6. References Amiro TW, Bitterman ME (1980) Second-order appetitive conditioning in goldfish. J. Exp. Psychol. Anim. Behav. Process. 6:41-48. Bakal CW, Johnson RD, Rescorla RA (1974) The effect of change in US quality on the blocking effect. Pavlov J. Biol. Sci. 9:97-103. Balleine B (1994) Asymmetrical interactions between thirst and hunger in Pavlovian-instrumental transfer. Q. J. Exp. Psychol. B. 47:211-231. Barnet RC, Grahame NJ, Miller RR (1993) Temporal encoding as a determinant of blocking. J. Exp. Psychol. Anim. Behav. Process. 19:327-341. Batsell WR (1997) Retention of context blocking in taste-aversion learning. Physiol. Behav. 61:437-446 . Bitterman ME (1996) Comparative analysis of learning in honeybees. Anim. Learn. Behav. 24:123-141. Brembs B (1996) Classical and Operant Conditioning in Drosophila at the Flight Simulator. Diplomarbeit. Würzburg: Julius-Maximilians-Universität. http://brembs.net/diploma Brogden JW (1939) Unconditional stimulus-substitution in the conditioning process. Am. J. Psychol. 52:46-55. Carew TJ, Sahley CL (1986) Invertebrate learning and memory: from behavior to molecules. Annu Rev Neurosci. 9:435-487. Cheatle MD, Rudy JW (1978) Analysis of second-order odor-aversion conditioning in neonatal rats: implications for Kamin's blocking effect. J. Exp. Psychol. Anim. Behav. Process. 4:237-249. Couvillon PA, Bitterman ME (1980) Some phenomena of associative learning in honey bees. J. Comp. Physiol. Psychol. 94:878-885. Couvillon PA, Bitterman ME (1982) Compound conditioning in honey bees. J. Comp. Physiol. Psychol. 96:192-199. Couvillon PA, Bitterman ME (1989) Reciprocal overshadowing in the discrimination of color-odor compounds by honeybees further tests of a continuity model. Anim. Learn. Behav. 17:213-222. Couvillon PA, Mateo E-T, Bitterman ME (1996) Reward and learning in honeybees: Analysis of an overshadowing effect. Anim. Learn. Behav. 24:19-27. Couvillon PA, Arakaki, L., Bitterman, M.E, (1997) Intramodal blocking in honeybees. Anim. Learn. Behav. 25:277-282. Denniston JC, Miller RR, Matute H (1996) Biological significance as determinant of cue competition. Psych. Sci. 7:325-331. Dill M, Heisenberg M (1995) Visual pattern memory without shape recognition. Phil. Trans. R. Soc. Lond. B Biol. Sci. 349:143-152. Dill M, Wolf R, Heisenberg M (1993) Visual pattern recognition in Drosophila involves retinotopic matching. Nature. 365:751-753. Dill M, Wolf R, Heisenberg M (1995) Behavioral analysis of Drosophila landmark learning in the flight simulator. Learn. & Mem. 2:152-160. Donahoe JW (1997) Selection networks: Simulation of plasticity through reinforcement learning. In: Neural-Networks models of cognition (Donahow JW, Packard-Dorsel V ed): Elsevier Science B. V. Donahoe JW, Burgos JE, Palmer DC (1993) A selectionist approach to reinforcement. J. Exp. Anal. Behav. 60:17-40. Donahoe JW, Palmer DC, Burgos JE (1997) The S-R issue: Its status in behavior analysis and in Donhaoe and Palmer's "Learning and Complex Behavior" (with commentaries and reply). J. Exp. Anal. Behav. 67:193-273. Dukas R (1999) Costs of Memory: Ideas and Predictions. J. theor. Biol. 197:41-50. Ernst R, Heisenberg M (1999) The memory template in Drosophila pattern vision at the flight simulator. Vision Research 39:3920-3933. Eyding D (1993) Lernen und Kurzzeitgedächtnis beim operanten Konditionieren auf visuelle Muster bei strukturellen und bei chemischen Lernmutanten von Drosophila melanogaster. Diplomarbeit. Würzburg: Julius-Maximilians-Universität. Fanselow MS (1998) Pavlovian conditioning, negative feedback, and blocking: mechanisms that regulate association formation. Neuron 20:625-627. Farley J, Reasoner H, Janssen M (1997) Potentiation of phototactic suppression in Hermissenda by a chemosensory stimulus during compound conditioning. Behav. Neurosci 111:320-341. Feldman JM (1971) Added cue control as a function of reinforcement predictability. J. exp. Psychol. 91:318-325. Feldman JM (1975) Blocking as a function of added cue intensity. Anim. Learn. Behav. 3:98-102. Gerber B, Ullrich J (1999) No evidence for olfactory blocking in honeybee classical conditioning. J. Exp. Biol. 202:1839-1854. Glanzman DL (1995) The cellular basis of classical conditioning in Aplysia californica - it's less simple than you think. Trends Neurosci. 18:30-36. Gormezano I, Tait RW (1976) The Pavlovian analysis of instrumental conditioning. Pavlov. J. Biol. Sci. 11:37-55. Götz KG (1964) Optomotorische Untersuchung des visuellen Systems einiger Augenmutanten der Fruchtfliege Drosophila. Kybernetik. 2:77-92. Grant DA, Kroll NE, Kantowitz B, Zajano MJ, Solberg KB (1969) Transfer of eyelid conditioning from instrumental to classical reinforcement and vice versa. J. Exp. Psychol. 82:503-510. Guo A, Götz KG (1997) Association of visual objects and olfactory cues in Drosophila. Learn. & Mem. 4:192-204. Guo A, Liu L, Xia SZ, Feng CH, Wolf R, Heisenberg M (1996) Conditioned visual flight orientation in Drosophila; Dependence on age, practice and diet. Leran. & Mem. 3:49-59. Guthrie ER (1952) The Psychology of Learning. New York: Harper. Haddad NF, Walkenbach J, Preston M, Strong R (1981) Stimulus control in a simple instrumental task the role of internal and external stimuli. Learn. Motiv. 12:509-520. Hall D, Suboski MD (1995) Sensory Preconditioning and Second-Order Conditioning of alarm Reactions in Zebra Danio Fish (Brachydanio rerio). J. Comp. Psychol. 109:76-84. Hall G (1996) Learning about associatively activated stimulus representations: Implications for acquired equivalence and perceptual learning. Anim. Learn. Behav. 24:233-255. Hammer M (1993) An identified neuron mediates the unconditioned stimulus in associative learning in honeybees. Nature. 366:59-63. Hammer M (1997) The neural basis of associative reward learning in honeybees. Trends. Neurosci. 20:245-252. Hammerl M (1993) Blocking observed in human instrumental conditioning. Learn. Motiv. 24:73-87. Hawkins RD, Abrams TW, Carew TJ, Kandel ER (1983) A cellular mechanism of classical conditioning in Aplysia: activity-dependent amplification of presynaptic facilitation. Science. 219:400-405. Hawkins RD, Greene W, Kandel ED (1998) Classical conditioning, differential conditioning, and second-order conditioning of the Aplysia gill-withdrawal reflex in a simplified mantle organ preparation. Behav. Neurosci. 112:636-645. Hebb DO (1956) The distinction between "classical" and "instrumental.". Can. J. Psychol. 10:165-166. Heisenberg M (1983) Initiale Aktivitat und Willkürverhalten bei Tieren. Naturwissenschaften. :70-78. Heisenberg M (1994) Voluntariness (Willkürfahigkeit) and the general organization of behavior. L. Sci. Res. Rep. 55:147-156. Heisenberg M, Wolf R (1984) Vision in Drosophila.Genetics of Microbehavior. Berlin, Heidelberg, New York, Tokio: Springer. Heisenberg M, Wolf R (1988) Reafferent control of optomotor yaw torque in drosophila-melanogaster. J. Comp. Physiol. A Sens. Neural. Behav. Physiol. 163:373-388. Heisenberg M, Wolf R (1993) The sensory-motor link in motion-dependent flight control of flies. Rev. Oculomot. Res. 5:265-283. Hellige JB, Grant DA (1974) Eyelid conditioning performance when the mode of reinforcement is changed from classical to instrumental avoidance and vice versa. J. Exp. Psychol. 102:710-719. Hoffmann J (1993) Vorhersage und Erkenntnis. Die Funktion von Antizipationen in der menschlichen Verhaltenssteuerung und Wahrnehmung. Göttingen, Bern, Toronto, Seattle: Hogrefe. Holland PC (1997) Brain mechanisms for changes in processing of conditioned stimuli in Pavlovian conditioning: Implications for behavior theory. Anim. Learn. Behav. 25:373-399. Holland PC, Gallagher M (1993) Effects of amygdala central nucleus lesions on blocking and unblocking. Behav.Neurosci. 107:235-245. Holland PC, Rescorla RA (1975a) The effect of two ways of devaluing the unconditioned stimulus after first and second-order appetitive conditioning. J. Exp. Psychol. Anim. Behav. Process. 104 :355-363. Holland PC, Rescorla RA (1975b) Second-order conditioning with food unconditioned stimulus. J Comp Physiol Psychol. 88:459-467. Holman JG, Mackintosh NJ (1981) The control of appetitive instrumental responding does not depend on classical conditioning of the discriminative stimulus. Q. J. exp. Psychol. 33B:21-31. Horridge GA (1962) Learning of leg position by headless insects. Nature 193:697-698. Hoyle G (1979) Mechanisms of simple motor learning. Trends. Neurosci. 2:153-155. Hull CL (1929) A functional interpretation of the conditioned reflex. Psych. Rev. 36:498-511. Jones SH, Gray JA, Hemsley DR (1990) The Kamin blocking effect, incidental learning and psychoticism. Br. J. Psychol. 81:95-109. Kamin LJ (1968) Attention- like processes in classical conditioning. In: Miami symposion on predictability, behavior and aversive stimulation (Jones MR, ed), pp 9-32. Miami: Miami University Press. Kamin LJ (1969) Predictability, surprise, attention, and conditioning. In: Punishment and aversive behavior (Church RM, ed), pp 279-296. New York: Appleton-Century-Crofts. Kandel ER, Abrams T, Bernier L, Carew TJ, Hawkins RD, Schwartz JH (1983) Classical conditioning and sensitization share aspects of the same molecular cascade in Aplysia. Cold Spring Harb. Symp. Quant. Biol. 48:821-830. Kim JJ, Krupa DJ, Thompson RF (1998) Inhibitory cerebello-olivary projections and blocking effect in classical conditioning. Science 279:570-573. Kimmel HD (1977) Notes from "Pavlov's Wednesdays": sensory preconditioning. Am. J. Psychol. 90:319-321. Kimmel HD, Bevill MJ (1991) Blocking and unconditioned response diminution in human classical autonomic conditioning. Integr. Physiol. Behav. Sci. 26:132-138. Kimmel HD, Bevill MJ (1996) Blocking and unconditioned response diminution in human classical autonomic conditioning. Integr. Physiol. Behav. Sci. 31:18-43. Kojima S, Kobayashi S, Yamanaka M, Sadamoto H, Nakamura H, Fujito Y, Kawai R, Sakakibara M, Ito E (1998) Sensory preconditioning for feeding response in the pond snail, Lymnaea stagnalis. Brain Res. 808:113-115. Konorski J, Miller S (1937a) On two types of conditioned reflex. J. Gen. Psychol. 16:264-272. Konorski J, Miller S (1937b) Further remarks on two types of conditioned reflex. J. Gen. Psychol. 17:405-407. Lattal KM, Nakajima S (1998) Overexpectation in appetitive Pavlovian and instrumental conditioning. Anim. learn. Behav. 26:351-360. Levey AB, Martin I (1991) Human classical conditioning. The status of the CS. Integr. Physiol. Behav. Sci. 26:26-31. Liu L, Wolf R, Ernst R, Heisenberg M (1999) Context generalization in Drosophila visual learning requires the mushroom bodies. Nature 400:753-756. Lyn SA, Capaldi ED (1994) Robust conditioned flavor preferences with a sensory preconditioning procedure. Psychon. Bull. Rev. 1:491-493. Mackintosh NJ (1975a) Blocking of conditioned suppression: role of the first compound trial. J. Exp. Psychol. Anim. Behav. Process. 1:335-345. Mackintosh NJ (1975b) A theory of attention: Variations in the associability of stimuli with reinforcement. Psychol. Rev. 82:276-298. Mackintosh NJ (1976) Overshadowing and stimulus intensity. Anim. Learn. Behav. 4:186-192. Marchant HG, Moore JW (1973) Blocking of the rabbit's conditioned nictitating membrane response in Kamin's two-stage paradigm. J. Exp. Psychol. 101:155-158. Martin I, Levey AB (1991) Blocking observed in human eyelid conditioning. Q. J. Exp. Psychol. B. 43:233-256. McHose JH, Moore JN (1976) Expectancy, Salience and habit: an noncontextual interpretation of the effects of changes in the conditions of reinforcement on simple instrumental responses. Psychol. Rev. 83:292-307. Mellgren RL, Ost JW (1969) Transfer of Pavlovian differential conditioning to an operant discrimination. J. Comp. Physiol. Psychol. 67:390-394. Menzel R, Müller U (1996) Learning and memory in honeybees: from behavior to neural substrates. Annu. Rev. Neurosci. 19:379-404. Miles CG (1969) A demonstration of overshadowing in operant conditioning. Psych. Sci. 16:139-140. Miles CG, Jenkins HM (1973) Overshadowing in operant conditioning as a function of discriminability. Learn. Motiv. 4:11-27. Miller R-R, Matute H (1996) Biological significance in forward and backward blocking: Resolution of a discrepancy between animal conditioning and human causal judgment. J. Exp. Psychol. 125:370-386. Mosolff, M, Müller D, Hellstern F, Hammer M, Menzel R (1998) Effects of second order conditioning in honeybees are dependant on the inter stimulus interval. Europ. J. Neurosci 10:358. Nargeot R, Baxter DA, Byrne JH (1997) Contingent-dependent enhancement of rhythmic motor patterns: an in vitro analog of operant conditioning. J. Neurosci. 17:8093-8105. Nargeot R, Baxter DA, Byrne JH (1999a) In vitro analog of operant conditioning in Aplysia. I. Contingent reinforcement modifies the functional dynamics of an identified neuron. J. Neurosci. 19:2247-2260. Nargeot R, Baxter DA, Byrne JH (1999b) In vitro analog of operant conditioning in Aplysia. II. Modifications of the functional dynamics of an identified neuron contribute to motor pattern selection. J. Neurosci. 19:2261-2272. Pavlov IP (1927) Conditioned reflexes. Oxford: Oxford University Press. Pearce JM (1987) A model for stimulus generalization in palovian conditioning. Psychol. Rev. 94:61-73. Pearce JM (1994) Similarity and discrimination: a selective review and a connectionist model. Psychol Rev. 101:587-607. Pearce JM, Hall G (1978) Overshadowing the instrumental conditioning of a lever press response by a more valid predictor of the reinforcer. J. Exp. Psychol. Anim. Behav. Process.es 4:356-367. Pearce JM, Hall G (1980) A model for pavlovian learning: Variations in the effectiveness of conditioned but not of unconditioned stimuli. Psychol. Rev. 87:532-525. Pelz C, Gerber, B., & Menzel, R, (1997) Odorant intensity as a determinant for olfactory conditioning in honeybees: Roles in discrimination, overshadowing and memory consolidation. J. Exp. Biol. 200:837-847. Prewitt EP (1967) Number of preconditioning trials in sensory preconditioning using CER training. J. Comp. Physiol. Psychol. 64:360-362. Rescorla RA (1979) Aspects of the reinforcer learned in second-order Pavlovian conditioning. J. Exp. Psychol. Anim. Behav. Process. 5:79-95. Rescorla RA (1980) Simultaneous and successive associations in sensory preconditioning. J. Exp. Psychol. Anim. Behav. Process. 6:207-216. Rescorla RA (1982) Simultaneous second-order conditioning produces S-S learning in conditioned suppression. J. Exp. Psychol. Anim. Behav. Process. 8:23-32. Rescorla RA (1983) Effect of separate presentation of the elements on within compound learning in auto shaping. Anim Learn Behav 11:439-446. Rescorla RA (1994) Control of instrumental performance by Pavlovian and instrumental stimuli. J. Exp. Psychol. Anim. Behav. Process. 20:44-50. Rescorla RA, Cunningham CL (1979) Spatial contiguity facilitates Pavlovian second-order conditioning. J. Exp. Psychol. Anim. Behav. Process. 5:152-161. Rescorla RA, Gillan DJ (1980) An analysis of the facilitative effect of similarity on second-order conditioning. J. Exp. Psychol. Anim. Behav. Process. 6:339-351. Rescorla RA, Solomon RL (1967) Two-process learning theory: Relationships between Pavlovian conditioning and instrumental learning. Psychol. Rev. 74:151-182. Rescorla RA, Wagner AR (1972) A theory of Pavlovian conditioning: Variations in the effectiveness of reinforcement and nonreinforcement. In: Classical Conditioning II: Current research and theory (Black A, W.F. P, eds), pp 64-99. New York: Appleton-Century-Crofts. Rizley RC, Rescorla RA (1972) Associations in second-order conditioning and sensory preconditioning. J. Comp. Physiol. Psychol. 81:1-11. Rogers RF, Schiller KM, Matzel LD (1996) Chemosensory-based contextual conditioning in Hermissenda crassicornis. Anim. Learn. Behav. 24:28-37. Rogers RF, Matzel LD (1995) Higher-order associative processing in Hermissenda suggests multiple sites of neuronal modulation. Learn. & Mem. 2:279-298. Ross RT, LoLordo VM (1987) Evaluation of the relation between Pavlovian occasion-setting and instrumental discriminative stimuli: a blocking analysis. J. Exp. Psychol. Anim. Behav. Process. 13:3-16. [retracted by LoLordo VM, Ross RT. In: J. Exp. Psychol. Anim. Behav. Process. 1990 16(4):402-6]. Sahley C, Rudy JW, Gelperin A (1981) An analysis of associative learning in a terrestrial mollusc. J. Comp. Physiol. (A). 144:1-8. Schachtman TR, Kasprow WJ, Chee MA, Miller RR (1985) Blocking but not conditioned inhibition results when an added stimulus is reinforced in compound with multiple pretrained stimuli. Am. J. Psychol. 98:283-295. Schindler CW, Weiss SJ (1985) Modification of a stimulus-reinforcer interaction by blocking. Behav. Process. 11:123-130. Schultz W, Romo, R., Ljungberg, T., Mirenowicz, J., Hollerman, J.R., & Dickinson, A, (1995) Reward-related signals carried by dopamin neurons. In: Models of information processing in the basal ganglia, (J.C. Houk DGB, ed), pp 233-248. Cambridge, MA: MIT Press. Sekiguchi T, Suzuki H, Yamada A, Mizukami A (1994) Cooling-induced retrograde amnesia reflexes Pavlovian conditioning associations in Limax flavus. Neurosci. Res. 18:267-275. Sheffield FD (1965) Relation of classical conditioning and instrumental learning. In: Classical Conditioning (Prokasy WF, ed), pp 302-322. New York: Appleton-Century-Crofts. Skinner BF (1935) Two types of conditioned reflex and a pseudo type. J. Gen. Psychol. 12:66-77. Skinner BF (1937) Two types of conditioned reflex: A reply to Konorski and Miller. J. Gen. Psychol. 16:272-279. Skinner BF (1938) The behavior of organisms. New York: Appleton. Smith BH (1996) The role of attention in learning about odorants. Biol. Bull. 191:76-83. Smith BH (1997) An analysis of blocking in odorant mixtures: An increase but not a decrease in intensity of reinforcement produces unblocking. Behav. Neurosci.. 111:57-69. Smith BH (1998) Analysis of interaction in binary odorant mixtures. Physiol. Behav. 65:397-407. Spence KW (1936) The nature of discrimination learning in animals. Psych. Rev. 43:427-449. Spencer GE, Syed NI, Lukowiak K (1999) Neural changes after operant conditioning of the aerial respiratory behavior in Lymnea stagnalis. J. Neurosci 19:1836-1843. St. Claire-Smith R (1979) The overshadowing of instrumental conditioning by a stimulus that predicts reinforcement better than the response. Anim. Learn. Behav. 7:224-228. Sutton RS, Barto AG (1981) Toward a modern theory of adaptive networks: Expectation and prediction. Psychol. Rev. 88:135-170. Sutton RS, Barto AG (1990) Time-derivative models of pavlovian reinforcement. In: Learning and Computational Neuroscience: Foundations of Adaptive Networks (Gabriel M, Moore J, eds), pp 497-537. Boston: MIT Press. Suzuki H, Sekiguchi T, Yamada A, Mizukami A (1994) Sensory preconditioning in the terrestrial mollusk, Limax flavus. Zool. Sci. (Tokyo) 11:121-125. Tait RW, Black M, Katz M, Suboski MD (1972) Discriminative sensory preconditioning. Can. J. Psychol. 26:201-205. Tait RW, Suboski MD (1972) Stimulus intensity in sensory preconditioning of rats. Can. J. Psychol. 26:374-381. Takeda K (1961) Classical conditioned response in the honey bee. J.Insect Physiol 6:168-179. Thompson RF, Thompson JK, Kim JJ, Krupa DJ, Shinkman PG (1998) The nature of reinforcement in cerebellar learning. Neurobiol. Learn. Mem. 70:150-176. Trapold MA, Lawton GW, Dick RA, Gross DM (1968) Transfer of training from differential classical to differential instrumental conditioning. J. Exp. Psychol. 76:568-573. Trapold MA, Overmier JB (1972) The second learning process in instrumental conditioning. In: Classical Conditioning (Black AH, Prokasy WF, eds). New York: Appleton-Century-Crofts. Trapold MA, Winokur S (1967) Transfer from classical conditioning and extinction to acquisition, extinction, and stimulus generalization of a positively reinforced instrumental response. J. Exp. Psychol. 73:517-525. Tully T (1991) Of mutations affecting learning and memory in Drosophila - the missing link between gene product and behavior. Trends. Neurosci. 14:163-164. Tully T, Boynton S, Brandes C, Dura JM, Mihalek R, Preat T, Villella A (1990) Genetic dissection of memory formation in Drosophila . Cold Spring Harb. Symp. Quant. Biol. 55:203-211. Tully T, Preat T, Boynton SC, Del-Vecchio M (1994) Genetic dissection of consolidated memory in Drosophila. Cell. 79:35-47. Wagner AR (1981) SOP: A model of automatic memory processing in animal behavior. In Information processing in animals: Memory mechanisms. In: (N.E. Spear RPM, ed), pp 5-47. Hillsdale: Erlbaum. Wagner AR, Mazur JE, Donegan NH, Pfautz PL (1980) Evaluation of blocking and conditioned inhibition to a CS signaling a decrease in US intensity. J. Exp. Psychol. Anim. Behav. Process. 6:376-385. Wang X, Liu L, Xia SZ, Feng CH, Guo A (1998) Relationship between visual learning/memory ability and brain cAMP level in Drosophila. Sci. China C: L. Sci. 41:503-511. Ward-Robinson J, Hall G (1996) Backward sensory preconditioning. J. Exp. Psychol. Anim. Behav. Process. 22:395-404. Ward-Robinson J, Hall G (1998) Backward sensory preconditioning when reinforcement is delayed. Q. J. Exp. Psychol. B Comp. Physiol. Psychol. 51:349-362. Weidtmann N (1993) Visuelle Flugsteuerung und Verhaltensplastizität bei Zentralkomplex - Mutanten von Drosophila melanogaster. Würzburg: Diplomarbeit. Weiss SJ, Panilio LV (1999) Blocking a selective association in pigeons. J. Exp. Anal. Behav. 71:13-24. Williams BA (1975) The blocking of reinforcement control. J. Exp. Anal. Behav. 24:215-225. Williams BA (1978) Informational effects on the response-reinforcer association. Anim. Learn. Behav. 13:6-12. Williams BA (1994) Blocking despite changes in reinforcer identity. Anim. Learn. Behav. 22:442-457. Williams BA, Heyneman N (1982) Multiple determinants of blocking effects on operant behavior. Anim. Learn. Behav. 10:72-76. Williams BA, Preston RA, DeKervor DE (1990) Blocking of the response-reinforcer association additional evidence. Learn. Motiv. 21:379-398. Wolf R, Heisenberg M (1991) Basic organization of operant behavior as revealed in Drosophila flight orientation. J Comp Physiol A. 169:699-705. Wolf R, Heisenberg M (1997) Visual Space from Visual Motion: Turn Integration in Tethered Flying Drosophila. Learn. & Mem. 4:318-327. Wolf R, Wittig T, Liu L, Wustmann G, Eyding D, Heisenberg M (1998) Drosophila mushroom bodies are dispensable for visual, tactile and motor learning. Learn. & Mem. 5:166-178. Wolpaw JR (1997) The complex structure of a simple memory. Trends. Neurosci. 20:588-594. Xia SZ, Feng CH, Guo AK (1999) Temporary amnesia induced by cold anesthesia and hypoxia in Drosophila. Physiol. Behav. 65:617-623. Xia SZ, Liu L, Feng CH, Guo A (1997a) Memory consolidation in Drosophila operant visual learning. Learn. & Mem. 4:205-218. Xia SZ, Liu L, Feng CH, Guo AK (1997b) Nutritional effects on operant visual learning in Drosophila melanogaster. Physiol. Behav. 62:263-271. Zanich ML, Fowler H (1978) Transfer from Pavlovian appetitive to instrumental appetitive conditioning: signaling versus discrepancy interpretations. J. Exp. Psychol. Anim. Behav. Process. 4:37-49.