What Is The Startle Reflex?

Pinnington, N., Elliott, A., Sciences, F. of L., Manchester and Kingdom, U. (2007) Proceedings of the physiological society. Available at: http://www.physoc.org/proceedings/abstract/Proc%20Physiol%20Soc%208PC39 (Accessed: 3 March 2016).

In this classical conditioning experiment, the tapping of the person’s knee with a clinical hammer is the UCS, as it is a naturally occurring stimulus that elicits the UCR, which in this case is the reflexive knee jerk action. The distinctive sound given out by the buzzer was initially the NS, but eventually became the CS, after 20 to 30 pairings with the UCS within close intervals of 5 seconds during the experiment. It has become a stimulus that is subsequently capable of eliciting a learned reflex response on its own (CR) which was originally an UCR, because it has been paired with the original UCS.

Startle reflex- when babies hear a sudden sound or see a bright light, they move their arms outwards, and clenching their fists

24) You remember as a child seeing a "fly" buzzing on a flower and trying to catch it. You also remember the pain and your hand automatically jerking away. Although you didn't know it at the time, your reflexive withdrawal was controlled by your

To first understand the importance of the clinical reaction time test, the physiological pathways involved in reaction time must first be

Notably, the human brain plays a key role in how we feel or respond to situations around us. Neural circuitry and the transmission of neurotransmitter play a key role in emotion, rewards and aggressive behavior. These circuitry is inborn and exist in every human being. Aggressive responses by Grendel’s mother to the cry of her son to free him from his ordeal are because of inner workings within and around her brain. According to a human research carried out by Mary E. Braine, “The hypothalamus plays a critical role in the physiological responses through both integration and output of human responses. The hypothalamus controls the autonomic nervous system and thus is key in generating the physiological

The Holocaust: A genocide in which six million Jews died, still remembered today as the single most grotesque massacre in human history. For most, the concept of Hitler’s rise to power, the building of his strength, and the process by which his orders were carried out remains an unimaginable concept. In the mind, laws of morality don’t bend. In looking at the Holocaust, one has to wonder how so many managed to break the rules of humanity so quickly. The easiest answer questions the existence of ethical laws at all. Although others consider the vast majority who did not fall victim to Hitler’s power to simply be better people, a consensus of Germany pre-war reveals that they were not miniature bigots.

The second series of experiments examined sensitization by determining both the time of onset of sensitization, as well as, the magnitude of sensitization when intensity of stimuli is manipulated. To do so, experimenters utilized the same experimental design as that of the dishabituation experiment; however, the animals were presented two baseline stimuli at equal intervals before tail stimulus and then an additional

Reflexes are the neurologist’s window to the brain – yet our knowledge of some reflexes is still limited. Startle is an ubiquitous brainstem reflex to sudden, intense stimuli, but it is not clear how basic psychological processes such as attention or motor planning influence the startle reflex or whether it serves as an interrupt or facilitator of concurrent actions. Combining classic experimental and novel neuromodulatory techniques with the measurement of oscillatory brain activity, this project will fill these knowledge gaps. This knowledge will inform the development of physiologically based theories of cognitive function and the design of interventions to reduce the negative effects of sudden, distracting events.

One of the oldest forms of survival is the fight or flight response. Numerous examples of outrageous feats performed by people can be found, but the most pure form can be found in those who still use it daily, and actually use it for survival. Animals utilize their fight or flight response to survive in nature, where a delay or lapse in judgement could result in their death.

Maslovat et al. [10] proposed that the detection of SCM activity indicates that a more direct neural circuit, common with the startle reflex, was responsible for involuntarily triggering the prepared response. Thus, when responses occur without SCM activity (SCM-), the longer typical neural circuit - involving the auditory cortex - would trigger the motor response. This model would explain why responses are faster when SCM activity is observed. Interestingly, the StartReact effect can still be observed when the startle reflex is abolished due to the presentation of a less intense stimulus before the go-signal (pre-pulse inhibition or PPI)[16]. This is counterintuitive because it suggests that the more direct neural circuit is still activated when the transient activation of the midbrain nuclei by PPI stimulus exerts long-lasting inhibition of the giant neurons of the caudal pontine reticular nucleus [34]. Alternatively, we have suggested that the apparent correlation between SCM activity and premotor RT could be a result of variations in the build-up of

Voluntary and involuntary reactions to intense sensory stimulation provide a gateway to investigate underlying psychophysiological processes in the brain such as attention, motor planning, and fear conditioning. Yet, little attention has been paid to how time varying fluctuations in brain excitability affect these reactions. Using a combination of classic psychophysiological techniques and novel neuromodulatory techniques, this project seeks to provide greater understanding of how the dynamic changes occurring in the brain shape the manifestation of voluntary and involuntary responses. This fundamental knowledge will have important implications across many fields, including cognitive neuroscience, sports science, and applied

Infantile reflexes include the tonic neck reflexes, grasping reflexes and many others. As the neocortex begins to mature, it inhibits these primitive reflexes, causing them to disappear in normal adults. However, in people with frontal or parietal lobe damage or tumours, these reflexes are reactivated. This raises the question: What kind of mechanisms does the neocortex employ to exert inhibitory control over such reflexes? Since the brain is so complex, a vast variety of possible mechanisms could exist and be utilised by the frontal and parietal lobes to suppress the reflexes. Perhaps, there could be neuronal projections to the reflex centres where inhibitory neurotransmitters such as GABA halt those reflexes. Another possibility could be

Anticipation is essential to prepare the motor system for voluntary actions (31) and muscle reflexes (32). Two distinct aspects of anticipatory behaviour exist: what and when. The anticipation of emotional content (what) affects the startle reflex (33), and so does knowledge about the timing of the startling stimulus (when) (7). As indicated above, this project focuses on the temporal aspects of anticipation as a clear link between temporal predictability and neural oscillations exists (see Figure 3). Since the temporal predictability of the startling stimulus mitigates the startle reflex, one fundamental research question is: How does the brain use temporal knowledge to moderate an undesirable startle response? The answer to this question

There are two groups of reflexes in the human body, with two ways to categorize each of them. Reflexes can either be inborn and connected through the nervous system, or they can be learned through practice. Another way to explain a reflexive category would be autonomic reflexes or somatic reflexes. Autonomic reflexes are those which are unaware to us and act on visceral organs of the body, whereas somatic reflexes involve skeletal muscle stimulation. Both types of reflexes are put into effect via the nervous system. (1)