Intermittent Reinforcement

Some people (ahem) check their personal email an absurd number of times per day. Sitting in front of a computer all day, it’s hard to resist checking for new messages, even if you just checked five minutes ago. In fact, it’s almost impossible. Why?

I think I know, and I think I learned it in Intro to Psych in 1999.

In the 1950s, behavioural psychologists experimented with learning by rewarding caged rats with a food pellet every time the rats pressed a lever. Although the rats initially only pressed the lever randomly or by mistake, they quickly learned the relationship between behaviour and reward and responded with frantic lever-pressing. In psych terms, the food reinforced the lever-pressing behaviour, that is, made it more likely to be repeated. Real-life examples of this kind of conditioning include rewarding your child with a new toy when he makes his bed or your company rewarding every two years of service with a pay increase. Toys and pay raises increase bed-making and company loyalty, respectively.

What does this have to do with email checking? Well, once the rats had clearly learned the relationship between lever-pressing and food, researchers started experimenting with the timing and probability of the reward. They wanted to know what would happen if they gave a rat a food pellet every third time it pressed the lever rather than every single time. Or if they provided food every 60 seconds no matter how many times the rat pressed the lever in the past minute. Or if the reward was completely random, that is, independent of timing and frequency of the behaviour. These variations are called reinforcement schedules. To their surprise, the researchers found that the most successful reinforcement schedule was intermittent reinforcement, that is, random and inconsistent reinforcement. This finding has since been widely replicated, in animals and humans, across situations and types of reward. 

Let’s go back to email checking now. You arrive at work in the morning and check your personal email first thing. You have a bunch of new messages. When you check again 15 minutes later, you have two more new messages. The next three times you check, there’s nothing. After lunch, still nothing. But an hour later, in mid-afternoon, you sign in again and bingo–you’re rewarded with 3 new messages! Yessss!! You feel pleased and validated because all your hard email-checking work paid off. You read your messages, respond or delete, and return to work. But 15 minutes later you have the urge to check your email again. You're in the clutches of email's inherently intermittent reinforcement!

Question: Is it disturbing or reassuring to realize that your personal behaviour is governed by basic principles of learning theory that apply to all people? And, um, all rats.

Twilight Zone

Seasonal Affective Disorder (SAD) is a mood disorder in which people whose mental health is stable for most of the year experience depressive symptoms during the winter months. But what about the short-term anxiety, disorientation, or melancholy that you feel in the winter around 4pm when the light starts to change? At first I thought it was just me, but the fleeting depressive state that occurs at dusk is a legitimate phenomenon (although not included in the DSM) and it has a name. It's called Hesperian depression, after the moment when the Greek God Hesperus, the evening star, rises in the sky. 

I've discovered that the best way to combat Hesperian depression is to be doing something at that time other than staring out the window at the darkening sky. For me, the best thing is to go for a run, but a phone call to a friend, a coffee break, or some other quick and pleasant distraction will also do the trick. By the time you're done, darkness will have fallen completely, Hesperus' rise will be complete, and that uncomfortable twilight period will be over.

The DSM

First published in 1952, the Diagnostic and Statistical Manual of Mental Disorders (DSM) is the diagnostic reference manual used by psychologists, psychiatrists, and other mental health clinicians in North America. The manual lists all the different depressive disorders, anxiety disorders, substance-related disorders, psychotic disorders, eating disorders, impulse control disorders, sexual and gender identity disorders, and personality disorders, among others. Each disorder is described by a set of diagnostic criteria.

What’s good and bad about the DSM?

Let's start with the good. First, the manual creates a common language for professionals. If I tell my client’s GP that the client has panic disorder, the doctor knows what I’m talking about. Second, a DSM diagnosis provides validation for clients; if you think you’re going crazy, it can be a relief to hear that your problem is a documented phenomenon. Third, DSM criteria are helpful in recruiting participants for psychiatric research. When you read an ad for individuals who experience recurrent and persistent intrusive thoughts or impulses and repetitive behaviours that they perform in response to an obsession, you’re reading the DSM criteria for obsessive-compulsive disorder.

What are the problems with the DSM? One of the biggest criticisms is that a DSM diagnosis is stigmatizing--a valid point. For example, if you have a major depressive episode documented in your medical file, your insurance carrier might consider you a suicide risk and raise your life insurance rate. If your file says that you have a personality disorder, some therapists may hesitate to accept you as a client. For this reason, as psychology interns, we are taught to be very careful what we write in client files.

A second criticism of the DSM is that it’s categorical and the diagnostic thresholds are arbitrary. I’ll use the diagnostic criteria for post-traumatic stress disorder (PTSD) as an example. You might have experienced a traumatic event and responded with intense fear, helplessness, or horror (criterion A). You may re-experience the event through flashbacks, nightmares, or memories (criterion B) and avoid people or places associated with the trauma (criterion C). But if you don’t experience arousal symptoms such as angry outbursts and sleep disturbances (criterion D), according to the DSM, you don't have PTSD. Without a DSM diagnosis, you may be denied access to specialized treatment, and your insurance company may decline to reimburse your therapy fees.

A final point to consider about the DSM is that the inclusion of a given condition constitutes an indicator of how that condition is viewed by society. Infamously, homosexuality was included in the DSM up until the 1980s. Today, there is heated debate about whether or not Gender Identity Disorder (the feeling that your physical gender does not match your true gender) is a real disorder and if so, whether or not the DSM should change the name to the less pejorative “Gender Incongruence.”

The edition in current use is DSM-IV-TR (text revision), published in 2000, but DSM-V is to be published in 2012. In preparation, working groups at the American Psychiatric Association are making decisions about such proposed additions as binge eating disorder, Internet addiction, and premenstrual dysphoric disorder.

Stay tuned.

What's the difference?

What's the difference between a psychologist and a psychiatrist?

A psychiatrist is a person who went to medical school and chose to specialize in psychiatry rather than pediatrics, oncology, or another medical specialization. Psychiatrists are doctors and they can prescribe drugs. In contrast, a psychologist is a person who completed a PhD in psychology (although in Quebec prior to 2006, a psychologist could be granted a license with a master's degree).

The reason it's confusing is that both professionals do mental health research, see patients in clinic or hospital settings, and teach in universities. And, although therapy is usually the province of psychologists, some psychiatrists conduct therapy as well. 

What's a psychotherapist, then? Enter further complication. Until recently, the title “psychotherapist” was not protected in Quebec and no regulations governed its practice. Any psychologist, psychiatrist, doctor, nurse, social worker, sexologist—or for that matter, any software developer, construction worker, or event planner—could advertise himself or herself as a therapist. However, the term "psychotherapist" became regulated in 2012, and the right to practice psychotherapy and the use of the title psychotherapist is now restricted to psychologists and members of certain other professional orders. This legislation is good news for the public because it prevents individuals who are not adequately trained from providing psychotherapy.

Sometimes when I tell people I'm a psychologist, they say "Oh wow, I bet you're reading my mind right now!" This is a whole other level of confusion wherein psychologists are mistaken for psychics.

In sum, psychiatrists are doctors; psychologists are PhDs; psychotherapists (in Quebec) are psychoeducators, nurses, guidance counsellors, social workers, and occupational therapists, among others; and no one can read your mind. Now go forth and impress mental health professionals with your advanced understanding of the differences between professions!