How reliable is our memory under conditions of stress?

In an earlier entry about false confessions, I briefly touched upon the topic of how memory works. The way it works barely resembles the way artificial memory systems work. Rather than accurately retrieving information, we reconstruct our memories every time we recall them.

The topic of memory, just like many other Psychology topics, is subjected to a lot of misconceptions and myths. The way we collect, store and recall memories is extremely complex with different factors like emotional activation or information type playing an important role.

How do emotions affect our memories?

It is a widespread idea that emotions have a strong effect on memory. As early as the inception of psychoanalysis, its proponents theorized that memories of traumatic experiences or emotionally disturbing events tended to be repressed. Despite the fact that repressed memories are still a popular concept, the actual incidence of repressed memories is very small. So much so, that many psychologists believe they should not be considered a real phenomenon.

Oddly enough, the belief that emotionally charged events are more memorable is also a common idea. So, what truth is there to these popular assumptions?


There is considerable scientific evidence that proves that information with emotional content is remembered more vividly than neutral information. [1] This happens not only with autobiographical memories – important events in our lives- but also with information provided in a lab in the course of an experiment.

Emotional information is remembered more accurately because of two special features that make its initial encoding more effective; valence and arousal. Emotional information, as opposed to neutral one, is evaluated by us as either positive or negative (valence). Emotional information also provides some type of physiological and psychological activation; having a soothing or agitating effect on us (arousal). Information is more effectively encoded when processed in this context of activation and interpretation as it helps us to combine new information with already existing memories.

Unreliable accounts

If emotionally charged memories seem to be remembered better than neutral ones, why are people so unreliable when retelling an emotional story?

Even though emotional events are generally remembered better than neutral ones, very intense emotional activation can make people forget details. Intense activation leads to attention narrowing which makes us focus on the central aspects of an event, ignoring the secondary details.

The Yerkes–Dodson curve; a classic, empirical law that dictates that performance increases with physiological or mental arousal, but only up to a point, can explain the difference in accuracy of memories on subjects under stress. When a certain point of activation is reached, performance decreases.

Yerkes-Dodson curve

The case of eyewitness testimony

The study of memory accuracy is of extreme importance to the field of Forensic Psychology. Eyewitness testimony plays a vital role in countless criminal investigations and court proceedings but the question that I get often times is; how reliable is eyewitness testimony?

Regarding eyewitnesses to a crime or accident, we should understand that they can vividly remember a given event and its most important features but; depending on their physiological activation, they won’t be able to give specific details about secondary aspects. Collateral information like the physical appearance of an aggressor or the color and size of certain objects won’t be stored accurately.

It seems to be the case that right after experiencing a traumatic event, only essential information is remembered. In the hours or days following the event, some secondary details and collateral information can be recovered and remembered.

The problem comes when an overzealous investigator questions a witness, providing details with their questions, which the subject can then incorporate into their own recollection, leading to inaccurate testimonies.

So in short, the accuracy of memories in the context of stressful events depends on:

  • The level of activation of the subject.
  • The amount of time that has elapsed since the event.
  • How the person is being questioned.

What could be done about this?

Interrogation techniques need to be refined. Not only police investigators need to formulate neutral and simple questions that don’t provide any information or opinion regarding the case. Also, the questioning by lawyers and prosecutors can alter a testimony, so they should be conducted carefully as well. When it comes to recognizing suspects, police lineups should be conducted similarly to how a scientific investigation, making use of double blinds and preventing anyone from giving any hints to the person doing the identification.

[1] Remembering emotional events. A. Burke (1992)


The Psychology of Emotions

Emotions are, alongside personality, the psychology topic, we more often refer to in our daily lives. We talk about how we feel -or felt- in a certain situation and how those emotions influence our conduct and choices.

Experimental research in the field of psychology and neuroscience has provided us with a deeper understanding of emotions and how they affect us. The general agreement among researchers is that there are six basic emotions: happiness, sadness, anger, disgust, fear, and surprise. They are considered our basic (or primary) emotions because they seem to be present cross-culturally. Another important feature of basic emotions is that each of them is associated with a specific pattern of physiological activity and facial expression.

It seems obvious that we experience a wider range of emotions than those basic ones. Complex or secondary emotions -like annoyance or envy- are made up of basic emotions and probably came about, and stayed with us, by way of cultural conditioning and association.

Psychologist Robert Plutchik proposes a model with eight primary and contrasting emotions.
The function of emotions

Emotion is undoubtedly a defining aspect of humans and animals, and a factor that (still) differentiate us from machines. Emotions also have a profound effect on our thoughts and actions which can lead to both a positive and negative outcomes.

So, apart from making us what we are, do emotions serve us a purpose? Yes, they do. Emotions have an important adaptive role as they get us ready for action when it’s most needed. A good example of this would be fear. We experience fear when we perceive a danger or imminent threat. In this case, the flight-or-fight response is triggered making us more alert, shifting our attention to negative stimuli and preparing the body -increased muscle tension, blood flow- to fight or escape.

However, a lengthy state of fear will have negative consequences. If a person is worried about losing their job and experiences it with fear and intense anxiety, the emotional response will probably be prolonged in time. Such person won’t be able to focus on their daily tasks and will have trouble sleeping at night because of this emotional activation.

Emotional biases

Emotional states can cause cognitive and memory biases. A clear example is how anger clouds our judgment and keeps us from making rational decisions. When it comes to processing information, we prioritize the emotionally-charged stimuli over neutral ones. Emotions can also alter the content of our memories as well as how or when a memory is recalled. Memories consistent with our current emotional state are more easily accessible.

The effect of emotional states on cognition and memory is a broad field of research. It is also of vital importance to clinical psychologists as it helps us understand how the minds of those battling anxiety or depression work.

Human emotion is fundamental to the study and treatment of mental disorders as well as to the understanding of human cognition and behavior.

It’s not me: it’s them!

If I ask you “Why do you think you haven’t gotten a promotion?” or “Why do you think you did well in school?”, you might say “Because my boss doesn’t like me” or “Because I got a lot of help from my parents”. Someone else might answer “I haven’t gotten a promotion because I’m not ready for one yet” or “I worked really hard for my grades”. The truth is that the real causes of these events are probably complex and varied but we all have a particular way of thinking about them. We all have an attributional style. And they way we think about them has an impact on our behavior and self-esteem.

Attributional or explanatory style refers to the way in which we evaluate and explain events in our lives. It consists of three dimensions: locus of control, stability, and scope.

The locus of control is probably the most talked-about element of this theory. Locus is Latin for ‘place’ or ‘location’ and locus of control refers to where we think the control over the outcomes of our life lies. People with a strong internal locus of control will believe that their life events are the result of their own actions and choices exclusively. Contrariwise, a person with a strong external locus of control will think that external factors (the doing of others, their environment or plain luck) are in charge of the outcomes of their life. Just like personality dimensions, the locus of control is not an “either/or” typology, we all fall somewhere along a continuum of internal/external attribution.

The stability dimension refers to whether someone believes that the cause of outcome is stable or unstable. For example, luck is usually seen as unstable while ability or intelligence will be considered stable.

The last dimension -that I chose to call scope– refers to whether the explanation that the subject gives to an event is generalized to other events or only applies to the event at hand. For example, a person might think they only have luck with relationships but not with money.



The ‘optimal’ attributional style

At this point, you might be wondering: what would the optimal attributional style be? The answer is not so easy but let’s take a look at these two ‘extremes’:


The pessimist believes that failures are their own doing as well as stable and generalized to all possible events. Their successes are however external -nothing to do with them- unstable and specific to certain events. A pessimistic attributional style seems to correlate with depression and physical illness.

The optimist considers their failures are due to external causes that are (luckily!) unstable and specific to some events. Their successes are due to an internal factor -their own choice or their own behavior- that is also stable and generalizable to any event.

Effects of attributional styles

There has been extensive research about the effects of attributional styles on academic performance, health-related behaviors, and job performance. In general, students with an internal attributional style seem to perform better academically. Students with an external attributional style tend to receive lower grades, as they believe there is nothing they can do to do better in school.

There also seems to be a link between an internal locus of control and preventive health behaviors like exercise, breast self-examination, and weight control. People who believe they are in control of their own health, are more inclined to take up healthy habits than those who don’t.

Try to understand your own locus of control by taking this quiz.

Interesting reads:
Oettingen, G. (1995). Explanatory style in the context of culture
Tam Shui Kee Tony (2003) Locus of control, attributional style and discipline problems in secondary schools

Is winter blues “a thing”?

Once the holiday season is over and we are faced with the beginning of a new year, it is common to feel down or generally unhappy. Daylight plunges, vacation days are scarce during Q1 and we are often confronted with the many demands of our New Year’s resolutions. It is no wonder we feel off and distressed. This feeling is very common and normal. Today I’d like to write about how this temporary state of general unhappiness differs from a full-fledged mood disorder also known as Seasonal affective disorder (SAD) or Seasonal Depression.

winter blues
Source: 9gag


The psychopathology of seasonal depression

Seasonal affective disorder, first described in 1984 by Norman E. Rosenthal, has been considered both a unique mood disorder and a modifier -or specifier- of a recurrent depressive disorder that occurs with a seasonal pattern. In short, there are two lines of thinking about seasonal depression; those who consider it an independent disorder and those who prefer to think of it as a modifier -a special characteristic- of a major depressive disorder.

The proponents of SAD as a unique entity, support their claims with biological studies. Patients affected by a depressive disorder with seasonal pattern, have problems processing visual light, usually, develop their symptoms when adequate light is not present and respond favorably to light therapy.

Those who prefer the SAD to remain as a major depressive disorder with seasonal pattern, claim that patients diagnosed with winter depression suffer recurrent episodes of major depression. Their symptoms seem to increase during the fall and winter and decrease with the coming of spring and summer.

Diagnosis of a depressive disorder

At this point, I would like to talk about the criteria for the diagnosis of a depressive disorder. The DSM-V (The Diagnostic and Statistical Manual of Mental Disorders) indicates that 5 or more of the following symptoms need to have been present during a same 2-week period. At least one of the symptoms has to be number 1 or 2.

  1. Depressed mood most of the day, nearly every day (self-reported or observation made by others).
  2. Markedly diminished interest or pleasure in all, or almost all, activities most of the
    day, nearly every day (as indicated by either subjective account or observation).
  3. Significant weight loss when not dieting or weight gain (e.g., a change of more than
    5% of body weight in a month), or decrease or increase in appetite nearly every day.
  4. Insomnia or hypersomnia nearly every day.
  5. Psychomotor agitation or retardation nearly every day (observable by others, not
    merely subjective feelings of restlessness).
  6. Fatigue or loss of energy nearly every day.
  7. Feelings of worthlessness or excessive or inappropriate guilt nearly every day.
  8. Diminished ability to think or concentrate, or indecisiveness, nearly every day.
  9. Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.

These symptoms cannot be attributed to another medical condition and cause significant stress as well as social and occupational impairment. If in the last 2-year period, two episodes of major depression have occurred and remitted in specific times of the year, we can speak about seasonal depression.

As you can see, the actual diagnosis of winter depression, it’s more complex than what many articles written these days would lead you to believe. I encourage anyone who recognizes the preceding symptoms in themselves to seek professional help. If you are just feeling down or overwhelmed these days, I will offer some tips about how to overcome the winter blues in my next post.

Article about seasonal disorders

(This post was originally published on on January 10th, 2017)