The startle reaction (also known as the startle response, the startle reflex, or the alarm reaction) is the psychological and physiological response to a sudden unexpected stimulus, such as a flash of light, a loud noise (acoustic startle reflex), or a quick movement near the face. Abnormalities of startle response have been observed in many stress-related mental disorders, such as schizophreni...

The startle response, a simple defensive response to a sudden stimulus signaling proximal threat, has been well studied in rodents and humans, but has been rarely examined in monkeys. The first goal of the present studies was to develop a minimally immobilizing startle measurement paradigm and validate its usefulness by testing two core features of the startle response (habituation and graded r...

The authors used affective modulation of the eyeblink startle response to examine the impact of traumatic brain injury (TBI) on emotional reactions to pictures. Participants were 13 individuals with severe TBI and 24 controls. Participants were presented with pictures that differed in affective valence (e.g., mutilated bodies, erotic couples, and household objects) while the eyeblink startle re...

Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending p...

Research has shown that during emotional imagery, valence and arousal each modulate the startle reflex. Here, two imagery-startle experiments required participants to attend to the startle probe as a simple reaction time cue. In experiment 1, four emotional conditions differing in valence and arousal were examined. Experiment 2, to accentuate potential valence effects, included two negative hig...

Escape swimming in the pteropod mollusk Clione limacina includes an initial startle response in which one or two powerful wing beats propel the animal up to 18 body lengths per second, followed by a variable period of fast swimming with a maximal speed of 6 body lengths per second. The initial startle response is the focus of this report. Two pairs of large pedal neurons (50-60 microns) initiat...

a r t i c l e i n f o Research has demonstrated the utility of emotion-modulated startle paradigms in assessing emotional regulation and processing. Previous research has documented various abnormalities in emotion regulation and processing among individuals with a history of childhood maltreatment. Less is known about the psychophysiological correlates of emotion processing among maltreated in...

The present study investigated the involvement of the human cerebellum in the habituation of the acoustic startle response using PET. The startle response was elicited in seven young, healthy subjects by a tone presented via headphones. Startle responses were recorded from the right sternocleidomastoid muscle. Regional cerebral blood flow (rCBF) was assessed in nine scans and one startle stimul...

An exaggerated startle response is one of the core hyperarousal symptoms of posttraumatic stress disorder (PTSD). Heightened startle eye-blink magnitude and reduced habituation of this response in PTSD patients have been reported in several studies. However, it is unclear whether this is an enduring characteristic of individuals vulnerable for PTSD or to which degree trauma-exposed individuals ...