Head-waving, a spontaneously occurring exploratory and appetitive behavior of the marine mollusc Aplysia, provides an opportunity to examine mechanisms of learning expressed in a nonreflexive behavior. The present study explores nonassociative and associative forms of learned modification of head-waving produced using an aversive stimulus as reinforcement. Experiments on intact, freely behaving...

Electrical injuries are becoming more common and are increasingly imaged with advanced technologies, such as MR imaging. However, the MR imaging findings of such injuries remain largely unstudied. We report a high-voltage electrical injury to the cerebral corticospinal tracts and document evolution on serial MR images.

It is unknown whether birds are able to retain the memory of purely sensory auditory information such as white noise over an extended period of time. In a Pavlovian heart rate conditioning paradigm, four pigeons were trained to associate a mild electric shock with periodic random waveforms, and no shock with aperiodic noise. Periodic waveform detection requires echoic memory, i.e., the online r...

The ethical conduct of research on posttraumatic stress disorder (PTSD) requires assessing the risks to study participants. Some previous findings suggest that patients with PTSD report higher distress compared to non-PTSD participants after trauma-focused research. However, the impact of study participation on participant risk, such as suicidal/homicidal ideation and increased desire to use dr...

When someone steps on your toe on purpose, it seems to hurt more than when the person does the same thing unintentionally. The physical parameters of the harm may not differ—your toe is flattened in both cases—but the psychological experience of pain is changed nonetheless. Intentional harms are premeditated by another person and have the specific purpose of causing pain. In a sense, intended h...

PURPOSE To psychometrically evaluate painDETECT, a patient-reported screening questionnaire for neuropathic pain (NeP), for discriminating among sensory pain symptoms (burning, tingling/prickling, light touching, sudden pain attacks/electric shock-type pain, cold/heat, numbness, and slight pressure). METHODS The seven-item version of painDETECT provides an overall score that targets only sens...

Associating sensory cues with aversive outcomes is a relatively basic process shared across species. Yet higher-order cognitive processes likely contribute to associative fear learning in many circumstances, especially in humans. Here we ask whether fears can be acquired based on conceptual knowledge of object categories, and whether such concept-based fear conditioning leads to enhanced memory...

From early on in his thinking, Sigmund Freud was attentive to the issue of helplessness in psychic functioning. Whereas Freud linked helplessness primarily to the affect of anxiety, later theoreticians like Edward Bibring conceptualized it as linked to depressive affects. The idea that helplessness is connected to depression is now well established in both psychiatry and psychology. Within a co...

Using aversion learning techniques, the relative aversiveness of CO(2) to pigs in comparison to a shock with an electric prodder, and the aversiveness of a CO(2)-stunner crate in comparison to the aversiveness of a V-belt restrainer used for electric stunning were examined. The results showed that 90% CO(2) was considerably less aversive than an electric shock with a prodder. However, during ex...

This study focused on autonomic responding in participants who scored high vs. low on the Neuroticism-Anxiety (N-Anx) and Impulsive-Sensation Seeking (Imp-SS) dimensions of the Zuckerman-Kuhlman Personality Questionnaire--Form III. Participants were presented with series of tones (standards, deviants and novels) and they received a mild electric shock (one, two or three pulses) at each 15th ton...