Why Do I React to an Email Before I've Finished Reading It?

An email arrives from a director you rarely hear from, with the subject line "Quick question." Your heart rate has risen before you open it, and by the third word of the first sentence a reply is forming. The reaction is already running, because the brain evaluates the first cues before it finishes reading the rest.

You react to an email before you finish reading it because the amygdala, a structure on each side of the brain, assigns significance to what you perceive (Sander, Grafman and Zalla, 2003) and starts a body response while the slower processing that reads meaning is still underway (LeDoux, 2014). Threat-related words alone activate it (Isenberg and colleagues, 1999).

Where Is the Amygdala and What Does It Do?

The amygdala is a cluster of nuclei deep in the temporal lobe, one on each side of the brain. Its circuits detect threats and control the body's defensive responses, and they do this without conscious involvement (LeDoux, 2014). One of its nuclei, the central nucleus, is the output region. Its connections run to the brainstem region that produces freezing, to the part of the hypothalamus that raises blood pressure and heart rate, and to the part that starts the pituitary-adrenal hormone chain (Phelps and LeDoux, 2005). The response those structures run is the one described in What Does Fight or Flight Mean at Work?. In the case of the director's email, the output had reached the heart before the subject line had been read to its end.

Why Do I React More to Some Senders than Others?

Because the amygdala responds to relevance, and relevance is personal. Threat is one of the things it detects. Sander, Grafman and Zalla (2003) reviewed the evidence and described the amygdala as a system for detecting events that matter to the person, with social relevance dominant in primates. Cunningham and Brosch (2012) reviewed evidence that its responses are tuned by a person's traits, needs, values, and goals, and that it responds to novel, ambiguous, and extremely positive events as well as threatening ones.

That tuning is why the same inbox produces different reactions in different people. A message from a director you rarely hear from is relevant on several counts at once. It is novel, it is ambiguous until read, and it concerns your standing, which in Sander's account is the category primates are most tuned to. A colleague who reports to that director, or who has never been evaluated by them, carries a different set of goals into the same inbox and may register nothing. The sender's name is a cue whose weight the person's own history has set.

How Fast Does the Amygdala Respond?

In direct recordings from the human amygdala, its response to a fearful face came earlier than the visual cortex's response to the same image. Méndez-Bértolo and colleagues (2016) recorded from the amygdala in patients who had electrodes implanted for epilepsy treatment. When the patients viewed fearful faces, the amygdala responded from 74 milliseconds after the face appeared, and it did so for fearful faces and not for neutral or happy ones.

Threat words also activate the amygdala. Isenberg and colleagues (1999) had participants name the color of printed words while their brains were scanned. Threat-related words produced greater activation in the amygdala on both sides than neutral words did, even though the task had nothing to do with the words' meaning. That study did not record timing. In a reading study using EEG, Kissler, Herbert, Peyk and Junghofer (2007) found that emotionally arousing words produced enhanced responses in the visual areas of the cortex 200 to 300 milliseconds after each word appeared, and the size of the response followed how arousing the word was.

Does the Signal Reach the Amygdala before the Rest of the Brain?

In 1996 Joseph LeDoux described two routes by which sensory information reaches the amygdala (LeDoux, 1996). On the first, which he called the low road, signals pass from the thalamus, the structure that routes incoming sensory signals, straight to the amygdala. On the second, the high road, they pass from the thalamus to the sensory cortex, which works out what the signal is, and then on to the amygdala. The low road is faster and carries a less detailed signal. The high road is slower and carries the detail. In LeDoux's account the amygdala can start a defensive response on the less detailed signal and revise it when the detailed one arrives.

Whether a dedicated route below the cortex carries such signals in humans is debated. Pessoa and Adolphs (2010) reviewed the evidence and argued that fast processing of emotional signals runs through multiple cortical pathways as well, so the two-road picture is a simplification. The direct recordings described above, in which the amygdala responded to a fearful face before the visual cortex did (Méndez-Bértolo and colleagues, 2016), used faces, and no equivalent recording exists for words. The order the recordings show is a fast first response followed by a slower, detailed one.

Why Does It React to Things That Turn Out to Be Harmless?

Because of how the response is set. The evolutionary biologist Randolph Nesse worked out the setting with signal-detection analysis and named it the smoke detector principle (Nesse, 2005; Nesse, 2001). A defensive response that costs little to run, against a threat that would cost a great deal if missed, should be set to trigger at the first sign of danger. A system set that way produces many false alarms, and natural selection favors it anyway, because one missed real threat outweighs many wasted responses.

Applied to email, the reaction to a director's name or a curt subject line is the expected output of a system set to respond early on incomplete information. Nesse's analysis covers defensive responses in general, including the ones that fire at a proposed change.

What Happens after the Amygdala Reacts?

The regions of the cortex that read meaning finish the sentence, take in the context, and revise the first reaction or sustain it. In the director's email, the revision arrives with the second sentence, which turns out to be a request for a meeting time. LeDoux (2014) describes the defensive circuit and the conscious evaluation as separate systems.

That revision depends on the prefrontal cortex, and its work is easiest when the body's response is small. Arnsten (2009), in a review drawing largely on animal studies, found that when stress hormone levels are high, prefrontal regulation weakens and the amygdala's influence on attention strengthens, so attention moves from what you intended to look at toward whatever is most noticeable, and the judgment that depends on the prefrontal cortex weakens with it.

What Else Is Connected to the Amygdala's Response?

Three connections matter for a working day.

Attention. The amygdala sends signals back to the sensory areas of the cortex that enhance the processing of emotionally significant events, especially threatening ones, a mechanism Vuilleumier (2005) calls emotional attention. It supplements the brain's deliberate control of attention and competes with it, and it is one mechanism by which the director's name holds attention while the rest of the inbox goes unread.

Memory. In a review drawing largely on animal studies, the hippocampus, the structure beside the amygdala that forms and retrieves memories, is disrupted by stress hormones, and the disruption is strongest when the amygdala and hippocampus are active together (Kim and Diamond, 2002). That is one mechanism behind losing a name or a figure in the middle of a tense conversation. The amygdala also strengthens memory for arousing events through the same hormones (Phelps and LeDoux, 2005), which is part of why an awkward meeting is replayed at night.

Sleep. Sleep loss changes the amygdala's own reactivity. In 26 adults, about 35 hours without sleep produced about 60 percent greater amygdala reactivity to negative pictures and reduced connectivity between the amygdala and the medial prefrontal cortex, the region that regulates it (Yoo, Gujar, Hu, Jolesz and Walker, 2007). After a bad night, the same email produces a larger first reaction and a weaker revision.

What Is an Amygdala Hijack?

Daniel Goleman's 1995 book Emotional Intelligence described moments when an emotional response takes over before deliberate thinking has caught up, which he called emotional hijacking (Goleman, 1995, Emotional Intelligence, Bantam). The shorter phrase amygdala hijack is his later shorthand for the same idea. As a description it is a metaphor. The amygdala does not seize control of the brain. It starts the body's response before the cortex has finished its evaluation, and the revision follows. The research since 1995 has changed the picture in the ways this post describes, and the moment itself, snapping in a meeting and regretting it later, is the hijack as people experience it.

Can the Brain Tell a Hostile Email from a Physical Threat?

A popular version of this topic says the brain cannot tell a tiger from a new piece of software, so it treats both the same. The evidence separates two things the claim runs together. The input differs. The laboratory work on what sets off the stress response found the strongest triggers in social situations, being judged by other people with no control over the outcome, with no physical danger present (Dickerson and Kemeny, 2004; the full account is in What Does Fight or Flight Mean at Work?). The amygdala is responding to a social cue, and the research on relevance detection above shows it is tuned to exactly that kind of cue.

The output is what is shared. The same output region drives the autonomic and hormonal response whichever kind of threat is detected, so the heart rate and the narrowed attention are the same in both cases. The claim is right about the output and wrong about the input, and a new system at work registers as a threat to standing and control, which is a social threat.

What the Amygdala Is

Amygdala: a cluster of nuclei deep in each temporal lobe that detects threats and other events relevant to the person and controls the body's defensive responses, without conscious involvement (LeDoux, 2014). It responds within a fraction of a second, before the cortical processing that reads meaning has finished, and it is tuned by the person's needs, values, and goals (Cunningham and Brosch, 2012).

Is the Amygdala the Brain's Fear Center?

No, and the correction comes from Joseph LeDoux, whose laboratory mapped the circuits through which the amygdala detects threat and drives the body's response. In 2014 he wrote that those circuits operate nonconsciously, that the conscious feeling of fear is a separate product of other processing, and that amygdala activity is therefore no signature of feeling afraid (LeDoux, 2014). With Daniel Pine he set out a two-system framework in which threat-elicited body responses and the conscious experience of fear arise from distinct circuits (LeDoux and Pine, 2016). That framework is debated (Fanselow and Pennington, 2018). The description that fits the evidence on both sides of the debate is a threat-detection circuit, and the history of the fear-center claim is where the two descriptions came apart.

The smoke detector comparison has a limit of its own. It describes the setting, easy to trigger, and it comes from Nesse's analysis of defenses in general (Nesse, 2005). The structure itself also responds to positive, novel, and ambiguous events (Cunningham and Brosch, 2012).

The next time an email produces a reaction before you have finished it, read to the end before you reply, and note which word or name started the reaction.

FAQ

Is it normal to react to an email before finishing it?

Yes. The amygdala responds to relevant cues within a fraction of a second, before the cortex has finished reading (LeDoux, 2014). Threat-related words activate it even when the task has nothing to do with their meaning (Isenberg and colleagues, 1999), and arousing words produce enhanced visual-cortex responses within a third of a second of appearing (Kissler and colleagues, 2007).

Does everyone's amygdala react the same way?

Its tuning varies from person to person. The amygdala's responses are shaped by a person's traits, needs, values, and goals (Cunningham and Brosch, 2012), so the sender who starts a reaction in you may start none in a colleague. Social relevance, meaning anything that concerns standing among other people, is the dominant category in primates (Sander, Grafman and Zalla, 2003).

What are the low road and the high road?

Two routes from the senses to the amygdala described by LeDoux (1996). The low road runs from the thalamus straight to the amygdala, fast and less detailed. The high road runs through the sensory cortex first, slower and detailed. Whether a dedicated subcortical route exists in humans is debated (Pessoa and Adolphs, 2010); the sequence of a fast first response and a slower revision is what the recordings show.

How does the amygdala hand off to slower thinking?

The cortical regions that read meaning finish the sentence and revise or sustain the first reaction, and this evaluation runs as a separate system from the detection (LeDoux, 2014). The handoff gets harder when stress hormone levels are high, because prefrontal regulation weakens and the amygdala's influence on attention strengthens (Arnsten, 2009).

Why does one bad night's sleep make me react more?

Because sleep loss raises the amygdala's reactivity and weakens its regulation. In 26 adults kept awake for about 35 hours, amygdala responses to negative pictures were about 60 percent larger than in rested participants, and connectivity between the amygdala and the medial prefrontal cortex was reduced (Yoo and colleagues, 2007).

What does the smoke detector principle describe?

The setting of a defensive response. Randolph Nesse showed with signal-detection analysis that a defense which costs little to run, against a threat that would cost a great deal if missed, should trigger at the first sign of danger, and that such a system produces many false alarms (Nesse, 2005). It applies to defenses in general.

What do people get wrong about the amygdala?

That it produces fear. Its circuits detect threat and drive defensive responses without conscious involvement, and LeDoux has written that its activity is no signature of feeling afraid (LeDoux, 2014). A second error is that it responds only to threat; it also responds to novel, ambiguous, and extremely positive events (Cunningham and Brosch, 2012). A third is that it cannot tell a social threat from a physical one; the strongest laboratory triggers are social (Dickerson and Kemeny, 2004).

What can I do about reacting before I finish reading?

Finish reading before you act. The first reaction is the detection system responding to a cue, and the revision comes from the cortex reading the whole message (LeDoux, 2014). The revision works best when the body's response is small, because high stress hormone levels weaken prefrontal regulation (Arnsten, 2009), and sleep loss reduces the regulating connection (Yoo and colleagues, 2007).

Related Posts:

What Does Fight or Flight Mean at Work?

Why Does My Body Stay Switched On after Work?

Why Do I Make Worse Decisions When I'm Stressed?

Why Is Change at Work So Hard?

What Happens in Your Body When Someone Says We Need to Talk?