Approach-avoidance Conflict Situation Research Articles

Differential encoding of events during approach–avoidance conflict situation by the prelimbic cortex

Differential encoding of events during approach–avoidance conflict situation by the prelimbic cortex

Toll-Like Receptor 4 Deficiency Causes Reduced Exploratory Behavior in Mice Under Approach-Avoidance Conflict.

Abnormal approach-avoidance behavior has been linked to deficits in the mesolimbic dopamine (DA) system of the brain. Recently, increasing evidence has indicated that toll-like receptor 4 (TLR4), an important pattern-recognition receptor in the innate immune system, can be directly activated by substances of abuse, resulting in an increase of the extracellular DA level in the nucleus accumbens. We thus hypothesized that TLR4-dependent signaling might regulate approach-avoidance behavior. To test this hypothesis, we compared the novelty-seeking and social interaction behaviors of TLR4-deficient (TLR4(-/-)) and wild-type (WT) mice in an approach-avoidance conflict situation in which the positive motivation to explore a novel object or interact with an unfamiliar mouse was counteracted by the negative motivation to hide in exposed, large spaces. We found that TLR4(-/-) mice exhibited reduced novelty-seeking and social interaction in the large open spaces. In less stressful test apparatuses similar in size to the mouse cage, however, TLR4(-/-) mice performed normally in both novelty-seeking and social interaction tests. The reduced exploratory behaviors under approach-avoidance conflict were not due to a high anxiety level or an enhanced fear response in the TLR4(-/-) mice, as these mice showed normal anxiety and fear responses in the open field and passive avoidance tests, respectively. Importantly, the novelty-seeking behavior in the large open field induced a higher level of c-Fos activation in the nucleus accumbens shell (NAcSh) in TLR4(-/-) mice than in WT mice. Partially inactivating the NAcSh via infusion of GABA receptor agonists restored the novelty-seeking behavior of TLR4(-/-) mice. These data suggested that TLR4 is crucial for positive motivational behavior under approach-avoidance conflict. TLR4-dependent activation of neurons in the NAcSh may contribute to this phenomenon.

Revised reinforcement sensitivity theory and vigilance eye-movement of BIS in conflicting situation

Revised reinforcement sensitivity theory (rRST) postulates individuals with behavioral inhibition system (BIS) would show improved behavioral responses and approach tendency with vigilance toward punishment in an approach-avoidance conflict situation. The aim of current study was to examine rRST by observing vigilant eye-movements and efficient behavioral response of BIS in conflicting situation. Twenty participants with high BIS and twenty participants with low BIS performed approach-avoidance conflict task. Eye-movements were observed using an eye tracking device which indicates resource allocation to resolve the conflicting situation. High BIS showed significantly more vigilant eye-movements and better task performance compared to low BIS. The result supports the rRST and the attentional process indicates converting approach motivation into an actual action. Individuals with BIS may be able to approach and resolve threatening stimuli rather than to avoid punishment if it is offered with reward.

Are high-impulsive and high risk-taking people more motor disinhibited in the presence of incentive?

In this study we assess the ability to inhibit certain planned actions in relation to the impulsiveness and venturesomeness traits of personality using the stop-signal paradigm. In the first condition subjects performed the stop-signal task without incentives. In the second condition, subjects performed the same task using an approach-avoidance conflict situation: speed of response was rewarded and the lack of inhibition was punished. Twenty male subjects were selected after preliminary testing using the impulsivity subscale from the Eysenck Personality Inventory. The main findings were: (1) no deficit in motor inhibition was found for high-impulsive subjects; estimated mean reaction times of inhibitory processes were the same for both high- and low-impulsive groups and (2) the presence of an incentive in the conflict situation affected motor inhibition for low venturesomeness subjects, who adopted a more cautiousness response strategy.

Assessment of individual differences in the preferred proximity to a human feeder by partitioned raisin test, with two species of macaque monkeys

All animals must acquire food and mates by approaching them despite possibilities of accompanying risks and thus are frequently encountered with approach-avoidance conflicts in daily lives. Behavioral individual differences in such situations may be considered as one of the most biologically fundamental personality trains. “Partitioned raisin test” was devised to assess this trait with macaque monkeys. It involved throwing raisins into groups of monkeys and observing the preferred distance of each from the human feeder, a source of possible harm. The test was administered to 4 groups of Japanese monkeys (30 total) and 3 groups of rhesus monkeys (19 total), all l-yr-old and matched in history. Individual differences in the preferred proximity to the feeder, as expressed by the Proximity Index (PI), were found in both species.PI was not correlated with a measure of dominance over the raisins. Individual differences inPI were also not due to territorial effects unrelated to the location of the feeder.PI was stable in five of the six monkeys re-tested after one year of interval in a newly organized group, where there supposedly had been a change in their social structure. Partitioned raisin test was shown to be capable of depicting individual differences related to differential approach bias in an approach-avoidance conflict situation. Although possible confounding effects by social factors need to be delineated in the following studies, the method may provide a handy and widely applicable way for the assessment of this trait with monkeys.

Social influences on the reactivity of heifers: Implications for learning abilities in operant conditioning

The first experiment investigated the learning abilities of different types of heifers and the capacity of familiar conspecifics to reduce their behavioural reactivity. Two groups of 12–15 month-old Friesian and Aubrac (French breed) heifers were used. Ten animals of each breed were tested individually: 5 alone and 5 in the presence of the two other group mates. Heifers were trained daily, using an operant conditioning method, to press a panel (conditioned response) in order to obtain food. The number of trials necessary for the animals to learn the response was recorded. Their reactions towards the novel conditioning apparatus and pairing the food with a stressful stimulus were measured in the first phases of the conditioning procedure. In the absence of conspecifics, Aubrac heifers learnt more slowly than the other animals. At the onset of the conditioning test, they exhibited more signs of disturbance towards fear-eliciting stimulation. The differences in reaction between the two breeds were explained in terms of different levels of social attachment and novelty of the surroundings. A second experiment was conducted using the same conditioning procedure to repeat the first experiment and to assess the influence of affinity relationships with spectator conspecifics on the reactivity of heifers. Twenty-four 2-year-old Salers (French breed) heifers were tested: 8 alone and 16 others in the presence of two companions for which they had either a strong (8 animals) or a weak affinity (8 animals). The reactivity of each animal was assessed as previously in a novel environment and in an approach-avoidance conflict situation. As in the first experiment, the presence of peers improved the behavioural responsiveness towards the fear-inducing situations. Only one measure differentiated the subjects according to the social quality of the “spectator” companions: the time heifers spent feeding near the spectators was positively correlated with their affinity. The importance of the “spectator” companions' reactivity and the communication of stress is discussed.

Modulation of aversively motivated learning in rats adapted to a cold stressor

Two experiments studied effects of adaptation to cold water stress upon learning in two aversively motivated (shock) tasks. Experiment 1 found animals previously experiencing cold water stress exhibited more tolerance to shock, having shorter latencies, in an approach-avoidance conflict situation than non-treated controls. In Experiment 2, animals with previous cold water stress experience exhibited longer response latencies than controls in an active-avoidance task. These findings provide evidence that adaptation to a noncontingent stressor can modulate behavioral responses which suggest increased tolerance.

The Swinging Pendulum of Correctional Reform

Criminal justice professionals as well as the generalpublic are urging a return to fixed prison sentences, thereby undoing the efforts of twentieth century reformers to rely on the indeterminate sentencefor rehabilitation purposes. This movement is related to contradictory ideas concerning: (a) the purpose of the criminal justice system; (b)particularism versus universalism; and (c) the proper role of discretion in the administration ofjustice. The polarities inherent in each issue place society in a double approach-avoidance conflict situation which explains the pendulum movement of correctional policy. By seeking a middle-ground such as is offered by sentencing to community service, the search for a more just system may be enhanced.

Adaptation to the Punishing Effects of Cold Water

In order to investigate the reduction of the punishing effects of a cold-water barrier in an approach-avoidance conflict situation, three groups of rats ( N = 27) were trained to run a straight alley for a reward. After initial approach training the alley was modified by the installation of a water trough in front of the goal. When all groups were tested with 50°F water in the barrier, Ss trained with gradually declining water temperatures in the barrier performed significantly better ( p < .01) than Ss trained with a constant water temperature of 50°F or Ss trained with 95°F water in the trough. The results are related to those of similar experiments using electric shock as the punishing stimulus.

Exposure to electric shock and performance in an approach-avoidance conflict situation.

Exposure to electric shock and performance in an approach-avoidance conflict situation.

Approach-avoidance conflict behavior as a function of amount and spacing of prior electric shock

In a factorial study, albino rats were subjected to either six 5-sec. or 30 1-sec. electric shocks for either one or five days and were subsequently tested in an approach-avoidance conflict situation with shock used as the aversive stimulus. The effectiveness of the punishment in the conflict situation did not vary as a function of the spacing or amount of prior electric shock. However, all prior-shock groups were more sensitive to subsequent electric shock than was a no-prior-shock control group.

Approach-avoidance conflict behavior as a function of prior shock stimulation

Albino rats received a series of spaced 1-sec. shocks administered in then homecages for five consecutive days, and were later tested in an approach-avoidance conflict situation with either shock or airblast. Compared to control groups the prior-shock Ss were initially less sensitive to the effects of electric shock in the conflict situation.

Effects of shock intensity, deprivation, and morphine in a simple approach-avoidance conflict situation.

The effects of water deprivation, shock level, and morphine on punishment-induced suppression of water drinking during a single conflict acquisition session were studied. Suppression of drinkometer-recorded licking was greatest with high levels of intermittent foot-shock for drinking, and suppression was reduced by morphine. Level of deprivation had no significant effect.