Arwas S, Rolnick A, Lubow RE (1989) Conditioned taste aversion in humans using motion-induced sickness as the US. Behav Res Ther 27: 295-301

gif Study on Israeli Navy recruits who volunteered. Coca Cola/ Sprite versus Scheppes Tonic or ginger ale. A special chair was used to induce motion sickness.

(3/20 ill; 9/20 asked to stop but 9/20 little sign of motion sickness)

test was 2hrs after the motion, when symptoms were absent

Abstract follows

  • The purpose of the experiment was to demonstrate conditioned taste aversion (CTA) and latent inhibition (LI) of CTA in humans using rotation-induced motion sickness as the unconditioned stimulus.

  • To accomplish this, flavour familiarity (familiar vs unfamiliar) and rotation (rotation vs no rotation) were manipulated in a 2 X 2 factorial design.

  • Subjects consumed either a familiarly flavoured carbonated beverage or a novel one after which half of each group was rotated or not rotated.

  • Two hours later the subjects were re-presented with the flavoured drink that they had previously drunk.

  • The groups receiving rotation consumed less of the drink that the non-rotated groups, thus demonstrating CTA.

  • The rotated group pre-exposed to the novel flavoured drink consumed less than the rotated group pre-exposed to the familiar drink, thus demonstrating LI.

  • The effectiveness of the rotation procedure in producing motion sickness was confirmed by self-reports of general feelings and by symptom rating scales.

  • In addition, it was found that, at the time of consuming the test drink the rotation groups' motion-sickness symptom scores were reduced to the level of the nonrotated groups.

  • Applications of these data to the prophylactic treatment of chemotherapy-induced food aversions were discussed.

 

Hu S, Willoughby LM, Lagomarsino JJ, Jaeger HA (1996) Optokinetic rotation- induced taste aversions correlate with over-all symptoms of motion sickness in humans. Percept Mot Skills 82: 859-864

  • 51 subjects were divided into Familiar- and Unfamiliar-drink groups based on whether they had tasted soybean milk before the experiment.

  • Each subject then viewed an optokinetic rotating drum for 10 min.

  • Subjective assessments of nausea and over-all symptoms of motion sickness were measured during the drum rotation.

  • Two hours later subjects drank the soybean milk again.

  • The consumed volume and rating of likeableness of the drink were subsequently measured.

  • Analysis showed that the subjects in the Unfamiliar-drink group reported significantly higher taste aversion and consumed significantly less soybean milk after rotation than those in the Familiar-drink group.

  • Correlation for the Unfamiliar-drink group indicated that the rated taste aversion was positively correlated with ratings of over-all symptoms of motion sickness and that the consumed volume of soybean milk was negatively correlated with ratings of over-all symptoms of motion sickness.

  • We concluded that the magnitude of acquired conditioned taste aversion was dependent upon the severity of over-all symptoms of visually induced motion sickness when subjects were unfamiliar with the flavor of the target drink.

Green, J.T. and Woodruff-Pak, D.S. (2000) Eyeblink classical conditioning: Hippocampal formation is for neutral stimulus associations as cerebellum is for association- response. Psychological Bulletin, 126, 138-158.

Extensive evidence has been amassed that the cerebellum, hippocampus, and associated circuitry are activated during classical conditioning of the nictitating membrane/eyeblink response. In this article, the authors argue that the cerebellum is essential to all eyeblink classical conditioning paradigms. In addition, the septohippocampal system plays a critical role when the classical conditioning paradigm requires the formation of associations in addition to the simple association between the conditioned and unconditioned stimuli. When only a simple conditioned stimulus-unconditioned stimulus association is needed, the septohippocampal system has a more limited, modulatory role. The neutral stimulus association versus simple association-response distinction is one of the ways in which declarative or relational memory can be separated from nondeclarative or nonrerelational memory in classical conditioning paradigms.

Morris, J.S., Ohman, A. and Dolan, R.J. (1998) Conscious and unconscious emotional learning in the human amygdala. Nature, 393, 467-470.

If subjects are shown an angry face as a target visual stimulus for less than forty milliseconds and are then immediately shown an expressionless mask, these subjects report seeing the mask but not the target. However, an aversively conditioned masked target can elicit an emotional response from subjects without being consciously perceived(1,2). Here we study the mechanism of this unconsciously mediated emotional learning. We measured neural activity in volunteer subjects who were presented with two angry faces, one of which, through previous classical conditioning, was associated with a burst of white noise. In half of the trials, the subjects' awareness of the angry faces was prevented by backward masking with a neutral face. A significant neural response was elicited in the right, but not left, amygdala to masked presentations of the conditioned angry face. Unmasked presentations of the same face produced enhanced neural activity in the left, but not right, amygdala. Our results indicate that, first, the human amygdala can discriminate between stimuli solely on the basis of their acquired behavioural significance, and second, this response is lateralized according to the subjects' level of awareness of the stimuli.

Stares, K., Kemenes, G. and Benjamin, P.R. (1999) Cellular traces of behavioral classical conditioning can be recorded at several specific sites in a simple nervous system. Journal of Neuroscience, 19, 347-357.

We used a behavioral learning paradigm followed by electrophysiological analysis to find sites in the Lymnaea feeding network in which electrical changes could be recorded after appetitive conditioning. Specifically we analyzed conditioning-induced changes in cellular responses in the mechanosensory conditioned stimulus (CS) pathway, in the central pattern generator (CPG) network, and in feeding motoneurons. During training, experimental animals received 15 pairings of lip touch (the CS) with sucrose (the unconditioned stimulus, US). Control animals received 15 random CS and US presentations. Electrophysiological tests on semi-intact preparations made from conditioned animals demonstrated a network correlate of the overall feeding conditioned response, a touch-evoked CPG-driven fictive feeding rhythm. At the motoneuronal level, we found significant conditioning-induced increases in the amplitude of an early touch-evoked EPSP and spike activity, recorded from the B3 feeding motoneuron. Increases in EPSP amplitude and motoneuronal spike activity could occur independently of conditioned fictive feeding. These changes in response recorded at the level of CPG interneurons, and motoneurons were preceded by changes recorded in the CS pathway. This was demonstrated by recording a conditioning- induced increase in the number of touch-evoked spikes in the cerebrobuccal connective, which forms part of the CS pathway. The finding that electrophysiological changes after conditioning can be recorded at multiple sites in this simple system provided an important intermediate level of analysis between whole animal behavior and cellular studies on the synaptic sites of plasticity.

Till, B.D. and Priluck, R.L. (2000) Stimulus generalization in classical conditioning: An initial investigation and extension. Psychology & Marketing, 17, 55- 72.

Conditioning as a mechanism for attitude change has received much attention over the past 10 years. This research examines stimulus generalization, the extent to which a response conditioned to one stimulus transfers to similar stimuli. Stimulus generalization relates to both brand extension and private-label imitations of national brands. Two studies collectively provide evidence that attitudes which are conditioned to a particular brand Can be transferred to a product with a similar name in the same category, as well as a product with the same name in a different category. Study Two suggests that stimulus generalization effects may be relatively transitory. (C) 2000 John Wiley & Sons, Inc.

Timmann, D., Baier, C., Diener, H.C. and Kolb, F.P. (1998) Impaired acquisition of limb flexion reflex and eyeblink classical conditioning in a cerebellar patient. Neurocase, 4, 207-217.

  • In the present study, we investigated classical conditioning of both the limb flexion reflex as well as the eyeblink reflex in a patient with a circumscribed lesion of the left intermediate cerebellum also affecting parts of the upper vermis.

  • The lesion affected predominantly the cerebellar cortex,

  • Classical conditioning of the limb flexion reflex and eyeblink response was impaired on the affected, left side,

  • On the right side, limb flexion conditioning was not impaired and eyeblink conditioning was within the lower range of normal,

  • These findings show that the intermediate cerebellum is critically involved in classical conditioning of both the limb flexion reflex as well as the eyeblink response in man,

  • Limb flexion reflex responses were significantly larger on the affected side compared to the unaffected side in unconditioned stimulus-alone trials.

  • These findings agree with results from animal studies where increased unconditioned response amplitudes of the eyeblink reflex following cerebellar cortical lesions were reported.

(see also

Dimitrova, A., Kolb, F. P., Elles, H.-G., Maschke, M., Gerwig, M., Gizewski, E., & Timmann, D. Cerebellar activation during leg withdrawal reflex conditioning: an fMRI study. Clinical Neurophysiology, in press)