scholarly journals The effects of stimulus distribution form during trace conditioning

2018 ◽  
Vol 72 (2) ◽  
pp. 285-297 ◽  
Author(s):  
Charlotte Bonardi ◽  
Dómhnall J Jennings
Keyword(s):  
Associative Strength ◽  
Auditory Stimulus ◽  
Trace Conditioning ◽  
Response Rates ◽  
Second Phase ◽  
Fixed Duration ◽  
Trace Interval ◽  
Delay Conditioning ◽  
Performance Effect ◽  
Distribution Form

Three experiments examined the effect of distribution form of the trace interval on trace conditioning. In Experiments 1 and 2, two groups of rats were conditioned to a fixed-duration conditioned stimulus (CS) in a trace interval procedure; rats in Group Fix received a fixed-duration trace interval, whereas for rats in Group Var the trace interval was of variable duration. Responding during the CS was higher in Group Var than in Group Fix, whereas during the trace interval this difference in responding reversed—Group Fix showed higher response rates than Group Var. Experiment 3 examined whether the greater response rate observed during the CS in Group Var was due to a performance effect or the acquisition of greater associative strength by the CS. Following trace conditioning, the rats from Experiment 1 underwent a second phase of delay conditioning with the same CS; a 5-s auditory stimulus was presented in compound with the last 5 s of the 15-s CS, and the unconditioned stimulus (US) was delivered at the offset of the CSs. On test with the auditory stimulus alone, subjects in Group Var showed lower response rates during the auditory stimulus than subjects in Group Fix. We interpreted these findings as evidence that the superior responding in Group Var during the CS was a result of it acquiring greater associative strength than in Group Fix.

Eyeblink conditioning contingent on hippocampal theta enhances hippocampal and medial prefrontal responses

2011 ◽  
Vol 105 (5) ◽  
pp. 2213-2224 ◽  
Author(s):  
Ryan D. Darling ◽  
Kanako Takatsuki ◽  
Amy L. Griffin ◽  
Stephen D. Berry
Keyword(s):  
Neural Activity ◽  
Theta Rhythm ◽  
Eyeblink Conditioning ◽  
Trace Conditioning ◽  
Distributed Network ◽  
Field Potentials ◽  
Trace Interval ◽  
Behavioral Learning ◽  
Paired Group ◽  
Hippocampal Theta

Trace eyeblink classical conditioning (tEBCC) can be accelerated by making training trials contingent on the naturally generated hippocampal 3- to 7-Hz theta rhythm. However, it is not well-understood how the presence (or absence) of theta affects stimulus-driven changes within the hippocampus and how it correlates with patterns of neural activity in other essential trace conditioning structures, such as the medial prefrontal cortex (mPFC). In the present study, a brain-computer interface delivered paired or unpaired conditioning trials to rabbits during the explicit presence (T+) or absence (T−) of theta, yielding significantly faster behavioral learning in the T+-paired group. The stimulus-elicited hippocampal unit responses were larger and more rhythmic in the T+-paired group. This facilitation of unit responses was complemented by differences in the hippocampal local field potentials (LFP), with the T+-paired group demonstrating more coherent stimulus-evoked theta than T−-paired animals and both unpaired groups. mPFC unit responses in the rapid learning T+-paired group displayed a clear inhibitory/excitatory sequential pattern of response to the tone that was not seen in any other group. Furthermore, sustained mPFC unit excitation continued through the trace interval in T+animals but not in T−animals. Thus theta-contingent training is accompanied by 1) acceleration in behavioral learning, 2) enhancement of the hippocampal unit and LFP responses, and 3) enhancement of mPFC unit responses. Together, these data provide evidence that pretrial hippocampal state is related to enhanced neural activity in critical structures of the distributed network supporting the acquisition of tEBCC.

scholarly journals Temporal Patterns of Inputs to Cerebellum Necessary and Sufficient for Trace Eyelid Conditioning

2010 ◽  
Vol 104 (2) ◽  
pp. 627-640 ◽  
Author(s):  
Brian E. Kalmbach ◽  
Tatsuya Ohyama ◽  
Michael D. Mauk
Keyword(s):  
Eyelid Conditioning ◽  
Granule Cells ◽  
Mossy Fiber ◽  
Mossy Fibers ◽  
Trace Conditioning ◽  
Trace Interval ◽  
The Us ◽  
Conditioned Responses ◽  
Necessary And Sufficient ◽  
Stimulation Of

Trace eyelid conditioning is a form of associative learning that requires several forebrain structures and cerebellum. Previous work suggests that at least two conditioned stimulus (CS)-driven signals are available to the cerebellum via mossy fiber inputs during trace conditioning: one driven by and terminating with the tone and a second driven by medial prefrontal cortex (mPFC) that persists through the stimulus-free trace interval to overlap in time with the unconditioned stimulus (US). We used electric stimulation of mossy fibers to determine whether this pattern of dual inputs is necessary and sufficient for cerebellar learning to express normal trace eyelid responses. We find that presenting the cerebellum with one input that mimics persistent activity observed in mPFC and the lateral pontine nuclei during trace eyelid conditioning and another that mimics tone-elicited mossy fiber activity is sufficient to produce responses whose properties quantitatively match trace eyelid responses using a tone. Probe trials with each input delivered separately provide evidence that the cerebellum learns to respond to the mPFC-like input (that overlaps with the US) and learns to suppress responding to the tone-like input (that does not). This contributes to precisely timed responses and the well-documented influence of tone offset on the timing of trace responses. Computer simulations suggest that the underlying cerebellar mechanisms involve activation of different subsets of granule cells during the tone and during the stimulus-free trace interval. These results indicate that tone-driven and mPFC-like inputs are necessary and sufficient for the cerebellum to learn well-timed trace conditioned responses.

scholarly journals Persistent activity in a cortical-to-subcortical circuit: bridging the temporal gap in trace eyelid conditioning

2012 ◽  
Vol 107 (1) ◽  
pp. 50-64 ◽  
Author(s):  
Jennifer J. Siegel ◽  
Brian Kalmbach ◽  
Raymond A. Chitwood ◽  
Michael D. Mauk
Keyword(s):  
Eyelid Conditioning ◽  
Mossy Fiber ◽  
Trace Conditioning ◽  
Brain Structures ◽  
Learning Activity ◽  
Persistent Activity ◽  
Trace Interval ◽  
Cerebellar Learning ◽  
Response Expression

We have addressed the source and nature of the persistent neural activity that bridges the stimulus-free gap between the conditioned stimulus (CS) and unconditioned stimulus (US) during trace eyelid conditioning. Previous work has demonstrated that this persistent activity is necessary for trace eyelid conditioning: CS-elicited activity in mossy fiber inputs to the cerebellum does not extend into the stimulus-free trace interval, which precludes the cerebellar learning that mediates conditioned response expression. In behaving rabbits we used in vivo recordings from a region of medial prefrontal cortex (mPFC) that is necessary for trace eyelid conditioning to test the hypothesis that neurons there generate activity that persists beyond CS offset. These recordings revealed two patterns of activity during the trace interval that would enable cerebellar learning. Activity in some cells began during the tone CS and persisted to overlap with the US, whereas in other cells, activity began during the stimulus-free trace interval. Injection of anterograde tracers into this same region of mPFC revealed dense labeling in the pontine nuclei, where recordings also revealed tone-evoked persistent activity during trace conditioning. These data suggest a corticopontine pathway that provides an input to the cerebellum during trace conditioning trials that bridges the temporal gap between the CS and US to engage cerebellar learning. As such, trace eyelid conditioning represents a well-characterized and experimentally tractable system that can facilitate mechanistic analyses of cortical persistent activity and how it is used by downstream brain structures to influence behavior.

scholarly journals Active Inference and Learning in the Cerebellum

2016 ◽  
Vol 28 (9) ◽  
pp. 1812-1839 ◽  
Author(s):  
Karl Friston ◽  
Ivan Herreros
Keyword(s):  
Eyeblink Conditioning ◽  
Predictive Coding ◽  
Trace Conditioning ◽  
Face Validity ◽  
Active Inference ◽  
Focal Lesions ◽  
Delay Conditioning ◽  
Neuronal Populations ◽  
Intrinsic Connectivity ◽  
The Face

This letter offers a computational account of Pavlovian conditioning in the cerebellum based on active inference and predictive coding. Using eyeblink conditioning as a canonical paradigm, we formulate a minimal generative model that can account for spontaneous blinking, startle responses, and (delay or trace) conditioning. We then establish the face validity of the model using simulated responses to unconditioned and conditioned stimuli to reproduce the sorts of behavior that are observed empirically. The scheme’s anatomical validity is then addressed by associating variables in the predictive coding scheme with nuclei and neuronal populations to match the (extrinsic and intrinsic) connectivity of the cerebellar (eyeblink conditioning) system. Finally, we try to establish predictive validity by reproducing selective failures of delay conditioning, trace conditioning, and extinction using (simulated and reversible) focal lesions. Although rather metaphorical, the ensuing scheme can account for a remarkable range of anatomical and neurophysiological aspects of cerebellar circuitry—and the specificity of lesion-deficit mappings that have been established experimentally. From a computational perspective, this work shows how conditioning or learning can be formulated in terms of minimizing variational free energy (or maximizing Bayesian model evidence) using exactly the same principles that underlie predictive coding in perception.

scholarly journals Cerebellar Cortex Contributions to the Expression and Timing of Conditioned Eyelid Responses

2010 ◽  
Vol 103 (4) ◽  
pp. 2039-2049 ◽  
Author(s):  
Brian E. Kalmbach ◽  
Tobin Davis ◽  
Tatsuya Ohyama ◽  
Frank Riusech ◽  
William L. Nores ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Cerebellar Cortex ◽  
Local Anesthetic ◽  
Eyelid Conditioning ◽  
Trace Conditioning ◽  
Anterior Lobe ◽  
Short Latency ◽  
Delay Conditioning ◽  
Conditioned Responses ◽  
Primary Fissure

We used micro-infusions during eyelid conditioning in rabbits to investigate the relative contributions of cerebellar cortex and the underlying deep nuclei (DCN) to the expression of cerebellar learning. These tests were conducted using two forms of cerebellum-dependent eyelid conditioning for which the relative roles of cerebellar cortex and DCN are controversial: delay conditioning, which is largely unaffected by forebrain lesions, and trace conditioning, which involves interactions between forebrain and cerebellum. For rabbits trained with delay conditioning, silencing cerebellar cortex by micro-infusions of the local anesthetic lidocaine unmasked stereotyped short-latency responses. This was also the case after extinction as observed previously with reversible blockade of cerebellar cortex output. Conversely, increasing cerebellar cortex activity by micro-infusions of the GABAA antagonist picrotoxin reversibly abolished conditioned responses. Effective cannula placements were clustered around the primary fissure and deeper in lobules hemispheric lobule IV (HIV) and hemispheric lobule V (HV) of anterior lobe. In well-trained trace conditioned rabbits, silencing this same area of cerebellar cortex or reversibly blocking cerebellar cortex output also unmasked short-latency responses. Because Purkinje cells are the sole output of cerebellar cortex, these results provide evidence that the expression of well-timed conditioned responses requires a well-timed decrease in the activity of Purkinje cells in anterior lobe. The parallels between results from delay and trace conditioning suggest similar contributions of plasticity in cerebellar cortex and DCN in both instances.

scholarly journals EMG activity in hyoid muscles during pig suckling

2012 ◽  
Vol 112 (9) ◽  
pp. 1512-1519 ◽  
Author(s):  
A. J. Thexton ◽  
A. W. Crompton ◽  
R. Z. German
Keyword(s):  
Emg Activity ◽  
Cycle Period ◽  
Second Phase ◽  
Cycle Duration ◽  
Fixed Duration ◽  
Cervical Plexus ◽  
Pharyngeal Swallow ◽  
Two Phases ◽  
Pharyngeal Swallowing ◽  
The Relationship

Infant suckling is a complex behavior that includes cycles of rhythmic sucking as well as intermittent swallows. This behavior has three cycle types: 1) suck cycles, when milk is obtained from the teat and moved posteriorly into the valleculae in the oropharynx; 2) suck-swallow cycles, which include both a rhythmic suck and a pharyngeal swallow, where milk is moved out of the valleculae, past the larynx, and into the esophagus; and 3) postswallow suck cycles, immediately following the suck-swallow cycles. Because muscles controlling these behaviors are active in all three types of cycles, we tested the hypothesis that different patterns of electromyographic (EMG) activity in the mylohyoid, hyoglossus, stylohyoid, and thyrohyoid muscles of the pig characterized each cycle type. Anterior mylohyoid EMG activity occurred regularly in every cycle and was used as a cycle marker. Thyrohyoid activity, indicating the pharyngeal swallow, was immediately preceded by increased stylohyoid and hyoglossus activity; it divided the suck-swallow cycle into two phases. Timed from the onset of the suck-swallow cycle, the first phase had a relatively fixed duration while the duration of the second phase, timed from the thyrohyoid, varied directly with cycle duration. In short-duration cycles, the second phase could have a zero duration so that thyrohyoid activity extended into the postswallow cycle. In such cycles, all swallowing activity that occurred after the thyrohyoid EMG and was associated with bolus passage through the pharynx fell into the postswallow cycle. These data suggest that while the activity of some muscles, innervated by trigeminal and cervical plexus nerves, may be time locked to the cycle onset in swallowing, the cycle period itself is not. The postswallow cycle consequently contains variable amounts of pharyngeal swallowing EMG activity. The results exemplify the complexity of the relationship between rhythmic sucking and the swallow.

scholarly journals Evidence that instrumental conditioning requires conscious awareness in humans

2020 ◽  
Author(s):  
Lina Skora ◽  
Martin Yeomans ◽  
Hans C. Crombag ◽  
Ryan Bradley Scott
Keyword(s):  
Instrumental Conditioning ◽  
Trace Conditioning ◽  
Adaptive Behaviour ◽  
Conscious Awareness ◽  
Backward Masking ◽  
Delay Conditioning ◽  
Complex Forms ◽  
Positive Stimuli ◽  
Monetary Reinforcement

Instrumental conditioning is a crucial substrate of adaptive behaviour, allowing individuals to selectively interact with the stimuli in their environment to maximise benefit and minimise harm. The extent to which complex forms of learning, such as instrumental conditioning, are possible without conscious awareness is a topic of considerable importance and ongoing debate. In light of recent theoretical and empirical contributions casting doubt on the early demonstrations of unconscious instrumental conditioning, we revisit the question of its feasibility in two modes of conditioning. In Experiment 1, we used trace conditioning, following a prominent paradigm (Pessiglione et al., 2008) and enhancing its sensitivity. Success in this task requires participants to learn to approach reward-predictive stimuli and avoid punishment-predictive stimuli through monetary reinforcement. All stimuli were rendered unconscious using forward-backward masking. In Experiment 2, we used delay conditioning to shorten the stimulus-outcome delay, retaining the structure of the original task but presenting the stimuli under continuous flash suppression to allow for an overlap of the stimulus, action, and outcome, as well as replacing monetary reinforcement with primary appetitive reinforcement. In both experiments, we found evidence for absence of unconscious instrumental conditioning, showing that participants were unable to learn to adjust their behaviour to approach positive stimuli and avoid negative ones. This result is consistent with evidence that unconscious stimuli fail to bring about long-term behavioural adaptations, and provides empirical evidence to support theoretical proposals that consciousness might be necessary for adaptive behaviour, where selective action is required.

How Fast is Fear?

2012 ◽  
Vol 26 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Ole Åsli ◽  
Magne Arve Flaten
Keyword(s):  
Conditioned Fear ◽  
Trace Conditioning ◽  
Automatic Processes ◽  
Unpaired Group ◽  
Time Intervals ◽  
Delay Conditioning ◽  
Trace Fear Conditioning ◽  
Minimum Latency ◽  
Fear Potentiated Startle ◽  
Trace Fear

The minimum latency of potentiated startle after delay and trace fear conditioning was investigated. Delay conditioning is hypothesized to be mediated by automatic processes, whereas trace conditioning is hypothesized to involve controlled cognitive processes. In a group receiving delay conditioning, a tone conditioned stimulus (CS) signaled an electric shock unconditioned stimulus (US) presented 1,000 ms after CS onset. In a group receiving trace conditioning, a 200 ms tone CS was followed by an 800 ms gap prior to US presentation. Two control groups received unpaired CS/US presentations. It was hypothesized that fear-potentiated startle should be observed at shorter time intervals after CS onset in the group receiving delay conditioning compared to the group receiving trace conditioning. The results showed increased startle at 100 and 150 ms after CS onset in the group receiving delay conditioning compared to the unpaired group. In the group receiving trace conditioning, increased startle was observed at 1,500 ms after CS onset compared to the unpaired group. This supports the idea that conditioned fear after delay conditioning may be due to automatic processes, whereas trace conditioning is dependent on controlled processes.

Adaptively Timed Learning

2021 ◽  
pp. 539-571
Author(s):  
Stephen Grossberg
Keyword(s):  
Memory Consolidation ◽  
Social Cognitive ◽  
Fragile X ◽  
Trace Conditioning ◽  
Incentive Motivation ◽  
Time Intervals ◽  
Delay Conditioning ◽  
Adaptive Timing ◽  
Causal Event ◽  
Dopamine Modulation

This chapter explains how humans and other animals learn to adaptively time their behaviors to match external environmental constraints. It hereby explains how nerve cells learn to bridge big time intervals of hundreds of milliseconds or even several seconds, and thereby associate events that are separated in time. This is accomplished by a spectrum of cells that each respond in overlapping time intervals and whose population response can bridge intervals much larger than any individual cell can. Such spectral timing occurs in circuits that include the lateral entorhinal cortex and hippocampal cortex. Trace conditioning, in which CS and US are separated in time, requires the hippocampus, whereas delay conditioning, in which they overlap, does not. The Weber law observed in trace conditioning naturally emerges from spectral timing dynamics, as later confirmed by data about hippocampal time cells. Hippocampal adaptive timing enables a cognitive-emotional resonance to be sustained long enough to become conscious of its feeling and its causal event, and to support BDNF-modulated memory consolidation. Spectral timing supports balanced exploratory and consummatory behaviors whereby restless exploration for immediate gratification is replaced by adaptively timed consummation. During expected disconfirmations of reward, orienting responses are inhibited until an adaptively timed response is released. Hippocampally-mediated incentive motivation supports timed responding via the cerebellum. mGluR regulates adaptive timing in hippocampus, cerebellum, and basal ganglia. Breakdowns of mGluR and dopamine modulation cause symptoms of autism and Fragile X syndrome. Inter-personal circular reactions enable social cognitive capabilities, including joint attention and imitation learning, to develop.

scholarly journals Muscimol-induced inactivation of the anterior cingulate cortex does not impair trace fear conditioning in the rat

2020 ◽  
Vol 34 (12) ◽  
pp. 1457-1460
Author(s):  
Marie A Pezze ◽  
Hayley J Marshall ◽  
Helen J Cassaday
Keyword(s):  
Anterior Cingulate Cortex ◽  
Fear Conditioning ◽  
Trace Conditioning ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Trace Interval ◽  
Noise Stimulus ◽  
Trace Fear Conditioning ◽  
Trace Fear

Previous studies suggest that trace conditioning depends on the anterior cingulate cortex (ACC). To examine the role of ACC in trace fear conditioning further, 48 rats were surgically prepared for infusion with saline or 62.5 or 125 µg/side muscimol to inactivate ACC reversibly prior to conditioning. A noise stimulus was followed by a 1 mA footshock, with or without a 10-second trace interval between these events in a conditioned suppression procedure. The trace-conditioned groups (10 seconds) showed less test suppression than the control-conditioned groups (0 seconds). Counter to prediction, there was no effect of muscimol infusion on suppression to the noise stimulus in the 10-second trace groups.

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