ALG Christmas Workshop 2012

Transcription

1 ALG Christmas Workshop When: Friday 7th December Where: New Law Seminar 100, Eastern Avenue,. (To get to Seminar Room 100, enter the New Law Annex from Eastern Avenue and go down the short flight of stairs. Seminar Room 100 is just ahead on the right side of the hall.) Organiser: Anna Thorwart 9:30 Flavour conditioning can produce short-term satiety Michael Kendig & Bob Boakes 9:50 Superconditioning of a flavour preference Bob Boakes & Dorothy Kwok 10:10 Plasticity within the prelimbic-dorsomedial striatum pathway underlies the acquisition of goal-directed actions Genevra Hart & Bernard Balleine / 10:30 Evaluating the medial orbital frontal cortex: a risky business? Laura Bradfield & Bernard Balleine 10:50 Extinction and non-reinforcement Justin Harris 11:10 COFFEE BREAK 11:30 Impairing goal-directed control in normal people by secondary tasks Lee Hogarth 11:50 Learned Predictability: Prior predictability biases competition amongst outcomes Anna Bethmont, Oren Griffiths, Peter Lovibond & Chris Mitchell, University of Plymouth 12:10 An experimental manipulation of contingency awareness to investigate the effects on differential delay eyeblink conditioning. Gabrielle Weidemann, Peter Lovibond & Michelle Satkunarajah UWS,

2 12:30 Action-based decision making in the human brain RW Morris, A Dezfouli, K Griffiths & B Balleine 12:50 Can EEG frequency, amplitude, and phase reflect concomitant changes in associative learning in the assessment of conditioned inhibition? Kathryn Anderson & Jillene Harris Charles Sturt University 13:10 LUNCH BREAK 14:10 Observational learning of learned helplessness in humans. Ian Johnston 14:30 Pavlovian facilitation of appetitive instrumental responding in humans using a natural reward Peter Lovibond & Ben Colagiuri, 14:50 Extinction of reinstated or ABC renewed fear responses renders them resistant to ABA renewal Nathan Holmes 15:10 Basolateral amygdala is necessary for encoding but not for retrieving outcome value to guide choice Shauna Parkes & Bernard Balleine 15:30 Delta-opioid receptor plasticity in the nucleus accumbens shell is necessary but not sufficient for specific Pavlovian-instrumental transfer Ash Morse & Bernard Balleine / 15:50 COFFEE BREAK 16:10 The effects of high fat and sugar diets on cognition in the rat Jessica E Beilharz, Jayanthi Maniam, Margaret J Morris, & R Fred Westbrook 16:30 The Rodent Lateral Orbitofrontal Cortex is Necessary for Between but not Within Session Pavlovian Extinction Marios Panayi & Simon Killcross 16:50 Behavioural measure of uncertainty in a sensory decision paradigm Justine Fam, Fred Westbrook, Ehsan Arabzadeh 17:10 Making memories malleable - Dopaminergic prediction-error signalling underpins memory reconsolidation Amy Reichelt 17:30 DRINKS AND DINNER

3 Abstracts Flavour conditioning can produce short-term satiety Michael Kendig & Bob Boakes Learning about the post-ingestive effects of flavours can have important implications for long-term regulation of energy intake and body weight. We investigated whether exposure to a flavour previously associated with a high nutrient load would reduce subsequent chow consumption relative to a flavour previously paired with a low nutrient load, using a calorie compensation test. Thus, rats were first administered discrimination training involving intermixed pairings of one flavour added to a high-calorie solution (High flavour) and a second flavour added to a low-calorie solution (Low flavour). On one test day rats were given a pre-meal to which the High flavour was added, and on a separate day the test was repeated with the Low flavour added (order counterbalanced). The pre-meals were each followed by free access to chow, with intake measured at 15, 30 and 60 minutes. Experiment 1 used yoghurt for the pre-meal and found that rats reduced their intake of chow at 15 and 30, but not 60 min, when the high-calorie flavour was added to the yoghurt. This conditioned compensation effect did not vary according to whether a carbohydrate- or protein-based nutrient was used during conditioning training. Experiment 2 used a liquid pre-meal and replicated this result, but only when Almond essence was used as the CS+. Superconditioning of a flavour preference Bob Boakes & Dorothy Kwok During an initial training stage, good days, in which rats are given 20% maltodextrin, are intermixed with bad days, in which they are given 3% maltodextrin flavoured with almond. In a subsequent 2-bottle test rats given such intermixed training show more avoidance of almond than control rats given blocked training, a phenomenon we have labelled the missing calorie effect. To the extent that almond has inhibitory properties, it should support superconditioning of a second flavour. We report two experiments that confirmed this prediction. Both started with the training described above and followed with a single conditioning session in which both almond and 0.2% NaCl (saline) were added to 10% maltodextrin solution. In a subsequent 2-bottle test superconditioning of a saline preference was obtained, in that rats with Intermixed training showed a stronger preference than controls given Blocked training. Plasticity within the prelimbic-dorsomedial striatum pathway underlies the acquisition of goal-directed actions Genevra Hart & Bernard Balleine /

4 Evaluating the medial orbital frontal cortex: a risky business? Laura Bradfield & Bernard Balleine Extinction and non-reinforcement Justin Harris More of the same Impairing goal-directed control in normal people by secondary tasks Lee Hogarth The balance between goal-directed and habitual control over reward-seeking is thought to be flawed in a number of psychiatric conditions including drug addiction and schizophrenia. Consequently, a laboratory procedure capable of demonstrating impaired goal-directed control in normal people may be useful for modelling this abnormality in clinical populations. This talk will describe human outcome-devaluation studies which have included various distractor tasks at training and test. These studies suggest that goal-directed control over reward-seeking is impaired by the concurrent requirement to evaluate the appetitive value of similar reinforcers at test, but is not affected by the evaluation of unrelated reinforcers, or by standard working memory loads. It is concluded that goal-directed choice relies on the sequential, domain specific retrieval of prospects. This process may be impaired in psychiatric conditions. Learned Predictability: Prior predictability biases competition amongst outcomes Anna Bethmont, Oren Griffiths, Peter Lovibond & Chris Mitchell, University of Plymouth Many studies of human associative learning have demonstrated competition amongst concurrently presented cues, but few have examined analogous competition effects amongst outcomes. Three experiments examined the role of outcome competition in a cue-outcome predictive learning task. More specifically, the experiments investigated whether outcomes whose occurrence is predictable in an initial phase of training are better learned about in a second phase, than outcomes that were formerly unpredictable. This effect can be considered analogous to the learned predictiveness effect observed in competition between cues (Le Pelley & McLaren, 2003). The experiments also investigated the contribution of attentional processes in this competition effect by measuring eye-gaze throughout. Formerly predictable outcomes were learned about more rapidly than formerly unpredictable outcomes. However, this effect critically depended upon the predictive status of the cue used to probe the cue-

5 outcome relationship, and is therefore not straightforwardly accommodated in any existing model of associative learning. An experimental manipulation of contingency awareness to investigate the effects on differential delay eyeblink conditioning. Gabrielle Weidemann, Peter Lovibond & Michelle Satkunarajah UWS, There is considerable controversy about whether differential delay eyeblink conditioning can occur in the absence of contingency awareness. Most previous experiments which have investigated the relationship between contingency awareness and eyeblink conditioning have relied on a post-hoc assessment of contingency awareness. The experiment that I am going to talk about today instead manipulated participants contingency awareness experimentally. Initially all participants were asked to carry out two alternating tasks, one which involved the unconditioned stimulus (US; an airpuff to the eye) and the second which involved the conditioned stimuli (CSs; coloured geometric shapes). Two groups were informed that there was a relationship between the two tasks. One group were told which CS predicted the US, Group Informed, and the second group were told that the two tasks were related but not which CS predicted the US, Group Related. Two other groups were not informed of the relationship. For one of these groups there was a reliable relationship between the CS and the US, Group Uninformed, and for the second group there was no reliable relationship between the CS and the US but the US occurred with the same temporal distribution as in the other three groups, Group Pseudo. The pattern of differential eyeblink responses varied as a function of the group, with Group Informed showing the greatest differentiation and Groups Pseudo and Uninformed showing the least. Action-based decision making in the human brain RW Morris, A Dezfouli, K Griffiths & B Balleine Can EEG frequency, amplitude, and phase reflect concomitant changes in associative learning in the assessment of conditioned inhibition? Kathryn Anderson Charles Sturt University As part of a project to investigate the role of expectancy in appetitive motivation, we carried out two appetitive Pavlovian-instrumental transfer studies in human participants using a chocolate reward. After VR10 instrumental training with a single button-press response, and differential Pavlovian conditioning with two coloured lights, we tested the effect of the Pavlovian stimuli on instrumental responding. Following convention, the test phase was conducted under both Pavlovian and instrumental extinction. In Study 1 the CSs were 10 sec long. Presentation of CS+ but not CS- led to enhanced instrumental

6 responding that commenced in the second half of the CS and lasted approximately 30 sec. A similar pattern was observed in Study 2, in which the Pavlovian CSs were 30 sec long, suggesting that the increased responding was not due to frustration arising from the non-occurrence of reward signalled by CS+. We raise for discussion the question of whether this enhancement of goal-directed behaviour is motivational in nature, and whether it depends on reward expectancy. Observational learning of learned helplessness in humans. Ian Johnston The learned helplessness effect is a widely observed phenomenon in which animals or people show deficits in learning, motivation and an aversive emotional state after they have experienced a stressful situation they cannot control. In humans, this can be replicated experimentally by giving subjects problems to solve in which the solution is impossible to attain. Here, I will describe some experiments in which subjects were asked to pair-up. One person was asked to solve a set of anagrams, one person was asked to test the other person. Three groups were tested: A group in which the anagrams were of common English words, a group in which the anagrams were of extremely rare English words (and so were unlikely to be solved), and a group that was asked to simply read the easy set of anagrams. Following this task, the subjects were then asked to do other word puzzles. In Experiment 1, it was a another set of anagrams, and in Experiment 2 it was a target puzzle. The results showed that not only did the people who attempted the impossible anagrams show deficits in the later tasks compared to the other two controls, but the people who tested them with the impossible showed similar deficits. These results suggest that the learned helplessness effect can be acquired through observational learning, and not solely with direct experience with an impossible task. Pavlovian facilitation of appetitive instrumental responding in humans using a natural reward Peter Lovibond & Ben Colagiuri, As part of a project to investigate the role of expectancy in appetitive motivation, we carried out two appetitive Pavlovian-instrumental transfer studies in human participants using a chocolate reward. After VR10 instrumental training with a single button-press response, and differential Pavlovian conditioning with two coloured lights, we tested the effect of the Pavlovian stimuli on instrumental responding. Following convention, the test phase was conducted under both Pavlovian and instrumental extinction. In Study 1 the CSs were 10 sec long. Presentation of CS+ but not CS- led to enhanced instrumental responding that commenced in the second half of the CS and lasted approximately 30 sec. A similar pattern was observed in Study 2, in which the Pavlovian CSs were 30 sec

7 long, suggesting that the increased responding was not due to frustration arising from the non-occurrence of reward signalled by CS+. We raise for discussion the question of whether this enhancement of goal-directed behaviour is motivational in nature, and whether it depends on reward expectancy. Extinction of reinstated or ABC renewed fear responses renders them resistant to ABA renewal Nathan Holmes Basolateral amygdala is necessary for encoding but not for retrieving outcome value to guide choice Shauna Parkes & Bernard Balleine Delta-opioid receptor plasticity in the nucleus accumbens shell is necessary but not sufficient for specific Pavlovian-instrumental transfer Ash Morse & Bernard Balleine / The effects of high fat and sugar diets on cognition in the rat Jessica E Beilharz, Jayanthi Maniam, Margaret J Morris, & R Fred Westbrook Long-term exposure to a diet rich in both saturated fat and simple sugars is associated with cognitive impairments in both humans and rodents. The present study used rats to examine whether short term exposure to such a diet also impaired cognition. In Experiment 1, rats were impaired on place, but not object recognition memory when tested after five, 11 and 20 days of exposure to a cafeteria style diet supplemented with a 10% sucrose solution. In Experiment 2, rats were also impaired at these time points on the hippocampal-dependent place, but not the perirhinal-dependent object task after exposure to the cafeteria diet plus a 10% sucrose solution, a regular diet supplemented with a 10% sucrose solution or to a cafeteria diet without sucrose. Levels of hippocampal tumor necrosis factor (TNFα) were elevated in rats fed these diets and negatively correlated with place recognition memory. These results show that relatively short exposures to diets rich in fat and sugar or rich in sugar impair hippocampal-dependent recognition memory prior to the emergence of weight differences, and suggest a role for neuroinflammation in this impairment.

8 The Rodent Lateral Orbitofrontal Cortex is Necessary for Between but not Within Session Pavlovian Extinction Marios Panayi & Simon Killcross Objective: Extinction learning in Pavlovian learning tasks depends upon a number of neural regions e.g. the amygdala. The orbitofrontal cortex (OFC) is a cortical structure that is functionally connected to subregions of the amygdala, yet its role in extinction learning has not been directly assessed. OFC lesions impair performance on reversal learning tasks, which require the simultaneous acquisition of new and the extinction of old, cue-outcome associations. Thus there is good evidence to suggest that the OFC plays a role in extinction. The present study directly assessed the role of the OFC in Pavlovian extinction. Methods: Long Evans rats received 16 presentations of a 15s click stimulus followed by a pellet reward per day for 9 sessions. Cannulae were then surgically implanted targeting the lateral OFC. After 3 more days of acquisition, all animals received 3 days of extinction with an infusion of muscimol (n = 7) or saline (n = 8), followed by 3 days of extinction with no infusions. Extinction sessions were identical to acquisition except that no pellets were delivered. Response frequency at the site of pellet delivery was measured. Results: Over the first 3 infusion days saline control animals appropriately decreased responding between and within each session. In contrast, muscimol infused animals appropriately reduced responding within each session, but returned to a high level of responding at the start of each day. In the absence of drug infusions, animals that had previously received muscimol showed an appropriate reduction in responding between days. Conclusions: Functional inactivation of the rodent lateral OFC selectively impaired between but not within session extinction. The possible role of the OFC in consolidation and/or the representation of context will be discussed. Acknowledgements: This study was funded by ARC Discovery Grant DP and ARC Discovery Grant DP Behavioural measure of uncertainty in a sensory decision paradigm Justine Fam, Fred Westbrook, Ehsan Arabzadeh Making memories malleable - Dopaminergic prediction-error signalling underpins memory reconsolidation Amy Reichelt Memory reconsolidation is proposed to be a mechanism by which memories are updated to maintain their relevance. The retrieval of memories can lead to their destabilisation, requiring a restabilisation process that is known as reconsolidation. The plasticity

9 involved in reconsolidation may thus enable the integration of updating information. However, retrieval does not always lead to memory destabilization, under specific behavioural conditions we demonstrate that the systemic injection of the NMDA receptor antagonist MK-801 before memory retrieval impaired subsequent conditioned approach behaviour to a stimulus previously associated with sucrose. This demonstration that the memories underlying pavlovian goal-tracking undergo reconsolidation is of particular interest because it draws a link to the potential role of prediction error signals in regulating memory reconsolidation. In a pavlovian conditioned approach setting, memory reconsolidation is disrupted by systemic injections of the NMDA receptor antagonist MK-801. Moreover, in a similar setting, prediction error signaling is critically dependent upon ventral tegmental area (VTA) dopaminergic activity (Takahashi et al., 2009). Therefore, we tested the hypothesis that dysregulation of VTA dopaminergic signalling would impair the putative prediction error signal induced by memory retrieval to prevent goal-tracking memories from being destabilised. As a result, those memories would be resistant to the amnestic effect of MK-801. Here we demonstrate that dysregulation of VTA dopaminergic signalling by infusion of the GABA agonists (muscimol/baclofen) or the dopamine D2 antagonist sulpiride impaired prediction error signal induced by memory retrieval, inhibiting goal-tracking memories from being destabilised and thus prevented the amnestic effect of MK-801