had httle consistent effect on rate of responding Ethosuxlmlde and valprolc acid faded to affect responding under th~s procedure Phenobarbital Clonazepam Phenytoln Valpro,c acid Ethosux,mlde Ant~convulsant drugs Respondent condmonlng Pigeons Antlpumshment effects Automamtenance Negative automamtenance

Journal of the Experimental Analysis of Behavior, Mar 1, 1988

Psychological Record, 1991

Four pigeons were given a choice between two sequences of fixed-ratio schedules. The second fixed... more Four pigeons were given a choice between two sequences of fixed-ratio schedules. The second fixed ratio was a fixed-ratio 5 followed by 2-s access to grain in one sequence and a fixed-ratio 45 followed by 8-s access to grain in the alternative. In Phase 1, the initial fixed-ratio schedules of each sequence, which were always equal, varied from fixed-ratio 1 to fixed-ratio 50. At each initial fixed-ratio value, 3-s access to grain and a 0.25-s hopper flash were programmed. When the initial fixed ratio was small, the sequence with the 2-s reinforcer was preferred. Preference switched to the sequence with the 8-s reinforcer when the initial fixed ratio increased. In Phase 2, the effects of a 3-s hopper flash were compared with those of a 0.25-s hopper flash. The results showed that preference for the sequence with the 8-s reinforcer increased with hopper-flash duration. Together, Phase 1 and Phase 2 results show that reinforcer magnitude and ratio size of the second fixed ratio can affect choice, but their relative effects depend on initial fixed-ratio size and reinforcer duration.

Pharmacology, Biochemistry and Behavior, Jun 1, 1986

and valproic acid on learning in pigeons as assayed by a repeated acquisition procedure. PHARMACO... more and valproic acid on learning in pigeons as assayed by a repeated acquisition procedure. PHARMACOL BIOCHEM BEHAV 24(6) 1583-1586, 1986.-The acute and chronic effects of the antiepileptic drugs clonazepam (0.06, 0.13, and 0.25 mg/kg), phenytoin (2.5, 5, and 7.5 mg/kg), ethosuximide (40, 80, and 120 mg/kg), and valproic acid (40, 80, and 120 mg/kg) were evaluated in pigeons responding under a repeated acquisition procedure. At certain doses, acute administrations of all drugs impaired learning (i.e., increased errors) and reduced rate of responding. Appreciable tolerance developed to these effects with chronic exposure, although the physiological mechanism responsible for this outcome is unknown. Clonazepam Phenytoin Ethosuximide Valproic acid Repeated acquisition procedure Tolerance Pigeons

Pharmacology, Biochemistry and Behavior, Jun 1, 1993

/kg) on the reaction time of pigeons were examined. In the reaction time assay, birds were traine... more /kg) on the reaction time of pigeons were examined. In the reaction time assay, birds were trained to depress and hold a foot treadle until a stimulus change occurred. Releases within 2 s of the stimulus change were reinforced with food; premature releases or releases occurring after the 2-s limited hold were not reinforced. At relatively high doses, each of the drugs decreased the percentage of responses that were reinforced. Methaqualone and phencyclidine usually increased median reaction times at these doses, whereas the effects of d-amphetamine on reaction time were less clear.

Psychological Record, 1988

In a discrete-trials procedure, aoult humans chose between two sequential fixed-ratio (FR) schedu... more In a discrete-trials procedure, aoult humans chose between two sequential fixed-ratio (FR) schedules. Points, later exchangeable for money, were given for the completion of each FR. When each sequence produced two points for an equal number of responses overall, the value of the first FR in a sequence did not affect choice. When the values of the first FR in each sequence were equal, subjects preferred the alternative with the smaller second FA. Once a preference was established for the alternative with the smaller overall response requirement, two points were given for completing the second FR of the nonpreferred sequence. This sequence then provided three total points. Preference immediately shifted to the alternative requiring more responses overall (and per point) but offering more points.

Journal of the Experimental Analysis of Behavior, Nov 1, 1992

The present study examined the acquisition of lever pressing in rats under three procedures in wh... more The present study examined the acquisition of lever pressing in rats under three procedures in which food delivery was delayed by 4, 8, and 16 seconds relative to the response. Under the nonresetting delay procedure, food followed the response selected for reinforcement after a specified interval elapsed; responses during this interval had no programmed effect. Under the resetting procedure, the response selected for reinforcement initiated an interval to food delivery that was reset by each subsequent response. Under the stacked delay procedure, every response programmed delivery of food t seconds after its occurrence. Two control groups were studied, one that received food immediately after each lever press and another that never received food. With the exception of the group that did not receive food, responding was established with every procedure at every delay value without autoshaping or shaping. Although responding was established under the resetting delay procedure, response rates were generally not as high as under the other two procedures. These findings support the results of other recent investigations in demonstrating that a response not previously reinforced can be brought to strength by delayed reinforcement in the absence of explicit training.

Bulletin of the psychonomic society, Sep 1, 1986

The effects of clonazepam (0.25-4.0 mg/kg) and phenobarbital (10-80 mg/kg) were examined in pigeo... more The effects of clonazepam (0.25-4.0 mg/kg) and phenobarbital (10-80 mg/kg) were examined in pigeons responding under a multiple fixed-ratio 50 fixed-interval 90-sec schedule offood delivery. When given acutely 30 min prior to testing, the lowest dose of each drug generally increased responding under both components of the multiple schedule, whereas high doses decreased responding. Time-course determinations revealed maximum rate-reducing effects when phenobarbital was given 30 min prior to testing; 15-and 30-min presession intervals were similarly effective with clonazepam. When a 120-min presession interval was used, responding generally exceeded control rates for clonazepam, but not for phenobarbital.

The business of scientists is collecting, interpreting, and disseminating data. A difficult busin... more The business of scientists is collecting, interpreting, and disseminating data. A difficult business it is, but honorable. Or is it? A look at the historical record might suggest otherwise, for it appears that unethical conduct in the name of science, including the falsification of data, is by no means rare. In fact, myriad cases of apparent fraud are evident in the history of science (Broad & Wade, 1982).

Pharmacology, Biochemistry and Behavior, Dec 1, 1988

Although antiepilepsy drugs are used clinically, their behavioral effects are poorly understood. ... more Although antiepilepsy drugs are used clinically, their behavioral effects are poorly understood. The present study examined the effects of mephenytoin and methsuximide, two antiepilepsy medications, on the reaction times of pigeons. Pigeons were trained to depress and hold a foot treadle until a stimulus change occurred. Releases within 2 sec of the stimulus change were reinforced with access to mixed grain; premature releases or releases occurring after the 2-sec limited hold were not reinforced. Mephenytoin (40, 60, 80, 120, and 160 mg/kg) and methsuximide (25, 50, 75, and 100 mg/kg) produced generally dose-dependent increases in median reaction times and decreases in percent responses that were reinforced. The present procedure has not previously been used with pigeons and is a promising technique for the study of reaction time with this species. Mephenytoin Methsuximide Reaction time Pigeons Antiepilepsy Drugs

Behavioral Interventions, Oct 29, 2012

Pediatric occupational therapists often use specific activities associated with deep pressure tou... more Pediatric occupational therapists often use specific activities associated with deep pressure touch as a modality when providing services based in sensory integration theory. This study investigated the effects of these activities contingent on choice responding. Initially, preference assessments identified that activities such as being swaddled in a blanket or sandwiched between halves of a therapy mat were potential reinforcers for each of the three participants. Then, the stimuli were presented contingently under a two-response concurrent schedule. The results suggested that for each participant, the application of these activities functioned as a positive reinforcer. Given that such activities are often used in pediatric occupational therapy interventions, the clinical implications of these findings are discussed.

Psychological Record, Jul 1, 1994

The present experiment examined the effects of different delays of food delivery with and without... more The present experiment examined the effects of different delays of food delivery with and without a response-produced auditory stimulus on the acquisition of a spatially defined operant in rats. The operant was breaking a photoelectric beam located near the ceiling at the rear of the experimental chamber. In five groups of experimentally naive rats, the effects on photobeam-break responses of two different reinforcement delays (4 s and 10 s) with and without a response-produced auditory stimulus were compared during eight 1-hr sessions. In one control group (0-s delay), an immediate (i.e., 0.25-s) reinforcement contingency was in effect and in another control group (no food), responses were measured in the absence of any reinforcement contingencies. Results showed that rates of acquisition and responding were higher with shorter reinforcement delays and when there was a response-produced auditory stimulus. These results extend previous findings showing that neither direct shaping nor immediate reinforcement is necessary for operant conditioning. However, the present results demonstrate that the speed and extent of conditioning depends on the temporal relation between the response and the reinforcer. The findings are discussed in terms of a conditioned reinforcement analysis of the stimuli produced by operant responses. In his book, The Behavior of Organisms, B. F. Skinner (1938) described an experimental manipulation in which he compared the effects of 1-, 2-, 3-, and 4-s delays of reinforcement on the acquisition of lever pressing in rats. Although he reported that "the rates of acceleration are all comparable with those obtained with simultaneous reinforcement" (p. 73), the cumulative records showed that with only one exception at the 4-s delay, the rates of acquisition at the 2-, 3-, and 4-s delays were retarded when compared with simultaneous reinforcement. Skinner attributed these "slight irregularities" to procedural difficulties, namely, the problems inherent in what researchers today would speak of as resetting versus nonresetting delays (see Wilkenfield, Nickel, Blakely, & Poling, 1992). Until recently, only a few experiments (e.g., Harker, 1956; Logan, 1952; Seward & Weldon, 1953) had investigated the effects of delayed reinforcement on discrete responding such as lever pressing. Although these experiments reportedly showed that even short delays can retard or prevent acquisition, recent researchers (e.g., Critchfield & Lattal, 1993; Lattal & Gleeson, 1990) have criticized these early studies for their vague descriptions of training procedures and for not controlling for the possibility of immediate conditioned reinforcement. Interestingly, systematic examination of the effects of delayed reinforcement on the acquisition of discrete responding had not been carried out until very recently (e.g., Critchfield & Lattal, 1993;

Journal of the Experimental Analysis of Behavior, 1990

Pigeons pecked a key under two-component multiple variable-ratio schedules that offered 8-s or 2-... more Pigeons pecked a key under two-component multiple variable-ratio schedules that offered 8-s or 2-s access to grain. Postreinforcement pausing and the rates of responding following the pause (run rates) in each component were measured as a function of variable-ratio size and the size of the lowest ratio in the configuration of ratios comprising each schedule. In one group of subjects, variable-ratio size was varied while the size of the lowest ratio was held constant. In a second group, the size of the lowest ratio was varied while variable-ratio size was held constant. For all subjects, the mean duration of postreinforcement pausing increased in the 2-s component but not in the 8-s component. Postreinforcement pauses increased with increases in variable-ratio size (Group 1) and with increases in the lowest ratio (Group 2). In both groups, run rates were slightly higher in the 8-s component than in the 2-s component. Run rates decreased slightly as variable-ratio size increased, but were unaffected by increases in the size of the lowest ratio. These results suggest that variable-ratio size, the size of the lowest ratio, and reinforcer magnitude interact to determine the duration of postreinforcement pauses.

Behavior Analyst, Apr 1, 1994

Environmental operations may be classified according to whether they have evocative or function-a... more Environmental operations may be classified according to whether they have evocative or function-altering effects. Evocative events, such as the presentation of unconditioned and conditioned stimuli, establishing operations, and discriminative stimuli, serve to increase, decrease, or maintain the momentary frequency of behavior. Function-altering operations, such as operant and respondent conditioning, the correlation of stimuli, and the presentation of certain verbal stimuli, serve to increase, decrease, or maintain the evocative and function-altering (e.g., reinforcing or punishing) functions of other events. This paper expands upon the functional taxonomy of environmental events described by Michael (1993a). The resulting classification scheme should permit behavior analysts to more easily respond to similarities and differences between functional environmental events. This paper discusses implications of the suggested taxonomy for how behavior analysts talk about motivational variables, discriminative stimuli, the operant unit of analysis, and the distinction between operant and respondent conditioning.

The Analysis of Verbal Behavior, Apr 1, 1991

Many definitions of reinforcer and discriminative stimulus found in behavioral texts include a re... more Many definitions of reinforcer and discriminative stimulus found in behavioral texts include a requirement of temporal proximity between stimulus and response. However, this requirement is not consistently adopted. We present additional evidence from a questionnaire that was sent to members of the editorial boards of several behavioral journals showing that there is not universal agreement concerning the temporal parameters accepted in the definitions of reinforcer and discriminative stimulus. We suggest that the disagreement over the definitions of these essential terms ought to be at least addressed if not resolved. Because the discrepancy usually occurs when the behavior of verbal humans is at issue, we urge behavior analysts to be conservative when extending the terms reinforcer and discriminative stimulus from the behavior of nonhumans in the laboratory to human behavior where the effects of many stimuli may depend in part on sophisticated verbal repertoires.

Springer eBooks, 1990

This book obviously deals with psychology, but what is that? This chapter addresses the question ... more This book obviously deals with psychology, but what is that? This chapter addresses the question and also summarizes the historical development of psychology as a discipline. Primary emphasis is placed on the development and defining characteristics of behaviorism, a unique approach to the study of behavior.