Cari Cannon - Academia.edu (original) (raw)
Papers by Cari Cannon
Animal Learning & Behavior, 1999
These experiments examined one way in which the allocation of attentional resources can change pe... more These experiments examined one way in which the allocation of attentional resources can change performance during a visual discrimination task. Pigeons were trained to discriminate visual forms under conditions that produced dimensional contrast. In three experiments, negative training stimuli differed from positive stimuli either along a primary physical dimension alone or along both a primary dimension and an orthogonal dimension, When a negative stimulus differed from positive stimuli along two dimensions, discrimination of that negative stimulus improved. For one type of visual form, discrimination of the positive stimuli declined with orthogonal variation in a negative stimulus, whereas for other visual forms, there was no decline in performance. These results are consistent with a model of dimensional contrast that suggests that differences in the allocation of attentionalresources determine discrimination performance. The results also indicate that the organization of stimulus dimensions plays a crucial role in the allocation of attentional resources in these settings.
Psychological Bulletin, 1996
Operant response rates often change within experimental sessions, sometimes increasing and then d... more Operant response rates often change within experimental sessions, sometimes increasing and then decreasing. The authors attribute these changes to sensitization and habituation to aspects of the experimental situation presented repeatedly (e.g., reinforcers) or for a prolonged time (e.g., the experimental enclosure). They describe several empirical similarities between sensitization-habituation and within-session changes in operant responding. They argue that many alternative explanations for within-session changes in operant responding can be dismissed. They also examine some implications of linking the literatures on habituation and operant responding. Because responding follows a similar pattern in several other cases (e.g., human vigilance, classical conditioning, and unconditioned responding), 2 relatively simple processes may be responsible for the temporal patterning of behavior in a wide variety of situations.
Animal Learning & Behavior, 1999
We examine some implications of an attentional model designed to explain dimensional contrast. Pi... more We examine some implications of an attentional model designed to explain dimensional contrast. Pigeons were trained to discriminate rectangular forms under conditions that produced positive dimensional contrast. In two experiments, the spacing of training stimuli was manipulated in ways that should have changed the allocation of attention. Experiment 1 compared the effect of an increased spacing between negative and positive
Behavioural Processes, 1995
Three pigeons responded on variable interval 60-second and variable interval 30-second schedules.... more Three pigeons responded on variable interval 60-second and variable interval 30-second schedules. The duration of access to mixed grain was varied from 2-to 20-seconds per reinforcer in different conditions. Within-session patterns of responding did not differ when subjects received 2- versus 20-seconds access to the reinforcer for the schedule providing the lower rate of reinforcement. However, the within-session decreases in responding were steeper when reinforcers were 20-seconds than when they were 2-seconds for the schedule providing the higher rate of reinforcement. These results indicate that satiation is not necessary to produce within-session changes in responding, but it may contribute to those changes at high rates of reinforcement.
Behavioural Processes, 1998
Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple va... more Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple variable-interval 1-min, variable-interval 1-min schedule during 60-min baseline sessions. The obtained pattern of responding was an early-session increase in responding followed by a relatively constant rate of responding during the remainder of the session. In the experimental conditions of experiment 1, sessions were interrupted by a blackout or timeout lasting either 5, 10, or 30 min. Responding following 5-or 10-min interruptions resembled the constant rate of responding late in the baseline sessions. However, responding increased before 30-min interruptions and increased again after the interruption. This change in the pattern of responding was best described as a 'restarting' of the within-session pattern of responding. In experiment 2, a 30-min blackout interrupted sessions. However, reinforcers were presented intermittently during the blackout. Responding did not restart following the 30-min blackout-with-reinforcers condition. These results suggest that the mere presentation of reinforcers is sufficient to maintain within-session changes in responding.
Animal Learning & Behavior, 1999
These experiments examined one way in which the allocation of attentional resources can change pe... more These experiments examined one way in which the allocation of attentional resources can change performance during a visual discrimination task. Pigeons were trained to discriminate visual forms under conditions that produced dimensional contrast. In three experiments, negative training stimuli differed from positive stimuli either along a primary physical dimension alone or along both a primary dimension and an orthogonal dimension, When a negative stimulus differed from positive stimuli along two dimensions, discrimination of that negative stimulus improved. For one type of visual form, discrimination of the positive stimuli declined with orthogonal variation in a negative stimulus, whereas for other visual forms, there was no decline in performance. These results are consistent with a model of dimensional contrast that suggests that differences in the allocation of attentionalresources determine discrimination performance. The results also indicate that the organization of stimulus dimensions plays a crucial role in the allocation of attentional resources in these settings.
Animal Learning & Behavior, 1999
We examine some implications of an attentional model designed to explain dimensional contrast. Pi... more We examine some implications of an attentional model designed to explain dimensional contrast. Pigeons were trained to discriminate rectangular forms under conditions that produced positive dimensional contrast. In two experiments, the spacing of training stimuli was manipulated in ways that should have changed the allocation of attention. Experiment 1 compared the effect of an increased spacing between negative and positive
Animal Learning & Behavior, 1994
Rats and pigeons responded for food delivered according to multiple schedules. The session length... more Rats and pigeons responded for food delivered according to multiple schedules. The session length varied from 10 to 120 min, and the programmed rate of reinforcement varied from 15 to 240 reinforcers per hour. Response rates usually changed systematically within experimental sessions. For both rats and pigeons, responding reached a peak after an approximately constant amount of time since the beginning of the session, regardless of session length. When rats, but not pigeons, served as subjects, the peak rates of responding occurred later in the session and the within-session changes were smaller for lower than for higher rates of reinforcement. The similarities between the results for rats and for pigeons when session length varied suggest that at least one of the factors that produces the within-session changes in responding is shared by the present species, responses, and reinforcers. The differences in results when rate of reinforcement varied are more difficult to interpret.
Psychological Bulletin, 1996
Operant response rates often change within experimental sessions, sometimes increasing and then d... more Operant response rates often change within experimental sessions, sometimes increasing and then decreasing. The authors attribute these changes to sensitization and habituation to aspects of the experimental situation presented repeatedly (e.g., reinforcers) or for a prolonged time (e.g., the experimental enclosure). They describe several empirical similarities between sensitization-habituation and within-session changes in operant responding. They argue that many alternative explanations for within-session changes in operant responding can be dismissed. They also examine some implications of linking the literatures on habituation and operant responding. Because responding follows a similar pattern in several other cases (e.g., human vigilance, classical conditioning, and unconditioned responding), 2 relatively simple processes may be responsible for the temporal patterning of behavior in a wide variety of situations.
Behavioural Processes, 1996
were conducted during which undergraduates responded during a variable-interval (VI) 60-second op... more were conducted during which undergraduates responded during a variable-interval (VI) 60-second operant task. The first experiment consisted of either three 60-minute sessions or three 30-minute sessions. During Experiment 1 subjects were informed as to the length of the session and the number of sessions that would be conducted. During the second experiment subjects were told that they would be participating in three 60-minute sessions but they actually participated in one 30-minute session. During Experiment 1 the rate of responding increased significantly within the sessions for 30-minute sessions but did not change significantly for 60-minute sessions. Response rate did not change during the 30-minute session in Experiment 2. The results of these experiments demonstrate that, under certain circumstances, rate of responding changes within-sessions for humans. The experiments also provide some evidence that a prospective factor influences the rate of responding within an experimental session for human subjects. 03%6357/96/$15.00 6 1996 Elsevier Science B.V. All rights reserved SSDI 0376-6357(95)00010-O J.M. Roll et ul./Behauiourcrl Procrs.ses 36 (1996) I-10 3
Behavioural Processes, 1998
Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple va... more Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple variable-interval 1-min, variable-interval 1-min schedule during 60-min baseline sessions. The obtained pattern of responding was an early-session increase in responding followed by a relatively constant rate of responding during the remainder of the session. In the experimental conditions of experiment 1, sessions were interrupted by a blackout or timeout lasting either 5, 10, or 30 min. Responding following 5-or 10-min interruptions resembled the constant rate of responding late in the baseline sessions. However, responding increased before 30-min interruptions and increased again after the interruption. This change in the pattern of responding was best described as a 'restarting' of the within-session pattern of responding. In experiment 2, a 30-min blackout interrupted sessions. However, reinforcers were presented intermittently during the blackout. Responding did not restart following the 30-min blackout-with-reinforcers condition. These results suggest that the mere presentation of reinforcers is sufficient to maintain within-session changes in responding.
Behavioural Processes, 1998
Pigeons were trained to discriminate two types of visual forms that could vary in two orthogonal ... more Pigeons were trained to discriminate two types of visual forms that could vary in two orthogonal dimensions. One set of stimuli was designed to have relatively integral dimensions, while the other set of stimuli was intended to have relatively separable dimensions, for the pigeon. A first experiment provided evidence that the dimensions of our two stimulus sets differed in the degree of separability. The second experiment examined the effect of increased stimulus range on discrimination of the two stimulus sets. Results from this experiment indicated that increases in range in either relevant or irrelevant dimensions reduced discrimination for the integral stimulus set. For the separable stimulus dimensions, however, performance declined only with increased stimulus range along a relevant dimension. In the third experiment, stimulus range was increased along either one or two dimensions of the stimulus. Correlated changes in stimulus range along two dimensions had an impact only for integral stimuli. In summary, these experiments demonstrate that the organizational structure of stimulus dimensions determines the impact of increases in stimulus range, probably due to the attentional properties of different stimulus forms.
Behavioural Processes, 1995
Three pigeons responded on variable interval 60-second and variable interval 30-second schedules.... more Three pigeons responded on variable interval 60-second and variable interval 30-second schedules. The duration of access to mixed grain was varied from 2-to 20-seconds per reinforcer in different conditions. Within-session patterns of responding did not differ when subjects received 2- versus 20-seconds access to the reinforcer for the schedule providing the lower rate of reinforcement. However, the within-session decreases in responding were steeper when reinforcers were 20-seconds than when they were 2-seconds for the schedule providing the higher rate of reinforcement. These results indicate that satiation is not necessary to produce within-session changes in responding, but it may contribute to those changes at high rates of reinforcement.
Animal Learning & Behavior, 1999
These experiments examined one way in which the allocation of attentional resources can change pe... more These experiments examined one way in which the allocation of attentional resources can change performance during a visual discrimination task. Pigeons were trained to discriminate visual forms under conditions that produced dimensional contrast. In three experiments, negative training stimuli differed from positive stimuli either along a primary physical dimension alone or along both a primary dimension and an orthogonal dimension, When a negative stimulus differed from positive stimuli along two dimensions, discrimination of that negative stimulus improved. For one type of visual form, discrimination of the positive stimuli declined with orthogonal variation in a negative stimulus, whereas for other visual forms, there was no decline in performance. These results are consistent with a model of dimensional contrast that suggests that differences in the allocation of attentionalresources determine discrimination performance. The results also indicate that the organization of stimulus dimensions plays a crucial role in the allocation of attentional resources in these settings.
Psychological Bulletin, 1996
Operant response rates often change within experimental sessions, sometimes increasing and then d... more Operant response rates often change within experimental sessions, sometimes increasing and then decreasing. The authors attribute these changes to sensitization and habituation to aspects of the experimental situation presented repeatedly (e.g., reinforcers) or for a prolonged time (e.g., the experimental enclosure). They describe several empirical similarities between sensitization-habituation and within-session changes in operant responding. They argue that many alternative explanations for within-session changes in operant responding can be dismissed. They also examine some implications of linking the literatures on habituation and operant responding. Because responding follows a similar pattern in several other cases (e.g., human vigilance, classical conditioning, and unconditioned responding), 2 relatively simple processes may be responsible for the temporal patterning of behavior in a wide variety of situations.
Animal Learning & Behavior, 1999
We examine some implications of an attentional model designed to explain dimensional contrast. Pi... more We examine some implications of an attentional model designed to explain dimensional contrast. Pigeons were trained to discriminate rectangular forms under conditions that produced positive dimensional contrast. In two experiments, the spacing of training stimuli was manipulated in ways that should have changed the allocation of attention. Experiment 1 compared the effect of an increased spacing between negative and positive
Behavioural Processes, 1995
Three pigeons responded on variable interval 60-second and variable interval 30-second schedules.... more Three pigeons responded on variable interval 60-second and variable interval 30-second schedules. The duration of access to mixed grain was varied from 2-to 20-seconds per reinforcer in different conditions. Within-session patterns of responding did not differ when subjects received 2- versus 20-seconds access to the reinforcer for the schedule providing the lower rate of reinforcement. However, the within-session decreases in responding were steeper when reinforcers were 20-seconds than when they were 2-seconds for the schedule providing the higher rate of reinforcement. These results indicate that satiation is not necessary to produce within-session changes in responding, but it may contribute to those changes at high rates of reinforcement.
Behavioural Processes, 1998
Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple va... more Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple variable-interval 1-min, variable-interval 1-min schedule during 60-min baseline sessions. The obtained pattern of responding was an early-session increase in responding followed by a relatively constant rate of responding during the remainder of the session. In the experimental conditions of experiment 1, sessions were interrupted by a blackout or timeout lasting either 5, 10, or 30 min. Responding following 5-or 10-min interruptions resembled the constant rate of responding late in the baseline sessions. However, responding increased before 30-min interruptions and increased again after the interruption. This change in the pattern of responding was best described as a 'restarting' of the within-session pattern of responding. In experiment 2, a 30-min blackout interrupted sessions. However, reinforcers were presented intermittently during the blackout. Responding did not restart following the 30-min blackout-with-reinforcers condition. These results suggest that the mere presentation of reinforcers is sufficient to maintain within-session changes in responding.
Animal Learning & Behavior, 1999
These experiments examined one way in which the allocation of attentional resources can change pe... more These experiments examined one way in which the allocation of attentional resources can change performance during a visual discrimination task. Pigeons were trained to discriminate visual forms under conditions that produced dimensional contrast. In three experiments, negative training stimuli differed from positive stimuli either along a primary physical dimension alone or along both a primary dimension and an orthogonal dimension, When a negative stimulus differed from positive stimuli along two dimensions, discrimination of that negative stimulus improved. For one type of visual form, discrimination of the positive stimuli declined with orthogonal variation in a negative stimulus, whereas for other visual forms, there was no decline in performance. These results are consistent with a model of dimensional contrast that suggests that differences in the allocation of attentionalresources determine discrimination performance. The results also indicate that the organization of stimulus dimensions plays a crucial role in the allocation of attentional resources in these settings.
Animal Learning & Behavior, 1999
We examine some implications of an attentional model designed to explain dimensional contrast. Pi... more We examine some implications of an attentional model designed to explain dimensional contrast. Pigeons were trained to discriminate rectangular forms under conditions that produced positive dimensional contrast. In two experiments, the spacing of training stimuli was manipulated in ways that should have changed the allocation of attention. Experiment 1 compared the effect of an increased spacing between negative and positive
Animal Learning & Behavior, 1994
Rats and pigeons responded for food delivered according to multiple schedules. The session length... more Rats and pigeons responded for food delivered according to multiple schedules. The session length varied from 10 to 120 min, and the programmed rate of reinforcement varied from 15 to 240 reinforcers per hour. Response rates usually changed systematically within experimental sessions. For both rats and pigeons, responding reached a peak after an approximately constant amount of time since the beginning of the session, regardless of session length. When rats, but not pigeons, served as subjects, the peak rates of responding occurred later in the session and the within-session changes were smaller for lower than for higher rates of reinforcement. The similarities between the results for rats and for pigeons when session length varied suggest that at least one of the factors that produces the within-session changes in responding is shared by the present species, responses, and reinforcers. The differences in results when rate of reinforcement varied are more difficult to interpret.
Psychological Bulletin, 1996
Operant response rates often change within experimental sessions, sometimes increasing and then d... more Operant response rates often change within experimental sessions, sometimes increasing and then decreasing. The authors attribute these changes to sensitization and habituation to aspects of the experimental situation presented repeatedly (e.g., reinforcers) or for a prolonged time (e.g., the experimental enclosure). They describe several empirical similarities between sensitization-habituation and within-session changes in operant responding. They argue that many alternative explanations for within-session changes in operant responding can be dismissed. They also examine some implications of linking the literatures on habituation and operant responding. Because responding follows a similar pattern in several other cases (e.g., human vigilance, classical conditioning, and unconditioned responding), 2 relatively simple processes may be responsible for the temporal patterning of behavior in a wide variety of situations.
Behavioural Processes, 1996
were conducted during which undergraduates responded during a variable-interval (VI) 60-second op... more were conducted during which undergraduates responded during a variable-interval (VI) 60-second operant task. The first experiment consisted of either three 60-minute sessions or three 30-minute sessions. During Experiment 1 subjects were informed as to the length of the session and the number of sessions that would be conducted. During the second experiment subjects were told that they would be participating in three 60-minute sessions but they actually participated in one 30-minute session. During Experiment 1 the rate of responding increased significantly within the sessions for 30-minute sessions but did not change significantly for 60-minute sessions. Response rate did not change during the 30-minute session in Experiment 2. The results of these experiments demonstrate that, under certain circumstances, rate of responding changes within-sessions for humans. The experiments also provide some evidence that a prospective factor influences the rate of responding within an experimental session for human subjects. 03%6357/96/$15.00 6 1996 Elsevier Science B.V. All rights reserved SSDI 0376-6357(95)00010-O J.M. Roll et ul./Behauiourcrl Procrs.ses 36 (1996) I-10 3
Behavioural Processes, 1998
Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple va... more Rats pressed levers for sweetened condensed milk reinforcers delivered according to a multiple variable-interval 1-min, variable-interval 1-min schedule during 60-min baseline sessions. The obtained pattern of responding was an early-session increase in responding followed by a relatively constant rate of responding during the remainder of the session. In the experimental conditions of experiment 1, sessions were interrupted by a blackout or timeout lasting either 5, 10, or 30 min. Responding following 5-or 10-min interruptions resembled the constant rate of responding late in the baseline sessions. However, responding increased before 30-min interruptions and increased again after the interruption. This change in the pattern of responding was best described as a 'restarting' of the within-session pattern of responding. In experiment 2, a 30-min blackout interrupted sessions. However, reinforcers were presented intermittently during the blackout. Responding did not restart following the 30-min blackout-with-reinforcers condition. These results suggest that the mere presentation of reinforcers is sufficient to maintain within-session changes in responding.
Behavioural Processes, 1998
Pigeons were trained to discriminate two types of visual forms that could vary in two orthogonal ... more Pigeons were trained to discriminate two types of visual forms that could vary in two orthogonal dimensions. One set of stimuli was designed to have relatively integral dimensions, while the other set of stimuli was intended to have relatively separable dimensions, for the pigeon. A first experiment provided evidence that the dimensions of our two stimulus sets differed in the degree of separability. The second experiment examined the effect of increased stimulus range on discrimination of the two stimulus sets. Results from this experiment indicated that increases in range in either relevant or irrelevant dimensions reduced discrimination for the integral stimulus set. For the separable stimulus dimensions, however, performance declined only with increased stimulus range along a relevant dimension. In the third experiment, stimulus range was increased along either one or two dimensions of the stimulus. Correlated changes in stimulus range along two dimensions had an impact only for integral stimuli. In summary, these experiments demonstrate that the organizational structure of stimulus dimensions determines the impact of increases in stimulus range, probably due to the attentional properties of different stimulus forms.
Behavioural Processes, 1995
Three pigeons responded on variable interval 60-second and variable interval 30-second schedules.... more Three pigeons responded on variable interval 60-second and variable interval 30-second schedules. The duration of access to mixed grain was varied from 2-to 20-seconds per reinforcer in different conditions. Within-session patterns of responding did not differ when subjects received 2- versus 20-seconds access to the reinforcer for the schedule providing the lower rate of reinforcement. However, the within-session decreases in responding were steeper when reinforcers were 20-seconds than when they were 2-seconds for the schedule providing the higher rate of reinforcement. These results indicate that satiation is not necessary to produce within-session changes in responding, but it may contribute to those changes at high rates of reinforcement.