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Functional analyses and treatments of self‐injurious behavior and aggression have shown that such behavior is often operant. In this paper, we will revisit evidence that a subset of self‐injurious and aggressive biting may be controlled primarily by antecedent events and may have phylogenetic origins. We propose that there is a research gap of more than four decades, if one considers the wealth of basic research on biting that occurred prior to 1977. To our knowledge, that body of basic research was never fully translated or directly applied within behavior analysis. It is known that organisms (including humans) sometimes bite in the presence of aversive events (broadly defined as the presentation of aversive stimuli or the removal of reinforcers). Thus, the variables controlling biting in the context of behavioral assessment and treatment require further analysis. [ABSTRACT FROM AUTHOR]

Attentional bias to threatening visual stimuli (words or pictures) is commonly present in anxious individuals, but not in non-anxious people. There is evidence to show that attentional bias to threat can be induced in all individuals when threat is imposed by threat not of symbolic nature, but by cues that predict aversive stimulation (loud noise or electric shock). However, it is not known whether attentional bias in such situations is still influenced by individual differences in anxiety. This question was addressed in two experiments using a spatial cuing task in which visual cues predicted the occurrence of an aversive event consisting of a loud human scream. Speeded attentional engagement to threat cues was positively correlated with trait anxiety in Experiment 1. Experiment 2 showed that speeded attentional engagement was present only in participants selected for high anxiety but not in low-anxious participants. In both experiments, slower disengagement from threat cues was found in all participants, irrespective of their trait anxiety levels. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this project was to identify measurable physiological responses linked to the human experience of distress in a non-communicative state. Since sleep is a state of sensory-motor detachment in which subjects cannot report how they feel or what they experience, it can be considered a suitable model of non communicative states. A transitory distress-related response has consistently been reported in healthy awake subjects in the form of power spectrum alpha band changes in frontal brain areas. Hence, changes in frontal alpha asymmetry (FAA) were analysed in 16 volunteers before and after administration of distressful aversive stimuli during sleep. Transient physical or emotional distress was achieved by presentation of conditioned (to electroshocks or affective images) or directly-applied aversive stimuli (electroshocks). Frontal beta asymmetry (FBA) was also evaluated for comparisons. Power spectrum data were assessed from frontal electroencephalographic (EEG) leads (F3/F4). Galvanic skin response (GSR) and heart rate (HR) were also simultaneously monitored. To test the possibility that the short lasting stimulations would have long-term physiological effects, we included saliva cortisol sampling, evaluation of dream emotional valence and a standard assessment of sleep quality measurements. Aversive stimulation of diverse nature, compared to neutral valence stimuli, produced measurable changes in FAA (left>right) and in GSR evoked responses in both stage 2 (S2) and rapid eye movement (REM) sleep suggesting implicit processing of experiences with negative valence. Noticeably, dream content evaluation showed a trend towards increased negative emotionality. No FBA was observed, confirming the specificity of FAA responses. Saliva cortisol, and sleep parameters were not significantly affected by the protocol. This is, to our knowledge, the first time that an aversive imaging conditioning protocol has been successfully applied during sleep. [Copyright &y& Elsevier]

Abstract: Previous studies suggest that the magnocellular pathway, a visual processing system that rapidly provides low spatial frequency information to fast-responding structures such as the amygdala, is more involved in the processing of emotional facial expressions than the parvocellular pathway (which conveys all spatial frequencies). The present experiment explored the spatio-temporal characteristics of the spatial frequency modulation of affect-related neural processing, as well as its generalizability to non-facial stimuli. To that aim, the event-related potentials (ERPs) elicited by low-pass filtered (i.e., high spatial frequencies are eliminated) and intact non-facial emotional images were recorded from 31 participants using a 60-electrode array. The earliest significant effect of spatial frequency was observed at 135ms from stimulus onset: N135 component of the ERPs. In line with previous studies, the origin of N135 was localized at secondary visual areas for low-pass filtered stimuli and at primary areas for intact stimuli. Importantly, this component showed an interaction between spatial frequency and emotional content: within low-pass filtered pictures, negative stimuli elicited the highest N135 amplitudes. By contrast, within intact stimuli, neutral pictures were those eliciting the highest amplitudes. These results suggest that high spatial frequencies are not essential for the initial affect-related processing of visual stimuli, which would mainly rely on low spatial frequency visual information. According to present data, high spatial frequencies would come into play later on. [Copyright &y& Elsevier]

Abstract: The medial prefrontal cortex (mPFC) modulates neurovegetative and behavioral responses, being involved in memory, attention, motivational and executive processes. There is evidence indicating that mPFC modulates cardiovascular correlates of behavioral responses to stressful stimuli. Acute restraint is an unavoidable stress situation that evokes marked and sustained cardiovascular changes, characterized by elevated blood pressure (BP) and intense heart rate (HR) increase. We presently report effects of mPFC pharmacological manipulations on BP and HR responses evoked by acute restraint in rats. Bilateral microinjection of 200 nl of the unspecific synaptic blocker CoCl2 (1 mM) in the mPFC prelimbic area (PL) increased HR response to acute restraint, without significant effect on the BP response. This result indicates that PL synaptic mechanisms have an inhibitory influence on restraint-evoked HR changes. Injections of the non-selective glutamatergic receptor antagonist kynurenic acid (0.02M) or the selective N-methyl-d-aspartic acid (NMDA) receptor glutamatergic antagonist (LY235959) (0.02 M) caused effects similar to cobalt, suggesting that local glutamatergic neurotransmission and NMDA receptors mediate the PL inhibitory influence on restraint-related HR responses. Pretreatment with the non-non-N-methyl-d-aspartic acid glutamatergic antagonist glutamatergic antagonist glutamatergic receptor antagonist NBQX (0.02 M) did not affect restraint-related cardiovascular responses, reinforcing the idea that NMDA receptors mediate PL-related inhibitory influence. Pretreatment with the glutamatergic-receptor antagonists did not affect baseline BP or HR values. I.v. pretreatment with the quaternary ammonium anticholinergic drug homatropine methyl bromide (0.2 mg/kg) also increased the restraint-related HR response to values similar to those observed after treatment with kynurenic acid or LY235959, thus, suggesting that PL inhibitory influence on restraint-evoked heart rate increase could be related to increased parasympathetic activity. This dose of homatropine had no significant effects on baseline BP or HR values. Results suggest a PL inhibitory influence on restraint-evoked HR increase. They also indicate that local NMDA receptors involved in parasympathetic activation mediate PL inhibitory influence on restraint-evoked HR increase. [Copyright &y& Elsevier]

Violence on psychiatric wards involving staff and patients is a significant problem in many countries. Whilst patient psychopathology is often a factor, the violent interaction between ward staff and patients is often comparable to other violent interactions in the outside world. Thus, approaches from the social sciences can help to analyse the interactional patterns on psychiatric wards in order to benefit from their similarity to “ordinary” violent interactions. The concepts of aversive stimulation and double contingency are applied here to conclude that many acts of violence on wards occur following frustration or other rule imposition by staff. Both staff and patients can be seen as coping with perceived threat presented by the other in the interaction in a context of uncertainty about the behaviour of the other. The combination of misunderstanding, reciprocal anger and need for safety underpins an escalating tension in the interaction. These notions help us to understand these interactions better and could be incorporated in training for mental health staff. [ABSTRACT FROM AUTHOR]

Previous microdialysis studies measuring extracellular dopamine levels in response to unconditioned and conditioned aversive stimuli have used relatively long (e.g. 10 min) sample durations, such that more than one stimulus event occurred within a single dialysis sample. The present study used 1 min dialysate sampling to measure changes in dopamine levels in response to individual stimulus presentations.The changes evoked by mild footshock showed an initial enhancement from the first to the second presentation, after which there was a steady decline in the response over subsequent presentations. Compared to the responses to footshock alone, when the footshock was paired with an unfamiliar tone, there was no change in the response to the first stimulus presentation, but a significant augmentation of responses during subsequent presentations, giving weight to the view that dopamine is not involved in the learning per se, but rather in the processing of learned information.Whilst an unfamiliar tone had no measurable effect on extracellular dopamine levels, the same tone which had previously been paired with footshock evoked a significant increase in dopamine during the tone presentation, indicating that it is the aversive nature of the stimulus onset rather than the ‘rewarding’ nature of its offset which increases extracellular dopamine. [Copyright &y& Elsevier]

It was predicted from the dopamine-opiate system hypothesis that aggression induced by light tail pressure would be modified by exposure of the animals to radiofrequency electromagnetic energy. In a series of three experiments, it was found that there was a substantial decrease in aggressive behavior during exposure to EM energy at incident power densities as low as 50 μW/cm². This is consistent with previously published reports that indicate the dopamine and opiate systems of the brain are influenced by exposure to low-intensity EM energy. It would appear that EM energy exposure could be used as a probed in the study of aggression and in relating it to brain chemistry. Since this energy has become ubiquitous in the environment, and quite uneven in distribution, there may be implications for understanding aggressive behavior from a clinical standpoint as well as from the standpoint of necessary controls in experiments. [ABSTRACT FROM AUTHOR]

• A temporal structure was found in the behavioural response to aversive stimuli. • Animals were tested through a modified version of Novel Object Recognition task. • Conventional quantitative approaches and T-pattern analysis were used. • An over time influence of learning was observed on behavioural organization. Aim of the research was to investigate whether a temporal structure could be detected in the behavioural response to an aversive stimulation. A fear-related memory task was used in rats, placed in a modified version of the Novel Object Recognition task known as Emotional Object Recognition task, i.e. a behavioural assay that orbits around the declarative memory for an aversive experience. To this purpose, twelve male Wistar rats, divided in two groups (Control and Aversive memory), observed after 4 h (OR4h) and after 24 h (OR24h) from the delivery of an aversive stimulation, associated to a specific object, were used. Data were evaluated both in terms of conventional quantitative approaches and by means of T-pattern analysis, namely a multivariate technique able to unveil the temporal structure of behaviour and the relationships amongst the behavioural items in time. Results evidenced several changes between groups and over time as well. Mean occurrences and mean durations showed significant differences between OR4h and OR24h sessions and between Control and Aversive memory groups for behavioural items of Exploration, Object-related aversion and Immobility. T-pattern analysis revealed important changes of behavioural variability, complexity and repetitiveness, (i.e., the three main qualitative features of T-patterns) in the Aversive memory group. These outcomes highlight a simpler and linear behavioural profile, focused only on specific sequences of particularly repetitive events. Overall, the present study demonstrates a) the presence of a temporal organization of fear-related behavioural events and b) the influence of learning on the modifications observed over time. [ABSTRACT FROM AUTHOR]