Search Results
Results 201 - 250 of 1388
< 1 2 3 4 5 6 7 8 9 10 >
Hori Sayaka - - 2007
We previously studied a conditioning paradigm to associate the proboscis extension reflex (PER) with monochromatic light (conditioned stimulus; CS) in harnessed honeybees. Here, we established a novel conditioning paradigm to associate the PER with a motion cue generated using graphics interchange format (GIF) animations with a speed of 12 mm/s ...
Bizo Lewis A - - 2007
Three experiments investigated temporal generalization in humans. In Experiment 1, a peak shift effect was produced when participants were given intradimensional discrimination training. In Experiment 2, after training with a standard S+ and generalization testing with an asymmetrical series of durations, generalization gradients moved toward the prevailing adaptation level. In ...
Vasconcelos Marco - - 2007
We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference ...
Homs-Ormo Sandra - - 2007
The effects of posttraining excitotoxic lesions of the pedunculopontine tegmental nucleus (PPTg) on two-way active avoidance after changing the conditioned stimulus (CS) used during prelesion training were examined. Prelesion training was carried out with either a tone or a light as the CS, and this CS was changed during postlesion ...
Cohn Scott I - - 2007
Previous experiments have demonstrated that the simultaneous presentation of independently established discriminative stimuli can control rates of operant responding substantially higher than the rates occasioned by the individual stimuli. This "additive summation" phenomenon has been shown with a variety of different reinforcers (e.g., food, water, shock avoidance, cocaine, and heroin). ...
Lachnit Harald - - 2007
Previous research has shown that conditioned responding in differential skin conductance conditioning increased for reinforced stimuli (CSs+) but remained constant for nonreinforced stimuli (CSs-) due to decreasing reinforcement density. The present two experiments (Experiment 1: Negative patterning; Experiment 2: Positive patterning) were designed to disentangle a possible confound of reinforcement ...
Debert Paula - - 2007
The aim of this study was to evaluate whether emergent conditional relations could be established with a go/no-go procedure using compound abstract stimuli. The procedure was conducted with 6 adult humans. During training, responses emitted in the presence of certain stimulus compounds (A1B1, A2B2, A3B3, B1C1, B2C2, and B3C3) were ...
Swaddle John P - - 2007
Small deviations from bilateral symmetry (fluctuating asymmetries) are cues to fitness differences in some animals. Therefore, researchers have considered whether animals use these small asymmetries as visual cues to determine appropriate behavioral responses (e.g., mate preferences). However, there have been few systematic studies of animals' abilities to visually discriminate such ...
Brown Bruce L - - 2007
The present experiment employed the peak-interval (PI) procedure to study the effect of an intruded cue on timing behavior. Rats were trained on a 30-s PI procedure with a tone cue. Subsequently, a 6-s flashing light was paired off-baseline with foot shock (Experiment 1) or presented alone (Experiment 2). Then, ...
Reed Phil - - 2006
Three experiments were performed to examine the effect of response force on rats' performance on various schedules of reinforcement. Response force was manipulated by changing the weight of the lever in the operant chamber--a heavy lever for high response force and a light lever for low response force. Using a ...
Murphy Eric S - - 2006
This study examined whether habituation, a decrease in responsiveness to a repeatedly presented stimulus, occurs to ethanol reinforcers in alcohol-preferring (P) rats. Three fundamental properties of habituation were evaluated: generality, spontaneous recovery, and dishabituation. In each experiment, P rats' lever pressing was reinforced by 10% ethanol on a variable-interval 15-s ...
Andrzejewski Matthew E - - 2007
Using a successive discrimination procedure with rats, three experiments investigated the contribution of reinforcement rate and amount of S(Delta) exposure on the acquisition of an operant discrimination. S(D) components and were always 2 min in length, while S(Delta) (extinction) components were either 1 min or 4 min in length; responses ...
Flykt Anders - - 2007
Evolutionarily old threat stimuli are likely to require less conscious information processing than threat stimuli of a more recent date. To test this proposal two differential conditioning experiments, with biological threat stimuli (e.g. snakes) in half the groups and cultural threat stimuli (e.g. guns) in the other half, were conducted. ...
Urcuioli Peter J - - 2006
Pigeons learned 2 concurrent simultaneous discriminations in which the pecking of left keys versus right keys was reinforced depending on a color that appeared on one of the keys. When the reinforced choice was to peck directly at the color, accuracy was very high initially, but dropped noticeably with continued ...
Bell Matthew C - - 2007
This study evaluated the effect of a signal on resistance to change using a multiple schedule of reinforcement. Experiment 1 presented pigeons with three schedules: a signaled delay to reinforcement schedule (a two-link chain schedule with a variable-interval 120-s initial link followed by a 5-s fixed-time schedule), an unsignaled delay ...
Chaudhri Nadia - - 2006
RATIONALE: Nicotine self-administration in rats is modest when response-contingent nicotine infusions are delivered alone (primary reinforcement) but robust when nicotine infusions are combined with a mildly reinforcing non-pharmacological stimulus. Furthermore, response-independent (non-contingent) nicotine administration also elevates responding for that same non-pharmacological stimulus, suggesting that in addition to primary reinforcement, nicotine ...
Flagel Shelly B SB Molecular and Behavioral Neuroscience Institute, University of Michigan, 205 Zina Pitcher Place, Ann Arbor, MI, 48109-0720, USA. - - 2007
The way an individual responds to cues associated with rewards may be a key determinant of vulnerability to compulsive behavioral disorders. We studied individual differences in Pavlovian conditioned approach behavior and examined the expression of neurobiological markers associated with the dopaminergic system, the same neural system implicated in incentive motivational ...
Santi Angelo - - 2007
Pigeons were trained in a within-subjects design to discriminate durations of an empty interval and a filled interval. Even when different stimuli were used to mark empty intervals and to signal filled intervals, pigeons judged empty intervals to be longer than equal-length filled intervals. This timing difference was not a ...
Lévy C M - - 2006
The importance of perceived complexity, a "collative property" as defined by [Berlyne, D. E. (1967). Arousal and reinforcement. In Nebraska symposium on motivation (pp. 1-110). University of Nebraska Press], to the dynamic development of preference was investigated. Eighty-six female and 82 male subjects rated their liking for and various collative ...
Lieving Gregory A - - 2006
An observing procedure was used to investigate the effects of alterations in response-conditioned-reinforcer relations on observing. Pigeons responded to produce schedule-correlated stimuli paired with the availability of food or extinction. The contingency between observing responses and conditioned reinforcement was altered in three experiments. In Experiment 1, after a contingency was ...
Guilhardi Paulo - - 2006
Extensive extinction greatly reduces response rate and increases the relative frequency of short interresponse times, but does not affect temporal learning or operant response rate. In each of two experiments, 24 rats were trained in a multiple cued interval procedure with three stimuli (noise, light, and clicker) at three intervals ...
Krägeloh Christian U - - 2006
We investigated the effects of discriminative stimuli on choice in a highly variable environment using a procedure in which multiple two-key concurrent VI VI components changed every 10 reinforcers and were signaled by differential flashes of red and yellow keylights. Across conditions, five pigeons were exposed to a number of ...
Okouchi Hiroto - - 2006
Four pigeons were exposed to two tandem variable-interval differential-reinforcement-of-low-rate schedules under different stimulus conditions. The values of the tandem schedules were adjusted so that reinforcement rates in one stimulus condition were higher than those in the other, even though response rates in the two conditions were nearly identical. Following this, ...
Jozefowiez Jeremie - - 2006
Pigeons were exposed to concurrent schedules for which reinforcement was alternately available at different times for each of two choices. In Experiment 1 (in which reinforcement times progressed arithmetically), overall, but not relative, response rate was timescale invariant. In Experiment 2 (in which reinforcement times progressed geometrically and were more ...
Heim Sabine S Department of Psychology, University of Konstanz, P.O. Box D23, 78457 Konstanz, Germany. - - 2006
The present study was designed to examine effects of learned motivational significance on processing of speech syllables in adults using a classical conditioning paradigm. Aversive white noise (unconditioned stimulus) was paired with two exemplars of /ba/ (conditioned stimulus, CS+) occurring near the category boundary of a 10-item /ba/-da/ continuum. Two ...
Sturz Bradley R - - 2006
A dynamic 3-D virtual environment was constructed for humans as an open-field analogue of Blaisdell and Cook's (2005) pigeon foraging task to determine if humans, like pigeons, were capable of integrating separate spatial maps. Participants used keyboard keys and a mouse to search for a hidden goal in a 4x4 ...
Minster Sara Tepaeru - - 2006
Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional discriminations (Ax-Bx, ...
Steele-Russell Ian I Sensory Neuroscience Laboratory, Texas A & M University System Health Science Center, College Station, TX 77843-1114, USA. - - 2006
The present results show that the common practice of using self-indexing conditioned stimuli (CSs) in research on Pavlovian conditioning is a major source of experimental bias. The typical stimulus used is either a light flash or a sound pulse in a light/sound-shielded chamber. Under these conditions the onset characteristics of ...
Vervliet Bram - - 2007
In a human fear conditioning experiment, with on-line expectancy ratings and electrodermal responding as indices of fear, two neutral stimuli (pictures of geometric shapes) were first established as reliable predictors of an electric shock. In the subsequent extinction phase, the two stimuli were repeatedly presented in compound, without the shock. ...
Bills Carla H - - 2006
Three experiments were conducted using a conditioned taste aversion procedure with rats to examine the effect of nonreinforced presentations of a conditioned stimulus (CS) on its ability to compete with a target stimulus for manifest conditioned responding. Two CSs (A and B) were presented in a serial compound and then ...
Belke Terry W - - 2006
How do animals choose between opportunities to run of different durations? Are longer durations preferred over shorter durations because they permit a greater number of revolutions? Are shorter durations preferred because they engender higher rates of running? Will longer durations be chosen because running is less constrained? The present study ...
Hori Sayaka - - 2006
We studied associative visual learning in harnessed honeybees trained with monochromatic lights associated with a reward of sucrose solution delivered to the antennae and proboscis, to elicit the proboscis extension reflex (PER). We demonstrated five properties of visual learning under these conditions. First, antennae deprivation significantly increased visual acquisition, suggesting ...
Soto Paul L - - 2006
The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate ...
Alsop Brent - - 2006
Three pigeons discriminated between two sample stimuli (intensities of red light). The difficulty of the discrimination was varied over four levels. At each level, the relative reinforcer magnitude for the two correct responses was varied across conditions, and the reinforcer rates were equal. Within levels, discriminability between the sample stimuli ...
Reinhard Günter - - 2006
The aim of the present study was to evaluate whether the anticipatory pupillary dilation response is a useful indicator for the examination of complex differential conditioning problems like patterning. A human fear conditioning procedure with six groups (n=20 each) was used to examine conditioned stimulus (CS) processing when a compound ...
Jennings Dómhnall - - 2006
Three experiments examined absolute (Experiment 1) and relative (Experiments 2a and 2b) duration effects on blocking. In Experiment 1, rats were pretrained with a short or long conditioned stimulus (CS1) followed by food, after which they were given reinforced short-short or long-long CS1-CS2 simultaneous compounds. Compared to overshadowing control groups, ...
da Silva Stephanie P - - 2006
The question of how temporal control of responding might be influenced by contingency changes in other contexts was investigated. Each of three pigeons first was exposed to a two-component multiple schedule in which a two-key free-operant psychophysical procedure operated in one component and a variable-interval schedule operated in the other ...
Lieving L M - - 2006
Studies of temporal discrimination in non-human subjects have reliably shown a choose-short effect: higher matching accuracy on short-duration-sample trials than on long-duration-sample trials. This effect occurs as a function of increasing the delay between the onset of sample and comparison stimuli in a delayed matching-to-sample procedure. The present experiment investigated ...
Godsil Bill P - - 2005
Rats confronted with the onset of a light gradient display a transient increase in locomotion called the activity response (AR) and a dark preference (Godsil & Fanselow, 2004). These experiments demonstrate that the magnitude of the AR can be blunted with Pavlovian fear-conditioning procedures via associative and nonassociative fear. Although ...
Perkins Kenneth A - - 2005
Smokers often experience the acute effects of cigarette smoking while they are engaged in the light physical activity of routine tasks. However, virtually all laboratory-based research on these effects is conducted under conditions of quiet rest and, thus, may not generalize to effects in the natural environment. We examined changes ...
Kearns David N - - 2005
After a tone and a light were established as discriminative stimuli for food-reinforced responding in rats, presenting these stimuli simultaneously produced over three times as many responses as either the tone or light alone. Following this stimulus compounding test, responses during the tone and during the light were not reinforced ...
Williams Leanne M - - 2005
The amygdala has a key role in regulating arousal and vigilance, and responds to both visual and vocal signals of fear, including facial expressions of fear. In this study, we used functional MRI to examine sex differences in the magnitude, extent, lateralization and time course of amygdala responses to facial ...
Friedrich Andrea M - - 2005
Clement, Feltus, Kaiser, and Zentall (2000) found that when pigeons have to work to obtain a discriminative stimulus that is followed by reinforcement, they prefer a discriminative stimulus that requires greater effort over one that requires less effort. The authors suggested that such a preference results from the greater change ...
Le Bourg Eric - - 2005
The learned suppression of photopositive tendencies was studied at the individual level in young flies of both sexes. In a T-maze, flies had to choose between an arm leading to a lighted vial associated with an aversive stimulus (i.e., a solution of quinine chlorhydrate deposited on a filter paper in ...
Weidemann Gabrielle - - 2005
Three experiments demonstrated that, following the extinction of an established conditioned stimulus (CS; e.g., tone), the pairing of an orthogonal stimulus from another modality (e.g., light) with the unconditioned stimulus (US) results in strong recovery of responding to the extinguished CS. This recovery occurred to about an equal degree regardless ...
McClure E A - - 2005
Two experiments used a matching to sample of durations procedure to examine changes in temporal discrimination evoked by D-amphetamine (0.75, 1.50, 2.25 and 3.0 mg/kg i.m.) in pigeons. Responses to one key color were reinforced after long (8-s) stimuli: responses to the alternative key color were reinforced after short (2-s) ...
Shahan Timothy A - - 2005
The effects of rate of conditioned reinforcement on the resistance to change of operant behavior have not been examined. In addition, the effects of rate of conditioned reinforcement on the rate of observing have not been adequately examined. In two experiments, a multiple schedule of observing-response procedures was used to ...
Jovanovic Tanja - - 2005
BACKGROUND: The inability to suppress excessive fear or anxiety is a significant clinical problem. In the laboratory, extinction is a preferred method for the study of fear inhibition; however, in this paradigm the same stimulus causes both elicitation (excitation) and inhibition of fear, making it difficult to know whether an ...
Bremner J Douglas - - 2005
In the conditioned fear paradigm, repeated pairing of an aversive unconditioned stimulus (US) (e.g. electric shock) with a neutral conditioned stimulus (CS) (e.g. bright light) results in a conditioned fear response to the light alone. Animal studies have shown that the amygdala plays a critical role in acquisition of conditioned ...
Eiler William J A WJ 2nd Psychobiology of Addictions Program, Department of Psychology, Indiana University-Purdue University, Indianapolis, Indiana 46202-3275, - - 2005
The relation between ethanol (EtOH) preference and sensitivity to brain stimulation reward (BSR) was examined under multiples schedules of reinforcement in the current study. For comparison, the study also examined the relation between EtOH preference and motivation for a sweet, palatable sucrose solution under similar schedules of reinforcement. To investigate ...
< 1 2 3 4 5 6 7 8 9 10 >