The startle pattern, also known as startle reaction or startle response, is a sudden and brief and largely unconscious reaction to being startled, such as a loud noise.
The startle pattern has its origin in the startle reflex which is a brain stem reaction. It exists in humans, all apes and monkeys, and many other animals.
The auditory startle reflex has been investigated the most, but some other surprising (and unpleasant) stimuli – mainly in older studies – include a photo flash, a jet of ice water between the shoulder blades, the application of an electric shock to a hand, or a pinprick to the right thigh. The startle pattern is mainly measured by using high speed film, running for example at 1,500 frames per second, or by EMG.
The startle pattern in the adult human consists of tightening of the jaw, blinking of the eyes, head movement forward, a characteristic facial expression, raising and drawing forward of the shoulders, stiffening of the arms, forward movement of the trunk, contraction of the abdomen, and bending of the knees.
The duration of the whole sequence is dependent on the intensity of the stimulus and hence the intensity of the response, from 0.2 sec to 1.5 sec. It is transitory, people normally recover quickly. Intensity increases the reaction, for example by the use of a .32 caliber gun instead of a .22 caliber gun. The startle pattern is independent of the source of the noise: wherever it happens the pattern is the same.
By habituation, repeating the stimulus within a couple of minutes, people can prevent the body response, but never the eye blink and rarely the head movement. Even if the subject fires the gun him- or herself, there is a little startle in form of eye blinking and head movement (neck stiffening). The same happens to experienced policemen on the shooting range. In a study the facial distortion surprised the policemen since they believed they did not make any. People can diminish the amount of response somewhat but never eliminate it. Combining it with other activity does not alter the basics: startle pattern happens to runners when they hear the start gun.
The startle pattern has been studied since the latter part of the 19th century. A detailed investigation (and a source for Frank P. Jones) was The Startle Pattern (1939).
It has been argued that it is closely related to the Moro reflex. The Moro reflex is present at birth, peaks in the first month of life and begins to disappear around 2 months of age. It is likely to occur if startled by a sudden noise. The legs and head extend while the arms jerk up and out with the palms up and thumbs flexed. Shortly afterward the arms are brought together and the hands clench into fists, and the infant cries loudly. The Moro is therefore first one of extension, then flexion. The Moro reflex is one of several early or ‘primitive’ reflexes. They are reflex actions originating in the central nervous system that are exhibited by normal infants but not in neurologically intact adults, in response to particular stimuli. These reflexes disappear or are inhibited by the frontal lobes as a child moves through normal child development. These primitive reflexes are also called infantile, infant or newborn reflexes. However, there is no obvious connection except a reaction to being startled.
Others have compared it to the fight-or-flight response, or the stress response, or the escape response. It would appear that the fight-or-flight response is a later response than the startle pattern, which has raised the question as to whether the startle pattern is a precursor to fight-or-flight reaction. It is under discussion whether the startle pattern in humans constitutes adapative behaviour or whether it is a relic of or a more complex form of withdrawal reaction which are common to almost all organisms. The authors of a study in 1991 write: ‘We suggest therefore that the physiological importance of the auditory startle reflex in humans lies in the rapid accomplishment of a defensive stance with maximum postural stability.’ However, a 2005 study on the performance of aircraft pilots found a deleterious effect of the startle pattern. The ‘threat has the effect of potentiating startle effects and has significant deleterious effects on cognition. This could contribute to poor performance following an unexpected critical event in aviation.’
Frank P. Jones on the startle pattern
Jones reported on startle pattern, and summarised some of the research in his writings.
In ‘An electromyographic technique for recording the startle patten’ F. P. Jones reports on his study on the onset and duration of muscle activity in response to a different startle sounds (from a 22 caliber revolver shot to that of a dropped board), subjects were 8 men between 21 and 50 years of age. The response of the neck was most readily and consistently recorded, irrespective of the stimulus strength. Jones also used a force platform, i.e. a platform that measures the force applied when standing on it, and observed that there is a brief ‘lift’ before the downward flexion.
Relevance for the Alexander Technique
Teachers of the Alexander Technique have seen in the research on the startle pattern evidence for 1. the head-to-tail progression of movement, i.e. a total pattern of reaction starting with the head and neck and proceeding downwards; 2. a universal pattern of misuse, a pattern whose characteristics constitute the opposite of what the Alexander Technique is aiming to cultivate. That is, the startle pattern involves a downwards pull of the head and neck and a general flexion whereas the Technique involves a freeing of the neck so that the head can go forward and up, and a general extension.
Additionally, it is sometimes hypothesised, sometimes claimed, that stress, fear or anxiety are stimuli which can also provoke the startle pattern, and that repeated mini-startles constitute a major source of misuse. For example, these are quotes from introductory books to the Alexander Technique:
When one looks at people in the streets, it would seem that the startle pattern is more and more the norm for people as they get older. (Chris Stevens, 1987.)
For by now a modified form of quasi-permanent ‘startle pattern’ is so general that few people question it in themselves or in others. Reactions of the ‘startle’ type (figs. 59–75) now look and feel so familiar that they seem ‘natural’. (Elizabeth Langford, 1999.)
Often referred to as the ‘startle pattern’, our response to life-threatening situations enable us to escape from and deal with danger. However, this instinctive reaction can also become habitual if constantly repeated, with serious health consequences. (Noel Kingsley, 2011.)
The Art of Changing by Glen Park (1989) also contains a discussion of the startle response.
F. M. Alexander
F. M. Alexander referred to ‘fear reflexes’ (and generally to ‘fear’) in several places in his writings.   One chapter title in CCC is ‘VI. Unduly excited fear reﬂexes, uncontrolled emotions, and fixed prejudices’. There are no references to the startle pattern in Alexander’s writings.
It is also possible that misuse in general is not related to the startle pattern even though they share common characteristics.