Blocking of conditioning of tentacle lowering in the snail (Helix aspersa)

Abstract

Experiment 1 established the effectiveness of an appetitive conditioning of odours procedure with snails (Helix aspersa) that was subsequently used for the study of blocking. In this important phenomenon, the conditioning of a CS1 (where CS is the conditioned stimulus) prior to conditioning of a compound, CS1CS2, blocked the conditioning to the CS2. Experiments 2a, 2b, and 2c demonstrated this associative effect using three different experimental controls. Experiments 3a and 3b replicated the blocking effect and allowed us to reject an explanation of blocking based on generalized effects of several treatments of diverse stimuli in blocking and control groups (the pseudoblocking effect). The implications of these results for the study of invertebrate cognition by means of conditioning techniques are discussed.

Simple minds: a qualified defence of associative learning

“…Of yet more interest, however, is recent work providing evidence of associative learning in invertebrate species. For example, demonstrations, not only of conditioning, but also of blocking, have been reported in insects [3], molluscs [4] and platyhelminthes [5].…”

Competition and facilitation in compound conditioning.

“…Cue competition effects have been observed in both appetitively and aversively motivated tasks, and across a wide range of invertebrate species including planaria (Prados et al, 2013), snails (Acebes et al, 2009), and honeybees (Couvillon & Bitterman, 1989), as well as vertebrates such as rodents (Kamin 1968), pigeons (Leyland & Mackintosh, 1978), non-human primates (Waelti, Dickinson & Schultz, 2001), and humans (Dickinson, Shanks & Evenden, 1984).…”

Associative learning phenomena in the snail (Helix aspersa): Conditioned inhibition

“…that was located on the plastic tray by the snail. Previous research (Acebes et al, 2009;Loy et al, 2006) has demonstrated no differences in the CRs given to the different CSs at the beginning of a conditioning phase or in the course of conditioning when associated with the US. Despite this, the roles of the CSs (CS 1 -CS 2 ) were counterbalanced; we ran the experiment twice and merging the data in the analysis, as no significant differences were observed between them.…”

“…This is but one more step in an organized effort to replicate the relevant phenomena of associative learning in an invertebrate model (see Acebes et al, 2009;Loy et al, 2006;Ungless, 1998). This invertebrate model could be a useful instrument to use to further our understanding of the physiological bases of learning and memory.…”

“…Many instances of excitatory conditioning and other associative learning phenomena have been shown in invertebrate species; for example, sensory preconditioning, second-order conditioning, latent inhibition, overshadowing, and blocking have been observed in the common snail (Helix aspersa) using an appetitive excitatory conditioning procedure (Acebes, Solar, Carnero, & Loy, 2009;Loy, Fernández, & Acebes, 2006; for a review, see Farley, Jin, Huang, & Kim, 2004) This research allows for abridging the research on learning phenomena at three different levels: (1) the development of formal learning theories, (2) comparisons of the learning abilities of different species across the evolutionary tree, and (3) the study of the physiological correlates of learned changes in the behaviour of animals.…”