Re-emerging conceptual integration: commentary on Berkowitz's "on the consideration of automatic as well as controlled psychological processes in aggression"

In recent decades, researchers in various areas of psychology have challenged the claims of a single mode of information processing, and developed dual-process models of social behaviors. Although these theories differ on a number of dimensions, they all share the basic assumption that two different modes of information processing operate in making decision and copying behavior. In essence, the common distinction in these perspectives is between controlled vs. automatic, conscious vs. unconscious, and affective vs. cognitive modes of processing. The purpose of Berkowitz's article is to go beyond the notion of automatic processes in order to use classic notions of conditioning and displacement to explain aggressive behavior. I assert that an explanatory framework for psychology of aggression must be anchored not only in the new but also classic theoretical paradigms. However, progress in psychology does not rest solely on the accumulation of theoretical insights. It demands a large body of empirical facts, with attention to incongruities, discordances, and conceptual clarifications.     

Smells like sib spirit: kin recognition in three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>) is mediated by olfactory cues

The ability to recognise kin has been demonstrated in several animal species. However, the mechanisms of kin recognition often remain unknown. The most frequently discussed sensory modalities to recognise kin are visual, olfactory and acoustical cues. Three-spined sticklebacks (Gasterosteus aculeatus) are able to differentiate between kin and non-kin when presented visual and olfactory cues combined. To elucidate, which cues they use to recognise kin female sticklebacks were given the choice between two identical computer animations of courting stickleback males. Next to one animation, water conditioned by a brother was added, while near the other, water from an unrelated male was added. In half of the experiments, the brother was familiar while in the other half he was unfamiliar to the female. Both scenarios were carried out with both outbred and inbred fish. The results showed that the females adjusted their choice behaviour according to relatedness. Furthermore, they were able to recognise both familiar as well as unfamiliar brothers. Inbreeding did not affect this ability. Hence, three-spined sticklebacks are able to recognise their relatives using olfactory cues alone. The cognitive mechanisms underlying this ability were independent from familiarity and not impaired by inbreeding.     

Explicit disassociation of a conditioned stimulus and unconditioned stimulus during extinction training reduces both time to asymptotic extinction and spontaneous recovery of a conditioned taste aversion

Conditioned taste aversions (CTAs) may be acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). This aversion may be extinguished by repeated exposure to the CS alone. However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). In the current study we employed an explicitly unpaired extinction procedure (EU-EXT) to determine if it could thwart SR of a CTA. Sprague-Dawley rats acquired a strong CTA after three pairings of saccharin (SAC the CS) and Lithium Chloride (LiCl the US). CTA acquisition was followed by extinction (EXT) training consisting of either (a) CS-only exposure (CSO) or (b) exposure to saccharin and Lithium Chloride on alternate days (i.e., explicitly unpaired: EU). Both extinction procedures resulted in ?90% reacceptance of SAC, although the EU extinction procedure (EU-EXT) significantly decreased the time necessary for rats to reach this criterion (compared to CSO controls). Rats were subsequently tested for SR of the CTA upon re-exposure to SAC following a 30-day latency period of water drinking. Rats that acquired a CTA and then underwent the CSO extinction procedure exhibited a significant suppression of SAC drinking during the SR test (as compared to their SAC drinking at the end of extinction). However, animals in the EU-EXT group did not show such suppression in drinking compared to CSO controls. These data suggest that the EU-EXT procedure may be useful in reducing both time to extinction and the spontaneous recovery of fears.     

A one-trial inhibitory avoidance task to zebrafish: Rapid acquisition of an NMDA-dependent long-term memory

The behavioral tasks aiming to evaluate learning and memory mechanisms currently available to zebrafish (Danio rerio) involve long training sessions frequently along multiple days and are based on shuttle box or active-avoidance protocols, preventing a detailed analysis of cellular and molecular time-dependent processes involved in memory acquisition and consolidation. In order to explore zebrafish’s potential contribution to the characterization of the molecular machinery underlying learning and memory rapidly acquired and reliable paradigms are necessary. In this study we present a rapid and effective learning protocol in a single-trial inhibitory avoidance in zebrafish. In a simple apparatus, adult animals learned to refrain from swimming from a white into a dark compartment in order to avoid an electric shock during a single-trial training session that lasted less than 2 min. The resulting memory is robust, long-lasting and sensitive to NMDA-receptor antagonist MK-801 given in the tank water immediately after training. Experiments aiming to further characterize the events underlying memory formation, retrieval or extinction or those looking for cognitive profiling of mutants, neurotoxicological studies and disease models may benefit from this task, and together with complementary strategies available for zebrafish may significantly improve our current knowledge on learning and memory mechanisms.     

Behavioral and genetic characterization of habituation using Caenorhabditis elegans

This review surveys the literature that investigates the behavioral characterization and cellular and molecular mechanisms of habituation using the model organism Caenorhabditis elegans. In 1990, C. elegans was first observed to show habituation to a non-localized mechanical tap. The parameters that govern this behavioral plasticity in C. elegans were subsequently characterized, which lead to the important hypothesis that habituation is mediated by multiple mechanisms. Many tools are available to C. elegans researchers that allow for relatively easy genetic manipulation. This has lead to a number of recent genetic studies that have begun to identify key genes and molecules that play a role in the mechanisms of habituation. Some of these genes include a vesicular glutamate transporter, a glutamate receptor subunit, a dopamine receptor and downstream intracellular signaling molecules, such as G proteins and kinases. Some of these genes only affect certain parameters of habituation, but not others supporting the hypothesis that multiple mechanisms mediate habituation. The field of research has also led to the dissection of different phases of memory (short-term vs. long-term memory for habituation), which are triggered by different training paradigms. The differences in mechanism between these various forms of memory are also beginning to be revealed.     

Temperament, executive functions, and the allocation of attention to punishment feedback in passive avoidance learning

Several theories have been proposed to account for the apparent non-responsiveness to punishment cues or aversive events demonstrated by members of some disinhibited groups. Included among these theories are those that emphasize individual differences in temperament, temperament-related biases associated with the allocation of attentional resources, and impairments in executive functions. This study examined the relative contribution of each of these variables to the prediction of passive avoidance errors (PAEs, or failures to inhibit responding to punishment cues) during a computerized go/no-go task. Variations in temperament, attentional allocation to punishment feedback, and executive functions were found to independently and additively contribute to the prediction of PAEs in a mixed sample of men and women recruited at a university campus (n=145). Results from this study, therefore, support multiple theoretical perspectives on PAEs as assessed by the go/no-go experimental paradigm.     

Experiential avoidance and aversive visual images: response delays and event-related potentials on a simple matching task

In Experiment 1, participants high (n=15) or low in avoidance (n=14), as measured by the Acceptance and Action Questionnaire, completed a simple matching task that required them to choose whether or not to look at an aversive visual image. Only the high-avoidance participants took longer to emit a correct response that produced an aversive rather than a neutral picture. Additionally, the high-avoiders reported greater levels of anxiety following the experiment even though they rated the aversive images as less unpleasant and less emotionally arousing than their low-avoidant counterparts. In Experiment 2, three groups, representing high-, mid- and low-avoidance (n=6 in each) repeated the matching task with the additional recording of event-related potentials (ERPs). The findings of Experiment 1 were replicated in terms of reaction times and subjective ratings. The ERPs confirmed that the participants attended to the content of the images and differentiated between the aversive and neutral image types. The ERPs also showed significantly greater negativity for electrodes over the left hemisphere relative to the midline for only the high-experiential avoidance (EA) group. Given the left hemisphere dominance for language, the data suggest that the high-EA group engaged in verbal strategies to regulate their emotional responses.